MDEV-24962: Galera SST innobackupex-move ignores Environment settings

After switching to the new mariabackup interface (instead of
the outdated innobackupex interface, which is supported for
compatibility), we need to explicitly pass a path to the datadir
directory as a parameter, since in the new interface the value
of this option is not automatically set in such a way that it
always matches the SST/IST logic. This commit adds passing this
option as an explicit parameter to mariabackup. This commit also
removed unnecessary options that are not used and not supported
by mariabackup.

Also, numerous flaws in the common wsrep_sst_common script have
been fixed:

 1) There are many bash-specific constructs in the script that
    may not be supported by other interpreters, which can lead
    to the most unexpected errors during SST, because failures
    in the interpretation of bash-specific constructs lead to
    incorrect parsing of arguments;
 2) There is parse_cnf() function which is often called by other
    scripts for the "mysqld" or "--mysqld" group, but it does not
    take into account the default group suffix, which leads to
    reading values only from the default group, which then leads
    to errors due to reading the default values instead of the
    values for a specific group;
 3) Some options such as --user, --innodb-data-home-dir or --datadir
    are not removed from the --mysqld-args list, although they are
    processed inside scripts (and passing of these options funther
    may cause problems for mariabackup);
 4) If an argument that the script understands is present in
    the --mysqld-args list twice, then this causes SST to fail,
    instead of reading the most recent value;
 5) The "--host" parameter is technically still supported among
    the arguments of the SST scripts, but in reality scripts do not
    work with it as expected, especially if it has an IPv6 address;
 6) If the port number is absent in the --address parameter value,
    but the port number is explicitly passed through the --port
    argument, then the scripts for mariabackup and xtrabackup-v2
    fail;
 7) If a new address interface is used (with the --address parameter),
    then automatic default port substitution is not performed, although
    it is supported for the legacy --host/--port interface.
 8) If there are spaces in the parameter values after --mysqld_args,
    then their further transfer does not occur correctly, which
    causes mariabackup to fail during SST - the space splits
    the argument in such a way that it breaks the parsing of the
    following parameters;
 9) If most of the parameters that are names or paths to the files
    or directories contain spaces, then SST scripts fail in an
    unpredictable way due to incorrect variable substitutions;
10) If the --log-bin option is passed among the arguments of myqlds
    (--mysqld-args) without a parameter, and the --binlog option
    is not specified, then the script cannot substitute the default
    name for binlog and cannot construct binlog name using the
    --log-basename argument (which is against server specifications);
11) Tail slashes are not removed from the directory names, which,
    upon further substitution, leads to the appearance of a double
    slash in the file paths;
12) The explicit --binlog parameter (which is now always transmitted
    from the server side) and the "hidden" --log-bin parameter in the
    list of arguments after --mysqld-args are perceived as two different
    parameters in different parts of the scripts, and if they are do not
    match for some reason, this will lead to failures during SST;

Also, all new changes from the 10.6 branch have been migrated here,
including the latest pull requests for authentication (only the part
that concerns SST scripts).

It also fixes dozens of other bugs in all SST scripts.

7 files changed, 1177 insertions, 792 deletions

diff --git a/mysql-test/suite/galera/r/galera_ssl_upgrade.result b/mysql-test/suite/galera/r/galera_ssl_upgrade.result
index 8aab135c6a2..1443e34d041 100644
--- a/mysql-test/suite/galera/r/galera_ssl_upgrade.result
+++ b/mysql-test/suite/galera/r/galera_ssl_upgrade.result
@@ -1,10 +1,3 @@
-call mtr.add_suppression("WSREP: write_handler(): protocol is shutdown");
-SELECT VARIABLE_VALUE = 'Synced' FROM INFORMATION_SCHEMA.GLOBAL_STATUS WHERE VARIABLE_NAME = 'wsrep_local_state_comment';
-VARIABLE_VALUE = 'Synced'
-1
-SELECT VARIABLE_VALUE = 2 FROM INFORMATION_SCHEMA.GLOBAL_STATUS WHERE VARIABLE_NAME = 'wsrep_cluster_size';
-VARIABLE_VALUE = 2
-1
 connection node_1;
 call mtr.add_suppression("WSREP: write_handler(): protocol is shutdown.*");
 connection node_2;
@@ -12,6 +5,14 @@ call mtr.add_suppression("WSREP: write_handler(): protocol is shutdown.*");
 connection node_1;
 connection node_2;
 connection node_1;
+connection node_2;
+SELECT VARIABLE_VALUE = 'Synced' FROM INFORMATION_SCHEMA.GLOBAL_STATUS WHERE VARIABLE_NAME = 'wsrep_local_state_comment';
+VARIABLE_VALUE = 'Synced'
+1
+SELECT VARIABLE_VALUE = 2 FROM INFORMATION_SCHEMA.GLOBAL_STATUS WHERE VARIABLE_NAME = 'wsrep_cluster_size';
+VARIABLE_VALUE = 2
+1
+connection node_1;
 SELECT VARIABLE_VALUE = 2 FROM INFORMATION_SCHEMA.GLOBAL_STATUS WHERE VARIABLE_NAME = 'wsrep_cluster_size';
 VARIABLE_VALUE = 2
 1
@@ -23,3 +24,5 @@ connection node_1;
 SELECT VARIABLE_VALUE = 2 FROM INFORMATION_SCHEMA.GLOBAL_STATUS WHERE VARIABLE_NAME = 'wsrep_cluster_size';
 VARIABLE_VALUE = 2
 1
+disconnect node_2;
+disconnect node_1;
diff --git a/mysql-test/suite/galera/t/galera_ssl_upgrade.test b/mysql-test/suite/galera/t/galera_ssl_upgrade.test
index 146a0126f1f..c4ad652a482 100644
--- a/mysql-test/suite/galera/t/galera_ssl_upgrade.test
+++ b/mysql-test/suite/galera/t/galera_ssl_upgrade.test
@@ -8,16 +8,16 @@
 --source include/have_innodb.inc
 --source include/have_ssl_communication.inc
 
-call mtr.add_suppression("WSREP: write_handler(): protocol is shutdown");
-
-SELECT VARIABLE_VALUE = 'Synced' FROM INFORMATION_SCHEMA.GLOBAL_STATUS WHERE VARIABLE_NAME = 'wsrep_local_state_comment';
-SELECT VARIABLE_VALUE = 2 FROM INFORMATION_SCHEMA.GLOBAL_STATUS WHERE VARIABLE_NAME = 'wsrep_cluster_size';
-
 --connection node_1
 call mtr.add_suppression("WSREP: write_handler(): protocol is shutdown.*");
 --connection node_2
 call mtr.add_suppression("WSREP: write_handler(): protocol is shutdown.*");
 
+# Save original auto_increment_offset values.
+--let $node_1=node_1
+--let $node_2=node_2
+--source include/auto_increment_offset_save.inc
+
 # Setup galera ports
 --connection node_1
 --source suite/galera/include/galera_base_port.inc
@@ -27,6 +27,9 @@ call mtr.add_suppression("WSREP: write_handler(): protocol is shutdown.*");
 --source suite/galera/include/galera_base_port.inc
 --let $NODE_GALERAPORT_2 = $_NODE_GALERAPORT
 
+SELECT VARIABLE_VALUE = 'Synced' FROM INFORMATION_SCHEMA.GLOBAL_STATUS WHERE VARIABLE_NAME = 'wsrep_local_state_comment';
+SELECT VARIABLE_VALUE = 2 FROM INFORMATION_SCHEMA.GLOBAL_STATUS WHERE VARIABLE_NAME = 'wsrep_cluster_size';
+
 # 2. Restart node #1 with a socket.ssl_ca that includes both the new and the old certificate
 
 --connection node_1
@@ -40,7 +43,7 @@ call mtr.add_suppression("WSREP: write_handler(): protocol is shutdown.*");
 --source include/wait_condition.inc
 SELECT VARIABLE_VALUE = 2 FROM INFORMATION_SCHEMA.GLOBAL_STATUS WHERE VARIABLE_NAME = 'wsrep_cluster_size';
 
-# 3. Restart node #2 with the new socket.ssl_ca , socket.ssl_cert and socket.ssl_key 
+# 3. Restart node #2 with the new socket.ssl_ca , socket.ssl_cert and socket.ssl_key
 
 --connection node_2
 --source include/shutdown_mysqld.inc
@@ -52,7 +55,7 @@ SELECT VARIABLE_VALUE = 2 FROM INFORMATION_SCHEMA.GLOBAL_STATUS WHERE VARIABLE_N
 --source include/wait_condition.inc
 SELECT VARIABLE_VALUE = 2 FROM INFORMATION_SCHEMA.GLOBAL_STATUS WHERE VARIABLE_NAME = 'wsrep_cluster_size';
 
-# 4. Restart node #1 with the new socket.ssl_ca , socket.ssl_cert and socket.ssl_key 
+# 4. Restart node #1 with the new socket.ssl_ca , socket.ssl_cert and socket.ssl_key
 
 --connection node_1
 --source include/shutdown_mysqld.inc
@@ -69,3 +72,8 @@ SELECT VARIABLE_VALUE = 2 FROM INFORMATION_SCHEMA.GLOBAL_STATUS WHERE VARIABLE_N
 --source include/galera_wait_ready.inc
 
 # Upgrade complete. Both nodes now use the new key and certificate
+
+# Restore original auto_increment_offset values.
+--source include/auto_increment_offset_restore.inc
+
+--source include/galera_end.inc
diff --git a/mysql-test/suite/galera_3nodes/disabled.def b/mysql-test/suite/galera_3nodes/disabled.def
index 2ab0886a427..8b7f8109b43 100644
--- a/mysql-test/suite/galera_3nodes/disabled.def
+++ b/mysql-test/suite/galera_3nodes/disabled.def
@@ -5,17 +5,13 @@
 #  Separate the test case name and the comment with ':'.
 #
 #    <testcasename> : MDEV-<xxxx> <comment>
-# 
+#
 #  Do not use any TAB characters for whitespace.
 #
 ##############################################################################
 
 GAL-501 : MDEV-24645 galera_3nodes.GAL-501 MTR failed: failed to open gcomm backend connection: 110
 galera_gtid_2_cluster : MDEV-23775 Galera test failure on galera_3nodes.galera_gtid_2_cluster
-galera_ipv6_mariabackup : MDEV-24440: galera_3nodes.galera_ipv6_mariabackup MTR fails sporadically: Failed to read from: wsrep_sst_mariabackup --role 'donor' --address '[::1]:16028/xtrabackup_sst//1'
-galera_ipv6_mariabackup_section : MDEV-22195: galera_3nodes.galera_ipv6_mariabackup_section MTR failed: assert_grep.inc failed
-galera_ipv6_mysqldump : MDEV-24036: galera_3nodes.galera_ipv6_mysqldump: rare random crashes during shutdown
-galera_ipv6_rsync_section : MDEV-23580: galera_3nodes.galera_ipv6_rsync_section MTR failed: WSREP_SST: [ERROR] rsync daemon port '16008' has been taken
 galera_ist_gcache_rollover : MDEV-23578 WSREP: exception caused by message: {v=0,t=1,ut=255,o=4,s=0,sr=0,as=1,f=6,src=50524cfe,srcvid=view_id(REG,50524cfe,4),insvid=view_id(UNKNOWN,00000000,0),ru=00000000,r=[-1,-1],fs=75,nl=(}
 galera_load_data_ist :  MDEV-24639 galera_3nodes.galera_load_data_ist MTR failed with SIGABRT: query 'reap' failed: 2013: Lost connection to server during query
 galera_load_data_ist :  MDEV-24639 galera_3nodes.galera_load_data_ist MTR failed with SIGABRT: query 'reap' failed: 2013: Lost connection to server during query
diff --git a/scripts/wsrep_sst_common.sh b/scripts/wsrep_sst_common.sh
index e05e530f6f9..9e6807e20a3 100644
--- a/scripts/wsrep_sst_common.sh
+++ b/scripts/wsrep_sst_common.sh
@@ -1,4 +1,5 @@
 # Copyright (C) 2012-2015 Codership Oy
+# Copyright (C) 2017-2021 MariaDB
 #
 # This program is free software; you can redistribute it and/or modify
 # it under the terms of the GNU General Public License as published by
@@ -21,26 +22,32 @@ set -u
 WSREP_SST_OPT_BYPASS=0
 WSREP_SST_OPT_BINLOG=""
 WSREP_SST_OPT_BINLOG_INDEX=""
+WSREP_SST_OPT_LOG_BASENAME=""
 WSREP_SST_OPT_DATA=""
-WSREP_SST_OPT_AUTH=${WSREP_SST_OPT_AUTH:-}
-WSREP_SST_OPT_USER=${WSREP_SST_OPT_USER:-}
-WSREP_SST_OPT_PSWD=${WSREP_SST_OPT_PSWD:-}
-WSREP_SST_OPT_REMOTE_AUTH=${WSREP_SST_OPT_REMOTE_AUTH:-}
+WSREP_SST_OPT_AUTH="${WSREP_SST_OPT_AUTH:-}"
+WSREP_SST_OPT_USER="${WSREP_SST_OPT_USER:-}"
+WSREP_SST_OPT_PSWD="${WSREP_SST_OPT_PSWD:-}"
+WSREP_SST_OPT_REMOTE_AUTH="${WSREP_SST_OPT_REMOTE_AUTH:-}"
 WSREP_SST_OPT_DEFAULT=""
 WSREP_SST_OPT_EXTRA_DEFAULT=""
 WSREP_SST_OPT_SUFFIX_DEFAULT=""
 WSREP_SST_OPT_SUFFIX_VALUE=""
 WSREP_SST_OPT_MYSQLD=""
-INNODB_DATA_HOME_DIR_ARG=""
-INNODB_LOG_GROUP_HOME_ARG=""
-INNODB_UNDO_DIR_ARG=""
-LOG_BIN_ARG=""
-readonly WSREP_SST_OPT_REMOTE_AUTH
+WSREP_SST_OPT_PORT=""
+WSREP_SST_OPT_ADDR=""
+WSREP_SST_OPT_ADDR_PORT=""
+WSREP_SST_OPT_HOST=""
+WSREP_SST_OPT_HOST_UNESCAPED=""
+WSREP_SST_OPT_HOST_ESCAPED=""
+INNODB_DATA_HOME_DIR="${INNODB_DATA_HOME_DIR:-}"
+INNODB_LOG_GROUP_HOME="${INNODB_LOG_GROUP_HOME:-}"
+INNODB_UNDO_DIR="${INNODB_UNDO_DIR:-}"
+INNOEXTRA=""
 
 while [ $# -gt 0 ]; do
 case "$1" in
     '--address')
-        readonly WSREP_SST_OPT_ADDR="$2"
+        WSREP_SST_OPT_ADDR="$2"
         #
         # Break address string into host:port/path parts
         #
@@ -48,60 +55,61 @@ case "$1" in
         \[*)
             # IPv6
             # Remove the starting and ending square brackets, if present:
-            addr_no_bracket=${WSREP_SST_OPT_ADDR#\[}
-            readonly WSREP_SST_OPT_HOST_UNESCAPED=${addr_no_bracket%%\]*}
-            # Square brackets are needed in most cases:
-            readonly WSREP_SST_OPT_HOST="[${WSREP_SST_OPT_HOST_UNESCAPED}]"
+            addr_no_bracket="${WSREP_SST_OPT_ADDR#\[}"
             # Some utilities and subsequent code require an address
             # without square brackets:
+            readonly WSREP_SST_OPT_HOST_UNESCAPED="${addr_no_bracket%%\]*}"
+            # Square brackets are needed in most cases:
+            readonly WSREP_SST_OPT_HOST="[${WSREP_SST_OPT_HOST_UNESCAPED}]"
             readonly WSREP_SST_OPT_HOST_ESCAPED="\\[${WSREP_SST_OPT_HOST_UNESCAPED}\\]"
+            # Mark this address as IPv6:
             readonly WSREP_SST_OPT_HOST_IPv6=1
             ;;
         *)
-            readonly WSREP_SST_OPT_HOST=${WSREP_SST_OPT_ADDR%%[:/]*}
-            readonly WSREP_SST_OPT_HOST_UNESCAPED=$WSREP_SST_OPT_HOST
-            readonly WSREP_SST_OPT_HOST_ESCAPED=$WSREP_SST_OPT_HOST
+            readonly WSREP_SST_OPT_HOST="${WSREP_SST_OPT_ADDR%%[:/]*}"
+            readonly WSREP_SST_OPT_HOST_UNESCAPED="$WSREP_SST_OPT_HOST"
+            readonly WSREP_SST_OPT_HOST_ESCAPED="$WSREP_SST_OPT_HOST"
             readonly WSREP_SST_OPT_HOST_IPv6=0
             ;;
         esac
         # Let's remove the leading part that contains the host address:
-        remain=${WSREP_SST_OPT_ADDR#${WSREP_SST_OPT_HOST_ESCAPED}}
+        remain="${WSREP_SST_OPT_ADDR#$WSREP_SST_OPT_HOST_ESCAPED}"
         # Let's remove the ":" character that separates the port number
         # from the hostname:
-        remain=${remain#:}
+        remain="${remain#:}"
         # Extract the port number from the address - all characters
         # up to "/" (if present):
-        readonly WSREP_SST_OPT_ADDR_PORT=${remain%%/*}
+        WSREP_SST_OPT_ADDR_PORT="${remain%%/*}"
         # If the "/" character is present, then the path is not empty:
         if [ "${remain#*/}" != "${remain}" ]; then
             # This operation removes everything up to the "/" character,
             # effectively removing the port number from the string:
-            readonly WSREP_SST_OPT_PATH=${remain#*/}
+            readonly WSREP_SST_OPT_PATH="${remain#*/}"
         else
             readonly WSREP_SST_OPT_PATH=""
         fi
         # The rest of the string is the same as the path (for now):
-        remain=${WSREP_SST_OPT_PATH}
+        remain="${WSREP_SST_OPT_PATH}"
         # If there is one more "/" in the string, then everything before
         # it will be the module name, otherwise the module name is empty:
         if [ "${remain%%/*}" != "${remain}" ]; then
             # This operation removes the tail after the very first
             # occurrence of the "/" character (inclusively):
-            readonly WSREP_SST_OPT_MODULE=${remain%%/*}
+            readonly WSREP_SST_OPT_MODULE="${remain%%/*}"
         else
             readonly WSREP_SST_OPT_MODULE=""
         fi
         # Remove the module name part from the string, which ends with "/":
-        remain=${WSREP_SST_OPT_PATH#*/}
+        remain="${WSREP_SST_OPT_PATH#*/}"
         # If the rest of the string does not match the original, then there
         # was something else besides the module name:
         if [ "$remain" != "${WSREP_SST_OPT_PATH}" ]; then
             # Extract the part that matches the LSN by removing all
             # characters starting from the very first "/":
-            readonly WSREP_SST_OPT_LSN=${remain%%/*}
+            readonly WSREP_SST_OPT_LSN="${remain%%/*}"
             # Exctract everything after the first occurrence of
             # the "/" character in the string:
-            remain=${remain#*/}
+            remain="${remain#*/}"
             # If the remainder does not match the original string,
             # then there is something else (the version number in
             # our case):
@@ -109,7 +117,7 @@ case "$1" in
                 # Let's extract the version number by removing the tail
                 # after the very first occurence of the "/" character
                 # (inclusively):
-                readonly WSREP_SST_OPT_SST_VER=${remain%%/*}
+                readonly WSREP_SST_OPT_SST_VER="${remain%%/*}"
             else
                 readonly WSREP_SST_OPT_SST_VER=""
             fi
@@ -123,24 +131,23 @@ case "$1" in
         WSREP_SST_OPT_BYPASS=1
         ;;
     '--datadir')
-        # strip trailing '/'
+        # Let's remove the trailing slash:
         readonly WSREP_SST_OPT_DATA="${2%/}"
         shift
         ;;
     '--innodb-data-home-dir')
-        readonly INNODB_DATA_HOME_DIR_ARG="$2"
+        # Let's remove the trailing slash:
+        readonly INNODB_DATA_HOME_DIR="${2%/}"
         shift
         ;;
     '--innodb-log-group-home-dir')
-        readonly INNODB_LOG_GROUP_HOME_ARG="$2"
+        # Let's remove the trailing slash:
+        readonly INNODB_LOG_GROUP_HOME="${2%/}"
         shift
         ;;
     '--innodb-undo-directory')
-        readonly INNODB_UNDO_DIR_ARG="$2"
-        shift
-        ;;
-    '--log-bin')
-        readonly LOG_BIN_ARG="$2"
+        # Let's remove the trailing slash:
+        readonly INNODB_UNDO_DIR="${2%/}"
         shift
         ;;
     '--defaults-file')
@@ -157,7 +164,28 @@ case "$1" in
         shift
         ;;
     '--host')
-        readonly WSREP_SST_OPT_HOST="$2"
+        case "$2" in
+        \[*)
+            # IPv6
+            # Remove the starting and ending square brackets, if present:
+            addr_no_bracket="${2#\[}"
+            # Some utilities and subsequent code require an address
+            # without square brackets:
+            readonly WSREP_SST_OPT_HOST_UNESCAPED="${addr_no_bracket%%\]*}"
+            # Square brackets are needed in most cases:
+            readonly WSREP_SST_OPT_HOST="[${WSREP_SST_OPT_HOST_UNESCAPED}]"
+            readonly WSREP_SST_OPT_HOST_ESCAPED="\\[${WSREP_SST_OPT_HOST_UNESCAPED}\\]"
+            # Mark this address as IPv6:
+            readonly WSREP_SST_OPT_HOST_IPv6=1
+            ;;
+        *)
+            readonly WSREP_SST_OPT_HOST="$2"
+            readonly WSREP_SST_OPT_HOST_UNESCAPED="$2"
+            readonly WSREP_SST_OPT_HOST_ESCAPED="$2"
+            readonly WSREP_SST_OPT_HOST_IPv6=0
+            ;;
+        esac
+        WSREP_SST_OPT_ADDR="$WSREP_SST_OPT_HOST"
         shift
         ;;
     '--local-port')
@@ -192,14 +220,18 @@ case "$1" in
         readonly WSREP_SST_OPT_GTID="$2"
         shift
         ;;
-    '--binlog')
-        WSREP_SST_OPT_BINLOG="$2"
+    '--binlog'|'--log-bin')
+        readonly WSREP_SST_OPT_BINLOG="$2"
+        shift
+        ;;
+    '--binlog-index'|'--log-bin-index')
+        readonly WSREP_SST_OPT_BINLOG_INDEX="$2"
+        shift
+        ;;
+    '--log-basename')
+        readonly WSREP_SST_OPT_LOG_BASENAME="$2"
         shift
         ;;
-    '--binlog-index')
-	WSREP_SST_OPT_BINLOG_INDEX="$2"
-	shift
-	;;
     '--gtid-domain-id')
         readonly WSREP_SST_OPT_GTID_DOMAIN_ID="$2"
         shift
@@ -208,45 +240,114 @@ case "$1" in
         original_cmd=""
         shift
         while [ $# -gt 0 ]; do
-           option=${1%%=*}
-           if [[ "$option" != "--defaults-file" && \
-                 "$option" != "--defaults-extra-file" && \
-                 "$option" != "--defaults-group-suffix" && \
-                 "$option" != "--port" && \
-                 "$option" != "--socket" ]]; then
-              value=${1#*=}
-              if [ "$value" == "$1" ]; then
-                 value=""
-              fi
-              case "$option" in
-                  '--innodb-data-home-dir')
-                      if [ -z "$INNODB_DATA_HOME_DIR_ARG" ]; then
-                          readonly INNODB_DATA_HOME_DIR_ARG="$value"
-                      fi
-                      ;;
-                  '--innodb-log-group-home-dir')
-                      if [ -z "$INNODB_LOG_GROUP_HOME_ARG" ]; then
-                          readonly INNODB_LOG_GROUP_HOME_ARG="$value"
-                      fi
-                      ;;
-                  '--innodb-undo-directory')
-                      if [ -z "$INNODB_UNDO_DIR_ARG" ]; then
-                          readonly INNODB_UNDO_DIR_ARG="$value"
-                      fi
-                      ;;
-                  '--log-bin')
-                      if [ -z "$LOG_BIN_ARG" ]; then
-                          readonly LOG_BIN_ARG="$value"
-                      fi
-                      ;;
-              esac
-              if [ -z "$original_cmd" ]; then
-                  original_cmd="$1"
-              else
-                  original_cmd="$original_cmd $1"
-              fi
+           # check if the argument is the short option
+           # (starting with "-" instead of "--"):
+           if [ "${1#--}" = "$1" -a "${1#-}" != "$1" ]; then
+               option="${1#-}"
+               value=""
+               # check that the option value follows the name,
+               # without a space:
+               if [ ${#option} -gt 1 ]; then
+                   # let's separate the first character as the option name,
+                   # and the subsequent characters consider its value:
+                   value="${1#-?}"
+                   option="${1%$value}"
+               # check that the option name consists of one letter
+               # and there are the following arguments:
+               elif [ ${#option} -eq 1 -a $# -gt 1 ]; then
+                   # if the next argument does not start with a "-" character,
+                   # then this is the value of the current option:
+                   if [ "${2#-}" = "$2" ]; then
+                       value="$2"
+                       shift
+                   fi
+               fi
+               shift
+               if [ "$option" = 'h' ]; then
+                   if [ -z "$WSREP_SST_OPT_DATA" ]; then
+                       MYSQLD_OPT_DATADIR="${value%/}"
+                   fi
+               elif [ "$option" != 'u' -a \
+                      "$option" != 'P' ]; then
+                   if [ -z "$original_cmd" ]; then
+                       original_cmd="'-$option$value'"
+                   else
+                       original_cmd="$original_cmd '-$option$value'"
+                   fi
+               fi
+               continue;
            fi
-           shift
+           option="${1%%=*}"
+           if [ "$option" != '--defaults-file' -a \
+                "$option" != '--defaults-extra-file' -a \
+                "$option" != '--defaults-group-suffix' -a \
+                "$option" != '--user' -a \
+                "$option" != '--port' -a \
+                "$option" != '--socket' ]; then
+               value="${1#*=}"
+               if [ "$value" = "$1" ]; then
+                   value=""
+               fi
+               # Let's fill in the variables containing important paths
+               # that might not have been passed through explicit parameters
+               # (+ removing the trailing slash in these paths). Many of these
+               # options are processed internally within scripts or passed
+               # explicitly to other programs, so we need to remove them
+               # from mysqld's argument list:
+               skip_mysqld_arg=0
+               case "$option" in
+                   '--innodb-data-home-dir')
+                       if [ -z "$INNODB_DATA_HOME_DIR" ]; then
+                           MYSQLD_OPT_INNODB_DATA_HOME_DIR="${value%/}"
+                       fi
+                       skip_mysqld_arg=1
+                       ;;
+                   '--innodb-log-group-home-dir')
+                       if [ -z "$INNODB_LOG_GROUP_HOME" ]; then
+                           MYSQLD_OPT_INNODB_LOG_GROUP_HOME="${value%/}"
+                       fi
+                       skip_mysqld_arg=1
+                       ;;
+                   '--innodb-undo-directory')
+                       if [ -z "$INNODB_UNDO_DIR" ]; then
+                           MYSQLD_OPT_INNODB_UNDO_DIR="${value%/}"
+                       fi
+                       skip_mysqld_arg=1
+                       ;;
+                   '--log-bin')
+                       if [ -z "$WSREP_SST_OPT_BINLOG" ]; then
+                           MYSQLD_OPT_LOG_BIN="$value"
+                       fi
+                       skip_mysqld_arg=1
+                       ;;
+                   '--log-bin-index')
+                       if [ -z "$WSREP_SST_OPT_BINLOG_INDEX" ]; then
+                           MYSQLD_OPT_LOG_BIN_INDEX="$value"
+                       fi
+                       skip_mysqld_arg=1
+                       ;;
+                   '--log-basename')
+                       if [ -z "$WSREP_SST_OPT_LOG_BASENAME" ]; then
+                           MYSQLD_OPT_LOG_BASENAME="$value"
+                       fi
+                       skip_mysqld_arg=1
+                       ;;
+                   '--datadir')
+                       if [ -z "$WSREP_SST_OPT_DATA" ]; then
+                           MYSQLD_OPT_DATADIR="${value%/}"
+                       fi
+                       skip_mysqld_arg=1
+                       ;;
+               esac
+               if [ $skip_mysqld_arg -eq 0 ]; then
+                   if [ -z "$original_cmd" ]; then
+                       original_cmd="'$1'"
+                   else
+                       original_cmd="$original_cmd '$1'"
+                   fi
+               fi
+            fi
+            shift
         done
         readonly WSREP_SST_OPT_MYSQLD="$original_cmd"
         break
@@ -259,20 +360,169 @@ esac
 shift
 done
 readonly WSREP_SST_OPT_BYPASS
-readonly WSREP_SST_OPT_BINLOG
-readonly WSREP_SST_OPT_BINLOG_INDEX
-
-if [ -n "${WSREP_SST_OPT_ADDR_PORT:-}" ]; then
-  if [ -n "${WSREP_SST_OPT_PORT:-}" ]; then
-    if [ "$WSREP_SST_OPT_PORT" != "$WSREP_SST_OPT_ADDR_PORT" ]; then
-      echo "WSREP_SST: [ERROR] port in --port=$WSREP_SST_OPT_PORT differs from port in --address=$WSREP_SST_OPT_ADDR" >&2
-      exit 2
+
+# The same argument can be present on the command line several
+# times, in this case we must take its last value:
+if [ -n "${MYSQLD_OPT_INNODB_DATA_HOME_DIR:-}" -a \
+     -z "$INNODB_DATA_HOME_DIR" ]; then
+    readonly INNODB_DATA_HOME_DIR="$MYSQLD_OPT_INNODB_DATA_HOME_DIR"
+fi
+if [ -n "${MYSQLD_OPT_INNODB_LOG_GROUP_HOME:-}" -a \
+     -z "$INNODB_LOG_GROUP_HOME" ]; then
+    readonly INNODB_LOG_GROUP_HOME="$MYSQLD_OPT_INNODB_LOG_GROUP_HOME"
+fi
+if [ -n "${MYSQLD_OPT_INNODB_UNDO_DIR:-}" -a \
+     -z "$INNODB_UNDO_DIR" ]; then
+    readonly INNODB_UNDO_DIR="$MYSQLD_OPT_INNODB_UNDO_DIR"
+fi
+if [ -n "${MYSQLD_OPT_LOG_BIN:-}" -a \
+     -z "$WSREP_SST_OPT_BINLOG" ]; then
+    readonly WSREP_SST_OPT_BINLOG="$MYSQLD_OPT_LOG_BIN"
+fi
+if [ -n "${MYSQLD_OPT_LOG_BIN_INDEX:-}" -a \
+     -z "$WSREP_SST_OPT_BINLOG_INDEX" ]; then
+    readonly WSREP_SST_OPT_BINLOG_INDEX="$MYSQLD_OPT_LOG_BIN_INDEX"
+fi
+if [ -n "${MYSQLD_OPT_DATADIR:-}" -a \
+     -z "$WSREP_SST_OPT_DATA" ]; then
+    readonly WSREP_SST_OPT_DATA="$MYSQLD_OPT_DATADIR"
+fi
+if [ -n "${MYSQLD_OPT_LOG_BASENAME:-}" -a \
+     -z "$WSREP_SST_OPT_LOG_BASENAME" ]; then
+    readonly WSREP_SST_OPT_LOG_BASENAME="$MYSQLD_OPT_LOG_BASENAME"
+fi
+
+# If the --log-bin option is present without a value, then
+# setting WSREP_SST_OPT_BINLOG by using other arguments:
+if [ -z "$WSREP_SST_OPT_BINLOG" -a -n "${MYSQLD_OPT_LOG_BIN+x}" ]; then
+    if [ -n "$WSREP_SST_OPT_LOG_BASENAME" ]; then
+        # If the WSREP_SST_OPT_BINLOG variable is not set, but
+        # --log-basename is present among the arguments to mysqld,
+        # then set WSREP_SST_OPT_BINLOG equal to the base name with
+        # the "-bin" suffix:
+        readonly WSREP_SST_OPT_BINLOG="$WSREP_SST_OPT_LOG_BASENAME-bin"
+    else
+        # Take the default name:
+        readonly WSREP_SST_OPT_BINLOG='mysql-bin'
+    fi
+fi
+
+# Reconstructing the command line arguments that control the innodb
+# and binlog options:
+if [ -n "$WSREP_SST_OPT_LOG_BASENAME" ]; then
+    INNOEXTRA="$INNOEXTRA --log-basename='$WSREP_SST_OPT_LOG_BASENAME'"
+fi
+if [ -n "$INNODB_DATA_HOME_DIR" ]; then
+    INNOEXTRA="$INNOEXTRA --innodb-data-home-dir='$INNODB_DATA_HOME_DIR'"
+fi
+if [ -n "$INNODB_LOG_GROUP_HOME" ]; then
+    INNOEXTRA="$INNOEXTRA --innodb-log-group-home-dir='$INNODB_LOG_GROUP_HOME'"
+fi
+if [ -n "$INNODB_UNDO_DIR" ]; then
+    INNOEXTRA="$INNOEXTRA --innodb-undo-directory='$INNODB_UNDO_DIR'"
+fi
+if [ -n "$WSREP_SST_OPT_BINLOG" ]; then
+    INNOEXTRA="$INNOEXTRA --log-bin='$WSREP_SST_OPT_BINLOG'"
+    if [ -n "$WSREP_SST_OPT_BINLOG_INDEX" ]; then
+        INNOEXTRA="$INNOEXTRA --log-bin-index='$WSREP_SST_OPT_BINLOG_INDEX'"
+    fi
+fi
+
+get_binlog()
+{
+    # if no command line argument and WSREP_SST_OPT_BINLOG is not set,
+    # try to get it from my.cnf:
+    if [ -z "$WSREP_SST_OPT_BINLOG" ]; then
+        WSREP_SST_OPT_BINLOG=$(parse_cnf '--mysqld' 'log-bin')
+    fi
+    # if no command line argument and WSREP_SST_OPT_BINLOG_INDEX is not set,
+    # try to get it from my.cnf:
+    if [ -z "$WSREP_SST_OPT_BINLOG_INDEX" ]; then
+        WSREP_SST_OPT_BINLOG_INDEX=$(parse_cnf '--mysqld' 'log-bin-index')
+    fi
+    # if no command line argument and WSREP_SST_OPT_LOG_BASENAME is not set,
+    # try to get it from my.cnf:
+    if [ -z "$WSREP_SST_OPT_LOG_BASENAME" ]; then
+        WSREP_SST_OPT_LOG_BASENAME=$(parse_cnf '--mysqld' 'log-basename')
+    fi
+    if [ -z "$WSREP_SST_OPT_BINLOG" ]; then
+        # If the --log-bin option is specified without a parameter,
+        # then we need to build the name of the index file according
+        # to the rules described in the server documentation:
+        if [ -n "${MYSQLD_OPT_LOG_BIN+x}" -o \
+             $(in_config '--mysqld' 'log-bin') -eq 1 ]
+        then
+            if [ -n "$WSREP_SST_OPT_LOG_BASENAME" ]; then
+                # If the WSREP_SST_OPT_BINLOG variable is not set, but
+                # --log-basename is present among the arguments of mysqld,
+                # then set WSREP_SST_OPT_BINLOG equal to the base name with
+                # the "-bin" suffix:
+                readonly WSREP_SST_OPT_BINLOG="$WSREP_SST_OPT_LOG_BASENAME-bin"
+            else
+                # If the --log-bin option is present without a value, then
+                # we take the default name:
+                readonly WSREP_SST_OPT_BINLOG='mysql-bin'
+            fi
+        fi
+    fi
+    if [ -n "$WSREP_SST_OPT_BINLOG" ]; then
+        # If the name of the index file is not specified, then we will build
+        # it according to the specifications for the server:
+        if [ -z "$WSREP_SST_OPT_BINLOG_INDEX" ]; then
+            if [ -n "$WSREP_SST_OPT_LOG_BASENAME" ]; then
+                # If the WSREP_SST_OPT_BINLOG variable is not set, but
+                # --log-basename is present among the arguments of mysqld,
+                # then set WSREP_SST_OPT_BINLOG equal to the base name with
+                # the "-bin" suffix:
+                readonly WSREP_SST_OPT_BINLOG_INDEX="$WSREP_SST_OPT_LOG_BASENAME-bin.index"
+            else
+                # If the base name not specified, then we take
+                # the default name:
+                readonly WSREP_SST_OPT_BINLOG_INDEX='mysql-bin.index'
+            fi
+        fi
+    fi
+}
+
+# Check the presence of the port value and, if necessary, transfer
+# the port number from the address to the WSREP_SST_OPT_PORT variable
+# or vice versa, and also, if necessary, substitute the missing port
+# value into the address value:
+if [ -n "$WSREP_SST_OPT_ADDR_PORT" ]; then
+    if [ -n "$WSREP_SST_OPT_PORT" ]; then
+        if [ "$WSREP_SST_OPT_PORT" != "$WSREP_SST_OPT_ADDR_PORT" ]; then
+            echo "WSREP_SST: [ERROR] port in --port=$WSREP_SST_OPT_PORT differs from port in --address=$WSREP_SST_OPT_ADDR" >&2
+            exit 2
+        fi
+    else
+        # If the address contains a port number, assign it to
+        # the corresponding variable:
+        readonly WSREP_SST_OPT_PORT="$WSREP_SST_OPT_ADDR_PORT"
+    fi
+elif [ -n "$WSREP_SST_OPT_ADDR" ]; then
+    # If the port is missing, take the default port:
+    if [ -z "$WSREP_SST_OPT_PORT" ]; then
+        readonly WSREP_SST_OPT_PORT=4444
+    fi
+    WSREP_SST_OPT_ADDR_PORT="$WSREP_SST_OPT_PORT"
+    # Let's remove the leading part that contains the host address:
+    remain="${WSREP_SST_OPT_ADDR#$WSREP_SST_OPT_HOST_ESCAPED}"
+    # Let's remove the ":" character that separates the port number
+    # from the hostname:
+    remain="${remain#:}"
+    # Let's remove all characters upto first "/" character that
+    # separates the hostname with port number from the path:
+    remain="${remain#/}"
+    # Let's construct a new value for the address with the port:
+    WSREP_SST_OPT_ADDR="$WSREP_SST_OPT_HOST:$WSREP_SST_OPT_PORT"
+    if [ -n "$remain" ]; then
+        WSREP_SST_OPT_ADDR="$WSREP_SST_OPT_ADDR/$remain"
     fi
-  else
-    readonly WSREP_SST_OPT_PORT="$WSREP_SST_OPT_ADDR_PORT"
-  fi
 fi
 
+readonly WSREP_SST_OPT_ADDR
+readonly WSREP_SST_OPT_ADDR_PORT
+
 # try to use my_print_defaults, mysql and mysqldump that come with the sources
 # (for MTR suite)
 SCRIPTS_DIR="$(cd $(dirname "$0"); pwd -P)"
@@ -282,13 +532,13 @@ CLIENT_DIR="$SCRIPTS_DIR/../client"
 if [ -x "$CLIENT_DIR/mysql" ]; then
     MYSQL_CLIENT="$CLIENT_DIR/mysql"
 else
-    MYSQL_CLIENT=mysql
+    MYSQL_CLIENT="$(command -v mysql)"
 fi
 
 if [ -x "$CLIENT_DIR/mysqldump" ]; then
     MYSQLDUMP="$CLIENT_DIR/mysqldump"
 else
-    MYSQLDUMP=mysqldump
+    MYSQLDUMP="$(command -v mysqldump)"
 fi
 
 if [ -x "$SCRIPTS_DIR/my_print_defaults" ]; then
@@ -296,53 +546,147 @@ if [ -x "$SCRIPTS_DIR/my_print_defaults" ]; then
 elif [ -x "$EXTRA_DIR/my_print_defaults" ]; then
     MY_PRINT_DEFAULTS="$EXTRA_DIR/my_print_defaults"
 else
-    MY_PRINT_DEFAULTS=my_print_defaults
+    MY_PRINT_DEFAULTS="$(command -v my_print_defaults)"
 fi
 
 wsrep_defaults="$WSREP_SST_OPT_DEFAULT"
 if [ -n "$wsrep_defaults" ]; then
-   wsrep_defaults="$wsrep_defaults "
+    wsrep_defaults="$wsrep_defaults "
 fi
 wsrep_defaults="$wsrep_defaults$WSREP_SST_OPT_EXTRA_DEFAULT"
 if [ -n "$wsrep_defaults" ]; then
-   wsrep_defaults="$wsrep_defaults "
+    wsrep_defaults="$wsrep_defaults "
 fi
 readonly WSREP_SST_OPT_CONF="$wsrep_defaults$WSREP_SST_OPT_SUFFIX_DEFAULT"
 readonly MY_PRINT_DEFAULTS="$MY_PRINT_DEFAULTS $WSREP_SST_OPT_CONF"
 
-wsrep_auth_not_set()
+#
+# User can specify mariabackup specific settings that will be used during sst
+# process like encryption, etc. Parse such configuration option.
+#
+# 1st parameter: group (config file section like sst) or
+#                my_print_defaults argument (like --mysqld)
+# 2nd parameter: var : name of the variable in the section, e.g. server-id
+# 3rd parameter: default value for the parameter
+#
+parse_cnf()
 {
-    [ -z "$WSREP_SST_OPT_AUTH" -o "$WSREP_SST_OPT_AUTH" = "(null)" ]
+    local group="$1"
+    local var="$2"
+    local reval=""
+
+    # normalize the variable names specified in cnf file (user can use _ or - for example log-bin or log_bin)
+    # then search for needed variable
+    # finally get the variable value (if variables has been specified multiple time use the last value only)
+
+    if [ "$group" = '--mysqld' -o \
+         "$group" = 'mysqld' ]; then
+       if [ -n "$WSREP_SST_OPT_SUFFIX_VALUE" ]; then
+           reval=$($MY_PRINT_DEFAULTS "mysqld$WSREP_SST_OPT_SUFFIX_VALUE" | awk 'BEGIN {OFS=FS="="} {sub(/^--loose/,"-",$0); gsub(/_/,"-",$1); if ($1=="--'"$var"'") lastval=substr($0,length($1)+2)} END {print lastval}')
+       fi
+    fi
+
+    if [ -z "$reval" ]; then
+        reval=$($MY_PRINT_DEFAULTS "$group" | awk 'BEGIN {OFS=FS="="} {sub(/^--loose/,"-",$0); gsub(/_/,"-",$1); if ($1=="--'"$var"'") lastval=substr($0,length($1)+2)} END {print lastval}')
+    fi
+
+    # use default if we haven't found a value
+    if [ -z "$reval" ]; then
+        [ -n "${3:-}" ] && reval="$3"
+    fi
+    echo $reval
 }
 
-# State Snapshot Transfer authentication password was displayed in the ps output. Bug fixed #1200727.
-if $MY_PRINT_DEFAULTS sst | grep -q "wsrep_sst_auth"; then
-    if wsrep_auth_not_set; then
-            WSREP_SST_OPT_AUTH=$($MY_PRINT_DEFAULTS sst | grep -- "--wsrep_sst_auth" | cut -d= -f2)
+#
+# This function simply checks for the presence of the parameter
+# in the config file, but does not return its value. It returns "1"
+# (true) even if the parameter is present in the configuration file
+# without a value:
+#
+in_config()
+{
+    local group="$1"
+    local var="$2"
+    local found=0
+    if [ "$group" = '--mysqld' -o \
+         "$group" = 'mysqld' ]; then
+       if [ -n "$WSREP_SST_OPT_SUFFIX_VALUE" ]; then
+           found=$($MY_PRINT_DEFAULTS "mysqld$WSREP_SST_OPT_SUFFIX_VALUE" | awk 'BEGIN {OFS=FS="="; found=0} {sub(/^--loose/,"-",$0); gsub(/_/,"-",$1); if ($1=="--'"$var"'") found=1} END {print found}')
+       fi
+    fi
+    if [ $found -eq 0 ]; then
+        found=$($MY_PRINT_DEFAULTS "$group" | awk 'BEGIN {OFS=FS="="; found=0} {sub(/^--loose/,"-",$0); gsub(/_/,"-",$1); if ($1=="--'"$var"'") found=1} END {print found}')
     fi
+    echo $found
+}
+
+wsrep_auth_not_set()
+{
+    [ -z "$WSREP_SST_OPT_AUTH" ]
+}
+
+# Get rid of incorrect values resulting from substitution
+# in programs external to the script:
+if [ "$WSREP_SST_OPT_USER" = '(null)' ]; then
+    WSREP_SST_OPT_USER=""
+fi
+if [ "$WSREP_SST_OPT_PSWD" = '(null)' ]; then
+    WSREP_SST_OPT_PSWD=""
+fi
+if [ "$WSREP_SST_OPT_AUTH" = '(null)' ]; then
+    WSREP_SST_OPT_AUTH=""
+fi
+
+# Let's read the value of the authentication string from the
+# configuration file so that it does not go to the command line
+# and does not appear in the ps output:
+if wsrep_auth_not_set; then
+    WSREP_SST_OPT_AUTH=$(parse_cnf 'sst' 'wsrep-sst-auth')
 fi
-readonly WSREP_SST_OPT_AUTH
 
-# Splitting AUTH into potential user:password pair
+# Splitting WSREP_SST_OPT_AUTH as "user:password" pair:
 if ! wsrep_auth_not_set
 then
-    WSREP_SST_OPT_USER="${WSREP_SST_OPT_AUTH%:*}"
-    WSREP_SST_OPT_PSWD="${WSREP_SST_OPT_AUTH##*:}"
+    # Extract username as shortest prefix up to first ':' character:
+    WSREP_SST_OPT_AUTH_USER="${WSREP_SST_OPT_AUTH%%:*}"
+    if [ -z "$WSREP_SST_OPT_USER" ]; then
+        # if the username is not in the command line arguments,
+        # set the username and password using WSREP_SST_OPT_AUTH
+        # from the environment:
+        WSREP_SST_OPT_USER="$WSREP_SST_OPT_AUTH_USER"
+        WSREP_SST_OPT_PSWD="${WSREP_SST_OPT_AUTH#*:}"
+    elif [ "$WSREP_SST_OPT_USER" = "$WSREP_SST_OPT_AUTH_USER" ]; then
+        # If the username in the command line arguments and in
+        # the environment variable are the same, set the password
+        # if it was not specified in the command line:
+        if [ -z "$WSREP_SST_OPT_PSWD" ]; then
+            WSREP_SST_OPT_PSWD="${WSREP_SST_OPT_AUTH#*:}"
+        fi
+    else
+        # The username is passed through the command line and does
+        # not match the username in the environment variable - ignore
+        # the environment and rebuild the authentication parameters:
+        WSREP_SST_OPT_AUTH="$WSREP_SST_OPT_USER:$WSREP_SST_OPT_PSWD"
+    fi
 fi
+
 readonly WSREP_SST_OPT_USER
 readonly WSREP_SST_OPT_PSWD
+readonly WSREP_SST_OPT_AUTH
 
 if [ -n "$WSREP_SST_OPT_REMOTE_AUTH" ]
 then
     # Split auth string at the last ':'
-    readonly WSREP_SST_OPT_REMOTE_USER="${WSREP_SST_OPT_REMOTE_AUTH%:*}"
-    readonly WSREP_SST_OPT_REMOTE_PSWD="${WSREP_SST_OPT_REMOTE_AUTH##*:}"
+    readonly WSREP_SST_OPT_REMOTE_USER="${WSREP_SST_OPT_REMOTE_AUTH%%:*}"
+    readonly WSREP_SST_OPT_REMOTE_PSWD="${WSREP_SST_OPT_REMOTE_AUTH#*:}"
 else
     readonly WSREP_SST_OPT_REMOTE_USER=
     readonly WSREP_SST_OPT_REMOTE_PSWD=
 fi
 
-if [ -n "${WSREP_SST_OPT_DATA:-}" ]
+readonly WSREP_SST_OPT_REMOTE_AUTH
+
+if [ -n "$WSREP_SST_OPT_DATA" ]
 then
     SST_PROGRESS_FILE="$WSREP_SST_OPT_DATA/sst_in_progress"
 else
@@ -374,17 +718,16 @@ wsrep_log_info()
 
 wsrep_cleanup_progress_file()
 {
-    [ -n "${SST_PROGRESS_FILE:-}" ] && rm -f "$SST_PROGRESS_FILE" 2>/dev/null || true
+    [ -n "$SST_PROGRESS_FILE" ] && rm -f "$SST_PROGRESS_FILE" 2>/dev/null || true
 }
 
 wsrep_check_program()
 {
-    local prog=$1
-
-    if ! command -v $prog >/dev/null
-    then
+    local prog="$1"
+    local cmd=$(command -v "$prog")
+    if [ ! -x "$cmd" ]; then
         echo "'$prog' not found in PATH"
-        exit 2 # ENOENT no such file or directory
+        return 2 # no such file or directory
     fi
 }
 
@@ -394,55 +737,49 @@ wsrep_check_programs()
 
     while [ $# -gt 0 ]
     do
-        wsrep_check_program $1
+        wsrep_check_program $1 || ret=$?
         shift
     done
+
+    return $ret
+}
+
+wsrep_check_datadir()
+{
+    if [ -z "$WSREP_SST_OPT_DATA" ]
+    then
+        wsrep_log_error "The '--datadir' parameter must be passed to the SST script"
+        exit 2
+    fi
+}
+
+get_openssl()
+{
+    # If the OPENSSL_BINARY variable is already defined, just return:
+    if [ -n "${OPENSSL_BINARY+x}" ]; then
+        return
+    fi
+    # Let's look for openssl:
+    OPENSSL_BINARY="$(command -v openssl)"
+    if [ ! -x "$OPENSSL_BINARY" ]; then
+        OPENSSL_BINARY='/usr/bin/openssl'
+        if [ ! -x "$OPENSSL_BINARY" ]; then
+            OPENSSL_BINARY=""
+        fi
+    fi
+    readonly OPENSSL_BINARY
 }
 
 # Generate a string equivalent to 16 random bytes
 wsrep_gen_secret()
 {
-    if [ -x /usr/bin/openssl ]
+    get_openssl
+    if [ -n "$OPENSSL_BINARY" ]
     then
-        echo `/usr/bin/openssl rand -hex 16`
+        echo $("$OPENSSL_BINARY" rand -hex 16)
     else
         printf "%04x%04x%04x%04x%04x%04x%04x%04x" \
                 $RANDOM $RANDOM $RANDOM $RANDOM   \
                 $RANDOM $RANDOM $RANDOM $RANDOM
     fi
 }
-
-#
-# user can specify mariabackup specific settings that will be used during sst
-# process like encryption, etc.....
-# parse such configuration option. (group for xb settings is [sst] in my.cnf
-#
-# 1st param: group (config file section like sst) or my_print_defaults argument (like --mysqld)
-# 2nd param: var : name of the variable in the section, e.g. server-id
-# 3rd param: - : default value for the param
-parse_cnf()
-{
-    local group=$1
-    local var=${2//_/-} # normalize variable name by replacing all '_' with '-'
-    local reval=""
-
-    # first normalize output variable names specified in cnf file:
-    # user can use _ or - (for example log-bin or log_bin) and/or prefix
-    # variable with --loose-
-    # then search for needed variable
-    # finally get the variable value (if variables has been specified multiple time use the last value only)
-
-    reval=$($MY_PRINT_DEFAULTS "${group}" | \
-            awk -v var="${var}" 'BEGIN { OFS=FS="=" } \
-                                       { sub(/^--loose/,"-",$0); \
-                                         gsub(/_/,"-",$1); \
-                                         if ( $1=="--"var) \
-                                             lastval=substr($0,length($1)+2) } \
-                                 END { print lastval}')
-
-    # use default if we haven't found a value
-    if [ -z "$reval" ]; then
-        [ -n "$3" ] && reval=$3
-    fi
-    echo $reval
-}
diff --git a/scripts/wsrep_sst_mariabackup.sh b/scripts/wsrep_sst_mariabackup.sh
index f50618f6ef1..8b05217b2fa 100644
--- a/scripts/wsrep_sst_mariabackup.sh
+++ b/scripts/wsrep_sst_mariabackup.sh
@@ -21,6 +21,7 @@
 # Make sure to read that before proceeding!
 
 . $(dirname $0)/wsrep_sst_common
+wsrep_check_datadir
 
 OS=$(uname)
 ealgo=""
@@ -85,34 +86,33 @@ pcmd="pv $pvopts"
 declare -a RC
 
 set +e
-INNOBACKUPEX_BIN=$(which mariabackup)
-if test -z $INNOBACKUPEX_BIN
-then
-  wsrep_log_error 'mariabackup binary not found in $PATH'
-  exit 42
+MARIABACKUP_BIN="$(command -v mariabackup)"
+if [ -z "$MARIABACKUP_BIN" ]; then
+    wsrep_log_error 'mariabackup binary not found in $PATH'
+    exit 42
 fi
 set -e
-XBSTREAM_BIN=mbstream
+MBSTREAM_BIN=mbstream
 XBCRYPT_BIN=xbcrypt # Not available in MariaBackup
 
 DATA="${WSREP_SST_OPT_DATA}"
 INFO_FILE="xtrabackup_galera_info"
 IST_FILE="xtrabackup_ist"
-MAGIC_FILE="${DATA}/${INFO_FILE}"
-INNOAPPLYLOG="${DATA}/mariabackup.prepare.log"
-INNOMOVELOG="${DATA}/mariabackup.move.log"
-INNOBACKUPLOG="${DATA}/mariabackup.backup.log"
+MAGIC_FILE="$DATA/$INFO_FILE"
+INNOAPPLYLOG="$DATA/mariabackup.prepare.log"
+INNOMOVELOG="$DATA/mariabackup.move.log"
+INNOBACKUPLOG="$DATA/mariabackup.backup.log"
 
 # Setting the path for ss and ip
 export PATH="/usr/sbin:/sbin:$PATH"
 
 timeit(){
-    local stage=$1
+    local stage="$1"
     shift
     local cmd="$@"
     local x1 x2 took extcode
 
-    if [[ $ttime -eq 1 ]];then 
+    if [[ $ttime -eq 1 ]];then
         x1=$(date +%s)
         wsrep_log_info "Evaluating $cmd"
         eval "$cmd"
@@ -121,7 +121,7 @@ timeit(){
         took=$(( x2-x1 ))
         wsrep_log_info "NOTE: $stage took $took seconds"
         totime=$(( totime+took ))
-    else 
+    else
         wsrep_log_info "Evaluating $cmd"
         eval "$cmd"
         extcode=$?
@@ -132,18 +132,18 @@ timeit(){
 get_keys()
 {
     # $encrypt -eq 1 is for internal purposes only
-    if [[ $encrypt -ge 2 || $encrypt -eq -1 ]];then 
-        return 
+    if [ $encrypt -ge 2 -o $encrypt -eq -1 ]; then
+        return
     fi
 
-    if [[ $encrypt -eq 0 ]];then 
-        if $MY_PRINT_DEFAULTS xtrabackup | grep -q encrypt;then
+    if [ $encrypt -eq 0 ]; then
+        if $MY_PRINT_DEFAULTS xtrabackup | grep -q -- "--encrypt"; then
             wsrep_log_error "Unexpected option combination. SST may fail. Refer to http://www.percona.com/doc/percona-xtradb-cluster/manual/xtrabackup_sst.html"
         fi
         return
     fi
 
-    if [[ $sfmt == 'tar' ]];then
+    if [ $sfmt = 'tar' ]; then
         wsrep_log_info "NOTE: Xtrabackup-based encryption - encrypt=1 - cannot be enabled with tar format"
         encrypt=-1
         return
@@ -151,24 +151,24 @@ get_keys()
 
     wsrep_log_info "Xtrabackup based encryption enabled in my.cnf - Supported only from Xtrabackup 2.1.4"
 
-    if [[ -z $ealgo ]];then
+    if [ -z "$ealgo" ]; then
         wsrep_log_error "FATAL: Encryption algorithm empty from my.cnf, bailing out"
         exit 3
     fi
 
-    if [[ -z $ekey && ! -r $ekeyfile ]];then
+    if [ -z "$ekey" -a ! -r "$ekeyfile" ]; then
         wsrep_log_error "FATAL: Either key or keyfile must be readable"
         exit 3
     fi
 
-    if [[ -z $ekey ]];then
-        ecmd="${XBCRYPT_BIN} --encrypt-algo=$ealgo --encrypt-key-file=$ekeyfile"
+    if [ -z "$ekey" ]; then
+        ecmd="$XBCRYPT_BIN --encrypt-algo='$ealgo' --encrypt-key-file='$ekeyfile'"
     else
-        ecmd="${XBCRYPT_BIN} --encrypt-algo=$ealgo --encrypt-key=$ekey"
+        ecmd="$XBCRYPT_BIN --encrypt-algo='$ealgo' --encrypt-key='$ekey'"
     fi
 
-    if [[ "$WSREP_SST_OPT_ROLE" == "joiner" ]];then
-        ecmd+=" -d"
+    if [ "$WSREP_SST_OPT_ROLE" = 'joiner' ]; then
+        ecmd="$ecmd -d"
     fi
 
     stagemsg+="-XB-Encrypted"
@@ -176,32 +176,29 @@ get_keys()
 
 get_transfer()
 {
-    if [[ -z $SST_PORT ]];then 
-        TSST_PORT=4444
-    else 
-        TSST_PORT=$SST_PORT
-    fi
+    TSST_PORT="$SST_PORT"
 
-    if [[ $tfmt == 'nc' ]];then
+    if [ $tfmt = 'nc' ]; then
         wsrep_check_programs nc
         wsrep_log_info "Using netcat as streamer"
-        if [[ "$WSREP_SST_OPT_ROLE"  == "joiner" ]];then
-            if nc -h 2>&1 | grep -q ncat;then 
+
+        if [ "$WSREP_SST_OPT_ROLE" = 'joiner' ]; then
+            if nc -h 2>&1 | grep -q ncat; then
                 # Ncat
-                tcmd="nc -l ${TSST_PORT}"
-            elif nc -h 2>&1 | grep -qw -- '-d\>';then
+                tcmd="nc -l $TSST_PORT"
+            elif nc -h 2>&1 | grep -qw -- '-d\>'; then
                 # Debian netcat
-                if [ $WSREP_SST_OPT_HOST_IPv6 -eq 1 ];then
+                if [ $WSREP_SST_OPT_HOST_IPv6 -eq 1 ]; then
                     # When host is not explicitly specified (when only the port
                     # is specified) netcat can only bind to an IPv4 address if
                     # the "-6" option is not explicitly specified:
-                    tcmd="nc -dl -6 ${TSST_PORT}"
+                    tcmd="nc -dl -6 $TSST_PORT"
                 else
-                    tcmd="nc -dl ${TSST_PORT}"
+                    tcmd="nc -dl $TSST_PORT"
                 fi
             else
                 # traditional netcat
-                tcmd="nc -l -p ${TSST_PORT}"
+                tcmd="nc -l -p $TSST_PORT"
             fi
         else
             # Check to see if netcat supports the '-N' flag.
@@ -214,23 +211,22 @@ get_transfer()
             #
             tcmd_extra=""
             if nc -h 2>&1 | grep -qw -- -N; then
-                tcmd_extra+="-N"
-		wsrep_log_info "Using nc -N"
+                tcmd_extra="-N"
+                wsrep_log_info "Using nc -N"
             fi
-
             # netcat doesn't understand [] around IPv6 address
-            if nc -h 2>&1 | grep -q ncat;then
+            if nc -h 2>&1 | grep -q ncat; then
                 # Ncat
                 wsrep_log_info "Using Ncat as streamer"
-                tcmd="nc ${tcmd_extra} ${WSREP_SST_OPT_HOST_UNESCAPED} ${TSST_PORT}"
-            elif nc -h 2>&1 | grep -qw -- '-d\>';then
+                tcmd="nc $tcmd_extra $WSREP_SST_OPT_HOST_UNESCAPED $TSST_PORT"
+            elif nc -h 2>&1 | grep -qw -- '-d\>'; then
                 # Debian netcat
                 wsrep_log_info "Using Debian netcat as streamer"
-                tcmd="nc ${tcmd_extra} ${WSREP_SST_OPT_HOST_UNESCAPED} ${TSST_PORT}"
+                tcmd="nc $tcmd_extra $WSREP_SST_OPT_HOST_UNESCAPED $TSST_PORT"
             else
                 # traditional netcat
                 wsrep_log_info "Using traditional netcat as streamer"
-                tcmd="nc -q0 ${tcmd_extra} ${WSREP_SST_OPT_HOST_UNESCAPED} ${TSST_PORT}"
+                tcmd="nc -q0 $tcmd_extra $WSREP_SST_OPT_HOST_UNESCAPED $TSST_PORT"
             fi
         fi
     else
@@ -243,88 +239,65 @@ get_transfer()
             exit 2
         fi
 
-        if [[ $encrypt -eq 2 ]];then 
+        if [ $encrypt -eq 2 ]; then
             wsrep_log_info "Using openssl based encryption with socat: with crt and pem"
-            if [[ -z $tpem || -z $tcert ]];then 
+            if [ -z "$tpem" -o -z "$tcert" ]; then
                 wsrep_log_error "Both PEM and CRT files required"
                 exit 22
             fi
             stagemsg+="-OpenSSL-Encrypted-2"
-            if [[ "$WSREP_SST_OPT_ROLE"  == "joiner" ]];then
+            if [ "$WSREP_SST_OPT_ROLE" = 'joiner' ]; then
                 wsrep_log_info "Decrypting with cert=${tpem}, cafile=${tcert}"
-                tcmd="socat -u openssl-listen:${TSST_PORT},reuseaddr,cert=${tpem},cafile=${tcert}${sockopt} stdio"
+                tcmd="socat -u openssl-listen:$TSST_PORT,reuseaddr,cert='$tpem',cafile='$tcert'$sockopt stdio"
             else
                 wsrep_log_info "Encrypting with cert=${tpem}, cafile=${tcert}"
-                tcmd="socat -u stdio openssl-connect:${REMOTEIP}:${TSST_PORT},cert=${tpem},cafile=${tcert}${sockopt}"
+                tcmd="socat -u stdio openssl-connect:$REMOTEIP:$TSST_PORT,cert='$tpem',cafile='$tcert'$sockopt"
             fi
-        elif [[ $encrypt -eq 3 ]];then
+        elif [ $encrypt -eq 3 ]; then
             wsrep_log_info "Using openssl based encryption with socat: with key and crt"
-            if [[ -z $tpem || -z $tkey ]];then
+            if [ -z "$tpem" -o -z "$tkey" ]; then
                 wsrep_log_error "Both certificate and key files required"
                 exit 22
             fi
             stagemsg+="-OpenSSL-Encrypted-3"
-            if [[ -z $tcert ]];then
+            if [ -z "$tcert" ]; then
                 # no verification
-                if [[ "$WSREP_SST_OPT_ROLE"  == "joiner" ]];then
+                if [ "$WSREP_SST_OPT_ROLE" = 'joiner' ]; then
                     wsrep_log_info "Decrypting with cert=${tpem}, key=${tkey}, verify=0"
-                    tcmd="socat -u openssl-listen:${TSST_PORT},reuseaddr,cert=${tpem},key=${tkey},verify=0${sockopt} stdio"
+                    tcmd="socat -u openssl-listen:$TSST_PORT,reuseaddr,cert='$tpem',key='$tkey',verify=0$sockopt stdio"
                 else
                     wsrep_log_info "Encrypting with cert=${tpem}, key=${tkey}, verify=0"
-                    tcmd="socat -u stdio openssl-connect:${REMOTEIP}:${TSST_PORT},cert=${tpem},key=${tkey},verify=0${sockopt}"
+                    tcmd="socat -u stdio openssl-connect:$REMOTEIP:$TSST_PORT,cert='$tpem',key='$tkey',verify=0$sockopt"
                 fi
             else
                 # CA verification
-                if [[ "$WSREP_SST_OPT_ROLE"  == "joiner" ]];then
+                if [ "$WSREP_SST_OPT_ROLE" = 'joiner' ]; then
                     wsrep_log_info "Decrypting with cert=${tpem}, key=${tkey}, cafile=${tcert}"
-                    tcmd="socat -u openssl-listen:${TSST_PORT},reuseaddr,cert=${tpem},key=${tkey},cafile=${tcert}${sockopt} stdio"
+                    tcmd="socat -u openssl-listen:$TSST_PORT,reuseaddr,cert='$tpem',key='$tkey',cafile='$tcert'$sockopt stdio"
                 else
+                    CN_option=""
                     if [ -n "$WSREP_SST_OPT_REMOTE_USER" ]; then
-                        CN_option=",commonname=$WSREP_SST_OPT_REMOTE_USER"
-                    else
-                        CN_option=""
+                        CN_option=",commonname='$WSREP_SST_OPT_REMOTE_USER'"
                     fi
                     wsrep_log_info "Encrypting with cert=${tpem}, key=${tkey}, cafile=${tcert}"
-                    tcmd="socat -u stdio openssl-connect:${REMOTEIP}:${TSST_PORT},cert=${tpem},key=${tkey},cafile=${tcert}${CN_option}${sockopt}"
+                    tcmd="socat -u stdio openssl-connect:$REMOTEIP:$TSST_PORT,cert='$tpem',key='$tkey',cafile='$tcert'$CN_option$sockopt"
                 fi
             fi
-        else 
-            if [[ "$WSREP_SST_OPT_ROLE"  == "joiner" ]];then
-                tcmd="socat -u TCP-LISTEN:${TSST_PORT},reuseaddr${sockopt} stdio"
+        else
+            if [ "$WSREP_SST_OPT_ROLE" = 'joiner' ]; then
+                tcmd="socat -u TCP-LISTEN:$TSST_PORT,reuseaddr$sockopt stdio"
             else
-                tcmd="socat -u stdio TCP:${REMOTEIP}:${TSST_PORT}${sockopt}"
+                tcmd="socat -u stdio TCP:$REMOTEIP:$TSST_PORT$sockopt"
             fi
         fi
     fi
 }
 
-parse_cnf()
-{
-    local group=$1
-    local var=$2
-    # print the default settings for given group using my_print_default.
-    # remove possible 'loose' variable name prefix
-    # normalize the variable names specified in cnf file (user can use _ or - for example log-bin or log_bin)
-    # then grep for needed variable
-    # finally get the variable value (if variables has been specified multiple time use the last value only)
-    reval=$($MY_PRINT_DEFAULTS $group | \
-            awk -F= '{ sub(/^--loose/,"-",$0); \
-                       if ($1 ~ /_/) \
-                           { gsub(/_/,"-",$1); print $1"="$2 } \
-                       else \
-                           { print $0 }}' | \
-            grep -- "--$var=" | cut -d= -f2- | tail -1)
-    if [[ -z $reval ]];then 
-        [[ -n $3 ]] && reval=$3
-    fi
-    echo $reval
-}
-
 get_footprint()
 {
-    pushd $WSREP_SST_OPT_DATA 1>/dev/null
+    pushd "$WSREP_SST_OPT_DATA" 1>/dev/null
     payload=$(find . -regex '.*\.ibd$\|.*\.MYI$\|.*\.MYD$\|.*ibdata1$' -type f -print0 | du --files0-from=- --block-size=1 -c | awk 'END { print $1 }')
-    if $MY_PRINT_DEFAULTS xtrabackup | grep -q -- "--compress";then 
+    if $MY_PRINT_DEFAULTS xtrabackup | grep -q -- "--compress";then
         # QuickLZ has around 50% compression ratio
         # When compression/compaction used, the progress is only an approximate.
         payload=$(( payload*1/2 ))
@@ -336,8 +309,7 @@ get_footprint()
 
 adjust_progress()
 {
-
-    if ! command -v pv >/dev/null;then
+    if [ ! -x "$(command -v pv)" ]; then
         wsrep_log_error "pv not found in path: $PATH"
         wsrep_log_error "Disabling all progress/rate-limiting"
         pcmd=""
@@ -346,18 +318,18 @@ adjust_progress()
         return
     fi
 
-    if [[ -n $progress && $progress != '1' ]];then 
-        if [[ -e $progress ]];then 
-            pcmd+=" 2>>$progress"
-        else 
-            pcmd+=" 2>$progress"
+    if [ -n "$progress" -a "$progress" != '1' ]; then
+        if [ -e "$progress" ]; then
+            pcmd+=" 2>>'$progress'"
+        else
+            pcmd+=" 2>'$progress'"
         fi
-    elif [[ -z $progress && -n $rlimit  ]];then 
+    elif [ -z "$progress" -a -n "$rlimit" ]; then
             # When rlimit is non-zero
             pcmd="pv -q"
-    fi 
+    fi
 
-    if [[ -n $rlimit && "$WSREP_SST_OPT_ROLE"  == "donor" ]];then
+    if [ -n "$rlimit" -a "$WSREP_SST_OPT_ROLE" = 'donor' ]; then
         wsrep_log_info "Rate-limiting SST to $rlimit"
         pcmd+=" -L \$rlimit"
     fi
@@ -365,47 +337,64 @@ adjust_progress()
 
 check_server_ssl_config()
 {
-    local section=$1
-    tcert=$(parse_cnf $section ssl-ca "")
-    tpem=$(parse_cnf $section ssl-cert "")
-    tkey=$(parse_cnf $section ssl-key "")
-    if [ 0 -eq $encrypt -a -n "$tpem" -a -n "$tkey" ]
-    then
-         encrypt=3 # enable cert/key SSL encyption
-
-         # avoid CA verification if not set explicitly:
-         # nodes may happen to have different CA if self-generated
-         # zeroing up tcert does the trick
-         local mode=$(parse_cnf SST ssl-mode "")
-         [[ ${mode} = *VERIFY* ]] || tcert=""
-    fi
+    local section="$1"
+    tcert=$(parse_cnf "$section" 'ssl-ca')
+    tpem=$(parse_cnf "$section" 'ssl-cert')
+    tkey=$(parse_cnf "$section" 'ssl-key')
 }
 
 read_cnf()
 {
-    sfmt=$(parse_cnf sst streamfmt "xbstream")
+    sfmt=$(parse_cnf sst streamfmt "mbstream")
     tfmt=$(parse_cnf sst transferfmt "socat")
-    tcert=$(parse_cnf sst tca "")
-    tpem=$(parse_cnf sst tcert "")
-    tkey=$(parse_cnf sst tkey "")
-    encrypt=$(parse_cnf sst encrypt 0)
-    tmode=$(parse_cnf sst ssl-mode "DISABLED" | tr [:lower:] [:upper:])
-
-    if [ -z "$tpem" -a -z "$tkey" -a -z "$tcert" ]
-    then # no old-style SSL config in [sst]
-        if [ "$tmode" != "DISABLED" ]
+
+    encrypt=$(parse_cnf 'sst' 'encrypt' 0)
+    tmode=$(parse_cnf 'sst' 'ssl-mode' 'DISABLED' | tr [:lower:] [:upper:])
+
+    if [ $encrypt -eq 0 -o $encrypt -ge 2 ]
+    then
+        if [ "$tmode" != 'DISABLED' -o $encrypt -ge 2 ]
+        then
+            tcert=$(parse_cnf 'sst' 'tca')
+            tpem=$(parse_cnf 'sst' 'tcert')
+            tkey=$(parse_cnf 'sst' 'tkey')
+        fi
+        if [ "$tmode" != 'DISABLED' ]
         then # backward-incompatible behavior
-            check_server_ssl_config "sst"
             if [ -z "$tpem" -a -z "$tkey" -a -z "$tcert" ]
-            then # no new-stype SSL config in [sst], try server-wide SSL config
-                check_server_ssl_config "mysqld.$WSREP_SST_OPT_SUFFIX_VALUE"
+            then # no old-style SSL config in [sst]
+                check_server_ssl_config 'sst'
                 if [ -z "$tpem" -a -z "$tkey" -a -z "$tcert" ]
-                then
-                    check_server_ssl_config "mysqld"
+                then # no new-stype SSL config in [sst], try server-wide SSL config
+                    check_server_ssl_config '--mysqld'
                 fi
             fi
+            if [ 0 -eq $encrypt -a -n "$tpem" -a -n "$tkey" ]
+            then
+                encrypt=3 # enable cert/key SSL encyption
+
+                # avoid CA verification if not set explicitly:
+                # nodes may happen to have different CA if self-generated
+                # zeroing up tcert does the trick
+                local mode=$(parse_cnf 'sst' 'ssl-mode')
+                [ "${tmode#VERIFY}" != "$tmode" ] || tcert=""
+            fi
         fi
     fi
+
+    if [ $encrypt -eq 1 ]; then
+        # Refer to http://www.percona.com/doc/percona-xtradb-cluster/manual/xtrabackup_sst.html
+        ealgo=$(parse_cnf xtrabackup encrypt "")
+        if [ -z "$ealgo" ]; then
+            ealgo=$(parse_cnf sst encrypt-algo "")
+            ekey=$(parse_cnf sst encrypt-key "")
+            ekeyfile=$(parse_cnf sst encrypt-key-file "")
+        else
+            ekey=$(parse_cnf xtrabackup encrypt-key "")
+            ekeyfile=$(parse_cnf xtrabackup encrypt-key-file "")
+        fi
+    fi
+
     wsrep_log_info "SSL configuration: CA='"$tcert"', CERT='"$tpem"'," \
                    "KEY='"$tkey"', MODE='"$tmode"', encrypt="$encrypt
 
@@ -414,19 +403,9 @@ read_cnf()
     ttime=$(parse_cnf sst time 0)
     cpat=$(parse_cnf sst cpat '.*galera\.cache$\|.*sst_in_progress$\|.*\.sst$\|.*gvwstate\.dat$\|.*grastate\.dat$\|.*\.err$\|.*\.log$\|.*RPM_UPGRADE_MARKER$\|.*RPM_UPGRADE_HISTORY$')
     [[ $OS == "FreeBSD" ]] && cpat=$(parse_cnf sst cpat '.*galera\.cache$|.*sst_in_progress$|.*\.sst$|.*gvwstate\.dat$|.*grastate\.dat$|.*\.err$|.*\.log$|.*RPM_UPGRADE_MARKER$|.*RPM_UPGRADE_HISTORY$')
-    ealgo=$(parse_cnf xtrabackup encrypt "")
-    ekey=$(parse_cnf xtrabackup encrypt-key "")
-    ekeyfile=$(parse_cnf xtrabackup encrypt-key-file "")
     scomp=$(parse_cnf sst compressor "")
     sdecomp=$(parse_cnf sst decompressor "")
 
-    # Refer to http://www.percona.com/doc/percona-xtradb-cluster/manual/xtrabackup_sst.html 
-    if [[ -z $ealgo ]];then
-        ealgo=$(parse_cnf sst encrypt-algo "")
-        ekey=$(parse_cnf sst encrypt-key "")
-        ekeyfile=$(parse_cnf sst encrypt-key-file "")
-    fi
-
     rlimit=$(parse_cnf sst rlimit "")
     uextra=$(parse_cnf sst use-extra 0)
     speciald=$(parse_cnf sst sst-special-dirs 1)
@@ -440,42 +419,41 @@ read_cnf()
     sstlogarchive=$(parse_cnf sst sst-log-archive 1)
     sstlogarchivedir=$(parse_cnf sst sst-log-archive-dir "/tmp/sst_log_archive")
 
-    if [[ $speciald -eq 0 ]];then 
+    if [[ $speciald -eq 0 ]];then
         wsrep_log_error "sst-special-dirs equal to 0 is not supported, falling back to 1"
         speciald=1
-    fi 
+    fi
 
-    if [[ $ssyslog -ne -1 ]];then 
-        if $MY_PRINT_DEFAULTS mysqld_safe | tr '_' '-' | grep -q -- "--syslog";then 
+    if [[ $ssyslog -ne -1 ]];then
+        if $MY_PRINT_DEFAULTS mysqld_safe | grep -q -- "--syslog";then
             ssyslog=1
         fi
     fi
 
     if [[ $encrypt -eq 1 ]]; then
         wsrep_log_error "Xtrabackup-based encryption is currently not" \
-                        "supported with MariaBackup"
+            "supported with MariaBackup"
         exit 2
     fi
 }
 
 get_stream()
 {
-    if [[ $sfmt == 'mbstream' || $sfmt == 'xbstream' ]];then
+    if [ "$sfmt" = 'mbstream' -o "$sfmt" = 'xbstream' ]; then
         wsrep_log_info "Streaming with ${sfmt}"
-        if [[ "$WSREP_SST_OPT_ROLE"  == "joiner" ]];then
-            strmcmd="${XBSTREAM_BIN} -x"
+        if [ "$WSREP_SST_OPT_ROLE" = 'joiner' ]; then
+            strmcmd="$MBSTREAM_BIN -x"
         else
-            strmcmd="${XBSTREAM_BIN} -c \${INFO_FILE}"
+            strmcmd="$MBSTREAM_BIN -c '$INFO_FILE'"
         fi
     else
         sfmt="tar"
         wsrep_log_info "Streaming with tar"
-        if [[ "$WSREP_SST_OPT_ROLE"  == "joiner" ]];then
-            strmcmd="tar xfi - "
+        if [ "$WSREP_SST_OPT_ROLE" = 'joiner' ]]; then
+            strmcmd="tar xfi -"
         else
-            strmcmd="tar cf - \${INFO_FILE} "
+            strmcmd="tar cf - '$INFO_FILE'"
         fi
-
     fi
 }
 
@@ -497,33 +475,32 @@ cleanup_joiner()
 {
     # Since this is invoked just after exit NNN
     local estatus=$?
-    if [[ $estatus -ne 0 ]];then 
+    if [ $estatus -ne 0 ]; then
         wsrep_log_error "Cleanup after exit with status:$estatus"
-    elif [ "${WSREP_SST_OPT_ROLE}" = "joiner" ];then
+    elif [ "${WSREP_SST_OPT_ROLE}" = 'joiner' ]; then
         wsrep_log_info "Removing the sst_in_progress file"
         wsrep_cleanup_progress_file
     fi
-    if [[ -n $progress && -p $progress ]];then 
+    if [ -n "$progress" -a -p "$progress" ]; then
         wsrep_log_info "Cleaning up fifo file $progress"
-        rm $progress
+        rm "$progress"
     fi
-    if [[ -n ${STATDIR:-} ]];then 
-       [[ -d $STATDIR ]] && rm -rf $STATDIR
+
+    if [ -n "$STATDIR" ]; then
+       [ -d "$STATDIR" ] && rm -rf "$STATDIR"
     fi
 
-    # Final cleanup 
+    # Final cleanup
     pgid=$(ps -o pgid= $$ | grep -o '[0-9]*')
 
     # This means no setsid done in mysqld.
     # We don't want to kill mysqld here otherwise.
     if [[ $$ -eq $pgid ]];then
-
         # This means a signal was delivered to the process.
-        # So, more cleanup. 
-        if [[ $estatus -ge 128 ]];then 
+        # So, more cleanup.
+        if [[ $estatus -ge 128 ]];then
             kill -KILL -$$ || true
         fi
-
     fi
 
     exit $estatus
@@ -539,57 +516,54 @@ cleanup_donor()
 {
     # Since this is invoked just after exit NNN
     local estatus=$?
-    if [[ $estatus -ne 0 ]];then 
+    if [ $estatus -ne 0 ]; then
         wsrep_log_error "Cleanup after exit with status:$estatus"
     fi
 
-    if [[ -n ${XTRABACKUP_PID:-} ]];then 
+    if [ -n "$XTRABACKUP_PID" ]; then
         if check_pid $XTRABACKUP_PID
         then
             wsrep_log_error "xtrabackup process is still running. Killing..."
             kill_xtrabackup
         fi
-
     fi
-    rm -f ${DATA}/${IST_FILE} || true
 
-    if [[ -n $progress && -p $progress ]];then 
+    rm -f "$DATA/$IST_FILE" || true
+
+    if [ -n "$progress" -a -p "$progress" ]; then
         wsrep_log_info "Cleaning up fifo file $progress"
-        rm -f $progress || true
+        rm -f "$progress" || true
     fi
 
     wsrep_log_info "Cleaning up temporary directories"
 
-    if [[ -n $xtmpdir ]];then 
-       [[ -d $xtmpdir ]] &&  rm -rf $xtmpdir || true
+    if [ -n "$xtmpdir" ]; then
+       [ -d "$xtmpdir" ] && rm -rf "$xtmpdir" || true
     fi
 
-    if [[ -n $itmpdir ]];then 
-       [[ -d $itmpdir ]] &&  rm -rf $itmpdir || true
+    if [ -n "$itmpdir" ]; then
+       [ -d "$itmpdir" ] && rm -rf "$itmpdir" || true
     fi
 
-    # Final cleanup 
+    # Final cleanup
     pgid=$(ps -o pgid= $$ | grep -o '[0-9]*')
 
     # This means no setsid done in mysqld.
     # We don't want to kill mysqld here otherwise.
     if [[ $$ -eq $pgid ]];then
-
         # This means a signal was delivered to the process.
-        # So, more cleanup. 
-        if [[ $estatus -ge 128 ]];then 
+        # So, more cleanup.
+        if [[ $estatus -ge 128 ]];then
             kill -KILL -$$ || true
         fi
-
     fi
 
     exit $estatus
-
 }
 
 kill_xtrabackup()
 {
-    local PID=$(cat $XTRABACKUP_PID)
+    local PID=$(cat "$XTRABACKUP_PID")
     [ -n "$PID" -a "0" != "$PID" ] && kill $PID && (kill $PID && kill -9 $PID) || :
     wsrep_log_info "Removing xtrabackup pid file $XTRABACKUP_PID"
     rm -f "$XTRABACKUP_PID" || true
@@ -597,11 +571,11 @@ kill_xtrabackup()
 
 setup_ports()
 {
-    SST_PORT=${WSREP_SST_OPT_ADDR_PORT}
-    if [[ "$WSREP_SST_OPT_ROLE"  == "donor" ]];then
-        REMOTEIP=${WSREP_SST_OPT_HOST}
-        lsn=${WSREP_SST_OPT_LSN}
-        sst_ver=${WSREP_SST_OPT_SST_VER}
+    SST_PORT="$WSREP_SST_OPT_PORT"
+    if [ "$WSREP_SST_OPT_ROLE" = "donor" ]; then
+        REMOTEIP="${WSREP_SST_OPT_HOST}"
+        lsn="${WSREP_SST_OPT_LSN}"
+        sst_ver="${WSREP_SST_OPT_SST_VER}"
     fi
 }
 
@@ -609,12 +583,12 @@ setup_ports()
 # (regardless of timeout)
 wait_for_listen()
 {
-    local PORT=$1
-    local ADDR=$2
-    local MODULE=$3
+    local PORT="$1"
+    local ADDR="$2"
+    local MODULE="$3"
     for i in {1..50}
     do
-	if [ "$OS" = "FreeBSD" ];then
+        if [ "$OS" = "FreeBSD" ];then
             sockstat -46lp $PORT | grep -qE "^[^ ]* *(socat|nc) *[^ ]* *[^ ]* *[^ ]* *[^ ]*:$PORT" && break
         else
             ss -p state listening "( sport = :$PORT )" | grep -qE 'socat|nc' && break
@@ -627,116 +601,115 @@ wait_for_listen()
 check_extra()
 {
     local use_socket=1
-    if [[ $uextra -eq 1 ]];then 
-        if $MY_PRINT_DEFAULTS --mysqld | tr '_' '-' | grep -- "--thread-handling=" | grep -q 'pool-of-threads';then 
-            local eport=$($MY_PRINT_DEFAULTS --mysqld | tr '_' '-' | grep -- "--extra-port=" | cut -d= -f2)
-            if [[ -n $eport ]];then 
+    if [ $uextra -eq 1 ]; then
+        local thread_handling=$(parse_cnf '--mysqld' 'thread-handling')
+        if [ "$thread_handling" = 'pool-of-threads' ]; then
+            local eport=$(parse_cnf '--mysqld' 'extra-port')
+            if [ -n "$eport" ]; then
                 # Xtrabackup works only locally.
-                # Hence, setting host to 127.0.0.1 unconditionally. 
+                # Hence, setting host to 127.0.0.1 unconditionally.
                 wsrep_log_info "SST through extra_port $eport"
                 INNOEXTRA+=" --host=127.0.0.1 --port=$eport"
                 use_socket=0
-            else 
+            else
                 wsrep_log_error "Extra port $eport null, failing"
                 exit 1
             fi
-        else 
+        else
             wsrep_log_info "Thread pool not set, ignore the option use_extra"
         fi
     fi
-    if [[ $use_socket -eq 1 ]] && [[ -n "$WSREP_SST_OPT_SOCKET" ]];then
-        INNOEXTRA+=" --socket=$WSREP_SST_OPT_SOCKET"
+    if [ $use_socket -eq 1 -a -n "$WSREP_SST_OPT_SOCKET" ]; then
+        INNOEXTRA+=" --socket='$WSREP_SST_OPT_SOCKET'"
     fi
 }
 
 recv_joiner()
 {
-    local dir=$1
-    local msg=$2 
+    local dir="$1"
+    local msg="$2"
     local tmt=$3
     local checkf=$4
     local ltcmd
 
-    if [[ ! -d ${dir} ]];then
+    if [ ! -d "$dir" ]; then
         # This indicates that IST is in progress
         return
     fi
 
-    pushd ${dir} 1>/dev/null
+    pushd "$dir" 1>/dev/null
     set +e
 
-    if [[ $tmt -gt 0 ]] && command -v timeout >/dev/null;then
-        if timeout --help | grep -q -- '-k';then 
+    if [ $tmt -gt 0 -a -x "$(command -v timeout)" ]; then
+        if timeout --help | grep -q -- '-k'; then
             ltcmd="timeout -k $(( tmt+10 )) $tmt $tcmd"
-        else 
+        else
             ltcmd="timeout -s9 $tmt $tcmd"
         fi
         timeit "$msg" "$ltcmd | $strmcmd; RC=( "\${PIPESTATUS[@]}" )"
-    else 
+    else
         timeit "$msg" "$tcmd | $strmcmd; RC=( "\${PIPESTATUS[@]}" )"
     fi
 
     set -e
-    popd 1>/dev/null 
+    popd 1>/dev/null
 
-    if [[ ${RC[0]} -eq 124 ]];then 
+    if [[ ${RC[0]} -eq 124 ]];then
         wsrep_log_error "Possible timeout in receiving first data from " \
                         "donor in gtid stage: exit codes: ${RC[@]}"
         exit 32
     fi
 
-    for ecode in "${RC[@]}";do 
-        if [[ $ecode -ne 0 ]];then 
+    for ecode in "${RC[@]}";do
+        if [[ $ecode -ne 0 ]];then
             wsrep_log_error "Error while getting data from donor node: " \
                             "exit codes: ${RC[@]}"
             exit 32
         fi
     done
 
-    if [[ $checkf -eq 1 ]]; then
-        if [[ ! -r "${MAGIC_FILE}" ]];then
+    if [ $checkf -eq 1 ]; then
+        if [ ! -r "$MAGIC_FILE" ]; then
             # this message should cause joiner to abort
             wsrep_log_error "receiving process ended without creating " \
                             "'${MAGIC_FILE}'"
-            wsrep_log_info "Contents of datadir" 
+            wsrep_log_info "Contents of datadir"
             wsrep_log_info "$(ls -l ${dir}/*)"
             exit 32
         fi
 
         # check donor supplied secret
-        SECRET=$(grep "$SECRET_TAG " ${MAGIC_FILE} 2>/dev/null | cut -d ' ' -f 2)
-        if [[ $SECRET != $MY_SECRET ]]; then
+        SECRET=$(grep "$SECRET_TAG " "$MAGIC_FILE" 2>/dev/null | cut -d ' ' -f 2)
+        if [ "$SECRET" != "$MY_SECRET" ]; then
             wsrep_log_error "Donor does not know my secret!"
             wsrep_log_info "Donor:'$SECRET', my:'$MY_SECRET'"
             exit 32
         fi
 
         # remove secret from magic file
-        grep -v "$SECRET_TAG " ${MAGIC_FILE} > ${MAGIC_FILE}.new
-        mv ${MAGIC_FILE}.new ${MAGIC_FILE}
+        grep -v "$SECRET_TAG " "$MAGIC_FILE" > "$MAGIC_FILE.new"
+        mv "$MAGIC_FILE.new" "$MAGIC_FILE"
     fi
 }
 
-
 send_donor()
 {
-    local dir=$1
-    local msg=$2 
+    local dir="$1"
+    local msg="$2"
 
-    pushd ${dir} 1>/dev/null
+    pushd "$dir" 1>/dev/null
     set +e
     timeit "$msg" "$strmcmd | $tcmd; RC=( "\${PIPESTATUS[@]}" )"
     set -e
-    popd 1>/dev/null 
+    popd 1>/dev/null
 
-    for ecode in "${RC[@]}";do 
-        if [[ $ecode -ne 0 ]];then 
+    for ecode in "${RC[@]}";do
+        if [[ $ecode -ne 0 ]];then
             wsrep_log_error "Error while sending data to joiner node: " \
                             "exit codes: ${RC[@]}"
             exit 32
         fi
     done
-
 }
 
 monitor_process()
@@ -744,26 +717,22 @@ monitor_process()
     local sst_stream_pid=$1
 
     while true ; do
-
         if ! ps -p "${WSREP_SST_OPT_PARENT}" &>/dev/null; then
-            wsrep_log_error "Parent mysqld process (PID:${WSREP_SST_OPT_PARENT}) terminated unexpectedly." 
+            wsrep_log_error "Parent mysqld process (PID:${WSREP_SST_OPT_PARENT}) terminated unexpectedly."
             exit 32
         fi
-
         if ! ps -p "${sst_stream_pid}" &>/dev/null; then
             break
         fi
-
         sleep 0.1
-
     done
 }
 
-wsrep_check_programs "$INNOBACKUPEX_BIN"
+wsrep_check_programs "$MARIABACKUP_BIN"
 
 rm -f "${MAGIC_FILE}"
 
-if [[ ! ${WSREP_SST_OPT_ROLE} == 'joiner' && ! ${WSREP_SST_OPT_ROLE} == 'donor' ]];then 
+if [ "$WSREP_SST_OPT_ROLE" != 'joiner' -a "$WSREP_SST_OPT_ROLE" != 'donor' ]; then
     wsrep_log_error "Invalid role ${WSREP_SST_OPT_ROLE}"
     exit 22
 fi
@@ -771,69 +740,59 @@ fi
 read_cnf
 setup_ports
 
-if ${INNOBACKUPEX_BIN} /tmp --help 2>/dev/null | grep -q -- '--version-check'; then 
-    disver="--no-version-check"
+if "${MARIABACKUP_BIN}" --help 2>/dev/null | grep -q -- '--version-check'; then
+    disver='--no-version-check'
 fi
 
-iopts+=" --databases-exclude=\"lost+found\""
+iopts+=" --databases-exclude='lost+found'"
 
-if [[ ${FORCE_FTWRL:-0} -eq 1 ]];then 
+if [ ${FORCE_FTWRL:-0} -eq 1 ]; then
     wsrep_log_info "Forcing FTWRL due to environment variable FORCE_FTWRL equal to $FORCE_FTWRL"
-    iopts+=" --no-backup-locks"
+    iopts+=' --no-backup-locks'
 fi
 
-INNOEXTRA=
-
-INNODB_DATA_HOME_DIR=${INNODB_DATA_HOME_DIR:-""}
-# Try to set INNODB_DATA_HOME_DIR from the command line:
-if [ ! -z "$INNODB_DATA_HOME_DIR_ARG" ]; then
-    INNODB_DATA_HOME_DIR=$INNODB_DATA_HOME_DIR_ARG
-fi
-# if no command line arg and INNODB_DATA_HOME_DIR environment variable
+# if no command line argument and INNODB_DATA_HOME_DIR environment variable
 # is not set, try to get it from my.cnf:
 if [ -z "$INNODB_DATA_HOME_DIR" ]; then
-    INNODB_DATA_HOME_DIR=$(parse_cnf mysqld$WSREP_SST_OPT_SUFFIX_VALUE innodb-data-home-dir '')
-fi
-if [ -z "$INNODB_DATA_HOME_DIR" ]; then
-    INNODB_DATA_HOME_DIR=$(parse_cnf --mysqld innodb-data-home-dir '')
-fi
-if [ ! -z "$INNODB_DATA_HOME_DIR" ]; then
-   INNOEXTRA+=" --innodb-data-home-dir=$INNODB_DATA_HOME_DIR"
+    INNODB_DATA_HOME_DIR=$(parse_cnf '--mysqld' 'innodb-data-home-dir')
 fi
 
+OLD_PWD="$(pwd)"
+
 if [ -n "$INNODB_DATA_HOME_DIR" ]; then
     # handle both relative and absolute paths
-    INNODB_DATA_HOME_DIR=$(cd $DATA; mkdir -p "$INNODB_DATA_HOME_DIR"; cd $INNODB_DATA_HOME_DIR; pwd -P)
+    INNODB_DATA_HOME_DIR=$(cd "$DATA"; mkdir -p "$INNODB_DATA_HOME_DIR"; cd "$INNODB_DATA_HOME_DIR"; pwd -P)
 else
     # default to datadir
-    INNODB_DATA_HOME_DIR=$(cd $DATA; pwd -P)
+    INNODB_DATA_HOME_DIR=$(cd "$DATA"; pwd -P)
 fi
 
-if [[ $ssyslog -eq 1 ]];then 
+cd "$OLD_PWD"
+
+if [[ $ssyslog -eq 1 ]];then
 
-    if ! command -v logger >/dev/null;then
+    if [ ! -x "$(command -v logger)" ]; then
         wsrep_log_error "logger not in path: $PATH. Ignoring"
     else
-
-        wsrep_log_info "Logging all stderr of SST/Innobackupex to syslog"
+        wsrep_log_info "Logging all stderr of SST/mariabackup to syslog"
 
         exec 2> >(logger -p daemon.err -t ${ssystag}wsrep-sst-$WSREP_SST_OPT_ROLE)
 
         wsrep_log_error()
         {
-            logger  -p daemon.err -t ${ssystag}wsrep-sst-$WSREP_SST_OPT_ROLE "$@" 
+            logger -p daemon.err -t ${ssystag}wsrep-sst-$WSREP_SST_OPT_ROLE "$@"
         }
 
         wsrep_log_info()
         {
-            logger  -p daemon.info -t ${ssystag}wsrep-sst-$WSREP_SST_OPT_ROLE "$@" 
+            logger -p daemon.info -t ${ssystag}wsrep-sst-$WSREP_SST_OPT_ROLE "$@"
         }
-
-        INNOAPPLY="${INNOBACKUPEX_BIN} --prepare $disver $iapts \$INNOEXTRA --target-dir=\${DATA} --mysqld-args \$WSREP_SST_OPT_MYSQLD  2>&1 | logger -p daemon.err -t ${ssystag}innobackupex-apply"
-        INNOMOVE="${INNOBACKUPEX_BIN} ${WSREP_SST_OPT_CONF} --move-back $disver $impts --force-non-empty-directories --target-dir=\${DATA} 2>&1 | logger -p daemon.err -t ${ssystag}innobackupex-move"
-        INNOBACKUP="${INNOBACKUPEX_BIN} ${WSREP_SST_OPT_CONF} --backup $disver $iopts \$tmpopts \$INNOEXTRA --galera-info --stream=\$sfmt --target-dir=\$itmpdir --mysqld-args \$WSREP_SST_OPT_MYSQLD 2> >(logger -p daemon.err -t ${ssystag}innobackupex-backup)"
     fi
 
+    INNOAPPLY="2>&1 | logger -p daemon.err -t ${ssystag}innobackupex-apply"
+    INNOMOVE="2>&1 | logger -p daemon.err -t ${ssystag}innobackupex-move"
+    INNOBACKUP="2> >(logger -p daemon.err -t ${ssystag}innobackupex-backup)"
+
 else
 
 if [[ "$sstlogarchive" -eq 1 ]]
@@ -841,63 +800,71 @@ then
     ARCHIVETIMESTAMP=$(date "+%Y.%m.%d-%H.%M.%S.%N")
     newfile=""
 
-    if [[ ! -z "$sstlogarchivedir" ]]
+    if [ -n "$sstlogarchivedir" ]
     then
-        if [[ ! -d "$sstlogarchivedir" ]]
+        if [ ! -d "$sstlogarchivedir" ]
         then
             mkdir -p "$sstlogarchivedir"
         fi
     fi
 
-    if [ -e "${INNOAPPLYLOG}" ]
+    if [ -e "$INNOAPPLYLOG" ]
     then
-        if [[ ! -z "$sstlogarchivedir" ]]
+        if [ -n "$sstlogarchivedir" ]
         then
-            newfile=$sstlogarchivedir/$(basename "${INNOAPPLYLOG}").${ARCHIVETIMESTAMP}
+            newfile="$sstlogarchivedir/$(basename '$INNOAPPLYLOG').$ARCHIVETIMESTAMP"
         else
-            newfile=${INNOAPPLYLOG}.${ARCHIVETIMESTAMP}
+            newfile="$INNOAPPLYLOG.$ARCHIVETIMESTAMP"
         fi
-   
         wsrep_log_info "Moving ${INNOAPPLYLOG} to ${newfile}"
-        mv "${INNOAPPLYLOG}" "${newfile}"
-        gzip "${newfile}"
+        mv "$INNOAPPLYLOG" "$newfile"
+        gzip "$newfile"
     fi
 
-    if [ -e "${INNOMOVELOG}" ]
+    if [ -e "$INNOMOVELOG" ]
     then
-        if [[ ! -z "$sstlogarchivedir" ]]
+        if [ -n "$sstlogarchivedir" ]
         then
-            newfile=$sstlogarchivedir/$(basename "${INNOMOVELOG}").${ARCHIVETIMESTAMP}
+            newfile="$sstlogarchivedir/$(basename '$INNOMOVELOG').$ARCHIVETIMESTAMP"
         else
-            newfile=${INNOMOVELOG}.${ARCHIVETIMESTAMP}
+            newfile="$INNOMOVELOG.$ARCHIVETIMESTAMP"
         fi
-
         wsrep_log_info "Moving ${INNOMOVELOG} to ${newfile}"
-        mv "${INNOMOVELOG}" "${newfile}"
-        gzip "${newfile}"
+        mv "$INNOMOVELOG" "$newfile"
+        gzip "$newfile"
     fi
 
-    if [ -e "${INNOBACKUPLOG}" ]
+    if [ -e "$INNOBACKUPLOG" ]
     then
-        if [[ ! -z "$sstlogarchivedir" ]]
+        if [ -n "$sstlogarchivedir" ]
         then
-            newfile=$sstlogarchivedir/$(basename "${INNOBACKUPLOG}").${ARCHIVETIMESTAMP}
+            newfile="$sstlogarchivedir/$(basename '$INNOBACKUPLOG').$ARCHIVETIMESTAMP"
         else
-            newfile=${INNOBACKUPLOG}.${ARCHIVETIMESTAMP}
+            newfile="$INNOBACKUPLOG.$ARCHIVETIMESTAMP"
         fi
-
         wsrep_log_info "Moving ${INNOBACKUPLOG} to ${newfile}"
-        mv "${INNOBACKUPLOG}" "${newfile}"
-        gzip "${newfile}"
+        mv "$INNOBACKUPLOG" "$newfile"
+        gzip "$newfile"
     fi
-
 fi
- 
-    INNOAPPLY="${INNOBACKUPEX_BIN} --prepare $disver $iapts \$INNOEXTRA --target-dir=\${DATA} --mysqld-args \$WSREP_SST_OPT_MYSQLD &> ${INNOAPPLYLOG}"
-    INNOMOVE="${INNOBACKUPEX_BIN} ${WSREP_SST_OPT_CONF} --move-back $disver $impts  --move-back --force-non-empty-directories --target-dir=\${DATA} &> ${INNOMOVELOG}"
-    INNOBACKUP="${INNOBACKUPEX_BIN} ${WSREP_SST_OPT_CONF} --backup $disver $iopts \$tmpopts \$INNOEXTRA --galera-info --stream=\$sfmt --target-dir=\$itmpdir --mysqld-args \$WSREP_SST_OPT_MYSQLD 2> ${INNOBACKUPLOG}"
+
+    INNOAPPLY="&> '$INNOAPPLYLOG'"
+    INNOMOVE="&> '$INNOMOVELOG'"
+    INNOBACKUP="2> '$INNOBACKUPLOG'"
+
 fi
 
+setup_commands()
+{
+    local mysqld_args=""
+    if [ -n "$WSREP_SST_OPT_MYSQLD" ]; then
+        mysqld_args="--mysqld-args $WSREP_SST_OPT_MYSQLD"
+    fi
+    INNOAPPLY="$MARIABACKUP_BIN --prepare $disver $iapts $INNOEXTRA --target-dir='$DATA' --datadir='$DATA' $mysqld_args $INNOAPPLY"
+    INNOMOVE="$MARIABACKUP_BIN $WSREP_SST_OPT_CONF --move-back $disver $impts --force-non-empty-directories --target-dir='$DATA' --datadir='${TDATA:-$DATA}' $INNOMOVE"
+    INNOBACKUP="$MARIABACKUP_BIN $WSREP_SST_OPT_CONF --backup $disver $iopts $tmpopts $INNOEXTRA --galera-info --stream='$sfmt' --target-dir='$itmpdir' --datadir='$DATA' $mysqld_args $INNOBACKUP"
+}
+
 get_stream
 get_transfer
 
@@ -908,31 +875,30 @@ then
     if [ $WSREP_SST_OPT_BYPASS -eq 0 ]
     then
         usrst=0
-        if [[ -z $sst_ver ]];then 
+        if [ -z "$sst_ver" ]; then
             wsrep_log_error "Upgrade joiner to 5.6.21 or higher for backup locks support"
             wsrep_log_error "The joiner is not supported for this version of donor"
             exit 93
         fi
 
-        if [[ -z $(parse_cnf mysqld$WSREP_SST_OPT_SUFFIX_VALUE tmpdir "") && \
-              -z $(parse_cnf --mysqld tmpdir "") && \
-              -z $(parse_cnf xtrabackup tmpdir "") ]]; then
+        if [ -z "$(parse_cnf --mysqld tmpdir)" -a \
+             -z "$(parse_cnf xtrabackup tmpdir)" ]; then
             xtmpdir=$(mktemp -d)
-            tmpopts="--tmpdir=$xtmpdir"
+            tmpopts="--tmpdir='$xtmpdir'"
             wsrep_log_info "Using $xtmpdir as xtrabackup temporary directory"
         fi
 
         itmpdir=$(mktemp -d)
-        wsrep_log_info "Using $itmpdir as innobackupex temporary directory"
+        wsrep_log_info "Using $itmpdir as mariabackup temporary directory"
 
-        if [[ -n "${WSREP_SST_OPT_USER:-}" && "$WSREP_SST_OPT_USER" != "(null)" ]]; then
-           INNOEXTRA+=" --user=$WSREP_SST_OPT_USER"
+        if [ -n "$WSREP_SST_OPT_USER" ]; then
+           INNOEXTRA+=" --user='$WSREP_SST_OPT_USER'"
            usrst=1
         fi
 
-        if [ -n "${WSREP_SST_OPT_PSWD:-}" ]; then
-            export MYSQL_PWD=$WSREP_SST_OPT_PSWD
-        elif [[ $usrst -eq 1 ]];then
+        if [ -n "$WSREP_SST_OPT_PSWD" ]; then
+            export MYSQL_PWD="$WSREP_SST_OPT_PSWD"
+        elif [ $usrst -eq 1 ]; then
             # Empty password, used for testing, debugging etc.
             unset MYSQL_PWD
         fi
@@ -943,32 +909,32 @@ then
 
         # Store donor's wsrep GTID (state ID) and wsrep_gtid_domain_id
         # (separated by a space).
-        echo "${WSREP_SST_OPT_GTID} ${WSREP_SST_OPT_GTID_DOMAIN_ID}" > "${MAGIC_FILE}"
+        echo "$WSREP_SST_OPT_GTID $WSREP_SST_OPT_GTID_DOMAIN_ID" > "$MAGIC_FILE"
 
-        if [[ -n ${WSREP_SST_OPT_REMOTE_PSWD} ]]; then
+        if [ -n "$WSREP_SST_OPT_REMOTE_PSWD" ]; then
             # Let joiner know that we know its secret
-            echo "$SECRET_TAG ${WSREP_SST_OPT_REMOTE_PSWD}" >> ${MAGIC_FILE}
+            echo "$SECRET_TAG $WSREP_SST_OPT_REMOTE_PSWD" >> "$MAGIC_FILE"
         fi
 
         ttcmd="$tcmd"
 
-        if [[ $encrypt -eq 1 ]];then
-            if [[ -n $scomp ]];then 
-                tcmd=" $ecmd | $scomp | $tcmd "
-            else 
-                tcmd=" $ecmd | $tcmd "
-            fi
-        elif [[ -n $scomp ]];then 
-            tcmd=" $scomp | $tcmd "
+        if [ -n "$scomp" ]; then
+            tcmd="$scomp | $tcmd"
+        fi
+
+        get_keys
+        if [ $encrypt -eq 1 ]; then
+            tcmd="$ecmd | $tcmd"
         fi
 
-        send_donor $DATA "${stagemsg}-gtid"
+        send_donor "$DATA" "${stagemsg}-gtid"
 
         tcmd="$ttcmd"
-        if [[ -n $progress ]];then 
+
+        if [ -n "$progress" ]; then
             get_footprint
             tcmd="$pcmd | $tcmd"
-        elif [[ -n $rlimit ]];then 
+        elif [ -n "$rlimit" ]; then
             adjust_progress
             tcmd="$pcmd | $tcmd"
         fi
@@ -976,29 +942,29 @@ then
         wsrep_log_info "Sleeping before data transfer for SST"
         sleep 10
 
-        wsrep_log_info "Streaming the backup to joiner at ${REMOTEIP} ${SST_PORT:-4444}"
+        wsrep_log_info "Streaming the backup to joiner at ${REMOTEIP}:${SST_PORT}"
 
-        if [[ -n $scomp ]];then 
+        if [ -n "$scomp" ]; then
             tcmd="$scomp | $tcmd"
         fi
 
+        setup_commands
         set +e
         timeit "${stagemsg}-SST" "$INNOBACKUP | $tcmd; RC=( "\${PIPESTATUS[@]}" )"
         set -e
 
         if [ ${RC[0]} -ne 0 ]; then
-          wsrep_log_error "${INNOBACKUPEX_BIN} finished with error: ${RC[0]}. " \
-                          "Check syslog or ${INNOBACKUPLOG} for details"
-          exit 22
-        elif [[ ${RC[$(( ${#RC[@]}-1 ))]} -eq 1 ]];then 
-          wsrep_log_error "$tcmd finished with error: ${RC[1]}"
-          exit 22
+            wsrep_log_error "${MARIABACKUP_BIN} finished with error: ${RC[0]}. " \
+                            "Check syslog or ${INNOBACKUPLOG} for details"
+            exit 22
+        elif [[ ${RC[$(( ${#RC[@]}-1 ))]} -eq 1 ]]; then
+            wsrep_log_error "$tcmd finished with error: ${RC[1]}"
+            exit 22
         fi
 
-        # innobackupex implicitly writes PID to fixed location in $xtmpdir
+        # mariabackup implicitly writes PID to fixed location in $xtmpdir
         XTRABACKUP_PID="$xtmpdir/xtrabackup_pid"
 
-
     else # BYPASS FOR IST
 
         wsrep_log_info "Bypassing the SST for IST"
@@ -1006,21 +972,21 @@ then
 
         # Store donor's wsrep GTID (state ID) and wsrep_gtid_domain_id
         # (separated by a space).
-        echo "${WSREP_SST_OPT_GTID} ${WSREP_SST_OPT_GTID_DOMAIN_ID}" > "${MAGIC_FILE}"
-        echo "1" > "${DATA}/${IST_FILE}"
+        echo "$WSREP_SST_OPT_GTID $WSREP_SST_OPT_GTID_DOMAIN_ID" > "$MAGIC_FILE"
+        echo "1" > "$DATA/$IST_FILE"
+
+        if [ -n "$scomp" ]; then
+            tcmd="$scomp | $tcmd"
+        fi
+
         get_keys
-        if [[ $encrypt -eq 1 ]];then
-            if [[ -n $scomp ]];then 
-                tcmd=" $ecmd | $scomp | $tcmd "
-            else
-                tcmd=" $ecmd | $tcmd "
-            fi
-        elif [[ -n $scomp ]];then 
-            tcmd=" $scomp | $tcmd "
+        if [ $encrypt -eq 1 ]; then
+            tcmd="$ecmd | $tcmd"
         fi
-        strmcmd+=" \${IST_FILE}"
 
-        send_donor $DATA "${stagemsg}-IST"
+        strmcmd+=" '$IST_FILE'"
+
+        send_donor "$DATA" "${stagemsg}-IST"
 
     fi
 
@@ -1029,37 +995,26 @@ then
 
 elif [ "${WSREP_SST_OPT_ROLE}" = "joiner" ]
 then
-    [[ -e $SST_PROGRESS_FILE ]] && wsrep_log_info "Stale sst_in_progress file: $SST_PROGRESS_FILE"
-    [[ -n $SST_PROGRESS_FILE ]] && touch $SST_PROGRESS_FILE
+    [[ -e "$SST_PROGRESS_FILE" ]] && wsrep_log_info "Stale sst_in_progress file: $SST_PROGRESS_FILE"
+    [[ -n "$SST_PROGRESS_FILE" ]] && touch "$SST_PROGRESS_FILE"
 
-    ib_home_dir=$INNODB_DATA_HOME_DIR
+    ib_home_dir="$INNODB_DATA_HOME_DIR"
 
-    WSREP_LOG_DIR=${WSREP_LOG_DIR:-""}
-    # Try to set WSREP_LOG_DIR from the command line:
-    if [ ! -z "$INNODB_LOG_GROUP_HOME_ARG" ]; then
-        WSREP_LOG_DIR=$INNODB_LOG_GROUP_HOME_ARG
-    fi
-    # if no command line arg and WSREP_LOG_DIR is not set,
+    # if no command line argument and INNODB_LOG_GROUP_HOME is not set,
     # try to get it from my.cnf:
-    if [ -z "$WSREP_LOG_DIR" ]; then
-        WSREP_LOG_DIR=$(parse_cnf mysqld$WSREP_SST_OPT_SUFFIX_VALUE innodb-log-group-home-dir '')
-    fi
-    if [ -z "$WSREP_LOG_DIR" ]; then
-        WSREP_LOG_DIR=$(parse_cnf --mysqld innodb-log-group-home-dir '')
+    if [ -z "$INNODB_LOG_GROUP_HOME" ]; then
+        INNODB_LOG_GROUP_HOME=$(parse_cnf '--mysqld' 'innodb-log-group-home-dir')
     fi
 
-    ib_log_dir=$WSREP_LOG_DIR
+    ib_log_dir="$INNODB_LOG_GROUP_HOME"
 
-    # Try to set ib_undo_dir from the command line:
-    ib_undo_dir=${INNODB_UNDO_DIR_ARG:-""}
-    # if no command line arg then try to get it from my.cnf:
-    if [ -z "$ib_undo_dir" ]; then
-        ib_undo_dir=$(parse_cnf mysqld$WSREP_SST_OPT_SUFFIX_VALUE innodb-undo-directory "")
-    fi
-    if [ -z "$ib_undo_dir" ]; then
-        ib_undo_dir=$(parse_cnf --mysqld innodb-undo-directory "")
+    # if no command line argument then try to get it from my.cnf:
+    if [ -z "$INNODB_UNDO_DIR" ]; then
+        INNODB_UNDO_DIR=$(parse_cnf '--mysqld' 'innodb-undo-directory')
     fi
 
+    ib_undo_dir="$INNODB_UNDO_DIR"
+
     stagemsg="Joiner-Recv"
 
     sencrypted=1
@@ -1067,161 +1022,157 @@ then
 
     MODULE="xtrabackup_sst"
 
-    rm -f "${DATA}/${IST_FILE}"
+    rm -f "$DATA/$IST_FILE"
 
     # May need xtrabackup_checkpoints later on
-    rm -f ${DATA}/xtrabackup_binary ${DATA}/xtrabackup_galera_info  ${DATA}/ib_logfile0
+    rm -f "$DATA/xtrabackup_binary" "$DATA/xtrabackup_galera_info" "$DATA/ib_logfile0"
 
-    ADDR=${WSREP_SST_OPT_ADDR}
-    if [ -z "${SST_PORT}" ]
-    then
-        SST_PORT=4444
-        if [ "${ADDR#\[}" != "$ADDR" ]; then
-            ADDR="$(echo ${WSREP_SST_OPT_ADDR} | awk -F '\\]:' '{ print $1 }')]:${SST_PORT}"
-        else
-            ADDR="$(echo ${WSREP_SST_OPT_ADDR} | awk -F ':' '{ print $1 }'):${SST_PORT}"
-        fi
-    fi
+    ADDR="$WSREP_SST_OPT_ADDR"
 
-    if [[ "$tmode" = *"VERIFY"* ]]
+    if [ "${tmode#VERIFY}" != "$tmode" ]
     then # backward-incompatible behavior
+        CN=""
         if [ -n "$tpem" ]
         then
             # find out my Common Name
-            wsrep_check_programs openssl
-            CN=$(openssl x509 -noout -subject -in $tpem | \
+            get_openssl
+            if [ -z "$OPENSSL_BINARY" ]; then
+                wsrep_log_error 'openssl not found but it is required for authentication'
+                exit 42
+            fi
+            CN=$("$OPENSSL_BINARY" x509 -noout -subject -in "$tpem" | \
                  tr "," "\n" | grep "CN =" | cut -d= -f2 | sed s/^\ // | \
                  sed s/\ %//)
-        else
-            CN=""
         fi
         MY_SECRET=$(wsrep_gen_secret)
         # Add authentication data to address
         ADDR="$CN:$MY_SECRET@$ADDR"
     else
         MY_SECRET="" # for check down in recv_joiner()
-    fi # tmode == *VERIFY*
+    fi
 
-    wait_for_listen ${SST_PORT} "${ADDR}" ${MODULE} &
+    wait_for_listen "$SST_PORT" "$ADDR" "$MODULE" &
 
     trap sig_joiner_cleanup HUP PIPE INT TERM
     trap cleanup_joiner EXIT
 
-    if [[ -n $progress ]];then 
+    if [ -n "$progress" ]; then
         adjust_progress
         tcmd+=" | $pcmd"
     fi
 
     get_keys
-    if [[ $encrypt -eq 1 && $sencrypted -eq 1 ]];then
-        if [[ -n $sdecomp ]];then 
-            strmcmd=" $sdecomp | $ecmd | $strmcmd"
-        else 
-            strmcmd=" $ecmd | $strmcmd"
+    if [ $encrypt -eq 1 -a $sencrypted -eq 1 ]; then
+        if [ -n "$sdecomp" ]; then
+            strmcmd="$sdecomp | $ecmd | $strmcmd"
+        else
+            strmcmd="$ecmd | $strmcmd"
         fi
-    elif [[ -n $sdecomp ]];then 
-            strmcmd=" $sdecomp | $strmcmd"
+    elif [ -n "$sdecomp" ]; then
+            strmcmd="$sdecomp | $strmcmd"
     fi
 
     STATDIR=$(mktemp -d)
-    MAGIC_FILE="${STATDIR}/${INFO_FILE}"
-    recv_joiner $STATDIR  "${stagemsg}-gtid" $stimeout 1
-
+    MAGIC_FILE="$STATDIR/$INFO_FILE"
+    recv_joiner "$STATDIR" "${stagemsg}-gtid" $stimeout 1
 
     if ! ps -p ${WSREP_SST_OPT_PARENT} &>/dev/null
     then
-        wsrep_log_error "Parent mysqld process (PID:${WSREP_SST_OPT_PARENT}) terminated unexpectedly." 
+        wsrep_log_error "Parent mysqld process (PID:${WSREP_SST_OPT_PARENT}) terminated unexpectedly."
         exit 32
     fi
 
-    if [ ! -r "${STATDIR}/${IST_FILE}" ]
+    if [ ! -r "$STATDIR/$IST_FILE" ]
     then
 
-        if [[ -d ${DATA}/.sst ]];then
+        if [ -d "$DATA/.sst" ]; then
             wsrep_log_info "WARNING: Stale temporary SST directory: ${DATA}/.sst from previous state transfer. Removing"
-            rm -rf ${DATA}/.sst
+            rm -rf "$DATA/.sst"
         fi
-        mkdir -p ${DATA}/.sst
-        (recv_joiner $DATA/.sst "${stagemsg}-SST" 0 0) &
+        mkdir -p "$DATA/.sst"
+        (recv_joiner "$DATA/.sst" "${stagemsg}-SST" 0 0) &
         jpid=$!
         wsrep_log_info "Proceeding with SST"
 
         wsrep_log_info "Cleaning the existing datadir and innodb-data/log directories"
-	if [ "${OS}" = "FreeBSD" ]; then
-            find -E $ib_home_dir $ib_log_dir $ib_undo_dir $DATA -mindepth 1 -prune -regex $cpat -o -exec rm -rfv {} 1>&2 \+
+        if [ "${OS}" = "FreeBSD" ]; then
+            find -E ${ib_home_dir:+"$ib_home_dir"} \
+                    ${ib_undo_dir:+"$ib_undo_dir"} \
+                    ${ib_log_dir:+"$ib_log_dir"} \
+                    "$DATA" -mindepth 1 -prune -regex "$cpat" -o -exec rm -rfv {} 1>&2 \+
         else
-            find $ib_home_dir $ib_log_dir $ib_undo_dir $DATA -mindepth 1 -prune -regex $cpat -o -exec rm -rfv {} 1>&2 \+
-	fi
-
-        tempdir=$LOG_BIN_ARG
-        if [ -z "$tempdir" ]; then
-            tempdir=$(parse_cnf mysqld$WSREP_SST_OPT_SUFFIX_VALUE log-bin "")
-        fi
-        if [ -z "$tempdir" ]; then
-            tempdir=$(parse_cnf --mysqld log-bin "")
+            find ${ib_home_dir:+"$ib_home_dir"} \
+                 ${ib_undo_dir:+"$ib_undo_dir"} \
+                 ${ib_log_dir:+"$ib_log_dir"} \
+                 "$DATA" -mindepth 1 -prune -regex "$cpat" -o -exec rm -rfv {} 1>&2 \+
         fi
-        if [[ -n ${tempdir:-} ]];then
-            binlog_dir=$(dirname $tempdir)
-            binlog_file=$(basename $tempdir)
-            if [[ -n ${binlog_dir:-} && $binlog_dir != '.' && $binlog_dir != $DATA ]];then
-                pattern="$binlog_dir/$binlog_file\.[0-9]+$"
-                wsrep_log_info "Cleaning the binlog directory $binlog_dir as well"
-                find $binlog_dir -maxdepth 1 -type f -regex $pattern -exec rm -fv {} 1>&2 \+ || true
-                rm $binlog_dir/*.index || true
-            fi
-        fi
-
 
+        get_binlog
 
-        TDATA=${DATA}
-        DATA="${DATA}/.sst"
+        if [ -n "$WSREP_SST_OPT_BINLOG" ]; then
+            binlog_dir=$(dirname "$WSREP_SST_OPT_BINLOG")
+            cd "$binlog_dir"
+            wsrep_log_info "Cleaning the binlog directory $binlog_dir as well"
+            rm -fv "$WSREP_SST_OPT_BINLOG".[0-9]* 1>&2 \+ || true
+            binlog_index="${WSREP_SST_OPT_BINLOG_INDEX%.index}.index"
+            [ -f "$binlog_index" ] && rm -fv "$binlog_index" 1>&2 \+ || true
+            cd "$OLD_PWD"
+        fi
 
+        TDATA="$DATA"
+        DATA="$DATA/.sst"
 
-        MAGIC_FILE="${DATA}/${INFO_FILE}"
+        MAGIC_FILE="$DATA/$INFO_FILE"
         wsrep_log_info "Waiting for SST streaming to complete!"
         monitor_process $jpid
 
         get_proc
 
-        if [[ ! -s ${DATA}/xtrabackup_checkpoints ]];then 
-            wsrep_log_error "xtrabackup_checkpoints missing, failed innobackupex/SST on donor"
+        if [[ ! -s "$DATA/xtrabackup_checkpoints" ]];then
+            wsrep_log_error "xtrabackup_checkpoints missing, failed mariabackup/SST on donor"
             exit 2
         fi
 
-        if test -n "$(find ${DATA} -maxdepth 1 -type f -name '*.qp' -print -quit)";then
+        # Compact backups are not supported by mariabackup
+        if grep -q 'compact = 1' "$DATA/xtrabackup_checkpoints"; then
+            wsrep_log_info "Index compaction detected"
+            wsrel_log_error "Compact backups are not supported by mariabackup"
+            exit 2
+        fi
 
+        qpfiles=$(find "$DATA" -maxdepth 1 -type f -name '*.qp' -print -quit)
+        if [ -n "$qpfiles" ]; then
             wsrep_log_info "Compressed qpress files found"
 
-            if ! command -v qpress >/dev/null;then
+            if [ ! -x "$(command -v qpress)" ]; then
                 wsrep_log_error "qpress not found in path: $PATH"
                 exit 22
             fi
 
-            if [[ -n $progress ]] && pv --help | grep -q 'line-mode';then
-                count=$(find ${DATA} -type f -name '*.qp' | wc -l)
+            if [[ -n "$progress" ]] && pv --help | grep -q 'line-mode';then
+                count=$(find "$DATA" -type f -name '*.qp' | wc -l)
                 count=$(( count*2 ))
-                if pv --help | grep -q FORMAT;then 
+                if pv --help | grep -q FORMAT;then
                     pvopts="-f -s $count -l -N Decompression -F '%N => Rate:%r Elapsed:%t %e Progress: [%b/$count]'"
-                else 
+                else
                     pvopts="-f -s $count -l -N Decompression"
                 fi
                 pcmd="pv $pvopts"
                 adjust_progress
                 dcmd="$pcmd | xargs -n 2 qpress -T${nproc}d"
-            else 
+            else
                 dcmd="xargs -n 2 qpress -T${nproc}d"
             fi
 
-
-            # Decompress the qpress files 
+            # Decompress the qpress files
             wsrep_log_info "Decompression with $nproc threads"
-            timeit "Joiner-Decompression" "find ${DATA} -type f -name '*.qp' -printf '%p\n%h\n' | $dcmd"
+            timeit "Joiner-Decompression" "find '$DATA' -type f -name '*.qp' -printf '%p\n%h\n' | $dcmd"
             extcode=$?
 
             if [[ $extcode -eq 0 ]];then
                 wsrep_log_info "Removing qpress files after decompression"
-                find ${DATA} -type f -name '*.qp' -delete 
-                if [[ $? -ne 0 ]];then 
+                find "$DATA" -type f -name '*.qp' -delete
+                if [[ $? -ne 0 ]];then
                     wsrep_log_error "Something went wrong with deletion of qpress files. Investigate"
                 fi
             else
@@ -1230,58 +1181,57 @@ then
             fi
         fi
 
+        if  [ -n "$WSREP_SST_OPT_BINLOG" ]; then
 
-        if  [[ ! -z $WSREP_SST_OPT_BINLOG ]];then
-
-            BINLOG_DIRNAME=$(dirname $WSREP_SST_OPT_BINLOG)
-            BINLOG_FILENAME=$(basename $WSREP_SST_OPT_BINLOG)
+            BINLOG_DIRNAME=$(dirname "$WSREP_SST_OPT_BINLOG")
+            BINLOG_FILENAME=$(basename "$WSREP_SST_OPT_BINLOG")
 
-            # To avoid comparing data directory and BINLOG_DIRNAME 
-            mv $DATA/${BINLOG_FILENAME}.* $BINLOG_DIRNAME/ 2>/dev/null || true
+            # To avoid comparing data directory and BINLOG_DIRNAME
+            mv "$DATA/$BINLOG_FILENAME".* "$BINLOG_DIRNAME/" 2>/dev/null || true
 
-            pushd $BINLOG_DIRNAME &>/dev/null
-            for bfiles in $(ls -1 ${BINLOG_FILENAME}.[0-9]*);do
-                echo ${BINLOG_DIRNAME}/${bfiles} >> ${BINLOG_FILENAME}.index
+            cd "$BINLOG_DIRNAME"
+            for bfile in $(ls -1 "$BINLOG_FILENAME".[0-9]*); do
+                echo "$BINLOG_DIRNAME/$bfile" >> "${WSREP_SST_OPT_BINLOG_INDEX%.index}.index"
             done
-            popd &> /dev/null
+            cd "$OLD_PWD"
 
         fi
 
         wsrep_log_info "Preparing the backup at ${DATA}"
+        setup_commands
         timeit "Xtrabackup prepare stage" "$INNOAPPLY"
 
-        if [ $? -ne 0 ];
-        then
-            wsrep_log_error "${INNOBACKUPEX_BIN} apply finished with errors. Check syslog or ${INNOAPPLYLOG} for details" 
+        if [ $? -ne 0 ]; then
+            wsrep_log_error "${MARIABACKUP_BIN} apply finished with errors. Check syslog or ${INNOAPPLYLOG} for details"
             exit 22
         fi
 
-        MAGIC_FILE="${TDATA}/${INFO_FILE}"
-        set +e
-        set -e
+        MAGIC_FILE="$TDATA/$INFO_FILE"
         wsrep_log_info "Moving the backup to ${TDATA}"
         timeit "Xtrabackup move stage" "$INNOMOVE"
-        if [[ $? -eq 0 ]];then 
+        if [[ $? -eq 0 ]];then
             wsrep_log_info "Move successful, removing ${DATA}"
-            rm -rf $DATA
-            DATA=${TDATA}
-        else 
+            rm -rf "$DATA"
+            DATA="$TDATA"
+        else
             wsrep_log_error "Move failed, keeping ${DATA} for further diagnosis"
             wsrep_log_error "Check syslog or ${INNOMOVELOG} for details"
             exit 22
         fi
 
+    else
 
-    else 
         wsrep_log_info "${IST_FILE} received from donor: Running IST"
+
     fi
 
-    if [[ ! -r ${MAGIC_FILE} ]];then 
+    if [ ! -r "$MAGIC_FILE" ]; then
         wsrep_log_error "SST magic file ${MAGIC_FILE} not found/readable"
         exit 2
     fi
-    wsrep_log_info "Galera co-ords from recovery: $(cat ${MAGIC_FILE})"
-    cat "${MAGIC_FILE}" # Output : UUID:seqno wsrep_gtid_domain_id
+    wsrep_log_info "Galera co-ords from recovery: $(cat '${MAGIC_FILE}')"
+    cat "$MAGIC_FILE" # Output : UUID:seqno wsrep_gtid_domain_id
+
     wsrep_log_info "Total time on joiner: $totime seconds"
 fi
 
diff --git a/scripts/wsrep_sst_mysqldump.sh b/scripts/wsrep_sst_mysqldump.sh
index 4a5e5bc7e52..3cc52398caa 100644
--- a/scripts/wsrep_sst_mysqldump.sh
+++ b/scripts/wsrep_sst_mysqldump.sh
@@ -1,5 +1,6 @@
 #!/bin/bash -ue
 # Copyright (C) 2009-2015 Codership Oy
+# Copyright (C) 2017-2021 MariaDB
 #
 # This program is free software; you can redistribute it and/or modify
 # it under the terms of the GNU General Public License as published by
@@ -101,12 +102,12 @@ SET_START_POSITION="SET GLOBAL wsrep_start_position='$WSREP_SST_OPT_GTID';"
 SET_WSREP_GTID_DOMAIN_ID=""
 if [ -n $WSREP_SST_OPT_GTID_DOMAIN_ID ]
 then
-  SET_WSREP_GTID_DOMAIN_ID="
-  SET @val = (SELECT GLOBAL_VALUE FROM INFORMATION_SCHEMA.SYSTEM_VARIABLES WHERE VARIABLE_NAME = 'WSREP_GTID_STRICT_MODE' AND GLOBAL_VALUE > 0);
-  SET @stmt = IF (@val IS NOT NULL, 'SET GLOBAL WSREP_GTID_DOMAIN_ID=$WSREP_SST_OPT_GTID_DOMAIN_ID', 'SET @dummy = 0');
-  PREPARE stmt FROM @stmt;
-  EXECUTE stmt;
-  DROP PREPARE stmt;"
+    SET_WSREP_GTID_DOMAIN_ID="
+    SET @val = (SELECT GLOBAL_VALUE FROM INFORMATION_SCHEMA.SYSTEM_VARIABLES WHERE VARIABLE_NAME = 'WSREP_GTID_STRICT_MODE' AND GLOBAL_VALUE > 0);
+    SET @stmt = IF (@val IS NOT NULL, 'SET GLOBAL WSREP_GTID_DOMAIN_ID=$WSREP_SST_OPT_GTID_DOMAIN_ID', 'SET @dummy = 0');
+    PREPARE stmt FROM @stmt;
+    EXECUTE stmt;
+    DROP PREPARE stmt;"
 fi
 
 MYSQL="$MYSQL_CLIENT $WSREP_SST_OPT_CONF "\
@@ -133,16 +134,16 @@ SQL_LOG_BIN_OFF=""
 # Safety check
 if [ "${SERVER_VERSION%%.*}" != '5' ]
 then
-  # If binary logging is enabled on the joiner node, we need to copy donor's
-  # gtid_binlog_state to joiner. In order to do that, a RESET MASTER must be
-  # executed to erase binary logs (if any). Binary logging should also be
-  # turned off for the session so that gtid state does not get altered while
-  # the dump gets replayed on joiner.
-  if [[ "$LOG_BIN" == 'ON' ]]; then
-    RESET_MASTER="SET GLOBAL wsrep_on=OFF; RESET MASTER; SET GLOBAL wsrep_on=ON;"
-    SET_GTID_BINLOG_STATE="SET GLOBAL wsrep_on=OFF; SET @@global.gtid_binlog_state='$GTID_BINLOG_STATE'; SET GLOBAL wsrep_on=ON;"
-    SQL_LOG_BIN_OFF="SET @@session.sql_log_bin=OFF;"
-  fi
+    # If binary logging is enabled on the joiner node, we need to copy donor's
+    # gtid_binlog_state to joiner. In order to do that, a RESET MASTER must be
+    # executed to erase binary logs (if any). Binary logging should also be
+    # turned off for the session so that gtid state does not get altered while
+    # the dump gets replayed on joiner.
+    if [[ "$LOG_BIN" == 'ON' ]]; then
+        RESET_MASTER="SET GLOBAL wsrep_on=OFF; RESET MASTER; SET GLOBAL wsrep_on=ON;"
+        SET_GTID_BINLOG_STATE="SET GLOBAL wsrep_on=OFF; SET @@global.gtid_binlog_state='$GTID_BINLOG_STATE'; SET GLOBAL wsrep_on=ON;"
+        SQL_LOG_BIN_OFF="SET @@session.sql_log_bin=OFF;"
+    fi
 fi
 
 # NOTE: we don't use --routines here because we're dumping mysql.proc table
diff --git a/scripts/wsrep_sst_rsync.sh b/scripts/wsrep_sst_rsync.sh
index 809d3e81e16..92fdc28f643 100644
--- a/scripts/wsrep_sst_rsync.sh
+++ b/scripts/wsrep_sst_rsync.sh
@@ -1,6 +1,7 @@
 #!/bin/bash -ue
 
 # Copyright (C) 2010-2014 Codership Oy
+# Copyright (C) 2017-2021 MariaDB
 #
 # This program is free software; you can redistribute it and/or modify
 # it under the terms of the GNU General Public License as published by
@@ -23,12 +24,13 @@ RSYNC_CONF=                                     # rsync configuration file
 RSYNC_REAL_PID=                                 # rsync process id
 
 OS=$(uname)
-[ "$OS" = "Darwin" ] && export -n LD_LIBRARY_PATH
+[ "$OS" = 'Darwin' ] && export -n LD_LIBRARY_PATH
 
 # Setting the path for lsof on CentOS
 export PATH="/usr/sbin:/sbin:$PATH"
 
 . $(dirname $0)/wsrep_sst_common
+wsrep_check_datadir
 
 wsrep_check_programs rsync
 
@@ -54,13 +56,13 @@ cleanup_joiner()
 # Check whether rsync process is still running.
 check_pid()
 {
-    local pid_file=$1
-    [ -r "$pid_file" ] && ps -p $(cat $pid_file) >/dev/null 2>&1
+    local pid_file="$1"
+    [ -r "$pid_file" ] && ps -p $(cat "$pid_file") >/dev/null 2>&1
 }
 
 check_pid_and_port()
 {
-    local pid_file=$1
+    local pid_file="$1"
     local rsync_pid=$2
     local rsync_addr=$3
     local rsync_port=$4
@@ -73,11 +75,10 @@ check_pid_and_port()
             grep -E '[[:space:]]+(rsync|stunnel)[[:space:]]+'"$rsync_pid" 2>/dev/null)"
         ;;
     *)
-        if ! command -v lsof > /dev/null; then
-          wsrep_log_error "lsof tool not found in PATH! Make sure you have it installed."
-          exit 2 # ENOENT
+        if [ ! -x "$(command -v lsof)" ]; then
+            wsrep_log_error "lsof tool not found in PATH! Make sure you have it installed."
+            exit 2 # ENOENT
         fi
-
         local port_info="$(lsof -i :$rsync_port -Pn 2>/dev/null | \
             grep "(LISTEN)")"
         local is_rsync="$(echo $port_info | \
@@ -96,27 +97,25 @@ check_pid_and_port()
             exit 16 # EBUSY
         fi
     fi
-    check_pid $pid_file && \
+    check_pid "$pid_file" && \
         [ -n "$port_info" ] && [ -n "$is_rsync" ] && \
-        [ $(cat $pid_file) -eq $rsync_pid ]
+        [ $(cat "$pid_file") -eq $rsync_pid ]
 }
 
 is_local_ip()
 {
   local address="$1"
-  local get_addr_bin
-  if ! command -v ifconfig > /dev/null
+  local get_addr_bin="$(command -v ifconfig)"
+  if [ -z "$get_addr_bin" ]
   then
-    get_addr_bin=ip
-    get_addr_bin="$get_addr_bin address show"
-    # Add an slash at the end, so we don't get false positive : 172.18.0.4 matches 172.18.0.41
-    # ip output format is "X.X.X.X/mask"
-    address="${address}/"
+      get_addr_bin="$(command -v ip) address show"
+      # Add an slash at the end, so we don't get false positive : 172.18.0.4 matches 172.18.0.41
+      # ip output format is "X.X.X.X/mask"
+      address="$address/"
   else
-    # Add an space at the end, so we don't get false positive : 172.18.0.4 matches 172.18.0.41
-    # ifconfig output format is "X.X.X.X "
-    get_addr_bin=ifconfig
-    address="$address "
+      # Add an space at the end, so we don't get false positive : 172.18.0.4 matches 172.18.0.41
+      # ifconfig output format is "X.X.X.X "
+      address="$address "
   fi
 
   $get_addr_bin | grep -F "$address" > /dev/null
@@ -135,65 +134,64 @@ BINLOG_TAR_FILE="$WSREP_SST_OPT_DATA/wsrep_sst_binlog.tar"
 BINLOG_N_FILES=1
 rm -f "$BINLOG_TAR_FILE" || :
 
-if ! [ -z $WSREP_SST_OPT_BINLOG ]
-then
-    BINLOG_DIRNAME=$(dirname $WSREP_SST_OPT_BINLOG)
-    BINLOG_FILENAME=$(basename $WSREP_SST_OPT_BINLOG)
-    BINLOG_INDEX_DIRNAME=$(dirname $WSREP_SST_OPT_BINLOG)
-    BINLOG_INDEX_FILENAME=$(basename $WSREP_SST_OPT_BINLOG)
-fi
+get_binlog
 
-if ! [ -z $WSREP_SST_OPT_BINLOG_INDEX ]
-then
-    BINLOG_INDEX_DIRNAME=$(dirname $WSREP_SST_OPT_BINLOG_INDEX)
-    BINLOG_INDEX_FILENAME=$(basename $WSREP_SST_OPT_BINLOG_INDEX)
-    BINLOG_INDEX_FILENAME=${BINLOG_INDEX_FILENAME%.index}.index
+if [ -n "$WSREP_SST_OPT_BINLOG" ]; then
+    BINLOG_DIRNAME=$(dirname "$WSREP_SST_OPT_BINLOG")
+    BINLOG_FILENAME=$(basename "$WSREP_SST_OPT_BINLOG")
 fi
 
-WSREP_LOG_DIR=${WSREP_LOG_DIR:-""}
-# Try to set WSREP_LOG_DIR from the command line:
-if [ ! -z "$INNODB_LOG_GROUP_HOME_ARG" ]; then
-    WSREP_LOG_DIR=$INNODB_LOG_GROUP_HOME_ARG
-fi
-# if no command line arg and WSREP_LOG_DIR is not set,
+# if no command line argument and INNODB_LOG_GROUP_HOME is not set,
 # try to get it from my.cnf:
-if [ -z "$WSREP_LOG_DIR" ]; then
-    WSREP_LOG_DIR=$(parse_cnf mysqld$WSREP_SST_OPT_SUFFIX_VALUE innodb-log-group-home-dir '')
-fi
-if [ -z "$WSREP_LOG_DIR" ]; then
-    WSREP_LOG_DIR=$(parse_cnf --mysqld innodb-log-group-home-dir '')
+if [ -z "$INNODB_LOG_GROUP_HOME" ]; then
+    INNODB_LOG_GROUP_HOME=$(parse_cnf '--mysqld' 'innodb-log-group-home-dir')
 fi
 
+OLD_PWD="$(pwd)"
+
+WSREP_LOG_DIR="$INNODB_LOG_GROUP_HOME"
+
 if [ -n "$WSREP_LOG_DIR" ]; then
     # handle both relative and absolute paths
-    WSREP_LOG_DIR=$(cd $WSREP_SST_OPT_DATA; mkdir -p "$WSREP_LOG_DIR"; cd $WSREP_LOG_DIR; pwd -P)
+    WSREP_LOG_DIR=$(cd "$WSREP_SST_OPT_DATA"; mkdir -p "$WSREP_LOG_DIR"; cd "$WSREP_LOG_DIR"; pwd -P)
 else
     # default to datadir
-    WSREP_LOG_DIR=$(cd $WSREP_SST_OPT_DATA; pwd -P)
+    WSREP_LOG_DIR=$(cd "$WSREP_SST_OPT_DATA"; pwd -P)
 fi
 
-INNODB_DATA_HOME_DIR=${INNODB_DATA_HOME_DIR:-""}
-# Try to set INNODB_DATA_HOME_DIR from the command line:
-if [ ! -z "$INNODB_DATA_HOME_DIR_ARG" ]; then
-    INNODB_DATA_HOME_DIR=$INNODB_DATA_HOME_DIR_ARG
-fi
-# if no command line arg and INNODB_DATA_HOME_DIR environment variable
+cd "$OLD_PWD"
+
+# if no command line argument and INNODB_DATA_HOME_DIR environment variable
 # is not set, try to get it from my.cnf:
 if [ -z "$INNODB_DATA_HOME_DIR" ]; then
-    INNODB_DATA_HOME_DIR=$(parse_cnf mysqld$WSREP_SST_OPT_SUFFIX_VALUE innodb-data-home-dir '')
-fi
-if [ -z "$INNODB_DATA_HOME_DIR" ]; then
-    INNODB_DATA_HOME_DIR=$(parse_cnf --mysqld innodb-data-home-dir '')
+    INNODB_DATA_HOME_DIR=$(parse_cnf '--mysqld' 'innodb-data-home-dir')
 fi
 
 if [ -n "$INNODB_DATA_HOME_DIR" ]; then
     # handle both relative and absolute paths
-    INNODB_DATA_HOME_DIR=$(cd $WSREP_SST_OPT_DATA; mkdir -p "$INNODB_DATA_HOME_DIR"; cd $INNODB_DATA_HOME_DIR; pwd -P)
+    INNODB_DATA_HOME_DIR=$(cd "$WSREP_SST_OPT_DATA"; mkdir -p "$INNODB_DATA_HOME_DIR"; cd "$INNODB_DATA_HOME_DIR"; pwd -P)
+else
+    # default to datadir
+    INNODB_DATA_HOME_DIR=$(cd "$WSREP_SST_OPT_DATA"; pwd -P)
+fi
+
+cd "$OLD_PWD"
+
+# if no command line argument then try to get it from my.cnf:
+if [ -z "$INNODB_UNDO_DIR" ]; then
+    INNODB_UNDO_DIR=$(parse_cnf '--mysqld' 'innodb-undo-directory')
+fi
+
+if [ -n "$INNODB_UNDO_DIR" ]; then
+    # handle both relative and absolute paths
+    INNODB_UNDO_DIR=$(cd "$WSREP_SST_OPT_DATA"; mkdir -p "$INNODB_UNDO_DIR"; cd "$INNODB_UNDO_DIR"; pwd -P)
 else
     # default to datadir
-    INNODB_DATA_HOME_DIR=$(cd $WSREP_SST_OPT_DATA; pwd -P)
+    INNODB_UNDO_DIR=$(cd "$WSREP_SST_OPT_DATA"; pwd -P)
 fi
 
+cd "$OLD_PWD"
+
 # Old filter - include everything except selected
 # FILTER=(--exclude '*.err' --exclude '*.pid' --exclude '*.sock' \
 #         --exclude '*.conf' --exclude core --exclude 'galera.*' \
@@ -208,30 +206,99 @@ FILTER="-f '- /lost+found'
         -f '+ /wsrep_sst_binlog.tar'
         -f '- $INNODB_DATA_HOME_DIR/ib_lru_dump'
         -f '- $INNODB_DATA_HOME_DIR/ibdata*'
-        -f '+ /undo*'
+        -f '+ $INNODB_UNDO_DIR/undo*'
         -f '+ /*/'
         -f '- /*'"
 
-SSTKEY=$(parse_cnf sst tkey "")
-SSTCERT=$(parse_cnf sst tcert "")
+# old-style SSL config
+SSTKEY=$(parse_cnf 'sst' 'tkey')
+SSTCERT=$(parse_cnf 'sst' 'tcert')
+SSTCA=$(parse_cnf 'sst' 'tca')
+
+check_server_ssl_config()
+{
+    local section="$1"
+    SSTKEY=$(parse_cnf "$section" 'ssl-key')
+    SSTCERT=$(parse_cnf "$section" 'ssl-cert')
+    SSTCA=$(parse_cnf "$section" 'ssl-ca')
+}
+
+SSLMODE=$(parse_cnf 'sst' 'ssl-mode' | tr [:lower:] [:upper:])
+
+if [ -z "$SSTKEY" -a -z "$SSTCERT" ]
+then
+    # no old-style SSL config in [sst], check for new one
+    check_server_ssl_config 'sst'
+    if [ -z "$SSTKEY" -a -z "$SSTCERT" ]; then
+        check_server_ssl_config '--mysqld'
+    fi
+fi
+
+if [ -z "$SSLMODE" ]; then
+    # Implicit verification if CA is set and the SSL mode
+    # is not specified by user:
+    if [ -n "$SSTCA" ]; then
+        if [ -x "$(command -v stunnel)" ]; then
+            SSLMODE='VERIFY_CA'
+        fi
+    # Require SSL by default if SSL key and cert are present:
+    elif [ -n "$SSTKEY" -a -n "$SSTCERT" ]; then
+        SSLMODE='REQUIRED'
+    fi
+fi
+
+if [ -n "$SSTCA" ]
+then
+    CAFILE_OPT="CAfile = $SSTCA"
+else
+    CAFILE_OPT=""
+fi
+
+if [ "${SSLMODE#VERIFY}" != "$SSLMODE" ]
+then
+    case "$SSLMODE" in
+    'VERIFY_IDENTITY')
+        VERIFY_OPT='verifyPeer = yes'
+        ;;
+    'VERIFY_CA')
+        VERIFY_OPT='verifyChain = yes'
+        ;;
+    *)
+        wsrep_log_error "Unrecognized ssl-mode option: '$SSLMODE'"
+        exit 22 # EINVAL
+    esac
+    if [ -z "$CAFILE_OPT" ]
+    then
+        wsrep_log_error "Can't have ssl-mode=$SSLMODE without CA file"
+        exit 22 # EINVAL
+    fi
+else
+    VERIFY_OPT=""
+fi
+
 STUNNEL=""
-if [ -f "$SSTKEY" ] && [ -f "$SSTCERT" ] && wsrep_check_programs stunnel
+if [ -n "$SSLMODE" -a "$SSLMODE" != 'DISABLED' ] && wsrep_check_programs stunnel
 then
-    STUNNEL="stunnel ${STUNNEL_CONF}"
+    wsrep_log_info "Using stunnel for SSL encryption: CAfile: $SSTCA, SSLMODE: $SSLMODE"
+    STUNNEL="stunnel $STUNNEL_CONF"
 fi
 
-if [ "$WSREP_SST_OPT_ROLE" = "donor" ]
+readonly SECRET_TAG="secret"
+
+if [ "$WSREP_SST_OPT_ROLE" = 'donor' ]
 then
 
 cat << EOF > "$STUNNEL_CONF"
-CApath = ${SSTCERT%/*}
+key = $SSTKEY
+cert = $SSTCERT
+${CAFILE_OPT}
 foreground = yes
 pid = $STUNNEL_PID
 debug = warning
 client = yes
 connect = ${WSREP_SST_OPT_ADDR%/*}
 TIMEOUTclose = 0
-verifyPeer = yes
+${VERIFY_OPT}
 EOF
 
     if [ $WSREP_SST_OPT_BYPASS -eq 0 ]
@@ -244,7 +311,7 @@ EOF
         rm -rf "$ERROR"
 
         # Use deltaxfer only for WAN
-        inv=$(basename $0)
+        inv=$(basename "$0")
         [ "$inv" = "wsrep_sst_rsync_wan" ] && WHOLE_FILE_OPT="" \
                                            || WHOLE_FILE_OPT="--whole-file"
 
@@ -268,49 +335,43 @@ EOF
             sleep 0.2
         done
 
-        STATE="$(cat $FLUSHED)"
+        STATE=$(cat "$FLUSHED")
         rm -rf "$FLUSHED"
 
         sync
 
-        if ! [ -z $WSREP_SST_OPT_BINLOG ]
+        if [ -n "$WSREP_SST_OPT_BINLOG" ]
         then
             # Prepare binlog files
-            OLD_PWD="$(pwd)"
-            cd $BINLOG_DIRNAME
+            cd "$BINLOG_DIRNAME"
 
-            if [ -z $WSREP_SST_OPT_BINLOG_INDEX ]
-            then
-                binlog_files_full=$(tail -n $BINLOG_N_FILES ${BINLOG_FILENAME}.index)
-            else
-                cd $BINLOG_INDEX_DIRNAME
-                binlog_files_full=$(tail -n $BINLOG_N_FILES ${BINLOG_INDEX_FILENAME})
-            fi
+            binlog_files_full=$(tail -n $BINLOG_N_FILES "${WSREP_SST_OPT_BINLOG_INDEX%.index}.index")
 
-            cd $BINLOG_DIRNAME
             binlog_files=""
             for ii in $binlog_files_full
             do
-                binlog_files="$binlog_files $(basename $ii)"
+                binlog_file=$(basename "$ii")
+                binlog_files="$binlog_files $binlog_file"
             done
 
-            if ! [ -z "$binlog_files" ]
+            if [ -n "$binlog_files" ]
             then
                 wsrep_log_info "Preparing binlog files for transfer:"
-                tar -cvf $BINLOG_TAR_FILE $binlog_files >&2
+                tar -cvf "$BINLOG_TAR_FILE" $binlog_files >&2
             fi
+
             cd "$OLD_PWD"
         fi
 
         # first, the normal directories, so that we can detect incompatible protocol
         RC=0
-        eval rsync ${STUNNEL:+--rsh="$STUNNEL"} \
+        eval rsync ${STUNNEL:+--rsh=\"$STUNNEL\"} \
               --owner --group --perms --links --specials \
               --ignore-times --inplace --dirs --delete --quiet \
               $WHOLE_FILE_OPT ${FILTER} "$WSREP_SST_OPT_DATA/" \
               rsync://$WSREP_SST_OPT_ADDR >&2 || RC=$?
 
-        if [ "$RC" -ne 0 ]; then
+        if [ $RC -ne 0 ]; then
             wsrep_log_error "rsync returned code $RC:"
 
             case $RC in
@@ -340,7 +401,7 @@ EOF
             exit 255 # unknown error
         fi
 
-        # second, we transfer InnoDB and Aria log files
+        # second, we transfer InnoDB log files
         rsync ${STUNNEL:+--rsh="$STUNNEL"} \
               --owner --group --perms --links --specials \
               --ignore-times --inplace --dirs --delete --quiet \
@@ -353,8 +414,7 @@ EOF
         fi
 
         # then, we parallelize the transfer of database directories, use . so that pathconcatenation works
-        OLD_PWD="$(pwd)"
-        cd $WSREP_SST_OPT_DATA
+        cd "$WSREP_SST_OPT_DATA"
 
         count=1
         [ "$OS" = "Linux" ] && count=$(grep -c processor /proc/cpuinfo)
@@ -376,60 +436,58 @@ EOF
         fi
 
     else # BYPASS
+
         wsrep_log_info "Bypassing state dump."
 
         # Store donor's wsrep GTID (state ID) and wsrep_gtid_domain_id
         # (separated by a space).
         STATE="$WSREP_SST_OPT_GTID $WSREP_SST_OPT_GTID_DOMAIN_ID"
+
     fi
 
     echo "continue" # now server can resume updating data
 
     echo "$STATE" > "$MAGIC_FILE"
+
+    if [ -n "$WSREP_SST_OPT_REMOTE_PSWD" ]; then
+        # Let joiner know that we know its secret
+        echo "$SECRET_TAG $WSREP_SST_OPT_REMOTE_PSWD" >> "$MAGIC_FILE"
+    fi
+
     rsync ${STUNNEL:+--rsh="$STUNNEL"} \
           --archive --quiet --checksum "$MAGIC_FILE" rsync://$WSREP_SST_OPT_ADDR
 
     echo "done $STATE"
 
-elif [ "$WSREP_SST_OPT_ROLE" = "joiner" ]
+elif [ "$WSREP_SST_OPT_ROLE" = 'joiner' ]
 then
     wsrep_check_programs lsof
 
-    touch $SST_PROGRESS_FILE
-    MYSQLD_PID=$WSREP_SST_OPT_PARENT
+    touch "$SST_PROGRESS_FILE"
+    MYSQLD_PID="$WSREP_SST_OPT_PARENT"
 
     MODULE="rsync_sst"
 
     RSYNC_PID="$WSREP_SST_OPT_DATA/$MODULE.pid"
     # give some time for lingering rsync from previous SST to complete
     check_round=0
-    while check_pid $RSYNC_PID && [ $check_round -lt 10 ]
+    while check_pid "$RSYNC_PID" && [ $check_round -lt 10 ]
     do
         wsrep_log_info "lingering rsync daemon found at startup, waiting for it to exit"
         check_round=$(( check_round + 1 ))
         sleep 1
     done
 
-    if check_pid $RSYNC_PID
+    if check_pid "$RSYNC_PID"
     then
         wsrep_log_error "rsync daemon already running."
         exit 114 # EALREADY
     fi
     rm -rf "$RSYNC_PID"
 
-    ADDR=$WSREP_SST_OPT_ADDR
-    if [ "${ADDR#\[}" != "$ADDR" ]; then
-        RSYNC_PORT=$(echo $ADDR | awk -F '\\]:' '{ print $2 }')
-        RSYNC_ADDR=$(echo $ADDR | awk -F '\\]:' '{ print $1 }')"]"
-    else
-        RSYNC_PORT=$(echo $ADDR | awk -F ':' '{ print $2 }')
-        RSYNC_ADDR=$(echo $ADDR | awk -F ':' '{ print $1 }')
-    fi
-    if [ -z "$RSYNC_PORT" ]
-    then
-        RSYNC_PORT=4444
-        ADDR="$RSYNC_ADDR:$RSYNC_PORT"
-    fi
+    ADDR="$WSREP_SST_OPT_ADDR"
+    RSYNC_PORT="$WSREP_SST_OPT_PORT"
+    RSYNC_ADDR="$WSREP_SST_OPT_HOST"
 
     trap "exit 32" HUP PIPE
     trap "exit 3"  INT TERM ABRT
@@ -437,7 +495,7 @@ then
 
     RSYNC_CONF="$WSREP_SST_OPT_DATA/$MODULE.conf"
 
-    if [ -n "${MYSQL_TMP_DIR:-}" ] ; then
+    if [ -n "${MYSQL_TMP_DIR:-}" ]; then
         SILENT="log file = $MYSQL_TMP_DIR/rsyncd.log"
     else
         SILENT=""
@@ -460,40 +518,40 @@ EOF
 
 #    rm -rf "$DATA"/ib_logfile* # we don't want old logs around
 
-    readonly RSYNC_PORT=${WSREP_SST_OPT_PORT:-4444}
     # If the IP is local listen only in it
     if is_local_ip "$RSYNC_ADDR"
     then
-      RSYNC_EXTRA_ARGS="--address $RSYNC_ADDR"
-      STUNNEL_ACCEPT="$RSYNC_ADDR:$RSYNC_PORT"
+        RSYNC_EXTRA_ARGS="--address $RSYNC_ADDR"
+        STUNNEL_ACCEPT="$RSYNC_ADDR:$RSYNC_PORT"
     else
-      # Not local, possibly a NAT, listen on all interfaces
-      RSYNC_EXTRA_ARGS=""
-      STUNNEL_ACCEPT="$RSYNC_PORT"
-      # Overwrite address with all
-      RSYNC_ADDR="*"
+        # Not local, possibly a NAT, listen on all interfaces
+        RSYNC_EXTRA_ARGS=""
+        STUNNEL_ACCEPT="$RSYNC_PORT"
+        # Overwrite address with all
+        RSYNC_ADDR="*"
     fi
 
     if [ -z "$STUNNEL" ]
     then
-      rsync --daemon --no-detach --port "$RSYNC_PORT" --config "$RSYNC_CONF" ${RSYNC_EXTRA_ARGS} &
-      RSYNC_REAL_PID=$!
+        rsync --daemon --no-detach --port "$RSYNC_PORT" --config "$RSYNC_CONF" ${RSYNC_EXTRA_ARGS} &
+        RSYNC_REAL_PID=$!
     else
-      cat << EOF > "$STUNNEL_CONF"
+        cat << EOF > "$STUNNEL_CONF"
 key = $SSTKEY
 cert = $SSTCERT
+${CAFILE_OPT}
 foreground = yes
 pid = $STUNNEL_PID
 debug = warning
 client = no
 [rsync]
 accept = $STUNNEL_ACCEPT
-exec = $(which rsync)
-execargs = rsync --server --daemon --config=$RSYNC_CONF .
+exec = $(command -v rsync)
+execargs = rsync --server --daemon --config='$RSYNC_CONF' .
 EOF
-      stunnel "$STUNNEL_CONF" &
-      RSYNC_REAL_PID=$!
-      RSYNC_PID=$STUNNEL_PID
+        stunnel "$STUNNEL_CONF" &
+        RSYNC_REAL_PID=$!
+        RSYNC_PID="$STUNNEL_PID"
     fi
 
     until check_pid_and_port "$RSYNC_PID" "$RSYNC_REAL_PID" "$RSYNC_ADDR" "$RSYNC_PORT"
@@ -501,7 +559,30 @@ EOF
         sleep 0.2
     done
 
-    echo "ready $WSREP_SST_OPT_HOST:$RSYNC_PORT/$MODULE"
+    if [ "${SSLMODE#VERIFY}" != "$SSLMODE" ]
+    then # backward-incompatible behavior
+        CN=""
+        if [ -n "$SSTCERT" ]
+        then
+            # find out my Common Name
+            get_openssl
+            if [ -z "$OPENSSL_BINARY" ]; then
+                wsrep_log_error 'openssl not found but it is required for authentication'
+                exit 42
+            fi
+            CN=$("$OPENSSL_BINARY" x509 -noout -subject -in "$SSTCERT" | \
+                 tr "," "\n" | grep "CN =" | cut -d= -f2 | sed s/^\ // | \
+                 sed s/\ %//)
+        fi
+        MY_SECRET=$(wsrep_gen_secret)
+        # Add authentication data to address
+        ADDR="$CN:$MY_SECRET@$WSREP_SST_OPT_HOST"
+    else
+        MY_SECRET="" # for check down in recv_joiner()
+        ADDR=$WSREP_SST_OPT_HOST
+    fi
+
+    echo "ready $ADDR:$RSYNC_PORT/$MODULE"
 
     # wait for SST to complete by monitoring magic file
     while [ ! -r "$MAGIC_FILE" ] && check_pid "$RSYNC_PID" && \
@@ -514,44 +595,53 @@ EOF
     then
         wsrep_log_error \
         "Parent mysqld process (PID:$MYSQLD_PID) terminated unexpectedly."
-        kill -- -"${MYSQLD_PID}"
+        kill -- -$MYSQLD_PID
         sleep 1
         exit 32
     fi
 
-    if ! [ -z $WSREP_SST_OPT_BINLOG ]
-    then
+    if [ -n "$WSREP_SST_OPT_BINLOG" ]; then
+        if [ -f "$BINLOG_TAR_FILE" ]; then
+            cd "$BINLOG_DIRNAME"
 
-        OLD_PWD="$(pwd)"
-        cd $BINLOG_DIRNAME
+            binlog_index="${WSREP_SST_OPT_BINLOG_INDEX%.index}.index"
 
-        if [ -f $BINLOG_TAR_FILE ]
-        then
             # Clean up old binlog files first
-            rm -f ${BINLOG_FILENAME}.*
+            rm -f "$BINLOG_FILENAME".[0-9]*
+            [ -f "$binlog_index" ] && rm "$binlog_index"
+
             wsrep_log_info "Extracting binlog files:"
-            tar -xvf $BINLOG_TAR_FILE >> _binlog_tmp_files_$!
+            tar -xvf "$BINLOG_TAR_FILE" >> _binlog_tmp_files_$!
             while read bin_file; do
-                if [ -z $WSREP_SST_OPT_BINLOG_INDEX ]
-                then
-                    echo ${BINLOG_DIRNAME}/${bin_file} >> ${BINLOG_FILENAME}.index
-                else
-                    echo ${BINLOG_DIRNAME}/${bin_file} >> ${BINLOG_INDEX_DIRNAME}/${BINLOG_INDEX_FILENAME}
-                fi
+                echo "$BINLOG_DIRNAME/$bin_file" >> "$binlog_index"
             done < _binlog_tmp_files_$!
             rm -f _binlog_tmp_files_$!
-        fi
-        cd "$OLD_PWD"
 
+            cd "$OLD_PWD"
+        fi
     fi
+
     if [ -r "$MAGIC_FILE" ]
     then
+        # check donor supplied secret
+        SECRET=$(grep "$SECRET_TAG " "$MAGIC_FILE" 2>/dev/null | cut -d ' ' -f 2)
+        if [ "$SECRET" != "$MY_SECRET" ]; then
+            wsrep_log_error "Donor does not know my secret!"
+            wsrep_log_info "Donor:'$SECRET', my:'$MY_SECRET'"
+            exit 32
+        fi
+
+        # remove secret from magic file
+        grep -v "$SECRET_TAG " "$MAGIC_FILE" > "$MAGIC_FILE.new"
+
+        mv "$MAGIC_FILE.new" "$MAGIC_FILE"
         # UUID:seqno & wsrep_gtid_domain_id is received here.
         cat "$MAGIC_FILE" # Output : UUID:seqno wsrep_gtid_domain_id
     else
         # this message should cause joiner to abort
         echo "rsync process ended without creating '$MAGIC_FILE'"
     fi
+
     wsrep_cleanup_progress_file
 #    cleanup_joiner
 else
@@ -559,6 +649,6 @@ else
     exit 22 # EINVAL
 fi
 
-rm -f $BINLOG_TAR_FILE || :
+rm -f "$BINLOG_TAR_FILE" || :
 
 exit 0