Fixed MDEV-4013: Password length in replication setup

Give error for wrong parameters to CHANGE MASTER
Extend MASTER_PASSWORD and MASTER_HOST lengths


mysql-test/suite/rpl/r/rpl_password_boundaries.result:
  Test length of MASTER_PASSWORD, MASTER_HOST and MASTER_USER
mysql-test/suite/rpl/r/rpl_semi_sync.result:
  Use different password than user name for better test coverage
mysql-test/suite/rpl/t/rpl_password_boundaries.test:
  Test length of MASTER_PASSWORD, MASTER_HOST and MASTER_USER
mysql-test/suite/rpl/t/rpl_semi_sync.test:
  Use different password than user name for better test coverage
sql/rpl_mi.h:
  Extend MASTER_PASSWORD and MASTER_HOST lengths
sql/sql_repl.cc:
  Give error for wrong parameters to CHANGE MASTER
sql/sql_repl.h:
  Extend MASTER_PASSWORD and MASTER_HOST lengths

3 files changed, 41 insertions, 11 deletions

diff --git a/sql/rpl_mi.h b/sql/rpl_mi.h
index a885576ef1c..64525f81603 100644
--- a/sql/rpl_mi.h
+++ b/sql/rpl_mi.h
@@ -66,9 +66,9 @@ class Master_info : public Slave_reporting_capability
 
   /* the variables below are needed because we can change masters on the fly */
   char master_log_name[FN_REFLEN];
-  char host[HOSTNAME_LENGTH+1];
-  char user[USERNAME_LENGTH+1];
-  char password[MAX_PASSWORD_LENGTH+1];
+  char host[HOSTNAME_LENGTH*SYSTEM_CHARSET_MBMAXLEN+1];
+  char user[USERNAME_LENGTH*+1];
+  char password[MAX_PASSWORD_LENGTH*SYSTEM_CHARSET_MBMAXLEN+1];
   bool ssl; // enables use of SSL connection if true
   char ssl_ca[FN_REFLEN], ssl_capath[FN_REFLEN], ssl_cert[FN_REFLEN];
   char ssl_cipher[FN_REFLEN], ssl_key[FN_REFLEN];
diff --git a/sql/sql_repl.cc b/sql/sql_repl.cc
index 53ac103dda1..631825f0527 100644
--- a/sql/sql_repl.cc
+++ b/sql/sql_repl.cc
@@ -1541,6 +1541,31 @@ void kill_zombie_dump_threads(uint32 slave_server_id)
   }
 }
 
+/**
+   Get value for a string parameter with error checking
+
+   Note that in case of error the original string should not be updated!
+
+   @ret 0 ok
+   @ret 1 error
+*/
+
+static bool get_string_parameter(char *to, const char *from, size_t length,
+                                 const char *name)
+{
+  if (from)                                     // Empty paramaters allowed
+  {
+    size_t from_length;
+    if ((from_length= strlen(from)) > length)
+    {
+      my_error(ER_WRONG_STRING_LENGTH, MYF(0), from, name, (int) length);
+      return 1;
+    }
+    memcpy(to, from, from_length+1);
+  }
+  return 0;
+}
+
 
 /**
   Execute a CHANGE MASTER statement.
@@ -1633,12 +1658,17 @@ bool change_master(THD* thd, Master_info* mi)
   }
   DBUG_PRINT("info", ("master_log_pos: %lu", (ulong) mi->master_log_pos));
 
-  if (lex_mi->host)
-    strmake(mi->host, lex_mi->host, sizeof(mi->host)-1);
-  if (lex_mi->user)
-    strmake(mi->user, lex_mi->user, sizeof(mi->user)-1);
-  if (lex_mi->password)
-    strmake(mi->password, lex_mi->password, sizeof(mi->password)-1);
+  if (get_string_parameter(mi->host, lex_mi->host, sizeof(mi->host)-1,
+                           "MASTER_HOST") ||
+      get_string_parameter(mi->user, lex_mi->user, sizeof(mi->user)-1,
+                           "MASTER_USER") ||
+      get_string_parameter(mi->password, lex_mi->password,
+                           sizeof(mi->password)-1, "MASTER_PASSWORD"))
+  {
+    ret= TRUE;
+    goto err;
+  }
+
   if (lex_mi->port)
     mi->port = lex_mi->port;
   if (lex_mi->connect_retry)
diff --git a/sql/sql_repl.h b/sql/sql_repl.h
index 7dc58c47d52..c5a0b31388e 100644
--- a/sql/sql_repl.h
+++ b/sql/sql_repl.h
@@ -25,9 +25,9 @@ typedef struct st_slave_info
 {
   uint32 server_id;
   uint32 rpl_recovery_rank, master_id;
-  char host[HOSTNAME_LENGTH+1];
+  char host[HOSTNAME_LENGTH*SYSTEM_CHARSET_MBMAXLEN+1];
   char user[USERNAME_LENGTH+1];
-  char password[MAX_PASSWORD_LENGTH+1];
+  char password[MAX_PASSWORD_LENGTH*SYSTEM_CHARSET_MBMAXLEN+1];
   uint16 port;
   THD* thd;
 } SLAVE_INFO;