md5_crypt / sha2-crypt cleanup

* tried to clarify documentation & alg for builtin md5_crypt / sha2-crypt backends
* replaced regex parser in sha2-crypt with index-based one - less redundant, and should be faster.

2 files changed, 10 insertions, 1 deletions

diff --git a/passlib/utils/__init__.py b/passlib/utils/__init__.py
index e8e5b27..785afe0 100644
--- a/passlib/utils/__init__.py
+++ b/passlib/utils/__init__.py
@@ -481,6 +481,15 @@ def int_to_bytes(value, count):
         for s in irange(8*count-8,-8,-8)
     )
 
+def repeat_bytes(source, size):
+    "repeat or truncate <source> bytes, so it has length <size>"
+    cur = len(source)
+    if size <= cur:
+        return source[:size]
+    else:
+        mult = (size+cur-1)//cur
+        return (source*mult)[:size]
+
 #=============================================================================
 # encoding helpers
 #=============================================================================
diff --git a/passlib/utils/handlers.py b/passlib/utils/handlers.py
index abd975d..ea8674c 100644
--- a/passlib/utils/handlers.py
+++ b/passlib/utils/handlers.py
@@ -113,7 +113,7 @@ def parse_mc3(hash, prefix, sep=_UDOLLAR, rounds_base=10,
               default_rounds=None, handler=None):
     """parse hash using 3-part modular crypt format.
 
-    this expects a hash of the format :samp:`{prefix}[{rounds}$]{salt}[${checksum}]`,
+    this expects a hash of the format :samp:`{prefix}[{rounds}]${salt}[${checksum}]`,
     such as sha1_crypt, and parses it into rounds / salt / checksum portions.
     tries to convert the rounds to an integer,
     and throws error if it has zero-padding.