http://hg.python.org/cpython/rev/4b5467d997f1
changeset: 83836:4b5467d997f1
branch: 3.3
parent: 83833:c430bea30457
user: Serhiy Storchaka <storchaka at gmail.com>
date: Sun May 19 11:41:15 2013 +0300
summary:
Issue #17812: Fixed quadratic complexity of base64.b32encode().
files:
Lib/base64.py | 12 ++++++------
Misc/NEWS | 2 ++
2 files changed, 8 insertions(+), 6 deletions(-)
diff --git a/Lib/base64.py b/Lib/base64.py
--- a/Lib/base64.py
+++ b/Lib/base64.py
@@ -166,7 +166,7 @@
if leftover:
s = s + bytes(5 - leftover) # Don't use += !
quanta += 1
- encoded = bytes()
+ encoded = bytearray()
for i in range(quanta):
# c1 and c2 are 16 bits wide, c3 is 8 bits wide. The intent of this
# code is to process the 40 bits in units of 5 bits. So we take the 1
@@ -187,14 +187,14 @@
])
# Adjust for any leftover partial quanta
if leftover == 1:
- return encoded[:-6] + b'======'
+ encoded[-6:] = b'======'
elif leftover == 2:
- return encoded[:-4] + b'===='
+ encoded[-4:] = b'===='
elif leftover == 3:
- return encoded[:-3] + b'==='
+ encoded[-3:] = b'==='
elif leftover == 4:
- return encoded[:-1] + b'='
- return encoded
+ encoded[-1:] = b'='
+ return bytes(encoded)
def b32decode(s, casefold=False, map01=None):
diff --git a/Misc/NEWS b/Misc/NEWS
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -24,6 +24,8 @@
Library
-------
+- Issue #17812: Fixed quadratic complexity of base64.b32encode().
+
- Issue #17980: Fix possible abuse of ssl.match_hostname() for denial of
service using certificates with many wildcards (CVE-2013-2099).
--
Repository URL: http://hg.python.org/cpython