Reject invalid Base64 characters in b64.b64decode() #263
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viccie30 wants to merge 2 commits intocertbot:mainfrom
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Reject invalid Base64 characters in b64.b64decode() #263viccie30 wants to merge 2 commits intocertbot:mainfrom
viccie30 wants to merge 2 commits intocertbot:mainfrom
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Python's base64.urlsafe_b64decode() has 2 footguns. It silently ignores invalid Base64 characters. It also accepts and decodes the non-urlsafe counterparts of '-' and '_'.
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Python's
base64.urlsafe_b64decode()has 2 footguns. It silently ignores invalid Base64 characters. It also accepts and decodes the non-urlsafe counterparts of '-' and '_'.According to RFC7515 the Base64 encoding must have "all trailing '=' characters omitted and [no] inclusion of any line breaks, whitespace, or other additional characters."
The test code wasn't run, because it was missing the base class declaration of the test classes. Once I added that and ran the tests, it specifically tests that trailing '=' characters are allowed, in contradiction to the RFC.
The check I added does allow trailing '=' characters, but I don't know if this is wanted.