RSA PKCS#1 v1.5 signature scheme verification incompatibility issue #10
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Owner
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Seems great, could you add a test vector for this use case ? Do not try to add to the existing one extracted from PKCS#1 specification, just add it directly in the test files. |
Author
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I might not be able to do this at the moment but may try this later. |
Closed
bmurray7
reviewed
Jan 22, 2022
| except ValueError: | ||
| raise exceptions.RSAModulusTooShort | ||
| return primitives.constant_time_cmp(em, em_prime) | ||
| return primitives.constant_time_cmp(em, em_prime) or primitives.constant_time_cmp(em, em_prime_imp) |
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Is this still constant time?
In an or statement, Python only evaluates the second condition if the first condition evaluates to True. See the Python specification for Boolean operations..
Owner
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You are right. But don't expect this lib to give you real constant time even with this change. It's a toy implementation, if you need a really hardened implementation of RSA, there are a lot around written in C or ASM.
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Added support for implicit NULL parameter case in pkcs1 signature verification