PKCS#1 2.0: Implementation of MGF1 #89
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@sybrenstuvel any feedback about this? |
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Hey dude! Sorry, had a crazy busy period. I'm looking forward to diving into your code this weekend ;-) |
rsa/pkcs1_v2.py
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| # If l > 2^32(hLen), output "mask too long" and stop. | ||
| if length > (2**32 * hash_length): | ||
| raise OverflowError |
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Add a message to the OverflowError with description of the error.
rsa/pkcs1_v2.py
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| :param hasher: hash function (hLen denotes the length in octets of the hash | ||
| function output) | ||
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| :return: mask, an octet string of length `length` |
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Add :rtype: bytes so that it's clear bytes are returned. This also helps IDEs that parse the docstring to perform autocompletion and linting.
rsa/pkcs1_v2.py
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| c = transform.int2bytes(counter, fill_size=4) | ||
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| # Concatenate the hash of the `seed` and C to the octet string `output` | ||
| output += pkcs1._hash(seed + c, method_name=hasher) |
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This is a bad idea. output is stored using a fixed-length array, and concatenating to that will cause a copy to be made. Instead, append each output of pkcs1._hash() to a list, then return b''.join(thelist).
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Good catch! Moved the whole thing to a joined generator solution
rsa/pkcs1_v2.py
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| the output of the mask generation function, which in turn relies on the | ||
| random nature of the underlying hash. | ||
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| :param seed: seed from which mask is generated, an octet string |
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Document parameter types using :type:.
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I found a compact syntax for this! http://www.sphinx-doc.org/en/stable/domains.html#info-field-lists
| """Tests PKCS #1 version 2 functionality. | ||
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| Most of the mocked values come from the test vectors found at: | ||
| http://www.itomorrowmag.com/emc-plus/rsa-labs/standards-initiatives/pkcs-rsa-cryptography-standard.htm |
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@sybrenstuvel ready to review! |
Implementation of the Mask Generation Function `MGF1` used in the OAEP encoding step. For more information, the MGF1 specification is at https://tools.ietf.org/html/rfc2437#section-10.2.1
Implementation of the Mask Generation Function
MGF1used in the OAEP encoding step.For more information, the MGF1 specification is at https://tools.ietf.org/html/rfc2437#section-10.2.1