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| author | maxim-yurchuk <maxim-yurchuk@yandex-team.com> | 2024-10-09 12:29:46 +0300 |
|---|---|---|
| committer | maxim-yurchuk <maxim-yurchuk@yandex-team.com> | 2024-10-09 13:14:22 +0300 |
| commit | 9731d8a4bb7ee2cc8554eaf133bb85498a4c7d80 (patch) | |
| tree | a8fb3181d5947c0d78cf402aa56e686130179049 /contrib/python/cryptography/py3/_cffi_src/hazmat_src | |
| parent | a44b779cd359f06c3ebbef4ec98c6b38609d9d85 (diff) | |
| download | ydb-9731d8a4bb7ee2cc8554eaf133bb85498a4c7d80.tar.gz | |
publishFullContrib: true for ydb
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commit_hash:c82a80ac4594723cebf2c7387dec9c60217f603e
Diffstat (limited to 'contrib/python/cryptography/py3/_cffi_src/hazmat_src')
| -rw-r--r-- | contrib/python/cryptography/py3/_cffi_src/hazmat_src/padding.c | 65 | ||||
| -rw-r--r-- | contrib/python/cryptography/py3/_cffi_src/hazmat_src/padding.h | 6 |
2 files changed, 71 insertions, 0 deletions
diff --git a/contrib/python/cryptography/py3/_cffi_src/hazmat_src/padding.c b/contrib/python/cryptography/py3/_cffi_src/hazmat_src/padding.c new file mode 100644 index 0000000000..a6e05dee1e --- /dev/null +++ b/contrib/python/cryptography/py3/_cffi_src/hazmat_src/padding.c @@ -0,0 +1,65 @@ +// This file is dual licensed under the terms of the Apache License, Version +// 2.0, and the BSD License. See the LICENSE file in the root of this +// repository for complete details. + +/* Returns the value of the input with the most-significant-bit copied to all + of the bits. */ +static uint16_t Cryptography_DUPLICATE_MSB_TO_ALL(uint16_t a) { + return (1 - (a >> (sizeof(uint16_t) * 8 - 1))) - 1; +} + +/* This returns 0xFFFF if a < b else 0x0000, but does so in a constant time + fashion */ +static uint16_t Cryptography_constant_time_lt(uint16_t a, uint16_t b) { + a -= b; + return Cryptography_DUPLICATE_MSB_TO_ALL(a); +} + +uint8_t Cryptography_check_pkcs7_padding(const uint8_t *data, + uint16_t block_len) { + uint16_t i; + uint16_t pad_size = data[block_len - 1]; + uint16_t mismatch = 0; + for (i = 0; i < block_len; i++) { + unsigned int mask = Cryptography_constant_time_lt(i, pad_size); + uint16_t b = data[block_len - 1 - i]; + mismatch |= (mask & (pad_size ^ b)); + } + + /* Check to make sure the pad_size was within the valid range. */ + mismatch |= ~Cryptography_constant_time_lt(0, pad_size); + mismatch |= Cryptography_constant_time_lt(block_len, pad_size); + + /* Make sure any bits set are copied to the lowest bit */ + mismatch |= mismatch >> 8; + mismatch |= mismatch >> 4; + mismatch |= mismatch >> 2; + mismatch |= mismatch >> 1; + /* Now check the low bit to see if it's set */ + return (mismatch & 1) == 0; +} + +uint8_t Cryptography_check_ansix923_padding(const uint8_t *data, + uint16_t block_len) { + uint16_t i; + uint16_t pad_size = data[block_len - 1]; + uint16_t mismatch = 0; + /* Skip the first one with the pad size */ + for (i = 1; i < block_len; i++) { + unsigned int mask = Cryptography_constant_time_lt(i, pad_size); + uint16_t b = data[block_len - 1 - i]; + mismatch |= (mask & b); + } + + /* Check to make sure the pad_size was within the valid range. */ + mismatch |= ~Cryptography_constant_time_lt(0, pad_size); + mismatch |= Cryptography_constant_time_lt(block_len, pad_size); + + /* Make sure any bits set are copied to the lowest bit */ + mismatch |= mismatch >> 8; + mismatch |= mismatch >> 4; + mismatch |= mismatch >> 2; + mismatch |= mismatch >> 1; + /* Now check the low bit to see if it's set */ + return (mismatch & 1) == 0; +} diff --git a/contrib/python/cryptography/py3/_cffi_src/hazmat_src/padding.h b/contrib/python/cryptography/py3/_cffi_src/hazmat_src/padding.h new file mode 100644 index 0000000000..fb023c1711 --- /dev/null +++ b/contrib/python/cryptography/py3/_cffi_src/hazmat_src/padding.h @@ -0,0 +1,6 @@ +// This file is dual licensed under the terms of the Apache License, Version +// 2.0, and the BSD License. See the LICENSE file in the root of this +// repository for complete details. + +uint8_t Cryptography_check_pkcs7_padding(const uint8_t *, uint8_t); +uint8_t Cryptography_check_ansix923_padding(const uint8_t *, uint8_t); |