Fix error in CT compare, add negative tests for TLS pad checks#385
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ColtonWilley wants to merge 1 commit intowolfSSL:masterfrom
Open
Fix error in CT compare, add negative tests for TLS pad checks#385ColtonWilley wants to merge 1 commit intowolfSSL:masterfrom
ColtonWilley wants to merge 1 commit intowolfSSL:masterfrom
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padelsbach
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Apr 5, 2026
| byte wp_ct_byte_mask_ne(byte a, byte b) | ||
| { | ||
| return (((int32_t)b - a) >> 31) & (((int32_t)a - b) >> 31); | ||
| return (((int32_t)b - a) >> 31) | (((int32_t)a - b) >> 31); |
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This is potentially a more robust fix, with less bit math:
return ~wp_ct_byte_mask_eq(a, b);
| /** | ||
| * Constant time, set mask when first value is not equal to second. | ||
| * | ||
| * @param [in] a First valuue. |
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Semi-related nit: typo here in "valuue". Also on line 1155.
| * Encrypt block-aligned plaintext (produces a full padding block), corrupt a | ||
| * ciphertext byte so the padding block is garbled, verify DecryptFinal rejects. | ||
| */ | ||
| int test_des3_cbc_bad_pad(void *data) |
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I see that DES3 CBC is the only path for testing wp_ct_byte_mask_ne, currently. So this is a good add, but...
Can we add some test vectors for wp_ct_* functions? There seem to be no direct tests of these today. Just to ensure coverage.
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