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Diffstat (limited to '')
| -rw-r--r-- | sha1dc/sha1.h | 110 |
1 files changed, 110 insertions, 0 deletions
diff --git a/sha1dc/sha1.h b/sha1dc/sha1.h new file mode 100644 index 0000000..1e4e94b --- /dev/null +++ b/sha1dc/sha1.h @@ -0,0 +1,110 @@ +/*** +* Copyright 2017 Marc Stevens <marc@marc-stevens.nl>, Dan Shumow <danshu@microsoft.com> +* Distributed under the MIT Software License. +* See accompanying file LICENSE.txt or copy at +* https://opensource.org/licenses/MIT +***/ + +#ifndef SHA1DC_SHA1_H +#define SHA1DC_SHA1_H + +#if defined(__cplusplus) +extern "C" { +#endif + +#ifndef SHA1DC_NO_STANDARD_INCLUDES +#include <stdint.h> +#endif + +/* sha-1 compression function that takes an already expanded message, and additionally store intermediate states */ +/* only stores states ii (the state between step ii-1 and step ii) when DOSTORESTATEii is defined in ubc_check.h */ +void sha1_compression_states(uint32_t[5], const uint32_t[16], uint32_t[80], uint32_t[80][5]); + +/* +// Function type for sha1_recompression_step_T (uint32_t ihvin[5], uint32_t ihvout[5], const uint32_t me2[80], const uint32_t state[5]). +// Where 0 <= T < 80 +// me2 is an expanded message (the expansion of an original message block XOR'ed with a disturbance vector's message block difference.) +// state is the internal state (a,b,c,d,e) before step T of the SHA-1 compression function while processing the original message block. +// The function will return: +// ihvin: The reconstructed input chaining value. +// ihvout: The reconstructed output chaining value. +*/ +typedef void(*sha1_recompression_type)(uint32_t*, uint32_t*, const uint32_t*, const uint32_t*); + +/* A callback function type that can be set to be called when a collision block has been found: */ +/* void collision_block_callback(uint64_t byteoffset, const uint32_t ihvin1[5], const uint32_t ihvin2[5], const uint32_t m1[80], const uint32_t m2[80]) */ +typedef void(*collision_block_callback)(uint64_t, const uint32_t*, const uint32_t*, const uint32_t*, const uint32_t*); + +/* The SHA-1 context. */ +typedef struct { + uint64_t total; + uint32_t ihv[5]; + unsigned char buffer[64]; + int found_collision; + int safe_hash; + int detect_coll; + int ubc_check; + int reduced_round_coll; + collision_block_callback callback; + + uint32_t ihv1[5]; + uint32_t ihv2[5]; + uint32_t m1[80]; + uint32_t m2[80]; + uint32_t states[80][5]; +} SHA1_CTX; + +/* Initialize SHA-1 context. */ +void SHA1DCInit(SHA1_CTX*); + +/* + Function to enable safe SHA-1 hashing: + Collision attacks are thwarted by hashing a detected near-collision block 3 times. + Think of it as extending SHA-1 from 80-steps to 240-steps for such blocks: + The best collision attacks against SHA-1 have complexity about 2^60, + thus for 240-steps an immediate lower-bound for the best cryptanalytic attacks would be 2^180. + An attacker would be better off using a generic birthday search of complexity 2^80. + + Enabling safe SHA-1 hashing will result in the correct SHA-1 hash for messages where no collision attack was detected, + but it will result in a different SHA-1 hash for messages where a collision attack was detected. + This will automatically invalidate SHA-1 based digital signature forgeries. + Enabled by default. +*/ +void SHA1DCSetSafeHash(SHA1_CTX*, int); + +/* + Function to disable or enable the use of Unavoidable Bitconditions (provides a significant speed up). + Enabled by default + */ +void SHA1DCSetUseUBC(SHA1_CTX*, int); + +/* + Function to disable or enable the use of Collision Detection. + Enabled by default. + */ +void SHA1DCSetUseDetectColl(SHA1_CTX*, int); + +/* function to disable or enable the detection of reduced-round SHA-1 collisions */ +/* disabled by default */ +void SHA1DCSetDetectReducedRoundCollision(SHA1_CTX*, int); + +/* function to set a callback function, pass NULL to disable */ +/* by default no callback set */ +void SHA1DCSetCallback(SHA1_CTX*, collision_block_callback); + +/* update SHA-1 context with buffer contents */ +void SHA1DCUpdate(SHA1_CTX*, const char*, size_t); + +/* obtain SHA-1 hash from SHA-1 context */ +/* returns: 0 = no collision detected, otherwise = collision found => warn user for active attack */ +int SHA1DCFinal(unsigned char[20], SHA1_CTX*); + +#if defined(__cplusplus) +} +#endif + +#ifdef SHA1DC_CUSTOM_TRAILING_INCLUDE_SHA1_H +#include SHA1DC_CUSTOM_TRAILING_INCLUDE_SHA1_H +#endif + +#endif |