* See accompanying file LICENSE.txt or copy at
* https://opensource.org/licenses/MIT
***/
+
#ifndef SHA1DC_SHA1_H
#define SHA1DC_SHA1_H
extern "C" {
#endif
-/* uses SHA-1 message expansion to expand the first 16 words of W[] to 80 words */
-/* void sha1_message_expansion(uint32_t W[80]); */
-
-/* sha-1 compression function; first version takes a message block pre-parsed as 16 32-bit integers, second version takes an already expanded message) */
-/* void sha1_compression(uint32_t ihv[5], const uint32_t m[16]);
-void sha1_compression_W(uint32_t ihv[5], const uint32_t W[80]); */
+#ifndef SHA1DC_NO_STANDARD_INCLUDES
+#include <stdint.h>
+#endif
-/* same as sha1_compression_W, but additionally store intermediate states */
+/* 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
+// 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*);
-/* table of sha1_recompression_step_0, ... , sha1_recompression_step_79 */
-/* extern sha1_recompression_type sha1_recompression_step[80];*/
-
-/* a callback function type that can be set to be called when a collision block has been found: */
+/* 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 */
+/* The SHA-1 context. */
typedef struct {
uint64_t total;
uint32_t ihv[5];
uint32_t states[80][5];
} SHA1_CTX;
-/* initialize SHA-1 context */
+/* 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 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
+ 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 */
+/*
+ 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 */
+/*
+ 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 */
/* returns: 0 = no collision detected, otherwise = collision found => warn user for active attack */
int SHA1DCFinal(unsigned char[20], SHA1_CTX*);
-/*
- * Same as SHA1DCFinal, but convert collision attack case into a verbose die().
- */
-void git_SHA1DCFinal(unsigned char [20], SHA1_CTX *);
-
-/*
- * Same as SHA1DCUpdate, but adjust types to match git's usual interface.
- */
-void git_SHA1DCUpdate(SHA1_CTX *ctx, const void *data, unsigned long len);
-
-#define platform_SHA_CTX SHA1_CTX
-#define platform_SHA1_Init SHA1DCInit
-#define platform_SHA1_Update git_SHA1DCUpdate
-#define platform_SHA1_Final git_SHA1DCFinal
-
#if defined(__cplusplus)
}
#endif
-#endif /* SHA1DC_SHA1_H */
+#ifdef SHA1DC_CUSTOM_TRAILING_INCLUDE_SHA1_H
+#include SHA1DC_CUSTOM_TRAILING_INCLUDE_SHA1_H
+#endif
+
+#endif
projects / thirdparty / git.git / blobdiff