thodg/libgit2/src/hash/hash_collisiondetect.h

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• Hash : 2dfd1294
  Author :
  Date : 2017-02-24T13:34:01
  

  hash: include sha1collisiondetection Include the SHA1 collision attack detection library from https://github.com/cr-marcstevens/sha1collisiondetection

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• src/hash/hash_collisiondetect.h

• /*
   * Copyright (C) the libgit2 contributors. All rights reserved.
   *
   * This file is part of libgit2, distributed under the GNU GPL v2 with
   * a Linking Exception. For full terms see the included COPYING file.
   */
  
  #ifndef INCLUDE_hash_collisiondetect_h__
  #define INCLUDE_hash_collisiondetect_h__
  
  #include "hash.h"
  #include "sha1dc/sha1.h"
  
  struct git_hash_ctx {
  	SHA1_CTX c;
  };
  
  #define git_hash_global_init() 0
  #define git_hash_ctx_init(ctx) git_hash_init(ctx)
  #define git_hash_ctx_cleanup(ctx)
  
  GIT_INLINE(int) git_hash_init(git_hash_ctx *ctx)
  {
  	assert(ctx);
  	SHA1DCInit(&ctx->c);
  	return 0;
  }
  
  GIT_INLINE(int) git_hash_update(git_hash_ctx *ctx, const void *data, size_t len)
  {
      const char *p = data;
  
  	assert(ctx);
  
  	/* We expect a size_t, but sha1dc only takes an int */
  	while (len > INT_MAX) {
  		SHA1DCUpdate(&ctx->c, p, INT_MAX);
  		p += INT_MAX;
  		len -= INT_MAX;
  	}
  
  	SHA1DCUpdate(&ctx->c, p, len);
  	return 0;
  }
  
  GIT_INLINE(int) git_hash_final(git_oid *out, git_hash_ctx *ctx)
  {
  	assert(ctx);
  	if (SHA1DCFinal(out->id, &ctx->c)) {
  		giterr_set(GITERR_SHA1, "SHA1 collision attack detected");
  		return -1;
  	}
  
  	return 0;
  }
  
  #endif /* INCLUDE_hash_collisiondetect_h__ */
  

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