1 /*
2  * Copyright (C) the libgit2 contributors. All rights reserved.
3  *
4  * This file is part of libgit2, distributed under the GNU GPL v2 with
5  * a Linking Exception. For full terms see the included COPYING file.
6  */
7 
8 #ifndef INCLUDE_hash_hash_collisiondetect_h__
9 #define INCLUDE_hash_hash_collisiondetect_h__
10 
11 #include "hash.h"
12 #include "sha1dc/sha1.h"
13 
14 struct git_hash_ctx {
15 	SHA1_CTX c;
16 };
17 
18 #define git_hash_global_init() 0
19 #define git_hash_ctx_init(ctx) git_hash_init(ctx)
20 #define git_hash_ctx_cleanup(ctx)
21 
git_hash_init(git_hash_ctx * ctx)22 GIT_INLINE(int) git_hash_init(git_hash_ctx *ctx)
23 {
24 	assert(ctx);
25 	SHA1DCInit(&ctx->c);
26 	return 0;
27 }
28 
git_hash_update(git_hash_ctx * ctx,const void * data,size_t len)29 GIT_INLINE(int) git_hash_update(git_hash_ctx *ctx, const void *data, size_t len)
30 {
31 	assert(ctx);
32 	SHA1DCUpdate(&ctx->c, data, len);
33 	return 0;
34 }
35 
git_hash_final(git_oid * out,git_hash_ctx * ctx)36 GIT_INLINE(int) git_hash_final(git_oid *out, git_hash_ctx *ctx)
37 {
38 	assert(ctx);
39 	if (SHA1DCFinal(out->id, &ctx->c)) {
40 		giterr_set(GITERR_SHA1, "SHA1 collision attack detected");
41 		return -1;
42 	}
43 
44 	return 0;
45 }
46 
47 #endif
48