thodg/libgit2/src/util/hash.c

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• Hash : b900981c
  Author :
  Date : 2021-12-12T14:25:25
  

  sha: add sha256 algorithm Add support for a SHA256 hash algorithm, and add the "builtin" SHA256 hash engine (from RFC 6234).

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• src/util/hash.c

• /*
   * 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.
   */
  
  #include "hash.h"
  
  int git_hash_global_init(void)
  {
  	if (git_hash_sha1_global_init() < 0 ||
  	    git_hash_sha256_global_init() < 0)
  		return -1;
  
  	return 0;
  }
  
  int git_hash_ctx_init(git_hash_ctx *ctx, git_hash_algorithm_t algorithm)
  {
  	int error;
  
  	switch (algorithm) {
  	case GIT_HASH_ALGORITHM_SHA1:
  		error = git_hash_sha1_ctx_init(&ctx->ctx.sha1);
  		break;
  	case GIT_HASH_ALGORITHM_SHA256:
  		error = git_hash_sha256_ctx_init(&ctx->ctx.sha256);
  		break;
  	default:
  		git_error_set(GIT_ERROR_INTERNAL, "unknown hash algorithm");
  		error = -1;
  	}
  
  	ctx->algorithm = algorithm;
  	return error;
  }
  
  void git_hash_ctx_cleanup(git_hash_ctx *ctx)
  {
  	switch (ctx->algorithm) {
  	case GIT_HASH_ALGORITHM_SHA1:
  		git_hash_sha1_ctx_cleanup(&ctx->ctx.sha1);
  		return;
  	case GIT_HASH_ALGORITHM_SHA256:
  		git_hash_sha256_ctx_cleanup(&ctx->ctx.sha256);
  		return;
  	default:
  		/* unreachable */ ;
  	}
  }
  
  int git_hash_init(git_hash_ctx *ctx)
  {
  	switch (ctx->algorithm) {
  	case GIT_HASH_ALGORITHM_SHA1:
  		return git_hash_sha1_init(&ctx->ctx.sha1);
  	case GIT_HASH_ALGORITHM_SHA256:
  		return git_hash_sha256_init(&ctx->ctx.sha256);
  	default:
  		/* unreachable */ ;
  	}
  
  	git_error_set(GIT_ERROR_INTERNAL, "unknown hash algorithm");
  	return -1;
  }
  
  int git_hash_update(git_hash_ctx *ctx, const void *data, size_t len)
  {
  	switch (ctx->algorithm) {
  	case GIT_HASH_ALGORITHM_SHA1:
  		return git_hash_sha1_update(&ctx->ctx.sha1, data, len);
  	case GIT_HASH_ALGORITHM_SHA256:
  		return git_hash_sha256_update(&ctx->ctx.sha256, data, len);
  	default:
  		/* unreachable */ ;
  	}
  
  	git_error_set(GIT_ERROR_INTERNAL, "unknown hash algorithm");
  	return -1;
  }
  
  int git_hash_final(unsigned char *out, git_hash_ctx *ctx)
  {
  	switch (ctx->algorithm) {
  	case GIT_HASH_ALGORITHM_SHA1:
  		return git_hash_sha1_final(out, &ctx->ctx.sha1);
  	case GIT_HASH_ALGORITHM_SHA256:
  		return git_hash_sha256_final(out, &ctx->ctx.sha256);
  	default:
  		/* unreachable */ ;
  	}
  
  	git_error_set(GIT_ERROR_INTERNAL, "unknown hash algorithm");
  	return -1;
  }
  
  int git_hash_buf(
  	unsigned char *out,
  	const void *data,
  	size_t len,
  	git_hash_algorithm_t algorithm)
  {
  	git_hash_ctx ctx;
  	int error = 0;
  
  	if (git_hash_ctx_init(&ctx, algorithm) < 0)
  		return -1;
  
  	if ((error = git_hash_update(&ctx, data, len)) >= 0)
  		error = git_hash_final(out, &ctx);
  
  	git_hash_ctx_cleanup(&ctx);
  
  	return error;
  }
  
  int git_hash_vec(
  	unsigned char *out,
  	git_str_vec *vec,
  	size_t n,
  	git_hash_algorithm_t algorithm)
  {
  	git_hash_ctx ctx;
  	size_t i;
  	int error = 0;
  
  	if (git_hash_ctx_init(&ctx, algorithm) < 0)
  		return -1;
  
  	for (i = 0; i < n; i++) {
  		if ((error = git_hash_update(&ctx, vec[i].data, vec[i].len)) < 0)
  			goto done;
  	}
  
  	error = git_hash_final(out, &ctx);
  
  done:
  	git_hash_ctx_cleanup(&ctx);
  
  	return error;
  }
  
  int git_hash_fmt(char *out, unsigned char *hash, size_t hash_len)
  {
  	static char hex[] = "0123456789abcdef";
  	char *str = out;
  	size_t i;
  
  	for (i = 0; i < hash_len; i++) {
  		*str++ = hex[hash[i] >> 4];
  		*str++ = hex[hash[i] & 0x0f];
  	}
  
  	*str++ = '\0';
  
  	return 0;
  }
  

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