1 files changed, 158 insertions, 0 deletions
diff --git a/src/util/hash.c b/src/util/hash.c
new file mode 100644
index 000000000..ff900cea7
--- /dev/null
+++ b/src/util/hash.c
@@ -0,0 +1,158 @@
+/*
+ * 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;
+}