GCC Code Coverage Report
Directory: ./ Exec Total Coverage
File: usr.bin/ssh/lib/../hmac.c Lines: 0 50 0.0 %
Date: 2017-11-13 Branches: 0 40 0.0 %

Line Branch Exec Source
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/* $OpenBSD: hmac.c,v 1.12 2015/03/24 20:03:44 markus Exp $ */
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/*
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 * Copyright (c) 2014 Markus Friedl.  All rights reserved.
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 *
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 * Permission to use, copy, modify, and distribute this software for any
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 * purpose with or without fee is hereby granted, provided that the above
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 * copyright notice and this permission notice appear in all copies.
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 *
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 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
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 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
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 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
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 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
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 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
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 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
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 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
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 */
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#include <sys/types.h>
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#include <string.h>
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#include "sshbuf.h"
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#include "digest.h"
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#include "hmac.h"
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struct ssh_hmac_ctx {
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	int			 alg;
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	struct ssh_digest_ctx	*ictx;
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	struct ssh_digest_ctx	*octx;
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	struct ssh_digest_ctx	*digest;
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	u_char			*buf;
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	size_t			 buf_len;
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};
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size_t
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ssh_hmac_bytes(int alg)
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{
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	return ssh_digest_bytes(alg);
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}
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struct ssh_hmac_ctx *
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ssh_hmac_start(int alg)
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{
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	struct ssh_hmac_ctx	*ret;
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	if ((ret = calloc(1, sizeof(*ret))) == NULL)
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		return NULL;
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	ret->alg = alg;
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	if ((ret->ictx = ssh_digest_start(alg)) == NULL ||
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	    (ret->octx = ssh_digest_start(alg)) == NULL ||
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	    (ret->digest = ssh_digest_start(alg)) == NULL)
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		goto fail;
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	ret->buf_len = ssh_digest_blocksize(ret->ictx);
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	if ((ret->buf = calloc(1, ret->buf_len)) == NULL)
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		goto fail;
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	return ret;
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fail:
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	ssh_hmac_free(ret);
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	return NULL;
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}
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int
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ssh_hmac_init(struct ssh_hmac_ctx *ctx, const void *key, size_t klen)
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{
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	size_t i;
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	/* reset ictx and octx if no is key given */
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	if (key != NULL) {
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		/* truncate long keys */
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		if (klen <= ctx->buf_len)
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			memcpy(ctx->buf, key, klen);
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		else if (ssh_digest_memory(ctx->alg, key, klen, ctx->buf,
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		    ctx->buf_len) < 0)
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			return -1;
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		for (i = 0; i < ctx->buf_len; i++)
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			ctx->buf[i] ^= 0x36;
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		if (ssh_digest_update(ctx->ictx, ctx->buf, ctx->buf_len) < 0)
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			return -1;
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		for (i = 0; i < ctx->buf_len; i++)
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			ctx->buf[i] ^= 0x36 ^ 0x5c;
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		if (ssh_digest_update(ctx->octx, ctx->buf, ctx->buf_len) < 0)
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			return -1;
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		explicit_bzero(ctx->buf, ctx->buf_len);
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	}
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	/* start with ictx */
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	if (ssh_digest_copy_state(ctx->ictx, ctx->digest) < 0)
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		return -1;
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	return 0;
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}
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int
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ssh_hmac_update(struct ssh_hmac_ctx *ctx, const void *m, size_t mlen)
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{
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	return ssh_digest_update(ctx->digest, m, mlen);
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}
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int
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ssh_hmac_update_buffer(struct ssh_hmac_ctx *ctx, const struct sshbuf *b)
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{
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	return ssh_digest_update_buffer(ctx->digest, b);
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}
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int
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ssh_hmac_final(struct ssh_hmac_ctx *ctx, u_char *d, size_t dlen)
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{
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	size_t len;
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	len = ssh_digest_bytes(ctx->alg);
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	if (dlen < len ||
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	    ssh_digest_final(ctx->digest, ctx->buf, len))
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		return -1;
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	/* switch to octx */
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	if (ssh_digest_copy_state(ctx->octx, ctx->digest) < 0 ||
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	    ssh_digest_update(ctx->digest, ctx->buf, len) < 0 ||
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	    ssh_digest_final(ctx->digest, d, dlen) < 0)
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		return -1;
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	return 0;
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}
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void
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ssh_hmac_free(struct ssh_hmac_ctx *ctx)
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{
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	if (ctx != NULL) {
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		ssh_digest_free(ctx->ictx);
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		ssh_digest_free(ctx->octx);
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		ssh_digest_free(ctx->digest);
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		if (ctx->buf) {
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			explicit_bzero(ctx->buf, ctx->buf_len);
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			free(ctx->buf);
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		}
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		explicit_bzero(ctx, sizeof(*ctx));
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		free(ctx);
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	}
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}
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#ifdef TEST
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/* cc -DTEST hmac.c digest.c buffer.c cleanup.c fatal.c log.c xmalloc.c -lcrypto */
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static void
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hmac_test(void *key, size_t klen, void *m, size_t mlen, u_char *e, size_t elen)
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{
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	struct ssh_hmac_ctx	*ctx;
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	size_t			 i;
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	u_char			 digest[16];
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	if ((ctx = ssh_hmac_start(SSH_DIGEST_MD5)) == NULL)
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		printf("ssh_hmac_start failed");
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	if (ssh_hmac_init(ctx, key, klen) < 0 ||
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	    ssh_hmac_update(ctx, m, mlen) < 0 ||
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	    ssh_hmac_final(ctx, digest, sizeof(digest)) < 0)
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		printf("ssh_hmac_xxx failed");
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	ssh_hmac_free(ctx);
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	if (memcmp(e, digest, elen)) {
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		for (i = 0; i < elen; i++)
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			printf("[%zu] %2.2x %2.2x\n", i, e[i], digest[i]);
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		printf("mismatch\n");
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	} else
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		printf("ok\n");
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}
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int
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main(int argc, char **argv)
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{
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	/* try test vectors from RFC 2104 */
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	u_char key1[16] = {
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	    0xb, 0xb, 0xb, 0xb, 0xb, 0xb, 0xb, 0xb,
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	    0xb, 0xb, 0xb, 0xb, 0xb, 0xb, 0xb, 0xb };
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	u_char *data1 = "Hi There";
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	u_char dig1[16] = {
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	    0x92, 0x94, 0x72, 0x7a, 0x36, 0x38, 0xbb, 0x1c,
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	    0x13, 0xf4, 0x8e, 0xf8, 0x15, 0x8b, 0xfc, 0x9d };
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	u_char *key2 = "Jefe";
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	u_char *data2 = "what do ya want for nothing?";
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	u_char dig2[16] = {
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	    0x75, 0x0c, 0x78, 0x3e, 0x6a, 0xb0, 0xb5, 0x03,
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	    0xea, 0xa8, 0x6e, 0x31, 0x0a, 0x5d, 0xb7, 0x38 };
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	u_char key3[16];
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	u_char data3[50];
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	u_char dig3[16] = {
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	    0x56, 0xbe, 0x34, 0x52, 0x1d, 0x14, 0x4c, 0x88,
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	    0xdb, 0xb8, 0xc7, 0x33, 0xf0, 0xe8, 0xb3, 0xf6 };
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	memset(key3, 0xaa, sizeof(key3));
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	memset(data3, 0xdd, sizeof(data3));
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	hmac_test(key1, sizeof(key1), data1, strlen(data1), dig1, sizeof(dig1));
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	hmac_test(key2, strlen(key2), data2, strlen(data2), dig2, sizeof(dig2));
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	hmac_test(key3, sizeof(key3), data3, sizeof(data3), dig3, sizeof(dig3));
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	return 0;
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}
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#endif