- markus@cvs.openbsd.org 2014/01/27 18:58:14

     [Makefile.in digest.c digest.h hostfile.c kex.h mac.c hmac.c hmac.h]
     replace openssl HMAC with an implementation based on our ssh_digest_*
     ok and feedback djm@

1 files changed, 41 insertions, 44 deletions

diff --git a/mac.c b/mac.c
index d3a0b935..4c4a6bf5 100644
--- a/mac.c
+++ b/mac.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: mac.c,v 1.26 2014/01/04 17:50:55 tedu Exp $ */
+/* $OpenBSD: mac.c,v 1.27 2014/01/27 18:58:14 markus Exp $ */
 /*
  * Copyright (c) 2001 Markus Friedl.  All rights reserved.
  *
@@ -27,8 +27,6 @@
 
 #include <sys/types.h>
 
-#include <openssl/hmac.h>
-
 #include <stdarg.h>
 #include <string.h>
 #include <signal.h>
@@ -42,18 +40,20 @@
 #include "mac.h"
 #include "misc.h"
 
+#include "digest.h"
+#include "hmac.h"
 #include "umac.h"
 
 #include "openbsd-compat/openssl-compat.h"
 
-#define SSH_EVP		1	/* OpenSSL EVP-based MAC */
+#define SSH_DIGEST	1	/* SSH_DIGEST_XXX */
 #define SSH_UMAC	2	/* UMAC (not integrated with OpenSSL) */
 #define SSH_UMAC128	3
 
 struct macalg {
 	char		*name;
 	int		type;
-	const EVP_MD *	(*mdfunc)(void);
+	int		alg;
 	int		truncatebits;	/* truncate digest if != 0 */
 	int		key_len;	/* just for UMAC */
 	int		len;		/* just for UMAC */
@@ -62,33 +62,33 @@ struct macalg {
 
 static const struct macalg macs[] = {
 	/* Encrypt-and-MAC (encrypt-and-authenticate) variants */
-	{ "hmac-sha1",				SSH_EVP, EVP_sha1, 0, 0, 0, 0 },
-	{ "hmac-sha1-96",			SSH_EVP, EVP_sha1, 96, 0, 0, 0 },
+	{ "hmac-sha1",				SSH_DIGEST, SSH_DIGEST_SHA1, 0, 0, 0, 0 },
+	{ "hmac-sha1-96",			SSH_DIGEST, SSH_DIGEST_SHA1, 96, 0, 0, 0 },
 #ifdef HAVE_EVP_SHA256
-	{ "hmac-sha2-256",			SSH_EVP, EVP_sha256, 0, 0, 0, 0 },
-	{ "hmac-sha2-512",			SSH_EVP, EVP_sha512, 0, 0, 0, 0 },
+	{ "hmac-sha2-256",			SSH_DIGEST, SSH_DIGEST_SHA256, 0, 0, 0, 0 },
+	{ "hmac-sha2-512",			SSH_DIGEST, SSH_DIGEST_SHA512, 0, 0, 0, 0 },
 #endif
-	{ "hmac-md5",				SSH_EVP, EVP_md5, 0, 0, 0, 0 },
-	{ "hmac-md5-96",			SSH_EVP, EVP_md5, 96, 0, 0, 0 },
-	{ "hmac-ripemd160",			SSH_EVP, EVP_ripemd160, 0, 0, 0, 0 },
-	{ "hmac-ripemd160@openssh.com",		SSH_EVP, EVP_ripemd160, 0, 0, 0, 0 },
-	{ "umac-64@openssh.com",		SSH_UMAC, NULL, 0, 128, 64, 0 },
-	{ "umac-128@openssh.com",		SSH_UMAC128, NULL, 0, 128, 128, 0 },
+	{ "hmac-md5",				SSH_DIGEST, SSH_DIGEST_MD5, 0, 0, 0, 0 },
+	{ "hmac-md5-96",			SSH_DIGEST, SSH_DIGEST_MD5, 96, 0, 0, 0 },
+	{ "hmac-ripemd160",			SSH_DIGEST, SSH_DIGEST_RIPEMD160, 0, 0, 0, 0 },
+	{ "hmac-ripemd160@openssh.com",		SSH_DIGEST, SSH_DIGEST_RIPEMD160, 0, 0, 0, 0 },
+	{ "umac-64@openssh.com",		SSH_UMAC, 0, 0, 128, 64, 0 },
+	{ "umac-128@openssh.com",		SSH_UMAC128, 0, 0, 128, 128, 0 },
 
 	/* Encrypt-then-MAC variants */
-	{ "hmac-sha1-etm@openssh.com",		SSH_EVP, EVP_sha1, 0, 0, 0, 1 },
-	{ "hmac-sha1-96-etm@openssh.com",	SSH_EVP, EVP_sha1, 96, 0, 0, 1 },
+	{ "hmac-sha1-etm@openssh.com",		SSH_DIGEST, SSH_DIGEST_SHA1, 0, 0, 0, 1 },
+	{ "hmac-sha1-96-etm@openssh.com",	SSH_DIGEST, SSH_DIGEST_SHA1, 96, 0, 0, 1 },
 #ifdef HAVE_EVP_SHA256
-	{ "hmac-sha2-256-etm@openssh.com",	SSH_EVP, EVP_sha256, 0, 0, 0, 1 },
-	{ "hmac-sha2-512-etm@openssh.com",	SSH_EVP, EVP_sha512, 0, 0, 0, 1 },
+	{ "hmac-sha2-256-etm@openssh.com",	SSH_DIGEST, SSH_DIGEST_SHA256, 0, 0, 0, 1 },
+	{ "hmac-sha2-512-etm@openssh.com",	SSH_DIGEST, SSH_DIGEST_SHA512, 0, 0, 0, 1 },
 #endif
-	{ "hmac-md5-etm@openssh.com",		SSH_EVP, EVP_md5, 0, 0, 0, 1 },
-	{ "hmac-md5-96-etm@openssh.com",	SSH_EVP, EVP_md5, 96, 0, 0, 1 },
-	{ "hmac-ripemd160-etm@openssh.com",	SSH_EVP, EVP_ripemd160, 0, 0, 0, 1 },
-	{ "umac-64-etm@openssh.com",		SSH_UMAC, NULL, 0, 128, 64, 1 },
-	{ "umac-128-etm@openssh.com",		SSH_UMAC128, NULL, 0, 128, 128, 1 },
+	{ "hmac-md5-etm@openssh.com",		SSH_DIGEST, SSH_DIGEST_MD5, 0, 0, 0, 1 },
+	{ "hmac-md5-96-etm@openssh.com",	SSH_DIGEST, SSH_DIGEST_MD5, 96, 0, 0, 1 },
+	{ "hmac-ripemd160-etm@openssh.com",	SSH_DIGEST, SSH_DIGEST_RIPEMD160, 0, 0, 0, 1 },
+	{ "umac-64-etm@openssh.com",		SSH_UMAC, 0, 0, 128, 64, 1 },
+	{ "umac-128-etm@openssh.com",		SSH_UMAC128, 0, 0, 128, 128, 1 },
 
-	{ NULL,					0, NULL, 0, 0, 0, 0 }
+	{ NULL,					0, 0, 0, 0, 0, 0 }
 };
 
 /* Returns a list of supported MACs separated by the specified char. */
@@ -113,14 +113,11 @@ mac_alg_list(char sep)
 static void
 mac_setup_by_alg(Mac *mac, const struct macalg *macalg)
 {
-	int evp_len;
-
 	mac->type = macalg->type;
-	if (mac->type == SSH_EVP) {
-		mac->evp_md = macalg->mdfunc();
-		if ((evp_len = EVP_MD_size(mac->evp_md)) <= 0)
-			fatal("mac %s len %d", mac->name, evp_len);
-		mac->key_len = mac->mac_len = (u_int)evp_len;
+	if (mac->type == SSH_DIGEST) {
+		if ((mac->hmac_ctx = ssh_hmac_start(macalg->alg)) == NULL)
+			fatal("ssh_hmac_start(alg=%d) failed", macalg->alg);
+		mac->key_len = mac->mac_len = ssh_hmac_bytes(macalg->alg);
 	} else {
 		mac->mac_len = macalg->len / 8;
 		mac->key_len = macalg->key_len / 8;
@@ -154,11 +151,10 @@ mac_init(Mac *mac)
 	if (mac->key == NULL)
 		fatal("mac_init: no key");
 	switch (mac->type) {
-	case SSH_EVP:
-		if (mac->evp_md == NULL)
+	case SSH_DIGEST:
+		if (mac->hmac_ctx == NULL ||
+		    ssh_hmac_init(mac->hmac_ctx, mac->key, mac->key_len) < 0)
 			return -1;
-		HMAC_CTX_init(&mac->evp_ctx);
-		HMAC_Init(&mac->evp_ctx, mac->key, mac->key_len, mac->evp_md);
 		return 0;
 	case SSH_UMAC:
 		mac->umac_ctx = umac_new(mac->key);
@@ -185,13 +181,14 @@ mac_compute(Mac *mac, u_int32_t seqno, u_char *data, int datalen)
 		    mac->mac_len, sizeof(u));
 
 	switch (mac->type) {
-	case SSH_EVP:
+	case SSH_DIGEST:
 		put_u32(b, seqno);
 		/* reset HMAC context */
-		HMAC_Init(&mac->evp_ctx, NULL, 0, NULL);
-		HMAC_Update(&mac->evp_ctx, b, sizeof(b));
-		HMAC_Update(&mac->evp_ctx, data, datalen);
-		HMAC_Final(&mac->evp_ctx, u.m, NULL);
+		if (ssh_hmac_init(mac->hmac_ctx, NULL, 0) < 0 ||
+		    ssh_hmac_update(mac->hmac_ctx, b, sizeof(b)) < 0 ||
+		    ssh_hmac_update(mac->hmac_ctx, data, datalen) < 0 ||
+		    ssh_hmac_final(mac->hmac_ctx, u.m, sizeof(u.m)) < 0)
+			fatal("ssh_hmac failed");
 		break;
 	case SSH_UMAC:
 		put_u64(nonce, seqno);
@@ -218,9 +215,9 @@ mac_clear(Mac *mac)
 	} else if (mac->type == SSH_UMAC128) {
 		if (mac->umac_ctx != NULL)
 			umac128_delete(mac->umac_ctx);
-	} else if (mac->evp_md != NULL)
-		HMAC_cleanup(&mac->evp_ctx);
-	mac->evp_md = NULL;
+	} else if (mac->hmac_ctx != NULL)
+		ssh_hmac_free(mac->hmac_ctx);
+	mac->hmac_ctx = NULL;
 	mac->umac_ctx = NULL;
 }