- djm@cvs.openbsd.org 2014/06/24 01:13:21

     [Makefile.in auth-bsdauth.c auth-chall.c auth-options.c auth-rsa.c
     [auth2-none.c auth2-pubkey.c authfile.c authfile.h cipher-3des1.c
     [cipher-chachapoly.c cipher-chachapoly.h cipher.c cipher.h
     [digest-libc.c digest-openssl.c digest.h dns.c entropy.c hmac.h
     [hostfile.c key.c key.h krl.c monitor.c packet.c rsa.c rsa.h
     [ssh-add.c ssh-agent.c ssh-dss.c ssh-ecdsa.c ssh-ed25519.c
     [ssh-keygen.c ssh-pkcs11-client.c ssh-pkcs11-helper.c ssh-pkcs11.c
     [ssh-rsa.c sshbuf-misc.c sshbuf.h sshconnect.c sshconnect1.c
     [sshconnect2.c sshd.c sshkey.c sshkey.h
     [openbsd-compat/openssl-compat.c openbsd-compat/openssl-compat.h]
     New key API: refactor key-related functions to be more library-like,
     existing API is offered as a set of wrappers.

     with and ok markus@

     Thanks also to Ben Hawkes, David Tomaschik, Ivan Fratric, Matthew
     Dempsky and Ron Bowes for a detailed review a few months ago.

     NB. This commit also removes portable OpenSSH support for OpenSSL
     <0.9.8e.

1 files changed, 123 insertions, 109 deletions

diff --git a/ssh-ecdsa.c b/ssh-ecdsa.c
index 551c9c460..1119db045 100644
--- a/ssh-ecdsa.c
+++ b/ssh-ecdsa.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: ssh-ecdsa.c,v 1.10 2014/02/03 23:28:00 djm Exp $ */
+/* $OpenBSD: ssh-ecdsa.c,v 1.11 2014/06/24 01:13:21 djm Exp $ */
 /*
  * Copyright (c) 2000 Markus Friedl.  All rights reserved.
  * Copyright (c) 2010 Damien Miller.  All rights reserved.
@@ -37,141 +37,155 @@
 
 #include <string.h>
 
-#include "xmalloc.h"
-#include "buffer.h"
-#include "compat.h"
-#include "log.h"
-#include "key.h"
+#include "sshbuf.h"
+#include "ssherr.h"
 #include "digest.h"
+#define SSHKEY_INTERNAL
+#include "sshkey.h"
 
+/* ARGSUSED */
 int
-ssh_ecdsa_sign(const Key *key, u_char **sigp, u_int *lenp,
-    const u_char *data, u_int datalen)
+ssh_ecdsa_sign(const struct sshkey *key, u_char **sigp, size_t *lenp,
+    const u_char *data, size_t datalen, u_int compat)
 {
-	ECDSA_SIG *sig;
+	ECDSA_SIG *sig = NULL;
 	int hash_alg;
 	u_char digest[SSH_DIGEST_MAX_LENGTH];
-	u_int len, dlen;
-	Buffer b, bb;
+	size_t len, dlen;
+	struct sshbuf *b = NULL, *bb = NULL;
+	int ret = SSH_ERR_INTERNAL_ERROR;
 
-	if (key == NULL || key_type_plain(key->type) != KEY_ECDSA ||
-	    key->ecdsa == NULL) {
-		error("%s: no ECDSA key", __func__);
-		return -1;
+	if (lenp != NULL)
+		*lenp = 0;
+	if (sigp != NULL)
+		*sigp = NULL;
+
+	if (key == NULL || key->ecdsa == NULL ||
+	    sshkey_type_plain(key->type) != KEY_ECDSA)
+		return SSH_ERR_INVALID_ARGUMENT;
+
+	if ((hash_alg = sshkey_ec_nid_to_hash_alg(key->ecdsa_nid)) == -1 ||
+	    (dlen = ssh_digest_bytes(hash_alg)) == 0)
+		return SSH_ERR_INTERNAL_ERROR;
+	if ((ret = ssh_digest_memory(hash_alg, data, datalen,
+	    digest, sizeof(digest))) != 0)
+		goto out;
+
+	if ((sig = ECDSA_do_sign(digest, dlen, key->ecdsa)) == NULL) {
+		ret = SSH_ERR_LIBCRYPTO_ERROR;
+		goto out;
 	}
 
-	hash_alg = key_ec_nid_to_hash_alg(key->ecdsa_nid);
-	if ((dlen = ssh_digest_bytes(hash_alg)) == 0) {
-		error("%s: bad hash algorithm %d", __func__, hash_alg);
-		return -1;
-	}
-	if (ssh_digest_memory(hash_alg, data, datalen,
-	    digest, sizeof(digest)) != 0) {
-		error("%s: digest_memory failed", __func__);
-		return -1;
+	if ((bb = sshbuf_new()) == NULL || (b = sshbuf_new()) == NULL) {
+		ret = SSH_ERR_ALLOC_FAIL;
+		goto out;
 	}
-
-	sig = ECDSA_do_sign(digest, dlen, key->ecdsa);
-	explicit_bzero(digest, sizeof(digest));
-
-	if (sig == NULL) {
-		error("%s: sign failed", __func__);
-		return -1;
+	if ((ret = sshbuf_put_bignum2(bb, sig->r)) != 0 ||
+	    (ret = sshbuf_put_bignum2(bb, sig->s)) != 0)
+		goto out;
+	if ((ret = sshbuf_put_cstring(b, sshkey_ssh_name_plain(key))) != 0 ||
+	    (ret = sshbuf_put_stringb(b, bb)) != 0)
+		goto out;
+	len = sshbuf_len(b);
+	if (sigp != NULL) {
+		if ((*sigp = malloc(len)) == NULL) {
+			ret = SSH_ERR_ALLOC_FAIL;
+			goto out;
+		}
+		memcpy(*sigp, sshbuf_ptr(b), len);
 	}
-
-	buffer_init(&bb);
-	buffer_put_bignum2(&bb, sig->r);
-	buffer_put_bignum2(&bb, sig->s);
-	ECDSA_SIG_free(sig);
-
-	buffer_init(&b);
-	buffer_put_cstring(&b, key_ssh_name_plain(key));
-	buffer_put_string(&b, buffer_ptr(&bb), buffer_len(&bb));
-	buffer_free(&bb);
-	len = buffer_len(&b);
 	if (lenp != NULL)
 		*lenp = len;
-	if (sigp != NULL) {
-		*sigp = xmalloc(len);
-		memcpy(*sigp, buffer_ptr(&b), len);
-	}
-	buffer_free(&b);
-
-	return 0;
+	ret = 0;
+ out:
+	explicit_bzero(digest, sizeof(digest));
+	if (b != NULL)
+		sshbuf_free(b);
+	if (bb != NULL)
+		sshbuf_free(bb);
+	if (sig != NULL)
+		ECDSA_SIG_free(sig);
+	return ret;
 }
+
+/* ARGSUSED */
 int
-ssh_ecdsa_verify(const Key *key, const u_char *signature, u_int signaturelen,
-    const u_char *data, u_int datalen)
+ssh_ecdsa_verify(const struct sshkey *key,
+    const u_char *signature, size_t signaturelen,
+    const u_char *data, size_t datalen, u_int compat)
 {
-	ECDSA_SIG *sig;
+	ECDSA_SIG *sig = NULL;
 	int hash_alg;
-	u_char digest[SSH_DIGEST_MAX_LENGTH], *sigblob;
-	u_int len, dlen;
-	int rlen, ret;
-	Buffer b, bb;
-	char *ktype;
-
-	if (key == NULL || key_type_plain(key->type) != KEY_ECDSA ||
-	    key->ecdsa == NULL) {
-		error("%s: no ECDSA key", __func__);
-		return -1;
-	}
+	u_char digest[SSH_DIGEST_MAX_LENGTH];
+	size_t dlen;
+	int ret = SSH_ERR_INTERNAL_ERROR;
+	struct sshbuf *b = NULL, *sigbuf = NULL;
+	char *ktype = NULL;
+
+	if (key == NULL || key->ecdsa == NULL ||
+	    sshkey_type_plain(key->type) != KEY_ECDSA)
+		return SSH_ERR_INVALID_ARGUMENT;
+
+	if ((hash_alg = sshkey_ec_nid_to_hash_alg(key->ecdsa_nid)) == -1 ||
+	    (dlen = ssh_digest_bytes(hash_alg)) == 0)
+		return SSH_ERR_INTERNAL_ERROR;
 
 	/* fetch signature */
-	buffer_init(&b);
-	buffer_append(&b, signature, signaturelen);
-	ktype = buffer_get_string(&b, NULL);
-	if (strcmp(key_ssh_name_plain(key), ktype) != 0) {
-		error("%s: cannot handle type %s", __func__, ktype);
-		buffer_free(&b);
-		free(ktype);
-		return -1;
+	if ((b = sshbuf_from(signature, signaturelen)) == NULL)
+		return SSH_ERR_ALLOC_FAIL;
+	if (sshbuf_get_cstring(b, &ktype, NULL) != 0 ||
+	    sshbuf_froms(b, &sigbuf) != 0) {
+		ret = SSH_ERR_INVALID_FORMAT;
+		goto out;
 	}
-	free(ktype);
-	sigblob = buffer_get_string(&b, &len);
-	rlen = buffer_len(&b);
-	buffer_free(&b);
-	if (rlen != 0) {
-		error("%s: remaining bytes in signature %d", __func__, rlen);
-		free(sigblob);
-		return -1;
+	if (strcmp(sshkey_ssh_name_plain(key), ktype) != 0) {
+		ret = SSH_ERR_KEY_TYPE_MISMATCH;
+		goto out;
+	}
+	if (sshbuf_len(b) != 0) {
+		ret = SSH_ERR_UNEXPECTED_TRAILING_DATA;
+		goto out;
 	}
 
 	/* parse signature */
-	if ((sig = ECDSA_SIG_new()) == NULL)
-		fatal("%s: ECDSA_SIG_new failed", __func__);
-
-	buffer_init(&bb);
-	buffer_append(&bb, sigblob, len);
-	buffer_get_bignum2(&bb, sig->r);
-	buffer_get_bignum2(&bb, sig->s);
-	if (buffer_len(&bb) != 0)
-		fatal("%s: remaining bytes in inner sigblob", __func__);
-	buffer_free(&bb);
-
-	/* clean up */
-	explicit_bzero(sigblob, len);
-	free(sigblob);
-
-	/* hash the data */
-	hash_alg = key_ec_nid_to_hash_alg(key->ecdsa_nid);
-	if ((dlen = ssh_digest_bytes(hash_alg)) == 0) {
-		error("%s: bad hash algorithm %d", __func__, hash_alg);
-		return -1;
+	if ((sig = ECDSA_SIG_new()) == NULL) {
+		ret = SSH_ERR_ALLOC_FAIL;
+		goto out;
+	}
+	if (sshbuf_get_bignum2(sigbuf, sig->r) != 0 ||
+	    sshbuf_get_bignum2(sigbuf, sig->s) != 0) {
+		ret = SSH_ERR_INVALID_FORMAT;
+		goto out;
+	}
+	if (sshbuf_len(sigbuf) != 0) {
+		ret = SSH_ERR_UNEXPECTED_TRAILING_DATA;
+		goto out;
 	}
-	if (ssh_digest_memory(hash_alg, data, datalen,
-	    digest, sizeof(digest)) != 0) {
-		error("%s: digest_memory failed", __func__);
-		return -1;
+	if ((ret = ssh_digest_memory(hash_alg, data, datalen,
+	    digest, sizeof(digest))) != 0)
+		goto out;
+
+	switch (ECDSA_do_verify(digest, dlen, sig, key->ecdsa)) {
+	case 1:
+		ret = 0;
+		break;
+	case 0:
+		ret = SSH_ERR_SIGNATURE_INVALID;
+		goto out;
+	default:
+		ret = SSH_ERR_LIBCRYPTO_ERROR;
+		goto out;
 	}
 
-	ret = ECDSA_do_verify(digest, dlen, sig, key->ecdsa);
+ out:
 	explicit_bzero(digest, sizeof(digest));
-
-	ECDSA_SIG_free(sig);
-
-	debug("%s: signature %s", __func__,
-	    ret == 1 ? "correct" : ret == 0 ? "incorrect" : "error");
+	if (sigbuf != NULL)
+		sshbuf_free(sigbuf);
+	if (b != NULL)
+		sshbuf_free(b);
+	if (sig != NULL)
+		ECDSA_SIG_free(sig);
+	free(ktype);
 	return ret;
 }