- 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;
 }