upstream commit

improve sshkey_read() semantics; only update *cpp when a
 key is successfully read; ok markus@

Upstream-ID: f371e78e8f4fab366cf69a42bdecedaed5d1b089

1 files changed, 15 insertions, 13 deletions

diff --git a/sshkey.c b/sshkey.c
index 7ceb915f8..c5185128a 100644
--- a/sshkey.c
+++ b/sshkey.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: sshkey.c,v 1.24 2015/10/15 23:08:23 djm Exp $ */
+/* $OpenBSD: sshkey.c,v 1.25 2015/11/16 22:50:01 djm Exp $ */
 /*
  * Copyright (c) 2000, 2001 Markus Friedl.  All rights reserved.
  * Copyright (c) 2008 Alexander von Gernler.  All rights reserved.
@@ -1232,11 +1232,10 @@ sshkey_read(struct sshkey *ret, char **cpp)
 {
         struct sshkey *k;
         int retval = SSH_ERR_INVALID_FORMAT;
-        char *cp, *space;
+        char *ep, *cp, *space;
         int r, type, curve_nid = -1;
         struct sshbuf *blob;
 #ifdef WITH_SSH1
-        char *ep;
         u_long bits;
 #endif /* WITH_SSH1 */
 
@@ -1255,10 +1254,10 @@ sshkey_read(struct sshkey *ret, char **cpp)
                         return r;
                 if ((r = read_decimal_bignum(&ep, ret->rsa->n)) < 0)
                         return r;
-                *cpp = ep;
                 /* validate the claimed number of bits */
                 if (BN_num_bits(ret->rsa->n) != (int)bits)
                         return SSH_ERR_KEY_BITS_MISMATCH;
+                *cpp = ep;
                 retval = 0;
 #endif /* WITH_SSH1 */
                 break;
@@ -1296,9 +1295,9 @@ sshkey_read(struct sshkey *ret, char **cpp)
                         *space++ = '\0';
                         while (*space == ' ' || *space == '\t')
                                 space++;
-                        *cpp = space;
+                        ep = space;
                 } else
-                        *cpp = cp + strlen(cp);
+                        ep = cp + strlen(cp);
                 if ((r = sshbuf_b64tod(blob, cp)) != 0) {
                         sshbuf_free(blob);
                         return r;
@@ -1329,8 +1328,9 @@ sshkey_read(struct sshkey *ret, char **cpp)
                         ret->cert = k->cert;
                         k->cert = NULL;
                 }
+                switch (sshkey_type_plain(ret->type)) {
 #ifdef WITH_OPENSSL
-                if (sshkey_type_plain(ret->type) == KEY_RSA) {
+                case KEY_RSA:
                         if (ret->rsa != NULL)
                                 RSA_free(ret->rsa);
                         ret->rsa = k->rsa;
@@ -1338,8 +1338,8 @@ sshkey_read(struct sshkey *ret, char **cpp)
 #ifdef DEBUG_PK
                         RSA_print_fp(stderr, ret->rsa, 8);
 #endif
-                }
-                if (sshkey_type_plain(ret->type) == KEY_DSA) {
+                        break;
+                case KEY_DSA:
                         if (ret->dsa != NULL)
                                 DSA_free(ret->dsa);
                         ret->dsa = k->dsa;
@@ -1347,9 +1347,9 @@ sshkey_read(struct sshkey *ret, char **cpp)
 #ifdef DEBUG_PK
                         DSA_print_fp(stderr, ret->dsa, 8);
 #endif
-                }
+                        break;
 # ifdef OPENSSL_HAS_ECC
-                if (sshkey_type_plain(ret->type) == KEY_ECDSA) {
+                case KEY_ECDSA:
                         if (ret->ecdsa != NULL)
                                 EC_KEY_free(ret->ecdsa);
                         ret->ecdsa = k->ecdsa;
@@ -1359,17 +1359,19 @@ sshkey_read(struct sshkey *ret, char **cpp)
 #ifdef DEBUG_PK
                         sshkey_dump_ec_key(ret->ecdsa);
 #endif
-                }
+                        break;
 # endif /* OPENSSL_HAS_ECC */
 #endif /* WITH_OPENSSL */
-                if (sshkey_type_plain(ret->type) == KEY_ED25519) {
+                case KEY_ED25519:
                         free(ret->ed25519_pk);
                         ret->ed25519_pk = k->ed25519_pk;
                         k->ed25519_pk = NULL;
 #ifdef DEBUG_PK
                         /* XXX */
 #endif
+                        break;
                 }
+                *cpp = ep;
                 retval = 0;
 /*XXXX*/
                 sshkey_free(k);