- djm@cvs.openbsd.org 2010/10/28 11:22:09

     [authfile.c key.c key.h ssh-keygen.c]
     fix a possible NULL deref on loading a corrupt ECDH key

     store ECDH group information in private keys files as "named groups"
     rather than as a set of explicit group parameters (by setting
     the OPENSSL_EC_NAMED_CURVE flag). This makes for shorter key files and
     retrieves the group's OpenSSL NID that we need for various things.

1 files changed, 5 insertions, 9 deletions

diff --git a/authfile.c b/authfile.c
index b1e3eda5c..7f98ab547 100644
--- a/authfile.c
+++ b/authfile.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: authfile.c,v 1.84 2010/09/08 03:54:36 djm Exp $ */
+/* $OpenBSD: authfile.c,v 1.85 2010/10/28 11:22:09 djm Exp $ */
 /*
  * Author: Tatu Ylonen <ylo@cs.hut.fi>
  * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
@@ -523,13 +523,9 @@ key_load_private_pem(int fd, int type, const char *passphrase,
                 prv = key_new(KEY_UNSPEC);
                 prv->ecdsa = EVP_PKEY_get1_EC_KEY(pk);
                 prv->type = KEY_ECDSA;
-                prv->ecdsa_nid = key_ecdsa_group_to_nid(
-                    EC_KEY_get0_group(prv->ecdsa));
-                if (key_curve_nid_to_name(prv->ecdsa_nid) == NULL) {
-                        key_free(prv);
-                        prv = NULL;
-                }
-                if (key_ec_validate_public(EC_KEY_get0_group(prv->ecdsa),
+                if ((prv->ecdsa_nid = key_ecdsa_key_to_nid(prv->ecdsa)) == -1 ||
+                    key_curve_nid_to_name(prv->ecdsa_nid) == NULL ||
+                    key_ec_validate_public(EC_KEY_get0_group(prv->ecdsa),
                     EC_KEY_get0_public_key(prv->ecdsa)) != 0 ||
                     key_ec_validate_private(prv->ecdsa) != 0) {
                         error("%s: bad ECDSA key", __func__);
@@ -538,7 +534,7 @@ key_load_private_pem(int fd, int type, const char *passphrase,
                 }
                 name = "ecdsa w/o comment";
 #ifdef DEBUG_PK
-                if (prv->ecdsa != NULL)
+                if (prv != NULL && prv->ecdsa != NULL)
                         key_dump_ec_key(prv->ecdsa);
 #endif
 #endif /* OPENSSL_HAS_ECC */