- OpenBSD CVS Sync

   - djm@cvs.openbsd.org 2010/03/03 01:44:36
     [auth-options.c key.c]
     reject strings with embedded ASCII nul chars in certificate key IDs,
     principal names and constraints

1 files changed, 23 insertions, 13 deletions

diff --git a/key.c b/key.c
index 387190b53..e6266fa58 100644
--- a/key.c
+++ b/key.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: key.c,v 1.83 2010/02/26 20:29:54 djm Exp $ */
+/* $OpenBSD: key.c,v 1.84 2010/03/03 01:44:36 djm Exp $ */
 /*
  * read_bignum():
  * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
@@ -1000,7 +1000,7 @@ static int
 cert_parse(Buffer *b, Key *key, const u_char *blob, u_int blen)
 {
         u_char *principals, *constraints, *sig_key, *sig;
-        u_int signed_len, plen, clen, sklen, slen;
+        u_int signed_len, plen, clen, sklen, slen, kidlen;
         Buffer tmp;
         char *principal;
         int ret = -1;
@@ -1012,7 +1012,7 @@ cert_parse(Buffer *b, Key *key, const u_char *blob, u_int blen)
 
         principals = constraints = sig_key = sig = NULL;
         if (buffer_get_int_ret(&key->cert->type, b) != 0 ||
-            (key->cert->key_id = buffer_get_string_ret(b, NULL)) == NULL ||
+            (key->cert->key_id = buffer_get_string_ret(b, &kidlen)) == NULL ||
             (principals = buffer_get_string_ret(b, &plen)) == NULL ||
             buffer_get_int64_ret(&key->cert->valid_after, b) != 0 ||
             buffer_get_int64_ret(&key->cert->valid_before, b) != 0 ||
@@ -1024,6 +1024,11 @@ cert_parse(Buffer *b, Key *key, const u_char *blob, u_int blen)
                 goto out;
         }
 
+        if (kidlen != strlen(key->cert->key_id)) {
+                error("%s: key ID contains \\0 character", __func__);
+                goto out;
+        }
+
         /* Signature is left in the buffer so we can calculate this length */
         signed_len = buffer_len(&key->cert->certblob) - buffer_len(b);
 
@@ -1041,11 +1046,16 @@ cert_parse(Buffer *b, Key *key, const u_char *blob, u_int blen)
         buffer_append(&tmp, principals, plen);
         while (buffer_len(&tmp) > 0) {
                 if (key->cert->nprincipals >= CERT_MAX_PRINCIPALS) {
-                        error("Too many principals");
+                        error("%s: Too many principals", __func__);
                         goto out;
                 }
-                if ((principal = buffer_get_string_ret(&tmp, NULL)) == NULL) {
-                        error("Principals data invalid");
+                if ((principal = buffer_get_string_ret(&tmp, &plen)) == NULL) {
+                        error("%s: Principals data invalid", __func__);
+                        goto out;
+                }
+                if (strlen(principal) != plen) {
+                        error("%s: Principal contains \\0 character",
+                            __func__);
                         goto out;
                 }
                 key->cert->principals = xrealloc(key->cert->principals,
@@ -1061,7 +1071,7 @@ cert_parse(Buffer *b, Key *key, const u_char *blob, u_int blen)
         while (buffer_len(&tmp) != 0) {
                 if (buffer_get_string_ptr(&tmp, NULL) == NULL ||
                     buffer_get_string_ptr(&tmp, NULL) == NULL) {
-                        error("Constraints data invalid");
+                        error("%s: Constraints data invalid", __func__);
                         goto out;
                 }
         }
@@ -1069,12 +1079,12 @@ cert_parse(Buffer *b, Key *key, const u_char *blob, u_int blen)
 
         if ((key->cert->signature_key = key_from_blob(sig_key,
             sklen)) == NULL) {
-                error("Signature key invalid");
+                error("%s: Signature key invalid", __func__);
                 goto out;
         }
         if (key->cert->signature_key->type != KEY_RSA &&
             key->cert->signature_key->type != KEY_DSA) {
-                error("Invalid signature key type %s (%d)",
+                error("%s: Invalid signature key type %s (%d)", __func__,
                     key_type(key->cert->signature_key),
                     key->cert->signature_key->type);
                 goto out;
@@ -1083,17 +1093,17 @@ cert_parse(Buffer *b, Key *key, const u_char *blob, u_int blen)
         switch (key_verify(key->cert->signature_key, sig, slen, 
             buffer_ptr(&key->cert->certblob), signed_len)) {
         case 1:
+                ret = 0;
                 break; /* Good signature */
         case 0:
-                error("Invalid signature on certificate");
+                error("%s: Invalid signature on certificate", __func__);
                 goto out;
         case -1:
-                error("Certificate signature verification failed");
+                error("%s: Certificate signature verification failed",
+                    __func__);
                 goto out;
         }
 
-        ret = 0;
-
  out:
         buffer_free(&tmp);
         if (principals != NULL)