Merge 6.7p1.

  * New upstream release (http://www.openssh.com/txt/release-6.7):
    - sshd(8): The default set of ciphers and MACs has been altered to
      remove unsafe algorithms.  In particular, CBC ciphers and arcfour* are
      disabled by default.  The full set of algorithms remains available if
      configured explicitly via the Ciphers and MACs sshd_config options.
    - ssh(1), sshd(8): Add support for Unix domain socket forwarding.  A
      remote TCP port may be forwarded to a local Unix domain socket and
      vice versa or both ends may be a Unix domain socket (closes: #236718).
    - ssh(1), ssh-keygen(1): Add support for SSHFP DNS records for ED25519
      key types.
    - sftp(1): Allow resumption of interrupted uploads.
    - ssh(1): When rekeying, skip file/DNS lookups of the hostkey if it is
      the same as the one sent during initial key exchange.
    - sshd(8): Allow explicit ::1 and 127.0.0.1 forwarding bind addresses
      when GatewayPorts=no; allows client to choose address family.
    - sshd(8): Add a sshd_config PermitUserRC option to control whether
      ~/.ssh/rc is executed, mirroring the no-user-rc authorized_keys
      option.
    - ssh(1): Add a %C escape sequence for LocalCommand and ControlPath that
      expands to a unique identifer based on a hash of the tuple of (local
      host, remote user, hostname, port).  Helps avoid exceeding miserly
      pathname limits for Unix domain sockets in multiplexing control paths.
    - sshd(8): Make the "Too many authentication failures" message include
      the user, source address, port and protocol in a format similar to the
      authentication success / failure messages.
    - Use CLOCK_BOOTTIME in preference to CLOCK_MONOTONIC when it is
      available. It considers time spent suspended, thereby ensuring
      timeouts (e.g. for expiring agent keys) fire correctly (closes:
      #734553).
    - Use prctl() to prevent sftp-server from accessing
      /proc/self/{mem,maps}.
  * Restore TCP wrappers support, removed upstream in 6.7.  It is true that
    dropping this reduces preauth attack surface in sshd.  On the other
    hand, this support seems to be quite widely used, and abruptly dropping
    it (from the perspective of users who don't read openssh-unix-dev) could
    easily cause more serious problems in practice.  It's not entirely clear
    what the right long-term answer for Debian is, but it at least probably
    doesn't involve dropping this feature shortly before a freeze.
  * Replace patch to disable OpenSSL version check with an updated version
    of Kurt Roeckx's patch from #732940 to just avoid checking the status
    field.

1 files changed, 134 insertions, 104 deletions

diff --git a/ssh-dss.c b/ssh-dss.c
index 6b4abcb7d..9643d90d8 100644
--- a/ssh-dss.c
+++ b/ssh-dss.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: ssh-dss.c,v 1.31 2014/02/02 03:44:31 djm Exp $ */
+/* $OpenBSD: ssh-dss.c,v 1.32 2014/06/24 01:13:21 djm Exp $ */
 /*
  * Copyright (c) 2000 Markus Friedl.  All rights reserved.
  *
@@ -28,162 +28,192 @@
 #include <sys/types.h>
 
 #include <openssl/bn.h>
+#include <openssl/dsa.h>
 #include <openssl/evp.h>
 
 #include <stdarg.h>
 #include <string.h>
 
-#include "xmalloc.h"
-#include "buffer.h"
+#include "sshbuf.h"
 #include "compat.h"
-#include "log.h"
-#include "key.h"
+#include "ssherr.h"
 #include "digest.h"
+#define SSHKEY_INTERNAL
+#include "sshkey.h"
 
 #define INTBLOB_LEN     20
 #define SIGBLOB_LEN     (2*INTBLOB_LEN)
 
 int
-ssh_dss_sign(const Key *key, u_char **sigp, u_int *lenp,
-    const u_char *data, u_int datalen)
+ssh_dss_sign(const struct sshkey *key, u_char **sigp, size_t *lenp,
+    const u_char *data, size_t datalen, u_int compat)
 {
-        DSA_SIG *sig;
+        DSA_SIG *sig = NULL;
         u_char digest[SSH_DIGEST_MAX_LENGTH], sigblob[SIGBLOB_LEN];
-        u_int rlen, slen, len, dlen = ssh_digest_bytes(SSH_DIGEST_SHA1);
-        Buffer b;
-
-        if (key == NULL || key_type_plain(key->type) != KEY_DSA ||
-            key->dsa == NULL) {
-                error("%s: no DSA key", __func__);
-                return -1;
-        }
-
-        if (ssh_digest_memory(SSH_DIGEST_SHA1, data, datalen,
-            digest, sizeof(digest)) != 0) {
-                error("%s: ssh_digest_memory failed", __func__);
-                return -1;
-        }
-
-        sig = DSA_do_sign(digest, dlen, key->dsa);
-        explicit_bzero(digest, sizeof(digest));
-
-        if (sig == NULL) {
-                error("ssh_dss_sign: sign failed");
-                return -1;
+        size_t rlen, slen, len, dlen = ssh_digest_bytes(SSH_DIGEST_SHA1);
+        struct sshbuf *b = NULL;
+        int ret = SSH_ERR_INVALID_ARGUMENT;
+
+        if (lenp != NULL)
+                *lenp = 0;
+        if (sigp != NULL)
+                *sigp = NULL;
+
+        if (key == NULL || key->dsa == NULL ||
+            sshkey_type_plain(key->type) != KEY_DSA)
+                return SSH_ERR_INVALID_ARGUMENT;
+        if (dlen == 0)
+                return SSH_ERR_INTERNAL_ERROR;
+
+        if ((ret = ssh_digest_memory(SSH_DIGEST_SHA1, data, datalen,
+            digest, sizeof(digest))) != 0)
+                goto out;
+
+        if ((sig = DSA_do_sign(digest, dlen, key->dsa)) == NULL) {
+                ret = SSH_ERR_LIBCRYPTO_ERROR;
+                goto out;
         }
 
         rlen = BN_num_bytes(sig->r);
         slen = BN_num_bytes(sig->s);
         if (rlen > INTBLOB_LEN || slen > INTBLOB_LEN) {
-                error("bad sig size %u %u", rlen, slen);
-                DSA_SIG_free(sig);
-                return -1;
+                ret = SSH_ERR_INTERNAL_ERROR;
+                goto out;
         }
         explicit_bzero(sigblob, SIGBLOB_LEN);
-        BN_bn2bin(sig->r, sigblob+ SIGBLOB_LEN - INTBLOB_LEN - rlen);
-        BN_bn2bin(sig->s, sigblob+ SIGBLOB_LEN - slen);
-        DSA_SIG_free(sig);
+        BN_bn2bin(sig->r, sigblob + SIGBLOB_LEN - INTBLOB_LEN - rlen);
+        BN_bn2bin(sig->s, sigblob + SIGBLOB_LEN - slen);
 
-        if (datafellows & SSH_BUG_SIGBLOB) {
-                if (lenp != NULL)
-                        *lenp = SIGBLOB_LEN;
+        if (compat & SSH_BUG_SIGBLOB) {
                 if (sigp != NULL) {
-                        *sigp = xmalloc(SIGBLOB_LEN);
+                        if ((*sigp = malloc(SIGBLOB_LEN)) == NULL) {
+                                ret = SSH_ERR_ALLOC_FAIL;
+                                goto out;
+                        }
                         memcpy(*sigp, sigblob, SIGBLOB_LEN);
                 }
+                if (lenp != NULL)
+                        *lenp = SIGBLOB_LEN;
+                ret = 0;
         } else {
                 /* ietf-drafts */
-                buffer_init(&b);
-                buffer_put_cstring(&b, "ssh-dss");
-                buffer_put_string(&b, sigblob, SIGBLOB_LEN);
-                len = buffer_len(&b);
-                if (lenp != NULL)
-                        *lenp = len;
+                if ((b = sshbuf_new()) == NULL) {
+                        ret = SSH_ERR_ALLOC_FAIL;
+                        goto out;
+                }
+                if ((ret = sshbuf_put_cstring(b, "ssh-dss")) != 0 ||
+                    (ret = sshbuf_put_string(b, sigblob, SIGBLOB_LEN)) != 0)
+                        goto out;
+                len = sshbuf_len(b);
                 if (sigp != NULL) {
-                        *sigp = xmalloc(len);
-                        memcpy(*sigp, buffer_ptr(&b), len);
+                        if ((*sigp = malloc(len)) == NULL) {
+                                ret = SSH_ERR_ALLOC_FAIL;
+                                goto out;
+                        }
+                        memcpy(*sigp, sshbuf_ptr(b), len);
                 }
-                buffer_free(&b);
+                if (lenp != NULL)
+                        *lenp = len;
+                ret = 0;
         }
-        return 0;
+ out:
+        explicit_bzero(digest, sizeof(digest));
+        if (sig != NULL)
+                DSA_SIG_free(sig);
+        if (b != NULL)
+                sshbuf_free(b);
+        return ret;
 }
+
 int
-ssh_dss_verify(const Key *key, const u_char *signature, u_int signaturelen,
-    const u_char *data, u_int datalen)
+ssh_dss_verify(const struct sshkey *key,
+    const u_char *signature, size_t signaturelen,
+    const u_char *data, size_t datalen, u_int compat)
 {
-        DSA_SIG *sig;
-        u_char digest[SSH_DIGEST_MAX_LENGTH], *sigblob;
-        u_int len, dlen = ssh_digest_bytes(SSH_DIGEST_SHA1);
-        int rlen, ret;
-        Buffer b;
-
-        if (key == NULL || key_type_plain(key->type) != KEY_DSA ||
-            key->dsa == NULL) {
-                error("%s: no DSA key", __func__);
-                return -1;
-        }
+        DSA_SIG *sig = NULL;
+        u_char digest[SSH_DIGEST_MAX_LENGTH], *sigblob = NULL;
+        size_t len, dlen = ssh_digest_bytes(SSH_DIGEST_SHA1);
+        int ret = SSH_ERR_INTERNAL_ERROR;
+        struct sshbuf *b = NULL;
+        char *ktype = NULL;
+
+        if (key == NULL || key->dsa == NULL ||
+            sshkey_type_plain(key->type) != KEY_DSA)
+                return SSH_ERR_INVALID_ARGUMENT;
+        if (dlen == 0)
+                return SSH_ERR_INTERNAL_ERROR;
 
         /* fetch signature */
-        if (datafellows & SSH_BUG_SIGBLOB) {
-                sigblob = xmalloc(signaturelen);
+        if (compat & SSH_BUG_SIGBLOB) {
+                if ((sigblob = malloc(signaturelen)) == NULL)
+                        return SSH_ERR_ALLOC_FAIL;
                 memcpy(sigblob, signature, signaturelen);
                 len = signaturelen;
         } else {
                 /* ietf-drafts */
-                char *ktype;
-                buffer_init(&b);
-                buffer_append(&b, signature, signaturelen);
-                ktype = buffer_get_cstring(&b, NULL);
+                if ((b = sshbuf_from(signature, signaturelen)) == NULL)
+                        return SSH_ERR_ALLOC_FAIL;
+                if (sshbuf_get_cstring(b, &ktype, NULL) != 0 ||
+                    sshbuf_get_string(b, &sigblob, &len) != 0) {
+                        ret = SSH_ERR_INVALID_FORMAT;
+                        goto out;
+                }
                 if (strcmp("ssh-dss", ktype) != 0) {
-                        error("%s: cannot handle type %s", __func__, ktype);
-                        buffer_free(&b);
-                        free(ktype);
-                        return -1;
+                        ret = SSH_ERR_KEY_TYPE_MISMATCH;
+                        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 (sshbuf_len(b) != 0) {
+                        ret = SSH_ERR_UNEXPECTED_TRAILING_DATA;
+                        goto out;
                 }
         }
 
         if (len != SIGBLOB_LEN) {
-                fatal("bad sigbloblen %u != SIGBLOB_LEN", len);
+                ret = SSH_ERR_INVALID_FORMAT;
+                goto out;
         }
 
         /* parse signature */
-        if ((sig = DSA_SIG_new()) == NULL)
-                fatal("%s: DSA_SIG_new failed", __func__);
-        if ((sig->r = BN_new()) == NULL)
-                fatal("%s: BN_new failed", __func__);
-        if ((sig->s = BN_new()) == NULL)
-                fatal("ssh_dss_verify: BN_new failed");
+        if ((sig = DSA_SIG_new()) == NULL ||
+            (sig->r = BN_new()) == NULL ||
+            (sig->s = BN_new()) == NULL) {
+                ret = SSH_ERR_ALLOC_FAIL;
+                goto out;
+        }
         if ((BN_bin2bn(sigblob, INTBLOB_LEN, sig->r) == NULL) ||
-            (BN_bin2bn(sigblob+ INTBLOB_LEN, INTBLOB_LEN, sig->s) == NULL))
-                fatal("%s: BN_bin2bn failed", __func__);
-
-        /* clean up */
-        explicit_bzero(sigblob, len);
-        free(sigblob);
+            (BN_bin2bn(sigblob+ INTBLOB_LEN, INTBLOB_LEN, sig->s) == NULL)) {
+                ret = SSH_ERR_LIBCRYPTO_ERROR;
+                goto out;
+        }
 
         /* sha1 the data */
-        if (ssh_digest_memory(SSH_DIGEST_SHA1, data, datalen,
-            digest, sizeof(digest)) != 0) {
-                error("%s: digest_memory failed", __func__);
-                return -1;
+        if ((ret = ssh_digest_memory(SSH_DIGEST_SHA1, data, datalen,
+            digest, sizeof(digest))) != 0)
+                goto out;
+
+        switch (DSA_do_verify(digest, dlen, sig, key->dsa)) {
+        case 1:
+                ret = 0;
+                break;
+        case 0:
+                ret = SSH_ERR_SIGNATURE_INVALID;
+                goto out;
+        default:
+                ret = SSH_ERR_LIBCRYPTO_ERROR;
+                goto out;
         }
 
-        ret = DSA_do_verify(digest, dlen, sig, key->dsa);
+ out:
         explicit_bzero(digest, sizeof(digest));
-
-        DSA_SIG_free(sig);
-
-        debug("%s: signature %s", __func__,
-            ret == 1 ? "correct" : ret == 0 ? "incorrect" : "error");
+        if (sig != NULL)
+                DSA_SIG_free(sig);
+        if (b != NULL)
+                sshbuf_free(b);
+        if (ktype != NULL)
+                free(ktype);
+        if (sigblob != NULL) {
+                explicit_bzero(sigblob, len);
+                free(sigblob);
+        }
         return ret;
 }