merge key exchange patch without rekeying support

[openssh.git] / sshconnect2.c

diff --git a/sshconnect2.c b/sshconnect2.c
index 3cb9b10..aaf02ec 100644 (file)
--- a/sshconnect2.c
+++ b/sshconnect2.c
@@ -159,9 +159,34 @@ ssh_kex2(char *host, struct sockaddr *hostaddr, u_short port)
 {
        Kex *kex;
 
+#ifdef GSSAPI
+       char *orig = NULL, *gss = NULL;
+       char *gss_host = NULL;
+#endif
+
        xxx_host = host;
        xxx_hostaddr = hostaddr;
 
+#ifdef GSSAPI
+       if (options.gss_keyex) {
+               /* Add the GSSAPI mechanisms currently supported on this 
+                * client to the key exchange algorithm proposal */
+               orig = myproposal[PROPOSAL_KEX_ALGS];
+
+               if (options.gss_trust_dns)
+                       gss_host = (char *)get_canonical_hostname(1);
+               else
+                       gss_host = host;
+
+               gss = ssh_gssapi_client_mechanisms(gss_host, options.gss_client_identity);
+               if (gss) {
+                       debug("Offering GSSAPI proposal: %s", gss);
+                       xasprintf(&myproposal[PROPOSAL_KEX_ALGS],
+                           "%s,%s", gss, orig);
+               }
+       }
+#endif
+
        if (options.ciphers == (char *)-1) {
                logit("No valid ciphers for protocol version 2 given, using defaults.");
                options.ciphers = NULL;
@@ -196,6 +221,17 @@ ssh_kex2(char *host, struct sockaddr *hostaddr, u_short port)
        if (options.kex_algorithms != NULL)
                myproposal[PROPOSAL_KEX_ALGS] = options.kex_algorithms;
 
+#ifdef GSSAPI
+       /* If we've got GSSAPI algorithms, then we also support the
+        * 'null' hostkey, as a last resort */
+       if (options.gss_keyex && gss) {
+               orig = myproposal[PROPOSAL_SERVER_HOST_KEY_ALGS];
+               xasprintf(&myproposal[PROPOSAL_SERVER_HOST_KEY_ALGS], 
+                   "%s,null", orig);
+               xfree(gss);
+       }
+#endif
+
        if (options.rekey_limit)
                packet_set_rekey_limit((u_int32_t)options.rekey_limit);
 
@@ -206,10 +242,30 @@ ssh_kex2(char *host, struct sockaddr *hostaddr, u_short port)
        kex->kex[KEX_DH_GEX_SHA1] = kexgex_client;
        kex->kex[KEX_DH_GEX_SHA256] = kexgex_client;
        kex->kex[KEX_ECDH_SHA2] = kexecdh_client;
+#ifdef GSSAPI
+       if (options.gss_keyex) {
+               kex->kex[KEX_GSS_GRP1_SHA1] = kexgss_client;
+               kex->kex[KEX_GSS_GRP14_SHA1] = kexgss_client;
+               kex->kex[KEX_GSS_GEX_SHA1] = kexgss_client;
+       }
+#endif
        kex->client_version_string=client_version_string;
        kex->server_version_string=server_version_string;
        kex->verify_host_key=&verify_host_key_callback;
 
+#ifdef GSSAPI
+       if (options.gss_keyex) {
+               kex->gss_deleg_creds = options.gss_deleg_creds;
+               kex->gss_trust_dns = options.gss_trust_dns;
+               kex->gss_client = options.gss_client_identity;
+               if (options.gss_server_identity) {
+                       kex->gss_host = options.gss_server_identity;
+               } else {
+                       kex->gss_host = gss_host;
+        }
+       }
+#endif
+
        xxx_kex = kex;
 
        dispatch_run(DISPATCH_BLOCK, &kex->done, kex);
@@ -304,6 +360,7 @@ void        input_gssapi_token(int type, u_int32_t, void *);
 void   input_gssapi_hash(int type, u_int32_t, void *);
 void   input_gssapi_error(int, u_int32_t, void *);
 void   input_gssapi_errtok(int, u_int32_t, void *);
+int    userauth_gsskeyex(Authctxt *authctxt);
 #endif
 
 void   userauth(Authctxt *, char *);
@@ -319,6 +376,11 @@ static char *authmethods_get(void);
 
 Authmethod authmethods[] = {
 #ifdef GSSAPI
+       {"gssapi-keyex",
+               userauth_gsskeyex,
+               NULL,
+               &options.gss_authentication,
+               NULL},
        {"gssapi-with-mic",
                userauth_gssapi,
                NULL,
@@ -625,19 +687,31 @@ userauth_gssapi(Authctxt *authctxt)
        static u_int mech = 0;
        OM_uint32 min;
        int ok = 0;
+       const char *gss_host;
+
+       if (options.gss_server_identity)
+               gss_host = options.gss_server_identity;
+       else if (options.gss_trust_dns)
+               gss_host = get_canonical_hostname(1);
+       else
+               gss_host = authctxt->host;
 
        /* Try one GSSAPI method at a time, rather than sending them all at
         * once. */
 
        if (gss_supported == NULL)
-               gss_indicate_mechs(&min, &gss_supported);
+               if (GSS_ERROR(gss_indicate_mechs(&min, &gss_supported))) {
+                       gss_supported = NULL;
+                       return 0;
+               }
 
        /* Check to see if the mechanism is usable before we offer it */
        while (mech < gss_supported->count && !ok) {
                /* My DER encoding requires length<128 */
                if (gss_supported->elements[mech].length < 128 &&
                    ssh_gssapi_check_mechanism(&gssctxt, 
-                   &gss_supported->elements[mech], authctxt->host)) {
+                   &gss_supported->elements[mech], gss_host, 
+                    options.gss_client_identity)) {
                        ok = 1; /* Mechanism works */
                } else {
                        mech++;
@@ -734,8 +808,8 @@ input_gssapi_response(int type, u_int32_t plen, void *ctxt)
 {
        Authctxt *authctxt = ctxt;
        Gssctxt *gssctxt;
-       int oidlen;
-       char *oidv;
+       u_int oidlen;
+       u_char *oidv;
 
        if (authctxt == NULL)
                fatal("input_gssapi_response: no authentication context");
@@ -845,6 +919,48 @@ input_gssapi_error(int type, u_int32_t plen, void *ctxt)
        xfree(msg);
        xfree(lang);
 }
+
+int
+userauth_gsskeyex(Authctxt *authctxt)
+{
+       Buffer b;
+       gss_buffer_desc gssbuf;
+       gss_buffer_desc mic = GSS_C_EMPTY_BUFFER;
+       OM_uint32 ms;
+
+       static int attempt = 0;
+       if (attempt++ >= 1)
+               return (0);
+
+       if (gss_kex_context == NULL) {
+               debug("No valid Key exchange context"); 
+               return (0);
+       }
+
+       ssh_gssapi_buildmic(&b, authctxt->server_user, authctxt->service,
+           "gssapi-keyex");
+
+       gssbuf.value = buffer_ptr(&b);
+       gssbuf.length = buffer_len(&b);
+
+       if (GSS_ERROR(ssh_gssapi_sign(gss_kex_context, &gssbuf, &mic))) {
+               buffer_free(&b);
+               return (0);
+       }
+
+       packet_start(SSH2_MSG_USERAUTH_REQUEST);
+       packet_put_cstring(authctxt->server_user);
+       packet_put_cstring(authctxt->service);
+       packet_put_cstring(authctxt->method->name);
+       packet_put_string(mic.value, mic.length);
+       packet_send();
+
+       buffer_free(&b);
+       gss_release_buffer(&ms, &mic);
+
+       return (1);
+}
+
 #endif /* GSSAPI */
 
 int