OpenSolaris Launch

1 files changed, 327 insertions, 0 deletions

diff --git a/usr/src/cmd/ssh/libssh/common/kexgssc.c b/usr/src/cmd/ssh/libssh/common/kexgssc.c
new file mode 100644
index 0000000000..815044733d
--- /dev/null
+++ b/usr/src/cmd/ssh/libssh/common/kexgssc.c
@@ -0,0 +1,327 @@
+/*
+ * Copyright (c) 2001-2003 Simon Wilkinson. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR `AS IS'' AND ANY EXPRESS OR
+ * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
+ * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
+ * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
+ * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+/*
+ * Copyright 2004 Sun Microsystems, Inc.  All rights reserved.
+ * Use is subject to license terms.
+ */
+
+#pragma ident	"%Z%%M%	%I%	%E% SMI"	
+
+
+#include "includes.h"
+
+#ifdef GSSAPI
+
+#include <openssl/crypto.h>
+#include <openssl/bn.h>
+
+#include "xmalloc.h"
+#include "buffer.h"
+#include "bufaux.h"
+#include "kex.h"
+#include "log.h"
+#include "packet.h"
+#include "dh.h"
+#include "canohost.h"
+#include "ssh2.h"
+#include "ssh-gss.h"
+
+extern char *xxx_host;
+
+Gssctxt *xxx_gssctxt;
+
+static void kexgss_verbose_cleanup(void *arg);
+
+void
+kexgss_client(Kex *kex)
+{
+	gss_buffer_desc gssbuf,send_tok,recv_tok, msg_tok;
+	gss_buffer_t token_ptr;
+	gss_OID mech = GSS_C_NULL_OID;
+	Gssctxt *ctxt = NULL;
+	OM_uint32 maj_status, min_status, smaj_status, smin_status;
+	unsigned int klen, kout;
+	DH *dh; 
+	BIGNUM *dh_server_pub = 0;
+	BIGNUM *shared_secret = 0;	
+	Key *server_host_key = NULL;
+	unsigned char *kbuf;
+	unsigned char *hash;
+	unsigned char *server_host_key_blob = NULL;
+	char *msg, *lang;
+	int type = 0;
+	int first = 1;
+	u_int sbloblen = 0;
+	u_int strlen;
+	
+	/* Map the negotiated kex name to a mech OID*/
+	ssh_gssapi_oid_of_kexname(kex->name, &mech);
+	if (mech == GSS_C_NULL_OID)
+		fatal("Couldn't match the negotiated GSS key exchange");
+
+	ssh_gssapi_build_ctx(&ctxt, 1, mech);
+
+	/* This code should match that in ssh_dh1_client */
+		
+	/* Step 1 - e is dh->pub_key */
+	dh = dh_new_group1();
+	dh_gen_key(dh, kex->we_need * 8);
+
+	/* This is f, we initialise it now to make life easier */
+    	dh_server_pub = BN_new();
+    	if (dh_server_pub == NULL) {
+    		fatal("dh_server_pub == NULL");
+    	}
+    		
+	token_ptr = GSS_C_NO_BUFFER;
+			 
+	recv_tok.value=NULL;
+	recv_tok.length=0;
+
+	do {
+		debug("Calling gss_init_sec_context");
+		
+		maj_status=ssh_gssapi_init_ctx(ctxt,
+					       xxx_host,
+					       kex->options.gss_deleg_creds,
+					       token_ptr,
+					       &send_tok);
+
+		if (GSS_ERROR(maj_status)) {
+			ssh_gssapi_error(ctxt, "performing GSS-API protected "
+				"SSHv2 key exchange");
+			(void) gss_release_buffer(&min_status, &send_tok);
+			packet_disconnect("A GSS-API error occurred during "
+				"GSS-API protected SSHv2 key exchange\n");
+		}
+
+		/* If we've got an old receive buffer get rid of it */
+		if (token_ptr != GSS_C_NO_BUFFER) {
+			/* We allocated recv_tok */
+			xfree(recv_tok.value);
+			recv_tok.value = NULL;
+			recv_tok.length = 0;
+			token_ptr = GSS_C_NO_BUFFER;
+		}
+		
+		if (maj_status == GSS_S_COMPLETE) {
+			/* If mutual state flag is not true, kex fails */
+			if (!(ctxt->flags & GSS_C_MUTUAL_FLAG)) {
+				fatal("Mutual authentication failed");
+			}
+			/* If integ avail flag is not true kex fails */
+			if (!(ctxt->flags & GSS_C_INTEG_FLAG)) {
+				fatal("Integrity check failed");
+			}
+		}
+		
+		/* If we have data to send, then the last message that we
+		 * received cannot have been a 'complete'. */
+		if (send_tok.length !=0) {
+			if (first) {
+				packet_start(SSH2_MSG_KEXGSS_INIT);
+				packet_put_string(send_tok.value,
+					  	  send_tok.length);
+				packet_put_bignum2(dh->pub_key);
+				first=0;
+			} else {
+				packet_start(SSH2_MSG_KEXGSS_CONTINUE);
+				packet_put_string(send_tok.value,
+						  send_tok.length);
+			}
+			(void) gss_release_buffer(&min_status, &send_tok);
+			packet_send();
+			packet_write_wait();
+
+			
+			/* If we've sent them data, they'd better be polite
+			 * and reply. */
+		
+next_packet:
+			/*
+			 * We need to catch connection closing w/o error
+			 * tokens or messages so we can tell the user
+			 * _something_ more useful than "Connection
+			 * closed by ..."
+			 *
+			 * We use a fatal cleanup function as that's
+			 * all, really, that we can do for now.
+			 */
+			fatal_add_cleanup(kexgss_verbose_cleanup, NULL);
+			type = packet_read();
+			fatal_remove_cleanup(kexgss_verbose_cleanup, NULL);
+			switch (type) {
+			case SSH2_MSG_KEXGSS_HOSTKEY:
+				debug("Received KEXGSS_HOSTKEY");
+				server_host_key_blob =
+					packet_get_string(&sbloblen);
+				server_host_key =
+					key_from_blob(server_host_key_blob,
+						sbloblen);
+				goto next_packet; /* there MUSt be another */
+				break;
+			case SSH2_MSG_KEXGSS_CONTINUE:
+				debug("Received GSSAPI_CONTINUE");
+				if (maj_status == GSS_S_COMPLETE) 
+					packet_disconnect("Protocol error: "
+						"received GSS-API context token"
+						" though the context was already"
+						" established");
+				recv_tok.value=packet_get_string(&strlen);
+				recv_tok.length=strlen; /* u_int vs. size_t */
+				break;
+			case SSH2_MSG_KEXGSS_COMPLETE:
+				debug("Received GSSAPI_COMPLETE");
+			        packet_get_bignum2(dh_server_pub);
+			    	msg_tok.value=packet_get_string(&strlen);
+				msg_tok.length=strlen; /* u_int vs. size_t */
+
+				/* Is there a token included? */
+				if (packet_get_char()) {
+					recv_tok.value=
+					    packet_get_string(&strlen);
+					recv_tok.length=strlen; /*u_int/size_t*/
+				}
+				if (recv_tok.length > 0 &&
+				    maj_status == GSS_S_COMPLETE) {
+					packet_disconnect("Protocol error: "
+						"received GSS-API context token"
+						" though the context was already"
+						" established");
+				} else if (recv_tok.length == 0 &&
+					maj_status == GSS_S_CONTINUE_NEEDED) {
+				   	/* No token included */
+					packet_disconnect("Protocol error: "
+						"did not receive expected "
+						"GSS-API context token");
+				}
+				break;
+			case SSH2_MSG_KEXGSS_ERROR:
+				smaj_status=packet_get_int();
+				smin_status=packet_get_int();
+				msg = packet_get_string(NULL);
+				lang = packet_get_string(NULL);
+				xfree(lang);
+				error("Server had a GSS-API error; the "
+					"connection will close (%d/%d):\n%s",
+					smaj_status, smin_status, msg);
+				error("Use the GssKeyEx option to disable "
+					"GSS-API key exchange and try again.");
+				packet_disconnect("The server had a GSS-API "
+					"error during GSS-API protected SSHv2 "
+					"key exchange\n");
+				break;
+			default:
+				packet_disconnect("Protocol error: "
+					"didn't expect packet type %d", type);
+			}
+			if (recv_tok.value)
+				token_ptr=&recv_tok;
+		} else {
+			/* No data, and not complete */
+			if (maj_status != GSS_S_COMPLETE) {
+				fatal("Not complete, and no token output");
+			}
+		}
+    	} while (maj_status == GSS_S_CONTINUE_NEEDED);
+    	
+    	/* We _must_ have received a COMPLETE message in reply from the 
+    	 * server, which will have set dh_server_pub and msg_tok */
+    	 
+    	if (type != SSH2_MSG_KEXGSS_COMPLETE)
+	    fatal("Expected SSH2_MSG_KEXGSS_COMPLETE never arrived");
+    	if (maj_status != GSS_S_COMPLETE)
+	    fatal("Internal error in GSS-API protected SSHv2 key exchange");
+    	 	    	
+	/* Check f in range [1, p-1] */
+        if (!dh_pub_is_valid(dh, dh_server_pub))
+                        packet_disconnect("bad server public DH value");
+                        
+        /* compute K=f^x mod p */
+        klen = DH_size(dh);
+        kbuf = xmalloc(klen);
+        kout = DH_compute_key(kbuf, dh_server_pub, dh);
+        
+        shared_secret = BN_new();
+        BN_bin2bn(kbuf,kout, shared_secret);
+        (void) memset(kbuf, 0, klen);
+        xfree(kbuf);
+        
+        /* The GSS hash is identical to the DH one */
+        hash = kex_dh_hash(
+ 	    kex->client_version_string,
+            kex->server_version_string,
+            buffer_ptr(&kex->my), buffer_len(&kex->my),
+            buffer_ptr(&kex->peer), buffer_len(&kex->peer),
+            server_host_key_blob, sbloblen, /* server host key */
+            dh->pub_key,	/* e */
+            dh_server_pub,	/* f */
+            shared_secret	/* K */
+        );
+        
+        gssbuf.value=hash;
+        gssbuf.length=20;
+        
+        /* Verify that H matches the token we just got. */
+	if ((maj_status = gss_verify_mic(&min_status,
+        	       		         ctxt->context,
+        	                         &gssbuf,
+        	                         &msg_tok,
+        	                         NULL))) {
+
+		packet_disconnect("Hash's MIC didn't verify");
+      	}	
+
+	if (server_host_key && kex->accept_host_key != NULL)
+		(void) kex->accept_host_key(server_host_key);
+        
+        DH_free(dh);
+
+	xxx_gssctxt = ctxt; /* for gss keyex w/ mic userauth */
+
+        /* save session id */
+        if (kex->session_id == NULL) {
+        	kex->session_id_len = 20;
+        	kex->session_id = xmalloc(kex->session_id_len);
+        	(void) memcpy(kex->session_id, hash, kex->session_id_len);
+        }
+        
+	kex_derive_keys(kex, hash, shared_secret);
+	BN_clear_free(shared_secret);
+        kex_finish(kex);
+}
+
+/* ARGSUSED */
+static
+void
+kexgss_verbose_cleanup(void *arg)
+{
+	error("The GSS-API protected key exchange has failed without "
+		"indication\nfrom the server, possibly due to misconfiguration "
+		"of the server.");
+	error("Use the GssKeyEx option to disable GSS-API key exchange "
+		"and try again.");
+}
+
+#endif /* GSSAPI */