new option: HostKeyAlias: allows the user to record the host key

under a different name. This is useful for ssh tunneling over
forwarded connections or if you run multiple sshd's on different
ports on the same machine.

4 files changed, 37 insertions, 8 deletions

diff --git a/usr.bin/ssh/readconf.c b/usr.bin/ssh/readconf.c
index bb5277f1d93..59268f413c1 100644
--- a/usr.bin/ssh/readconf.c
+++ b/usr.bin/ssh/readconf.c
@@ -12,7 +12,7 @@
  */
 
 #include "includes.h"
-RCSID("$OpenBSD: readconf.c,v 1.51 2000/12/19 23:17:57 markus Exp $");
+RCSID("$OpenBSD: readconf.c,v 1.52 2000/12/27 12:30:19 markus Exp $");
 
 #include "ssh.h"
 #include "readconf.h"
@@ -103,7 +103,7 @@ typedef enum {
 	oCompressionLevel, oKeepAlives, oNumberOfPasswordPrompts, oTISAuthentication,
 	oUsePrivilegedPort, oLogLevel, oCiphers, oProtocol,
 	oGlobalKnownHostsFile2, oUserKnownHostsFile2, oPubkeyAuthentication,
-	oKbdInteractiveAuthentication, oKbdInteractiveDevices
+	oKbdInteractiveAuthentication, oKbdInteractiveDevices, oHostKeyAlias
 } OpCodes;
 
 /* Textual representations of the tokens. */
@@ -137,6 +137,7 @@ static struct {
 	{ "identityfile", oIdentityFile },
 	{ "identityfile2", oIdentityFile },			/* alias */
 	{ "hostname", oHostName },
+	{ "hostkeyalias", oHostKeyAlias },
 	{ "proxycommand", oProxyCommand },
 	{ "port", oPort },
 	{ "cipher", oCipher },
@@ -433,6 +434,10 @@ parse_string:
 		charptr = &options->hostname;
 		goto parse_string;
 
+	case oHostKeyAlias:
+		charptr = &options->host_key_alias;
+		goto parse_string;
+
 	case oProxyCommand:
 		charptr = &options->proxy_command;
 		string = xstrdup("");
@@ -687,6 +692,7 @@ initialize_options(Options * options)
 	options->protocol = SSH_PROTO_UNKNOWN;
 	options->num_identity_files = 0;
 	options->hostname = NULL;
+	options->host_key_alias = NULL;
 	options->proxy_command = NULL;
 	options->user = NULL;
 	options->escape_char = -1;
@@ -800,4 +806,5 @@ fill_default_options(Options * options)
 	/* options->proxy_command should not be set by default */
 	/* options->user will be set in the main program if appropriate */
 	/* options->hostname will be set in the main program if appropriate */
+	/* options->host_key_alias should not be set by default */
 }
diff --git a/usr.bin/ssh/readconf.h b/usr.bin/ssh/readconf.h
index 85d937d8716..08ff70839e8 100644
--- a/usr.bin/ssh/readconf.h
+++ b/usr.bin/ssh/readconf.h
@@ -11,7 +11,7 @@
  * called by a name other than "ssh" or "Secure Shell".
  */
 
-/* RCSID("$OpenBSD: readconf.h,v 1.23 2000/11/12 19:50:37 markus Exp $"); */
+/* RCSID("$OpenBSD: readconf.h,v 1.24 2000/12/27 12:30:20 markus Exp $"); */
 
 #ifndef READCONF_H
 #define READCONF_H
@@ -69,6 +69,7 @@ typedef struct {
 	char   *ciphers;	/* SSH2 ciphers in order of preference. */
 	int	protocol;	/* Protocol in order of preference. */
 	char   *hostname;	/* Real host to connect. */
+	char   *host_key_alias;	/* hostname alias for .ssh/known_hosts */
 	char   *proxy_command;	/* Proxy command for connecting the host. */
 	char   *user;		/* User to log in as. */
 	int     escape_char;	/* Escape character; -2 = none */
diff --git a/usr.bin/ssh/ssh.1 b/usr.bin/ssh/ssh.1
index d830cfeb2b3..40cb6dfa8b4 100644
--- a/usr.bin/ssh/ssh.1
+++ b/usr.bin/ssh/ssh.1
@@ -34,7 +34,7 @@
 .\" (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 .\" THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 .\"
-.\" $OpenBSD: ssh.1,v 1.73 2000/12/27 11:51:53 markus Exp $
+.\" $OpenBSD: ssh.1,v 1.74 2000/12/27 12:30:20 markus Exp $
 .Dd September 25, 1999
 .Dt SSH 1
 .Os
@@ -746,6 +746,12 @@ The default is
 .It Cm GlobalKnownHostsFile
 Specifies a file to use instead of
 .Pa /etc/ssh_known_hosts .
+.It Cm HostKeyAlias
+Specifies an alias that should be used instead of the
+real host name when looking up or saving the host key
+the kown_hosts files.
+This option is useful for tunneling ssh connection
+or if you have multiple servers running on a single host.
 .It Cm HostName
 Specifies the real host name to log into.
 This can be used to specify nicknames or abbreviations for hosts.
diff --git a/usr.bin/ssh/sshconnect.c b/usr.bin/ssh/sshconnect.c
index a894c7fc166..5672ff939ff 100644
--- a/usr.bin/ssh/sshconnect.c
+++ b/usr.bin/ssh/sshconnect.c
@@ -13,7 +13,7 @@
  */
 
 #include "includes.h"
-RCSID("$OpenBSD: sshconnect.c,v 1.85 2000/12/21 15:10:17 markus Exp $");
+RCSID("$OpenBSD: sshconnect.c,v 1.86 2000/12/27 12:30:20 markus Exp $");
 
 #include <openssl/bn.h>
 #include <openssl/dsa.h>
@@ -491,8 +491,13 @@ check_host_key(char *host, struct sockaddr *hostaddr, Key *host_key,
 		break;
 	}
 	if (local) {
-		debug("Forcing accepting of host key for loopback/localhost.");
-		return;
+		if (options.host_key_alias == NULL) {
+			debug("Forcing accepting of host key for "
+			    "loopback/localhost.");
+			return;
+		}
+		if (options.check_host_ip)
+			options.check_host_ip = 0;
 	}
 
 	/*
@@ -504,7 +509,7 @@ check_host_key(char *host, struct sockaddr *hostaddr, Key *host_key,
 
 	if (options.proxy_command == NULL) {
 		if (getnameinfo(hostaddr, hostaddr->sa_len, ntop, sizeof(ntop),
-				NULL, 0, NI_NUMERICHOST) != 0)
+		    NULL, 0, NI_NUMERICHOST) != 0)
 			fatal("check_host_key: getnameinfo failed");
 		ip = xstrdup(ntop);
 	} else {
@@ -512,6 +517,16 @@ check_host_key(char *host, struct sockaddr *hostaddr, Key *host_key,
 	}
 
 	/*
+	 * Allow the user to record the key under a different name. This is
+	 * useful for ssh tunneling over forwarded connections or if you run
+	 * multiple sshd's on different ports on the same machine.
+	 */
+	if (options.host_key_alias != NULL) {
+		host = options.host_key_alias;
+		debug("using hostkeyalias: %s", host);
+	}
+
+	/*
 	 * Store the host key from the known host file in here so that we can
 	 * compare it with the key for the IP address.
 	 */