From: dtucker@openbsd.org <dtucker@openbsd.org>
Date: Thu, 24 Jan 2019 17:00:29 +0000 (+0000)
Subject: upstream: Accept the host key fingerprint as a synonym for "yes"
X-Git-Tag: V_8_0_P1~65
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=05b9a466700b44d49492edc2aa415fc2e8913dfe;p=thirdparty%2Fopenssh-portable.git

upstream: Accept the host key fingerprint as a synonym for "yes"

when accepting an unknown host key.  This allows you to paste a fingerprint
obtained out of band into the yes/no prompt and have the client do the
comparison for you.  ok markus@ djm@

OpenBSD-Commit-ID: 3c47d10b9f43d3d345e044fd9ec09709583a2767
---

diff --git a/sshconnect.c b/sshconnect.c
index 1a5f6a4c8..955671b4e 100644
--- a/sshconnect.c
+++ b/sshconnect.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: sshconnect.c,v 1.311 2019/01/19 21:36:38 djm Exp $ */
+/* $OpenBSD: sshconnect.c,v 1.312 2019/01/24 17:00:29 dtucker Exp $ */
 /*
  * Author: Tatu Ylonen <ylo@cs.hut.fi>
  * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
@@ -563,22 +563,24 @@ ssh_connect(struct ssh *ssh, const char *host, struct addrinfo *addrs,
 
 /* defaults to 'no' */
 static int
-confirm(const char *prompt)
+confirm(const char *prompt, const char *fingerprint)
 {
 	const char *msg, *again = "Please type 'yes' or 'no': ";
+	const char *again_fp = "Please type 'yes', 'no' or the fingerprint: ";
 	char *p;
 	int ret = -1;
 
 	if (options.batch_mode)
 		return 0;
-	for (msg = prompt;;msg = again) {
+	for (msg = prompt;;msg = fingerprint ? again_fp : again) {
 		p = read_passphrase(msg, RP_ECHO);
 		if (p == NULL)
 			return 0;
 		p[strcspn(p, "\n")] = '\0';
 		if (p[0] == '\0' || strcasecmp(p, "no") == 0)
 			ret = 0;
-		else if (strcasecmp(p, "yes") == 0)
+		else if (strcasecmp(p, "yes") == 0 || (fingerprint != NULL &&
+		    strcasecmp(p, fingerprint) == 0))
 			ret = 1;
 		free(p);
 		if (ret != -1)
@@ -706,7 +708,7 @@ check_host_key(char *hostname, struct sockaddr *hostaddr, u_short port,
 	char msg[1024];
 	const char *type;
 	const struct hostkey_entry *host_found, *ip_found;
-	int len, cancelled_forwarding = 0;
+	int len, cancelled_forwarding = 0, confirmed;
 	int local = sockaddr_is_local(hostaddr);
 	int r, want_cert = sshkey_is_cert(host_key), host_ip_differ = 0;
 	int hostkey_trusted = 0; /* Known or explicitly accepted by user */
@@ -881,14 +883,15 @@ check_host_key(char *hostname, struct sockaddr *hostaddr, u_short port,
 			    "established%s\n"
 			    "%s key fingerprint is %s.%s%s\n%s"
 			    "Are you sure you want to continue connecting "
-			    "(yes/no)? ",
+			    "(yes/no/[fingerprint])? ",
 			    host, ip, msg1, type, fp,
 			    options.visual_host_key ? "\n" : "",
 			    options.visual_host_key ? ra : "",
 			    msg2);
 			free(ra);
+			confirmed = confirm(msg, fp);
 			free(fp);
-			if (!confirm(msg))
+			if (!confirmed)
 				goto fail;
 			hostkey_trusted = 1; /* user explicitly confirmed */
 		}
@@ -1082,7 +1085,7 @@ check_host_key(char *hostname, struct sockaddr *hostaddr, u_short port,
 		    SSH_STRICT_HOSTKEY_ASK) {
 			strlcat(msg, "\nAre you sure you want "
 			    "to continue connecting (yes/no)? ", sizeof(msg));
-			if (!confirm(msg))
+			if (!confirm(msg, NULL))
 				goto fail;
 		} else if (options.strict_host_key_checking !=
 		    SSH_STRICT_HOSTKEY_OFF) {