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Diffstat (limited to 'sshconnect.c')
-rw-r--r--sshconnect.c147
1 files changed, 105 insertions, 42 deletions
diff --git a/sshconnect.c b/sshconnect.c
index bafdec95..1766de0c 100644
--- a/sshconnect.c
+++ b/sshconnect.c
@@ -13,7 +13,7 @@
*/
#include "includes.h"
-RCSID("$OpenBSD: sshconnect.c,v 1.107 2001/06/07 20:23:05 markus Exp $");
+RCSID("$OpenBSD: sshconnect.c,v 1.108 2001/06/23 02:34:31 markus Exp $");
#include <openssl/bn.h>
@@ -467,7 +467,10 @@ read_yes_or_no(const char *prompt, int defval)
while (1) {
fprintf(stderr, "%s", prompt);
if (fgets(buf, sizeof(buf), f) == NULL) {
- /* Print a newline (the prompt probably didn\'t have one). */
+ /*
+ * Print a newline (the prompt probably didn\'t have
+ * one).
+ */
fprintf(stderr, "\n");
strlcpy(buf, "no", sizeof buf);
}
@@ -493,12 +496,13 @@ read_yes_or_no(const char *prompt, int defval)
}
/*
- * check whether the supplied host key is valid, return only if ok.
+ * check whether the supplied host key is valid, return -1 if the key
+ * is not valid. the user_hostfile will not be updated if 'readonly' is true.
*/
-void
+int
check_host_key(char *host, struct sockaddr *hostaddr, Key *host_key,
- const char *user_hostfile, const char *system_hostfile)
+ int readonly, const char *user_hostfile, const char *system_hostfile)
{
Key *file_key;
char *type = key_type(host_key);
@@ -523,11 +527,13 @@ check_host_key(char *host, struct sockaddr *hostaddr, Key *host_key,
/** hostaddr == 0! */
switch (hostaddr->sa_family) {
case AF_INET:
- local = (ntohl(((struct sockaddr_in *)hostaddr)->sin_addr.s_addr) >> 24) == IN_LOOPBACKNET;
+ local = (ntohl(((struct sockaddr_in *)hostaddr)->
+ sin_addr.s_addr) >> 24) == IN_LOOPBACKNET;
salen = sizeof(struct sockaddr_in);
break;
case AF_INET6:
- local = IN6_IS_ADDR_LOOPBACK(&(((struct sockaddr_in6 *)hostaddr)->sin6_addr));
+ local = IN6_IS_ADDR_LOOPBACK(
+ &(((struct sockaddr_in6 *)hostaddr)->sin6_addr));
salen = sizeof(struct sockaddr_in6);
break;
default:
@@ -538,7 +544,7 @@ check_host_key(char *host, struct sockaddr *hostaddr, Key *host_key,
if (local && options.host_key_alias == NULL) {
debug("Forcing accepting of host key for "
"loopback/localhost.");
- return;
+ return 0;
}
/*
@@ -582,10 +588,12 @@ check_host_key(char *host, struct sockaddr *hostaddr, Key *host_key,
* hosts or in the systemwide list.
*/
host_file = user_hostfile;
- host_status = check_host_in_hostfile(host_file, host, host_key, file_key, &host_line);
+ host_status = check_host_in_hostfile(host_file, host, host_key,
+ file_key, &host_line);
if (host_status == HOST_NEW) {
host_file = system_hostfile;
- host_status = check_host_in_hostfile(host_file, host, host_key, file_key, &host_line);
+ host_status = check_host_in_hostfile(host_file, host, host_key,
+ file_key, &host_line);
}
/*
* Also perform check for the ip address, skip the check if we are
@@ -595,10 +603,12 @@ check_host_key(char *host, struct sockaddr *hostaddr, Key *host_key,
Key *ip_key = key_new(host_key->type);
ip_file = user_hostfile;
- ip_status = check_host_in_hostfile(ip_file, ip, host_key, ip_key, &ip_line);
+ ip_status = check_host_in_hostfile(ip_file, ip, host_key,
+ ip_key, &ip_line);
if (ip_status == HOST_NEW) {
ip_file = system_hostfile;
- ip_status = check_host_in_hostfile(ip_file, ip, host_key, ip_key, &ip_line);
+ ip_status = check_host_in_hostfile(ip_file, ip,
+ host_key, ip_key, &ip_line);
}
if (host_status == HOST_CHANGED &&
(ip_status != HOST_CHANGED || !key_equal(ip_key, file_key)))
@@ -617,32 +627,49 @@ check_host_key(char *host, struct sockaddr *hostaddr, Key *host_key,
host, type);
debug("Found key in %s:%d", host_file, host_line);
if (options.check_host_ip && ip_status == HOST_NEW) {
- if (!add_host_to_hostfile(user_hostfile, ip, host_key))
- log("Failed to add the %s host key for IP address '%.128s' to the list of known hosts (%.30s).",
- type, ip, user_hostfile);
- else
- log("Warning: Permanently added the %s host key for IP address '%.128s' to the list of known hosts.",
+ if (readonly)
+ log("%s host key for IP address "
+ "'%.128s' not in list of known hosts.",
type, ip);
+ else if (!add_host_to_hostfile(user_hostfile, ip,
+ host_key))
+ log("Failed to add the %s host key for IP "
+ "address '%.128s' to the list of known "
+ "hosts (%.30s).", type, ip, user_hostfile);
+ else
+ log("Warning: Permanently added the %s host "
+ "key for IP address '%.128s' to the list "
+ "of known hosts.", type, ip);
}
break;
case HOST_NEW:
+ if (readonly)
+ goto fail;
/* The host is new. */
if (options.strict_host_key_checking == 1) {
- /* User has requested strict host key checking. We will not add the host key
- automatically. The only alternative left is to abort. */
- fatal("No %s host key is known for %.200s and you have requested strict checking.", type, host);
+ /*
+ * User has requested strict host key checking. We
+ * will not add the host key automatically. The only
+ * alternative left is to abort.
+ */
+ error("No %s host key is known for %.200s and you "
+ "have requested strict checking.", type, host);
+ goto fail;
} else if (options.strict_host_key_checking == 2) {
/* The default */
char prompt[1024];
fp = key_fingerprint(host_key, SSH_FP_MD5, SSH_FP_HEX);
snprintf(prompt, sizeof(prompt),
- "The authenticity of host '%.200s (%s)' can't be established.\n"
+ "The authenticity of host '%.200s (%s)' can't be "
+ "established.\n"
"%s key fingerprint is %s.\n"
- "Are you sure you want to continue connecting (yes/no)? ",
- host, ip, type, fp);
+ "Are you sure you want to continue connecting "
+ "(yes/no)? ", host, ip, type, fp);
xfree(fp);
- if (!read_yes_or_no(prompt, -1))
- fatal("Aborted by user!");
+ if (!read_yes_or_no(prompt, -1)) {
+ log("Aborted by user!");
+ goto fail;
+ }
}
if (options.check_host_ip && ip_status == HOST_NEW) {
snprintf(hostline, sizeof(hostline), "%s,%s", host, ip);
@@ -650,13 +677,16 @@ check_host_key(char *host, struct sockaddr *hostaddr, Key *host_key,
} else
hostp = host;
- /* If not in strict mode, add the key automatically to the local known_hosts file. */
+ /*
+ * If not in strict mode, add the key automatically to the
+ * local known_hosts file.
+ */
if (!add_host_to_hostfile(user_hostfile, hostp, host_key))
- log("Failed to add the host to the list of known hosts (%.500s).",
- user_hostfile);
+ log("Failed to add the host to the list of known "
+ "hosts (%.500s).", user_hostfile);
else
- log("Warning: Permanently added '%.200s' (%s) to the list of known hosts.",
- hostp, type);
+ log("Warning: Permanently added '%.200s' (%s) to the "
+ "list of known hosts.", hostp, type);
break;
case HOST_CHANGED:
if (options.check_host_ip && host_ip_differ) {
@@ -698,8 +728,11 @@ check_host_key(char *host, struct sockaddr *hostaddr, Key *host_key,
* If strict host key checking is in use, the user will have
* to edit the key manually and we can only abort.
*/
- if (options.strict_host_key_checking)
- fatal("%s host key for %.200s has changed and you have requested strict checking.", type, host);
+ if (options.strict_host_key_checking) {
+ error("%s host key for %.200s has changed and you have "
+ "requested strict checking.", type, host);
+ goto fail;
+ }
/*
* If strict host key checking has not been requested, allow
@@ -707,20 +740,26 @@ check_host_key(char *host, struct sockaddr *hostaddr, Key *host_key,
* agent forwarding.
*/
if (options.password_authentication) {
- error("Password authentication is disabled to avoid trojan horses.");
+ error("Password authentication is disabled to avoid "
+ "man-in-the-middle attacks.");
options.password_authentication = 0;
}
if (options.forward_agent) {
- error("Agent forwarding is disabled to avoid trojan horses.");
+ error("Agent forwarding is disabled to avoid "
+ "man-in-the-middle attacks.");
options.forward_agent = 0;
}
if (options.forward_x11) {
- error("X11 forwarding is disabled to avoid trojan horses.");
+ error("X11 forwarding is disabled to avoid "
+ "man-in-the-middle attacks.");
options.forward_x11 = 0;
}
- if (options.num_local_forwards > 0 || options.num_remote_forwards > 0) {
- error("Port forwarding is disabled to avoid trojan horses.");
- options.num_local_forwards = options.num_remote_forwards = 0;
+ if (options.num_local_forwards > 0 ||
+ options.num_remote_forwards > 0) {
+ error("Port forwarding is disabled to avoid "
+ "man-in-the-middle attacks.");
+ options.num_local_forwards =
+ options.num_remote_forwards = 0;
}
/*
* XXX Should permit the user to change to use the new id.
@@ -741,15 +780,39 @@ check_host_key(char *host, struct sockaddr *hostaddr, Key *host_key,
log("Matching host key in %s:%d", host_file, host_line);
log("Offending key for IP in %s:%d", ip_file, ip_line);
if (options.strict_host_key_checking == 1) {
- fatal("Exiting, you have requested strict checking.");
+ error("Exiting, you have requested strict checking.");
+ goto fail;
} else if (options.strict_host_key_checking == 2) {
- if (!read_yes_or_no("Are you sure you want " \
- "to continue connecting (yes/no)? ", -1))
- fatal("Aborted by user!");
+ if (!read_yes_or_no("Are you sure you want "
+ "to continue connecting (yes/no)? ", -1)) {
+ log("Aborted by user!");
+ goto fail;
+ }
}
}
xfree(ip);
+ return 0;
+
+fail:
+ xfree(ip);
+ return -1;
+}
+
+int
+verify_host_key(char *host, struct sockaddr *hostaddr, Key *host_key)
+{
+ struct stat st;
+
+ /* return ok if the key can be found in an old keyfile */
+ if (stat(options.system_hostfile2, &st) == 0 ||
+ stat(options.user_hostfile2, &st) == 0) {
+ if (check_host_key(host, hostaddr, host_key, /*readonly*/ 1,
+ options.user_hostfile2, options.system_hostfile2) == 0)
+ return 0;
+ }
+ return check_host_key(host, hostaddr, host_key, /*readonly*/ 0,
+ options.user_hostfile, options.system_hostfile);
}
/*