1 files changed, 70 insertions, 9 deletions

diff --git a/ssh-agent.c b/ssh-agent.c
index cca720ee2..eb593de73 100644
--- a/ssh-agent.c
+++ b/ssh-agent.c
@@ -35,7 +35,7 @@
 
 #include "includes.h"
 #include "openbsd-compat/sys-queue.h"
-RCSID("$OpenBSD: ssh-agent.c,v 1.105 2002/10/01 20:34:12 markus Exp $");
+RCSID("$OpenBSD: ssh-agent.c,v 1.108 2003/03/13 11:44:50 markus Exp $");
 
 #include <openssl/evp.h>
 #include <openssl/md5.h>
@@ -50,6 +50,8 @@ RCSID("$OpenBSD: ssh-agent.c,v 1.105 2002/10/01 20:34:12 markus Exp $");
 #include "authfd.h"
 #include "compat.h"
 #include "log.h"
+#include "readpass.h"
+#include "misc.h"
 
 #ifdef SMARTCARD
 #include "scard.h"
@@ -77,6 +79,7 @@ typedef struct identity {
         Key *key;
         char *comment;
         u_int death;
+        u_int confirm;
 } Identity;
 
 typedef struct {
@@ -106,6 +109,9 @@ extern char *__progname;
 char *__progname;
 #endif
 
+/* Default lifetime (0 == forever) */
+static int lifetime = 0;
+
 static void
 close_socket(SocketEntry *e)
 {
@@ -159,6 +165,30 @@ lookup_identity(Key *key, int version)
         return (NULL);
 }
 
+/* Check confirmation of keysign request */
+static int
+confirm_key(Identity *id)
+{
+        char *p, prompt[1024];
+        int ret = -1;
+
+        p = key_fingerprint(id->key, SSH_FP_MD5, SSH_FP_HEX);
+        snprintf(prompt, sizeof(prompt), "Allow use of key %s?\n"
+            "Key fingerprint %s.", id->comment, p);
+        xfree(p);
+        p = read_passphrase(prompt, RP_ALLOW_EOF);
+        if (p != NULL) {
+                /*
+                 * Accept empty responses and responses consisting 
+                 * of the word "yes" as affirmative.
+                 */
+                if (*p == '\0' || *p == '\n' || strcasecmp(p, "yes") == 0)
+                        ret = 0;
+                xfree(p);
+        }
+        return (ret);
+}
+
 /* send list of supported public keys to 'client' */
 static void
 process_request_identities(SocketEntry *e, int version)
@@ -222,7 +252,7 @@ process_authentication_challenge1(SocketEntry *e)
                 goto failure;
 
         id = lookup_identity(key, 1);
-        if (id != NULL) {
+        if (id != NULL && (!id->confirm || confirm_key(id) == 0)) {
                 Key *private = id->key;
                 /* Decrypt the challenge using the private key. */
                 if (rsa_private_decrypt(challenge, challenge, private->rsa) <= 0)
@@ -282,7 +312,7 @@ process_sign_request2(SocketEntry *e)
         key = key_from_blob(blob, blen);
         if (key != NULL) {
                 Identity *id = lookup_identity(key, 2);
-                if (id != NULL)
+                if (id != NULL && (!id->confirm || confirm_key(id) == 0))
                         ok = key_sign(id->key, &signature, &slen, data, dlen);
         }
         key_free(key);
@@ -402,7 +432,7 @@ static void
 process_add_identity(SocketEntry *e, int version)
 {
         Idtab *tab = idtab_lookup(version);
-        int type, success = 0, death = 0;
+        int type, success = 0, death = 0, confirm = 0;
         char *type_name, *comment;
         Key *k = NULL;
 
@@ -453,6 +483,17 @@ process_add_identity(SocketEntry *e, int version)
                 }
                 break;
         }
+        /* enable blinding */
+        switch (k->type) {
+        case KEY_RSA:
+        case KEY_RSA1:
+                if (RSA_blinding_on(k->rsa, NULL) != 1) {
+                        error("process_add_identity: RSA_blinding_on failed");
+                        key_free(k);
+                        goto send;
+                }
+                break;
+        }
         comment = buffer_get_string(&e->request, NULL);
         if (k == NULL) {
                 xfree(comment);
@@ -464,15 +505,21 @@ process_add_identity(SocketEntry *e, int version)
                 case SSH_AGENT_CONSTRAIN_LIFETIME:
                         death = time(NULL) + buffer_get_int(&e->request);
                         break;
+                case SSH_AGENT_CONSTRAIN_CONFIRM:
+                        confirm = 1;
+                        break;
                 default:
                         break;
                 }
         }
+        if (lifetime && !death)
+                death = time(NULL) + lifetime;
         if (lookup_identity(k, version) == NULL) {
                 Identity *id = xmalloc(sizeof(Identity));
                 id->key = k;
                 id->comment = comment;
                 id->death = death;
+                id->confirm = confirm;
                 TAILQ_INSERT_TAIL(&tab->idlist, id, next);
                 /* Increment the number of identities. */
                 tab->nentries++;
@@ -557,6 +604,7 @@ process_add_smartcard_key (SocketEntry *e)
                         id->key = k;
                         id->comment = xstrdup("smartcard key");
                         id->death = 0;
+                        id->confirm = 0;
                         TAILQ_INSERT_TAIL(&tab->idlist, id, next);
                         tab->nentries++;
                         success = 1;
@@ -930,13 +978,15 @@ usage(void)
         fprintf(stderr, "  -k          Kill the current agent.\n");
         fprintf(stderr, "  -d          Debug mode.\n");
         fprintf(stderr, "  -a socket   Bind agent socket to given name.\n");
+        fprintf(stderr, "  -t life     Default identity lifetime (seconds).\n");
         exit(1);
 }
 
 int
 main(int ac, char **av)
 {
-        int sock, c_flag = 0, d_flag = 0, k_flag = 0, s_flag = 0, ch, nalloc;
+        int c_flag = 0, d_flag = 0, k_flag = 0, s_flag = 0;
+        int sock, fd,  ch, nalloc;
         char *shell, *format, *pidstr, *agentsocket = NULL;
         fd_set *readsetp = NULL, *writesetp = NULL;
         struct sockaddr_un sunaddr;
@@ -961,7 +1011,7 @@ main(int ac, char **av)
         init_rng();
         seed_rng();
 
-        while ((ch = getopt(ac, av, "cdksa:")) != -1) {
+        while ((ch = getopt(ac, av, "cdksa:t:")) != -1) {
                 switch (ch) {
                 case 'c':
                         if (s_flag)
@@ -984,6 +1034,12 @@ main(int ac, char **av)
                 case 'a':
                         agentsocket = optarg;
                         break;
+                case 't':
+                        if ((lifetime = convtime(optarg)) == -1) {
+                                fprintf(stderr, "Invalid lifetime\n");
+                                usage();
+                        }
+                        break;
                 default:
                         usage();
                 }
@@ -1116,9 +1172,14 @@ main(int ac, char **av)
         }
 
         (void)chdir("/");
-        close(0);
-        close(1);
-        close(2);
+        if ((fd = open(_PATH_DEVNULL, O_RDWR, 0)) != -1) {
+                /* XXX might close listen socket */
+                (void)dup2(fd, STDIN_FILENO);
+                (void)dup2(fd, STDOUT_FILENO);
+                (void)dup2(fd, STDERR_FILENO);
+                if (fd > 2)
+                        close(fd);
+        }
 
 #ifdef HAVE_SETRLIMIT
         /* deny core dumps, since memory contains unencrypted private keys */