X-Git-Url: http://andersk.mit.edu/gitweb/openssh.git/blobdiff_plain/9fd2a2156b8bd6b8cf563a70e3ac6a83cb729201..ca71903419fcc62ab0bec1f92f50788030a8d231:/ssh-agent.c

diff --git a/ssh-agent.c b/ssh-agent.c
index d4c008bb..61ea3458 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 1.103 2002/09/10 20:24:47 markus Exp $");
+RCSID("$OpenBSD: ssh-agent.c,v 1.110 2003/06/11 11:18:38 djm Exp $");
 
 #include <openssl/evp.h>
 #include <openssl/md5.h>
@@ -50,6 +50,8 @@ RCSID("$OpenBSD: ssh-agent.c,v 1.103 2002/09/10 20:24:47 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)
@@ -231,7 +261,7 @@ process_authentication_challenge1(SocketEntry *e)
 		/* The response is MD5 of decrypted challenge plus session id. */
 		len = BN_num_bytes(challenge);
 		if (len <= 0 || len > 32) {
-			log("process_authentication_challenge: bad challenge length %d", len);
+			logit("process_authentication_challenge: bad challenge length %d", len);
 			goto failure;
 		}
 		memset(buf, 0, 32);
@@ -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);
@@ -320,7 +350,7 @@ process_remove_identity(SocketEntry *e, int version)
 		buffer_get_bignum(&e->request, key->rsa->n);
 
 		if (bits != key_size(key))
-			log("Warning: identity keysize mismatch: actual %u, announced %u",
+			logit("Warning: identity keysize mismatch: actual %u, announced %u",
 			    key_size(key), bits);
 		break;
 	case 2:
@@ -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++;
@@ -533,13 +580,29 @@ static void
 process_add_smartcard_key (SocketEntry *e)
 {
 	char *sc_reader_id = NULL, *pin;
-	int i, version, success = 0;
+	int i, version, success = 0, death = 0, confirm = 0;
 	Key **keys, *k;
 	Identity *id;
 	Idtab *tab;
 
 	sc_reader_id = buffer_get_string(&e->request, NULL);
 	pin = buffer_get_string(&e->request, NULL);
+
+	while (buffer_len(&e->request)) {
+		switch (buffer_get_char(&e->request)) {
+		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;
+
 	keys = sc_get_keys(sc_reader_id, pin);
 	xfree(sc_reader_id);
 	xfree(pin);
@@ -556,7 +619,8 @@ process_add_smartcard_key (SocketEntry *e)
 			id = xmalloc(sizeof(Identity));
 			id->key = k;
 			id->comment = xstrdup("smartcard key");
-			id->death = 0;
+			id->death = death;
+			id->confirm = confirm;
 			TAILQ_INSERT_TAIL(&tab->idlist, id, next);
 			tab->nentries++;
 			success = 1;
@@ -700,6 +764,7 @@ process_message(SocketEntry *e)
 		break;
 #ifdef SMARTCARD
 	case SSH_AGENTC_ADD_SMARTCARD_KEY:
+	case SSH_AGENTC_ADD_SMARTCARD_KEY_CONSTRAINED:
 		process_add_smartcard_key(e);
 		break;
 	case SSH_AGENTC_REMOVE_SMARTCARD_KEY:
@@ -833,10 +898,10 @@ after_select(fd_set *readset, fd_set *writeset)
 					close(sock);
 					break;
 				}
-				if (getuid() != euid) {
+				if ((euid != 0) && (getuid() != euid)) {
 					error("uid mismatch: "
-					    "peer euid %d != uid %d",
-					    (int) euid, (int) getuid());
+					    "peer euid %u != uid %u",
+					    (u_int) euid, (u_int) getuid());
 					close(sock);
 					break;
 				}
@@ -914,7 +979,7 @@ check_parent_exists(int sig)
 		/* printf("Parent has died - Authentication agent exiting.\n"); */
 		cleanup_handler(sig); /* safe */
 	}
-	signal(SIGALRM, check_parent_exists);
+	mysignal(SIGALRM, check_parent_exists);
 	alarm(10);
 	errno = save_errno;
 }
@@ -930,13 +995,15 @@ 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 +1028,7 @@ 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 +1051,12 @@ 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 +1189,14 @@ 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 */
@@ -1133,7 +1211,7 @@ skip:
 	fatal_add_cleanup(cleanup_socket, NULL);
 	new_socket(AUTH_SOCKET, sock);
 	if (ac > 0) {
-		signal(SIGALRM, check_parent_exists);
+		mysignal(SIGALRM, check_parent_exists);
 		alarm(10);
 	}
 	idtab_init();