-/* $OpenBSD: ssh-agent.c,v 1.15 1999/10/28 08:43:10 markus Exp $ */
-
+/* $OpenBSD: ssh-agent.c,v 1.162 2009/09/01 14:43:17 djm Exp $ */
/*
+ * Author: Tatu Ylonen <ylo@cs.hut.fi>
+ * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
+ * All rights reserved
+ * The authentication agent program.
+ *
+ * As far as I am concerned, the code I have written for this software
+ * can be used freely for any purpose. Any derived versions of this
+ * software must be clearly marked as such, and if the derived work is
+ * incompatible with the protocol description in the RFC file, it must be
+ * called by a name other than "ssh" or "Secure Shell".
+ *
+ * Copyright (c) 2000, 2001 Markus Friedl. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
+ * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
+ * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
+ * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
+ * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
-ssh-agent.c
-
-Author: Tatu Ylonen <ylo@cs.hut.fi>
-
-Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
- All rights reserved
-
-Created: Wed Mar 29 03:46:59 1995 ylo
+#include "includes.h"
-The authentication agent program.
+#include <sys/types.h>
+#include <sys/param.h>
+#include <sys/resource.h>
+#include <sys/stat.h>
+#include <sys/socket.h>
+#ifdef HAVE_SYS_TIME_H
+# include <sys/time.h>
+#endif
+#ifdef HAVE_SYS_UN_H
+# include <sys/un.h>
+#endif
+#include "openbsd-compat/sys-queue.h"
-*/
+#include <openssl/evp.h>
+#include <openssl/md5.h>
+#include "openbsd-compat/openssl-compat.h"
-#include "config.h"
-#include "includes.h"
-RCSID("$OpenBSD: ssh-agent.c,v 1.15 1999/10/28 08:43:10 markus Exp $");
+#include <errno.h>
+#include <fcntl.h>
+#ifdef HAVE_PATHS_H
+# include <paths.h>
+#endif
+#include <signal.h>
+#include <stdarg.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <time.h>
+#include <string.h>
+#include <unistd.h>
+#include "xmalloc.h"
#include "ssh.h"
#include "rsa.h"
-#include "authfd.h"
#include "buffer.h"
-#include "bufaux.h"
-#include "xmalloc.h"
-#include "packet.h"
-#include "getput.h"
-#include "mpaux.h"
+#include "key.h"
+#include "authfd.h"
+#include "compat.h"
+#include "log.h"
+#include "misc.h"
-#ifdef HAVE_OPENSSL
-#include <openssl/md5.h>
+#ifdef SMARTCARD
+#include "scard.h"
#endif
-#ifdef HAVE_SSL
-#include <ssl/md5.h>
+
+#if defined(HAVE_SYS_PRCTL_H)
+#include <sys/prctl.h> /* For prctl() and PR_SET_DUMPABLE */
#endif
-typedef struct
-{
- int fd;
- enum { AUTH_UNUSED, AUTH_SOCKET, AUTH_CONNECTION } type;
- Buffer input;
- Buffer output;
+typedef enum {
+ AUTH_UNUSED,
+ AUTH_SOCKET,
+ AUTH_CONNECTION
+} sock_type;
+
+typedef struct {
+ int fd;
+ sock_type type;
+ Buffer input;
+ Buffer output;
+ Buffer request;
} SocketEntry;
-unsigned int sockets_alloc = 0;
+u_int sockets_alloc = 0;
SocketEntry *sockets = NULL;
-typedef struct
-{
- RSA *key;
- char *comment;
+typedef struct identity {
+ TAILQ_ENTRY(identity) next;
+ Key *key;
+ char *comment;
+ u_int death;
+ u_int confirm;
} Identity;
-unsigned int num_identities = 0;
-Identity *identities = NULL;
+typedef struct {
+ int nentries;
+ TAILQ_HEAD(idqueue, identity) idlist;
+} Idtab;
+
+/* private key table, one per protocol version */
+Idtab idtable[3];
int max_fd = 0;
/* pid of shell == parent of agent */
-int parent_pid = -1;
+pid_t parent_pid = -1;
+u_int parent_alive_interval = 0;
/* pathname and directory for AUTH_SOCKET */
-char socket_name[1024];
-char socket_dir[1024];
+char socket_name[MAXPATHLEN];
+char socket_dir[MAXPATHLEN];
-void
-process_request_identity(SocketEntry *e)
+/* locking */
+int locked = 0;
+char *lock_passwd = NULL;
+
+extern char *__progname;
+
+/* Default lifetime (0 == forever) */
+static int lifetime = 0;
+
+static void
+close_socket(SocketEntry *e)
{
- Buffer msg;
- int i;
-
- buffer_init(&msg);
- buffer_put_char(&msg, SSH_AGENT_RSA_IDENTITIES_ANSWER);
- buffer_put_int(&msg, num_identities);
- for (i = 0; i < num_identities; i++)
- {
- buffer_put_int(&msg, BN_num_bits(identities[i].key->n));
- buffer_put_bignum(&msg, identities[i].key->e);
- buffer_put_bignum(&msg, identities[i].key->n);
- buffer_put_string(&msg, identities[i].comment,
- strlen(identities[i].comment));
- }
- buffer_put_int(&e->output, buffer_len(&msg));
- buffer_append(&e->output, buffer_ptr(&msg), buffer_len(&msg));
- buffer_free(&msg);
+ close(e->fd);
+ e->fd = -1;
+ e->type = AUTH_UNUSED;
+ buffer_free(&e->input);
+ buffer_free(&e->output);
+ buffer_free(&e->request);
}
-void
-process_authentication_challenge(SocketEntry *e)
+static void
+idtab_init(void)
{
- int i, pub_bits, len;
- BIGNUM *pub_e, *pub_n, *challenge;
- Buffer msg;
- MD5_CTX md;
- unsigned char buf[32], mdbuf[16], session_id[16];
- unsigned int response_type;
-
- buffer_init(&msg);
- pub_e = BN_new();
- pub_n = BN_new();
- challenge = BN_new();
- pub_bits = buffer_get_int(&e->input);
- buffer_get_bignum(&e->input, pub_e);
- buffer_get_bignum(&e->input, pub_n);
- buffer_get_bignum(&e->input, challenge);
- if (buffer_len(&e->input) == 0)
- {
- /* Compatibility code for old servers. */
- memset(session_id, 0, 16);
- response_type = 0;
- }
- else
- {
- /* New code. */
- buffer_get(&e->input, (char *)session_id, 16);
- response_type = buffer_get_int(&e->input);
- }
- for (i = 0; i < num_identities; i++)
- if (pub_bits == BN_num_bits(identities[i].key->n) &&
- BN_cmp(pub_e, identities[i].key->e) == 0 &&
- BN_cmp(pub_n, identities[i].key->n) == 0)
- {
- /* Decrypt the challenge using the private key. */
- rsa_private_decrypt(challenge, challenge, identities[i].key);
-
- /* Compute the desired response. */
- switch (response_type)
- {
- case 0: /* As of protocol 1.0 */
- /* This response type is no longer supported. */
- log("Compatibility with ssh protocol 1.0 no longer supported.");
- buffer_put_char(&msg, SSH_AGENT_FAILURE);
- goto send;
-
- case 1: /* As of protocol 1.1 */
- /* The response is MD5 of decrypted challenge plus session id. */
- len = BN_num_bytes(challenge);
- assert(len <= 32 && len);
- memset(buf, 0, 32);
- BN_bn2bin(challenge, buf + 32 - len);
- MD5_Init(&md);
- MD5_Update(&md, buf, 32);
- MD5_Update(&md, session_id, 16);
- MD5_Final(mdbuf, &md);
- break;
-
- default:
- fatal("process_authentication_challenge: bad response_type %d",
- response_type);
- break;
- }
-
- /* Send the response. */
- buffer_put_char(&msg, SSH_AGENT_RSA_RESPONSE);
- for (i = 0; i < 16; i++)
- buffer_put_char(&msg, mdbuf[i]);
-
- goto send;
- }
- /* Unknown identity. Send failure. */
- buffer_put_char(&msg, SSH_AGENT_FAILURE);
- send:
- buffer_put_int(&e->output, buffer_len(&msg));
- buffer_append(&e->output, buffer_ptr(&msg),
- buffer_len(&msg));
- buffer_free(&msg);
- BN_clear_free(pub_e);
- BN_clear_free(pub_n);
- BN_clear_free(challenge);
+ int i;
+
+ for (i = 0; i <=2; i++) {
+ TAILQ_INIT(&idtable[i].idlist);
+ idtable[i].nentries = 0;
+ }
}
-void
-process_remove_identity(SocketEntry *e)
+/* return private key table for requested protocol version */
+static Idtab *
+idtab_lookup(int version)
{
- unsigned int bits;
- unsigned int i;
- BIGNUM *dummy, *n;
-
- dummy = BN_new();
- n = BN_new();
-
- /* Get the key from the packet. */
- bits = buffer_get_int(&e->input);
- buffer_get_bignum(&e->input, dummy);
- buffer_get_bignum(&e->input, n);
-
- /* Check if we have the key. */
- for (i = 0; i < num_identities; i++)
- if (BN_cmp(identities[i].key->n, n) == 0)
- {
- /* We have this key. Free the old key. Since we don\'t want to leave
- empty slots in the middle of the array, we actually free the
- key there and copy data from the last entry. */
- RSA_free(identities[i].key);
- xfree(identities[i].comment);
- if (i < num_identities - 1)
- identities[i] = identities[num_identities - 1];
- num_identities--;
- BN_clear_free(dummy);
- BN_clear_free(n);
+ if (version < 1 || version > 2)
+ fatal("internal error, bad protocol version %d", version);
+ return &idtable[version];
+}
- /* Send success. */
- buffer_put_int(&e->output, 1);
- buffer_put_char(&e->output, SSH_AGENT_SUCCESS);
- return;
- }
- /* We did not have the key. */
- BN_clear(dummy);
- BN_clear(n);
-
- /* Send failure. */
- buffer_put_int(&e->output, 1);
- buffer_put_char(&e->output, SSH_AGENT_FAILURE);
+static void
+free_identity(Identity *id)
+{
+ key_free(id->key);
+ xfree(id->comment);
+ xfree(id);
}
-/* Removes all identities from the agent. */
+/* return matching private key for given public key */
+static Identity *
+lookup_identity(Key *key, int version)
+{
+ Identity *id;
-void
-process_remove_all_identities(SocketEntry *e)
+ Idtab *tab = idtab_lookup(version);
+ TAILQ_FOREACH(id, &tab->idlist, next) {
+ if (key_equal(key, id->key))
+ return (id);
+ }
+ return (NULL);
+}
+
+/* Check confirmation of keysign request */
+static int
+confirm_key(Identity *id)
{
- unsigned int i;
-
- /* Loop over all identities and clear the keys. */
- for (i = 0; i < num_identities; i++)
- {
- RSA_free(identities[i].key);
- xfree(identities[i].comment);
- }
-
- /* Mark that there are no identities. */
- num_identities = 0;
-
- /* Send success. */
- buffer_put_int(&e->output, 1);
- buffer_put_char(&e->output, SSH_AGENT_SUCCESS);
- return;
+ char *p;
+ int ret = -1;
+
+ p = key_fingerprint(id->key, SSH_FP_MD5, SSH_FP_HEX);
+ if (ask_permission("Allow use of key %s?\nKey fingerprint %s.",
+ id->comment, p))
+ ret = 0;
+ xfree(p);
+
+ return (ret);
}
-/* Adds an identity to the agent. */
+/* send list of supported public keys to 'client' */
+static void
+process_request_identities(SocketEntry *e, int version)
+{
+ Idtab *tab = idtab_lookup(version);
+ Identity *id;
+ Buffer msg;
+
+ buffer_init(&msg);
+ buffer_put_char(&msg, (version == 1) ?
+ SSH_AGENT_RSA_IDENTITIES_ANSWER : SSH2_AGENT_IDENTITIES_ANSWER);
+ buffer_put_int(&msg, tab->nentries);
+ TAILQ_FOREACH(id, &tab->idlist, next) {
+ if (id->key->type == KEY_RSA1) {
+ buffer_put_int(&msg, BN_num_bits(id->key->rsa->n));
+ buffer_put_bignum(&msg, id->key->rsa->e);
+ buffer_put_bignum(&msg, id->key->rsa->n);
+ } else {
+ u_char *blob;
+ u_int blen;
+ key_to_blob(id->key, &blob, &blen);
+ buffer_put_string(&msg, blob, blen);
+ xfree(blob);
+ }
+ buffer_put_cstring(&msg, id->comment);
+ }
+ buffer_put_int(&e->output, buffer_len(&msg));
+ buffer_append(&e->output, buffer_ptr(&msg), buffer_len(&msg));
+ buffer_free(&msg);
+}
-void
-process_add_identity(SocketEntry *e)
+/* ssh1 only */
+static void
+process_authentication_challenge1(SocketEntry *e)
+{
+ u_char buf[32], mdbuf[16], session_id[16];
+ u_int response_type;
+ BIGNUM *challenge;
+ Identity *id;
+ int i, len;
+ Buffer msg;
+ MD5_CTX md;
+ Key *key;
+
+ buffer_init(&msg);
+ key = key_new(KEY_RSA1);
+ if ((challenge = BN_new()) == NULL)
+ fatal("process_authentication_challenge1: BN_new failed");
+
+ (void) buffer_get_int(&e->request); /* ignored */
+ buffer_get_bignum(&e->request, key->rsa->e);
+ buffer_get_bignum(&e->request, key->rsa->n);
+ buffer_get_bignum(&e->request, challenge);
+
+ /* Only protocol 1.1 is supported */
+ if (buffer_len(&e->request) == 0)
+ goto failure;
+ buffer_get(&e->request, session_id, 16);
+ response_type = buffer_get_int(&e->request);
+ if (response_type != 1)
+ goto failure;
+
+ id = lookup_identity(key, 1);
+ 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)
+ goto failure;
+
+ /* The response is MD5 of decrypted challenge plus session id. */
+ len = BN_num_bytes(challenge);
+ if (len <= 0 || len > 32) {
+ logit("process_authentication_challenge: bad challenge length %d", len);
+ goto failure;
+ }
+ memset(buf, 0, 32);
+ BN_bn2bin(challenge, buf + 32 - len);
+ MD5_Init(&md);
+ MD5_Update(&md, buf, 32);
+ MD5_Update(&md, session_id, 16);
+ MD5_Final(mdbuf, &md);
+
+ /* Send the response. */
+ buffer_put_char(&msg, SSH_AGENT_RSA_RESPONSE);
+ for (i = 0; i < 16; i++)
+ buffer_put_char(&msg, mdbuf[i]);
+ goto send;
+ }
+
+failure:
+ /* Unknown identity or protocol error. Send failure. */
+ buffer_put_char(&msg, SSH_AGENT_FAILURE);
+send:
+ buffer_put_int(&e->output, buffer_len(&msg));
+ buffer_append(&e->output, buffer_ptr(&msg), buffer_len(&msg));
+ key_free(key);
+ BN_clear_free(challenge);
+ buffer_free(&msg);
+}
+
+/* ssh2 only */
+static void
+process_sign_request2(SocketEntry *e)
+{
+ u_char *blob, *data, *signature = NULL;
+ u_int blen, dlen, slen = 0;
+ extern int datafellows;
+ int odatafellows;
+ int ok = -1, flags;
+ Buffer msg;
+ Key *key;
+
+ datafellows = 0;
+
+ blob = buffer_get_string(&e->request, &blen);
+ data = buffer_get_string(&e->request, &dlen);
+
+ flags = buffer_get_int(&e->request);
+ odatafellows = datafellows;
+ if (flags & SSH_AGENT_OLD_SIGNATURE)
+ datafellows = SSH_BUG_SIGBLOB;
+
+ key = key_from_blob(blob, blen);
+ if (key != NULL) {
+ Identity *id = lookup_identity(key, 2);
+ if (id != NULL && (!id->confirm || confirm_key(id) == 0))
+ ok = key_sign(id->key, &signature, &slen, data, dlen);
+ key_free(key);
+ }
+ buffer_init(&msg);
+ if (ok == 0) {
+ buffer_put_char(&msg, SSH2_AGENT_SIGN_RESPONSE);
+ buffer_put_string(&msg, signature, slen);
+ } else {
+ buffer_put_char(&msg, SSH_AGENT_FAILURE);
+ }
+ buffer_put_int(&e->output, buffer_len(&msg));
+ buffer_append(&e->output, buffer_ptr(&msg),
+ buffer_len(&msg));
+ buffer_free(&msg);
+ xfree(data);
+ xfree(blob);
+ if (signature != NULL)
+ xfree(signature);
+ datafellows = odatafellows;
+}
+
+/* shared */
+static void
+process_remove_identity(SocketEntry *e, int version)
{
- RSA *k;
- int i;
- BIGNUM *aux;
- BN_CTX *ctx;
-
- if (num_identities == 0)
- identities = xmalloc(sizeof(Identity));
- else
- identities = xrealloc(identities, (num_identities + 1) * sizeof(Identity));
-
- identities[num_identities].key = RSA_new();
- k = identities[num_identities].key;
- buffer_get_int(&e->input); /* bits */
- k->n = BN_new();
- buffer_get_bignum(&e->input, k->n);
- k->e = BN_new();
- buffer_get_bignum(&e->input, k->e);
- k->d = BN_new();
- buffer_get_bignum(&e->input, k->d);
- k->iqmp = BN_new();
- buffer_get_bignum(&e->input, k->iqmp);
- /* SSH and SSL have p and q swapped */
- k->q = BN_new();
- buffer_get_bignum(&e->input, k->q); /* p */
- k->p = BN_new();
- buffer_get_bignum(&e->input, k->p); /* q */
-
- /* Generate additional parameters */
- aux = BN_new();
- ctx = BN_CTX_new();
-
- BN_sub(aux, k->q, BN_value_one());
- k->dmq1 = BN_new();
- BN_mod(k->dmq1, k->d, aux, ctx);
-
- BN_sub(aux, k->p, BN_value_one());
- k->dmp1 = BN_new();
- BN_mod(k->dmp1, k->d, aux, ctx);
-
- BN_clear_free(aux);
- BN_CTX_free(ctx);
-
- identities[num_identities].comment = buffer_get_string(&e->input, NULL);
-
- /* Check if we already have the key. */
- for (i = 0; i < num_identities; i++)
- if (BN_cmp(identities[i].key->n, k->n) == 0)
- {
- /* We already have this key. Clear and free the new data and
- return success. */
- RSA_free(k);
- xfree(identities[num_identities].comment);
+ u_int blen, bits;
+ int success = 0;
+ Key *key = NULL;
+ u_char *blob;
+
+ switch (version) {
+ case 1:
+ key = key_new(KEY_RSA1);
+ bits = buffer_get_int(&e->request);
+ buffer_get_bignum(&e->request, key->rsa->e);
+ buffer_get_bignum(&e->request, key->rsa->n);
+
+ if (bits != key_size(key))
+ logit("Warning: identity keysize mismatch: actual %u, announced %u",
+ key_size(key), bits);
+ break;
+ case 2:
+ blob = buffer_get_string(&e->request, &blen);
+ key = key_from_blob(blob, blen);
+ xfree(blob);
+ break;
+ }
+ if (key != NULL) {
+ Identity *id = lookup_identity(key, version);
+ if (id != NULL) {
+ /*
+ * We have this key. Free the old key. Since we
+ * don't want to leave empty slots in the middle of
+ * the array, we actually free the key there and move
+ * all the entries between the empty slot and the end
+ * of the array.
+ */
+ Idtab *tab = idtab_lookup(version);
+ if (tab->nentries < 1)
+ fatal("process_remove_identity: "
+ "internal error: tab->nentries %d",
+ tab->nentries);
+ TAILQ_REMOVE(&tab->idlist, id, next);
+ free_identity(id);
+ tab->nentries--;
+ success = 1;
+ }
+ key_free(key);
+ }
+ buffer_put_int(&e->output, 1);
+ buffer_put_char(&e->output,
+ success ? SSH_AGENT_SUCCESS : SSH_AGENT_FAILURE);
+}
+
+static void
+process_remove_all_identities(SocketEntry *e, int version)
+{
+ Idtab *tab = idtab_lookup(version);
+ Identity *id;
+
+ /* Loop over all identities and clear the keys. */
+ for (id = TAILQ_FIRST(&tab->idlist); id;
+ id = TAILQ_FIRST(&tab->idlist)) {
+ TAILQ_REMOVE(&tab->idlist, id, next);
+ free_identity(id);
+ }
+
+ /* Mark that there are no identities. */
+ tab->nentries = 0;
/* Send success. */
buffer_put_int(&e->output, 1);
buffer_put_char(&e->output, SSH_AGENT_SUCCESS);
- return;
- }
-
- /* Increment the number of identities. */
- num_identities++;
-
- /* Send a success message. */
- buffer_put_int(&e->output, 1);
- buffer_put_char(&e->output, SSH_AGENT_SUCCESS);
}
-void
-process_message(SocketEntry *e)
+/* removes expired keys and returns number of seconds until the next expiry */
+static u_int
+reaper(void)
{
- unsigned int msg_len;
- unsigned int type;
- unsigned char *cp;
- if (buffer_len(&e->input) < 5)
- return; /* Incomplete message. */
- cp = (unsigned char *)buffer_ptr(&e->input);
- msg_len = GET_32BIT(cp);
- if (msg_len > 256 * 1024)
- {
- shutdown(e->fd, SHUT_RDWR);
- close(e->fd);
- e->type = AUTH_UNUSED;
- return;
- }
- if (buffer_len(&e->input) < msg_len + 4)
- return;
- buffer_consume(&e->input, 4);
- type = buffer_get_char(&e->input);
-
- switch (type)
- {
- case SSH_AGENTC_REQUEST_RSA_IDENTITIES:
- process_request_identity(e);
- break;
- case SSH_AGENTC_RSA_CHALLENGE:
- process_authentication_challenge(e);
- break;
- case SSH_AGENTC_ADD_RSA_IDENTITY:
- process_add_identity(e);
- break;
- case SSH_AGENTC_REMOVE_RSA_IDENTITY:
- process_remove_identity(e);
- break;
- case SSH_AGENTC_REMOVE_ALL_RSA_IDENTITIES:
- process_remove_all_identities(e);
- break;
- default:
- /* Unknown message. Respond with failure. */
- error("Unknown message %d", type);
- buffer_clear(&e->input);
- buffer_put_int(&e->output, 1);
- buffer_put_char(&e->output, SSH_AGENT_FAILURE);
- break;
- }
+ u_int deadline = 0, now = time(NULL);
+ Identity *id, *nxt;
+ int version;
+ Idtab *tab;
+
+ for (version = 1; version < 3; version++) {
+ tab = idtab_lookup(version);
+ for (id = TAILQ_FIRST(&tab->idlist); id; id = nxt) {
+ nxt = TAILQ_NEXT(id, next);
+ if (id->death == 0)
+ continue;
+ if (now >= id->death) {
+ debug("expiring key '%s'", id->comment);
+ TAILQ_REMOVE(&tab->idlist, id, next);
+ free_identity(id);
+ tab->nentries--;
+ } else
+ deadline = (deadline == 0) ? id->death :
+ MIN(deadline, id->death);
+ }
+ }
+ if (deadline == 0 || deadline <= now)
+ return 0;
+ else
+ return (deadline - now);
}
-void
-new_socket(int type, int fd)
+static void
+process_add_identity(SocketEntry *e, int version)
+{
+ Idtab *tab = idtab_lookup(version);
+ Identity *id;
+ int type, success = 0, death = 0, confirm = 0;
+ char *type_name, *comment;
+ Key *k = NULL;
+
+ switch (version) {
+ case 1:
+ k = key_new_private(KEY_RSA1);
+ (void) buffer_get_int(&e->request); /* ignored */
+ buffer_get_bignum(&e->request, k->rsa->n);
+ buffer_get_bignum(&e->request, k->rsa->e);
+ buffer_get_bignum(&e->request, k->rsa->d);
+ buffer_get_bignum(&e->request, k->rsa->iqmp);
+
+ /* SSH and SSL have p and q swapped */
+ buffer_get_bignum(&e->request, k->rsa->q); /* p */
+ buffer_get_bignum(&e->request, k->rsa->p); /* q */
+
+ /* Generate additional parameters */
+ rsa_generate_additional_parameters(k->rsa);
+ break;
+ case 2:
+ type_name = buffer_get_string(&e->request, NULL);
+ type = key_type_from_name(type_name);
+ xfree(type_name);
+ switch (type) {
+ case KEY_DSA:
+ k = key_new_private(type);
+ buffer_get_bignum2(&e->request, k->dsa->p);
+ buffer_get_bignum2(&e->request, k->dsa->q);
+ buffer_get_bignum2(&e->request, k->dsa->g);
+ buffer_get_bignum2(&e->request, k->dsa->pub_key);
+ buffer_get_bignum2(&e->request, k->dsa->priv_key);
+ break;
+ case KEY_RSA:
+ k = key_new_private(type);
+ buffer_get_bignum2(&e->request, k->rsa->n);
+ buffer_get_bignum2(&e->request, k->rsa->e);
+ buffer_get_bignum2(&e->request, k->rsa->d);
+ buffer_get_bignum2(&e->request, k->rsa->iqmp);
+ buffer_get_bignum2(&e->request, k->rsa->p);
+ buffer_get_bignum2(&e->request, k->rsa->q);
+
+ /* Generate additional parameters */
+ rsa_generate_additional_parameters(k->rsa);
+ break;
+ default:
+ buffer_clear(&e->request);
+ goto send;
+ }
+ 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);
+ goto send;
+ }
+ while (buffer_len(&e->request)) {
+ switch ((type = 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:
+ error("process_add_identity: "
+ "Unknown constraint type %d", type);
+ xfree(comment);
+ key_free(k);
+ goto send;
+ }
+ }
+ success = 1;
+ if (lifetime && !death)
+ death = time(NULL) + lifetime;
+ if ((id = lookup_identity(k, version)) == NULL) {
+ id = xmalloc(sizeof(Identity));
+ id->key = k;
+ TAILQ_INSERT_TAIL(&tab->idlist, id, next);
+ /* Increment the number of identities. */
+ tab->nentries++;
+ } else {
+ key_free(k);
+ xfree(id->comment);
+ }
+ id->comment = comment;
+ id->death = death;
+ id->confirm = confirm;
+send:
+ buffer_put_int(&e->output, 1);
+ buffer_put_char(&e->output,
+ success ? SSH_AGENT_SUCCESS : SSH_AGENT_FAILURE);
+}
+
+/* XXX todo: encrypt sensitive data with passphrase */
+static void
+process_lock_agent(SocketEntry *e, int lock)
{
- unsigned int i, old_alloc;
- if (fcntl(fd, F_SETFL, O_NONBLOCK) < 0)
- error("fcntl O_NONBLOCK: %s", strerror(errno));
-
- if (fd > max_fd)
- max_fd = fd;
-
- for (i = 0; i < sockets_alloc; i++)
- if (sockets[i].type == AUTH_UNUSED)
- {
- sockets[i].fd = fd;
- sockets[i].type = type;
- buffer_init(&sockets[i].input);
- buffer_init(&sockets[i].output);
- return;
- }
- old_alloc = sockets_alloc;
- sockets_alloc += 10;
- if (sockets)
- sockets = xrealloc(sockets, sockets_alloc * sizeof(sockets[0]));
- else
- sockets = xmalloc(sockets_alloc * sizeof(sockets[0]));
- for (i = old_alloc; i < sockets_alloc; i++)
- sockets[i].type = AUTH_UNUSED;
- sockets[old_alloc].type = type;
- sockets[old_alloc].fd = fd;
- buffer_init(&sockets[old_alloc].input);
- buffer_init(&sockets[old_alloc].output);
+ int success = 0;
+ char *passwd;
+
+ passwd = buffer_get_string(&e->request, NULL);
+ if (locked && !lock && strcmp(passwd, lock_passwd) == 0) {
+ locked = 0;
+ memset(lock_passwd, 0, strlen(lock_passwd));
+ xfree(lock_passwd);
+ lock_passwd = NULL;
+ success = 1;
+ } else if (!locked && lock) {
+ locked = 1;
+ lock_passwd = xstrdup(passwd);
+ success = 1;
+ }
+ memset(passwd, 0, strlen(passwd));
+ xfree(passwd);
+
+ buffer_put_int(&e->output, 1);
+ buffer_put_char(&e->output,
+ success ? SSH_AGENT_SUCCESS : SSH_AGENT_FAILURE);
}
-void
-prepare_select(fd_set *readset, fd_set *writeset)
+static void
+no_identities(SocketEntry *e, u_int type)
{
- unsigned int i;
- for (i = 0; i < sockets_alloc; i++)
- switch (sockets[i].type)
- {
- case AUTH_SOCKET:
- case AUTH_CONNECTION:
- FD_SET(sockets[i].fd, readset);
- if (buffer_len(&sockets[i].output) > 0)
- FD_SET(sockets[i].fd, writeset);
- break;
- case AUTH_UNUSED:
- break;
- default:
- fatal("Unknown socket type %d", sockets[i].type);
- break;
- }
+ Buffer msg;
+
+ buffer_init(&msg);
+ buffer_put_char(&msg,
+ (type == SSH_AGENTC_REQUEST_RSA_IDENTITIES) ?
+ SSH_AGENT_RSA_IDENTITIES_ANSWER : SSH2_AGENT_IDENTITIES_ANSWER);
+ buffer_put_int(&msg, 0);
+ buffer_put_int(&e->output, buffer_len(&msg));
+ buffer_append(&e->output, buffer_ptr(&msg), buffer_len(&msg));
+ buffer_free(&msg);
}
-void after_select(fd_set *readset, fd_set *writeset)
+#ifdef SMARTCARD
+static void
+process_add_smartcard_key(SocketEntry *e)
{
- unsigned int i;
- int len, sock;
- char buf[1024];
- struct sockaddr_un sunaddr;
-
- for (i = 0; i < sockets_alloc; i++)
- switch (sockets[i].type)
- {
- case AUTH_UNUSED:
- break;
- case AUTH_SOCKET:
- if (FD_ISSET(sockets[i].fd, readset))
- {
- len = sizeof(sunaddr);
- sock = accept(sockets[i].fd, (struct sockaddr *)&sunaddr, &len);
- if (sock < 0)
- {
- perror("accept from AUTH_SOCKET");
+ char *sc_reader_id = NULL, *pin;
+ int i, type, 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 ((type = 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:
+ error("process_add_smartcard_key: "
+ "Unknown constraint type %d", type);
+ xfree(sc_reader_id);
+ xfree(pin);
+ goto send;
+ }
+ }
+ if (lifetime && !death)
+ death = time(NULL) + lifetime;
+
+ keys = sc_get_keys(sc_reader_id, pin);
+ xfree(sc_reader_id);
+ xfree(pin);
+
+ if (keys == NULL || keys[0] == NULL) {
+ error("sc_get_keys failed");
+ goto send;
+ }
+ for (i = 0; keys[i] != NULL; i++) {
+ k = keys[i];
+ version = k->type == KEY_RSA1 ? 1 : 2;
+ tab = idtab_lookup(version);
+ if (lookup_identity(k, version) == NULL) {
+ id = xmalloc(sizeof(Identity));
+ id->key = k;
+ id->comment = sc_get_key_label(k);
+ id->death = death;
+ id->confirm = confirm;
+ TAILQ_INSERT_TAIL(&tab->idlist, id, next);
+ tab->nentries++;
+ success = 1;
+ } else {
+ key_free(k);
+ }
+ keys[i] = NULL;
+ }
+ xfree(keys);
+send:
+ buffer_put_int(&e->output, 1);
+ buffer_put_char(&e->output,
+ success ? SSH_AGENT_SUCCESS : SSH_AGENT_FAILURE);
+}
+
+static void
+process_remove_smartcard_key(SocketEntry *e)
+{
+ char *sc_reader_id = NULL, *pin;
+ int i, version, success = 0;
+ Key **keys, *k = NULL;
+ Identity *id;
+ Idtab *tab;
+
+ sc_reader_id = buffer_get_string(&e->request, NULL);
+ pin = buffer_get_string(&e->request, NULL);
+ keys = sc_get_keys(sc_reader_id, pin);
+ xfree(sc_reader_id);
+ xfree(pin);
+
+ if (keys == NULL || keys[0] == NULL) {
+ error("sc_get_keys failed");
+ goto send;
+ }
+ for (i = 0; keys[i] != NULL; i++) {
+ k = keys[i];
+ version = k->type == KEY_RSA1 ? 1 : 2;
+ if ((id = lookup_identity(k, version)) != NULL) {
+ tab = idtab_lookup(version);
+ TAILQ_REMOVE(&tab->idlist, id, next);
+ tab->nentries--;
+ free_identity(id);
+ success = 1;
+ }
+ key_free(k);
+ keys[i] = NULL;
+ }
+ xfree(keys);
+send:
+ buffer_put_int(&e->output, 1);
+ buffer_put_char(&e->output,
+ success ? SSH_AGENT_SUCCESS : SSH_AGENT_FAILURE);
+}
+#endif /* SMARTCARD */
+
+/* dispatch incoming messages */
+
+static void
+process_message(SocketEntry *e)
+{
+ u_int msg_len, type;
+ u_char *cp;
+
+ if (buffer_len(&e->input) < 5)
+ return; /* Incomplete message. */
+ cp = buffer_ptr(&e->input);
+ msg_len = get_u32(cp);
+ if (msg_len > 256 * 1024) {
+ close_socket(e);
+ return;
+ }
+ if (buffer_len(&e->input) < msg_len + 4)
+ return;
+
+ /* move the current input to e->request */
+ buffer_consume(&e->input, 4);
+ buffer_clear(&e->request);
+ buffer_append(&e->request, buffer_ptr(&e->input), msg_len);
+ buffer_consume(&e->input, msg_len);
+ type = buffer_get_char(&e->request);
+
+ /* check wheter agent is locked */
+ if (locked && type != SSH_AGENTC_UNLOCK) {
+ buffer_clear(&e->request);
+ switch (type) {
+ case SSH_AGENTC_REQUEST_RSA_IDENTITIES:
+ case SSH2_AGENTC_REQUEST_IDENTITIES:
+ /* send empty lists */
+ no_identities(e, type);
+ break;
+ default:
+ /* send a fail message for all other request types */
+ buffer_put_int(&e->output, 1);
+ buffer_put_char(&e->output, SSH_AGENT_FAILURE);
+ }
+ return;
+ }
+
+ debug("type %d", type);
+ switch (type) {
+ case SSH_AGENTC_LOCK:
+ case SSH_AGENTC_UNLOCK:
+ process_lock_agent(e, type == SSH_AGENTC_LOCK);
break;
- }
- new_socket(AUTH_CONNECTION, sock);
- }
- break;
- case AUTH_CONNECTION:
- if (buffer_len(&sockets[i].output) > 0 &&
- FD_ISSET(sockets[i].fd, writeset))
- {
- len = write(sockets[i].fd, buffer_ptr(&sockets[i].output),
- buffer_len(&sockets[i].output));
- if (len <= 0)
- {
- shutdown(sockets[i].fd, SHUT_RDWR);
- close(sockets[i].fd);
- sockets[i].type = AUTH_UNUSED;
+ /* ssh1 */
+ case SSH_AGENTC_RSA_CHALLENGE:
+ process_authentication_challenge1(e);
break;
- }
- buffer_consume(&sockets[i].output, len);
- }
- if (FD_ISSET(sockets[i].fd, readset))
- {
- len = read(sockets[i].fd, buf, sizeof(buf));
- if (len <= 0)
- {
- shutdown(sockets[i].fd, SHUT_RDWR);
- close(sockets[i].fd);
- sockets[i].type = AUTH_UNUSED;
+ case SSH_AGENTC_REQUEST_RSA_IDENTITIES:
+ process_request_identities(e, 1);
+ break;
+ case SSH_AGENTC_ADD_RSA_IDENTITY:
+ case SSH_AGENTC_ADD_RSA_ID_CONSTRAINED:
+ process_add_identity(e, 1);
+ break;
+ case SSH_AGENTC_REMOVE_RSA_IDENTITY:
+ process_remove_identity(e, 1);
+ break;
+ case SSH_AGENTC_REMOVE_ALL_RSA_IDENTITIES:
+ process_remove_all_identities(e, 1);
+ break;
+ /* ssh2 */
+ case SSH2_AGENTC_SIGN_REQUEST:
+ process_sign_request2(e);
+ break;
+ case SSH2_AGENTC_REQUEST_IDENTITIES:
+ process_request_identities(e, 2);
+ break;
+ case SSH2_AGENTC_ADD_IDENTITY:
+ case SSH2_AGENTC_ADD_ID_CONSTRAINED:
+ process_add_identity(e, 2);
+ break;
+ case SSH2_AGENTC_REMOVE_IDENTITY:
+ process_remove_identity(e, 2);
+ break;
+ case SSH2_AGENTC_REMOVE_ALL_IDENTITIES:
+ process_remove_all_identities(e, 2);
+ 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:
+ process_remove_smartcard_key(e);
break;
- }
- buffer_append(&sockets[i].input, buf, len);
- process_message(&sockets[i]);
- }
- break;
- default:
- fatal("Unknown type %d", sockets[i].type);
- }
+#endif /* SMARTCARD */
+ default:
+ /* Unknown message. Respond with failure. */
+ error("Unknown message %d", type);
+ buffer_clear(&e->request);
+ buffer_put_int(&e->output, 1);
+ buffer_put_char(&e->output, SSH_AGENT_FAILURE);
+ break;
+ }
}
-void
-check_parent_exists(int sig)
+static void
+new_socket(sock_type type, int fd)
{
- if (kill(parent_pid, 0) < 0)
- {
- /* printf("Parent has died - Authentication agent exiting.\n"); */
- exit(1);
- }
- signal(SIGALRM, check_parent_exists);
- alarm(10);
+ u_int i, old_alloc, new_alloc;
+
+ set_nonblock(fd);
+
+ if (fd > max_fd)
+ max_fd = fd;
+
+ for (i = 0; i < sockets_alloc; i++)
+ if (sockets[i].type == AUTH_UNUSED) {
+ sockets[i].fd = fd;
+ buffer_init(&sockets[i].input);
+ buffer_init(&sockets[i].output);
+ buffer_init(&sockets[i].request);
+ sockets[i].type = type;
+ return;
+ }
+ old_alloc = sockets_alloc;
+ new_alloc = sockets_alloc + 10;
+ sockets = xrealloc(sockets, new_alloc, sizeof(sockets[0]));
+ for (i = old_alloc; i < new_alloc; i++)
+ sockets[i].type = AUTH_UNUSED;
+ sockets_alloc = new_alloc;
+ sockets[old_alloc].fd = fd;
+ buffer_init(&sockets[old_alloc].input);
+ buffer_init(&sockets[old_alloc].output);
+ buffer_init(&sockets[old_alloc].request);
+ sockets[old_alloc].type = type;
}
-void
+static int
+prepare_select(fd_set **fdrp, fd_set **fdwp, int *fdl, u_int *nallocp,
+ struct timeval **tvpp)
+{
+ u_int i, sz, deadline;
+ int n = 0;
+ static struct timeval tv;
+
+ for (i = 0; i < sockets_alloc; i++) {
+ switch (sockets[i].type) {
+ case AUTH_SOCKET:
+ case AUTH_CONNECTION:
+ n = MAX(n, sockets[i].fd);
+ break;
+ case AUTH_UNUSED:
+ break;
+ default:
+ fatal("Unknown socket type %d", sockets[i].type);
+ break;
+ }
+ }
+
+ sz = howmany(n+1, NFDBITS) * sizeof(fd_mask);
+ if (*fdrp == NULL || sz > *nallocp) {
+ if (*fdrp)
+ xfree(*fdrp);
+ if (*fdwp)
+ xfree(*fdwp);
+ *fdrp = xmalloc(sz);
+ *fdwp = xmalloc(sz);
+ *nallocp = sz;
+ }
+ if (n < *fdl)
+ debug("XXX shrink: %d < %d", n, *fdl);
+ *fdl = n;
+ memset(*fdrp, 0, sz);
+ memset(*fdwp, 0, sz);
+
+ for (i = 0; i < sockets_alloc; i++) {
+ switch (sockets[i].type) {
+ case AUTH_SOCKET:
+ case AUTH_CONNECTION:
+ FD_SET(sockets[i].fd, *fdrp);
+ if (buffer_len(&sockets[i].output) > 0)
+ FD_SET(sockets[i].fd, *fdwp);
+ break;
+ default:
+ break;
+ }
+ }
+ deadline = reaper();
+ if (parent_alive_interval != 0)
+ deadline = (deadline == 0) ? parent_alive_interval :
+ MIN(deadline, parent_alive_interval);
+ if (deadline == 0) {
+ *tvpp = NULL;
+ } else {
+ tv.tv_sec = deadline;
+ tv.tv_usec = 0;
+ *tvpp = &tv;
+ }
+ return (1);
+}
+
+static void
+after_select(fd_set *readset, fd_set *writeset)
+{
+ struct sockaddr_un sunaddr;
+ socklen_t slen;
+ char buf[1024];
+ int len, sock;
+ u_int i, orig_alloc;
+ uid_t euid;
+ gid_t egid;
+
+ for (i = 0, orig_alloc = sockets_alloc; i < orig_alloc; i++)
+ switch (sockets[i].type) {
+ case AUTH_UNUSED:
+ break;
+ case AUTH_SOCKET:
+ if (FD_ISSET(sockets[i].fd, readset)) {
+ slen = sizeof(sunaddr);
+ sock = accept(sockets[i].fd,
+ (struct sockaddr *)&sunaddr, &slen);
+ if (sock < 0) {
+ error("accept from AUTH_SOCKET: %s",
+ strerror(errno));
+ break;
+ }
+ if (getpeereid(sock, &euid, &egid) < 0) {
+ error("getpeereid %d failed: %s",
+ sock, strerror(errno));
+ close(sock);
+ break;
+ }
+ if ((euid != 0) && (getuid() != euid)) {
+ error("uid mismatch: "
+ "peer euid %u != uid %u",
+ (u_int) euid, (u_int) getuid());
+ close(sock);
+ break;
+ }
+ new_socket(AUTH_CONNECTION, sock);
+ }
+ break;
+ case AUTH_CONNECTION:
+ if (buffer_len(&sockets[i].output) > 0 &&
+ FD_ISSET(sockets[i].fd, writeset)) {
+ len = write(sockets[i].fd,
+ buffer_ptr(&sockets[i].output),
+ buffer_len(&sockets[i].output));
+ if (len == -1 && (errno == EAGAIN ||
+ errno == EWOULDBLOCK ||
+ errno == EINTR))
+ continue;
+ if (len <= 0) {
+ close_socket(&sockets[i]);
+ break;
+ }
+ buffer_consume(&sockets[i].output, len);
+ }
+ if (FD_ISSET(sockets[i].fd, readset)) {
+ len = read(sockets[i].fd, buf, sizeof(buf));
+ if (len == -1 && (errno == EAGAIN ||
+ errno == EWOULDBLOCK ||
+ errno == EINTR))
+ continue;
+ if (len <= 0) {
+ close_socket(&sockets[i]);
+ break;
+ }
+ buffer_append(&sockets[i].input, buf, len);
+ process_message(&sockets[i]);
+ }
+ break;
+ default:
+ fatal("Unknown type %d", sockets[i].type);
+ }
+}
+
+static void
cleanup_socket(void)
{
- remove(socket_name);
- rmdir(socket_dir);
+ if (socket_name[0])
+ unlink(socket_name);
+ if (socket_dir[0])
+ rmdir(socket_dir);
}
void
cleanup_exit(int i)
{
- cleanup_socket();
- exit(i);
+ cleanup_socket();
+ _exit(i);
}
-void
-usage()
+/*ARGSUSED*/
+static void
+cleanup_handler(int sig)
{
- extern char *__progname;
+ cleanup_socket();
+ _exit(2);
+}
- fprintf(stderr, "ssh-agent version %s\n", SSH_VERSION);
- fprintf(stderr, "Usage: %s [-c | -s] [-k] [command {args...]]\n",
- __progname);
- exit(1);
+static void
+check_parent_exists(void)
+{
+ if (parent_pid != -1 && kill(parent_pid, 0) < 0) {
+ /* printf("Parent has died - Authentication agent exiting.\n"); */
+ cleanup_socket();
+ _exit(2);
+ }
+}
+
+static void
+usage(void)
+{
+ fprintf(stderr, "usage: %s [options] [command [arg ...]]\n",
+ __progname);
+ fprintf(stderr, "Options:\n");
+ fprintf(stderr, " -c Generate C-shell commands on stdout.\n");
+ fprintf(stderr, " -s Generate Bourne shell commands on stdout.\n");
+ 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)
{
- fd_set readset, writeset;
- int sock, c_flag = 0, k_flag = 0, s_flag = 0, ch;
- struct sockaddr_un sunaddr;
- pid_t pid;
- char *shell, *format, *pidstr, pidstrbuf[1 + 3 * sizeof pid];
-
- /* check if RSA support exists */
- if (rsa_alive() == 0) {
- extern char *__progname;
- fprintf(stderr,
- "%s: no RSA support in libssl and libcrypto. See ssl(8).\n",
- __progname);
- exit(1);
- }
-
- while ((ch = getopt(ac, av, "cks")) != -1)
- {
- switch (ch)
- {
- case 'c':
- if (s_flag)
- usage();
- c_flag++;
- break;
- case 'k':
- k_flag++;
- break;
- case 's':
- if (c_flag)
- usage();
- s_flag++;
- break;
- default:
- usage();
- }
- }
- ac -= optind;
- av += optind;
-
- if (ac > 0 && (c_flag || k_flag || s_flag))
- usage();
-
- if (ac == 0 && !c_flag && !k_flag && !s_flag)
- {
- shell = getenv("SHELL");
- if (shell != NULL && strncmp(shell + strlen(shell) - 3, "csh", 3) == 0)
- c_flag = 1;
- }
-
- if (k_flag)
- {
- pidstr = getenv(SSH_AGENTPID_ENV_NAME);
- if (pidstr == NULL)
- {
- fprintf(stderr, "%s not set, cannot kill agent\n",
- SSH_AGENTPID_ENV_NAME);
- exit(1);
- }
- pid = atoi(pidstr);
- if (pid < 1) /* XXX PID_MAX check too */
- {
- fprintf(stderr, "%s=\"%s\", which is not a good PID\n",
- SSH_AGENTPID_ENV_NAME, pidstr);
- exit(1);
- }
- if (kill(pid, SIGTERM) == -1)
- {
- perror("kill");
- exit(1);
- }
- format = c_flag ? "unsetenv %s;\n" : "unset %s;\n";
- printf(format, SSH_AUTHSOCKET_ENV_NAME);
- printf(format, SSH_AGENTPID_ENV_NAME);
- printf("echo Agent pid %d killed;\n", pid);
- exit(0);
- }
-
- parent_pid = getpid();
-
- /* Create private directory for agent socket */
- strlcpy(socket_dir, "/tmp/ssh-XXXXXXXX", sizeof socket_dir);
- if (mkdtemp(socket_dir) == NULL) {
- perror("mkdtemp: private socket dir");
- exit(1);
- }
- snprintf(socket_name, sizeof socket_name, "%s/agent.%d", socket_dir,
- parent_pid);
-
- /* Create socket early so it will exist before command gets run from
- the parent. */
- sock = socket(AF_UNIX, SOCK_STREAM, 0);
- if (sock < 0)
- {
- perror("socket");
- cleanup_exit(1);
- }
- memset(&sunaddr, 0, sizeof(sunaddr));
- sunaddr.sun_family = AF_UNIX;
- strlcpy(sunaddr.sun_path, socket_name, sizeof(sunaddr.sun_path));
- if (bind(sock, (struct sockaddr *)&sunaddr, sizeof(sunaddr)) < 0)
- {
- perror("bind");
- cleanup_exit(1);
- }
- if (listen(sock, 5) < 0)
- {
- perror("listen");
- cleanup_exit(1);
- }
-
- /* Fork, and have the parent execute the command, if any, or present the
- socket data. The child continues as the authentication agent. */
- pid = fork();
- if (pid == -1)
- {
- perror("fork");
- exit(1);
- }
- if (pid != 0)
- { /* Parent - execute the given command. */
- close(sock);
- snprintf(pidstrbuf, sizeof pidstrbuf, "%d", pid);
- if (ac == 0)
- {
- format = c_flag ? "setenv %s %s;\n" : "%s=%s; export %s;\n";
- printf(format, SSH_AUTHSOCKET_ENV_NAME, socket_name,
- SSH_AUTHSOCKET_ENV_NAME);
- printf(format, SSH_AGENTPID_ENV_NAME, pidstrbuf,
- SSH_AGENTPID_ENV_NAME);
- printf("echo Agent pid %d;\n", pid);
- exit(0);
- }
-
- setenv(SSH_AUTHSOCKET_ENV_NAME, socket_name, 1);
- setenv(SSH_AGENTPID_ENV_NAME, pidstrbuf, 1);
- execvp(av[0], av);
- perror(av[0]);
- exit(1);
- }
-
- close(0);
- close(1);
- close(2);
-
- if (ac == 0 && setsid() == -1)
- cleanup_exit(1);
-
- if (atexit(cleanup_socket) < 0)
- cleanup_exit(1);
-
- new_socket(AUTH_SOCKET, sock);
- if (ac > 0)
- {
- signal(SIGALRM, check_parent_exists);
- alarm(10);
- }
-
- signal(SIGINT, SIG_IGN);
- signal(SIGPIPE, SIG_IGN);
- while (1)
- {
- FD_ZERO(&readset);
- FD_ZERO(&writeset);
- prepare_select(&readset, &writeset);
- if (select(max_fd + 1, &readset, &writeset, NULL, NULL) < 0)
- {
- if (errno == EINTR)
- continue;
- exit(1);
- }
- after_select(&readset, &writeset);
- }
- /*NOTREACHED*/
+ int c_flag = 0, d_flag = 0, k_flag = 0, s_flag = 0;
+ int sock, fd, ch, result, saved_errno;
+ u_int nalloc;
+ char *shell, *format, *pidstr, *agentsocket = NULL;
+ fd_set *readsetp = NULL, *writesetp = NULL;
+ struct sockaddr_un sunaddr;
+#ifdef HAVE_SETRLIMIT
+ struct rlimit rlim;
+#endif
+ int prev_mask;
+ extern int optind;
+ extern char *optarg;
+ pid_t pid;
+ char pidstrbuf[1 + 3 * sizeof pid];
+ struct timeval *tvp = NULL;
+ size_t len;
+
+ /* Ensure that fds 0, 1 and 2 are open or directed to /dev/null */
+ sanitise_stdfd();
+
+ /* drop */
+ setegid(getgid());
+ setgid(getgid());
+
+#if defined(HAVE_PRCTL) && defined(PR_SET_DUMPABLE)
+ /* Disable ptrace on Linux without sgid bit */
+ prctl(PR_SET_DUMPABLE, 0);
+#endif
+
+ SSLeay_add_all_algorithms();
+
+ __progname = ssh_get_progname(av[0]);
+ init_rng();
+ seed_rng();
+
+ while ((ch = getopt(ac, av, "cdksa:t:")) != -1) {
+ switch (ch) {
+ case 'c':
+ if (s_flag)
+ usage();
+ c_flag++;
+ break;
+ case 'k':
+ k_flag++;
+ break;
+ case 's':
+ if (c_flag)
+ usage();
+ s_flag++;
+ break;
+ case 'd':
+ if (d_flag)
+ usage();
+ d_flag++;
+ break;
+ case 'a':
+ agentsocket = optarg;
+ break;
+ case 't':
+ if ((lifetime = convtime(optarg)) == -1) {
+ fprintf(stderr, "Invalid lifetime\n");
+ usage();
+ }
+ break;
+ default:
+ usage();
+ }
+ }
+ ac -= optind;
+ av += optind;
+
+ if (ac > 0 && (c_flag || k_flag || s_flag || d_flag))
+ usage();
+
+ if (ac == 0 && !c_flag && !s_flag) {
+ shell = getenv("SHELL");
+ if (shell != NULL && (len = strlen(shell)) > 2 &&
+ strncmp(shell + len - 3, "csh", 3) == 0)
+ c_flag = 1;
+ }
+ if (k_flag) {
+ const char *errstr = NULL;
+
+ pidstr = getenv(SSH_AGENTPID_ENV_NAME);
+ if (pidstr == NULL) {
+ fprintf(stderr, "%s not set, cannot kill agent\n",
+ SSH_AGENTPID_ENV_NAME);
+ exit(1);
+ }
+ pid = (int)strtonum(pidstr, 2, INT_MAX, &errstr);
+ if (errstr) {
+ fprintf(stderr,
+ "%s=\"%s\", which is not a good PID: %s\n",
+ SSH_AGENTPID_ENV_NAME, pidstr, errstr);
+ exit(1);
+ }
+ if (kill(pid, SIGTERM) == -1) {
+ perror("kill");
+ exit(1);
+ }
+ format = c_flag ? "unsetenv %s;\n" : "unset %s;\n";
+ printf(format, SSH_AUTHSOCKET_ENV_NAME);
+ printf(format, SSH_AGENTPID_ENV_NAME);
+ printf("echo Agent pid %ld killed;\n", (long)pid);
+ exit(0);
+ }
+ parent_pid = getpid();
+
+ if (agentsocket == NULL) {
+ /* Create private directory for agent socket */
+ strlcpy(socket_dir, "/tmp/ssh-XXXXXXXXXX", sizeof socket_dir);
+ if (mkdtemp(socket_dir) == NULL) {
+ perror("mkdtemp: private socket dir");
+ exit(1);
+ }
+ snprintf(socket_name, sizeof socket_name, "%s/agent.%ld", socket_dir,
+ (long)parent_pid);
+ } else {
+ /* Try to use specified agent socket */
+ socket_dir[0] = '\0';
+ strlcpy(socket_name, agentsocket, sizeof socket_name);
+ }
+
+ /*
+ * Create socket early so it will exist before command gets run from
+ * the parent.
+ */
+ sock = socket(AF_UNIX, SOCK_STREAM, 0);
+ if (sock < 0) {
+ perror("socket");
+ *socket_name = '\0'; /* Don't unlink any existing file */
+ cleanup_exit(1);
+ }
+ memset(&sunaddr, 0, sizeof(sunaddr));
+ sunaddr.sun_family = AF_UNIX;
+ strlcpy(sunaddr.sun_path, socket_name, sizeof(sunaddr.sun_path));
+ prev_mask = umask(0177);
+ if (bind(sock, (struct sockaddr *) &sunaddr, sizeof(sunaddr)) < 0) {
+ perror("bind");
+ *socket_name = '\0'; /* Don't unlink any existing file */
+ umask(prev_mask);
+ cleanup_exit(1);
+ }
+ umask(prev_mask);
+ if (listen(sock, SSH_LISTEN_BACKLOG) < 0) {
+ perror("listen");
+ cleanup_exit(1);
+ }
+
+ /*
+ * Fork, and have the parent execute the command, if any, or present
+ * the socket data. The child continues as the authentication agent.
+ */
+ if (d_flag) {
+ log_init(__progname, SYSLOG_LEVEL_DEBUG1, SYSLOG_FACILITY_AUTH, 1);
+ format = c_flag ? "setenv %s %s;\n" : "%s=%s; export %s;\n";
+ printf(format, SSH_AUTHSOCKET_ENV_NAME, socket_name,
+ SSH_AUTHSOCKET_ENV_NAME);
+ printf("echo Agent pid %ld;\n", (long)parent_pid);
+ goto skip;
+ }
+ pid = fork();
+ if (pid == -1) {
+ perror("fork");
+ cleanup_exit(1);
+ }
+ if (pid != 0) { /* Parent - execute the given command. */
+ close(sock);
+ snprintf(pidstrbuf, sizeof pidstrbuf, "%ld", (long)pid);
+ if (ac == 0) {
+ format = c_flag ? "setenv %s %s;\n" : "%s=%s; export %s;\n";
+ printf(format, SSH_AUTHSOCKET_ENV_NAME, socket_name,
+ SSH_AUTHSOCKET_ENV_NAME);
+ printf(format, SSH_AGENTPID_ENV_NAME, pidstrbuf,
+ SSH_AGENTPID_ENV_NAME);
+ printf("echo Agent pid %ld;\n", (long)pid);
+ exit(0);
+ }
+ if (setenv(SSH_AUTHSOCKET_ENV_NAME, socket_name, 1) == -1 ||
+ setenv(SSH_AGENTPID_ENV_NAME, pidstrbuf, 1) == -1) {
+ perror("setenv");
+ exit(1);
+ }
+ execvp(av[0], av);
+ perror(av[0]);
+ exit(1);
+ }
+ /* child */
+ log_init(__progname, SYSLOG_LEVEL_INFO, SYSLOG_FACILITY_AUTH, 0);
+
+ if (setsid() == -1) {
+ error("setsid: %s", strerror(errno));
+ cleanup_exit(1);
+ }
+
+ (void)chdir("/");
+ 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 */
+ rlim.rlim_cur = rlim.rlim_max = 0;
+ if (setrlimit(RLIMIT_CORE, &rlim) < 0) {
+ error("setrlimit RLIMIT_CORE: %s", strerror(errno));
+ cleanup_exit(1);
+ }
+#endif
+
+skip:
+ new_socket(AUTH_SOCKET, sock);
+ if (ac > 0)
+ parent_alive_interval = 10;
+ idtab_init();
+ if (!d_flag)
+ signal(SIGINT, SIG_IGN);
+ signal(SIGPIPE, SIG_IGN);
+ signal(SIGHUP, cleanup_handler);
+ signal(SIGTERM, cleanup_handler);
+ nalloc = 0;
+
+ while (1) {
+ prepare_select(&readsetp, &writesetp, &max_fd, &nalloc, &tvp);
+ result = select(max_fd + 1, readsetp, writesetp, NULL, tvp);
+ saved_errno = errno;
+ if (parent_alive_interval != 0)
+ check_parent_exists();
+ (void) reaper(); /* remove expired keys */
+ if (result < 0) {
+ if (saved_errno == EINTR)
+ continue;
+ fatal("select: %s", strerror(saved_errno));
+ } else if (result > 0)
+ after_select(readsetp, writesetp);
+ }
+ /* NOTREACHED */
}
andersk / openssh.git / blobdiff