| /* |
| * 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. |
| */ |
| |
| #include "includes.h" |
| #include "openbsd-compat/fake-queue.h" |
| RCSID("$OpenBSD: ssh-agent.c,v 1.103 2002/09/10 20:24:47 markus Exp $"); |
| |
| #include <openssl/evp.h> |
| #include <openssl/md5.h> |
| |
| #include "ssh.h" |
| #include "rsa.h" |
| #include "buffer.h" |
| #include "bufaux.h" |
| #include "xmalloc.h" |
| #include "getput.h" |
| #include "key.h" |
| #include "authfd.h" |
| #include "compat.h" |
| #include "log.h" |
| |
| #ifdef SMARTCARD |
| #include "scard.h" |
| #endif |
| |
| typedef enum { |
| AUTH_UNUSED, |
| AUTH_SOCKET, |
| AUTH_CONNECTION |
| } sock_type; |
| |
| typedef struct { |
| int fd; |
| sock_type type; |
| Buffer input; |
| Buffer output; |
| Buffer request; |
| } SocketEntry; |
| |
| u_int sockets_alloc = 0; |
| SocketEntry *sockets = NULL; |
| |
| typedef struct identity { |
| TAILQ_ENTRY(identity) next; |
| Key *key; |
| char *comment; |
| u_int death; |
| } Identity; |
| |
| 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 */ |
| pid_t parent_pid = -1; |
| |
| /* pathname and directory for AUTH_SOCKET */ |
| char socket_name[1024]; |
| char socket_dir[1024]; |
| |
| /* locking */ |
| int locked = 0; |
| char *lock_passwd = NULL; |
| |
| #ifdef HAVE___PROGNAME |
| extern char *__progname; |
| #else |
| char *__progname; |
| #endif |
| |
| static void |
| close_socket(SocketEntry *e) |
| { |
| close(e->fd); |
| e->fd = -1; |
| e->type = AUTH_UNUSED; |
| buffer_free(&e->input); |
| buffer_free(&e->output); |
| buffer_free(&e->request); |
| } |
| |
| static void |
| idtab_init(void) |
| { |
| int i; |
| |
| for (i = 0; i <=2; i++) { |
| TAILQ_INIT(&idtable[i].idlist); |
| idtable[i].nentries = 0; |
| } |
| } |
| |
| /* return private key table for requested protocol version */ |
| static Idtab * |
| idtab_lookup(int version) |
| { |
| if (version < 1 || version > 2) |
| fatal("internal error, bad protocol version %d", version); |
| return &idtable[version]; |
| } |
| |
| static void |
| free_identity(Identity *id) |
| { |
| key_free(id->key); |
| xfree(id->comment); |
| xfree(id); |
| } |
| |
| /* return matching private key for given public key */ |
| static Identity * |
| lookup_identity(Key *key, int version) |
| { |
| Identity *id; |
| |
| Idtab *tab = idtab_lookup(version); |
| TAILQ_FOREACH(id, &tab->idlist, next) { |
| if (key_equal(key, id->key)) |
| return (id); |
| } |
| return (NULL); |
| } |
| |
| /* 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); |
| } |
| |
| /* 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) { |
| 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) { |
| log("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 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); |
| 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) |
| 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); |
| } |
| |
| /* shared */ |
| static void |
| process_remove_identity(SocketEntry *e, int version) |
| { |
| 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)) |
| log("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); |
| } |
| |
| static void |
| reaper(void) |
| { |
| u_int 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 && now >= id->death) { |
| TAILQ_REMOVE(&tab->idlist, id, next); |
| free_identity(id); |
| tab->nentries--; |
| } |
| } |
| } |
| } |
| |
| static void |
| process_add_identity(SocketEntry *e, int version) |
| { |
| Idtab *tab = idtab_lookup(version); |
| int type, success = 0, death = 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; |
| } |
| comment = buffer_get_string(&e->request, NULL); |
| if (k == NULL) { |
| xfree(comment); |
| goto send; |
| } |
| success = 1; |
| 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; |
| default: |
| break; |
| } |
| } |
| if (lookup_identity(k, version) == NULL) { |
| Identity *id = xmalloc(sizeof(Identity)); |
| id->key = k; |
| id->comment = comment; |
| id->death = death; |
| TAILQ_INSERT_TAIL(&tab->idlist, id, next); |
| /* Increment the number of identities. */ |
| tab->nentries++; |
| } else { |
| key_free(k); |
| xfree(comment); |
| } |
| 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) |
| { |
| 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); |
| } |
| |
| static void |
| no_identities(SocketEntry *e, u_int type) |
| { |
| 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); |
| } |
| |
| #ifdef SMARTCARD |
| static void |
| process_add_smartcard_key (SocketEntry *e) |
| { |
| char *sc_reader_id = NULL, *pin; |
| int i, version, success = 0; |
| Key **keys, *k; |
| 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; |
| tab = idtab_lookup(version); |
| if (lookup_identity(k, version) == NULL) { |
| id = xmalloc(sizeof(Identity)); |
| id->key = k; |
| id->comment = xstrdup("smartcard key"); |
| id->death = 0; |
| 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; |
| |
| /* kill dead keys */ |
| reaper(); |
| |
| if (buffer_len(&e->input) < 5) |
| return; /* Incomplete message. */ |
| cp = buffer_ptr(&e->input); |
| msg_len = GET_32BIT(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; |
| /* ssh1 */ |
| case SSH_AGENTC_RSA_CHALLENGE: |
| process_authentication_challenge1(e); |
| break; |
| 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: |
| process_add_smartcard_key(e); |
| break; |
| case SSH_AGENTC_REMOVE_SMARTCARD_KEY: |
| process_remove_smartcard_key(e); |
| break; |
| #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; |
| } |
| } |
| |
| static void |
| new_socket(sock_type type, int fd) |
| { |
| u_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); |
| buffer_init(&sockets[i].request); |
| 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); |
| buffer_init(&sockets[old_alloc].request); |
| } |
| |
| static int |
| prepare_select(fd_set **fdrp, fd_set **fdwp, int *fdl, int *nallocp) |
| { |
| u_int i, sz; |
| int n = 0; |
| |
| 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; |
| } |
| } |
| 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; |
| uid_t euid; |
| gid_t egid; |
| |
| 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)) { |
| 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 (getuid() != euid) { |
| error("uid mismatch: " |
| "peer euid %d != uid %d", |
| (int) euid, (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)) { |
| do { |
| len = write(sockets[i].fd, |
| buffer_ptr(&sockets[i].output), |
| buffer_len(&sockets[i].output)); |
| if (len == -1 && (errno == EAGAIN || |
| errno == EINTR)) |
| continue; |
| break; |
| } while (1); |
| if (len <= 0) { |
| close_socket(&sockets[i]); |
| break; |
| } |
| buffer_consume(&sockets[i].output, len); |
| } |
| if (FD_ISSET(sockets[i].fd, readset)) { |
| do { |
| len = read(sockets[i].fd, buf, sizeof(buf)); |
| if (len == -1 && (errno == EAGAIN || |
| errno == EINTR)) |
| continue; |
| break; |
| } while (1); |
| 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 *p) |
| { |
| if (socket_name[0]) |
| unlink(socket_name); |
| if (socket_dir[0]) |
| rmdir(socket_dir); |
| } |
| |
| static void |
| cleanup_exit(int i) |
| { |
| cleanup_socket(NULL); |
| exit(i); |
| } |
| |
| static void |
| cleanup_handler(int sig) |
| { |
| cleanup_socket(NULL); |
| _exit(2); |
| } |
| |
| static void |
| check_parent_exists(int sig) |
| { |
| int save_errno = errno; |
| |
| if (parent_pid != -1 && kill(parent_pid, 0) < 0) { |
| /* printf("Parent has died - Authentication agent exiting.\n"); */ |
| cleanup_handler(sig); /* safe */ |
| } |
| signal(SIGALRM, check_parent_exists); |
| alarm(10); |
| errno = save_errno; |
| } |
| |
| static void |
| usage(void) |
| { |
| fprintf(stderr, "Usage: %s [options] [command [args ...]]\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"); |
| exit(1); |
| } |
| |
| int |
| main(int ac, char **av) |
| { |
| int sock, c_flag = 0, d_flag = 0, k_flag = 0, s_flag = 0, ch, nalloc; |
| char *shell, *format, *pidstr, *agentsocket = NULL; |
| fd_set *readsetp = NULL, *writesetp = NULL; |
| struct sockaddr_un sunaddr; |
| #ifdef HAVE_SETRLIMIT |
| struct rlimit rlim; |
| #endif |
| #ifdef HAVE_CYGWIN |
| int prev_mask; |
| #endif |
| extern int optind; |
| extern char *optarg; |
| pid_t pid; |
| char pidstrbuf[1 + 3 * sizeof pid]; |
| |
| /* drop */ |
| setegid(getgid()); |
| setgid(getgid()); |
| |
| SSLeay_add_all_algorithms(); |
| |
| __progname = get_progname(av[0]); |
| init_rng(); |
| seed_rng(); |
| |
| while ((ch = getopt(ac, av, "cdksa:")) != -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; |
| 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 && 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) { |
| 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 %ld killed;\n", (long)pid); |
| exit(0); |
| } |
| parent_pid = getpid(); |
| |
| if (agentsocket == NULL) { |
| /* 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.%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"); |
| cleanup_exit(1); |
| } |
| memset(&sunaddr, 0, sizeof(sunaddr)); |
| sunaddr.sun_family = AF_UNIX; |
| strlcpy(sunaddr.sun_path, socket_name, sizeof(sunaddr.sun_path)); |
| #ifdef HAVE_CYGWIN |
| prev_mask = umask(0177); |
| #endif |
| if (bind(sock, (struct sockaddr *) & sunaddr, sizeof(sunaddr)) < 0) { |
| perror("bind"); |
| #ifdef HAVE_CYGWIN |
| umask(prev_mask); |
| #endif |
| cleanup_exit(1); |
| } |
| #ifdef HAVE_CYGWIN |
| umask(prev_mask); |
| #endif |
| if (listen(sock, 128) < 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("/"); |
| close(0); |
| close(1); |
| close(2); |
| |
| #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: |
| fatal_add_cleanup(cleanup_socket, NULL); |
| new_socket(AUTH_SOCKET, sock); |
| if (ac > 0) { |
| signal(SIGALRM, check_parent_exists); |
| alarm(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); |
| if (select(max_fd + 1, readsetp, writesetp, NULL, NULL) < 0) { |
| if (errno == EINTR) |
| continue; |
| fatal("select: %s", strerror(errno)); |
| } |
| after_select(readsetp, writesetp); |
| } |
| /* NOTREACHED */ |
| } |