X-Git-Url: http://andersk.mit.edu/gitweb/openssh.git/blobdiff_plain/762f5ea20dc6932e32901990938229c79a711031..HEAD:/ssh-agent.c diff --git a/ssh-agent.c b/ssh-agent.c index a0bc9cf0..df3a87d9 100644 --- a/ssh-agent.c +++ b/ssh-agent.c @@ -1,5 +1,4 @@ -/* $OpenBSD: ssh-agent.c,v 1.80 2002/02/04 00:53:39 stevesk Exp $ */ - +/* $OpenBSD: ssh-agent.c,v 1.162 2009/09/01 14:43:17 djm Exp $ */ /* * Author: Tatu Ylonen * Copyright (c) 1995 Tatu Ylonen , Espoo, Finland @@ -36,34 +35,55 @@ */ #include "includes.h" -RCSID("$OpenBSD: ssh-agent.c,v 1.80 2002/02/04 00:53:39 stevesk Exp $"); -#if defined(HAVE_SYS_QUEUE_H) && !defined(HAVE_BOGUS_SYS_QUEUE_H) -#include -#else -#include "openbsd-compat/fake-queue.h" +#include +#include +#include +#include +#include +#ifdef HAVE_SYS_TIME_H +# include #endif - +#ifdef HAVE_SYS_UN_H +# include +#endif +#include "openbsd-compat/sys-queue.h" #include #include +#include "openbsd-compat/openssl-compat.h" +#include +#include +#ifdef HAVE_PATHS_H +# include +#endif +#include +#include +#include +#include +#include +#include +#include + +#include "xmalloc.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" +#include "misc.h" #ifdef SMARTCARD -#include #include "scard.h" #endif +#if defined(HAVE_SYS_PRCTL_H) +#include /* For prctl() and PR_SET_DUMPABLE */ +#endif + typedef enum { AUTH_UNUSED, AUTH_SOCKET, @@ -75,6 +95,7 @@ typedef struct { sock_type type; Buffer input; Buffer output; + Buffer request; } SocketEntry; u_int sockets_alloc = 0; @@ -84,6 +105,8 @@ typedef struct identity { TAILQ_ENTRY(identity) next; Key *key; char *comment; + u_int death; + u_int confirm; } Identity; typedef struct { @@ -98,21 +121,37 @@ int max_fd = 0; /* pid of shell == parent of agent */ 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]; + +/* locking */ +int locked = 0; +char *lock_passwd = NULL; -#ifdef HAVE___PROGNAME extern char *__progname; -#else -char *__progname; -#endif + +/* Default lifetime (0 == forever) */ +static int lifetime = 0; + +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; @@ -128,6 +167,14 @@ idtab_lookup(int 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) @@ -142,12 +189,20 @@ lookup_identity(Key *key, int version) return (NULL); } -static void -free_identity(Identity *id) +/* Check confirmation of keysign request */ +static int +confirm_key(Identity *id) { - key_free(id->key); - xfree(id->comment); - xfree(id); + 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); } /* send list of supported public keys to 'client' */ @@ -155,8 +210,8 @@ static void process_request_identities(SocketEntry *e, int version) { Idtab *tab = idtab_lookup(version); - Buffer msg; Identity *id; + Buffer msg; buffer_init(&msg); buffer_put_char(&msg, (version == 1) ? @@ -185,35 +240,35 @@ process_request_identities(SocketEntry *e, int version) static void process_authentication_challenge1(SocketEntry *e) { - Identity *id; - Key *key; + 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; - u_char buf[32], mdbuf[16], session_id[16]; - u_int response_type; + Key *key; buffer_init(&msg); key = key_new(KEY_RSA1); if ((challenge = BN_new()) == NULL) fatal("process_authentication_challenge1: BN_new failed"); - buffer_get_int(&e->input); /* ignored */ - buffer_get_bignum(&e->input, key->rsa->e); - buffer_get_bignum(&e->input, key->rsa->n); - buffer_get_bignum(&e->input, challenge); + (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->input) == 0) + if (buffer_len(&e->request) == 0) goto failure; - buffer_get(&e->input, session_id, 16); - response_type = buffer_get_int(&e->input); + 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) { + 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) @@ -222,7 +277,7 @@ 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); @@ -254,30 +309,31 @@ send: static void process_sign_request2(SocketEntry *e) { - extern int datafellows; - Key *key; u_char *blob, *data, *signature = NULL; u_int blen, dlen, slen = 0; - int flags; + extern int datafellows; + int odatafellows; + int ok = -1, flags; Buffer msg; - int ok = -1; + Key *key; datafellows = 0; - blob = buffer_get_string(&e->input, &blen); - data = buffer_get_string(&e->input, &dlen); + blob = buffer_get_string(&e->request, &blen); + data = buffer_get_string(&e->request, &dlen); - flags = buffer_get_int(&e->input); + 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) + if (id != NULL && (!id->confirm || confirm_key(id) == 0)) ok = key_sign(id->key, &signature, &slen, data, dlen); + key_free(key); } - key_free(key); buffer_init(&msg); if (ok == 0) { buffer_put_char(&msg, SSH2_AGENT_SIGN_RESPONSE); @@ -293,31 +349,31 @@ process_sign_request2(SocketEntry *e) xfree(blob); if (signature != NULL) xfree(signature); + datafellows = odatafellows; } /* shared */ static void process_remove_identity(SocketEntry *e, int version) { + u_int blen, bits; + int success = 0; Key *key = NULL; u_char *blob; - u_int blen; - u_int bits; - int success = 0; switch (version) { case 1: key = key_new(KEY_RSA1); - bits = buffer_get_int(&e->input); - buffer_get_bignum(&e->input, key->rsa->e); - buffer_get_bignum(&e->input, key->rsa->n); + 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 %d, announced %d", + logit("Warning: identity keysize mismatch: actual %u, announced %u", key_size(key), bits); break; case 2: - blob = buffer_get_string(&e->input, &blen); + blob = buffer_get_string(&e->request, &blen); key = key_from_blob(blob, blen); xfree(blob); break; @@ -327,7 +383,7 @@ process_remove_identity(SocketEntry *e, int 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 + * 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. @@ -368,135 +424,250 @@ process_remove_all_identities(SocketEntry *e, int version) /* Send success. */ buffer_put_int(&e->output, 1); buffer_put_char(&e->output, SSH_AGENT_SUCCESS); - return; +} + +/* removes expired keys and returns number of seconds until the next expiry */ +static u_int +reaper(void) +{ + 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); } static void process_add_identity(SocketEntry *e, int version) { - Key *k = NULL; - char *type_name; - char *comment; - int type, success = 0; 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); - buffer_get_int(&e->input); /* ignored */ - buffer_get_bignum(&e->input, k->rsa->n); - buffer_get_bignum(&e->input, k->rsa->e); - buffer_get_bignum(&e->input, k->rsa->d); - buffer_get_bignum(&e->input, k->rsa->iqmp); + (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->input, k->rsa->q); /* p */ - buffer_get_bignum(&e->input, k->rsa->p); /* q */ + 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->input, NULL); + 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->input, k->dsa->p); - buffer_get_bignum2(&e->input, k->dsa->q); - buffer_get_bignum2(&e->input, k->dsa->g); - buffer_get_bignum2(&e->input, k->dsa->pub_key); - buffer_get_bignum2(&e->input, k->dsa->priv_key); + 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->input, k->rsa->n); - buffer_get_bignum2(&e->input, k->rsa->e); - buffer_get_bignum2(&e->input, k->rsa->d); - buffer_get_bignum2(&e->input, k->rsa->iqmp); - buffer_get_bignum2(&e->input, k->rsa->p); - buffer_get_bignum2(&e->input, k->rsa->q); + 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->input); + 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->input, NULL); + 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 (lookup_identity(k, version) == NULL) { - Identity *id = xmalloc(sizeof(Identity)); + if (lifetime && !death) + death = time(NULL) + lifetime; + if ((id = lookup_identity(k, version)) == NULL) { + id = xmalloc(sizeof(Identity)); id->key = k; - id->comment = comment; TAILQ_INSERT_TAIL(&tab->idlist, id, next); /* Increment the number of identities. */ tab->nentries++; } else { key_free(k); - xfree(comment); + 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) +{ + 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) +process_add_smartcard_key(SocketEntry *e) { + char *sc_reader_id = NULL, *pin; + int i, type, version, success = 0, death = 0, confirm = 0; + Key **keys, *k; + Identity *id; Idtab *tab; - Key *n = NULL, *k = NULL; - char *sc_reader_id = NULL; - int success = 0; - sc_reader_id = buffer_get_string(&e->input, NULL); - k = sc_get_key(sc_reader_id); - xfree(sc_reader_id); + sc_reader_id = buffer_get_string(&e->request, NULL); + pin = buffer_get_string(&e->request, NULL); - if (k == NULL) { - error("sc_get_pubkey failed"); - 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_smartcard_key: " + "Unknown constraint type %d", type); + xfree(sc_reader_id); + xfree(pin); + goto send; + } } - success = 1; + if (lifetime && !death) + death = time(NULL) + lifetime; - tab = idtab_lookup(1); - k->type = KEY_RSA1; - if (lookup_identity(k, 1) == NULL) { - Identity *id = xmalloc(sizeof(Identity)); - n = key_new(KEY_RSA1); - BN_copy(n->rsa->n, k->rsa->n); - BN_copy(n->rsa->e, k->rsa->e); - RSA_set_method(n->rsa, sc_get_engine()); - id->key = n; - id->comment = xstrdup("rsa1 smartcard"); - TAILQ_INSERT_TAIL(&tab->idlist, id, next); - tab->nentries++; + 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; } - k->type = KEY_RSA; - tab = idtab_lookup(2); - if (lookup_identity(k, 2) == NULL) { - Identity *id = xmalloc(sizeof(Identity)); - n = key_new(KEY_RSA); - BN_copy(n->rsa->n, k->rsa->n); - BN_copy(n->rsa->e, k->rsa->e); - RSA_set_method(n->rsa, sc_get_engine()); - id->key = n; - id->comment = xstrdup("rsa smartcard"); - TAILQ_INSERT_TAIL(&tab->idlist, id, next); - tab->nentries++; + 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; } - key_free(k); + xfree(keys); send: buffer_put_int(&e->output, 1); buffer_put_char(&e->output, @@ -506,39 +677,37 @@ send: static void process_remove_smartcard_key(SocketEntry *e) { - Key *k = NULL; - int success = 0; - char *sc_reader_id = NULL; + 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->input, NULL); - k = sc_get_key(sc_reader_id); + 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 (k == NULL) { - error("sc_get_pubkey failed"); - } else { - Identity *id; - k->type = KEY_RSA1; - id = lookup_identity(k, 1); - if (id != NULL) { - Idtab *tab = idtab_lookup(1); + 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); - free_identity(id); tab->nentries--; - success = 1; - } - k->type = KEY_RSA; - id = lookup_identity(k, 2); - if (id != NULL) { - Idtab *tab = idtab_lookup(2); - TAILQ_REMOVE(&tab->idlist, id, next); free_identity(id); - tab->nentries--; 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); @@ -550,26 +719,50 @@ process_remove_smartcard_key(SocketEntry *e) static void process_message(SocketEntry *e) { - u_int msg_len; - u_int type; + 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_32BIT(cp); + msg_len = get_u32(cp); if (msg_len > 256 * 1024) { - shutdown(e->fd, SHUT_RDWR); - close(e->fd); - e->type = AUTH_UNUSED; + 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); - type = buffer_get_char(&e->input); + 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); @@ -578,6 +771,7 @@ process_message(SocketEntry *e) 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: @@ -594,6 +788,7 @@ process_message(SocketEntry *e) 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: @@ -604,6 +799,7 @@ 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: @@ -613,7 +809,7 @@ process_message(SocketEntry *e) default: /* Unknown message. Respond with failure. */ error("Unknown message %d", type); - buffer_clear(&e->input); + buffer_clear(&e->request); buffer_put_int(&e->output, 1); buffer_put_char(&e->output, SSH_AGENT_FAILURE); break; @@ -623,9 +819,9 @@ process_message(SocketEntry *e) 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)); + u_int i, old_alloc, new_alloc; + + set_nonblock(fd); if (fd > max_fd) max_fd = fd; @@ -633,30 +829,32 @@ new_socket(sock_type type, int 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); + sockets[i].type = type; 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++) + 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[old_alloc].type = type; + 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; } static int -prepare_select(fd_set **fdrp, fd_set **fdwp, int *fdl, int *nallocp) +prepare_select(fd_set **fdrp, fd_set **fdwp, int *fdl, u_int *nallocp, + struct timeval **tvpp) { - u_int i, sz; + u_int i, sz, deadline; int n = 0; + static struct timeval tv; for (i = 0; i < sockets_alloc; i++) { switch (sockets[i].type) { @@ -700,19 +898,32 @@ prepare_select(fd_set **fdrp, fd_set **fdwp, int *fdl, int *nallocp) 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) { - u_int i; - int len, sock; + struct sockaddr_un sunaddr; socklen_t slen; char buf[1024]; - struct sockaddr_un sunaddr; + int len, sock; + u_int i, orig_alloc; + uid_t euid; + gid_t egid; - for (i = 0; i < sockets_alloc; i++) + for (i = 0, orig_alloc = sockets_alloc; i < orig_alloc; i++) switch (sockets[i].type) { case AUTH_UNUSED: break; @@ -720,9 +931,23 @@ after_select(fd_set *readset, fd_set *writeset) if (FD_ISSET(sockets[i].fd, readset)) { slen = sizeof(sunaddr); sock = accept(sockets[i].fd, - (struct sockaddr *) &sunaddr, &slen); + (struct sockaddr *)&sunaddr, &slen); if (sock < 0) { - perror("accept from AUTH_SOCKET"); + 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); @@ -731,39 +956,27 @@ after_select(fd_set *readset, fd_set *writeset) 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); + 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) { - shutdown(sockets[i].fd, SHUT_RDWR); - close(sockets[i].fd); - sockets[i].type = AUTH_UNUSED; - buffer_free(&sockets[i].input); - buffer_free(&sockets[i].output); + 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); + len = read(sockets[i].fd, buf, sizeof(buf)); + if (len == -1 && (errno == EAGAIN || + errno == EWOULDBLOCK || + errno == EINTR)) + continue; if (len <= 0) { - shutdown(sockets[i].fd, SHUT_RDWR); - close(sockets[i].fd); - sockets[i].type = AUTH_UNUSED; - buffer_free(&sockets[i].input); - buffer_free(&sockets[i].output); + close_socket(&sockets[i]); break; } buffer_append(&sockets[i].input, buf, len); @@ -784,13 +997,14 @@ cleanup_socket(void) rmdir(socket_dir); } -static void +void cleanup_exit(int i) { cleanup_socket(); - exit(i); + _exit(i); } +/*ARGSUSED*/ static void cleanup_handler(int sig) { @@ -799,59 +1013,69 @@ cleanup_handler(int sig) } static void -check_parent_exists(int sig) +check_parent_exists(void) { - 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 */ + cleanup_socket(); + _exit(2); } - signal(SIGALRM, check_parent_exists); - alarm(10); - errno = save_errno; } static void usage(void) { - fprintf(stderr, "Usage: %s [options] [command [args ...]]\n", + 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) { - 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, 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 -#ifdef HAVE_CYGWIN int prev_mask; -#endif - pid_t pid; - char *shell, *format, *pidstr, pidstrbuf[1 + 3 * sizeof pid]; extern int optind; - fd_set *readsetp = NULL, *writesetp = NULL; + 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 = get_progname(av[0]); + __progname = ssh_get_progname(av[0]); init_rng(); seed_rng(); -#ifdef __GNU_LIBRARY__ - while ((ch = getopt(ac, av, "+cdks")) != -1) { -#else /* __GNU_LIBRARY__ */ - while ((ch = getopt(ac, av, "cdks")) != -1) { -#endif /* __GNU_LIBRARY__ */ + while ((ch = getopt(ac, av, "cdksa:t:")) != -1) { switch (ch) { case 'c': if (s_flag) @@ -871,6 +1095,15 @@ main(int ac, char **av) 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(); } @@ -881,22 +1114,26 @@ main(int ac, char **av) if (ac > 0 && (c_flag || k_flag || s_flag || d_flag)) usage(); - if (ac == 0 && !c_flag && !k_flag && !s_flag && !d_flag) { + if (ac == 0 && !c_flag && !s_flag) { shell = getenv("SHELL"); - if (shell != NULL && strncmp(shell + strlen(shell) - 3, "csh", 3) == 0) + 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 = atoi(pidstr); - if (pid < 1) { - fprintf(stderr, "%s=\"%s\", which is not a good PID\n", - SSH_AGENTPID_ENV_NAME, pidstr); + 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) { @@ -906,19 +1143,25 @@ main(int ac, char **av) 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); + printf("echo Agent pid %ld killed;\n", (long)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); + 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); } - 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 @@ -927,25 +1170,21 @@ main(int ac, char **av) 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)); -#ifdef HAVE_CYGWIN prev_mask = umask(0177); -#endif - if (bind(sock, (struct sockaddr *) & sunaddr, sizeof(sunaddr)) < 0) { + if (bind(sock, (struct sockaddr *) &sunaddr, sizeof(sunaddr)) < 0) { perror("bind"); -#ifdef HAVE_CYGWIN + *socket_name = '\0'; /* Don't unlink any existing file */ umask(prev_mask); -#endif cleanup_exit(1); } -#ifdef HAVE_CYGWIN umask(prev_mask); -#endif - if (listen(sock, 5) < 0) { + if (listen(sock, SSH_LISTEN_BACKLOG) < 0) { perror("listen"); cleanup_exit(1); } @@ -959,24 +1198,24 @@ main(int ac, char **av) 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 %d;\n", parent_pid); + printf("echo Agent pid %ld;\n", (long)parent_pid); goto skip; } pid = fork(); if (pid == -1) { perror("fork"); - exit(1); + cleanup_exit(1); } if (pid != 0) { /* Parent - execute the given command. */ close(sock); - snprintf(pidstrbuf, sizeof pidstrbuf, "%d", pid); + 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 %d;\n", pid); + printf("echo Agent pid %ld;\n", (long)pid); exit(0); } if (setenv(SSH_AUTHSOCKET_ENV_NAME, socket_name, 1) == -1 || @@ -988,36 +1227,37 @@ main(int ac, char **av) perror(av[0]); exit(1); } + /* child */ + log_init(__progname, SYSLOG_LEVEL_INFO, SYSLOG_FACILITY_AUTH, 0); if (setsid() == -1) { - perror("setsid"); + error("setsid: %s", strerror(errno)); cleanup_exit(1); } (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 */ rlim.rlim_cur = rlim.rlim_max = 0; if (setrlimit(RLIMIT_CORE, &rlim) < 0) { - perror("setrlimit rlimit_core failed"); + error("setrlimit RLIMIT_CORE: %s", strerror(errno)); cleanup_exit(1); } #endif skip: - if (atexit(cleanup_socket) < 0) { - perror("atexit"); - cleanup_exit(1); - } new_socket(AUTH_SOCKET, sock); - if (ac > 0) { - signal(SIGALRM, check_parent_exists); - alarm(10); - } + if (ac > 0) + parent_alive_interval = 10; idtab_init(); if (!d_flag) signal(SIGINT, SIG_IGN); @@ -1027,13 +1267,18 @@ skip: nalloc = 0; while (1) { - prepare_select(&readsetp, &writesetp, &max_fd, &nalloc); - if (select(max_fd + 1, readsetp, writesetp, NULL, NULL) < 0) { - if (errno == EINTR) + 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; - exit(1); - } - after_select(readsetp, writesetp); + fatal("select: %s", strerror(saved_errno)); + } else if (result > 0) + after_select(readsetp, writesetp); } /* NOTREACHED */ }