872 lines
21 KiB
C
872 lines
21 KiB
C
/* $OpenBSD: ssh-agent.c,v 1.54 2001/04/03 13:56:11 stevesk Exp $ */
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/*
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* Author: Tatu Ylonen <ylo@cs.hut.fi>
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* Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
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* All rights reserved
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* The authentication agent program.
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*
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* As far as I am concerned, the code I have written for this software
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* can be used freely for any purpose. Any derived versions of this
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* software must be clearly marked as such, and if the derived work is
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* incompatible with the protocol description in the RFC file, it must be
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* called by a name other than "ssh" or "Secure Shell".
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*
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* SSH2 implementation,
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* Copyright (c) 2000 Markus Friedl. All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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*
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* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
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* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
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* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
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* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
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* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
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* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
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* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
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* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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*/
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#include "includes.h"
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RCSID("$OpenBSD: ssh-agent.c,v 1.54 2001/04/03 13:56:11 stevesk Exp $");
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#include <openssl/evp.h>
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#include <openssl/md5.h>
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#include "ssh.h"
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#include "rsa.h"
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#include "buffer.h"
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#include "bufaux.h"
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#include "xmalloc.h"
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#include "packet.h"
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#include "getput.h"
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#include "mpaux.h"
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#include "key.h"
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#include "authfd.h"
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#include "cipher.h"
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#include "kex.h"
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#include "compat.h"
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#include "log.h"
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typedef struct {
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int fd;
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enum {
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AUTH_UNUSED, AUTH_SOCKET, AUTH_CONNECTION
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} type;
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Buffer input;
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Buffer output;
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} SocketEntry;
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u_int sockets_alloc = 0;
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SocketEntry *sockets = NULL;
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typedef struct {
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Key *key;
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char *comment;
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} Identity;
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typedef struct {
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int nentries;
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Identity *identities;
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} Idtab;
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/* private key table, one per protocol version */
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Idtab idtable[3];
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int max_fd = 0;
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/* pid of shell == parent of agent */
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pid_t parent_pid = -1;
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/* pathname and directory for AUTH_SOCKET */
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char socket_name[1024];
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char socket_dir[1024];
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extern char *__progname;
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int prepare_select(fd_set **, fd_set **, int *);
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void
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idtab_init(void)
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{
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int i;
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for (i = 0; i <=2; i++){
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idtable[i].identities = NULL;
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idtable[i].nentries = 0;
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}
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}
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/* return private key table for requested protocol version */
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Idtab *
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idtab_lookup(int version)
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{
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if (version < 1 || version > 2)
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fatal("internal error, bad protocol version %d", version);
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return &idtable[version];
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}
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/* return matching private key for given public key */
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Key *
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lookup_private_key(Key *key, int *idx, int version)
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{
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int i;
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Idtab *tab = idtab_lookup(version);
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for (i = 0; i < tab->nentries; i++) {
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if (key_equal(key, tab->identities[i].key)) {
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if (idx != NULL)
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*idx = i;
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return tab->identities[i].key;
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}
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}
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return NULL;
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}
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/* send list of supported public keys to 'client' */
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void
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process_request_identities(SocketEntry *e, int version)
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{
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Idtab *tab = idtab_lookup(version);
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Buffer msg;
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int i;
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buffer_init(&msg);
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buffer_put_char(&msg, (version == 1) ?
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SSH_AGENT_RSA_IDENTITIES_ANSWER : SSH2_AGENT_IDENTITIES_ANSWER);
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buffer_put_int(&msg, tab->nentries);
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for (i = 0; i < tab->nentries; i++) {
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Identity *id = &tab->identities[i];
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if (id->key->type == KEY_RSA1) {
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buffer_put_int(&msg, BN_num_bits(id->key->rsa->n));
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buffer_put_bignum(&msg, id->key->rsa->e);
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buffer_put_bignum(&msg, id->key->rsa->n);
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} else {
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u_char *blob;
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u_int blen;
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key_to_blob(id->key, &blob, &blen);
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buffer_put_string(&msg, blob, blen);
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xfree(blob);
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}
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buffer_put_cstring(&msg, id->comment);
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}
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buffer_put_int(&e->output, buffer_len(&msg));
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buffer_append(&e->output, buffer_ptr(&msg), buffer_len(&msg));
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buffer_free(&msg);
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}
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/* ssh1 only */
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void
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process_authentication_challenge1(SocketEntry *e)
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{
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Key *key, *private;
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BIGNUM *challenge;
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int i, len;
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Buffer msg;
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MD5_CTX md;
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u_char buf[32], mdbuf[16], session_id[16];
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u_int response_type;
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buffer_init(&msg);
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key = key_new(KEY_RSA1);
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challenge = BN_new();
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buffer_get_int(&e->input); /* ignored */
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buffer_get_bignum(&e->input, key->rsa->e);
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buffer_get_bignum(&e->input, key->rsa->n);
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buffer_get_bignum(&e->input, challenge);
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/* Only protocol 1.1 is supported */
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if (buffer_len(&e->input) == 0)
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goto failure;
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buffer_get(&e->input, (char *) session_id, 16);
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response_type = buffer_get_int(&e->input);
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if (response_type != 1)
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goto failure;
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private = lookup_private_key(key, NULL, 1);
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if (private != NULL) {
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/* Decrypt the challenge using the private key. */
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if (rsa_private_decrypt(challenge, challenge, private->rsa) <= 0)
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goto failure;
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/* The response is MD5 of decrypted challenge plus session id. */
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len = BN_num_bytes(challenge);
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if (len <= 0 || len > 32) {
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log("process_authentication_challenge: bad challenge length %d", len);
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goto failure;
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}
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memset(buf, 0, 32);
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BN_bn2bin(challenge, buf + 32 - len);
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MD5_Init(&md);
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MD5_Update(&md, buf, 32);
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MD5_Update(&md, session_id, 16);
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MD5_Final(mdbuf, &md);
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/* Send the response. */
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buffer_put_char(&msg, SSH_AGENT_RSA_RESPONSE);
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for (i = 0; i < 16; i++)
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buffer_put_char(&msg, mdbuf[i]);
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goto send;
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}
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failure:
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/* Unknown identity or protocol error. Send failure. */
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buffer_put_char(&msg, SSH_AGENT_FAILURE);
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send:
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buffer_put_int(&e->output, buffer_len(&msg));
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buffer_append(&e->output, buffer_ptr(&msg), buffer_len(&msg));
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key_free(key);
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BN_clear_free(challenge);
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buffer_free(&msg);
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}
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/* ssh2 only */
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void
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process_sign_request2(SocketEntry *e)
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{
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extern int datafellows;
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Key *key, *private;
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u_char *blob, *data, *signature = NULL;
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u_int blen, dlen, slen = 0;
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int flags;
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Buffer msg;
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int ok = -1;
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datafellows = 0;
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blob = buffer_get_string(&e->input, &blen);
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data = buffer_get_string(&e->input, &dlen);
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flags = buffer_get_int(&e->input);
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if (flags & SSH_AGENT_OLD_SIGNATURE)
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datafellows = SSH_BUG_SIGBLOB;
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key = key_from_blob(blob, blen);
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if (key != NULL) {
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private = lookup_private_key(key, NULL, 2);
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if (private != NULL)
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ok = key_sign(private, &signature, &slen, data, dlen);
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}
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key_free(key);
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buffer_init(&msg);
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if (ok == 0) {
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buffer_put_char(&msg, SSH2_AGENT_SIGN_RESPONSE);
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buffer_put_string(&msg, signature, slen);
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} else {
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buffer_put_char(&msg, SSH_AGENT_FAILURE);
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}
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buffer_put_int(&e->output, buffer_len(&msg));
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buffer_append(&e->output, buffer_ptr(&msg),
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buffer_len(&msg));
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buffer_free(&msg);
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xfree(data);
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xfree(blob);
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if (signature != NULL)
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xfree(signature);
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}
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/* shared */
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void
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process_remove_identity(SocketEntry *e, int version)
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{
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Key *key = NULL, *private;
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u_char *blob;
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u_int blen;
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u_int bits;
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int success = 0;
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switch(version){
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case 1:
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key = key_new(KEY_RSA1);
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bits = buffer_get_int(&e->input);
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buffer_get_bignum(&e->input, key->rsa->e);
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buffer_get_bignum(&e->input, key->rsa->n);
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if (bits != key_size(key))
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log("Warning: identity keysize mismatch: actual %d, announced %d",
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key_size(key), bits);
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break;
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case 2:
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blob = buffer_get_string(&e->input, &blen);
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key = key_from_blob(blob, blen);
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xfree(blob);
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break;
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}
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if (key != NULL) {
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int idx;
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private = lookup_private_key(key, &idx, version);
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if (private != NULL) {
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/*
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* We have this key. Free the old key. Since we
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* don\'t want to leave empty slots in the middle of
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* the array, we actually free the key there and move
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* all the entries between the empty slot and the end
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* of the array.
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*/
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Idtab *tab = idtab_lookup(version);
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key_free(tab->identities[idx].key);
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xfree(tab->identities[idx].comment);
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if (tab->nentries < 1)
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fatal("process_remove_identity: "
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"internal error: tab->nentries %d",
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tab->nentries);
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if (idx != tab->nentries - 1) {
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int i;
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for (i = idx; i < tab->nentries - 1; i++)
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tab->identities[i] = tab->identities[i+1];
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}
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tab->identities[tab->nentries - 1].key = NULL;
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tab->identities[tab->nentries - 1].comment = NULL;
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tab->nentries--;
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success = 1;
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}
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key_free(key);
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}
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buffer_put_int(&e->output, 1);
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buffer_put_char(&e->output,
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success ? SSH_AGENT_SUCCESS : SSH_AGENT_FAILURE);
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}
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void
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process_remove_all_identities(SocketEntry *e, int version)
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{
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u_int i;
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Idtab *tab = idtab_lookup(version);
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/* Loop over all identities and clear the keys. */
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for (i = 0; i < tab->nentries; i++) {
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key_free(tab->identities[i].key);
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xfree(tab->identities[i].comment);
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}
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/* Mark that there are no identities. */
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tab->nentries = 0;
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/* Send success. */
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buffer_put_int(&e->output, 1);
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buffer_put_char(&e->output, SSH_AGENT_SUCCESS);
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return;
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}
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void
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process_add_identity(SocketEntry *e, int version)
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{
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Key *k = NULL;
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char *type_name;
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char *comment;
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int type, success = 0;
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Idtab *tab = idtab_lookup(version);
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switch (version) {
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case 1:
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k = key_new_private(KEY_RSA1);
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buffer_get_int(&e->input); /* ignored */
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buffer_get_bignum(&e->input, k->rsa->n);
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buffer_get_bignum(&e->input, k->rsa->e);
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buffer_get_bignum(&e->input, k->rsa->d);
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buffer_get_bignum(&e->input, k->rsa->iqmp);
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/* SSH and SSL have p and q swapped */
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buffer_get_bignum(&e->input, k->rsa->q); /* p */
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buffer_get_bignum(&e->input, k->rsa->p); /* q */
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/* Generate additional parameters */
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generate_additional_parameters(k->rsa);
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break;
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case 2:
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type_name = buffer_get_string(&e->input, NULL);
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type = key_type_from_name(type_name);
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xfree(type_name);
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switch(type) {
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case KEY_DSA:
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k = key_new_private(type);
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buffer_get_bignum2(&e->input, k->dsa->p);
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buffer_get_bignum2(&e->input, k->dsa->q);
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buffer_get_bignum2(&e->input, k->dsa->g);
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buffer_get_bignum2(&e->input, k->dsa->pub_key);
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buffer_get_bignum2(&e->input, k->dsa->priv_key);
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break;
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case KEY_RSA:
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k = key_new_private(type);
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buffer_get_bignum2(&e->input, k->rsa->n);
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buffer_get_bignum2(&e->input, k->rsa->e);
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buffer_get_bignum2(&e->input, k->rsa->d);
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buffer_get_bignum2(&e->input, k->rsa->iqmp);
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buffer_get_bignum2(&e->input, k->rsa->p);
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buffer_get_bignum2(&e->input, k->rsa->q);
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/* Generate additional parameters */
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generate_additional_parameters(k->rsa);
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break;
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default:
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buffer_clear(&e->input);
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goto send;
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}
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break;
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}
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comment = buffer_get_string(&e->input, NULL);
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if (k == NULL) {
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xfree(comment);
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goto send;
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}
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success = 1;
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if (lookup_private_key(k, NULL, version) == NULL) {
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if (tab->nentries == 0)
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tab->identities = xmalloc(sizeof(Identity));
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else
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tab->identities = xrealloc(tab->identities,
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(tab->nentries + 1) * sizeof(Identity));
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tab->identities[tab->nentries].key = k;
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tab->identities[tab->nentries].comment = comment;
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/* Increment the number of identities. */
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tab->nentries++;
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} else {
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key_free(k);
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xfree(comment);
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}
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send:
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buffer_put_int(&e->output, 1);
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buffer_put_char(&e->output,
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success ? SSH_AGENT_SUCCESS : SSH_AGENT_FAILURE);
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}
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/* dispatch incoming messages */
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void
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process_message(SocketEntry *e)
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{
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u_int msg_len;
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u_int type;
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u_char *cp;
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if (buffer_len(&e->input) < 5)
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return; /* Incomplete message. */
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cp = (u_char *) buffer_ptr(&e->input);
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msg_len = GET_32BIT(cp);
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if (msg_len > 256 * 1024) {
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shutdown(e->fd, SHUT_RDWR);
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close(e->fd);
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e->type = AUTH_UNUSED;
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return;
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}
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if (buffer_len(&e->input) < msg_len + 4)
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return;
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buffer_consume(&e->input, 4);
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type = buffer_get_char(&e->input);
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switch (type) {
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/* ssh1 */
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case SSH_AGENTC_RSA_CHALLENGE:
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process_authentication_challenge1(e);
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break;
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case SSH_AGENTC_REQUEST_RSA_IDENTITIES:
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process_request_identities(e, 1);
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break;
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case SSH_AGENTC_ADD_RSA_IDENTITY:
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process_add_identity(e, 1);
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break;
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case SSH_AGENTC_REMOVE_RSA_IDENTITY:
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process_remove_identity(e, 1);
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break;
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case SSH_AGENTC_REMOVE_ALL_RSA_IDENTITIES:
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process_remove_all_identities(e, 1);
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break;
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/* ssh2 */
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case SSH2_AGENTC_SIGN_REQUEST:
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process_sign_request2(e);
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break;
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case SSH2_AGENTC_REQUEST_IDENTITIES:
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process_request_identities(e, 2);
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break;
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case SSH2_AGENTC_ADD_IDENTITY:
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process_add_identity(e, 2);
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break;
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case SSH2_AGENTC_REMOVE_IDENTITY:
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process_remove_identity(e, 2);
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break;
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case SSH2_AGENTC_REMOVE_ALL_IDENTITIES:
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process_remove_all_identities(e, 2);
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break;
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default:
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/* Unknown message. Respond with failure. */
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error("Unknown message %d", type);
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buffer_clear(&e->input);
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buffer_put_int(&e->output, 1);
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buffer_put_char(&e->output, SSH_AGENT_FAILURE);
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break;
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}
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}
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void
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new_socket(int type, int fd)
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{
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u_int i, old_alloc;
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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
|
|
prepare_select(fd_set **fdrp, fd_set **fdwp, int *fdl)
|
|
{
|
|
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 || n > *fdl) {
|
|
if (*fdrp)
|
|
xfree(*fdrp);
|
|
if (*fdwp)
|
|
xfree(*fdwp);
|
|
*fdrp = xmalloc(sz);
|
|
*fdwp = xmalloc(sz);
|
|
*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);
|
|
}
|
|
|
|
void
|
|
after_select(fd_set *readset, fd_set *writeset)
|
|
{
|
|
u_int i;
|
|
int len, sock;
|
|
socklen_t slen;
|
|
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)) {
|
|
slen = sizeof(sunaddr);
|
|
sock = accept(sockets[i].fd,
|
|
(struct sockaddr *) &sunaddr, &slen);
|
|
if (sock < 0) {
|
|
perror("accept from AUTH_SOCKET");
|
|
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) {
|
|
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);
|
|
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) {
|
|
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);
|
|
break;
|
|
}
|
|
buffer_append(&sockets[i].input, buf, len);
|
|
process_message(&sockets[i]);
|
|
}
|
|
break;
|
|
default:
|
|
fatal("Unknown type %d", sockets[i].type);
|
|
}
|
|
}
|
|
|
|
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"); */
|
|
exit(1);
|
|
}
|
|
signal(SIGALRM, check_parent_exists);
|
|
alarm(10);
|
|
errno = save_errno;
|
|
}
|
|
|
|
void
|
|
cleanup_socket(void)
|
|
{
|
|
if (socket_name[0])
|
|
unlink(socket_name);
|
|
if (socket_dir[0])
|
|
rmdir(socket_dir);
|
|
}
|
|
|
|
void
|
|
cleanup_exit(int i)
|
|
{
|
|
cleanup_socket();
|
|
exit(i);
|
|
}
|
|
|
|
void
|
|
cleanup_handler(int sig)
|
|
{
|
|
cleanup_socket();
|
|
_exit(2);
|
|
}
|
|
|
|
void
|
|
usage(void)
|
|
{
|
|
fprintf(stderr, "ssh-agent version %s\n", SSH_VERSION);
|
|
fprintf(stderr, "Usage: %s [-c | -s] [-k] [command {args...]]\n",
|
|
__progname);
|
|
exit(1);
|
|
}
|
|
|
|
int
|
|
main(int ac, char **av)
|
|
{
|
|
int sock, c_flag = 0, k_flag = 0, s_flag = 0, ch;
|
|
struct sockaddr_un sunaddr;
|
|
struct rlimit rlim;
|
|
pid_t pid;
|
|
char *shell, *format, *pidstr, pidstrbuf[1 + 3 * sizeof pid];
|
|
extern int optind;
|
|
fd_set *readsetp = NULL, *writesetp = NULL;
|
|
|
|
SSLeay_add_all_algorithms();
|
|
|
|
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) {
|
|
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);
|
|
}
|
|
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);
|
|
}
|
|
close(0);
|
|
close(1);
|
|
close(2);
|
|
|
|
/* 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");
|
|
cleanup_exit(1);
|
|
}
|
|
if (setsid() == -1) {
|
|
perror("setsid");
|
|
cleanup_exit(1);
|
|
}
|
|
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);
|
|
}
|
|
idtab_init();
|
|
signal(SIGINT, SIG_IGN);
|
|
signal(SIGPIPE, SIG_IGN);
|
|
signal(SIGHUP, cleanup_handler);
|
|
signal(SIGTERM, cleanup_handler);
|
|
while (1) {
|
|
prepare_select(&readsetp, &writesetp, &max_fd);
|
|
if (select(max_fd + 1, readsetp, writesetp, NULL, NULL) < 0) {
|
|
if (errno == EINTR)
|
|
continue;
|
|
exit(1);
|
|
}
|
|
after_select(readsetp, writesetp);
|
|
}
|
|
/* NOTREACHED */
|
|
}
|