crypto/openssh/authfd.c

   1 /* $OpenBSD: authfd.c,v 1.100 2015/12/04 16:41:28 markus Exp $ */
   2 /*
   3  * Author: Tatu Ylonen <ylo@cs.hut.fi>
   4  * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
   5  *                    All rights reserved
   6  * Functions for connecting the local authentication agent.
   7  *
   8  * As far as I am concerned, the code I have written for this software
   9  * can be used freely for any purpose.  Any derived versions of this
  10  * software must be clearly marked as such, and if the derived work is
  11  * incompatible with the protocol description in the RFC file, it must be
  12  * called by a name other than "ssh" or "Secure Shell".
  13  *
  14  * SSH2 implementation,
  15  * Copyright (c) 2000 Markus Friedl.  All rights reserved.
  16  *
  17  * Redistribution and use in source and binary forms, with or without
  18  * modification, are permitted provided that the following conditions
  19  * are met:
  20  * 1. Redistributions of source code must retain the above copyright
  21  *    notice, this list of conditions and the following disclaimer.
  22  * 2. Redistributions in binary form must reproduce the above copyright
  23  *    notice, this list of conditions and the following disclaimer in the
  24  *    documentation and/or other materials provided with the distribution.
  25  *
  26  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
  27  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  28  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
  29  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
  30  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  31  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  32  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  33  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  34  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  35  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  36  */
  37
  38 #include "includes.h"
  39
  40 #include <sys/types.h>
  41 #include <sys/un.h>
  42 #include <sys/socket.h>
  43
  44 #include <fcntl.h>
  45 #include <stdlib.h>
  46 #include <signal.h>
  47 #include <stdarg.h>
  48 #include <string.h>
  49 #include <unistd.h>
  50 #include <errno.h>
  51
  52 #include "xmalloc.h"
  53 #include "ssh.h"
  54 #include "rsa.h"
  55 #include "sshbuf.h"
  56 #include "sshkey.h"
  57 #include "authfd.h"
  58 #include "cipher.h"
  59 #include "compat.h"
  60 #include "log.h"
  61 #include "atomicio.h"
  62 #include "misc.h"
  63 #include "ssherr.h"
  64
  65 #define MAX_AGENT_IDENTITIES    2048            /* Max keys in agent reply */
  66 #define MAX_AGENT_REPLY_LEN     (256 * 1024)    /* Max bytes in agent reply */
  67
  68 /* macro to check for "agent failure" message */
  69 #define agent_failed(x) \
  70     ((x == SSH_AGENT_FAILURE) || \
  71     (x == SSH_COM_AGENT2_FAILURE) || \
  72     (x == SSH2_AGENT_FAILURE))
  73
  74 /* Convert success/failure response from agent to a err.h status */
  75 static int
  76 decode_reply(u_char type)
  77 {
  78         if (agent_failed(type))
  79                 return SSH_ERR_AGENT_FAILURE;
  80         else if (type == SSH_AGENT_SUCCESS)
  81                 return 0;
  82         else
  83                 return SSH_ERR_INVALID_FORMAT;
  84 }
  85
  86 /* Returns the number of the authentication fd, or -1 if there is none. */
  87 int
  88 ssh_get_authentication_socket(int *fdp)
  89 {
  90         const char *authsocket;
  91         int sock, oerrno;
  92         struct sockaddr_un sunaddr;
  93
  94         if (fdp != NULL)
  95                 *fdp = -1;
  96
  97         authsocket = getenv(SSH_AUTHSOCKET_ENV_NAME);
  98         if (!authsocket)
  99                 return SSH_ERR_AGENT_NOT_PRESENT;
 100
 101         memset(&sunaddr, 0, sizeof(sunaddr));
 102         sunaddr.sun_family = AF_UNIX;
 103         strlcpy(sunaddr.sun_path, authsocket, sizeof(sunaddr.sun_path));
 104
 105         if ((sock = socket(AF_UNIX, SOCK_STREAM, 0)) < 0)
 106                 return SSH_ERR_SYSTEM_ERROR;
 107
 108         /* close on exec */
 109         if (fcntl(sock, F_SETFD, FD_CLOEXEC) == -1 ||
 110             connect(sock, (struct sockaddr *)&sunaddr, sizeof(sunaddr)) < 0) {
 111                 oerrno = errno;
 112                 close(sock);
 113                 errno = oerrno;
 114                 return SSH_ERR_SYSTEM_ERROR;
 115         }
 116         if (fdp != NULL)
 117                 *fdp = sock;
 118         else
 119                 close(sock);
 120         return 0;
 121 }
 122
 123 /* Communicate with agent: send request and read reply */
 124 static int
 125 ssh_request_reply(int sock, struct sshbuf *request, struct sshbuf *reply)
 126 {
 127         int r;
 128         size_t l, len;
 129         char buf[1024];
 130
 131         /* Get the length of the message, and format it in the buffer. */
 132         len = sshbuf_len(request);
 133         put_u32(buf, len);
 134
 135         /* Send the length and then the packet to the agent. */
 136         if (atomicio(vwrite, sock, buf, 4) != 4 ||
 137             atomicio(vwrite, sock, (u_char *)sshbuf_ptr(request),
 138             sshbuf_len(request)) != sshbuf_len(request))
 139                 return SSH_ERR_AGENT_COMMUNICATION;
 140         /*
 141          * Wait for response from the agent.  First read the length of the
 142          * response packet.
 143          */
 144         if (atomicio(read, sock, buf, 4) != 4)
 145             return SSH_ERR_AGENT_COMMUNICATION;
 146
 147         /* Extract the length, and check it for sanity. */
 148         len = get_u32(buf);
 149         if (len > MAX_AGENT_REPLY_LEN)
 150                 return SSH_ERR_INVALID_FORMAT;
 151
 152         /* Read the rest of the response in to the buffer. */
 153         sshbuf_reset(reply);
 154         while (len > 0) {
 155                 l = len;
 156                 if (l > sizeof(buf))
 157                         l = sizeof(buf);
 158                 if (atomicio(read, sock, buf, l) != l)
 159                         return SSH_ERR_AGENT_COMMUNICATION;
 160                 if ((r = sshbuf_put(reply, buf, l)) != 0)
 161                         return r;
 162                 len -= l;
 163         }
 164         return 0;
 165 }
 166
 167 /*
 168  * Closes the agent socket if it should be closed (depends on how it was
 169  * obtained).  The argument must have been returned by
 170  * ssh_get_authentication_socket().
 171  */
 172 void
 173 ssh_close_authentication_socket(int sock)
 174 {
 175         if (getenv(SSH_AUTHSOCKET_ENV_NAME))
 176                 close(sock);
 177 }
 178
 179 /* Lock/unlock agent */
 180 int
 181 ssh_lock_agent(int sock, int lock, const char *password)
 182 {
 183         int r;
 184         u_char type = lock ? SSH_AGENTC_LOCK : SSH_AGENTC_UNLOCK;
 185         struct sshbuf *msg;
 186
 187         if ((msg = sshbuf_new()) == NULL)
 188                 return SSH_ERR_ALLOC_FAIL;
 189         if ((r = sshbuf_put_u8(msg, type)) != 0 ||
 190             (r = sshbuf_put_cstring(msg, password)) != 0)
 191                 goto out;
 192         if ((r = ssh_request_reply(sock, msg, msg)) != 0)
 193                 goto out;
 194         if ((r = sshbuf_get_u8(msg, &type)) != 0)
 195                 goto out;
 196         r = decode_reply(type);
 197  out:
 198         sshbuf_free(msg);
 199         return r;
 200 }
 201
 202 #ifdef WITH_SSH1
 203 static int
 204 deserialise_identity1(struct sshbuf *ids, struct sshkey **keyp, char **commentp)
 205 {
 206         struct sshkey *key;
 207         int r, keybits;
 208         u_int32_t bits;
 209         char *comment = NULL;
 210
 211         if ((key = sshkey_new(KEY_RSA1)) == NULL)
 212                 return SSH_ERR_ALLOC_FAIL;
 213         if ((r = sshbuf_get_u32(ids, &bits)) != 0 ||
 214             (r = sshbuf_get_bignum1(ids, key->rsa->e)) != 0 ||
 215             (r = sshbuf_get_bignum1(ids, key->rsa->n)) != 0 ||
 216             (r = sshbuf_get_cstring(ids, &comment, NULL)) != 0)
 217                 goto out;
 218         keybits = BN_num_bits(key->rsa->n);
 219         /* XXX previously we just warned here. I think we should be strict */
 220         if (keybits < 0 || bits != (u_int)keybits) {
 221                 r = SSH_ERR_KEY_BITS_MISMATCH;
 222                 goto out;
 223         }
 224         if (keyp != NULL) {
 225                 *keyp = key;
 226                 key = NULL;
 227         }
 228         if (commentp != NULL) {
 229                 *commentp = comment;
 230                 comment = NULL;
 231         }
 232         r = 0;
 233  out:
 234         sshkey_free(key);
 235         free(comment);
 236         return r;
 237 }
 238 #endif
 239
 240 static int
 241 deserialise_identity2(struct sshbuf *ids, struct sshkey **keyp, char **commentp)
 242 {
 243         int r;
 244         char *comment = NULL;
 245         const u_char *blob;
 246         size_t blen;
 247
 248         if ((r = sshbuf_get_string_direct(ids, &blob, &blen)) != 0 ||
 249             (r = sshbuf_get_cstring(ids, &comment, NULL)) != 0)
 250                 goto out;
 251         if ((r = sshkey_from_blob(blob, blen, keyp)) != 0)
 252                 goto out;
 253         if (commentp != NULL) {
 254                 *commentp = comment;
 255                 comment = NULL;
 256         }
 257         r = 0;
 258  out:
 259         free(comment);
 260         return r;
 261 }
 262
 263 /*
 264  * Fetch list of identities held by the agent.
 265  */
 266 int
 267 ssh_fetch_identitylist(int sock, int version, struct ssh_identitylist **idlp)
 268 {
 269         u_char type, code1 = 0, code2 = 0;
 270         u_int32_t num, i;
 271         struct sshbuf *msg;
 272         struct ssh_identitylist *idl = NULL;
 273         int r;
 274
 275         /* Determine request and expected response types */
 276         switch (version) {
 277         case 1:
 278                 code1 = SSH_AGENTC_REQUEST_RSA_IDENTITIES;
 279                 code2 = SSH_AGENT_RSA_IDENTITIES_ANSWER;
 280                 break;
 281         case 2:
 282                 code1 = SSH2_AGENTC_REQUEST_IDENTITIES;
 283                 code2 = SSH2_AGENT_IDENTITIES_ANSWER;
 284                 break;
 285         default:
 286                 return SSH_ERR_INVALID_ARGUMENT;
 287         }
 288
 289         /*
 290          * Send a message to the agent requesting for a list of the
 291          * identities it can represent.
 292          */
 293         if ((msg = sshbuf_new()) == NULL)
 294                 return SSH_ERR_ALLOC_FAIL;
 295         if ((r = sshbuf_put_u8(msg, code1)) != 0)
 296                 goto out;
 297
 298         if ((r = ssh_request_reply(sock, msg, msg)) != 0)
 299                 goto out;
 300
 301         /* Get message type, and verify that we got a proper answer. */
 302         if ((r = sshbuf_get_u8(msg, &type)) != 0)
 303                 goto out;
 304         if (agent_failed(type)) {
 305                 r = SSH_ERR_AGENT_FAILURE;
 306                 goto out;
 307         } else if (type != code2) {
 308                 r = SSH_ERR_INVALID_FORMAT;
 309                 goto out;
 310         }
 311
 312         /* Get the number of entries in the response and check it for sanity. */
 313         if ((r = sshbuf_get_u32(msg, &num)) != 0)
 314                 goto out;
 315         if (num > MAX_AGENT_IDENTITIES) {
 316                 r = SSH_ERR_INVALID_FORMAT;
 317                 goto out;
 318         }
 319         if (num == 0) {
 320                 r = SSH_ERR_AGENT_NO_IDENTITIES;
 321                 goto out;
 322         }
 323
 324         /* Deserialise the response into a list of keys/comments */
 325         if ((idl = calloc(1, sizeof(*idl))) == NULL ||
 326             (idl->keys = calloc(num, sizeof(*idl->keys))) == NULL ||
 327             (idl->comments = calloc(num, sizeof(*idl->comments))) == NULL) {
 328                 r = SSH_ERR_ALLOC_FAIL;
 329                 goto out;
 330         }
 331         for (i = 0; i < num;) {
 332                 switch (version) {
 333                 case 1:
 334 #ifdef WITH_SSH1
 335                         if ((r = deserialise_identity1(msg,
 336                             &(idl->keys[i]), &(idl->comments[i]))) != 0)
 337                                 goto out;
 338 #endif
 339                         break;
 340                 case 2:
 341                         if ((r = deserialise_identity2(msg,
 342                             &(idl->keys[i]), &(idl->comments[i]))) != 0) {
 343                                 if (r == SSH_ERR_KEY_TYPE_UNKNOWN) {
 344                                         /* Gracefully skip unknown key types */
 345                                         num--;
 346                                         continue;
 347                                 } else
 348                                         goto out;
 349                         }
 350                         break;
 351                 }
 352                 i++;
 353         }
 354         idl->nkeys = num;
 355         *idlp = idl;
 356         idl = NULL;
 357         r = 0;
 358  out:
 359         sshbuf_free(msg);
 360         if (idl != NULL)
 361                 ssh_free_identitylist(idl);
 362         return r;
 363 }
 364
 365 void
 366 ssh_free_identitylist(struct ssh_identitylist *idl)
 367 {
 368         size_t i;
 369
 370         if (idl == NULL)
 371                 return;
 372         for (i = 0; i < idl->nkeys; i++) {
 373                 if (idl->keys != NULL)
 374                         sshkey_free(idl->keys[i]);
 375                 if (idl->comments != NULL)
 376                         free(idl->comments[i]);
 377         }
 378         free(idl);
 379 }
 380
 381 /*
 382  * Sends a challenge (typically from a server via ssh(1)) to the agent,
 383  * and waits for a response from the agent.
 384  * Returns true (non-zero) if the agent gave the correct answer, zero
 385  * otherwise.
 386  */
 387
 388 #ifdef WITH_SSH1
 389 int
 390 ssh_decrypt_challenge(int sock, struct sshkey* key, BIGNUM *challenge,
 391     u_char session_id[16], u_char response[16])
 392 {
 393         struct sshbuf *msg;
 394         int r;
 395         u_char type;
 396
 397         if (key->type != KEY_RSA1)
 398                 return SSH_ERR_INVALID_ARGUMENT;
 399         if ((msg = sshbuf_new()) == NULL)
 400                 return SSH_ERR_ALLOC_FAIL;
 401         if ((r = sshbuf_put_u8(msg, SSH_AGENTC_RSA_CHALLENGE)) != 0 ||
 402             (r = sshbuf_put_u32(msg, BN_num_bits(key->rsa->n))) != 0 ||
 403             (r = sshbuf_put_bignum1(msg, key->rsa->e)) != 0 ||
 404             (r = sshbuf_put_bignum1(msg, key->rsa->n)) != 0 ||
 405             (r = sshbuf_put_bignum1(msg, challenge)) != 0 ||
 406             (r = sshbuf_put(msg, session_id, 16)) != 0 ||
 407             (r = sshbuf_put_u32(msg, 1)) != 0) /* Response type for proto 1.1 */
 408                 goto out;
 409         if ((r = ssh_request_reply(sock, msg, msg)) != 0)
 410                 goto out;
 411         if ((r = sshbuf_get_u8(msg, &type)) != 0)
 412                 goto out;
 413         if (agent_failed(type)) {
 414                 r = SSH_ERR_AGENT_FAILURE;
 415                 goto out;
 416         } else if (type != SSH_AGENT_RSA_RESPONSE) {
 417                 r = SSH_ERR_INVALID_FORMAT;
 418                 goto out;
 419         }
 420         if ((r = sshbuf_get(msg, response, 16)) != 0)
 421                 goto out;
 422         r = 0;
 423  out:
 424         sshbuf_free(msg);
 425         return r;
 426 }
 427 #endif
 428
 429 /* encode signature algoritm in flag bits, so we can keep the msg format */
 430 static u_int
 431 agent_encode_alg(struct sshkey *key, const char *alg)
 432 {
 433         if (alg != NULL && key->type == KEY_RSA) {
 434                 if (strcmp(alg, "rsa-sha2-256") == 0)
 435                         return SSH_AGENT_RSA_SHA2_256;
 436                 else if (strcmp(alg, "rsa-sha2-512") == 0)
 437                         return SSH_AGENT_RSA_SHA2_512;
 438         }
 439         return 0;
 440 }
 441
 442 /* ask agent to sign data, returns err.h code on error, 0 on success */
 443 int
 444 ssh_agent_sign(int sock, struct sshkey *key,
 445     u_char **sigp, size_t *lenp,
 446     const u_char *data, size_t datalen, const char *alg, u_int compat)
 447 {
 448         struct sshbuf *msg;
 449         u_char *blob = NULL, type;
 450         size_t blen = 0, len = 0;
 451         u_int flags = 0;
 452         int r = SSH_ERR_INTERNAL_ERROR;
 453
 454         *sigp = NULL;
 455         *lenp = 0;
 456
 457         if (datalen > SSH_KEY_MAX_SIGN_DATA_SIZE)
 458                 return SSH_ERR_INVALID_ARGUMENT;
 459         if (compat & SSH_BUG_SIGBLOB)
 460                 flags |= SSH_AGENT_OLD_SIGNATURE;
 461         if ((msg = sshbuf_new()) == NULL)
 462                 return SSH_ERR_ALLOC_FAIL;
 463         if ((r = sshkey_to_blob(key, &blob, &blen)) != 0)
 464                 goto out;
 465         flags |= agent_encode_alg(key, alg);
 466         if ((r = sshbuf_put_u8(msg, SSH2_AGENTC_SIGN_REQUEST)) != 0 ||
 467             (r = sshbuf_put_string(msg, blob, blen)) != 0 ||
 468             (r = sshbuf_put_string(msg, data, datalen)) != 0 ||
 469             (r = sshbuf_put_u32(msg, flags)) != 0)
 470                 goto out;
 471         if ((r = ssh_request_reply(sock, msg, msg)) != 0)
 472                 goto out;
 473         if ((r = sshbuf_get_u8(msg, &type)) != 0)
 474                 goto out;
 475         if (agent_failed(type)) {
 476                 r = SSH_ERR_AGENT_FAILURE;
 477                 goto out;
 478         } else if (type != SSH2_AGENT_SIGN_RESPONSE) {
 479                 r = SSH_ERR_INVALID_FORMAT;
 480                 goto out;
 481         }
 482         if ((r = sshbuf_get_string(msg, sigp, &len)) != 0)
 483                 goto out;
 484         *lenp = len;
 485         r = 0;
 486  out:
 487         if (blob != NULL) {
 488                 explicit_bzero(blob, blen);
 489                 free(blob);
 490         }
 491         sshbuf_free(msg);
 492         return r;
 493 }
 494
 495 /* Encode key for a message to the agent. */
 496
 497 #ifdef WITH_SSH1
 498 static int
 499 ssh_encode_identity_rsa1(struct sshbuf *b, RSA *key, const char *comment)
 500 {
 501         int r;
 502
 503         /* To keep within the protocol: p < q for ssh. in SSL p > q */
 504         if ((r = sshbuf_put_u32(b, BN_num_bits(key->n))) != 0 ||
 505             (r = sshbuf_put_bignum1(b, key->n)) != 0 ||
 506             (r = sshbuf_put_bignum1(b, key->e)) != 0 ||
 507             (r = sshbuf_put_bignum1(b, key->d)) != 0 ||
 508             (r = sshbuf_put_bignum1(b, key->iqmp)) != 0 ||
 509             (r = sshbuf_put_bignum1(b, key->q)) != 0 ||
 510             (r = sshbuf_put_bignum1(b, key->p)) != 0 ||
 511             (r = sshbuf_put_cstring(b, comment)) != 0)
 512                 return r;
 513         return 0;
 514 }
 515 #endif
 516
 517 static int
 518 ssh_encode_identity_ssh2(struct sshbuf *b, struct sshkey *key,
 519     const char *comment)
 520 {
 521         int r;
 522
 523         if ((r = sshkey_private_serialize(key, b)) != 0 ||
 524             (r = sshbuf_put_cstring(b, comment)) != 0)
 525                 return r;
 526         return 0;
 527 }
 528
 529 static int
 530 encode_constraints(struct sshbuf *m, u_int life, u_int confirm)
 531 {
 532         int r;
 533
 534         if (life != 0) {
 535                 if ((r = sshbuf_put_u8(m, SSH_AGENT_CONSTRAIN_LIFETIME)) != 0 ||
 536                     (r = sshbuf_put_u32(m, life)) != 0)
 537                         goto out;
 538         }
 539         if (confirm != 0) {
 540                 if ((r = sshbuf_put_u8(m, SSH_AGENT_CONSTRAIN_CONFIRM)) != 0)
 541                         goto out;
 542         }
 543         r = 0;
 544  out:
 545         return r;
 546 }
 547
 548 /*
 549  * Adds an identity to the authentication server.
 550  * This call is intended only for use by ssh-add(1) and like applications.
 551  */
 552 int
 553 ssh_add_identity_constrained(int sock, struct sshkey *key, const char *comment,
 554     u_int life, u_int confirm)
 555 {
 556         struct sshbuf *msg;
 557         int r, constrained = (life || confirm);
 558         u_char type;
 559
 560         if ((msg = sshbuf_new()) == NULL)
 561                 return SSH_ERR_ALLOC_FAIL;
 562
 563         switch (key->type) {
 564 #ifdef WITH_SSH1
 565         case KEY_RSA1:
 566                 type = constrained ?
 567                     SSH_AGENTC_ADD_RSA_ID_CONSTRAINED :
 568                     SSH_AGENTC_ADD_RSA_IDENTITY;
 569                 if ((r = sshbuf_put_u8(msg, type)) != 0 ||
 570                     (r = ssh_encode_identity_rsa1(msg, key->rsa, comment)) != 0)
 571                         goto out;
 572                 break;
 573 #endif
 574 #ifdef WITH_OPENSSL
 575         case KEY_RSA:
 576         case KEY_RSA_CERT:
 577         case KEY_DSA:
 578         case KEY_DSA_CERT:
 579         case KEY_ECDSA:
 580         case KEY_ECDSA_CERT:
 581 #endif
 582         case KEY_ED25519:
 583         case KEY_ED25519_CERT:
 584                 type = constrained ?
 585                     SSH2_AGENTC_ADD_ID_CONSTRAINED :
 586                     SSH2_AGENTC_ADD_IDENTITY;
 587                 if ((r = sshbuf_put_u8(msg, type)) != 0 ||
 588                     (r = ssh_encode_identity_ssh2(msg, key, comment)) != 0)
 589                         goto out;
 590                 break;
 591         default:
 592                 r = SSH_ERR_INVALID_ARGUMENT;
 593                 goto out;
 594         }
 595         if (constrained &&
 596             (r = encode_constraints(msg, life, confirm)) != 0)
 597                 goto out;
 598         if ((r = ssh_request_reply(sock, msg, msg)) != 0)
 599                 goto out;
 600         if ((r = sshbuf_get_u8(msg, &type)) != 0)
 601                 goto out;
 602         r = decode_reply(type);
 603  out:
 604         sshbuf_free(msg);
 605         return r;
 606 }
 607
 608 /*
 609  * Removes an identity from the authentication server.
 610  * This call is intended only for use by ssh-add(1) and like applications.
 611  */
 612 int
 613 ssh_remove_identity(int sock, struct sshkey *key)
 614 {
 615         struct sshbuf *msg;
 616         int r;
 617         u_char type, *blob = NULL;
 618         size_t blen;
 619
 620         if ((msg = sshbuf_new()) == NULL)
 621                 return SSH_ERR_ALLOC_FAIL;
 622
 623 #ifdef WITH_SSH1
 624         if (key->type == KEY_RSA1) {
 625                 if ((r = sshbuf_put_u8(msg,
 626                     SSH_AGENTC_REMOVE_RSA_IDENTITY)) != 0 ||
 627                     (r = sshbuf_put_u32(msg, BN_num_bits(key->rsa->n))) != 0 ||
 628                     (r = sshbuf_put_bignum1(msg, key->rsa->e)) != 0 ||
 629                     (r = sshbuf_put_bignum1(msg, key->rsa->n)) != 0)
 630                         goto out;
 631         } else
 632 #endif
 633         if (key->type != KEY_UNSPEC) {
 634                 if ((r = sshkey_to_blob(key, &blob, &blen)) != 0)
 635                         goto out;
 636                 if ((r = sshbuf_put_u8(msg,
 637                     SSH2_AGENTC_REMOVE_IDENTITY)) != 0 ||
 638                     (r = sshbuf_put_string(msg, blob, blen)) != 0)
 639                         goto out;
 640         } else {
 641                 r = SSH_ERR_INVALID_ARGUMENT;
 642                 goto out;
 643         }
 644         if ((r = ssh_request_reply(sock, msg, msg)) != 0)
 645                 goto out;
 646         if ((r = sshbuf_get_u8(msg, &type)) != 0)
 647                 goto out;
 648         r = decode_reply(type);
 649  out:
 650         if (blob != NULL) {
 651                 explicit_bzero(blob, blen);
 652                 free(blob);
 653         }
 654         sshbuf_free(msg);
 655         return r;
 656 }
 657
 658 /*
 659  * Add/remove an token-based identity from the authentication server.
 660  * This call is intended only for use by ssh-add(1) and like applications.
 661  */
 662 int
 663 ssh_update_card(int sock, int add, const char *reader_id, const char *pin,
 664     u_int life, u_int confirm)
 665 {
 666         struct sshbuf *msg;
 667         int r, constrained = (life || confirm);
 668         u_char type;
 669
 670         if (add) {
 671                 type = constrained ?
 672                     SSH_AGENTC_ADD_SMARTCARD_KEY_CONSTRAINED :
 673                     SSH_AGENTC_ADD_SMARTCARD_KEY;
 674         } else
 675                 type = SSH_AGENTC_REMOVE_SMARTCARD_KEY;
 676
 677         if ((msg = sshbuf_new()) == NULL)
 678                 return SSH_ERR_ALLOC_FAIL;
 679         if ((r = sshbuf_put_u8(msg, type)) != 0 ||
 680             (r = sshbuf_put_cstring(msg, reader_id)) != 0 ||
 681             (r = sshbuf_put_cstring(msg, pin)) != 0)
 682                 goto out;
 683         if (constrained &&
 684             (r = encode_constraints(msg, life, confirm)) != 0)
 685                 goto out;
 686         if ((r = ssh_request_reply(sock, msg, msg)) != 0)
 687                 goto out;
 688         if ((r = sshbuf_get_u8(msg, &type)) != 0)
 689                 goto out;
 690         r = decode_reply(type);
 691  out:
 692         sshbuf_free(msg);
 693         return r;
 694 }
 695
 696 /*
 697  * Removes all identities from the agent.
 698  * This call is intended only for use by ssh-add(1) and like applications.
 699  */
 700 int
 701 ssh_remove_all_identities(int sock, int version)
 702 {
 703         struct sshbuf *msg;
 704         u_char type = (version == 1) ?
 705             SSH_AGENTC_REMOVE_ALL_RSA_IDENTITIES :
 706             SSH2_AGENTC_REMOVE_ALL_IDENTITIES;
 707         int r;
 708
 709         if ((msg = sshbuf_new()) == NULL)
 710                 return SSH_ERR_ALLOC_FAIL;
 711         if ((r = sshbuf_put_u8(msg, type)) != 0)
 712                 goto out;
 713         if ((r = ssh_request_reply(sock, msg, msg)) != 0)
 714                 goto out;
 715         if ((r = sshbuf_get_u8(msg, &type)) != 0)
 716                 goto out;
 717         r = decode_reply(type);
 718  out:
 719         sshbuf_free(msg);
 720         return r;
 721 }