ssh-keygen.c

   1 /*
   2  * Author: Tatu Ylonen <ylo@cs.hut.fi>
   3  * Copyright (c) 1994 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
   4  *                    All rights reserved
   5  * Identity and host key generation and maintenance.
   6  *
   7  * As far as I am concerned, the code I have written for this software
   8  * can be used freely for any purpose.  Any derived versions of this
   9  * software must be clearly marked as such, and if the derived work is
  10  * incompatible with the protocol description in the RFC file, it must be
  11  * called by a name other than "ssh" or "Secure Shell".
  12  */
  13
  14 #include "includes.h"
  15 RCSID("$OpenBSD: ssh-keygen.c,v 1.86 2001/12/19 07:18:56 deraadt Exp $");
  16
  17 #include <openssl/evp.h>
  18 #include <openssl/pem.h>
  19
  20 #include "xmalloc.h"
  21 #include "key.h"
  22 #include "rsa.h"
  23 #include "authfile.h"
  24 #include "uuencode.h"
  25 #include "buffer.h"
  26 #include "bufaux.h"
  27 #include "pathnames.h"
  28 #include "log.h"
  29 #include "readpass.h"
  30
  31 #ifdef SMARTCARD
  32 #include <sectok.h>
  33 #include <openssl/engine.h>
  34 #include "scard.h"
  35 #endif
  36
  37 /* Number of bits in the RSA/DSA key.  This value can be changed on the command line. */
  38 int bits = 1024;
  39
  40 /*
  41  * Flag indicating that we just want to change the passphrase.  This can be
  42  * set on the command line.
  43  */
  44 int change_passphrase = 0;
  45
  46 /*
  47  * Flag indicating that we just want to change the comment.  This can be set
  48  * on the command line.
  49  */
  50 int change_comment = 0;
  51
  52 int quiet = 0;
  53
  54 /* Flag indicating that we just want to see the key fingerprint */
  55 int print_fingerprint = 0;
  56 int print_bubblebabble = 0;
  57
  58 /* The identity file name, given on the command line or entered by the user. */
  59 char identity_file[1024];
  60 int have_identity = 0;
  61
  62 /* This is set to the passphrase if given on the command line. */
  63 char *identity_passphrase = NULL;
  64
  65 /* This is set to the new passphrase if given on the command line. */
  66 char *identity_new_passphrase = NULL;
  67
  68 /* This is set to the new comment if given on the command line. */
  69 char *identity_comment = NULL;
  70
  71 /* Dump public key file in format used by real and the original SSH 2 */
  72 int convert_to_ssh2 = 0;
  73 int convert_from_ssh2 = 0;
  74 int print_public = 0;
  75
  76 /* default to RSA for SSH-1 */
  77 char *key_type_name = "rsa1";
  78
  79 /* argv0 */
  80 #ifdef HAVE___PROGNAME
  81 extern char *__progname;
  82 #else
  83 char *__progname;
  84 #endif
  85
  86 char hostname[MAXHOSTNAMELEN];
  87
  88 static void
  89 ask_filename(struct passwd *pw, const char *prompt)
  90 {
  91         char buf[1024];
  92         char *name = NULL;
  93
  94         switch (key_type_from_name(key_type_name)) {
  95         case KEY_RSA1:
  96                 name = _PATH_SSH_CLIENT_IDENTITY;
  97                 break;
  98         case KEY_DSA:
  99                 name = _PATH_SSH_CLIENT_ID_DSA;
 100                 break;
 101         case KEY_RSA:
 102                 name = _PATH_SSH_CLIENT_ID_RSA;
 103                 break;
 104         default:
 105                 fprintf(stderr, "bad key type");
 106                 exit(1);
 107                 break;
 108         }
 109         snprintf(identity_file, sizeof(identity_file), "%s/%s", pw->pw_dir, name);
 110         fprintf(stderr, "%s (%s): ", prompt, identity_file);
 111         fflush(stderr);
 112         if (fgets(buf, sizeof(buf), stdin) == NULL)
 113                 exit(1);
 114         if (strchr(buf, '\n'))
 115                 *strchr(buf, '\n') = 0;
 116         if (strcmp(buf, "") != 0)
 117                 strlcpy(identity_file, buf, sizeof(identity_file));
 118         have_identity = 1;
 119 }
 120
 121 static Key *
 122 load_identity(char *filename)
 123 {
 124         char *pass;
 125         Key *prv;
 126
 127         prv = key_load_private(filename, "", NULL);
 128         if (prv == NULL) {
 129                 if (identity_passphrase)
 130                         pass = xstrdup(identity_passphrase);
 131                 else
 132                         pass = read_passphrase("Enter passphrase: ",
 133                             RP_ALLOW_STDIN);
 134                 prv = key_load_private(filename, pass, NULL);
 135                 memset(pass, 0, strlen(pass));
 136                 xfree(pass);
 137         }
 138         return prv;
 139 }
 140
 141 #define SSH_COM_PUBLIC_BEGIN            "---- BEGIN SSH2 PUBLIC KEY ----"
 142 #define SSH_COM_PUBLIC_END              "---- END SSH2 PUBLIC KEY ----"
 143 #define SSH_COM_PRIVATE_BEGIN           "---- BEGIN SSH2 ENCRYPTED PRIVATE KEY ----"
 144 #define SSH_COM_PRIVATE_KEY_MAGIC       0x3f6ff9eb
 145
 146 static void
 147 do_convert_to_ssh2(struct passwd *pw)
 148 {
 149         Key *k;
 150         int len;
 151         u_char *blob;
 152         struct stat st;
 153
 154         if (!have_identity)
 155                 ask_filename(pw, "Enter file in which the key is");
 156         if (stat(identity_file, &st) < 0) {
 157                 perror(identity_file);
 158                 exit(1);
 159         }
 160         if ((k = key_load_public(identity_file, NULL)) == NULL) {
 161                 if ((k = load_identity(identity_file)) == NULL) {
 162                         fprintf(stderr, "load failed\n");
 163                         exit(1);
 164                 }
 165         }
 166         if (key_to_blob(k, &blob, &len) <= 0) {
 167                 fprintf(stderr, "key_to_blob failed\n");
 168                 exit(1);
 169         }
 170         fprintf(stdout, "%s\n", SSH_COM_PUBLIC_BEGIN);
 171         fprintf(stdout,
 172             "Comment: \"%d-bit %s, converted from OpenSSH by %s@%s\"\n",
 173             key_size(k), key_type(k),
 174             pw->pw_name, hostname);
 175         dump_base64(stdout, blob, len);
 176         fprintf(stdout, "%s\n", SSH_COM_PUBLIC_END);
 177         key_free(k);
 178         xfree(blob);
 179         exit(0);
 180 }
 181
 182 static void
 183 buffer_get_bignum_bits(Buffer *b, BIGNUM *value)
 184 {
 185         int bits = buffer_get_int(b);
 186         int bytes = (bits + 7) / 8;
 187
 188         if (buffer_len(b) < bytes)
 189                 fatal("buffer_get_bignum_bits: input buffer too small: "
 190                     "need %d have %d", bytes, buffer_len(b));
 191         BN_bin2bn((u_char *)buffer_ptr(b), bytes, value);
 192         buffer_consume(b, bytes);
 193 }
 194
 195 static Key *
 196 do_convert_private_ssh2_from_blob(u_char *blob, int blen)
 197 {
 198         Buffer b;
 199         Key *key = NULL;
 200         char *type, *cipher;
 201         u_char *sig, data[] = "abcde12345";
 202         int magic, rlen, ktype, i1, i2, i3, i4;
 203         u_int slen;
 204         u_long e;
 205
 206         buffer_init(&b);
 207         buffer_append(&b, blob, blen);
 208
 209         magic  = buffer_get_int(&b);
 210         if (magic != SSH_COM_PRIVATE_KEY_MAGIC) {
 211                 error("bad magic 0x%x != 0x%x", magic, SSH_COM_PRIVATE_KEY_MAGIC);
 212                 buffer_free(&b);
 213                 return NULL;
 214         }
 215         i1 = buffer_get_int(&b);
 216         type   = buffer_get_string(&b, NULL);
 217         cipher = buffer_get_string(&b, NULL);
 218         i2 = buffer_get_int(&b);
 219         i3 = buffer_get_int(&b);
 220         i4 = buffer_get_int(&b);
 221         debug("ignore (%d %d %d %d)", i1,i2,i3,i4);
 222         if (strcmp(cipher, "none") != 0) {
 223                 error("unsupported cipher %s", cipher);
 224                 xfree(cipher);
 225                 buffer_free(&b);
 226                 xfree(type);
 227                 return NULL;
 228         }
 229         xfree(cipher);
 230
 231         if (strstr(type, "dsa")) {
 232                 ktype = KEY_DSA;
 233         } else if (strstr(type, "rsa")) {
 234                 ktype = KEY_RSA;
 235         } else {
 236                 xfree(type);
 237                 return NULL;
 238         }
 239         key = key_new_private(ktype);
 240         xfree(type);
 241
 242         switch (key->type) {
 243         case KEY_DSA:
 244                 buffer_get_bignum_bits(&b, key->dsa->p);
 245                 buffer_get_bignum_bits(&b, key->dsa->g);
 246                 buffer_get_bignum_bits(&b, key->dsa->q);
 247                 buffer_get_bignum_bits(&b, key->dsa->pub_key);
 248                 buffer_get_bignum_bits(&b, key->dsa->priv_key);
 249                 break;
 250         case KEY_RSA:
 251                 e  = buffer_get_char(&b);
 252                 debug("e %lx", e);
 253                 if (e < 30) {
 254                         e <<= 8;
 255                         e += buffer_get_char(&b);
 256                         debug("e %lx", e);
 257                         e <<= 8;
 258                         e += buffer_get_char(&b);
 259                         debug("e %lx", e);
 260                 }
 261                 if (!BN_set_word(key->rsa->e, e)) {
 262                         buffer_free(&b);
 263                         key_free(key);
 264                         return NULL;
 265                 }
 266                 buffer_get_bignum_bits(&b, key->rsa->d);
 267                 buffer_get_bignum_bits(&b, key->rsa->n);
 268                 buffer_get_bignum_bits(&b, key->rsa->iqmp);
 269                 buffer_get_bignum_bits(&b, key->rsa->q);
 270                 buffer_get_bignum_bits(&b, key->rsa->p);
 271                 rsa_generate_additional_parameters(key->rsa);
 272                 break;
 273         }
 274         rlen = buffer_len(&b);
 275         if (rlen != 0)
 276                 error("do_convert_private_ssh2_from_blob: "
 277                     "remaining bytes in key blob %d", rlen);
 278         buffer_free(&b);
 279
 280         /* try the key */
 281         key_sign(key, &sig, &slen, data, sizeof(data));
 282         key_verify(key, sig, slen, data, sizeof(data));
 283         xfree(sig);
 284         return key;
 285 }
 286
 287 static void
 288 do_convert_from_ssh2(struct passwd *pw)
 289 {
 290         Key *k;
 291         int blen;
 292         char line[1024], *p;
 293         u_char blob[8096];
 294         char encoded[8096];
 295         struct stat st;
 296         int escaped = 0, private = 0, ok;
 297         FILE *fp;
 298
 299         if (!have_identity)
 300                 ask_filename(pw, "Enter file in which the key is");
 301         if (stat(identity_file, &st) < 0) {
 302                 perror(identity_file);
 303                 exit(1);
 304         }
 305         fp = fopen(identity_file, "r");
 306         if (fp == NULL) {
 307                 perror(identity_file);
 308                 exit(1);
 309         }
 310         encoded[0] = '\0';
 311         while (fgets(line, sizeof(line), fp)) {
 312                 if (!(p = strchr(line, '\n'))) {
 313                         fprintf(stderr, "input line too long.\n");
 314                         exit(1);
 315                 }
 316                 if (p > line && p[-1] == '\\')
 317                         escaped++;
 318                 if (strncmp(line, "----", 4) == 0 ||
 319                     strstr(line, ": ") != NULL) {
 320                         if (strstr(line, SSH_COM_PRIVATE_BEGIN) != NULL)
 321                                 private = 1;
 322                         if (strstr(line, " END ") != NULL) {
 323                                 break;
 324                         }
 325                         /* fprintf(stderr, "ignore: %s", line); */
 326                         continue;
 327                 }
 328                 if (escaped) {
 329                         escaped--;
 330                         /* fprintf(stderr, "escaped: %s", line); */
 331                         continue;
 332                 }
 333                 *p = '\0';
 334                 strlcat(encoded, line, sizeof(encoded));
 335         }
 336         blen = uudecode(encoded, (u_char *)blob, sizeof(blob));
 337         if (blen < 0) {
 338                 fprintf(stderr, "uudecode failed.\n");
 339                 exit(1);
 340         }
 341         k = private ?
 342             do_convert_private_ssh2_from_blob(blob, blen) :
 343             key_from_blob(blob, blen);
 344         if (k == NULL) {
 345                 fprintf(stderr, "decode blob failed.\n");
 346                 exit(1);
 347         }
 348         ok = private ?
 349             (k->type == KEY_DSA ?
 350                  PEM_write_DSAPrivateKey(stdout, k->dsa, NULL, NULL, 0, NULL, NULL) :
 351                  PEM_write_RSAPrivateKey(stdout, k->rsa, NULL, NULL, 0, NULL, NULL)) :
 352             key_write(k, stdout);
 353         if (!ok) {
 354                 fprintf(stderr, "key write failed");
 355                 exit(1);
 356         }
 357         key_free(k);
 358         fprintf(stdout, "\n");
 359         fclose(fp);
 360         exit(0);
 361 }
 362
 363 static void
 364 do_print_public(struct passwd *pw)
 365 {
 366         Key *prv;
 367         struct stat st;
 368
 369         if (!have_identity)
 370                 ask_filename(pw, "Enter file in which the key is");
 371         if (stat(identity_file, &st) < 0) {
 372                 perror(identity_file);
 373                 exit(1);
 374         }
 375         prv = load_identity(identity_file);
 376         if (prv == NULL) {
 377                 fprintf(stderr, "load failed\n");
 378                 exit(1);
 379         }
 380         if (!key_write(prv, stdout))
 381                 fprintf(stderr, "key_write failed");
 382         key_free(prv);
 383         fprintf(stdout, "\n");
 384         exit(0);
 385 }
 386
 387 #ifdef SMARTCARD
 388 #define NUM_RSA_KEY_ELEMENTS 5+1
 389 #define COPY_RSA_KEY(x, i) \
 390         do { \
 391                 len = BN_num_bytes(prv->rsa->x); \
 392                 elements[i] = xmalloc(len); \
 393                 debug("#bytes %d", len); \
 394                 if (BN_bn2bin(prv->rsa->x, elements[i]) < 0) \
 395                         goto done; \
 396         } while (0)
 397
 398 static int
 399 get_AUT0(char *aut0)
 400 {
 401         EVP_MD *evp_md = EVP_sha1();
 402         EVP_MD_CTX md;
 403         char *pass;
 404
 405         pass = read_passphrase("Enter passphrase for smartcard: ", RP_ALLOW_STDIN);
 406         if (pass == NULL)
 407                 return -1;
 408         EVP_DigestInit(&md, evp_md);
 409         EVP_DigestUpdate(&md, pass, strlen(pass));
 410         EVP_DigestFinal(&md, aut0, NULL);
 411         memset(pass, 0, strlen(pass));
 412         xfree(pass);
 413         return 0;
 414 }
 415
 416 static void
 417 do_upload(struct passwd *pw, const char *sc_reader_id)
 418 {
 419         Key *prv = NULL;
 420         struct stat st;
 421         u_char *elements[NUM_RSA_KEY_ELEMENTS];
 422         u_char key_fid[2];
 423         u_char DEFAUT0[] = {0xad, 0x9f, 0x61, 0xfe, 0xfa, 0x20, 0xce, 0x63};
 424         u_char AUT0[EVP_MAX_MD_SIZE];
 425         int len, status = 1, i, fd = -1, ret;
 426         int sw = 0, cla = 0x00;
 427
 428         for (i = 0; i < NUM_RSA_KEY_ELEMENTS; i++)
 429                 elements[i] = NULL;
 430         if (!have_identity)
 431                 ask_filename(pw, "Enter file in which the key is");
 432         if (stat(identity_file, &st) < 0) {
 433                 perror(identity_file);
 434                 goto done;
 435         }
 436         prv = load_identity(identity_file);
 437         if (prv == NULL) {
 438                 error("load failed");
 439                 goto done;
 440         }
 441         COPY_RSA_KEY(q, 0);
 442         COPY_RSA_KEY(p, 1);
 443         COPY_RSA_KEY(iqmp, 2);
 444         COPY_RSA_KEY(dmq1, 3);
 445         COPY_RSA_KEY(dmp1, 4);
 446         COPY_RSA_KEY(n, 5);
 447         len = BN_num_bytes(prv->rsa->n);
 448         fd = sectok_friendly_open(sc_reader_id, STONOWAIT, &sw);
 449         if (fd < 0) {
 450                 error("sectok_open failed: %s", sectok_get_sw(sw));
 451                 goto done;
 452         }
 453         if (! sectok_cardpresent(fd)) {
 454                 error("smartcard in reader %s not present",
 455                     sc_reader_id);
 456                 goto done;
 457         }
 458         ret = sectok_reset(fd, 0, NULL, &sw);
 459         if (ret <= 0) {
 460                 error("sectok_reset failed: %s", sectok_get_sw(sw));
 461                 goto done;
 462         }
 463         if ((cla = cyberflex_inq_class(fd)) < 0) {
 464                 error("cyberflex_inq_class failed");
 465                 goto done;
 466         }
 467         memcpy(AUT0, DEFAUT0, sizeof(DEFAUT0));
 468         if (cyberflex_verify_AUT0(fd, cla, AUT0, sizeof(DEFAUT0)) < 0) {
 469                 if (get_AUT0(AUT0) < 0 ||
 470                     cyberflex_verify_AUT0(fd, cla, AUT0, sizeof(DEFAUT0)) < 0) {
 471                         error("cyberflex_verify_AUT0 failed");
 472                         goto done;
 473                 }
 474         }
 475         key_fid[0] = 0x00;
 476         key_fid[1] = 0x12;
 477         if (cyberflex_load_rsa_priv(fd, cla, key_fid, 5, 8*len, elements,
 478             &sw) < 0) {
 479                 error("cyberflex_load_rsa_priv failed: %s", sectok_get_sw(sw));
 480                 goto done;
 481         }
 482         if (!sectok_swOK(sw))
 483                 goto done;
 484         log("cyberflex_load_rsa_priv done");
 485         key_fid[0] = 0x73;
 486         key_fid[1] = 0x68;
 487         if (cyberflex_load_rsa_pub(fd, cla, key_fid, len, elements[5],
 488             &sw) < 0) {
 489                 error("cyberflex_load_rsa_pub failed: %s", sectok_get_sw(sw));
 490                 goto done;
 491         }
 492         if (!sectok_swOK(sw))
 493                 goto done;
 494         log("cyberflex_load_rsa_pub done");
 495         status = 0;
 496         log("loading key done");
 497 done:
 498
 499         memset(elements[0], '\0', BN_num_bytes(prv->rsa->q));
 500         memset(elements[1], '\0', BN_num_bytes(prv->rsa->p));
 501         memset(elements[2], '\0', BN_num_bytes(prv->rsa->iqmp));
 502         memset(elements[3], '\0', BN_num_bytes(prv->rsa->dmq1));
 503         memset(elements[4], '\0', BN_num_bytes(prv->rsa->dmp1));
 504         memset(elements[5], '\0', BN_num_bytes(prv->rsa->n));
 505
 506         if (prv)
 507                 key_free(prv);
 508         for (i = 0; i < NUM_RSA_KEY_ELEMENTS; i++)
 509                 if (elements[i])
 510                         xfree(elements[i]);
 511         if (fd != -1)
 512                 sectok_close(fd);
 513         exit(status);
 514 }
 515
 516 static void
 517 do_download(struct passwd *pw, const char *sc_reader_id)
 518 {
 519         Key *pub = NULL;
 520
 521         pub = sc_get_key(sc_reader_id);
 522         if (pub == NULL)
 523                 fatal("cannot read public key from smartcard");
 524         key_write(pub, stdout);
 525         key_free(pub);
 526         fprintf(stdout, "\n");
 527         exit(0);
 528 }
 529 #endif /* SMARTCARD */
 530
 531 static void
 532 do_fingerprint(struct passwd *pw)
 533 {
 534         FILE *f;
 535         Key *public;
 536         char *comment = NULL, *cp, *ep, line[16*1024], *fp;
 537         int i, skip = 0, num = 1, invalid = 1;
 538         enum fp_rep rep;
 539         enum fp_type fptype;
 540         struct stat st;
 541
 542         fptype = print_bubblebabble ? SSH_FP_SHA1 : SSH_FP_MD5;
 543         rep =    print_bubblebabble ? SSH_FP_BUBBLEBABBLE : SSH_FP_HEX;
 544
 545         if (!have_identity)
 546                 ask_filename(pw, "Enter file in which the key is");
 547         if (stat(identity_file, &st) < 0) {
 548                 perror(identity_file);
 549                 exit(1);
 550         }
 551         public = key_load_public(identity_file, &comment);
 552         if (public != NULL) {
 553                 fp = key_fingerprint(public, fptype, rep);
 554                 printf("%d %s %s\n", key_size(public), fp, comment);
 555                 key_free(public);
 556                 xfree(comment);
 557                 xfree(fp);
 558                 exit(0);
 559         }
 560         if (comment)
 561                 xfree(comment);
 562
 563         f = fopen(identity_file, "r");
 564         if (f != NULL) {
 565                 while (fgets(line, sizeof(line), f)) {
 566                         i = strlen(line) - 1;
 567                         if (line[i] != '\n') {
 568                                 error("line %d too long: %.40s...", num, line);
 569                                 skip = 1;
 570                                 continue;
 571                         }
 572                         num++;
 573                         if (skip) {
 574                                 skip = 0;
 575                                 continue;
 576                         }
 577                         line[i] = '\0';
 578
 579                         /* Skip leading whitespace, empty and comment lines. */
 580                         for (cp = line; *cp == ' ' || *cp == '\t'; cp++)
 581                                 ;
 582                         if (!*cp || *cp == '\n' || *cp == '#')
 583                                 continue ;
 584                         i = strtol(cp, &ep, 10);
 585                         if (i == 0 || ep == NULL || (*ep != ' ' && *ep != '\t')) {
 586                                 int quoted = 0;
 587                                 comment = cp;
 588                                 for (; *cp && (quoted || (*cp != ' ' && *cp != '\t')); cp++) {
 589                                         if (*cp == '\\' && cp[1] == '"')
 590                                                 cp++;   /* Skip both */
 591                                         else if (*cp == '"')
 592                                                 quoted = !quoted;
 593                                 }
 594                                 if (!*cp)
 595                                         continue;
 596                                 *cp++ = '\0';
 597                         }
 598                         ep = cp;
 599                         public = key_new(KEY_RSA1);
 600                         if (key_read(public, &cp) != 1) {
 601                                 cp = ep;
 602                                 key_free(public);
 603                                 public = key_new(KEY_UNSPEC);
 604                                 if (key_read(public, &cp) != 1) {
 605                                         key_free(public);
 606                                         continue;
 607                                 }
 608                         }
 609                         comment = *cp ? cp : comment;
 610                         fp = key_fingerprint(public, fptype, rep);
 611                         printf("%d %s %s\n", key_size(public), fp,
 612                             comment ? comment : "no comment");
 613                         xfree(fp);
 614                         key_free(public);
 615                         invalid = 0;
 616                 }
 617                 fclose(f);
 618         }
 619         if (invalid) {
 620                 printf("%s is not a public key file.\n", identity_file);
 621                 exit(1);
 622         }
 623         exit(0);
 624 }
 625
 626 /*
 627  * Perform changing a passphrase.  The argument is the passwd structure
 628  * for the current user.
 629  */
 630 static void
 631 do_change_passphrase(struct passwd *pw)
 632 {
 633         char *comment;
 634         char *old_passphrase, *passphrase1, *passphrase2;
 635         struct stat st;
 636         Key *private;
 637
 638         if (!have_identity)
 639                 ask_filename(pw, "Enter file in which the key is");
 640         if (stat(identity_file, &st) < 0) {
 641                 perror(identity_file);
 642                 exit(1);
 643         }
 644         /* Try to load the file with empty passphrase. */
 645         private = key_load_private(identity_file, "", &comment);
 646         if (private == NULL) {
 647                 if (identity_passphrase)
 648                         old_passphrase = xstrdup(identity_passphrase);
 649                 else
 650                         old_passphrase =
 651                             read_passphrase("Enter old passphrase: ",
 652                             RP_ALLOW_STDIN);
 653                 private = key_load_private(identity_file, old_passphrase,
 654                     &comment);
 655                 memset(old_passphrase, 0, strlen(old_passphrase));
 656                 xfree(old_passphrase);
 657                 if (private == NULL) {
 658                         printf("Bad passphrase.\n");
 659                         exit(1);
 660                 }
 661         }
 662         printf("Key has comment '%s'\n", comment);
 663
 664         /* Ask the new passphrase (twice). */
 665         if (identity_new_passphrase) {
 666                 passphrase1 = xstrdup(identity_new_passphrase);
 667                 passphrase2 = NULL;
 668         } else {
 669                 passphrase1 =
 670                         read_passphrase("Enter new passphrase (empty for no "
 671                             "passphrase): ", RP_ALLOW_STDIN);
 672                 passphrase2 = read_passphrase("Enter same passphrase again: ",
 673                     RP_ALLOW_STDIN);
 674
 675                 /* Verify that they are the same. */
 676                 if (strcmp(passphrase1, passphrase2) != 0) {
 677                         memset(passphrase1, 0, strlen(passphrase1));
 678                         memset(passphrase2, 0, strlen(passphrase2));
 679                         xfree(passphrase1);
 680                         xfree(passphrase2);
 681                         printf("Pass phrases do not match.  Try again.\n");
 682                         exit(1);
 683                 }
 684                 /* Destroy the other copy. */
 685                 memset(passphrase2, 0, strlen(passphrase2));
 686                 xfree(passphrase2);
 687         }
 688
 689         /* Save the file using the new passphrase. */
 690         if (!key_save_private(private, identity_file, passphrase1, comment)) {
 691                 printf("Saving the key failed: %s.\n", identity_file);
 692                 memset(passphrase1, 0, strlen(passphrase1));
 693                 xfree(passphrase1);
 694                 key_free(private);
 695                 xfree(comment);
 696                 exit(1);
 697         }
 698         /* Destroy the passphrase and the copy of the key in memory. */
 699         memset(passphrase1, 0, strlen(passphrase1));
 700         xfree(passphrase1);
 701         key_free(private);               /* Destroys contents */
 702         xfree(comment);
 703
 704         printf("Your identification has been saved with the new passphrase.\n");
 705         exit(0);
 706 }
 707
 708 /*
 709  * Change the comment of a private key file.
 710  */
 711 static void
 712 do_change_comment(struct passwd *pw)
 713 {
 714         char new_comment[1024], *comment, *passphrase;
 715         Key *private;
 716         Key *public;
 717         struct stat st;
 718         FILE *f;
 719         int fd;
 720
 721         if (!have_identity)
 722                 ask_filename(pw, "Enter file in which the key is");
 723         if (stat(identity_file, &st) < 0) {
 724                 perror(identity_file);
 725                 exit(1);
 726         }
 727         private = key_load_private(identity_file, "", &comment);
 728         if (private == NULL) {
 729                 if (identity_passphrase)
 730                         passphrase = xstrdup(identity_passphrase);
 731                 else if (identity_new_passphrase)
 732                         passphrase = xstrdup(identity_new_passphrase);
 733                 else
 734                         passphrase = read_passphrase("Enter passphrase: ",
 735                             RP_ALLOW_STDIN);
 736                 /* Try to load using the passphrase. */
 737                 private = key_load_private(identity_file, passphrase, &comment);
 738                 if (private == NULL) {
 739                         memset(passphrase, 0, strlen(passphrase));
 740                         xfree(passphrase);
 741                         printf("Bad passphrase.\n");
 742                         exit(1);
 743                 }
 744         } else {
 745                 passphrase = xstrdup("");
 746         }
 747         if (private->type != KEY_RSA1) {
 748                 fprintf(stderr, "Comments are only supported for RSA1 keys.\n");
 749                 key_free(private);
 750                 exit(1);
 751         }
 752         printf("Key now has comment '%s'\n", comment);
 753
 754         if (identity_comment) {
 755                 strlcpy(new_comment, identity_comment, sizeof(new_comment));
 756         } else {
 757                 printf("Enter new comment: ");
 758                 fflush(stdout);
 759                 if (!fgets(new_comment, sizeof(new_comment), stdin)) {
 760                         memset(passphrase, 0, strlen(passphrase));
 761                         key_free(private);
 762                         exit(1);
 763                 }
 764                 if (strchr(new_comment, '\n'))
 765                         *strchr(new_comment, '\n') = 0;
 766         }
 767
 768         /* Save the file using the new passphrase. */
 769         if (!key_save_private(private, identity_file, passphrase, new_comment)) {
 770                 printf("Saving the key failed: %s.\n", identity_file);
 771                 memset(passphrase, 0, strlen(passphrase));
 772                 xfree(passphrase);
 773                 key_free(private);
 774                 xfree(comment);
 775                 exit(1);
 776         }
 777         memset(passphrase, 0, strlen(passphrase));
 778         xfree(passphrase);
 779         public = key_from_private(private);
 780         key_free(private);
 781
 782         strlcat(identity_file, ".pub", sizeof(identity_file));
 783         fd = open(identity_file, O_WRONLY | O_CREAT | O_TRUNC, 0644);
 784         if (fd == -1) {
 785                 printf("Could not save your public key in %s\n", identity_file);
 786                 exit(1);
 787         }
 788         f = fdopen(fd, "w");
 789         if (f == NULL) {
 790                 printf("fdopen %s failed", identity_file);
 791                 exit(1);
 792         }
 793         if (!key_write(public, f))
 794                 fprintf(stderr, "write key failed");
 795         key_free(public);
 796         fprintf(f, " %s\n", new_comment);
 797         fclose(f);
 798
 799         xfree(comment);
 800
 801         printf("The comment in your key file has been changed.\n");
 802         exit(0);
 803 }
 804
 805 static void
 806 usage(void)
 807 {
 808         fprintf(stderr, "Usage: %s [options]\n", __progname);
 809         fprintf(stderr, "Options:\n");
 810         fprintf(stderr, "  -b bits     Number of bits in the key to create.\n");
 811         fprintf(stderr, "  -c          Change comment in private and public key files.\n");
 812         fprintf(stderr, "  -e          Convert OpenSSH to IETF SECSH key file.\n");
 813         fprintf(stderr, "  -f filename Filename of the key file.\n");
 814         fprintf(stderr, "  -i          Convert IETF SECSH to OpenSSH key file.\n");
 815         fprintf(stderr, "  -l          Show fingerprint of key file.\n");
 816         fprintf(stderr, "  -p          Change passphrase of private key file.\n");
 817         fprintf(stderr, "  -q          Quiet.\n");
 818         fprintf(stderr, "  -y          Read private key file and print public key.\n");
 819         fprintf(stderr, "  -t type     Specify type of key to create.\n");
 820         fprintf(stderr, "  -B          Show bubblebabble digest of key file.\n");
 821         fprintf(stderr, "  -C comment  Provide new comment.\n");
 822         fprintf(stderr, "  -N phrase   Provide new passphrase.\n");
 823         fprintf(stderr, "  -P phrase   Provide old passphrase.\n");
 824 #ifdef SMARTCARD
 825         fprintf(stderr, "  -D reader   Download public key from smartcard.\n");
 826         fprintf(stderr, "  -U reader   Upload private key to smartcard.\n");
 827 #endif /* SMARTCARD */
 828
 829         exit(1);
 830 }
 831
 832 /*
 833  * Main program for key management.
 834  */
 835 int
 836 main(int ac, char **av)
 837 {
 838         char dotsshdir[16 * 1024], comment[1024], *passphrase1, *passphrase2;
 839         char *reader_id = NULL;
 840         Key *private, *public;
 841         struct passwd *pw;
 842         struct stat st;
 843         int opt, type, fd, download = 0;
 844         FILE *f;
 845
 846         extern int optind;
 847         extern char *optarg;
 848
 849         __progname = get_progname(av[0]);
 850         init_rng();
 851         seed_rng();
 852
 853         SSLeay_add_all_algorithms();
 854
 855         /* we need this for the home * directory.  */
 856         pw = getpwuid(getuid());
 857         if (!pw) {
 858                 printf("You don't exist, go away!\n");
 859                 exit(1);
 860         }
 861         if (gethostname(hostname, sizeof(hostname)) < 0) {
 862                 perror("gethostname");
 863                 exit(1);
 864         }
 865
 866         while ((opt = getopt(ac, av, "deiqpclBRxXyb:f:t:U:D:P:N:C:")) != -1) {
 867                 switch (opt) {
 868                 case 'b':
 869                         bits = atoi(optarg);
 870                         if (bits < 512 || bits > 32768) {
 871                                 printf("Bits has bad value.\n");
 872                                 exit(1);
 873                         }
 874                         break;
 875                 case 'l':
 876                         print_fingerprint = 1;
 877                         break;
 878                 case 'B':
 879                         print_bubblebabble = 1;
 880                         break;
 881                 case 'p':
 882                         change_passphrase = 1;
 883                         break;
 884                 case 'c':
 885                         change_comment = 1;
 886                         break;
 887                 case 'f':
 888                         strlcpy(identity_file, optarg, sizeof(identity_file));
 889                         have_identity = 1;
 890                         break;
 891                 case 'P':
 892                         identity_passphrase = optarg;
 893                         break;
 894                 case 'N':
 895                         identity_new_passphrase = optarg;
 896                         break;
 897                 case 'C':
 898                         identity_comment = optarg;
 899                         break;
 900                 case 'q':
 901                         quiet = 1;
 902                         break;
 903                 case 'R':
 904                         /* unused */
 905                         exit(0);
 906                         break;
 907                 case 'e':
 908                 case 'x':
 909                         /* export key */
 910                         convert_to_ssh2 = 1;
 911                         break;
 912                 case 'i':
 913                 case 'X':
 914                         /* import key */
 915                         convert_from_ssh2 = 1;
 916                         break;
 917                 case 'y':
 918                         print_public = 1;
 919                         break;
 920                 case 'd':
 921                         key_type_name = "dsa";
 922                         break;
 923                 case 't':
 924                         key_type_name = optarg;
 925                         break;
 926                 case 'D':
 927                         download = 1;
 928                 case 'U':
 929                         reader_id = optarg;
 930                         break;
 931                 case '?':
 932                 default:
 933                         usage();
 934                 }
 935         }
 936         if (optind < ac) {
 937                 printf("Too many arguments.\n");
 938                 usage();
 939         }
 940         if (change_passphrase && change_comment) {
 941                 printf("Can only have one of -p and -c.\n");
 942                 usage();
 943         }
 944         if (print_fingerprint || print_bubblebabble)
 945                 do_fingerprint(pw);
 946         if (change_passphrase)
 947                 do_change_passphrase(pw);
 948         if (change_comment)
 949                 do_change_comment(pw);
 950         if (convert_to_ssh2)
 951                 do_convert_to_ssh2(pw);
 952         if (convert_from_ssh2)
 953                 do_convert_from_ssh2(pw);
 954         if (print_public)
 955                 do_print_public(pw);
 956         if (reader_id != NULL) {
 957 #ifdef SMARTCARD
 958                 if (download)
 959                         do_download(pw, reader_id);
 960                 else
 961                         do_upload(pw, reader_id);
 962 #else /* SMARTCARD */
 963                 fatal("no support for smartcards.");
 964 #endif /* SMARTCARD */
 965         }
 966
 967         arc4random_stir();
 968
 969         type = key_type_from_name(key_type_name);
 970         if (type == KEY_UNSPEC) {
 971                 fprintf(stderr, "unknown key type %s\n", key_type_name);
 972                 exit(1);
 973         }
 974         if (!quiet)
 975                 printf("Generating public/private %s key pair.\n", key_type_name);
 976         private = key_generate(type, bits);
 977         if (private == NULL) {
 978                 fprintf(stderr, "key_generate failed");
 979                 exit(1);
 980         }
 981         public  = key_from_private(private);
 982
 983         if (!have_identity)
 984                 ask_filename(pw, "Enter file in which to save the key");
 985
 986         /* Create ~/.ssh directory if it doesn\'t already exist. */
 987         snprintf(dotsshdir, sizeof dotsshdir, "%s/%s", pw->pw_dir, _PATH_SSH_USER_DIR);
 988         if (strstr(identity_file, dotsshdir) != NULL &&
 989             stat(dotsshdir, &st) < 0) {
 990                 if (mkdir(dotsshdir, 0700) < 0)
 991                         error("Could not create directory '%s'.", dotsshdir);
 992                 else if (!quiet)
 993                         printf("Created directory '%s'.\n", dotsshdir);
 994         }
 995         /* If the file already exists, ask the user to confirm. */
 996         if (stat(identity_file, &st) >= 0) {
 997                 char yesno[3];
 998                 printf("%s already exists.\n", identity_file);
 999                 printf("Overwrite (y/n)? ");
1000                 fflush(stdout);
1001                 if (fgets(yesno, sizeof(yesno), stdin) == NULL)
1002                         exit(1);
1003                 if (yesno[0] != 'y' && yesno[0] != 'Y')
1004                         exit(1);
1005         }
1006         /* Ask for a passphrase (twice). */
1007         if (identity_passphrase)
1008                 passphrase1 = xstrdup(identity_passphrase);
1009         else if (identity_new_passphrase)
1010                 passphrase1 = xstrdup(identity_new_passphrase);
1011         else {
1012 passphrase_again:
1013                 passphrase1 =
1014                         read_passphrase("Enter passphrase (empty for no "
1015                             "passphrase): ", RP_ALLOW_STDIN);
1016                 passphrase2 = read_passphrase("Enter same passphrase again: ",
1017                     RP_ALLOW_STDIN);
1018                 if (strcmp(passphrase1, passphrase2) != 0) {
1019                         /*
1020                          * The passphrases do not match.  Clear them and
1021                          * retry.
1022                          */
1023                         memset(passphrase1, 0, strlen(passphrase1));
1024                         memset(passphrase2, 0, strlen(passphrase2));
1025                         xfree(passphrase1);
1026                         xfree(passphrase2);
1027                         printf("Passphrases do not match.  Try again.\n");
1028                         goto passphrase_again;
1029                 }
1030                 /* Clear the other copy of the passphrase. */
1031                 memset(passphrase2, 0, strlen(passphrase2));
1032                 xfree(passphrase2);
1033         }
1034
1035         if (identity_comment) {
1036                 strlcpy(comment, identity_comment, sizeof(comment));
1037         } else {
1038                 /* Create default commend field for the passphrase. */
1039                 snprintf(comment, sizeof comment, "%s@%s", pw->pw_name, hostname);
1040         }
1041
1042         /* Save the key with the given passphrase and comment. */
1043         if (!key_save_private(private, identity_file, passphrase1, comment)) {
1044                 printf("Saving the key failed: %s.\n", identity_file);
1045                 memset(passphrase1, 0, strlen(passphrase1));
1046                 xfree(passphrase1);
1047                 exit(1);
1048         }
1049         /* Clear the passphrase. */
1050         memset(passphrase1, 0, strlen(passphrase1));
1051         xfree(passphrase1);
1052
1053         /* Clear the private key and the random number generator. */
1054         key_free(private);
1055         arc4random_stir();
1056
1057         if (!quiet)
1058                 printf("Your identification has been saved in %s.\n", identity_file);
1059
1060         strlcat(identity_file, ".pub", sizeof(identity_file));
1061         fd = open(identity_file, O_WRONLY | O_CREAT | O_TRUNC, 0644);
1062         if (fd == -1) {
1063                 printf("Could not save your public key in %s\n", identity_file);
1064                 exit(1);
1065         }
1066         f = fdopen(fd, "w");
1067         if (f == NULL) {
1068                 printf("fdopen %s failed", identity_file);
1069                 exit(1);
1070         }
1071         if (!key_write(public, f))
1072                 fprintf(stderr, "write key failed");
1073         fprintf(f, " %s\n", comment);
1074         fclose(f);
1075
1076         if (!quiet) {
1077                 char *fp = key_fingerprint(public, SSH_FP_MD5, SSH_FP_HEX);
1078                 printf("Your public key has been saved in %s.\n",
1079                     identity_file);
1080                 printf("The key fingerprint is:\n");
1081                 printf("%s %s\n", fp, comment);
1082                 xfree(fp);
1083         }
1084
1085         key_free(public);
1086         exit(0);
1087 }