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 1.74 2001/08/01 23:33:09 markus Exp $");
  16
  17 #include <openssl/evp.h>
  18 #include <openssl/pem.h>
  19
  20 #ifdef SMARTCARD
  21 #include <sectok.h>
  22 #endif
  23
  24 #include "xmalloc.h"
  25 #include "key.h"
  26 #include "rsa.h"
  27 #include "authfile.h"
  28 #include "uuencode.h"
  29 #include "buffer.h"
  30 #include "bufaux.h"
  31 #include "pathnames.h"
  32 #include "log.h"
  33 #include "readpass.h"
  34
  35
  36 /* Number of bits in the RSA/DSA key.  This value can be changed on the command line. */
  37 int bits = 1024;
  38
  39 /*
  40  * Flag indicating that we just want to change the passphrase.  This can be
  41  * set on the command line.
  42  */
  43 int change_passphrase = 0;
  44
  45 /*
  46  * Flag indicating that we just want to change the comment.  This can be set
  47  * on the command line.
  48  */
  49 int change_comment = 0;
  50
  51 int quiet = 0;
  52
  53 /* Flag indicating that we just want to see the key fingerprint */
  54 int print_fingerprint = 0;
  55 int print_bubblebabble = 0;
  56
  57 /* The identity file name, given on the command line or entered by the user. */
  58 char identity_file[1024];
  59 int have_identity = 0;
  60
  61 /* This is set to the passphrase if given on the command line. */
  62 char *identity_passphrase = NULL;
  63
  64 /* This is set to the new passphrase if given on the command line. */
  65 char *identity_new_passphrase = NULL;
  66
  67 /* This is set to the new comment if given on the command line. */
  68 char *identity_comment = NULL;
  69
  70 /* Dump public key file in format used by real and the original SSH 2 */
  71 int convert_to_ssh2 = 0;
  72 int convert_from_ssh2 = 0;
  73 int print_public = 0;
  74
  75 /* default to RSA for SSH-1 */
  76 char *key_type_name = "rsa1";
  77
  78 /* argv0 */
  79 #ifdef HAVE___PROGNAME
  80 extern char *__progname;
  81 #else
  82 char *__progname;
  83 #endif
  84
  85 char hostname[MAXHOSTNAMELEN];
  86
  87 static void
  88 ask_filename(struct passwd *pw, const char *prompt)
  89 {
  90         char buf[1024];
  91         char *name = NULL;
  92
  93         switch (key_type_from_name(key_type_name)) {
  94         case KEY_RSA1:
  95                 name = _PATH_SSH_CLIENT_IDENTITY;
  96                 break;
  97         case KEY_DSA:
  98                 name = _PATH_SSH_CLIENT_ID_DSA;
  99                 break;
 100         case KEY_RSA:
 101                 name = _PATH_SSH_CLIENT_ID_RSA;
 102                 break;
 103         default:
 104                 fprintf(stderr, "bad key type");
 105                 exit(1);
 106                 break;
 107         }
 108         snprintf(identity_file, sizeof(identity_file), "%s/%s", pw->pw_dir, name);
 109         fprintf(stderr, "%s (%s): ", prompt, identity_file);
 110         fflush(stderr);
 111         if (fgets(buf, sizeof(buf), stdin) == NULL)
 112                 exit(1);
 113         if (strchr(buf, '\n'))
 114                 *strchr(buf, '\n') = 0;
 115         if (strcmp(buf, "") != 0)
 116                 strlcpy(identity_file, buf, sizeof(identity_file));
 117         have_identity = 1;
 118 }
 119
 120 static Key *
 121 load_identity(char *filename)
 122 {
 123         char *pass;
 124         Key *prv;
 125
 126         prv = key_load_private(filename, "", NULL);
 127         if (prv == NULL) {
 128                 if (identity_passphrase)
 129                         pass = xstrdup(identity_passphrase);
 130                 else
 131                         pass = read_passphrase("Enter passphrase: ",
 132                             RP_ALLOW_STDIN);
 133                 prv = key_load_private(filename, pass, NULL);
 134                 memset(pass, 0, strlen(pass));
 135                 xfree(pass);
 136         }
 137         return prv;
 138 }
 139
 140 #define SSH_COM_PUBLIC_BEGIN            "---- BEGIN SSH2 PUBLIC KEY ----"
 141 #define SSH_COM_PUBLIC_END              "---- END SSH2 PUBLIC KEY ----"
 142 #define SSH_COM_PRIVATE_BEGIN           "---- BEGIN SSH2 ENCRYPTED PRIVATE KEY ----"
 143 #define SSH_COM_PRIVATE_KEY_MAGIC       0x3f6ff9eb
 144
 145 static void
 146 do_convert_to_ssh2(struct passwd *pw)
 147 {
 148         Key *k;
 149         int len;
 150         u_char *blob;
 151         struct stat st;
 152
 153         if (!have_identity)
 154                 ask_filename(pw, "Enter file in which the key is");
 155         if (stat(identity_file, &st) < 0) {
 156                 perror(identity_file);
 157                 exit(1);
 158         }
 159         if ((k = key_load_public(identity_file, NULL)) == NULL) {
 160                 if ((k = load_identity(identity_file)) == NULL) {
 161                         fprintf(stderr, "load failed\n");
 162                         exit(1);
 163                 }
 164         }
 165         key_to_blob(k, &blob, &len);
 166         fprintf(stdout, "%s\n", SSH_COM_PUBLIC_BEGIN);
 167         fprintf(stdout,
 168             "Comment: \"%d-bit %s, converted from OpenSSH by %s@%s\"\n",
 169             key_size(k), key_type(k),
 170             pw->pw_name, hostname);
 171         dump_base64(stdout, blob, len);
 172         fprintf(stdout, "%s\n", SSH_COM_PUBLIC_END);
 173         key_free(k);
 174         xfree(blob);
 175         exit(0);
 176 }
 177
 178 static void
 179 buffer_get_bignum_bits(Buffer *b, BIGNUM *value)
 180 {
 181         int bits = buffer_get_int(b);
 182         int bytes = (bits + 7) / 8;
 183
 184         if (buffer_len(b) < bytes)
 185                 fatal("buffer_get_bignum_bits: input buffer too small: "
 186                     "need %d have %d", bytes, buffer_len(b));
 187         BN_bin2bn((u_char *)buffer_ptr(b), bytes, value);
 188         buffer_consume(b, bytes);
 189 }
 190
 191 static Key *
 192 do_convert_private_ssh2_from_blob(char *blob, int blen)
 193 {
 194         Buffer b;
 195         Key *key = NULL;
 196         char *type, *cipher;
 197         u_char *sig, data[] = "abcde12345";
 198         int magic, rlen, ktype, i1, i2, i3, i4;
 199         u_int slen;
 200         u_long e;
 201
 202         buffer_init(&b);
 203         buffer_append(&b, blob, blen);
 204
 205         magic  = buffer_get_int(&b);
 206         if (magic != SSH_COM_PRIVATE_KEY_MAGIC) {
 207                 error("bad magic 0x%x != 0x%x", magic, SSH_COM_PRIVATE_KEY_MAGIC);
 208                 buffer_free(&b);
 209                 return NULL;
 210         }
 211         i1 = buffer_get_int(&b);
 212         type   = buffer_get_string(&b, NULL);
 213         cipher = buffer_get_string(&b, NULL);
 214         i2 = buffer_get_int(&b);
 215         i3 = buffer_get_int(&b);
 216         i4 = buffer_get_int(&b);
 217         debug("ignore (%d %d %d %d)", i1,i2,i3,i4);
 218         if (strcmp(cipher, "none") != 0) {
 219                 error("unsupported cipher %s", cipher);
 220                 xfree(cipher);
 221                 buffer_free(&b);
 222                 xfree(type);
 223                 return NULL;
 224         }
 225         xfree(cipher);
 226
 227         if (strstr(type, "dsa")) {
 228                 ktype = KEY_DSA;
 229         } else if (strstr(type, "rsa")) {
 230                 ktype = KEY_RSA;
 231         } else {
 232                 xfree(type);
 233                 return NULL;
 234         }
 235         key = key_new_private(ktype);
 236         xfree(type);
 237
 238         switch (key->type) {
 239         case KEY_DSA:
 240                 buffer_get_bignum_bits(&b, key->dsa->p);
 241                 buffer_get_bignum_bits(&b, key->dsa->g);
 242                 buffer_get_bignum_bits(&b, key->dsa->q);
 243                 buffer_get_bignum_bits(&b, key->dsa->pub_key);
 244                 buffer_get_bignum_bits(&b, key->dsa->priv_key);
 245                 break;
 246         case KEY_RSA:
 247                 e  = buffer_get_char(&b);
 248                 debug("e %lx", e);
 249                 if (e < 30) {
 250                         e <<= 8;
 251                         e += buffer_get_char(&b);
 252                         debug("e %lx", e);
 253                         e <<= 8;
 254                         e += buffer_get_char(&b);
 255                         debug("e %lx", e);
 256                 }
 257                 if (!BN_set_word(key->rsa->e, e)) {
 258                         buffer_free(&b);
 259                         key_free(key);
 260                         return NULL;
 261                 }
 262                 buffer_get_bignum_bits(&b, key->rsa->d);
 263                 buffer_get_bignum_bits(&b, key->rsa->n);
 264                 buffer_get_bignum_bits(&b, key->rsa->iqmp);
 265                 buffer_get_bignum_bits(&b, key->rsa->q);
 266                 buffer_get_bignum_bits(&b, key->rsa->p);
 267                 rsa_generate_additional_parameters(key->rsa);
 268                 break;
 269         }
 270         rlen = buffer_len(&b);
 271         if(rlen != 0)
 272                 error("do_convert_private_ssh2_from_blob: "
 273                     "remaining bytes in key blob %d", rlen);
 274         buffer_free(&b);
 275
 276         /* try the key */
 277         key_sign(key, &sig, &slen, data, sizeof(data));
 278         key_verify(key, sig, slen, data, sizeof(data));
 279         xfree(sig);
 280         return key;
 281 }
 282
 283 static void
 284 do_convert_from_ssh2(struct passwd *pw)
 285 {
 286         Key *k;
 287         int blen;
 288         char line[1024], *p;
 289         char blob[8096];
 290         char encoded[8096];
 291         struct stat st;
 292         int escaped = 0, private = 0, ok;
 293         FILE *fp;
 294
 295         if (!have_identity)
 296                 ask_filename(pw, "Enter file in which the key is");
 297         if (stat(identity_file, &st) < 0) {
 298                 perror(identity_file);
 299                 exit(1);
 300         }
 301         fp = fopen(identity_file, "r");
 302         if (fp == NULL) {
 303                 perror(identity_file);
 304                 exit(1);
 305         }
 306         encoded[0] = '\0';
 307         while (fgets(line, sizeof(line), fp)) {
 308                 if (!(p = strchr(line, '\n'))) {
 309                         fprintf(stderr, "input line too long.\n");
 310                         exit(1);
 311                 }
 312                 if (p > line && p[-1] == '\\')
 313                         escaped++;
 314                 if (strncmp(line, "----", 4) == 0 ||
 315                     strstr(line, ": ") != NULL) {
 316                         if (strstr(line, SSH_COM_PRIVATE_BEGIN) != NULL)
 317                                 private = 1;
 318                         if (strstr(line, " END ") != NULL) {
 319                                 break;
 320                         }
 321                         /* fprintf(stderr, "ignore: %s", line); */
 322                         continue;
 323                 }
 324                 if (escaped) {
 325                         escaped--;
 326                         /* fprintf(stderr, "escaped: %s", line); */
 327                         continue;
 328                 }
 329                 *p = '\0';
 330                 strlcat(encoded, line, sizeof(encoded));
 331         }
 332         blen = uudecode(encoded, (u_char *)blob, sizeof(blob));
 333         if (blen < 0) {
 334                 fprintf(stderr, "uudecode failed.\n");
 335                 exit(1);
 336         }
 337         k = private ?
 338             do_convert_private_ssh2_from_blob(blob, blen) :
 339             key_from_blob(blob, blen);
 340         if (k == NULL) {
 341                 fprintf(stderr, "decode blob failed.\n");
 342                 exit(1);
 343         }
 344         ok = private ?
 345             (k->type == KEY_DSA ?
 346                  PEM_write_DSAPrivateKey(stdout, k->dsa, NULL, NULL, 0, NULL, NULL) :
 347                  PEM_write_RSAPrivateKey(stdout, k->rsa, NULL, NULL, 0, NULL, NULL)) :
 348             key_write(k, stdout);
 349         if (!ok) {
 350                 fprintf(stderr, "key write failed");
 351                 exit(1);
 352         }
 353         key_free(k);
 354         fprintf(stdout, "\n");
 355         fclose(fp);
 356         exit(0);
 357 }
 358
 359 static void
 360 do_print_public(struct passwd *pw)
 361 {
 362         Key *prv;
 363         struct stat st;
 364
 365         if (!have_identity)
 366                 ask_filename(pw, "Enter file in which the key is");
 367         if (stat(identity_file, &st) < 0) {
 368                 perror(identity_file);
 369                 exit(1);
 370         }
 371         prv = load_identity(identity_file);
 372         if (prv == NULL) {
 373                 fprintf(stderr, "load failed\n");
 374                 exit(1);
 375         }
 376         if (!key_write(prv, stdout))
 377                 fprintf(stderr, "key_write failed");
 378         key_free(prv);
 379         fprintf(stdout, "\n");
 380         exit(0);
 381 }
 382
 383 #ifdef SMARTCARD
 384 #define NUM_RSA_KEY_ELEMENTS 5+1
 385 #define COPY_RSA_KEY(x, i) \
 386         do { \
 387                 len = BN_num_bytes(prv->rsa->x); \
 388                 elements[i] = xmalloc(len); \
 389                 debug("#bytes %d", len); \
 390                 if (BN_bn2bin(prv->rsa->x, elements[i]) < 0) \
 391                         goto done; \
 392         } while(0)
 393
 394 static int
 395 get_AUT0(char *aut0)
 396 {
 397         EVP_MD *evp_md = EVP_sha1();
 398         EVP_MD_CTX md;
 399         char *pass;
 400
 401         pass = read_passphrase("Enter passphrase for smartcard: ", RP_ALLOW_STDIN);
 402         if (pass == NULL)
 403                 return -1;
 404         EVP_DigestInit(&md, evp_md);
 405         EVP_DigestUpdate(&md, pass, strlen(pass));
 406         EVP_DigestFinal(&md, aut0, NULL);
 407         memset(pass, 0, strlen(pass));
 408         xfree(pass);
 409         return 0;
 410 }
 411
 412 static void
 413 do_upload(struct passwd *pw, int reader)
 414 {
 415         Key *prv = NULL;
 416         struct stat st;
 417         u_char *elements[NUM_RSA_KEY_ELEMENTS];
 418         u_char key_fid[2];
 419         u_char DEFAUT0[] = {0xad, 0x9f, 0x61, 0xfe, 0xfa, 0x20, 0xce, 0x63};
 420         u_char AUT0[EVP_MAX_MD_SIZE];
 421         int len, status = 1, i, fd = -1, ret;
 422         int sw = 0, cla = 0x00;
 423
 424         for (i = 0; i < NUM_RSA_KEY_ELEMENTS; i++)
 425                 elements[i] = NULL;
 426         if (!have_identity)
 427                 ask_filename(pw, "Enter file in which the key is");
 428         if (stat(identity_file, &st) < 0) {
 429                 perror(identity_file);
 430                 goto done;
 431         }
 432         prv = load_identity(identity_file);
 433         if (prv == NULL) {
 434                 error("load failed");
 435                 goto done;
 436         }
 437         COPY_RSA_KEY(q, 0);
 438         COPY_RSA_KEY(p, 1);
 439         COPY_RSA_KEY(iqmp, 2);
 440         COPY_RSA_KEY(dmq1, 3);
 441         COPY_RSA_KEY(dmp1, 4);
 442         COPY_RSA_KEY(n, 5);
 443         len = BN_num_bytes(prv->rsa->n);
 444         fd = sectok_open(reader, STONOWAIT, &sw);
 445         if (fd < 0) {
 446                 error("sectok_open failed: %s", sectok_get_sw(sw));
 447                 goto done;
 448         }
 449         ret = sectok_reset(fd, 0, NULL, &sw);
 450         if (ret <= 0) {
 451                 error("sectok_reset failed: %s", sectok_get_sw(sw));
 452                 goto done;
 453         }
 454         if ((cla = cyberflex_inq_class(fd)) < 0) {
 455                 error("cyberflex_inq_class failed");
 456                 goto done;
 457         }
 458         memcpy(AUT0, DEFAUT0, sizeof(DEFAUT0));
 459         if (cyberflex_verify_AUT0(fd, cla, AUT0, sizeof(DEFAUT0)) < 0) {
 460                 if (get_AUT0(AUT0) < 0 ||
 461                     cyberflex_verify_AUT0(fd, cla, AUT0, sizeof(DEFAUT0)) < 0) {
 462                         error("cyberflex_verify_AUT0 failed");
 463                         goto done;
 464                 }
 465         }
 466         key_fid[0] = 0x00;
 467         key_fid[1] = 0x12;
 468         if (cyberflex_load_rsa_priv(fd, cla, key_fid, 5, 8*len, elements,
 469             &sw) < 0) {
 470                 error("cyberflex_load_rsa_priv failed: %s", sectok_get_sw(sw));
 471                 goto done;
 472         }
 473         if (!sectok_swOK(sw))
 474                 goto done;
 475         log("cyberflex_load_rsa_priv done");
 476         key_fid[0] = 0x73;
 477         key_fid[1] = 0x68;
 478         if (cyberflex_load_rsa_pub(fd, cla, key_fid, len, elements[5],
 479             &sw) < 0) {
 480                 error("cyberflex_load_rsa_pub failed: %s", sectok_get_sw(sw));
 481                 goto done;
 482         }
 483         if (!sectok_swOK(sw))
 484                 goto done;
 485         log("cyberflex_load_rsa_pub done");
 486         status = 0;
 487         log("loading key done");
 488 done:
 489         if (prv)
 490                 key_free(prv);
 491         for (i = 0; i < NUM_RSA_KEY_ELEMENTS; i++)
 492                 if (elements[i])
 493                         xfree(elements[i]);
 494         if (fd != -1)
 495                 sectok_close(fd);
 496         exit(status);
 497 }
 498 #endif
 499
 500 static void
 501 do_fingerprint(struct passwd *pw)
 502 {
 503         FILE *f;
 504         Key *public;
 505         char *comment = NULL, *cp, *ep, line[16*1024], *fp;
 506         int i, skip = 0, num = 1, invalid = 1, rep, fptype;
 507         struct stat st;
 508
 509         fptype = print_bubblebabble ? SSH_FP_SHA1 : SSH_FP_MD5;
 510         rep =    print_bubblebabble ? SSH_FP_BUBBLEBABBLE : SSH_FP_HEX;
 511
 512         if (!have_identity)
 513                 ask_filename(pw, "Enter file in which the key is");
 514         if (stat(identity_file, &st) < 0) {
 515                 perror(identity_file);
 516                 exit(1);
 517         }
 518         public = key_load_public(identity_file, &comment);
 519         if (public != NULL) {
 520                 fp = key_fingerprint(public, fptype, rep);
 521                 printf("%d %s %s\n", key_size(public), fp, comment);
 522                 key_free(public);
 523                 xfree(comment);
 524                 xfree(fp);
 525                 exit(0);
 526         }
 527         if (comment)
 528                 xfree(comment);
 529
 530         f = fopen(identity_file, "r");
 531         if (f != NULL) {
 532                 while (fgets(line, sizeof(line), f)) {
 533                         i = strlen(line) - 1;
 534                         if (line[i] != '\n') {
 535                                 error("line %d too long: %.40s...", num, line);
 536                                 skip = 1;
 537                                 continue;
 538                         }
 539                         num++;
 540                         if (skip) {
 541                                 skip = 0;
 542                                 continue;
 543                         }
 544                         line[i] = '\0';
 545
 546                         /* Skip leading whitespace, empty and comment lines. */
 547                         for (cp = line; *cp == ' ' || *cp == '\t'; cp++)
 548                                 ;
 549                         if (!*cp || *cp == '\n' || *cp == '#')
 550                                 continue ;
 551                         i = strtol(cp, &ep, 10);
 552                         if (i == 0 || ep == NULL || (*ep != ' ' && *ep != '\t')) {
 553                                 int quoted = 0;
 554                                 comment = cp;
 555                                 for (; *cp && (quoted || (*cp != ' ' && *cp != '\t')); cp++) {
 556                                         if (*cp == '\\' && cp[1] == '"')
 557                                                 cp++;   /* Skip both */
 558                                         else if (*cp == '"')
 559                                                 quoted = !quoted;
 560                                 }
 561                                 if (!*cp)
 562                                         continue;
 563                                 *cp++ = '\0';
 564                         }
 565                         ep = cp;
 566                         public = key_new(KEY_RSA1);
 567                         if (key_read(public, &cp) != 1) {
 568                                 cp = ep;
 569                                 key_free(public);
 570                                 public = key_new(KEY_UNSPEC);
 571                                 if (key_read(public, &cp) != 1) {
 572                                         key_free(public);
 573                                         continue;
 574                                 }
 575                         }
 576                         comment = *cp ? cp : comment;
 577                         fp = key_fingerprint(public, fptype, rep);
 578                         printf("%d %s %s\n", key_size(public), fp,
 579                             comment ? comment : "no comment");
 580                         xfree(fp);
 581                         key_free(public);
 582                         invalid = 0;
 583                 }
 584                 fclose(f);
 585         }
 586         if (invalid) {
 587                 printf("%s is not a valid key file.\n", identity_file);
 588                 exit(1);
 589         }
 590         exit(0);
 591 }
 592
 593 /*
 594  * Perform changing a passphrase.  The argument is the passwd structure
 595  * for the current user.
 596  */
 597 static void
 598 do_change_passphrase(struct passwd *pw)
 599 {
 600         char *comment;
 601         char *old_passphrase, *passphrase1, *passphrase2;
 602         struct stat st;
 603         Key *private;
 604
 605         if (!have_identity)
 606                 ask_filename(pw, "Enter file in which the key is");
 607         if (stat(identity_file, &st) < 0) {
 608                 perror(identity_file);
 609                 exit(1);
 610         }
 611         /* Try to load the file with empty passphrase. */
 612         private = key_load_private(identity_file, "", &comment);
 613         if (private == NULL) {
 614                 if (identity_passphrase)
 615                         old_passphrase = xstrdup(identity_passphrase);
 616                 else
 617                         old_passphrase =
 618                             read_passphrase("Enter old passphrase: ",
 619                             RP_ALLOW_STDIN);
 620                 private = key_load_private(identity_file, old_passphrase,
 621                     &comment);
 622                 memset(old_passphrase, 0, strlen(old_passphrase));
 623                 xfree(old_passphrase);
 624                 if (private == NULL) {
 625                         printf("Bad passphrase.\n");
 626                         exit(1);
 627                 }
 628         }
 629         printf("Key has comment '%s'\n", comment);
 630
 631         /* Ask the new passphrase (twice). */
 632         if (identity_new_passphrase) {
 633                 passphrase1 = xstrdup(identity_new_passphrase);
 634                 passphrase2 = NULL;
 635         } else {
 636                 passphrase1 =
 637                         read_passphrase("Enter new passphrase (empty for no "
 638                             "passphrase): ", RP_ALLOW_STDIN);
 639                 passphrase2 = read_passphrase("Enter same passphrase again: ",
 640                      RP_ALLOW_STDIN);
 641
 642                 /* Verify that they are the same. */
 643                 if (strcmp(passphrase1, passphrase2) != 0) {
 644                         memset(passphrase1, 0, strlen(passphrase1));
 645                         memset(passphrase2, 0, strlen(passphrase2));
 646                         xfree(passphrase1);
 647                         xfree(passphrase2);
 648                         printf("Pass phrases do not match.  Try again.\n");
 649                         exit(1);
 650                 }
 651                 /* Destroy the other copy. */
 652                 memset(passphrase2, 0, strlen(passphrase2));
 653                 xfree(passphrase2);
 654         }
 655
 656         /* Save the file using the new passphrase. */
 657         if (!key_save_private(private, identity_file, passphrase1, comment)) {
 658                 printf("Saving the key failed: %s.\n", identity_file);
 659                 memset(passphrase1, 0, strlen(passphrase1));
 660                 xfree(passphrase1);
 661                 key_free(private);
 662                 xfree(comment);
 663                 exit(1);
 664         }
 665         /* Destroy the passphrase and the copy of the key in memory. */
 666         memset(passphrase1, 0, strlen(passphrase1));
 667         xfree(passphrase1);
 668         key_free(private);               /* Destroys contents */
 669         xfree(comment);
 670
 671         printf("Your identification has been saved with the new passphrase.\n");
 672         exit(0);
 673 }
 674
 675 /*
 676  * Change the comment of a private key file.
 677  */
 678 static void
 679 do_change_comment(struct passwd *pw)
 680 {
 681         char new_comment[1024], *comment, *passphrase;
 682         Key *private;
 683         Key *public;
 684         struct stat st;
 685         FILE *f;
 686         int fd;
 687
 688         if (!have_identity)
 689                 ask_filename(pw, "Enter file in which the key is");
 690         if (stat(identity_file, &st) < 0) {
 691                 perror(identity_file);
 692                 exit(1);
 693         }
 694         private = key_load_private(identity_file, "", &comment);
 695         if (private == NULL) {
 696                 if (identity_passphrase)
 697                         passphrase = xstrdup(identity_passphrase);
 698                 else if (identity_new_passphrase)
 699                         passphrase = xstrdup(identity_new_passphrase);
 700                 else
 701                         passphrase = read_passphrase("Enter passphrase: ",
 702                             RP_ALLOW_STDIN);
 703                 /* Try to load using the passphrase. */
 704                 private = key_load_private(identity_file, passphrase, &comment);
 705                 if (private == NULL) {
 706                         memset(passphrase, 0, strlen(passphrase));
 707                         xfree(passphrase);
 708                         printf("Bad passphrase.\n");
 709                         exit(1);
 710                 }
 711         } else {
 712                 passphrase = xstrdup("");
 713         }
 714         if (private->type != KEY_RSA1) {
 715                 fprintf(stderr, "Comments are only supported for RSA1 keys.\n");
 716                 key_free(private);
 717                 exit(1);
 718         }
 719         printf("Key now has comment '%s'\n", comment);
 720
 721         if (identity_comment) {
 722                 strlcpy(new_comment, identity_comment, sizeof(new_comment));
 723         } else {
 724                 printf("Enter new comment: ");
 725                 fflush(stdout);
 726                 if (!fgets(new_comment, sizeof(new_comment), stdin)) {
 727                         memset(passphrase, 0, strlen(passphrase));
 728                         key_free(private);
 729                         exit(1);
 730                 }
 731                 if (strchr(new_comment, '\n'))
 732                         *strchr(new_comment, '\n') = 0;
 733         }
 734
 735         /* Save the file using the new passphrase. */
 736         if (!key_save_private(private, identity_file, passphrase, new_comment)) {
 737                 printf("Saving the key failed: %s.\n", identity_file);
 738                 memset(passphrase, 0, strlen(passphrase));
 739                 xfree(passphrase);
 740                 key_free(private);
 741                 xfree(comment);
 742                 exit(1);
 743         }
 744         memset(passphrase, 0, strlen(passphrase));
 745         xfree(passphrase);
 746         public = key_from_private(private);
 747         key_free(private);
 748
 749         strlcat(identity_file, ".pub", sizeof(identity_file));
 750         fd = open(identity_file, O_WRONLY | O_CREAT | O_TRUNC, 0644);
 751         if (fd == -1) {
 752                 printf("Could not save your public key in %s\n", identity_file);
 753                 exit(1);
 754         }
 755         f = fdopen(fd, "w");
 756         if (f == NULL) {
 757                 printf("fdopen %s failed", identity_file);
 758                 exit(1);
 759         }
 760         if (!key_write(public, f))
 761                 fprintf(stderr, "write key failed");
 762         key_free(public);
 763         fprintf(f, " %s\n", new_comment);
 764         fclose(f);
 765
 766         xfree(comment);
 767
 768         printf("The comment in your key file has been changed.\n");
 769         exit(0);
 770 }
 771
 772 static void
 773 usage(void)
 774 {
 775         printf("Usage: %s [-ceilpqyB] [-t type] [-b bits] [-f file] [-C comment] "
 776             "[-N new-pass] [-P pass]\n", __progname);
 777         exit(1);
 778 }
 779
 780 /*
 781  * Main program for key management.
 782  */
 783 int
 784 main(int ac, char **av)
 785 {
 786         char dotsshdir[16 * 1024], comment[1024], *passphrase1, *passphrase2;
 787         Key *private, *public;
 788         struct passwd *pw;
 789         int opt, type, fd, reader = -1;
 790         struct stat st;
 791         FILE *f;
 792
 793         extern int optind;
 794         extern char *optarg;
 795
 796         __progname = get_progname(av[0]);
 797         init_rng();
 798         seed_rng();
 799
 800         SSLeay_add_all_algorithms();
 801
 802         /* we need this for the home * directory.  */
 803         pw = getpwuid(getuid());
 804         if (!pw) {
 805                 printf("You don't exist, go away!\n");
 806                 exit(1);
 807         }
 808         if (gethostname(hostname, sizeof(hostname)) < 0) {
 809                 perror("gethostname");
 810                 exit(1);
 811         }
 812
 813         while ((opt = getopt(ac, av, "deiqpclBRxXyb:f:t:u:P:N:C:")) != -1) {
 814                 switch (opt) {
 815                 case 'b':
 816                         bits = atoi(optarg);
 817                         if (bits < 512 || bits > 32768) {
 818                                 printf("Bits has bad value.\n");
 819                                 exit(1);
 820                         }
 821                         break;
 822                 case 'l':
 823                         print_fingerprint = 1;
 824                         break;
 825                 case 'B':
 826                         print_bubblebabble = 1;
 827                         break;
 828                 case 'p':
 829                         change_passphrase = 1;
 830                         break;
 831                 case 'c':
 832                         change_comment = 1;
 833                         break;
 834                 case 'f':
 835                         strlcpy(identity_file, optarg, sizeof(identity_file));
 836                         have_identity = 1;
 837                         break;
 838                 case 'P':
 839                         identity_passphrase = optarg;
 840                         break;
 841                 case 'N':
 842                         identity_new_passphrase = optarg;
 843                         break;
 844                 case 'C':
 845                         identity_comment = optarg;
 846                         break;
 847                 case 'q':
 848                         quiet = 1;
 849                         break;
 850                 case 'R':
 851                         /* unused */
 852                         exit(0);
 853                         break;
 854                 case 'e':
 855                 case 'x':
 856                         /* export key */
 857                         convert_to_ssh2 = 1;
 858                         break;
 859                 case 'i':
 860                 case 'X':
 861                         /* import key */
 862                         convert_from_ssh2 = 1;
 863                         break;
 864                 case 'y':
 865                         print_public = 1;
 866                         break;
 867                 case 'd':
 868                         key_type_name = "dsa";
 869                         break;
 870                 case 't':
 871                         key_type_name = optarg;
 872                         break;
 873                 case 'u':
 874                         reader = atoi(optarg); /*XXX*/
 875                         break;
 876                 case '?':
 877                 default:
 878                         usage();
 879                 }
 880         }
 881         if (optind < ac) {
 882                 printf("Too many arguments.\n");
 883                 usage();
 884         }
 885         if (change_passphrase && change_comment) {
 886                 printf("Can only have one of -p and -c.\n");
 887                 usage();
 888         }
 889         if (print_fingerprint || print_bubblebabble)
 890                 do_fingerprint(pw);
 891         if (change_passphrase)
 892                 do_change_passphrase(pw);
 893         if (change_comment)
 894                 do_change_comment(pw);
 895         if (convert_to_ssh2)
 896                 do_convert_to_ssh2(pw);
 897         if (convert_from_ssh2)
 898                 do_convert_from_ssh2(pw);
 899         if (print_public)
 900                 do_print_public(pw);
 901         if (reader != -1)
 902 #ifdef SMARTCARD
 903                 do_upload(pw, reader);
 904 #else
 905                 fatal("no support for smartcards.");
 906 #endif
 907
 908         arc4random_stir();
 909
 910         type = key_type_from_name(key_type_name);
 911         if (type == KEY_UNSPEC) {
 912                 fprintf(stderr, "unknown key type %s\n", key_type_name);
 913                 exit(1);
 914         }
 915         if (!quiet)
 916                 printf("Generating public/private %s key pair.\n", key_type_name);
 917         private = key_generate(type, bits);
 918         if (private == NULL) {
 919                 fprintf(stderr, "key_generate failed");
 920                 exit(1);
 921         }
 922         public  = key_from_private(private);
 923
 924         if (!have_identity)
 925                 ask_filename(pw, "Enter file in which to save the key");
 926
 927         /* Create ~/.ssh directory if it doesn\'t already exist. */
 928         snprintf(dotsshdir, sizeof dotsshdir, "%s/%s", pw->pw_dir, _PATH_SSH_USER_DIR);
 929         if (strstr(identity_file, dotsshdir) != NULL &&
 930             stat(dotsshdir, &st) < 0) {
 931                 if (mkdir(dotsshdir, 0700) < 0)
 932                         error("Could not create directory '%s'.", dotsshdir);
 933                 else if (!quiet)
 934                         printf("Created directory '%s'.\n", dotsshdir);
 935         }
 936         /* If the file already exists, ask the user to confirm. */
 937         if (stat(identity_file, &st) >= 0) {
 938                 char yesno[3];
 939                 printf("%s already exists.\n", identity_file);
 940                 printf("Overwrite (y/n)? ");
 941                 fflush(stdout);
 942                 if (fgets(yesno, sizeof(yesno), stdin) == NULL)
 943                         exit(1);
 944                 if (yesno[0] != 'y' && yesno[0] != 'Y')
 945                         exit(1);
 946         }
 947         /* Ask for a passphrase (twice). */
 948         if (identity_passphrase)
 949                 passphrase1 = xstrdup(identity_passphrase);
 950         else if (identity_new_passphrase)
 951                 passphrase1 = xstrdup(identity_new_passphrase);
 952         else {
 953 passphrase_again:
 954                 passphrase1 =
 955                         read_passphrase("Enter passphrase (empty for no "
 956                             "passphrase): ", RP_ALLOW_STDIN);
 957                 passphrase2 = read_passphrase("Enter same passphrase again: ",
 958                     RP_ALLOW_STDIN);
 959                 if (strcmp(passphrase1, passphrase2) != 0) {
 960                         /*
 961                          * The passphrases do not match.  Clear them and
 962                          * retry.
 963                          */
 964                         memset(passphrase1, 0, strlen(passphrase1));
 965                         memset(passphrase2, 0, strlen(passphrase2));
 966                         xfree(passphrase1);
 967                         xfree(passphrase2);
 968                         printf("Passphrases do not match.  Try again.\n");
 969                         goto passphrase_again;
 970                 }
 971                 /* Clear the other copy of the passphrase. */
 972                 memset(passphrase2, 0, strlen(passphrase2));
 973                 xfree(passphrase2);
 974         }
 975
 976         if (identity_comment) {
 977                 strlcpy(comment, identity_comment, sizeof(comment));
 978         } else {
 979                 /* Create default commend field for the passphrase. */
 980                 snprintf(comment, sizeof comment, "%s@%s", pw->pw_name, hostname);
 981         }
 982
 983         /* Save the key with the given passphrase and comment. */
 984         if (!key_save_private(private, identity_file, passphrase1, comment)) {
 985                 printf("Saving the key failed: %s.\n", identity_file);
 986                 memset(passphrase1, 0, strlen(passphrase1));
 987                 xfree(passphrase1);
 988                 exit(1);
 989         }
 990         /* Clear the passphrase. */
 991         memset(passphrase1, 0, strlen(passphrase1));
 992         xfree(passphrase1);
 993
 994         /* Clear the private key and the random number generator. */
 995         key_free(private);
 996         arc4random_stir();
 997
 998         if (!quiet)
 999                 printf("Your identification has been saved in %s.\n", identity_file);
1000
1001         strlcat(identity_file, ".pub", sizeof(identity_file));
1002         fd = open(identity_file, O_WRONLY | O_CREAT | O_TRUNC, 0644);
1003         if (fd == -1) {
1004                 printf("Could not save your public key in %s\n", identity_file);
1005                 exit(1);
1006         }
1007         f = fdopen(fd, "w");
1008         if (f == NULL) {
1009                 printf("fdopen %s failed", identity_file);
1010                 exit(1);
1011         }
1012         if (!key_write(public, f))
1013                 fprintf(stderr, "write key failed");
1014         fprintf(f, " %s\n", comment);
1015         fclose(f);
1016
1017         if (!quiet) {
1018                 char *fp = key_fingerprint(public, SSH_FP_MD5, SSH_FP_HEX);
1019                 printf("Your public key has been saved in %s.\n",
1020                     identity_file);
1021                 printf("The key fingerprint is:\n");
1022                 printf("%s %s\n", fp, comment);
1023                 xfree(fp);
1024         }
1025
1026         key_free(public);
1027         exit(0);
1028 }