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 1.73 2001/07/26 20:04:27 rees 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 #define NUM_RSA_KEY_ELEMENTS 5+1
 384 #define COPY_RSA_KEY(x, i) \
 385         do { \
 386                 len = BN_num_bytes(prv->rsa->x); \
 387                 elements[i] = xmalloc(len); \
 388                 debug("#bytes %d", len); \
 389                 if (BN_bn2bin(prv->rsa->x, elements[i]) < 0) \
 390                         goto done; \
 391         } while(0)
 392
 393 static void
 394 do_upload(struct passwd *pw, int reader)
 395 {
 396 #ifndef SMARTCARD
 397         fatal("no support for smartcards.");
 398 #else
 399         Key *prv = NULL;
 400         struct stat st;
 401         u_char *elements[NUM_RSA_KEY_ELEMENTS];
 402         u_char key_fid[2];
 403         u_char AUT0[] = {0xad, 0x9f, 0x61, 0xfe, 0xfa, 0x20, 0xce, 0x63};
 404         int len, status = 1, i, fd = -1, ret;
 405         int sw = 0, cla = 0x00;
 406
 407         for (i = 0; i < NUM_RSA_KEY_ELEMENTS; i++)
 408                 elements[i] = NULL;
 409         if (!have_identity)
 410                 ask_filename(pw, "Enter file in which the key is");
 411         if (stat(identity_file, &st) < 0) {
 412                 perror(identity_file);
 413                 goto done;
 414         }
 415         prv = load_identity(identity_file);
 416         if (prv == NULL) {
 417                 error("load failed");
 418                 goto done;
 419         }
 420         COPY_RSA_KEY(q, 0);
 421         COPY_RSA_KEY(p, 1);
 422         COPY_RSA_KEY(iqmp, 2);
 423         COPY_RSA_KEY(dmq1, 3);
 424         COPY_RSA_KEY(dmp1, 4);
 425         COPY_RSA_KEY(n, 5);
 426         len = BN_num_bytes(prv->rsa->n);
 427         fd = sectok_open(reader, 0, &sw);
 428         if (fd < 0) {
 429                 error("sectok_open failed");
 430                 goto done;
 431         }
 432         ret = sectok_reset(fd, 0, NULL, &sw);
 433         if (ret <= 0) {
 434                 error("sectok_reset failed");
 435                 goto done;
 436         }
 437         if ((cla = cyberflex_inq_class(fd)) < 0) {
 438                 error("cyberflex_inq_class failed");
 439                 goto done;
 440         }
 441         if (cyberflex_verify_AUT0(fd, cla, AUT0, sizeof(AUT0)) < 0) {
 442                 error("cyberflex_verify_AUT0 failed");
 443                 goto done;
 444         }
 445         key_fid[0] = 0x00;
 446         key_fid[1] = 0x12;
 447         if (cyberflex_load_rsa_priv(fd, cla, key_fid, 5, 8*len, elements,
 448             &sw) < 0) {
 449                 error("cyberflex_load_rsa_priv failed: %s", sectok_get_sw(sw));
 450                 goto done;
 451         }
 452         if (!sectok_swOK(sw))
 453                 goto done;
 454         log("cyberflex_load_rsa_priv done");
 455         key_fid[0] = 0x73;
 456         key_fid[1] = 0x68;
 457         if (cyberflex_load_rsa_pub(fd, cla, key_fid, len, elements[5],
 458             &sw) < 0) {
 459                 error("cyberflex_load_rsa_pub failed: %s", sectok_get_sw(sw));
 460                 goto done;
 461         }
 462         if (!sectok_swOK(sw))
 463                 goto done;
 464         log("cyberflex_load_rsa_pub done");
 465         status = 0;
 466         log("loading key done");
 467 done:
 468         if (prv)
 469                 key_free(prv);
 470         for (i = 0; i < NUM_RSA_KEY_ELEMENTS; i++)
 471                 if (elements[i])
 472                         xfree(elements[i]);
 473         if (fd != -1)
 474                 sectok_close(fd);
 475         exit(status);
 476 #endif
 477 }
 478
 479 static void
 480 do_fingerprint(struct passwd *pw)
 481 {
 482         FILE *f;
 483         Key *public;
 484         char *comment = NULL, *cp, *ep, line[16*1024], *fp;
 485         int i, skip = 0, num = 1, invalid = 1, rep, fptype;
 486         struct stat st;
 487
 488         fptype = print_bubblebabble ? SSH_FP_SHA1 : SSH_FP_MD5;
 489         rep =    print_bubblebabble ? SSH_FP_BUBBLEBABBLE : SSH_FP_HEX;
 490
 491         if (!have_identity)
 492                 ask_filename(pw, "Enter file in which the key is");
 493         if (stat(identity_file, &st) < 0) {
 494                 perror(identity_file);
 495                 exit(1);
 496         }
 497         public = key_load_public(identity_file, &comment);
 498         if (public != NULL) {
 499                 fp = key_fingerprint(public, fptype, rep);
 500                 printf("%d %s %s\n", key_size(public), fp, comment);
 501                 key_free(public);
 502                 xfree(comment);
 503                 xfree(fp);
 504                 exit(0);
 505         }
 506         if (comment)
 507                 xfree(comment);
 508
 509         f = fopen(identity_file, "r");
 510         if (f != NULL) {
 511                 while (fgets(line, sizeof(line), f)) {
 512                         i = strlen(line) - 1;
 513                         if (line[i] != '\n') {
 514                                 error("line %d too long: %.40s...", num, line);
 515                                 skip = 1;
 516                                 continue;
 517                         }
 518                         num++;
 519                         if (skip) {
 520                                 skip = 0;
 521                                 continue;
 522                         }
 523                         line[i] = '\0';
 524
 525                         /* Skip leading whitespace, empty and comment lines. */
 526                         for (cp = line; *cp == ' ' || *cp == '\t'; cp++)
 527                                 ;
 528                         if (!*cp || *cp == '\n' || *cp == '#')
 529                                 continue ;
 530                         i = strtol(cp, &ep, 10);
 531                         if (i == 0 || ep == NULL || (*ep != ' ' && *ep != '\t')) {
 532                                 int quoted = 0;
 533                                 comment = cp;
 534                                 for (; *cp && (quoted || (*cp != ' ' && *cp != '\t')); cp++) {
 535                                         if (*cp == '\\' && cp[1] == '"')
 536                                                 cp++;   /* Skip both */
 537                                         else if (*cp == '"')
 538                                                 quoted = !quoted;
 539                                 }
 540                                 if (!*cp)
 541                                         continue;
 542                                 *cp++ = '\0';
 543                         }
 544                         ep = cp;
 545                         public = key_new(KEY_RSA1);
 546                         if (key_read(public, &cp) != 1) {
 547                                 cp = ep;
 548                                 key_free(public);
 549                                 public = key_new(KEY_UNSPEC);
 550                                 if (key_read(public, &cp) != 1) {
 551                                         key_free(public);
 552                                         continue;
 553                                 }
 554                         }
 555                         comment = *cp ? cp : comment;
 556                         fp = key_fingerprint(public, fptype, rep);
 557                         printf("%d %s %s\n", key_size(public), fp,
 558                             comment ? comment : "no comment");
 559                         xfree(fp);
 560                         key_free(public);
 561                         invalid = 0;
 562                 }
 563                 fclose(f);
 564         }
 565         if (invalid) {
 566                 printf("%s is not a valid key file.\n", identity_file);
 567                 exit(1);
 568         }
 569         exit(0);
 570 }
 571
 572 /*
 573  * Perform changing a passphrase.  The argument is the passwd structure
 574  * for the current user.
 575  */
 576 static void
 577 do_change_passphrase(struct passwd *pw)
 578 {
 579         char *comment;
 580         char *old_passphrase, *passphrase1, *passphrase2;
 581         struct stat st;
 582         Key *private;
 583
 584         if (!have_identity)
 585                 ask_filename(pw, "Enter file in which the key is");
 586         if (stat(identity_file, &st) < 0) {
 587                 perror(identity_file);
 588                 exit(1);
 589         }
 590         /* Try to load the file with empty passphrase. */
 591         private = key_load_private(identity_file, "", &comment);
 592         if (private == NULL) {
 593                 if (identity_passphrase)
 594                         old_passphrase = xstrdup(identity_passphrase);
 595                 else
 596                         old_passphrase =
 597                             read_passphrase("Enter old passphrase: ",
 598                             RP_ALLOW_STDIN);
 599                 private = key_load_private(identity_file, old_passphrase,
 600                     &comment);
 601                 memset(old_passphrase, 0, strlen(old_passphrase));
 602                 xfree(old_passphrase);
 603                 if (private == NULL) {
 604                         printf("Bad passphrase.\n");
 605                         exit(1);
 606                 }
 607         }
 608         printf("Key has comment '%s'\n", comment);
 609
 610         /* Ask the new passphrase (twice). */
 611         if (identity_new_passphrase) {
 612                 passphrase1 = xstrdup(identity_new_passphrase);
 613                 passphrase2 = NULL;
 614         } else {
 615                 passphrase1 =
 616                         read_passphrase("Enter new passphrase (empty for no "
 617                             "passphrase): ", RP_ALLOW_STDIN);
 618                 passphrase2 = read_passphrase("Enter same passphrase again: ",
 619                      RP_ALLOW_STDIN);
 620
 621                 /* Verify that they are the same. */
 622                 if (strcmp(passphrase1, passphrase2) != 0) {
 623                         memset(passphrase1, 0, strlen(passphrase1));
 624                         memset(passphrase2, 0, strlen(passphrase2));
 625                         xfree(passphrase1);
 626                         xfree(passphrase2);
 627                         printf("Pass phrases do not match.  Try again.\n");
 628                         exit(1);
 629                 }
 630                 /* Destroy the other copy. */
 631                 memset(passphrase2, 0, strlen(passphrase2));
 632                 xfree(passphrase2);
 633         }
 634
 635         /* Save the file using the new passphrase. */
 636         if (!key_save_private(private, identity_file, passphrase1, comment)) {
 637                 printf("Saving the key failed: %s.\n", identity_file);
 638                 memset(passphrase1, 0, strlen(passphrase1));
 639                 xfree(passphrase1);
 640                 key_free(private);
 641                 xfree(comment);
 642                 exit(1);
 643         }
 644         /* Destroy the passphrase and the copy of the key in memory. */
 645         memset(passphrase1, 0, strlen(passphrase1));
 646         xfree(passphrase1);
 647         key_free(private);               /* Destroys contents */
 648         xfree(comment);
 649
 650         printf("Your identification has been saved with the new passphrase.\n");
 651         exit(0);
 652 }
 653
 654 /*
 655  * Change the comment of a private key file.
 656  */
 657 static void
 658 do_change_comment(struct passwd *pw)
 659 {
 660         char new_comment[1024], *comment, *passphrase;
 661         Key *private;
 662         Key *public;
 663         struct stat st;
 664         FILE *f;
 665         int fd;
 666
 667         if (!have_identity)
 668                 ask_filename(pw, "Enter file in which the key is");
 669         if (stat(identity_file, &st) < 0) {
 670                 perror(identity_file);
 671                 exit(1);
 672         }
 673         private = key_load_private(identity_file, "", &comment);
 674         if (private == NULL) {
 675                 if (identity_passphrase)
 676                         passphrase = xstrdup(identity_passphrase);
 677                 else if (identity_new_passphrase)
 678                         passphrase = xstrdup(identity_new_passphrase);
 679                 else
 680                         passphrase = read_passphrase("Enter passphrase: ",
 681                             RP_ALLOW_STDIN);
 682                 /* Try to load using the passphrase. */
 683                 private = key_load_private(identity_file, passphrase, &comment);
 684                 if (private == NULL) {
 685                         memset(passphrase, 0, strlen(passphrase));
 686                         xfree(passphrase);
 687                         printf("Bad passphrase.\n");
 688                         exit(1);
 689                 }
 690         } else {
 691                 passphrase = xstrdup("");
 692         }
 693         if (private->type != KEY_RSA1) {
 694                 fprintf(stderr, "Comments are only supported for RSA1 keys.\n");
 695                 key_free(private);
 696                 exit(1);
 697         }
 698         printf("Key now has comment '%s'\n", comment);
 699
 700         if (identity_comment) {
 701                 strlcpy(new_comment, identity_comment, sizeof(new_comment));
 702         } else {
 703                 printf("Enter new comment: ");
 704                 fflush(stdout);
 705                 if (!fgets(new_comment, sizeof(new_comment), stdin)) {
 706                         memset(passphrase, 0, strlen(passphrase));
 707                         key_free(private);
 708                         exit(1);
 709                 }
 710                 if (strchr(new_comment, '\n'))
 711                         *strchr(new_comment, '\n') = 0;
 712         }
 713
 714         /* Save the file using the new passphrase. */
 715         if (!key_save_private(private, identity_file, passphrase, new_comment)) {
 716                 printf("Saving the key failed: %s.\n", identity_file);
 717                 memset(passphrase, 0, strlen(passphrase));
 718                 xfree(passphrase);
 719                 key_free(private);
 720                 xfree(comment);
 721                 exit(1);
 722         }
 723         memset(passphrase, 0, strlen(passphrase));
 724         xfree(passphrase);
 725         public = key_from_private(private);
 726         key_free(private);
 727
 728         strlcat(identity_file, ".pub", sizeof(identity_file));
 729         fd = open(identity_file, O_WRONLY | O_CREAT | O_TRUNC, 0644);
 730         if (fd == -1) {
 731                 printf("Could not save your public key in %s\n", identity_file);
 732                 exit(1);
 733         }
 734         f = fdopen(fd, "w");
 735         if (f == NULL) {
 736                 printf("fdopen %s failed", identity_file);
 737                 exit(1);
 738         }
 739         if (!key_write(public, f))
 740                 fprintf(stderr, "write key failed");
 741         key_free(public);
 742         fprintf(f, " %s\n", new_comment);
 743         fclose(f);
 744
 745         xfree(comment);
 746
 747         printf("The comment in your key file has been changed.\n");
 748         exit(0);
 749 }
 750
 751 static void
 752 usage(void)
 753 {
 754         printf("Usage: %s [-ceilpqyB] [-t type] [-b bits] [-f file] [-C comment] "
 755             "[-N new-pass] [-P pass]\n", __progname);
 756         exit(1);
 757 }
 758
 759 /*
 760  * Main program for key management.
 761  */
 762 int
 763 main(int ac, char **av)
 764 {
 765         char dotsshdir[16 * 1024], comment[1024], *passphrase1, *passphrase2;
 766         Key *private, *public;
 767         struct passwd *pw;
 768         int opt, type, fd, reader = -1;
 769         struct stat st;
 770         FILE *f;
 771
 772         extern int optind;
 773         extern char *optarg;
 774
 775         __progname = get_progname(av[0]);
 776         init_rng();
 777         seed_rng();
 778
 779         SSLeay_add_all_algorithms();
 780
 781         /* we need this for the home * directory.  */
 782         pw = getpwuid(getuid());
 783         if (!pw) {
 784                 printf("You don't exist, go away!\n");
 785                 exit(1);
 786         }
 787         if (gethostname(hostname, sizeof(hostname)) < 0) {
 788                 perror("gethostname");
 789                 exit(1);
 790         }
 791
 792         while ((opt = getopt(ac, av, "deiqpclBRxXyb:f:t:u:P:N:C:")) != -1) {
 793                 switch (opt) {
 794                 case 'b':
 795                         bits = atoi(optarg);
 796                         if (bits < 512 || bits > 32768) {
 797                                 printf("Bits has bad value.\n");
 798                                 exit(1);
 799                         }
 800                         break;
 801                 case 'l':
 802                         print_fingerprint = 1;
 803                         break;
 804                 case 'B':
 805                         print_bubblebabble = 1;
 806                         break;
 807                 case 'p':
 808                         change_passphrase = 1;
 809                         break;
 810                 case 'c':
 811                         change_comment = 1;
 812                         break;
 813                 case 'f':
 814                         strlcpy(identity_file, optarg, sizeof(identity_file));
 815                         have_identity = 1;
 816                         break;
 817                 case 'P':
 818                         identity_passphrase = optarg;
 819                         break;
 820                 case 'N':
 821                         identity_new_passphrase = optarg;
 822                         break;
 823                 case 'C':
 824                         identity_comment = optarg;
 825                         break;
 826                 case 'q':
 827                         quiet = 1;
 828                         break;
 829                 case 'R':
 830                         /* unused */
 831                         exit(0);
 832                         break;
 833                 case 'e':
 834                 case 'x':
 835                         /* export key */
 836                         convert_to_ssh2 = 1;
 837                         break;
 838                 case 'i':
 839                 case 'X':
 840                         /* import key */
 841                         convert_from_ssh2 = 1;
 842                         break;
 843                 case 'y':
 844                         print_public = 1;
 845                         break;
 846                 case 'd':
 847                         key_type_name = "dsa";
 848                         break;
 849                 case 't':
 850                         key_type_name = optarg;
 851                         break;
 852                 case 'u':
 853                         reader = atoi(optarg); /*XXX*/
 854                         break;
 855                 case '?':
 856                 default:
 857                         usage();
 858                 }
 859         }
 860         if (optind < ac) {
 861                 printf("Too many arguments.\n");
 862                 usage();
 863         }
 864         if (change_passphrase && change_comment) {
 865                 printf("Can only have one of -p and -c.\n");
 866                 usage();
 867         }
 868         if (print_fingerprint || print_bubblebabble)
 869                 do_fingerprint(pw);
 870         if (change_passphrase)
 871                 do_change_passphrase(pw);
 872         if (change_comment)
 873                 do_change_comment(pw);
 874         if (convert_to_ssh2)
 875                 do_convert_to_ssh2(pw);
 876         if (convert_from_ssh2)
 877                 do_convert_from_ssh2(pw);
 878         if (print_public)
 879                 do_print_public(pw);
 880         if (reader != -1)
 881                 do_upload(pw, reader);
 882
 883         arc4random_stir();
 884
 885         type = key_type_from_name(key_type_name);
 886         if (type == KEY_UNSPEC) {
 887                 fprintf(stderr, "unknown key type %s\n", key_type_name);
 888                 exit(1);
 889         }
 890         if (!quiet)
 891                 printf("Generating public/private %s key pair.\n", key_type_name);
 892         private = key_generate(type, bits);
 893         if (private == NULL) {
 894                 fprintf(stderr, "key_generate failed");
 895                 exit(1);
 896         }
 897         public  = key_from_private(private);
 898
 899         if (!have_identity)
 900                 ask_filename(pw, "Enter file in which to save the key");
 901
 902         /* Create ~/.ssh directory if it doesn\'t already exist. */
 903         snprintf(dotsshdir, sizeof dotsshdir, "%s/%s", pw->pw_dir, _PATH_SSH_USER_DIR);
 904         if (strstr(identity_file, dotsshdir) != NULL &&
 905             stat(dotsshdir, &st) < 0) {
 906                 if (mkdir(dotsshdir, 0700) < 0)
 907                         error("Could not create directory '%s'.", dotsshdir);
 908                 else if (!quiet)
 909                         printf("Created directory '%s'.\n", dotsshdir);
 910         }
 911         /* If the file already exists, ask the user to confirm. */
 912         if (stat(identity_file, &st) >= 0) {
 913                 char yesno[3];
 914                 printf("%s already exists.\n", identity_file);
 915                 printf("Overwrite (y/n)? ");
 916                 fflush(stdout);
 917                 if (fgets(yesno, sizeof(yesno), stdin) == NULL)
 918                         exit(1);
 919                 if (yesno[0] != 'y' && yesno[0] != 'Y')
 920                         exit(1);
 921         }
 922         /* Ask for a passphrase (twice). */
 923         if (identity_passphrase)
 924                 passphrase1 = xstrdup(identity_passphrase);
 925         else if (identity_new_passphrase)
 926                 passphrase1 = xstrdup(identity_new_passphrase);
 927         else {
 928 passphrase_again:
 929                 passphrase1 =
 930                         read_passphrase("Enter passphrase (empty for no "
 931                             "passphrase): ", RP_ALLOW_STDIN);
 932                 passphrase2 = read_passphrase("Enter same passphrase again: ",
 933                     RP_ALLOW_STDIN);
 934                 if (strcmp(passphrase1, passphrase2) != 0) {
 935                         /*
 936                          * The passphrases do not match.  Clear them and
 937                          * retry.
 938                          */
 939                         memset(passphrase1, 0, strlen(passphrase1));
 940                         memset(passphrase2, 0, strlen(passphrase2));
 941                         xfree(passphrase1);
 942                         xfree(passphrase2);
 943                         printf("Passphrases do not match.  Try again.\n");
 944                         goto passphrase_again;
 945                 }
 946                 /* Clear the other copy of the passphrase. */
 947                 memset(passphrase2, 0, strlen(passphrase2));
 948                 xfree(passphrase2);
 949         }
 950
 951         if (identity_comment) {
 952                 strlcpy(comment, identity_comment, sizeof(comment));
 953         } else {
 954                 /* Create default commend field for the passphrase. */
 955                 snprintf(comment, sizeof comment, "%s@%s", pw->pw_name, hostname);
 956         }
 957
 958         /* Save the key with the given passphrase and comment. */
 959         if (!key_save_private(private, identity_file, passphrase1, comment)) {
 960                 printf("Saving the key failed: %s.\n", identity_file);
 961                 memset(passphrase1, 0, strlen(passphrase1));
 962                 xfree(passphrase1);
 963                 exit(1);
 964         }
 965         /* Clear the passphrase. */
 966         memset(passphrase1, 0, strlen(passphrase1));
 967         xfree(passphrase1);
 968
 969         /* Clear the private key and the random number generator. */
 970         key_free(private);
 971         arc4random_stir();
 972
 973         if (!quiet)
 974                 printf("Your identification has been saved in %s.\n", identity_file);
 975
 976         strlcat(identity_file, ".pub", sizeof(identity_file));
 977         fd = open(identity_file, O_WRONLY | O_CREAT | O_TRUNC, 0644);
 978         if (fd == -1) {
 979                 printf("Could not save your public key in %s\n", identity_file);
 980                 exit(1);
 981         }
 982         f = fdopen(fd, "w");
 983         if (f == NULL) {
 984                 printf("fdopen %s failed", identity_file);
 985                 exit(1);
 986         }
 987         if (!key_write(public, f))
 988                 fprintf(stderr, "write key failed");
 989         fprintf(f, " %s\n", comment);
 990         fclose(f);
 991
 992         if (!quiet) {
 993                 char *fp = key_fingerprint(public, SSH_FP_MD5, SSH_FP_HEX);
 994                 printf("Your public key has been saved in %s.\n",
 995                     identity_file);
 996                 printf("The key fingerprint is:\n");
 997                 printf("%s %s\n", fp, comment);
 998                 xfree(fp);
 999         }
1000
1001         key_free(public);
1002         exit(0);
1003 }