release/src-rt-6.x.4708/router/dropbear/dropbearkey.c

   1 /*
   2  * Dropbear - a SSH2 server
   3  *
   4  * Copyright (c) 2002,2003 Matt Johnston
   5  * All rights reserved.
   6  *
   7  * Permission is hereby granted, free of charge, to any person obtaining a copy
   8  * of this software and associated documentation files (the "Software"), to deal
   9  * in the Software without restriction, including without limitation the rights
  10  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  11  * copies of the Software, and to permit persons to whom the Software is
  12  * furnished to do so, subject to the following conditions:
  13  *
  14  * The above copyright notice and this permission notice shall be included in
  15  * all copies or substantial portions of the Software.
  16  *
  17  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  18  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  19  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
  20  * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  21  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  22  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  23  * SOFTWARE. */
  24
  25 /* The format of the keyfiles is basically a raw dump of the buffer. Data types
  26  * are specified in the transport rfc 4253 - string is a 32-bit len then the
  27  * non-null-terminated string, mp_int is a 32-bit len then the bignum data.
  28  * The actual functions are buf_put_rsa_priv_key() and buf_put_dss_priv_key()
  29
  30  * RSA:
  31  * string       "ssh-rsa"
  32  * mp_int       e
  33  * mp_int       n
  34  * mp_int       d
  35  * mp_int       p (newer versions only)
  36  * mp_int       q (newer versions only)
  37  *
  38  * DSS:
  39  * string       "ssh-dss"
  40  * mp_int       p
  41  * mp_int       q
  42  * mp_int       g
  43  * mp_int       y
  44  * mp_int       x
  45  *
  46  */
  47 #include "includes.h"
  48 #include "signkey.h"
  49 #include "buffer.h"
  50 #include "dbutil.h"
  51
  52 #include "genrsa.h"
  53 #include "gendss.h"
  54 #include "ecdsa.h"
  55 #include "crypto_desc.h"
  56 #include "dbrandom.h"
  57 #include "gensignkey.h"
  58
  59 static void printhelp(char * progname);
  60
  61
  62 static void printpubkey(sign_key * key, int keytype);
  63 static int printpubfile(const char* filename);
  64
  65 /* Print a help message */
  66 static void printhelp(char * progname) {
  67
  68         fprintf(stderr, "Usage: %s -t <type> -f <filename> [-s bits]\n"
  69                                         "-t type        Type of key to generate. One of:\n"
  70 #ifdef DROPBEAR_RSA
  71                                         "               rsa\n"
  72 #endif
  73 #ifdef DROPBEAR_DSS
  74                                         "               dss\n"
  75 #endif
  76 #ifdef DROPBEAR_ECDSA
  77                                         "               ecdsa\n"
  78 #endif
  79                                         "-f filename    Use filename for the secret key.\n"
  80                                         "               ~/.ssh/id_dropbear is recommended for client keys.\n"
  81                                         "-s bits        Key size in bits, should be a multiple of 8 (optional)\n"
  82 #ifdef DROPBEAR_DSS
  83                                         "           DSS has a fixed size of 1024 bits\n"
  84 #endif
  85 #ifdef DROPBEAR_ECDSA
  86                                         "           ECDSA has sizes "
  87 #ifdef DROPBEAR_ECC_256
  88                                         "256 "
  89 #endif
  90 #ifdef DROPBEAR_ECC_384
  91                                         "384 "
  92 #endif
  93 #ifdef DROPBEAR_ECC_521
  94                                         "521 "
  95 #endif
  96                                         "\n"
  97 #endif
  98                                         "-y             Just print the publickey and fingerprint for the\n              private key in <filename>.\n"
  99 #ifdef DEBUG_TRACE
 100                                         "-v             verbose\n"
 101 #endif
 102                                         ,progname);
 103 }
 104
 105 /* fails fatally */
 106 static void check_signkey_bits(enum signkey_type type, int bits)
 107 {
 108         switch (type) {
 109 #ifdef DROPBEAR_RSA
 110             case DROPBEAR_SIGNKEY_RSA:
 111                 if (bits < 512 || bits > 4096 || (bits % 8 != 0)) {
 112                         dropbear_exit("Bits must satisfy 512 <= bits <= 4096, and be a"
 113                             " multiple of 8\n");
 114                 }
 115                 break;
 116 #endif
 117 #ifdef DROPEAR_DSS
 118             case DROPBEAR_SIGNKEY_DSS:
 119                 if (bits != 1024) {
 120                     dropbear_exit("DSS keys have a fixed size of 1024 bits\n");
 121                     exit(EXIT_FAILURE);
 122                 }
 123 #endif
 124                         default:
 125                                 (void)0; /* quiet, compiler. ecdsa handles checks itself */
 126         }
 127 }
 128
 129 #if defined(DBMULTI_dropbearkey) || !defined(DROPBEAR_MULTI)
 130 #if defined(DBMULTI_dropbearkey) && defined(DROPBEAR_MULTI)
 131 int dropbearkey_main(int argc, char ** argv) {
 132 #else
 133 int main(int argc, char ** argv) {
 134 #endif
 135
 136         int i;
 137         char ** next = 0;
 138         char * filename = NULL;
 139         enum signkey_type keytype = DROPBEAR_SIGNKEY_NONE;
 140         char * typetext = NULL;
 141         char * sizetext = NULL;
 142         unsigned int bits = 0;
 143         int printpub = 0;
 144
 145         crypto_init();
 146         seedrandom();
 147
 148         /* get the commandline options */
 149         for (i = 1; i < argc; i++) {
 150                 if (argv[i] == NULL) {
 151                         continue; /* Whack */
 152                 }
 153                 if (next) {
 154                         *next = argv[i];
 155                         next = NULL;
 156                         continue;
 157                 }
 158
 159                 if (argv[i][0] == '-') {
 160                         switch (argv[i][1]) {
 161                                 case 'f':
 162                                         next = &filename;
 163                                         break;
 164                                 case 't':
 165                                         next = &typetext;
 166                                         break;
 167                                 case 's':
 168                                         next = &sizetext;
 169                                         break;
 170                                 case 'y':
 171                                         printpub = 1;
 172                                         break;
 173                                 case 'h':
 174                                         printhelp(argv[0]);
 175                                         exit(EXIT_SUCCESS);
 176                                         break;
 177 #ifdef DEBUG_TRACE
 178                                 case 'v':
 179                                         debug_trace = 1;
 180                                         break;
 181 #endif
 182                                 default:
 183                                         fprintf(stderr, "Unknown argument %s\n", argv[i]);
 184                                         printhelp(argv[0]);
 185                                         exit(EXIT_FAILURE);
 186                                         break;
 187                         }
 188                 }
 189         }
 190
 191         if (!filename) {
 192                 fprintf(stderr, "Must specify a key filename\n");
 193                 printhelp(argv[0]);
 194                 exit(EXIT_FAILURE);
 195         }
 196
 197         if (printpub) {
 198                 int ret = printpubfile(filename);
 199                 exit(ret);
 200         }
 201
 202         /* check/parse args */
 203         if (!typetext) {
 204                 fprintf(stderr, "Must specify key type\n");
 205                 printhelp(argv[0]);
 206                 exit(EXIT_FAILURE);
 207         }
 208
 209 #ifdef DROPBEAR_RSA
 210         if (strcmp(typetext, "rsa") == 0)
 211         {
 212                 keytype = DROPBEAR_SIGNKEY_RSA;
 213         }
 214 #endif
 215 #ifdef DROPBEAR_DSS
 216         if (strcmp(typetext, "dss") == 0)
 217         {
 218                 keytype = DROPBEAR_SIGNKEY_DSS;
 219         }
 220 #endif
 221 #ifdef DROPBEAR_ECDSA
 222         if (strcmp(typetext, "ecdsa") == 0)
 223         {
 224                 keytype = DROPBEAR_SIGNKEY_ECDSA_KEYGEN;
 225         }
 226 #endif
 227
 228         if (keytype == DROPBEAR_SIGNKEY_NONE) {
 229                 fprintf(stderr, "Unknown key type '%s'\n", typetext);
 230                 printhelp(argv[0]);
 231                 exit(EXIT_FAILURE);
 232         }
 233
 234         if (sizetext) {
 235                 if (sscanf(sizetext, "%u", &bits) != 1) {
 236                         fprintf(stderr, "Bits must be an integer\n");
 237                         exit(EXIT_FAILURE);
 238                 }
 239
 240                 check_signkey_bits(keytype, bits);;
 241     }
 242
 243         fprintf(stderr, "Generating key, this may take a while...\n");
 244     if (signkey_generate(keytype, bits, filename) == DROPBEAR_FAILURE)
 245     {
 246         dropbear_exit("Failed to generate key.\n");
 247     }
 248
 249         printpubfile(filename);
 250
 251         return EXIT_SUCCESS;
 252 }
 253 #endif
 254
 255 static int printpubfile(const char* filename) {
 256
 257         buffer *buf = NULL;
 258         sign_key *key = NULL;
 259         enum signkey_type keytype;
 260         int ret;
 261         int err = DROPBEAR_FAILURE;
 262
 263         buf = buf_new(MAX_PRIVKEY_SIZE);
 264         ret = buf_readfile(buf, filename);
 265
 266         if (ret != DROPBEAR_SUCCESS) {
 267                 fprintf(stderr, "Failed reading '%s'\n", filename);
 268                 goto out;
 269         }
 270
 271         key = new_sign_key();
 272         keytype = DROPBEAR_SIGNKEY_ANY;
 273
 274         buf_setpos(buf, 0);
 275         ret = buf_get_priv_key(buf, key, &keytype);
 276         if (ret == DROPBEAR_FAILURE) {
 277                 fprintf(stderr, "Bad key in '%s'\n", filename);
 278                 goto out;
 279         }
 280
 281         printpubkey(key, keytype);
 282
 283         err = DROPBEAR_SUCCESS;
 284
 285 out:
 286         buf_burn(buf);
 287         buf_free(buf);
 288         buf = NULL;
 289         if (key) {
 290                 sign_key_free(key);
 291                 key = NULL;
 292         }
 293         return err;
 294 }
 295
 296 static void printpubkey(sign_key * key, int keytype) {
 297
 298         buffer * buf = NULL;
 299         unsigned char base64key[MAX_PUBKEY_SIZE*2];
 300         unsigned long base64len;
 301         int err;
 302         const char * typestring = NULL;
 303         char *fp = NULL;
 304         int len;
 305         struct passwd * pw = NULL;
 306         char * username = NULL;
 307         char hostname[100];
 308
 309         buf = buf_new(MAX_PUBKEY_SIZE);
 310         buf_put_pub_key(buf, key, keytype);
 311         buf_setpos(buf, 4);
 312
 313         len = buf->len - buf->pos;
 314
 315         base64len = sizeof(base64key);
 316         err = base64_encode(buf_getptr(buf, len), len, base64key, &base64len);
 317
 318         if (err != CRYPT_OK) {
 319                 fprintf(stderr, "base64 failed");
 320         }
 321
 322         typestring = signkey_name_from_type(keytype, NULL);
 323
 324         fp = sign_key_fingerprint(buf_getptr(buf, len), len);
 325
 326         /* a user@host comment is informative */
 327         username = "";
 328         pw = getpwuid(getuid());
 329         if (pw) {
 330                 username = pw->pw_name;
 331         }
 332
 333         gethostname(hostname, sizeof(hostname));
 334         hostname[sizeof(hostname)-1] = '\0';
 335
 336         printf("Public key portion is:\n%s %s %s@%s\nFingerprint: %s\n",
 337                         typestring, base64key, username, hostname, fp);
 338
 339         m_free(fp);
 340         buf_free(buf);
 341 }