package/utils/px5g/px5g.c

   1 /*
   2  * px5g - Embedded x509 key and certificate generator based on PolarSSL
   3  *
   4  *   Copyright (C) 2009 Steven Barth <steven@midlink.org>
   5  *   Copyright (C) 2014 Felix Fietkau <nbd@nbd.name>
   6  *
   7  *  This library is free software; you can redistribute it and/or
   8  *  modify it under the terms of the GNU Lesser General Public
   9  *  License, version 2.1 as published by the Free Software Foundation.
  10  *
  11  *  This library is distributed in the hope that it will be useful,
  12  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14  *  Lesser General Public License for more details.
  15  *
  16  *  You should have received a copy of the GNU Lesser General Public
  17  *  License along with this library; if not, write to the Free Software
  18  *  Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
  19  *  MA  02110-1301  USA
  20  */
  21
  22 #include <sys/types.h>
  23
  24 #include <stdio.h>
  25 #include <stdlib.h>
  26 #include <string.h>
  27 #include <time.h>
  28 #include <limits.h>
  29 #include <unistd.h>
  30 #include <fcntl.h>
  31 #include <stdbool.h>
  32
  33 #include <mbedtls/bignum.h>
  34 #include <mbedtls/x509_crt.h>
  35 #include <mbedtls/ecp.h>
  36 #include <mbedtls/rsa.h>
  37 #include <mbedtls/pk.h>
  38
  39 #define PX5G_VERSION "0.2"
  40 #define PX5G_COPY "Copyright (c) 2009 Steven Barth <steven@midlink.org>"
  41 #define PX5G_LICENSE "Licensed under the GNU Lesser General Public License v2.1"
  42
  43 static int urandom_fd;
  44 static char buf[16384];
  45
  46 static int _urandom(void *ctx, unsigned char *out, size_t len)
  47 {
  48         read(urandom_fd, out, len);
  49         return 0;
  50 }
  51
  52 static void write_file(const char *path, int len, bool pem)
  53 {
  54         FILE *f = stdout;
  55         const char *buf_start = buf;
  56
  57         if (!pem)
  58                 buf_start += sizeof(buf) - len;
  59
  60         if (!len) {
  61                 fprintf(stderr, "No data to write\n");
  62                 exit(1);
  63         }
  64
  65         if (!f) {
  66                 fprintf(stderr, "error: I/O error\n");
  67                 exit(1);
  68         }
  69
  70         if (path)
  71                 f = fopen(path, "w");
  72
  73         fwrite(buf_start, 1, len, f);
  74         fclose(f);
  75 }
  76
  77 static mbedtls_ecp_group_id ecp_curve(const char *name)
  78 {
  79         const mbedtls_ecp_curve_info *curve_info;
  80
  81         if (!strcmp(name, "P-256"))
  82                 return MBEDTLS_ECP_DP_SECP256R1;
  83         else if (!strcmp(name, "P-384"))
  84                 return MBEDTLS_ECP_DP_SECP384R1;
  85         else if (!strcmp(name, "P-521"))
  86                 return MBEDTLS_ECP_DP_SECP521R1;
  87         curve_info = mbedtls_ecp_curve_info_from_name(name);
  88         if (curve_info == NULL)
  89                 return MBEDTLS_ECP_DP_NONE;
  90         else
  91                 return curve_info->grp_id;
  92 }
  93
  94 static void write_key(mbedtls_pk_context *key, const char *path, bool pem)
  95 {
  96         int len = 0;
  97
  98         if (pem) {
  99                 if (mbedtls_pk_write_key_pem(key, (void *) buf, sizeof(buf)) == 0)
 100                         len = strlen(buf);
 101         } else {
 102                 len = mbedtls_pk_write_key_der(key, (void *) buf, sizeof(buf));
 103                 if (len < 0)
 104                         len = 0;
 105         }
 106
 107         write_file(path, len, pem);
 108 }
 109
 110 static void gen_key(mbedtls_pk_context *key, bool rsa, int ksize, int exp,
 111                     mbedtls_ecp_group_id curve, bool pem)
 112 {
 113         mbedtls_pk_init(key);
 114         if (rsa) {
 115                 fprintf(stderr, "Generating RSA private key, %i bit long modulus\n", ksize);
 116                 mbedtls_pk_setup(key, mbedtls_pk_info_from_type(MBEDTLS_PK_RSA));
 117                 if (!mbedtls_rsa_gen_key(mbedtls_pk_rsa(*key), _urandom, NULL, ksize, exp))
 118                         return;
 119         } else {
 120                 fprintf(stderr, "Generating EC private key\n");
 121                 mbedtls_pk_setup(key, mbedtls_pk_info_from_type(MBEDTLS_PK_ECKEY));
 122                 if (!mbedtls_ecp_gen_key(curve, mbedtls_pk_ec(*key), _urandom, NULL))
 123                         return;
 124         }
 125         fprintf(stderr, "error: key generation failed\n");
 126         exit(1);
 127 }
 128
 129 int dokey(bool rsa, char **arg)
 130 {
 131         mbedtls_pk_context key;
 132         unsigned int ksize = 512;
 133         int exp = 65537;
 134         char *path = NULL;
 135         bool pem = true;
 136         mbedtls_ecp_group_id curve = MBEDTLS_ECP_DP_SECP256R1;
 137
 138         while (*arg && **arg == '-') {
 139                 if (!strcmp(*arg, "-out") && arg[1]) {
 140                         path = arg[1];
 141                         arg++;
 142                 } else if (!strcmp(*arg, "-3")) {
 143                         exp = 3;
 144                 } else if (!strcmp(*arg, "-der")) {
 145                         pem = false;
 146                 }
 147                 arg++;
 148         }
 149
 150         if (*arg && rsa) {
 151                 ksize = (unsigned int)atoi(*arg);
 152         } else if (*arg) {
 153                 curve = ecp_curve((const char *)*arg);
 154                 if (curve == MBEDTLS_ECP_DP_NONE) {
 155                         fprintf(stderr, "error: invalid curve name: %s\n", *arg);
 156                         return 1;
 157                 }
 158         }
 159
 160         gen_key(&key, rsa, ksize, exp, curve, pem);
 161         write_key(&key, path, pem);
 162
 163         mbedtls_pk_free(&key);
 164
 165         return 0;
 166 }
 167
 168 int selfsigned(char **arg)
 169 {
 170         mbedtls_pk_context key;
 171         mbedtls_x509write_cert cert;
 172         mbedtls_mpi serial;
 173
 174         char *subject = "";
 175         unsigned int ksize = 512;
 176         int exp = 65537;
 177         unsigned int days = 30;
 178         char *keypath = NULL, *certpath = NULL;
 179         bool pem = true;
 180         time_t from = time(NULL), to;
 181         char fstr[20], tstr[20], sstr[17];
 182         int len;
 183         bool rsa = true;
 184         mbedtls_ecp_group_id curve = MBEDTLS_ECP_DP_SECP256R1;
 185
 186         while (*arg && **arg == '-') {
 187                 if (!strcmp(*arg, "-der")) {
 188                         pem = false;
 189                 } else if (!strcmp(*arg, "-newkey") && arg[1]) {
 190                         if (!strncmp(arg[1], "rsa:", 4)) {
 191                                 rsa = true;
 192                                 ksize = (unsigned int)atoi(arg[1] + 4);
 193                         } else if (!strcmp(arg[1], "ec")) {
 194                                 rsa = false;
 195                         } else {
 196                                 fprintf(stderr, "error: invalid algorithm\n");
 197                                 return 1;
 198                         }
 199                         arg++;
 200                 } else if (!strcmp(*arg, "-days") && arg[1]) {
 201                         days = (unsigned int)atoi(arg[1]);
 202                         arg++;
 203                 } else if (!strcmp(*arg, "-pkeyopt") && arg[1]) {
 204                         if (strncmp(arg[1], "ec_paramgen_curve:", 18)) {
 205                                 fprintf(stderr, "error: invalid pkey option: %s\n", arg[1]);
 206                                 return 1;
 207                         }
 208                         curve = ecp_curve((const char *)(arg[1] + 18));
 209                         if (curve == MBEDTLS_ECP_DP_NONE) {
 210                                 fprintf(stderr, "error: invalid curve name: %s\n", arg[1] + 18);
 211                                 return 1;
 212                         }
 213                         arg++;
 214                 } else if (!strcmp(*arg, "-keyout") && arg[1]) {
 215                         keypath = arg[1];
 216                         arg++;
 217                 } else if (!strcmp(*arg, "-out") && arg[1]) {
 218                         certpath = arg[1];
 219                         arg++;
 220                 } else if (!strcmp(*arg, "-subj") && arg[1]) {
 221                         if (arg[1][0] != '/' || strchr(arg[1], ';')) {
 222                                 fprintf(stderr, "error: invalid subject");
 223                                 return 1;
 224                         }
 225                         subject = calloc(strlen(arg[1]) + 1, 1);
 226                         char *oldc = arg[1] + 1, *newc = subject, *delim;
 227                         do {
 228                                 delim = strchr(oldc, '=');
 229                                 if (!delim) {
 230                                         fprintf(stderr, "error: invalid subject");
 231                                         return 1;
 232                                 }
 233                                 memcpy(newc, oldc, delim - oldc + 1);
 234                                 newc += delim - oldc + 1;
 235                                 oldc = delim + 1;
 236
 237                                 delim = strchr(oldc, '/');
 238                                 if (!delim) {
 239                                         delim = arg[1] + strlen(arg[1]);
 240                                 }
 241                                 memcpy(newc, oldc, delim - oldc);
 242                                 newc += delim - oldc;
 243                                 *newc++ = ',';
 244                                 oldc = delim + 1;
 245                         } while(*delim);
 246                         arg++;
 247                 }
 248                 arg++;
 249         }
 250         gen_key(&key, rsa, ksize, exp, curve, pem);
 251
 252         if (keypath)
 253                 write_key(&key, keypath, pem);
 254
 255         from = (from < 1000000000) ? 1000000000 : from;
 256         strftime(fstr, sizeof(fstr), "%Y%m%d%H%M%S", gmtime(&from));
 257         to = from + 60 * 60 * 24 * days;
 258         if (to < from)
 259                 to = INT_MAX;
 260         strftime(tstr, sizeof(tstr), "%Y%m%d%H%M%S", gmtime(&to));
 261
 262         fprintf(stderr, "Generating selfsigned certificate with subject '%s'"
 263                         " and validity %s-%s\n", subject, fstr, tstr);
 264
 265         mbedtls_x509write_crt_init(&cert);
 266         mbedtls_x509write_crt_set_md_alg(&cert, MBEDTLS_MD_SHA256);
 267         mbedtls_x509write_crt_set_issuer_key(&cert, &key);
 268         mbedtls_x509write_crt_set_subject_key(&cert, &key);
 269         mbedtls_x509write_crt_set_subject_name(&cert, subject);
 270         mbedtls_x509write_crt_set_issuer_name(&cert, subject);
 271         mbedtls_x509write_crt_set_validity(&cert, fstr, tstr);
 272         mbedtls_x509write_crt_set_basic_constraints(&cert, 0, -1);
 273         mbedtls_x509write_crt_set_subject_key_identifier(&cert);
 274         mbedtls_x509write_crt_set_authority_key_identifier(&cert);
 275
 276         _urandom(NULL, (void *) buf, 8);
 277         for (len = 0; len < 8; len++)
 278                 sprintf(sstr + len*2, "%02x", (unsigned char) buf[len]);
 279
 280         mbedtls_mpi_init(&serial);
 281         mbedtls_mpi_read_string(&serial, 16, sstr);
 282         mbedtls_x509write_crt_set_serial(&cert, &serial);
 283
 284         if (pem) {
 285                 if (mbedtls_x509write_crt_pem(&cert, (void *) buf, sizeof(buf), _urandom, NULL) < 0) {
 286                         fprintf(stderr, "Failed to generate certificate\n");
 287                         return 1;
 288                 }
 289
 290                 len = strlen(buf);
 291         } else {
 292                 len = mbedtls_x509write_crt_der(&cert, (void *) buf, sizeof(buf), _urandom, NULL);
 293                 if (len < 0) {
 294                         fprintf(stderr, "Failed to generate certificate: %d\n", len);
 295                         return 1;
 296                 }
 297         }
 298         write_file(certpath, len, pem);
 299
 300         mbedtls_x509write_crt_free(&cert);
 301         mbedtls_mpi_free(&serial);
 302         mbedtls_pk_free(&key);
 303
 304         return 0;
 305 }
 306
 307 int main(int argc, char *argv[])
 308 {
 309         urandom_fd = open("/dev/urandom", O_RDONLY);
 310
 311         if (!argv[1]) {
 312                 //Usage
 313         } else if (!strcmp(argv[1], "eckey")) {
 314                 return dokey(false, argv+2);
 315         } else if (!strcmp(argv[1], "rsakey")) {
 316                 return dokey(true, argv+2);
 317         } else if (!strcmp(argv[1], "selfsigned")) {
 318                 return selfsigned(argv+2);
 319         }
 320
 321         fprintf(stderr,
 322                 "PX5G X.509 Certificate Generator Utility v" PX5G_VERSION "\n" PX5G_COPY
 323                 "\nbased on PolarSSL by Christophe Devine and Paul Bakker\n\n");
 324         fprintf(stderr, "Usage: %s [eckey|rsakey|selfsigned]\n", *argv);
 325         return 1;
 326 }