ustream-openssl.c

   1 /*
   2  * ustream-ssl - library for SSL over ustream
   3  *
   4  * Copyright (C) 2012 Felix Fietkau <nbd@openwrt.org>
   5  *
   6  * Permission to use, copy, modify, and/or distribute this software for any
   7  * purpose with or without fee is hereby granted, provided that the above
   8  * copyright notice and this permission notice appear in all copies.
   9  *
  10  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
  11  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
  12  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
  13  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
  14  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
  15  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
  16  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  17  */
  18
  19 #include <ctype.h>
  20 #include <openssl/x509v3.h>
  21 #include "ustream-ssl.h"
  22 #include "ustream-internal.h"
  23
  24 __hidden struct ustream_ssl_ctx *
  25 __ustream_ssl_context_new(bool server)
  26 {
  27         static bool _init = false;
  28         const void *m;
  29         SSL_CTX *c;
  30
  31         if (!_init) {
  32                 SSL_load_error_strings();
  33                 SSL_library_init();
  34                 _init = true;
  35         }
  36
  37 #ifdef CYASSL_OPENSSL_H_
  38         if (server)
  39                 m = SSLv23_server_method();
  40         else
  41                 m = SSLv23_client_method();
  42 #else
  43         if (server)
  44                 m = TLSv1_server_method();
  45         else
  46                 m = TLSv1_client_method();
  47 #endif
  48
  49         c = SSL_CTX_new((void *) m);
  50         if (!c)
  51                 return NULL;
  52
  53         SSL_CTX_set_verify(c, SSL_VERIFY_NONE, NULL);
  54
  55         return (void *) c;
  56 }
  57
  58 __hidden int __ustream_ssl_add_ca_crt_file(struct ustream_ssl_ctx *ctx, const char *file)
  59 {
  60         int ret;
  61
  62         ret = SSL_CTX_load_verify_locations((void *) ctx, file, NULL);
  63         if (ret < 1)
  64                 return -1;
  65
  66         return 0;
  67 }
  68
  69 __hidden int __ustream_ssl_set_crt_file(struct ustream_ssl_ctx *ctx, const char *file)
  70 {
  71         int ret;
  72
  73         ret = SSL_CTX_use_certificate_chain_file((void *) ctx, file);
  74         if (ret < 1)
  75                 ret = SSL_CTX_use_certificate_file((void *) ctx, file, SSL_FILETYPE_ASN1);
  76
  77         if (ret < 1)
  78                 return -1;
  79
  80         return 0;
  81 }
  82
  83 __hidden int __ustream_ssl_set_key_file(struct ustream_ssl_ctx *ctx, const char *file)
  84 {
  85         int ret;
  86
  87         ret = SSL_CTX_use_PrivateKey_file((void *) ctx, file, SSL_FILETYPE_PEM);
  88         if (ret < 1)
  89                 ret = SSL_CTX_use_PrivateKey_file((void *) ctx, file, SSL_FILETYPE_ASN1);
  90
  91         if (ret < 1)
  92                 return -1;
  93
  94         return 0;
  95 }
  96
  97 __hidden void __ustream_ssl_context_free(struct ustream_ssl_ctx *ctx)
  98 {
  99         SSL_CTX_free((void *) ctx);
 100 }
 101
 102 static void ustream_ssl_error(struct ustream_ssl *us, int ret)
 103 {
 104         us->error = ret;
 105         uloop_timeout_set(&us->error_timer, 0);
 106 }
 107
 108 static bool host_pattern_match(const unsigned char *pattern, const char *cn)
 109 {
 110         char c;
 111
 112         for (; (c = tolower(*pattern++)) != 0; cn++) {
 113                 if (c != '*') {
 114                         if (c != *cn)
 115                                 return false;
 116                         continue;
 117                 }
 118
 119                 do {
 120                         c = tolower(*pattern++);
 121                 } while (c == '*');
 122
 123                 while (*cn) {
 124                         if (c == tolower(*cn) &&
 125                             host_pattern_match(pattern, cn))
 126                                 return true;
 127                         if (*cn == '.')
 128                                 return false;
 129                         cn++;
 130                 }
 131
 132                 return !c;
 133         }
 134         return !*cn;
 135 }
 136
 137 static bool host_pattern_match_asn1(ASN1_STRING *asn1, const char *cn)
 138 {
 139         unsigned char *pattern;
 140         bool ret = false;
 141
 142         if (ASN1_STRING_to_UTF8(&pattern, asn1) < 0)
 143                 return false;
 144
 145         if (!pattern)
 146                 return false;
 147
 148         if (strlen((char *) pattern) == ASN1_STRING_length(asn1))
 149                 ret = host_pattern_match(pattern, cn);
 150
 151         OPENSSL_free(pattern);
 152
 153         return ret;
 154 }
 155
 156 static bool ustream_ssl_verify_cn_alt(struct ustream_ssl *us, X509 *cert)
 157 {
 158         GENERAL_NAMES *alt_names;
 159         int i, n_alt;
 160
 161         alt_names = X509_get_ext_d2i (cert, NID_subject_alt_name, NULL, NULL);
 162         if (!alt_names)
 163                 return false;
 164
 165         n_alt = sk_GENERAL_NAME_num(alt_names);
 166         for (i = 0; i < n_alt; i++) {
 167                 const GENERAL_NAME *name = sk_GENERAL_NAME_value(alt_names, i);
 168
 169                 if (!name)
 170                         continue;
 171
 172                 if (name->type != GEN_DNS)
 173                         continue;
 174
 175                 if (host_pattern_match_asn1(name->d.dNSName, us->peer_cn))
 176                         return true;
 177         }
 178
 179         return false;
 180 }
 181
 182 static bool ustream_ssl_verify_cn(struct ustream_ssl *us, X509 *cert)
 183 {
 184         ASN1_STRING *astr;
 185         X509_NAME *xname;
 186         int i, last;
 187
 188         if (!us->peer_cn)
 189                 return false;
 190
 191         if (ustream_ssl_verify_cn_alt(us, cert))
 192                 return true;
 193
 194         xname = X509_get_subject_name(cert);
 195
 196         last = -1;
 197         while (1) {
 198                 i = X509_NAME_get_index_by_NID(xname, NID_commonName, last);
 199                 if (i < 0)
 200                         break;
 201
 202                 last = i;
 203         }
 204
 205         if (last < 0)
 206                 return false;
 207
 208         astr = X509_NAME_ENTRY_get_data(X509_NAME_get_entry(xname, last));
 209
 210         return host_pattern_match_asn1(astr, us->peer_cn);
 211 }
 212
 213
 214 static void ustream_ssl_verify_cert(struct ustream_ssl *us)
 215 {
 216         void *ssl = us->ssl;
 217         X509 *cert;
 218         int res;
 219
 220         cert = SSL_get_peer_certificate(ssl);
 221         if (!cert)
 222                 return;
 223
 224         res = SSL_get_verify_result(ssl);
 225         if (res != X509_V_OK) {
 226                 if (us->notify_verify_error)
 227                         us->notify_verify_error(us, res, X509_verify_cert_error_string(res));
 228                 return;
 229         }
 230
 231         us->valid_cert = true;
 232         us->valid_cn = ustream_ssl_verify_cn(us, cert);
 233 }
 234
 235 __hidden enum ssl_conn_status __ustream_ssl_connect(struct ustream_ssl *us)
 236 {
 237         void *ssl = us->ssl;
 238         int r;
 239
 240         if (us->server)
 241                 r = SSL_accept(ssl);
 242         else
 243                 r = SSL_connect(ssl);
 244
 245         if (r == 1) {
 246                 ustream_ssl_verify_cert(us);
 247                 return U_SSL_OK;
 248         }
 249
 250         r = SSL_get_error(ssl, r);
 251         if (r == SSL_ERROR_WANT_READ || r == SSL_ERROR_WANT_WRITE)
 252                 return U_SSL_PENDING;
 253
 254         ustream_ssl_error(us, r);
 255         return U_SSL_ERROR;
 256 }
 257
 258 __hidden int __ustream_ssl_write(struct ustream_ssl *us, const char *buf, int len)
 259 {
 260         void *ssl = us->ssl;
 261         int ret = SSL_write(ssl, buf, len);
 262
 263         if (ret < 0) {
 264                 int err = SSL_get_error(ssl, ret);
 265                 if (err == SSL_ERROR_WANT_WRITE)
 266                         return 0;
 267
 268                 ustream_ssl_error(us, err);
 269                 return -1;
 270         }
 271
 272         return ret;
 273 }
 274
 275 __hidden int __ustream_ssl_read(struct ustream_ssl *us, char *buf, int len)
 276 {
 277         int ret = SSL_read(us->ssl, buf, len);
 278
 279         if (ret < 0) {
 280                 ret = SSL_get_error(us->ssl, ret);
 281                 if (ret == SSL_ERROR_WANT_READ)
 282                         return U_SSL_PENDING;
 283
 284                 ustream_ssl_error(us, ret);
 285                 return U_SSL_ERROR;
 286         }
 287
 288         return ret;
 289 }
 290