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 <string.h>
  20 #include <ctype.h>
  21 #include <openssl/x509v3.h>
  22 #include "ustream-ssl.h"
  23 #include "ustream-internal.h"
  24
  25 __hidden struct ustream_ssl_ctx *
  26 __ustream_ssl_context_new(bool server)
  27 {
  28         static bool _init = false;
  29         const void *m;
  30         SSL_CTX *c;
  31
  32         if (!_init) {
  33                 SSL_load_error_strings();
  34                 SSL_library_init();
  35                 _init = true;
  36         }
  37
  38 #ifdef CYASSL_OPENSSL_H_
  39         if (server)
  40                 m = SSLv23_server_method();
  41         else
  42                 m = SSLv23_client_method();
  43 #else
  44         if (server)
  45                 m = TLSv1_server_method();
  46         else
  47                 m = TLSv1_client_method();
  48 #endif
  49
  50         c = SSL_CTX_new((void *) m);
  51         if (!c)
  52                 return NULL;
  53
  54         SSL_CTX_set_verify(c, SSL_VERIFY_NONE, NULL);
  55
  56         return (void *) c;
  57 }
  58
  59 __hidden int __ustream_ssl_add_ca_crt_file(struct ustream_ssl_ctx *ctx, const char *file)
  60 {
  61         int ret;
  62
  63         ret = SSL_CTX_load_verify_locations((void *) ctx, file, NULL);
  64         if (ret < 1)
  65                 return -1;
  66
  67         return 0;
  68 }
  69
  70 __hidden int __ustream_ssl_set_crt_file(struct ustream_ssl_ctx *ctx, const char *file)
  71 {
  72         int ret;
  73
  74         ret = SSL_CTX_use_certificate_chain_file((void *) ctx, file);
  75         if (ret < 1)
  76                 ret = SSL_CTX_use_certificate_file((void *) ctx, file, SSL_FILETYPE_ASN1);
  77
  78         if (ret < 1)
  79                 return -1;
  80
  81         return 0;
  82 }
  83
  84 __hidden int __ustream_ssl_set_key_file(struct ustream_ssl_ctx *ctx, const char *file)
  85 {
  86         int ret;
  87
  88         ret = SSL_CTX_use_PrivateKey_file((void *) ctx, file, SSL_FILETYPE_PEM);
  89         if (ret < 1)
  90                 ret = SSL_CTX_use_PrivateKey_file((void *) ctx, file, SSL_FILETYPE_ASN1);
  91
  92         if (ret < 1)
  93                 return -1;
  94
  95         return 0;
  96 }
  97
  98 __hidden void __ustream_ssl_context_free(struct ustream_ssl_ctx *ctx)
  99 {
 100         SSL_CTX_free((void *) ctx);
 101 }
 102
 103 static void ustream_ssl_error(struct ustream_ssl *us, int ret)
 104 {
 105         us->error = ret;
 106         uloop_timeout_set(&us->error_timer, 0);
 107 }
 108
 109 #ifndef CYASSL_OPENSSL_H_
 110
 111 static bool host_pattern_match(const unsigned char *pattern, const char *cn)
 112 {
 113         char c;
 114
 115         for (; (c = tolower(*pattern++)) != 0; cn++) {
 116                 if (c != '*') {
 117                         if (c != *cn)
 118                                 return false;
 119                         continue;
 120                 }
 121
 122                 do {
 123                         c = tolower(*pattern++);
 124                 } while (c == '*');
 125
 126                 while (*cn) {
 127                         if (c == tolower(*cn) &&
 128                             host_pattern_match(pattern, cn))
 129                                 return true;
 130                         if (*cn == '.')
 131                                 return false;
 132                         cn++;
 133                 }
 134
 135                 return !c;
 136         }
 137         return !*cn;
 138 }
 139
 140 static bool host_pattern_match_asn1(ASN1_STRING *asn1, const char *cn)
 141 {
 142         unsigned char *pattern;
 143         bool ret = false;
 144
 145         if (ASN1_STRING_to_UTF8(&pattern, asn1) < 0)
 146                 return false;
 147
 148         if (!pattern)
 149                 return false;
 150
 151         if (strlen((char *) pattern) == ASN1_STRING_length(asn1))
 152                 ret = host_pattern_match(pattern, cn);
 153
 154         OPENSSL_free(pattern);
 155
 156         return ret;
 157 }
 158
 159 static bool ustream_ssl_verify_cn_alt(struct ustream_ssl *us, X509 *cert)
 160 {
 161         GENERAL_NAMES *alt_names;
 162         int i, n_alt;
 163         bool ret = false;
 164
 165         alt_names = X509_get_ext_d2i (cert, NID_subject_alt_name, NULL, NULL);
 166         if (!alt_names)
 167                 return false;
 168
 169         n_alt = sk_GENERAL_NAME_num(alt_names);
 170         for (i = 0; i < n_alt; i++) {
 171                 const GENERAL_NAME *name = sk_GENERAL_NAME_value(alt_names, i);
 172
 173                 if (!name)
 174                         continue;
 175
 176                 if (name->type != GEN_DNS)
 177                         continue;
 178
 179                 if (host_pattern_match_asn1(name->d.dNSName, us->peer_cn)) {
 180                         ret = true;
 181                         break;
 182                 }
 183         }
 184
 185         sk_GENERAL_NAME_free(alt_names);
 186         return ret;
 187 }
 188
 189 static bool ustream_ssl_verify_cn(struct ustream_ssl *us, X509 *cert)
 190 {
 191         ASN1_STRING *astr;
 192         X509_NAME *xname;
 193         int i, last;
 194
 195         if (!us->peer_cn)
 196                 return false;
 197
 198         if (ustream_ssl_verify_cn_alt(us, cert))
 199                 return true;
 200
 201         xname = X509_get_subject_name(cert);
 202
 203         last = -1;
 204         while (1) {
 205                 i = X509_NAME_get_index_by_NID(xname, NID_commonName, last);
 206                 if (i < 0)
 207                         break;
 208
 209                 last = i;
 210         }
 211
 212         if (last < 0)
 213                 return false;
 214
 215         astr = X509_NAME_ENTRY_get_data(X509_NAME_get_entry(xname, last));
 216
 217         return host_pattern_match_asn1(astr, us->peer_cn);
 218 }
 219
 220
 221 static void ustream_ssl_verify_cert(struct ustream_ssl *us)
 222 {
 223         void *ssl = us->ssl;
 224         X509 *cert;
 225         int res;
 226
 227         res = SSL_get_verify_result(ssl);
 228         if (res != X509_V_OK) {
 229                 if (us->notify_verify_error)
 230                         us->notify_verify_error(us, res, X509_verify_cert_error_string(res));
 231                 return;
 232         }
 233
 234         cert = SSL_get_peer_certificate(ssl);
 235         if (!cert)
 236                 return;
 237
 238         us->valid_cert = true;
 239         us->valid_cn = ustream_ssl_verify_cn(us, cert);
 240         X509_free(cert);
 241 }
 242
 243 #endif
 244
 245 __hidden enum ssl_conn_status __ustream_ssl_connect(struct ustream_ssl *us)
 246 {
 247         void *ssl = us->ssl;
 248         int r;
 249
 250         if (us->server)
 251                 r = SSL_accept(ssl);
 252         else
 253                 r = SSL_connect(ssl);
 254
 255         if (r == 1) {
 256 #ifndef CYASSL_OPENSSL_H_
 257                 ustream_ssl_verify_cert(us);
 258 #endif
 259                 return U_SSL_OK;
 260         }
 261
 262         r = SSL_get_error(ssl, r);
 263         if (r == SSL_ERROR_WANT_READ || r == SSL_ERROR_WANT_WRITE)
 264                 return U_SSL_PENDING;
 265
 266         ustream_ssl_error(us, r);
 267         return U_SSL_ERROR;
 268 }
 269
 270 __hidden int __ustream_ssl_write(struct ustream_ssl *us, const char *buf, int len)
 271 {
 272         void *ssl = us->ssl;
 273         int ret = SSL_write(ssl, buf, len);
 274
 275         if (ret < 0) {
 276                 int err = SSL_get_error(ssl, ret);
 277                 if (err == SSL_ERROR_WANT_WRITE)
 278                         return 0;
 279
 280                 ustream_ssl_error(us, err);
 281                 return -1;
 282         }
 283
 284         return ret;
 285 }
 286
 287 __hidden int __ustream_ssl_read(struct ustream_ssl *us, char *buf, int len)
 288 {
 289         int ret = SSL_read(us->ssl, buf, len);
 290
 291         if (ret < 0) {
 292                 ret = SSL_get_error(us->ssl, ret);
 293                 if (ret == SSL_ERROR_WANT_READ)
 294                         return U_SSL_PENDING;
 295
 296                 ustream_ssl_error(us, ret);
 297                 return U_SSL_ERROR;
 298         }
 299
 300         return ret;
 301 }
 302