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         SSL_CTX_set_quiet_shutdown(c, 1);
  56
  57         return (void *) c;
  58 }
  59
  60 __hidden int __ustream_ssl_add_ca_crt_file(struct ustream_ssl_ctx *ctx, const char *file)
  61 {
  62         int ret;
  63
  64         ret = SSL_CTX_load_verify_locations((void *) ctx, file, NULL);
  65         if (ret < 1)
  66                 return -1;
  67
  68         return 0;
  69 }
  70
  71 __hidden int __ustream_ssl_set_crt_file(struct ustream_ssl_ctx *ctx, const char *file)
  72 {
  73         int ret;
  74
  75         ret = SSL_CTX_use_certificate_chain_file((void *) ctx, file);
  76         if (ret < 1)
  77                 ret = SSL_CTX_use_certificate_file((void *) ctx, file, SSL_FILETYPE_ASN1);
  78
  79         if (ret < 1)
  80                 return -1;
  81
  82         return 0;
  83 }
  84
  85 __hidden int __ustream_ssl_set_key_file(struct ustream_ssl_ctx *ctx, const char *file)
  86 {
  87         int ret;
  88
  89         ret = SSL_CTX_use_PrivateKey_file((void *) ctx, file, SSL_FILETYPE_PEM);
  90         if (ret < 1)
  91                 ret = SSL_CTX_use_PrivateKey_file((void *) ctx, file, SSL_FILETYPE_ASN1);
  92
  93         if (ret < 1)
  94                 return -1;
  95
  96         return 0;
  97 }
  98
  99 __hidden void __ustream_ssl_context_free(struct ustream_ssl_ctx *ctx)
 100 {
 101         SSL_CTX_free((void *) ctx);
 102 }
 103
 104 void __ustream_ssl_session_free(void *ssl)
 105 {
 106         SSL_shutdown(ssl);
 107         SSL_free(ssl);
 108 }
 109
 110 static void ustream_ssl_error(struct ustream_ssl *us, int ret)
 111 {
 112         us->error = ret;
 113         uloop_timeout_set(&us->error_timer, 0);
 114 }
 115
 116 #ifndef CYASSL_OPENSSL_H_
 117
 118 static bool host_pattern_match(const unsigned char *pattern, const char *cn)
 119 {
 120         char c;
 121
 122         for (; (c = tolower(*pattern++)) != 0; cn++) {
 123                 if (c != '*') {
 124                         if (c != *cn)
 125                                 return false;
 126                         continue;
 127                 }
 128
 129                 do {
 130                         c = tolower(*pattern++);
 131                 } while (c == '*');
 132
 133                 while (*cn) {
 134                         if (c == tolower(*cn) &&
 135                             host_pattern_match(pattern, cn))
 136                                 return true;
 137                         if (*cn == '.')
 138                                 return false;
 139                         cn++;
 140                 }
 141
 142                 return !c;
 143         }
 144         return !*cn;
 145 }
 146
 147 static bool host_pattern_match_asn1(ASN1_STRING *asn1, const char *cn)
 148 {
 149         unsigned char *pattern;
 150         bool ret = false;
 151
 152         if (ASN1_STRING_to_UTF8(&pattern, asn1) < 0)
 153                 return false;
 154
 155         if (!pattern)
 156                 return false;
 157
 158         if (strlen((char *) pattern) == ASN1_STRING_length(asn1))
 159                 ret = host_pattern_match(pattern, cn);
 160
 161         OPENSSL_free(pattern);
 162
 163         return ret;
 164 }
 165
 166 static bool ustream_ssl_verify_cn_alt(struct ustream_ssl *us, X509 *cert)
 167 {
 168         GENERAL_NAMES *alt_names;
 169         int i, n_alt;
 170         bool ret = false;
 171
 172         alt_names = X509_get_ext_d2i (cert, NID_subject_alt_name, NULL, NULL);
 173         if (!alt_names)
 174                 return false;
 175
 176         n_alt = sk_GENERAL_NAME_num(alt_names);
 177         for (i = 0; i < n_alt; i++) {
 178                 const GENERAL_NAME *name = sk_GENERAL_NAME_value(alt_names, i);
 179
 180                 if (!name)
 181                         continue;
 182
 183                 if (name->type != GEN_DNS)
 184                         continue;
 185
 186                 if (host_pattern_match_asn1(name->d.dNSName, us->peer_cn)) {
 187                         ret = true;
 188                         break;
 189                 }
 190         }
 191
 192         sk_GENERAL_NAME_free(alt_names);
 193         return ret;
 194 }
 195
 196 static bool ustream_ssl_verify_cn(struct ustream_ssl *us, X509 *cert)
 197 {
 198         ASN1_STRING *astr;
 199         X509_NAME *xname;
 200         int i, last;
 201
 202         if (!us->peer_cn)
 203                 return false;
 204
 205         if (ustream_ssl_verify_cn_alt(us, cert))
 206                 return true;
 207
 208         xname = X509_get_subject_name(cert);
 209
 210         last = -1;
 211         while (1) {
 212                 i = X509_NAME_get_index_by_NID(xname, NID_commonName, last);
 213                 if (i < 0)
 214                         break;
 215
 216                 last = i;
 217         }
 218
 219         if (last < 0)
 220                 return false;
 221
 222         astr = X509_NAME_ENTRY_get_data(X509_NAME_get_entry(xname, last));
 223
 224         return host_pattern_match_asn1(astr, us->peer_cn);
 225 }
 226
 227
 228 static void ustream_ssl_verify_cert(struct ustream_ssl *us)
 229 {
 230         void *ssl = us->ssl;
 231         X509 *cert;
 232         int res;
 233
 234         res = SSL_get_verify_result(ssl);
 235         if (res != X509_V_OK) {
 236                 if (us->notify_verify_error)
 237                         us->notify_verify_error(us, res, X509_verify_cert_error_string(res));
 238                 return;
 239         }
 240
 241         cert = SSL_get_peer_certificate(ssl);
 242         if (!cert)
 243                 return;
 244
 245         us->valid_cert = true;
 246         us->valid_cn = ustream_ssl_verify_cn(us, cert);
 247         X509_free(cert);
 248 }
 249
 250 #endif
 251
 252 __hidden enum ssl_conn_status __ustream_ssl_connect(struct ustream_ssl *us)
 253 {
 254         void *ssl = us->ssl;
 255         int r;
 256
 257         if (us->server)
 258                 r = SSL_accept(ssl);
 259         else
 260                 r = SSL_connect(ssl);
 261
 262         if (r == 1) {
 263 #ifndef CYASSL_OPENSSL_H_
 264                 ustream_ssl_verify_cert(us);
 265 #endif
 266                 return U_SSL_OK;
 267         }
 268
 269         r = SSL_get_error(ssl, r);
 270         if (r == SSL_ERROR_WANT_READ || r == SSL_ERROR_WANT_WRITE)
 271                 return U_SSL_PENDING;
 272
 273         ustream_ssl_error(us, r);
 274         return U_SSL_ERROR;
 275 }
 276
 277 __hidden int __ustream_ssl_write(struct ustream_ssl *us, const char *buf, int len)
 278 {
 279         void *ssl = us->ssl;
 280         int ret = SSL_write(ssl, buf, len);
 281
 282         if (ret < 0) {
 283                 int err = SSL_get_error(ssl, ret);
 284                 if (err == SSL_ERROR_WANT_WRITE)
 285                         return 0;
 286
 287                 ustream_ssl_error(us, err);
 288                 return -1;
 289         }
 290
 291         return ret;
 292 }
 293
 294 __hidden int __ustream_ssl_read(struct ustream_ssl *us, char *buf, int len)
 295 {
 296         int ret = SSL_read(us->ssl, buf, len);
 297
 298         if (ret < 0) {
 299                 ret = SSL_get_error(us->ssl, ret);
 300                 if (ret == SSL_ERROR_WANT_READ)
 301                         return U_SSL_PENDING;
 302
 303                 ustream_ssl_error(us, ret);
 304                 return U_SSL_ERROR;
 305         }
 306
 307         return ret;
 308 }
 309