_ Git - BearSSL/blob - samples/server_basic.c

   1 /*
   2  * Copyright (c) 2016 Thomas Pornin <pornin@bolet.org>
   3  *
   4  * Permission is hereby granted, free of charge, to any person obtaining
   5  * a copy of this software and associated documentation files (the
   6  * "Software"), to deal in the Software without restriction, including
   7  * without limitation the rights to use, copy, modify, merge, publish,
   8  * distribute, sublicense, and/or sell copies of the Software, and to
   9  * permit persons to whom the Software is furnished to do so, subject to
  10  * the following conditions:
  11  *
  12  * The above copyright notice and this permission notice shall be
  13  * included in all copies or substantial portions of the Software.
  14  *
  15  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  16  * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  17  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  18  * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
  19  * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
  20  * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
  21  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  22  * SOFTWARE.
  23  */
  24
  25 #include <stdio.h>
  26 #include <stdlib.h>
  27 #include <string.h>
  28 #include <stdint.h>
  29 #include <errno.h>
  30
  31 #include <sys/types.h>
  32 #include <sys/socket.h>
  33 #include <netdb.h>
  34 #include <netinet/in.h>
  35 #include <arpa/inet.h>
  36 #include <unistd.h>
  37
  38 #include "bearssl.h"
  39
  40 /*
  41  * This sample code can use three possible certificate chains:
  42  * -- A full-RSA chain (server key is RSA, certificates are signed with RSA)
  43  * -- A full-EC chain (server key is EC, certificates are signed with ECDSA)
  44  * -- A mixed chain (server key is EC, certificates are signed with RSA)
  45  *
  46  * The macros below define which chain is selected. This impacts the list
  47  * of supported cipher suites.
  48  */
  49
  50 #if !(SERVER_RSA || SERVER_EC || SERVER_MIXED)
  51 #define SERVER_RSA     1
  52 #define SERVER_EC      0
  53 #define SERVER_MIXED   0
  54 #endif
  55
  56 #if SERVER_RSA
  57 #include "chain-rsa.h"
  58 #include "key-rsa.h"
  59 #define SKEY   RSA
  60 #elif SERVER_EC
  61 #include "chain-ec.h"
  62 #include "key-ec.h"
  63 #define SKEY   EC
  64 #elif SERVER_MIXED
  65 #include "chain-ec+rsa.h"
  66 #include "key-ec.h"
  67 #define SKEY   EC
  68 #else
  69 #error Must use one of RSA, EC or MIXED chains.
  70 #endif
  71
  72 /*
  73  * Create a server socket bound to the specified host and port. If 'host'
  74  * is NULL, this will bind "generically" (all addresses).
  75  *
  76  * Returned value is the server socket descriptor, or -1 on error.
  77  */
  78 static int
  79 host_bind(const char *host, const char *port)
  80 {
  81         struct addrinfo hints, *si, *p;
  82         int fd;
  83         int err;
  84
  85         memset(&hints, 0, sizeof hints);
  86         hints.ai_family = PF_UNSPEC;
  87         hints.ai_socktype = SOCK_STREAM;
  88         err = getaddrinfo(host, port, &hints, &si);
  89         if (err != 0) {
  90                 fprintf(stderr, "ERROR: getaddrinfo(): %s\n",
  91                         gai_strerror(err));
  92                 return -1;
  93         }
  94         fd = -1;
  95         for (p = si; p != NULL; p = p->ai_next) {
  96                 struct sockaddr *sa;
  97                 struct sockaddr_in sa4;
  98                 struct sockaddr_in6 sa6;
  99                 size_t sa_len;
 100                 void *addr;
 101                 char tmp[INET6_ADDRSTRLEN + 50];
 102                 int opt;
 103
 104                 sa = (struct sockaddr *)p->ai_addr;
 105                 if (sa->sa_family == AF_INET) {
 106                         sa4 = *(struct sockaddr_in *)sa;
 107                         sa = (struct sockaddr *)&sa4;
 108                         sa_len = sizeof sa4;
 109                         addr = &sa4.sin_addr;
 110                         if (host == NULL) {
 111                                 sa4.sin_addr.s_addr = INADDR_ANY;
 112                         }
 113                 } else if (sa->sa_family == AF_INET6) {
 114                         sa6 = *(struct sockaddr_in6 *)sa;
 115                         sa = (struct sockaddr *)&sa6;
 116                         sa_len = sizeof sa6;
 117                         addr = &sa6.sin6_addr;
 118                         if (host == NULL) {
 119                                 sa6.sin6_addr = in6addr_any;
 120                         }
 121                 } else {
 122                         addr = NULL;
 123                         sa_len = p->ai_addrlen;
 124                 }
 125                 if (addr != NULL) {
 126                         inet_ntop(p->ai_family, addr, tmp, sizeof tmp);
 127                 } else {
 128                         sprintf(tmp, "<unknown family: %d>",
 129                                 (int)sa->sa_family);
 130                 }
 131                 fprintf(stderr, "binding to: %s\n", tmp);
 132                 fd = socket(p->ai_family, p->ai_socktype, p->ai_protocol);
 133                 if (fd < 0) {
 134                         perror("socket()");
 135                         continue;
 136                 }
 137                 opt = 1;
 138                 setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &opt, sizeof opt);
 139                 opt = 0;
 140                 setsockopt(fd, IPPROTO_IPV6, IPV6_V6ONLY, &opt, sizeof opt);
 141                 if (bind(fd, sa, sa_len) < 0) {
 142                         perror("bind()");
 143                         close(fd);
 144                         continue;
 145                 }
 146                 break;
 147         }
 148         if (p == NULL) {
 149                 freeaddrinfo(si);
 150                 fprintf(stderr, "ERROR: failed to bind\n");
 151                 return -1;
 152         }
 153         freeaddrinfo(si);
 154         if (listen(fd, 5) < 0) {
 155                 perror("listen()");
 156                 close(fd);
 157                 return -1;
 158         }
 159         fprintf(stderr, "bound.\n");
 160         return fd;
 161 }
 162
 163 /*
 164  * Accept a single client on the provided server socket. This is blocking.
 165  * On error, this returns -1.
 166  */
 167 static int
 168 accept_client(int server_fd)
 169 {
 170         int fd;
 171         struct sockaddr sa;
 172         socklen_t sa_len;
 173         char tmp[INET6_ADDRSTRLEN + 50];
 174         const char *name;
 175
 176         sa_len = sizeof sa;
 177         fd = accept(server_fd, &sa, &sa_len);
 178         if (fd < 0) {
 179                 perror("accept()");
 180                 return -1;
 181         }
 182         name = NULL;
 183         switch (sa.sa_family) {
 184         case AF_INET:
 185                 name = inet_ntop(AF_INET,
 186                         &((struct sockaddr_in *)&sa)->sin_addr,
 187                         tmp, sizeof tmp);
 188                 break;
 189         case AF_INET6:
 190                 name = inet_ntop(AF_INET,
 191                         &((struct sockaddr_in *)&sa)->sin_addr,
 192                         tmp, sizeof tmp);
 193                 break;
 194         }
 195         if (name == NULL) {
 196                 sprintf(tmp, "<unknown: %lu>", (unsigned long)sa.sa_family);
 197                 name = tmp;
 198         }
 199         fprintf(stderr, "accepting connection from: %s\n", name);
 200         return fd;
 201 }
 202
 203 /*
 204  * Low-level data read callback for the simplified SSL I/O API.
 205  */
 206 static int
 207 sock_read(void *ctx, unsigned char *buf, size_t len)
 208 {
 209         for (;;) {
 210                 ssize_t rlen;
 211
 212                 rlen = read(*(int *)ctx, buf, len);
 213                 if (rlen <= 0) {
 214                         if (rlen < 0 && errno == EINTR) {
 215                                 continue;
 216                         }
 217                         return -1;
 218                 }
 219                 return (int)rlen;
 220         }
 221 }
 222
 223 /*
 224  * Low-level data write callback for the simplified SSL I/O API.
 225  */
 226 static int
 227 sock_write(void *ctx, const unsigned char *buf, size_t len)
 228 {
 229         for (;;) {
 230                 ssize_t wlen;
 231
 232                 wlen = write(*(int *)ctx, buf, len);
 233                 if (wlen <= 0) {
 234                         if (wlen < 0 && errno == EINTR) {
 235                                 continue;
 236                         }
 237                         return -1;
 238                 }
 239                 return (int)wlen;
 240         }
 241 }
 242
 243 /*
 244  * Sample HTTP response to send.
 245  */
 246 static const char *HTTP_RES =
 247         "HTTP/1.0 200 OK\r\n"
 248         "Content-Length: 46\r\n"
 249         "Connection: close\r\n"
 250         "Content-Type: text/html; charset=iso-8859-1\r\n"
 251         "\r\n"
 252         "<html>\r\n"
 253         "<body>\r\n"
 254         "<p>Test!</p>\r\n"
 255         "</body>\r\n"
 256         "</html>\r\n";
 257
 258 /*
 259  * Main program: this is a simple program that expects 1 argument: a
 260  * port number. This will start a simple network server on that port,
 261  * that expects incoming SSL clients. It handles only one client at a
 262  * time (handling several would require threads, sub-processes, or
 263  * multiplexing with select()/poll(), all of which being possible).
 264  *
 265  * For each client, the server will wait for two successive newline
 266  * characters (ignoring CR characters, so CR+LF is accepted), then
 267  * produce a sample static HTTP response. This is very crude, but
 268  * sufficient for explanatory purposes.
 269  */
 270 int
 271 main(int argc, char *argv[])
 272 {
 273         const char *port;
 274         int fd;
 275
 276         if (argc != 2) {
 277                 return EXIT_FAILURE;
 278         }
 279         port = argv[1];
 280
 281         /*
 282          * Open the server socket.
 283          */
 284         fd = host_bind(NULL, port);
 285         if (fd < 0) {
 286                 return EXIT_FAILURE;
 287         }
 288
 289         /*
 290          * Process each client, one at a time.
 291          */
 292         for (;;) {
 293                 int cfd;
 294                 br_ssl_server_context sc;
 295                 unsigned char iobuf[BR_SSL_BUFSIZE_BIDI];
 296                 br_sslio_context ioc;
 297                 int lcwn, err;
 298
 299                 cfd = accept_client(fd);
 300                 if (cfd < 0) {
 301                         return EXIT_FAILURE;
 302                 }
 303
 304                 /*
 305                  * Initialise the context with the cipher suites and
 306                  * algorithms. This depends on the server key type
 307                  * (and, for EC keys, the signature algorithm used by
 308                  * the CA to sign the server's certificate).
 309                  *
 310                  * Depending on the defined macros, we may select one of
 311                  * the "minimal" profiles. Key exchange algorithm depends
 312                  * on the key type:
 313                  *   RSA key: RSA or ECDHE_RSA
 314                  *   EC key, cert signed with ECDSA: ECDH_ECDSA or ECDHE_ECDSA
 315                  *   EC key, cert signed with RSA: ECDH_RSA or ECDHE_ECDSA
 316                  */
 317 #if SERVER_RSA
 318 #if SERVER_PROFILE_MIN_FS
 319                 br_ssl_server_init_mine2g(&sc, CHAIN, CHAIN_LEN, &SKEY);
 320 #elif SERVER_PROFILE_MIN_NOFS
 321                 br_ssl_server_init_minr2g(&sc, CHAIN, CHAIN_LEN, &SKEY);
 322 #else
 323                 br_ssl_server_init_full_rsa(&sc, CHAIN, CHAIN_LEN, &SKEY);
 324 #endif
 325 #elif SERVER_EC
 326 #if SERVER_PROFILE_MIN_FS
 327                 br_ssl_server_init_minf2g(&sc, CHAIN, CHAIN_LEN, &SKEY);
 328 #elif SERVER_PROFILE_MIN_NOFS
 329                 br_ssl_server_init_minv2g(&sc, CHAIN, CHAIN_LEN, &SKEY);
 330 #else
 331                 br_ssl_server_init_full_ec(&sc, CHAIN, CHAIN_LEN,
 332                         BR_KEYTYPE_EC, &SKEY);
 333 #endif
 334 #else /* SERVER_MIXED */
 335 #if SERVER_PROFILE_MIN_FS
 336                 br_ssl_server_init_minf2g(&sc, CHAIN, CHAIN_LEN, &SKEY);
 337 #elif SERVER_PROFILE_MIN_NOFS
 338                 br_ssl_server_init_minu2g(&sc, CHAIN, CHAIN_LEN, &SKEY);
 339 #else
 340                 br_ssl_server_init_full_ec(&sc, CHAIN, CHAIN_LEN,
 341                         BR_KEYTYPE_RSA, &SKEY);
 342 #endif
 343 #endif
 344                 /*
 345                  * Set the I/O buffer to the provided array. We
 346                  * allocated a buffer large enough for full-duplex
 347                  * behaviour with all allowed sizes of SSL records,
 348                  * hence we set the last argument to 1 (which means
 349                  * "split the buffer into separate input and output
 350                  * areas").
 351                  */
 352                 br_ssl_engine_set_buffer(&sc.eng, iobuf, sizeof iobuf, 1);
 353
 354                 /*
 355                  * Reset the server context, for a new handshake.
 356                  */
 357                 br_ssl_server_reset(&sc);
 358
 359                 /*
 360                  * Initialise the simplified I/O wrapper context.
 361                  */
 362                 br_sslio_init(&ioc, &sc.eng, sock_read, &cfd, sock_write, &cfd);
 363
 364                 /*
 365                  * Read bytes until two successive LF (or CR+LF) are received.
 366                  */
 367                 lcwn = 0;
 368                 for (;;) {
 369                         unsigned char x;
 370
 371                         if (br_sslio_read(&ioc, &x, 1) < 0) {
 372                                 goto client_drop;
 373                         }
 374                         if (x == 0x0D) {
 375                                 continue;
 376                         }
 377                         if (x == 0x0A) {
 378                                 if (lcwn) {
 379                                         break;
 380                                 }
 381                                 lcwn = 1;
 382                         } else {
 383                                 lcwn = 0;
 384                         }
 385                 }
 386
 387                 /*
 388                  * Write a response and close the connection.
 389                  */
 390                 br_sslio_write_all(&ioc, HTTP_RES, strlen(HTTP_RES));
 391                 br_sslio_close(&ioc);
 392
 393         client_drop:
 394                 err = br_ssl_engine_last_error(&sc.eng);
 395                 if (err == 0) {
 396                         fprintf(stderr, "SSL closed (correctly).\n");
 397                 } else {
 398                         fprintf(stderr, "SSL error: %d\n", err);
 399                 }
 400                 close(cfd);
 401         }
 402 }