crypto/openssl/demos/state_machine/state_machine.c

   1 /* ====================================================================
   2  * Copyright (c) 2000 The OpenSSL Project.  All rights reserved.
   3  *
   4  * Redistribution and use in source and binary forms, with or without
   5  * modification, are permitted provided that the following conditions
   6  * are met:
   7  *
   8  * 1. Redistributions of source code must retain the above copyright
   9  *    notice, this list of conditions and the following disclaimer.
  10  *
  11  * 2. Redistributions in binary form must reproduce the above copyright
  12  *    notice, this list of conditions and the following disclaimer in
  13  *    the documentation and/or other materials provided with the
  14  *    distribution.
  15  *
  16  * 3. All advertising materials mentioning features or use of this
  17  *    software must display the following acknowledgment:
  18  *    "This product includes software developed by the OpenSSL Project
  19  *    for use in the OpenSSL Toolkit. (http://www.openssl.org/)"
  20  *
  21  * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
  22  *    endorse or promote products derived from this software without
  23  *    prior written permission. For written permission, please contact
  24  *    openssl-core@openssl.org.
  25  *
  26  * 5. Products derived from this software may not be called "OpenSSL"
  27  *    nor may "OpenSSL" appear in their names without prior written
  28  *    permission of the OpenSSL Project.
  29  *
  30  * 6. Redistributions of any form whatsoever must retain the following
  31  *    acknowledgment:
  32  *    "This product includes software developed by the OpenSSL Project
  33  *    for use in the OpenSSL Toolkit (http://www.openssl.org/)"
  34  *
  35  * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
  36  * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  37  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  38  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE OpenSSL PROJECT OR
  39  * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  40  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  41  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
  42  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  43  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
  44  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
  45  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
  46  * OF THE POSSIBILITY OF SUCH DAMAGE.
  47  * ====================================================================
  48  *
  49  * This product includes cryptographic software written by Eric Young
  50  * (eay@cryptsoft.com).  This product includes software written by Tim
  51  * Hudson (tjh@cryptsoft.com).
  52  *
  53  */
  54
  55 /*
  56  * Nuron, a leader in hardware encryption technology, generously
  57  * sponsored the development of this demo by Ben Laurie.
  58  *
  59  * See http://www.nuron.com/.
  60  */
  61
  62 /*
  63  * the aim of this demo is to provide a fully working state-machine
  64  * style SSL implementation, i.e. one where the main loop acquires
  65  * some data, then converts it from or to SSL by feeding it into the
  66  * SSL state machine. It then does any I/O required by the state machine
  67  * and loops.
  68  *
  69  * In order to keep things as simple as possible, this implementation
  70  * listens on a TCP socket, which it expects to get an SSL connection
  71  * on (for example, from s_client) and from then on writes decrypted
  72  * data to stdout and encrypts anything arriving on stdin. Verbose
  73  * commentary is written to stderr.
  74  *
  75  * This implementation acts as a server, but it can also be done for a client.  */
  76
  77 #include <openssl/ssl.h>
  78 #include <assert.h>
  79 #include <unistd.h>
  80 #include <string.h>
  81 #include <openssl/err.h>
  82 #include <sys/types.h>
  83 #include <sys/socket.h>
  84 #include <netinet/in.h>
  85
  86 /* die_unless is intended to work like assert, except that it happens
  87    always, even if NDEBUG is defined. Use assert as a stopgap. */
  88
  89 #define die_unless(x)   assert(x)
  90
  91 typedef struct
  92     {
  93     SSL_CTX *pCtx;
  94     BIO *pbioRead;
  95     BIO *pbioWrite;
  96     SSL *pSSL;
  97     } SSLStateMachine;
  98
  99 void SSLStateMachine_print_error(SSLStateMachine *pMachine,const char *szErr)
 100     {
 101     unsigned long l;
 102
 103     fprintf(stderr,"%s\n",szErr);
 104     while((l=ERR_get_error()))
 105         {
 106         char buf[1024];
 107
 108         ERR_error_string_n(l,buf,sizeof buf);
 109         fprintf(stderr,"Error %lx: %s\n",l,buf);
 110         }
 111     }
 112
 113 SSLStateMachine *SSLStateMachine_new(const char *szCertificateFile,
 114                                      const char *szKeyFile)
 115     {
 116     SSLStateMachine *pMachine=malloc(sizeof *pMachine);
 117     int n;
 118
 119     die_unless(pMachine);
 120
 121     pMachine->pCtx=SSL_CTX_new(SSLv23_server_method());
 122     die_unless(pMachine->pCtx);
 123
 124     n=SSL_CTX_use_certificate_file(pMachine->pCtx,szCertificateFile,
 125                                    SSL_FILETYPE_PEM);
 126     die_unless(n > 0);
 127
 128     n=SSL_CTX_use_PrivateKey_file(pMachine->pCtx,szKeyFile,SSL_FILETYPE_PEM);
 129     die_unless(n > 0);
 130
 131     pMachine->pSSL=SSL_new(pMachine->pCtx);
 132     die_unless(pMachine->pSSL);
 133
 134     pMachine->pbioRead=BIO_new(BIO_s_mem());
 135
 136     pMachine->pbioWrite=BIO_new(BIO_s_mem());
 137
 138     SSL_set_bio(pMachine->pSSL,pMachine->pbioRead,pMachine->pbioWrite);
 139
 140     SSL_set_accept_state(pMachine->pSSL);
 141
 142     return pMachine;
 143     }
 144
 145 void SSLStateMachine_read_inject(SSLStateMachine *pMachine,
 146                                  const unsigned char *aucBuf,int nBuf)
 147     {
 148     int n=BIO_write(pMachine->pbioRead,aucBuf,nBuf);
 149     /* If it turns out this assert fails, then buffer the data here
 150      * and just feed it in in churn instead. Seems to me that it
 151      * should be guaranteed to succeed, though.
 152      */
 153     assert(n == nBuf);
 154     fprintf(stderr,"%d bytes of encrypted data fed to state machine\n",n);
 155     }
 156
 157 int SSLStateMachine_read_extract(SSLStateMachine *pMachine,
 158                                  unsigned char *aucBuf,int nBuf)
 159     {
 160     int n;
 161
 162     if(!SSL_is_init_finished(pMachine->pSSL))
 163         {
 164         fprintf(stderr,"Doing SSL_accept\n");
 165         n=SSL_accept(pMachine->pSSL);
 166         if(n == 0)
 167             fprintf(stderr,"SSL_accept returned zero\n");
 168         if(n < 0)
 169             {
 170             int err;
 171
 172             if((err=SSL_get_error(pMachine->pSSL,n)) == SSL_ERROR_WANT_READ)
 173                 {
 174                 fprintf(stderr,"SSL_accept wants more data\n");
 175                 return 0;
 176                 }
 177
 178             SSLStateMachine_print_error(pMachine,"SSL_accept error");
 179             exit(7);
 180             }
 181         return 0;
 182         }
 183
 184     n=SSL_read(pMachine->pSSL,aucBuf,nBuf);
 185     if(n < 0)
 186         {
 187         int err=SSL_get_error(pMachine->pSSL,n);
 188
 189         if(err == SSL_ERROR_WANT_READ)
 190             {
 191             fprintf(stderr,"SSL_read wants more data\n");
 192             return 0;
 193             }
 194
 195         SSLStateMachine_print_error(pMachine,"SSL_read error");
 196         exit(8);
 197         }
 198
 199     fprintf(stderr,"%d bytes of decrypted data read from state machine\n",n);
 200     return n;
 201     }
 202
 203 int SSLStateMachine_write_can_extract(SSLStateMachine *pMachine)
 204     {
 205     int n=BIO_pending(pMachine->pbioWrite);
 206     if(n)
 207         fprintf(stderr,"There is encrypted data available to write\n");
 208     else
 209         fprintf(stderr,"There is no encrypted data available to write\n");
 210
 211     return n;
 212     }
 213
 214 int SSLStateMachine_write_extract(SSLStateMachine *pMachine,
 215                                   unsigned char *aucBuf,int nBuf)
 216     {
 217     int n;
 218
 219     n=BIO_read(pMachine->pbioWrite,aucBuf,nBuf);
 220     fprintf(stderr,"%d bytes of encrypted data read from state machine\n",n);
 221     return n;
 222     }
 223
 224 void SSLStateMachine_write_inject(SSLStateMachine *pMachine,
 225                                   const unsigned char *aucBuf,int nBuf)
 226     {
 227     int n=SSL_write(pMachine->pSSL,aucBuf,nBuf);
 228     /* If it turns out this assert fails, then buffer the data here
 229      * and just feed it in in churn instead. Seems to me that it
 230      * should be guaranteed to succeed, though.
 231      */
 232     assert(n == nBuf);
 233     fprintf(stderr,"%d bytes of unencrypted data fed to state machine\n",n);
 234     }
 235
 236 int OpenSocket(int nPort)
 237     {
 238     int nSocket;
 239     struct sockaddr_in saServer;
 240     struct sockaddr_in saClient;
 241     int one=1;
 242     int nSize;
 243     int nFD;
 244     int nLen;
 245
 246     nSocket=socket(AF_INET,SOCK_STREAM,IPPROTO_TCP);
 247     if(nSocket < 0)
 248         {
 249         perror("socket");
 250         exit(1);
 251         }
 252
 253     if(setsockopt(nSocket,SOL_SOCKET,SO_REUSEADDR,(char *)&one,sizeof one) < 0)
 254         {
 255         perror("setsockopt");
 256         exit(2);
 257         }
 258
 259     memset(&saServer,0,sizeof saServer);
 260     saServer.sin_family=AF_INET;
 261     saServer.sin_port=htons(nPort);
 262     nSize=sizeof saServer;
 263     if(bind(nSocket,(struct sockaddr *)&saServer,nSize) < 0)
 264         {
 265         perror("bind");
 266         exit(3);
 267         }
 268
 269     if(listen(nSocket,512) < 0)
 270         {
 271         perror("listen");
 272         exit(4);
 273         }
 274
 275     nLen=sizeof saClient;
 276     nFD=accept(nSocket,(struct sockaddr *)&saClient,&nLen);
 277     if(nFD < 0)
 278         {
 279         perror("accept");
 280         exit(5);
 281         }
 282
 283     fprintf(stderr,"Incoming accepted on port %d\n",nPort);
 284
 285     return nFD;
 286     }
 287
 288 int main(int argc,char **argv)
 289     {
 290     SSLStateMachine *pMachine;
 291     int nPort;
 292     int nFD;
 293     const char *szCertificateFile;
 294     const char *szKeyFile;
 295     char rbuf[1];
 296     int nrbuf=0;
 297
 298     if(argc != 4)
 299         {
 300         fprintf(stderr,"%s <port> <certificate file> <key file>\n",argv[0]);
 301         exit(6);
 302         }
 303
 304     nPort=atoi(argv[1]);
 305     szCertificateFile=argv[2];
 306     szKeyFile=argv[3];
 307
 308     SSL_library_init();
 309     OpenSSL_add_ssl_algorithms();
 310     SSL_load_error_strings();
 311     ERR_load_crypto_strings();
 312
 313     nFD=OpenSocket(nPort);
 314
 315     pMachine=SSLStateMachine_new(szCertificateFile,szKeyFile);
 316
 317     for( ; ; )
 318         {
 319         fd_set rfds,wfds;
 320         unsigned char buf[1024];
 321         int n;
 322
 323         FD_ZERO(&rfds);
 324         FD_ZERO(&wfds);
 325
 326         /* Select socket for input */
 327         FD_SET(nFD,&rfds);
 328
 329         /* check whether there's decrypted data */
 330         if(!nrbuf)
 331             nrbuf=SSLStateMachine_read_extract(pMachine,rbuf,1);
 332
 333         /* if there's decrypted data, check whether we can write it */
 334         if(nrbuf)
 335             FD_SET(1,&wfds);
 336
 337         /* Select socket for output */
 338         if(SSLStateMachine_write_can_extract(pMachine))
 339             FD_SET(nFD,&wfds);
 340
 341         /* Select stdin for input */
 342         FD_SET(0,&rfds);
 343
 344         /* Wait for something to do something */
 345         n=select(nFD+1,&rfds,&wfds,NULL,NULL);
 346         assert(n > 0);
 347
 348         /* Socket is ready for input */
 349         if(FD_ISSET(nFD,&rfds))
 350             {
 351             n=read(nFD,buf,sizeof buf);
 352             if(n == 0)
 353                 {
 354                 fprintf(stderr,"Got EOF on socket\n");
 355                 exit(0);
 356                 }
 357             assert(n > 0);
 358
 359             SSLStateMachine_read_inject(pMachine,buf,n);
 360             }
 361
 362         /* stdout is ready for output (and hence we have some to send it) */
 363         if(FD_ISSET(1,&wfds))
 364             {
 365             assert(nrbuf == 1);
 366             buf[0]=rbuf[0];
 367             nrbuf=0;
 368
 369             n=SSLStateMachine_read_extract(pMachine,buf+1,sizeof buf-1);
 370             if(n < 0)
 371                 {
 372                 SSLStateMachine_print_error(pMachine,"read extract failed");
 373                 break;
 374                 }
 375             assert(n >= 0);
 376             ++n;
 377             if(n > 0) /* FIXME: has to be true now */
 378                 {
 379                 int w;
 380
 381                 w=write(1,buf,n);
 382                 /* FIXME: we should push back any unwritten data */
 383                 assert(w == n);
 384                 }
 385             }
 386
 387         /* Socket is ready for output (and therefore we have output to send) */
 388         if(FD_ISSET(nFD,&wfds))
 389             {
 390             int w;
 391
 392             n=SSLStateMachine_write_extract(pMachine,buf,sizeof buf);
 393             assert(n > 0);
 394
 395             w=write(nFD,buf,n);
 396             /* FIXME: we should push back any unwritten data */
 397             assert(w == n);
 398             }
 399
 400         /* Stdin is ready for input */
 401         if(FD_ISSET(0,&rfds))
 402             {
 403             n=read(0,buf,sizeof buf);
 404             if(n == 0)
 405                 {
 406                 fprintf(stderr,"Got EOF on stdin\n");
 407                 exit(0);
 408                 }
 409             assert(n > 0);
 410
 411             SSLStateMachine_write_inject(pMachine,buf,n);
 412             }
 413         }
 414     /* not reached */
 415     return 0;
 416     }