openssl_state_machine.c revision 6ff63662058d5891fc110f8b357a3604d7f7deb3
/* This is adapted from the OpenSSL state_machine demo */
/* ====================================================================
* Copyright (c) 2000 The OpenSSL Project. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
*
* 3. All advertising materials mentioning features or use of this
* software must display the following acknowledgment:
* "This product includes software developed by the OpenSSL Project
* for use in the OpenSSL Toolkit. (http://www.openssl.org/)"
*
* 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
* endorse or promote products derived from this software without
* prior written permission. For written permission, please contact
* openssl-core@openssl.org.
*
* 5. Products derived from this software may not be called "OpenSSL"
* nor may "OpenSSL" appear in their names without prior written
* permission of the OpenSSL Project.
*
* 6. Redistributions of any form whatsoever must retain the following
* acknowledgment:
* "This product includes software developed by the OpenSSL Project
* for use in the OpenSSL Toolkit (http://www.openssl.org/)"
*
* THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
* EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE OpenSSL PROJECT OR
* ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
* STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
* OF THE POSSIBILITY OF SUCH DAMAGE.
* ====================================================================
*
* This product includes cryptographic software written by Eric Young
* (eay@cryptsoft.com). This product includes software written by Tim
* Hudson (tjh@cryptsoft.com).
*
*/
/*
* Nuron, a leader in hardware encryption technology, generously
* sponsored the development of this demo by Ben Laurie.
*
* See http://www.nuron.com/.
*/
/*
* the aim of this demo is to provide a fully working state-machine
* style SSL implementation, i.e. one where the main loop acquires
* some data, then converts it from or to SSL by feeding it into the
* SSL state machine. It then does any I/O required by the state machine
* and loops.
*
* In order to keep things as simple as possible, this implementation
* listens on a TCP socket, which it expects to get an SSL connection
* on (for example, from s_client) and from then on writes decrypted
* data to stdout and encrypts anything arriving on stdin. Verbose
* commentary is written to stderr.
*
* This implementation acts as a server, but it can also be done for a client. */
#include "apr.h"
#include <openssl/ssl.h>
#include <assert.h>
#if APR_HAVE_UNISTD_H
#include <unistd.h>
#endif
#include <string.h>
#include <openssl/err.h>
#include "openssl_state_machine.h"
/* die_unless is intended to work like assert, except that it happens
always, even if NDEBUG is defined. Use assert as a stopgap. */
#define die_unless(x) assert(x)
struct SSLStateMachine
{
SSL_CTX *pCtx;
BIO *pbioRead;
BIO *pbioWrite;
SSL *pSSL;
};
void SSLStateMachine_init(void)
{
static int s_bInitDone;
if(s_bInitDone)
return;
SSL_library_init();
OpenSSL_add_ssl_algorithms();
SSL_load_error_strings();
ERR_load_crypto_strings();
s_bInitDone=1;
}
static void SSLStateMachine_print_error(SSLStateMachine *pMachine,
const char *szErr)
{
unsigned long l;
fprintf(stderr,"%s\n",szErr);
while((l=ERR_get_error()))
{
char buf[1024];
ERR_error_string_n(l,buf,sizeof buf);
fprintf(stderr,"Error %lx: %s\n",l,buf);
}
}
SSLStateMachine *SSLStateMachine_new(const char *szCertificateFile,
const char *szKeyFile)
{
SSLStateMachine *pMachine=malloc(sizeof *pMachine);
int n;
die_unless(pMachine);
pMachine->pCtx=SSL_CTX_new(SSLv23_server_method());
die_unless(pMachine->pCtx);
n=SSL_CTX_use_certificate_file(pMachine->pCtx,szCertificateFile,
SSL_FILETYPE_PEM);
die_unless(n > 0);
n=SSL_CTX_use_PrivateKey_file(pMachine->pCtx,szKeyFile,SSL_FILETYPE_PEM);
die_unless(n > 0);
pMachine->pSSL=SSL_new(pMachine->pCtx);
die_unless(pMachine->pSSL);
pMachine->pbioRead=BIO_new(BIO_s_mem());
pMachine->pbioWrite=BIO_new(BIO_s_mem());
SSL_set_bio(pMachine->pSSL,pMachine->pbioRead,pMachine->pbioWrite);
SSL_set_accept_state(pMachine->pSSL);
return pMachine;
}
void SSLStateMachine_read_inject(SSLStateMachine *pMachine,
const unsigned char *aucBuf,int nBuf)
{
int n=BIO_write(pMachine->pbioRead,aucBuf,nBuf);
/* If it turns out this assert fails, then buffer the data here
* and just feed it in in churn instead. Seems to me that it
* should be guaranteed to succeed, though.
*/
assert(n == nBuf);
fprintf(stderr,"%d bytes of encrypted data fed to state machine\n",n);
}
int SSLStateMachine_read_extract(SSLStateMachine *pMachine,
unsigned char *aucBuf,int nBuf)
{
int n;
if(!SSL_is_init_finished(pMachine->pSSL))
{
fprintf(stderr,"Doing SSL_accept\n");
n=SSL_accept(pMachine->pSSL);
if(n == 0)
fprintf(stderr,"SSL_accept returned zero\n");
if(n < 0)
{
int err;
if((err=SSL_get_error(pMachine->pSSL,n)) == SSL_ERROR_WANT_READ)
{
fprintf(stderr,"SSL_accept wants more data\n");
return 0;
}
SSLStateMachine_print_error(pMachine,"SSL_accept error");
exit(7);
}
return 0;
}
n=SSL_read(pMachine->pSSL,aucBuf,nBuf);
if(n < 0)
{
int err=SSL_get_error(pMachine->pSSL,n);
if(err == SSL_ERROR_WANT_READ)
{
fprintf(stderr,"SSL_read wants more data\n");
return 0;
}
SSLStateMachine_print_error(pMachine,"SSL_read error");
exit(8);
}
fprintf(stderr,"%d bytes of decrypted data read from state machine\n",n);
return n;
}
int SSLStateMachine_write_can_extract(SSLStateMachine *pMachine)
{
int n=BIO_pending(pMachine->pbioWrite);
if(n)
fprintf(stderr,"There is encrypted data available to write\n");
else
fprintf(stderr,"There is no encrypted data available to write\n");
return n;
}
int SSLStateMachine_write_extract(SSLStateMachine *pMachine,
unsigned char *aucBuf,int nBuf)
{
int n;
n=BIO_read(pMachine->pbioWrite,aucBuf,nBuf);
fprintf(stderr,"%d bytes of encrypted data read from state machine\n",n);
return n;
}
void SSLStateMachine_write_inject(SSLStateMachine *pMachine,
const unsigned char *aucBuf,int nBuf)
{
int n=SSL_write(pMachine->pSSL,aucBuf,nBuf);
if(n < 0)
{
if(ERR_peek_error() == ERR_PACK(ERR_LIB_SSL,SSL_F_SSL_WRITE,
SSL_R_PROTOCOL_IS_SHUTDOWN))
{
SSLStateMachine_print_error(pMachine,"SSL_write error (someone wrote after shutdown)");
return;
}
SSLStateMachine_print_error(pMachine,"SSL_write error");
}
/* If it turns out this assert fails, then buffer the data here
* and just feed it in in churn instead. Seems to me that it
* should be guaranteed to succeed, though.
*/
assert(n == nBuf);
fprintf(stderr,"%d bytes of unencrypted data fed to state machine\n",n);
}
void SSLStateMachine_write_close(SSLStateMachine *pMachine)
{
SSL_shutdown(pMachine->pSSL);
}