mbedtls/tests/fuzz/fuzz_server.c
2019-06-21 19:47:27 +02:00

241 lines
7.2 KiB
C

#include "mbedtls/ssl.h"
#include "mbedtls/entropy.h"
#include "mbedtls/ctr_drbg.h"
#include "mbedtls/certs.h"
#include "mbedtls/ssl_ticket.h"
#include <string.h>
#include <stdlib.h>
#include <stdbool.h>
#include <stdint.h>
const char *pers = "fuzz_server";
static bool initialized = 0;
#if defined(MBEDTLS_X509_CRT_PARSE_C)
static mbedtls_x509_crt srvcert;
static mbedtls_pk_context pkey;
#endif
const char *alpn_list[3];
#if defined(MBEDTLS_KEY_EXCHANGE__SOME__PSK_ENABLED)
const unsigned char psk[] = {
0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07,
0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f
};
const char psk_id[] = "Client_identity";
#endif
typedef struct fuzzBufferOffset
{
const uint8_t *Data;
size_t Size;
size_t Offset;
} fuzzBufferOffset_t;
static int dummy_send( void *ctx, const unsigned char *buf, size_t len )
{
//silence warning about unused parameter
(void) ctx;
(void) buf;
//pretends we wrote everything ok
return( len );
}
static int fuzz_recv( void *ctx, unsigned char *buf, size_t len )
{
//reads from the buffer from fuzzer
fuzzBufferOffset_t * biomemfuzz = (fuzzBufferOffset_t *) ctx;
if (biomemfuzz->Offset == biomemfuzz->Size) {
//EOF
return (0);
}
if (len + biomemfuzz->Offset > biomemfuzz->Size) {
//do not overflow
len = biomemfuzz->Size - biomemfuzz->Offset;
}
memcpy(buf, biomemfuzz->Data + biomemfuzz->Offset, len);
biomemfuzz->Offset += len;
return( len );
}
static int dummy_random( void *p_rng, unsigned char *output, size_t output_len )
{
int ret;
size_t i;
//use mbedtls_ctr_drbg_random to find bugs in it
ret = mbedtls_ctr_drbg_random(p_rng, output, output_len);
for (i=0; i<output_len; i++) {
//replace result with pseudo random
output[i] = (unsigned char) rand();
}
return( ret );
}
static int dummy_entropy( void *data, unsigned char *output, size_t len )
{
size_t i;
(void) data;
//use mbedtls_entropy_func to find bugs in it
//test performance impact of entropy
//ret = mbedtls_entropy_func(data, output, len);
for (i=0; i<len; i++) {
//replace result with pseudo random
output[i] = (unsigned char) rand();
}
return( 0 );
}
int LLVMFuzzerTestOneInput(const uint8_t *Data, size_t Size) {
int ret;
size_t len;
mbedtls_ssl_context ssl;
mbedtls_ssl_config conf;
mbedtls_ctr_drbg_context ctr_drbg;
mbedtls_entropy_context entropy;
#if defined(MBEDTLS_SSL_SESSION_TICKETS)
mbedtls_ssl_ticket_context ticket_ctx;
#endif
unsigned char buf[4096];
fuzzBufferOffset_t biomemfuzz;
uint8_t options;
//we take 1 byte as options input
if (Size < 1) {
return 0;
}
options = Data[Size - 1];
if (initialized == 0) {
#if defined(MBEDTLS_X509_CRT_PARSE_C)
mbedtls_x509_crt_init( &srvcert );
mbedtls_pk_init( &pkey );
if (mbedtls_x509_crt_parse( &srvcert, (const unsigned char *) mbedtls_test_srv_crt,
mbedtls_test_srv_crt_len ) != 0)
return 1;
if (mbedtls_x509_crt_parse( &srvcert, (const unsigned char *) mbedtls_test_cas_pem,
mbedtls_test_cas_pem_len ) != 0)
return 1;
if (mbedtls_pk_parse_key( &pkey, (const unsigned char *) mbedtls_test_srv_key,
mbedtls_test_srv_key_len, NULL, 0 ) != 0)
return 1;
#endif
alpn_list[0] = "HTTP";
alpn_list[1] = "fuzzalpn";
alpn_list[2] = NULL;
initialized = 1;
}
mbedtls_ssl_init( &ssl );
mbedtls_ssl_config_init( &conf );
mbedtls_ctr_drbg_init( &ctr_drbg );
mbedtls_entropy_init( &entropy );
#if defined(MBEDTLS_SSL_SESSION_TICKETS)
mbedtls_ssl_ticket_init( &ticket_ctx );
#endif
if( mbedtls_ctr_drbg_seed( &ctr_drbg, dummy_entropy, &entropy,
(const unsigned char *) pers, strlen( pers ) ) != 0 )
goto exit;
if( mbedtls_ssl_config_defaults( &conf,
MBEDTLS_SSL_IS_SERVER,
MBEDTLS_SSL_TRANSPORT_STREAM,
MBEDTLS_SSL_PRESET_DEFAULT ) != 0 )
goto exit;
srand(1);
mbedtls_ssl_conf_rng( &conf, dummy_random, &ctr_drbg );
#if defined(MBEDTLS_X509_CRT_PARSE_C)
mbedtls_ssl_conf_ca_chain( &conf, srvcert.next, NULL );
if( mbedtls_ssl_conf_own_cert( &conf, &srvcert, &pkey ) != 0 )
goto exit;
#endif
mbedtls_ssl_conf_cert_req_ca_list( &conf, (options & 0x1) ? MBEDTLS_SSL_CERT_REQ_CA_LIST_ENABLED : MBEDTLS_SSL_CERT_REQ_CA_LIST_DISABLED );
#if defined(MBEDTLS_SSL_ALPN)
if (options & 0x2) {
mbedtls_ssl_conf_alpn_protocols( &conf, alpn_list );
}
#endif
#if defined(MBEDTLS_SSL_SESSION_TICKETS)
if( options & 0x4 )
{
if( mbedtls_ssl_ticket_setup( &ticket_ctx,
dummy_random, &ctr_drbg,
MBEDTLS_CIPHER_AES_256_GCM,
86400 ) != 0 )
goto exit;
mbedtls_ssl_conf_session_tickets_cb( &conf,
mbedtls_ssl_ticket_write,
mbedtls_ssl_ticket_parse,
&ticket_ctx );
}
#endif
#if defined(MBEDTLS_SSL_TRUNCATED_HMAC)
mbedtls_ssl_conf_truncated_hmac( &conf, (options & 0x8) ? MBEDTLS_SSL_TRUNC_HMAC_ENABLED : MBEDTLS_SSL_TRUNC_HMAC_DISABLED);
#endif
#if defined(MBEDTLS_SSL_EXTENDED_MASTER_SECRET)
mbedtls_ssl_conf_extended_master_secret( &conf, (options & 0x10) ? MBEDTLS_SSL_EXTENDED_MS_DISABLED : MBEDTLS_SSL_EXTENDED_MS_ENABLED);
#endif
#if defined(MBEDTLS_SSL_ENCRYPT_THEN_MAC)
mbedtls_ssl_conf_encrypt_then_mac( &conf, (options & 0x20) ? MBEDTLS_SSL_ETM_ENABLED : MBEDTLS_SSL_ETM_DISABLED);
#endif
#if defined(MBEDTLS_KEY_EXCHANGE__SOME__PSK_ENABLED)
if (options & 0x40) {
mbedtls_ssl_conf_psk( &conf, psk, sizeof( psk ),
(const unsigned char *) psk_id, sizeof( psk_id ) - 1 );
}
#endif
#if defined(MBEDTLS_SSL_RENEGOTIATION)
mbedtls_ssl_conf_renegotiation( &conf, (options & 0x80) ? MBEDTLS_SSL_RENEGOTIATION_ENABLED : MBEDTLS_SSL_RENEGOTIATION_DISABLED );
#endif
if( mbedtls_ssl_setup( &ssl, &conf ) != 0 )
goto exit;
biomemfuzz.Data = Data;
biomemfuzz.Size = Size-1;
biomemfuzz.Offset = 0;
mbedtls_ssl_set_bio( &ssl, &biomemfuzz, dummy_send, fuzz_recv, NULL );
mbedtls_ssl_session_reset( &ssl );
ret = mbedtls_ssl_handshake( &ssl );
if( ret == 0 )
{
//keep reading data from server until the end
do
{
len = sizeof( buf ) - 1;
ret = mbedtls_ssl_read( &ssl, buf, len );
if( ret == MBEDTLS_ERR_SSL_WANT_READ )
continue;
else if( ret <= 0 )
//EOF or error
break;
}
while( 1 );
}
exit:
#if defined(MBEDTLS_SSL_SESSION_TICKETS)
mbedtls_ssl_ticket_free( &ticket_ctx );
#endif
mbedtls_entropy_free( &entropy );
mbedtls_ctr_drbg_free( &ctr_drbg );
mbedtls_ssl_config_free( &conf );
mbedtls_ssl_free( &ssl );
return 0;
}