1 files changed, 124 insertions, 0 deletions
diff --git a/programs/fuzz/fuzz_dtlsclient.c b/programs/fuzz/fuzz_dtlsclient.c
new file mode 100644
index 000000000..16f601470
--- /dev/null
+++ b/programs/fuzz/fuzz_dtlsclient.c
@@ -0,0 +1,124 @@
+#define MBEDTLS_ALLOW_PRIVATE_ACCESS
+
+#include <string.h>
+#include <stdlib.h>
+#include <stdint.h>
+#include "common.h"
+#include "mbedtls/ssl.h"
+#if defined(MBEDTLS_SSL_PROTO_DTLS)
+#include "mbedtls/entropy.h"
+#include "mbedtls/ctr_drbg.h"
+#include "mbedtls/timing.h"
+#include "test/certs.h"
+
+#if defined(MBEDTLS_SSL_CLI_C) && \
+    defined(MBEDTLS_ENTROPY_C) && \
+    defined(MBEDTLS_CTR_DRBG_C) && \
+    defined(MBEDTLS_TIMING_C)
+static int initialized = 0;
+#if defined(MBEDTLS_X509_CRT_PARSE_C) && defined(MBEDTLS_PEM_PARSE_C)
+static mbedtls_x509_crt cacert;
+#endif
+
+const char *pers = "fuzz_dtlsclient";
+#endif
+#endif // MBEDTLS_SSL_PROTO_DTLS
+
+
+
+int LLVMFuzzerTestOneInput(const uint8_t *Data, size_t Size) {
+#if defined(MBEDTLS_SSL_PROTO_DTLS) && \
+    defined(MBEDTLS_SSL_CLI_C) && \
+    defined(MBEDTLS_ENTROPY_C) && \
+    defined(MBEDTLS_CTR_DRBG_C) && \
+    defined(MBEDTLS_TIMING_C)
+    int ret;
+    size_t len;
+    mbedtls_ssl_context ssl;
+    mbedtls_ssl_config conf;
+    mbedtls_ctr_drbg_context ctr_drbg;
+    mbedtls_entropy_context entropy;
+    mbedtls_timing_delay_context timer;
+    unsigned char buf[4096];
+    fuzzBufferOffset_t biomemfuzz;
+
+    if (initialized == 0) {
+#if defined(MBEDTLS_X509_CRT_PARSE_C) && defined(MBEDTLS_PEM_PARSE_C)
+        mbedtls_x509_crt_init( &cacert );
+        if (mbedtls_x509_crt_parse( &cacert, (const unsigned char *) mbedtls_test_cas_pem,
+                                   mbedtls_test_cas_pem_len ) != 0)
+            return 1;
+#endif
+        dummy_init();
+
+        initialized = 1;
+    }
+
+    mbedtls_ssl_init( &ssl );
+    mbedtls_ssl_config_init( &conf );
+    mbedtls_ctr_drbg_init( &ctr_drbg );
+    mbedtls_entropy_init( &entropy );
+
+    srand(1);
+    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_CLIENT,
+                                    MBEDTLS_SSL_TRANSPORT_DATAGRAM,
+                                    MBEDTLS_SSL_PRESET_DEFAULT ) != 0 )
+        goto exit;
+
+#if defined(MBEDTLS_X509_CRT_PARSE_C) && defined(MBEDTLS_PEM_PARSE_C)
+    mbedtls_ssl_conf_ca_chain( &conf, &cacert, NULL );
+#endif
+    mbedtls_ssl_conf_authmode( &conf, MBEDTLS_SSL_VERIFY_NONE );
+    mbedtls_ssl_conf_rng( &conf, dummy_random, &ctr_drbg );
+
+    if( mbedtls_ssl_setup( &ssl, &conf ) != 0 )
+        goto exit;
+
+    mbedtls_ssl_set_timer_cb( &ssl, &timer, mbedtls_timing_set_delay,
+                             mbedtls_timing_get_delay );
+
+#if defined(MBEDTLS_X509_CRT_PARSE_C) && defined(MBEDTLS_PEM_PARSE_C)
+    if( mbedtls_ssl_set_hostname( &ssl, "localhost" ) != 0 )
+        goto exit;
+#endif
+
+    biomemfuzz.Data = Data;
+    biomemfuzz.Size = Size;
+    biomemfuzz.Offset = 0;
+    mbedtls_ssl_set_bio( &ssl, &biomemfuzz, dummy_send, fuzz_recv, fuzz_recv_timeout );
+
+    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:
+    mbedtls_entropy_free( &entropy );
+    mbedtls_ctr_drbg_free( &ctr_drbg );
+    mbedtls_ssl_config_free( &conf );
+    mbedtls_ssl_free( &ssl );
+
+#else
+    (void) Data;
+    (void) Size;
+#endif
+    return 0;
+}