1#include <string.h>
2#include <stdlib.h>
3#include <stdint.h>
4#include "common.h"
5#include "mbedtls/ssl.h"
6#if defined(MBEDTLS_SSL_PROTO_DTLS)
7#include "mbedtls/entropy.h"
8#include "mbedtls/ctr_drbg.h"
9#include "mbedtls/timing.h"
10#include "test/certs.h"
11
12#if defined(MBEDTLS_SSL_CLI_C) && \
13    defined(MBEDTLS_ENTROPY_C) && \
14    defined(MBEDTLS_CTR_DRBG_C) && \
15    defined(MBEDTLS_TIMING_C)
16static int initialized = 0;
17#if defined(MBEDTLS_X509_CRT_PARSE_C) && defined(MBEDTLS_PEM_PARSE_C)
18static mbedtls_x509_crt cacert;
19#endif
20
21const char *pers = "fuzz_dtlsclient";
22#endif
23#endif // MBEDTLS_SSL_PROTO_DTLS
24
25
26
27int LLVMFuzzerTestOneInput(const uint8_t *Data, size_t Size)
28{
29#if defined(MBEDTLS_SSL_PROTO_DTLS) && \
30    defined(MBEDTLS_SSL_CLI_C) && \
31    defined(MBEDTLS_ENTROPY_C) && \
32    defined(MBEDTLS_CTR_DRBG_C) && \
33    defined(MBEDTLS_TIMING_C)
34    int ret;
35    size_t len;
36    mbedtls_ssl_context ssl;
37    mbedtls_ssl_config conf;
38    mbedtls_ctr_drbg_context ctr_drbg;
39    mbedtls_entropy_context entropy;
40    mbedtls_timing_delay_context timer;
41    unsigned char buf[4096];
42    fuzzBufferOffset_t biomemfuzz;
43
44    if (initialized == 0) {
45#if defined(MBEDTLS_X509_CRT_PARSE_C) && defined(MBEDTLS_PEM_PARSE_C)
46        mbedtls_x509_crt_init(&cacert);
47        if (mbedtls_x509_crt_parse(&cacert, (const unsigned char *) mbedtls_test_cas_pem,
48                                   mbedtls_test_cas_pem_len) != 0) {
49            return 1;
50        }
51#endif
52        dummy_init();
53
54        initialized = 1;
55    }
56
57    mbedtls_ssl_init(&ssl);
58    mbedtls_ssl_config_init(&conf);
59    mbedtls_ctr_drbg_init(&ctr_drbg);
60    mbedtls_entropy_init(&entropy);
61
62#if defined(MBEDTLS_USE_PSA_CRYPTO)
63    psa_status_t status = psa_crypto_init();
64    if (status != PSA_SUCCESS) {
65        goto exit;
66    }
67#endif /* MBEDTLS_USE_PSA_CRYPTO */
68
69    srand(1);
70    if (mbedtls_ctr_drbg_seed(&ctr_drbg, dummy_entropy, &entropy,
71                              (const unsigned char *) pers, strlen(pers)) != 0) {
72        goto exit;
73    }
74
75    if (mbedtls_ssl_config_defaults(&conf,
76                                    MBEDTLS_SSL_IS_CLIENT,
77                                    MBEDTLS_SSL_TRANSPORT_DATAGRAM,
78                                    MBEDTLS_SSL_PRESET_DEFAULT) != 0) {
79        goto exit;
80    }
81
82#if defined(MBEDTLS_X509_CRT_PARSE_C) && defined(MBEDTLS_PEM_PARSE_C)
83    mbedtls_ssl_conf_ca_chain(&conf, &cacert, NULL);
84#endif
85    mbedtls_ssl_conf_authmode(&conf, MBEDTLS_SSL_VERIFY_NONE);
86    mbedtls_ssl_conf_rng(&conf, dummy_random, &ctr_drbg);
87
88    if (mbedtls_ssl_setup(&ssl, &conf) != 0) {
89        goto exit;
90    }
91
92    mbedtls_ssl_set_timer_cb(&ssl, &timer, mbedtls_timing_set_delay,
93                             mbedtls_timing_get_delay);
94
95#if defined(MBEDTLS_X509_CRT_PARSE_C) && defined(MBEDTLS_PEM_PARSE_C)
96    if (mbedtls_ssl_set_hostname(&ssl, "localhost") != 0) {
97        goto exit;
98    }
99#endif
100
101    biomemfuzz.Data = Data;
102    biomemfuzz.Size = Size;
103    biomemfuzz.Offset = 0;
104    mbedtls_ssl_set_bio(&ssl, &biomemfuzz, dummy_send, fuzz_recv, fuzz_recv_timeout);
105
106    ret = mbedtls_ssl_handshake(&ssl);
107    if (ret == 0) {
108        //keep reading data from server until the end
109        do {
110            len = sizeof(buf) - 1;
111            ret = mbedtls_ssl_read(&ssl, buf, len);
112
113            if (ret == MBEDTLS_ERR_SSL_WANT_READ) {
114                continue;
115            } else if (ret <= 0) {
116                //EOF or error
117                break;
118            }
119        } while (1);
120    }
121
122exit:
123    mbedtls_entropy_free(&entropy);
124    mbedtls_ctr_drbg_free(&ctr_drbg);
125    mbedtls_ssl_config_free(&conf);
126    mbedtls_ssl_free(&ssl);
127#if defined(MBEDTLS_USE_PSA_CRYPTO)
128    mbedtls_psa_crypto_free();
129#endif /* MBEDTLS_USE_PSA_CRYPTO */
130
131#else
132    (void) Data;
133    (void) Size;
134#endif
135    return 0;
136}
137