1 #include "common.h"
2 #include <limits.h>
3 #include <stdio.h>
4 #include <string.h>
5 #include <stdlib.h>
6 #include "mbedtls/ctr_drbg.h"
7
8 #if defined(MBEDTLS_PLATFORM_TIME_ALT)
dummy_constant_time(mbedtls_time_t * time)9 mbedtls_time_t dummy_constant_time(mbedtls_time_t *time)
10 {
11 (void) time;
12 return 0x5af2a056;
13 }
14 #endif
15
dummy_init(void)16 void dummy_init(void)
17 {
18 #if defined(MBEDTLS_PLATFORM_TIME_ALT)
19 mbedtls_platform_set_time(dummy_constant_time);
20 #else
21 fprintf(stderr, "Warning: fuzzing without constant time\n");
22 #endif
23 }
24
dummy_send(void * ctx,const unsigned char * buf,size_t len)25 int dummy_send(void *ctx, const unsigned char *buf, size_t len)
26 {
27 //silence warning about unused parameter
28 (void) ctx;
29 (void) buf;
30
31 //pretends we wrote everything ok
32 if (len > INT_MAX) {
33 return -1;
34 }
35 return (int) len;
36 }
37
fuzz_recv(void * ctx,unsigned char * buf,size_t len)38 int fuzz_recv(void *ctx, unsigned char *buf, size_t len)
39 {
40 //reads from the buffer from fuzzer
41 fuzzBufferOffset_t *biomemfuzz = (fuzzBufferOffset_t *) ctx;
42
43 if (biomemfuzz->Offset == biomemfuzz->Size) {
44 //EOF
45 return 0;
46 }
47 if (len > INT_MAX) {
48 return -1;
49 }
50 if (len + biomemfuzz->Offset > biomemfuzz->Size) {
51 //do not overflow
52 len = biomemfuzz->Size - biomemfuzz->Offset;
53 }
54 memcpy(buf, biomemfuzz->Data + biomemfuzz->Offset, len);
55 biomemfuzz->Offset += len;
56 return (int) len;
57 }
58
dummy_random(void * p_rng,unsigned char * output,size_t output_len)59 int dummy_random(void *p_rng, unsigned char *output, size_t output_len)
60 {
61 int ret;
62 size_t i;
63
64 #if defined(MBEDTLS_CTR_DRBG_C)
65 //use mbedtls_ctr_drbg_random to find bugs in it
66 ret = mbedtls_ctr_drbg_random(p_rng, output, output_len);
67 #else
68 (void) p_rng;
69 ret = 0;
70 #endif
71 for (i = 0; i < output_len; i++) {
72 //replace result with pseudo random
73 output[i] = (unsigned char) rand();
74 }
75 return ret;
76 }
77
dummy_entropy(void * data,unsigned char * output,size_t len)78 int dummy_entropy(void *data, unsigned char *output, size_t len)
79 {
80 size_t i;
81 (void) data;
82
83 //use mbedtls_entropy_func to find bugs in it
84 //test performance impact of entropy
85 //ret = mbedtls_entropy_func(data, output, len);
86 for (i = 0; i < len; i++) {
87 //replace result with pseudo random
88 output[i] = (unsigned char) rand();
89 }
90 return 0;
91 }
92
fuzz_recv_timeout(void * ctx,unsigned char * buf,size_t len,uint32_t timeout)93 int fuzz_recv_timeout(void *ctx, unsigned char *buf, size_t len,
94 uint32_t timeout)
95 {
96 (void) timeout;
97
98 return fuzz_recv(ctx, buf, len);
99 }
100