#include "common.h"

#include <limits.h>

#include <stdio.h>

#include <string.h>

#include <stdlib.h>

#include "mbedtls/ctr_drbg.h"

#if defined(MBEDTLS_PLATFORM_TIME_ALT)

mbedtls_time_t dummy_constant_time(mbedtls_time_t *time)

{

    (void) time;

    return 0x5af2a056;

}

#endif

void dummy_init(void)

{

#if defined(MBEDTLS_PLATFORM_TIME_ALT)

    mbedtls_platform_set_time(dummy_constant_time);

#else

    fprintf(stderr, "Warning: fuzzing without constant time\n");

#endif

}

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

    if (len > INT_MAX) {

        return -1;

    }

    return (int) len;

}

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 > INT_MAX) {

        return -1;

    }

    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 (int) len;

}

int dummy_random(void *p_rng, unsigned char *output, size_t output_len)

{

    int ret;

    size_t i;

#if defined(MBEDTLS_CTR_DRBG_C)

    //mbedtls_ctr_drbg_random requires a valid mbedtls_ctr_drbg_context in p_rng

    if (p_rng != NULL) {

        //use mbedtls_ctr_drbg_random to find bugs in it

        ret = mbedtls_ctr_drbg_random(p_rng, output, output_len);

    } else {

        //fall through to pseudo-random

        ret = 0;

    }

#else

    (void) p_rng;

    ret = 0;

#endif

    for (i = 0; i < output_len; i++) {

        //replace result with pseudo random

        output[i] = (unsigned char) rand();

    }

    return ret;

}

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 fuzz_recv_timeout(void *ctx, unsigned char *buf, size_t len,

                      uint32_t timeout)

{

    (void) timeout;

    return fuzz_recv(ctx, buf, len);

}