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/*
* (C) 2015,2016 Jack Lloyd
*
* Botan is released under the Simplified BSD License (see license.txt)
*/
#include "fuzzers.h"
#include <botan/numthry.h>
#include <botan/reducer.h>
void fuzz(const uint8_t in[], size_t len)
{
// Ressol is mostly used for ECC point decompression so best to test smaller sizes
static const size_t p_bits = 256;
static const Botan::BigInt p = random_prime(fuzzer_rng(), p_bits);
static const Botan::Modular_Reducer mod_p(p);
if(len > p_bits / 8)
return;
try
{
const Botan::BigInt a = Botan::BigInt::decode(in, len);
Botan::BigInt a_sqrt = Botan::ressol(a, p);
if(a_sqrt > 0)
{
const Botan::BigInt a_redc = mod_p.reduce(a);
const Botan::BigInt z = mod_p.square(a_sqrt);
if(z != a_redc)
{
FUZZER_WRITE_AND_CRASH("A = " << a << "\n"
<< "P = " << p << "\n"
<< "R = " << a_sqrt << "\n"
<< "Z = " << z << "\n");
}
}
}
catch(Botan::Exception& e) {}
return;
}
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