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/*
* (C) 2015,2016,2018 Jack Lloyd
*
* Botan is released under the Simplified BSD License (see license.txt)
*/
#include "fuzzers.h"
#include <botan/divide.h>
void fuzz(const uint8_t in[], size_t len)
{
if(len % 2 == 1 || len > 2*4096/8)
return;
// Save on allocations by making these static
static Botan::BigInt x, y, q, r, ct_q, ct_r, z;
x = Botan::BigInt::decode(in, len / 2);
y = Botan::BigInt::decode(in + len / 2, len / 2);
if(y == 0)
return;
Botan::divide(x, y, q, r);
FUZZER_ASSERT_TRUE(r < y);
z = q*y + r;
FUZZER_ASSERT_EQUAL(z, x);
Botan::ct_divide(x, y, ct_q, ct_r);
FUZZER_ASSERT_EQUAL(q, ct_q);
FUZZER_ASSERT_EQUAL(r, ct_r);
// Now divide by just low byte of y
y = y.byte_at(0);
if(y == 0)
y = 251;
Botan::divide(x, y, q, r);
z = q*y + r;
FUZZER_ASSERT_EQUAL(z, x);
uint8_t r8;
Botan::ct_divide_u8(x, y.byte_at(0), ct_q, r8);
FUZZER_ASSERT_EQUAL(ct_q, q);
FUZZER_ASSERT_EQUAL(r8, r.byte_at(0));
}
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