Revision control

Copy as Markdown

Other Tools

/*
* (C) 2015,2016 Jack Lloyd
*
* Botan is released under the Simplified BSD License (see license.txt)
*/
#include "fuzzers.h"
#include <botan/eme_pkcs.h>
#include <botan/hex.h>
namespace {
std::vector<uint8_t> simple_pkcs1_unpad(const uint8_t in[], size_t len)
{
if(len < 10)
throw Botan::Decoding_Error("bad len");
if(in[0] != 0 || in[1] != 2)
throw Botan::Decoding_Error("bad header field");
for(size_t i = 2; i < len; ++i)
{
if(in[i] == 0)
{
if(i < 10) // at least 8 padding bytes required
throw Botan::Decoding_Error("insufficient padding bytes");
return std::vector<uint8_t>(in + i + 1, in + len);
}
}
throw Botan::Decoding_Error("delim not found");
}
}
void fuzz(const uint8_t in[], size_t len)
{
static Botan::EME_PKCS1v15 pkcs1;
Botan::secure_vector<uint8_t> lib_result;
std::vector<uint8_t> ref_result;
bool lib_rejected = false, ref_rejected = false;
try
{
uint8_t valid_mask = 0;
Botan::secure_vector<uint8_t> decoded = (static_cast<Botan::EME*>(&pkcs1))->unpad(valid_mask, in, len);
if(valid_mask == 0)
lib_rejected = true;
else if(valid_mask == 0xFF)
lib_rejected = false;
else
FUZZER_WRITE_AND_CRASH("Invalid valid_mask from unpad");
}
catch(Botan::Decoding_Error&) { lib_rejected = true; }
try
{
ref_result = simple_pkcs1_unpad(in, len);
}
catch(Botan::Decoding_Error& e) { ref_rejected = true; }
if(lib_rejected == true && ref_rejected == false)
{
FUZZER_WRITE_AND_CRASH("Library rejected input accepted by ref "
<< Botan::hex_encode(ref_result));
}
else if(ref_rejected == true && lib_rejected == false)
{
FUZZER_WRITE_AND_CRASH("Library accepted input rejected by ref "
<< Botan::hex_encode(lib_result));
}
// otherwise the two implementations agree
}