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Initial commit of garlic

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orignal 2013-11-23 16:35:15 -05:00
parent 474aa9068a
commit e0e5e8ad36
3 changed files with 122 additions and 5 deletions
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18
ElGamal.h
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@ -12,23 +12,31 @@ namespace i2p
{
namespace crypto
{
inline void ElGamalEncrypt (const uint8_t * key, const uint8_t * data, int len, uint8_t * encrypted)
inline void ElGamalEncrypt (const uint8_t * key, const uint8_t * data, int len,
uint8_t * encrypted, bool zeroPadding = false) // 514 with padding and 512 without
{
CryptoPP::AutoSeededRandomPool rnd;
CryptoPP::Integer y(key, 256), k(rnd, CryptoPP::Integer::One(), elgp-1);
a_exp_b_mod_c (elgg, k, elgp).Encode (encrypted, 256);
if (zeroPadding)
{
encrypted[0] = 0;
encrypted[257] = 0;
}
a_exp_b_mod_c (elgg, k, elgp).Encode (zeroPadding ? encrypted + 1 : encrypted, 256);
uint8_t m[255];
m[0] = 0xFF;
memcpy (m+33, data, len);
CryptoPP::SHA256().CalculateDigest(m+1, m+33, 222);
a_times_b_mod_c (a_exp_b_mod_c (y, k, elgp),
CryptoPP::Integer (m, 255), elgp).Encode (encrypted + 256, 256);
CryptoPP::Integer (m, 255), elgp).Encode (zeroPadding ? encrypted + 258 : encrypted + 256, 256);
}
inline bool ElGamalDecrypt (const uint8_t * key, const uint8_t * encrypted, uint8_t * data)
inline bool ElGamalDecrypt (const uint8_t * key, const uint8_t * encrypted,
uint8_t * data, bool zeroPadding = false)
{
CryptoPP::Integer x(key, 256), a(encrypted, 256), b(encrypted + 256, 256);
CryptoPP::Integer x(key, 256), a(zeroPadding? encrypted +1 : encrypted, 256),
b(zeroPadding? encrypted + 258 :encrypted + 256, 256);
uint8_t m[255], hash[32];
a_times_b_mod_c (b, a_exp_b_mod_c (a, elgp - x - 1, elgp), elgp).Encode (m, 255);
CryptoPP::SHA256().CalculateDigest(hash, m+33, 222);