From 1e75de9bb80d19f48d2cb6b2f0b4a609f6d233ed Mon Sep 17 00:00:00 2001
From: orignal <i2porignal@yandex.ru>
Date: Wed, 8 Nov 2017 21:06:58 -0500
Subject: [PATCH] 514 bytes ECIES block
---
libi2pd/Crypto.cpp | 18 ++++++++++--------
libi2pd/Crypto.h | 2 +-
2 files changed, 11 insertions(+), 9 deletions(-)
diff --git a/libi2pd/Crypto.cpp b/libi2pd/Crypto.cpp
index 13c86188..ddd42f0d 100644
--- a/libi2pd/Crypto.cpp
+++ b/libi2pd/Crypto.cpp
@@ -385,10 +385,11 @@ namespace crypto
auto p = EC_POINT_new (curve);
EC_POINT_mul (curve, p, k, nullptr, nullptr, ctx);
BIGNUM * x = BN_CTX_get (ctx), * y = BN_CTX_get (ctx);
- EC_POINT_get_affine_coordinates_GFp (curve, p, x, y, nullptr);
- bn2buf (x, encrypted, len);
- bn2buf (y, encrypted + len, len);
- RAND_bytes (encrypted + 2*len, 256 - 2*len);
+ EC_POINT_get_affine_coordinates_GFp (curve, p, x, y, nullptr);
+ encrypted[0] = 0;
+ bn2buf (x, encrypted + 1, len);
+ bn2buf (y, encrypted + 1 + len, len);
+ RAND_bytes (encrypted + 1 + 2*len, 256 - 2*len);
// ecryption key and iv
EC_POINT_mul (curve, p, nullptr, key, k, ctx);
EC_POINT_get_affine_coordinates_GFp (curve, p, x, y, nullptr);
@@ -402,10 +403,11 @@ namespace crypto
memcpy (m+33, data, 222);
SHA256 (m+33, 222, m+1);
// encrypt
+ encrypted[257] = 0;
CBCEncryption encryption;
encryption.SetKey (shared);
encryption.SetIV (iv);
- encryption.Encrypt (m, 256, encrypted + 256);
+ encryption.Encrypt (m, 256, encrypted + 258);
EC_POINT_free (p);
BN_CTX_end (ctx);
}
@@ -419,8 +421,8 @@ namespace crypto
int len = BN_num_bytes (q);
// point for shared secret
BIGNUM * x = BN_CTX_get (ctx), * y = BN_CTX_get (ctx);
- BN_bin2bn (encrypted, len, x);
- BN_bin2bn (encrypted + len, len, y);
+ BN_bin2bn (encrypted + 1, len, x);
+ BN_bin2bn (encrypted + 1 + len, len, y);
auto p = EC_POINT_new (curve);
if (EC_POINT_set_affine_coordinates_GFp (curve, p, x, y, nullptr))
{
@@ -437,7 +439,7 @@ namespace crypto
CBCDecryption decryption;
decryption.SetKey (shared);
decryption.SetIV (iv);
- decryption.Decrypt (encrypted + 256, 256, m);
+ decryption.Decrypt (encrypted + 258, 256, m);
// verify and copy
uint8_t hash[32];
SHA256 (m + 33, 222, hash);
diff --git a/libi2pd/Crypto.h b/libi2pd/Crypto.h
index 68378b4e..2b1bf6a0 100644
--- a/libi2pd/Crypto.h
+++ b/libi2pd/Crypto.h
@@ -53,7 +53,7 @@ namespace crypto
void GenerateElGamalKeyPair (uint8_t * priv, uint8_t * pub);
// ECIES
- void ECIESEncrypt (const EC_GROUP * curve, const EC_POINT * key, const uint8_t * data, uint8_t * encrypted, BN_CTX * ctx); // 222 bytes data, 512 bytes encrypted
+ void ECIESEncrypt (const EC_GROUP * curve, const EC_POINT * key, const uint8_t * data, uint8_t * encrypted, BN_CTX * ctx); // 222 bytes data, 514 bytes encrypted
bool ECIESDecrypt (const EC_GROUP * curve, const BIGNUM * key, const uint8_t * encrypted, uint8_t * data, BN_CTX * ctx);
void GenerateECIESKeyPair (const EC_GROUP * curve, BIGNUM *& priv, EC_POINT *& pub);