diff --git a/libi2pd/ECIESX25519AEADRatchetSession.cpp b/libi2pd/ECIESX25519AEADRatchetSession.cpp index 9c76320b..8faf1cd9 100644 --- a/libi2pd/ECIESX25519AEADRatchetSession.cpp +++ b/libi2pd/ECIESX25519AEADRatchetSession.cpp @@ -1104,7 +1104,8 @@ namespace garlic return true; } - static size_t CreateGarlicPayload (std::shared_ptr msg, uint8_t * payload, bool datetime) + static size_t CreateGarlicPayload (std::shared_ptr msg, uint8_t * payload, + bool datetime, size_t optimalSize) { size_t len = 0; if (datetime) @@ -1129,11 +1130,20 @@ namespace garlic len += cloveSize + 3; payload += cloveSize; // padding - uint8_t paddingSize = rand () & 0x0F; // 0 - 15 - payload[0] = eECIESx25519BlkPadding; - htobe16buf (payload + 1, paddingSize); - if (paddingSize) memset (payload + 3, 0, paddingSize); - len += paddingSize + 3; + int delta = (int)optimalSize - (int)len; + if (delta < 0 || delta > 3) // don't create padding if we are close to optimal size + { + uint8_t paddingSize = rand () & 0x0F; // 0 - 15 + if (delta > 3) + { + delta -= 3; + if (paddingSize > delta) paddingSize %= delta; + } + payload[0] = eECIESx25519BlkPadding; + htobe16buf (payload + 1, paddingSize); + if (paddingSize) memset (payload + 3, 0, paddingSize); + len += paddingSize + 3; + } return len; } @@ -1145,7 +1155,7 @@ namespace garlic size_t offset = 0; memcpy (buf + offset, &tag, 8); offset += 8; auto payload = buf + offset; - size_t len = CreateGarlicPayload (msg, payload, false); + size_t len = CreateGarlicPayload (msg, payload, false, 956); // 1003 - 8 tag - 16 Poly1305 hash - 16 I2NP header - 4 garlic length - 3 local tunnel delivery uint8_t nonce[12]; memset (nonce, 0, 12); // n = 0 if (!i2p::crypto::AEADChaCha20Poly1305 (payload, len, buf, 8, key, nonce, payload, len + 16, true)) // encrypt @@ -1181,7 +1191,7 @@ namespace garlic } noiseState.MixKey (sharedSecret); auto payload = buf + offset; - size_t len = CreateGarlicPayload (msg, payload, true); + size_t len = CreateGarlicPayload (msg, payload, true, 900); // 1003 - 32 eph key - 16 Poly1305 hash - 16 I2NP header - 4 garlic length - 35 router tunnel delivery uint8_t nonce[12]; memset (nonce, 0, 12); // encrypt payload