#
#                 Ethereum P2P
#              (c) Copyright 2018
#       Status Research & Development GmbH
#
#    See the file "LICENSE", included in this
#    distribution, for details about the copyright.
#

import unittest
import eth/keys, nimcrypto/[utils, sha2, hmac, rijndael]
import eth/p2p/ecies

proc compare[A, B](x: openarray[A], y: openarray[B], s: int = 0): bool =
  result = true
  doAssert(s >= 0)
  var size = if s == 0: min(len(x), len(y)) else: min(s, min(len(x), len(y)))
  for i in 0..(size - 1):
    if x[i] != cast[A](y[i]):
      result = false
      break

template offsetOf(a, b): int =
  cast[int](cast[uint](unsafeAddr b) - cast[uint](unsafeAddr a))

let rng = newRng()

suite "ECIES test suite":
  test "ECIES structures alignment":
    var header: EciesHeader
    check:
      offsetOf(header, header.version) == 0
      offsetOf(header, header.pubkey) == 1
      offsetOf(header, header.iv) == 1 + 64
      offsetOf(header, header.data) == 1 + 64 + aes128.sizeBlock
      sizeof(header) == 1 + 64 + aes128.sizeBlock + 1

  test "KDF test vectors":
    # KDF test
    # Copied from https://github.com/ethereum/pydevp2p/blob/develop/devp2p/tests/test_ecies.py#L53
    let m0 = "961c065873443014e0371f1ed656c586c6730bf927415757f389d92acf8268df"
    let c0 = "4050c52e6d9c08755e5a818ac66fabe478b825b1836fd5efc4d44e40d04dabcc"
    var m = fromHex(stripSpaces(m0))
    var c = fromHex(stripSpaces(c0))
    var k = kdf(m)
    check compare(k, c) == true

  test "HMAC-SHA256 test vectors":
    # HMAC-SHA256 test
    # https://github.com/ethereum/py-evm/blob/master/tests/p2p/test_ecies.py#L64-L76
    const keys = [
      "07a4b6dfa06369a570f2dcba2f11a18f",
      "af6623e52208c596e17c72cea6f1cb09"
    ]
    const datas = ["4dcb92ed4fc67fe86832", "3461282bcedace970df2"]
    const expects = [
      "c90b62b1a673b47df8e395e671a68bfa68070d6e2ef039598bb829398b89b9a9",
      "b3ce623bce08d5793677ba9441b22bb34d3e8a7de964206d26589df3e8eb5183"
    ]
    for i in 0..1:
      var k = fromHex(stripSpaces(keys[i]))
      var m = fromHex(stripSpaces(datas[i]))
      var digest = sha256.hmac(k, m).data
      var expect = fromHex(stripSpaces(expects[i]))
      check compare(digest, expect) == true

  test "ECIES \"Hello World!\" encryption/decryption test":
    # ECIES encryption
    var m = "Hello World!"
    var plain = cast[seq[byte]](m)
    var encr = newSeq[byte](eciesEncryptedLength(len(m)))
    var decr = newSeq[byte](len(m))
    var shmac = [0x13'u8, 0x13'u8]
    var s = PrivateKey.random(rng[])
    var p = s.toPublicKey()

    eciesEncrypt(rng[], plain, encr, p).expect("encryption should succeed")
    eciesDecrypt(encr, decr, s).expect("decryption should succeed")

    check:
      # Without additional mac data
      equalMem(addr m[0], addr decr[0], len(m))
    # With additional mac data
    eciesEncrypt(rng[], plain, encr, p, shmac).expect("encryption should succeed")
    eciesDecrypt(encr, decr, s, shmac).expect("decryption should succeed")

    check:
      equalMem(addr m[0], addr decr[0], len(m))

  test "ECIES/py-evm/cpp-ethereum test_ecies.py#L43/rlpx.cpp#L187":
    # ECIES
    # https://github.com/ethereum/py-evm/blob/master/tests/p2p/test_ecies.py#L43
    # https://github.com/ethereum/cpp-ethereum/blob/develop/test/unittests/libp2p/rlpx.cpp#L187
    const secretKeys = [
      "c45f950382d542169ea207959ee0220ec1491755abe405cd7498d6b16adb6df8",
      "5e173f6ac3c669587538e7727cf19b782a4f2fda07c1eaa662c593e5e85e3051"
    ]
    const cipherText = [
      """04a0274c5951e32132e7f088c9bdfdc76c9d91f0dc6078e848f8e3361193dbdc
         43b94351ea3d89e4ff33ddcefbc80070498824857f499656c4f79bbd97b6c51a
         514251d69fd1785ef8764bd1d262a883f780964cce6a14ff206daf1206aa073a
         2d35ce2697ebf3514225bef186631b2fd2316a4b7bcdefec8d75a1025ba2c540
         4a34e7795e1dd4bc01c6113ece07b0df13b69d3ba654a36e35e69ff9d482d88d
         2f0228e7d96fe11dccbb465a1831c7d4ad3a026924b182fc2bdfe016a6944312
         021da5cc459713b13b86a686cf34d6fe6615020e4acf26bf0d5b7579ba813e77
         23eb95b3cef9942f01a58bd61baee7c9bdd438956b426a4ffe238e61746a8c93
         d5e10680617c82e48d706ac4953f5e1c4c4f7d013c87d34a06626f498f34576d
         c017fdd3d581e83cfd26cf125b6d2bda1f1d56""",
      """049934a7b2d7f9af8fd9db941d9da281ac9381b5740e1f64f7092f3588d4f87f
         5ce55191a6653e5e80c1c5dd538169aa123e70dc6ffc5af1827e546c0e958e42
         dad355bcc1fcb9cdf2cf47ff524d2ad98cbf275e661bf4cf00960e74b5956b79
         9771334f426df007350b46049adb21a6e78ab1408d5e6ccde6fb5e69f0f4c92b
         b9c725c02f99fa72b9cdc8dd53cff089e0e73317f61cc5abf6152513cb7d833f
         09d2851603919bf0fbe44d79a09245c6e8338eb502083dc84b846f2fee1cc310
         d2cc8b1b9334728f97220bb799376233e113"""
    ]
    const expectText = [
      """884c36f7ae6b406637c1f61b2f57e1d2cab813d24c6559aaf843c3f48962f32f
         46662c066d39669b7b2e3ba14781477417600e7728399278b1b5d801a519aa57
         0034fdb5419558137e0d44cd13d319afe5629eeccb47fd9dfe55cc6089426e46
         cc762dd8a0636e07a54b31169eba0c7a20a1ac1ef68596f1f283b5c676bae406
         4abfcce24799d09f67e392632d3ffdc12e3d6430dcb0ea19c318343ffa7aae74
         d4cd26fecb93657d1cd9e9eaf4f8be720b56dd1d39f190c4e1c6b7ec66f077bb
         1100""",
      """802b052f8b066640bba94a4fc39d63815c377fced6fcb84d27f791c9921ddf3e
         9bf0108e298f490812847109cbd778fae393e80323fd643209841a3b7f110397
         f37ec61d84cea03dcc5e8385db93248584e8af4b4d1c832d8c7453c0089687a7
         00"""
    ]
    var data: array[1024, byte]
    for i in 0..1:
      var s = PrivateKey.fromHex(secretKeys[i])[]
      var cipher = fromHex(stripSpaces(cipherText[i]))
      var expect = fromHex(stripSpaces(expectText[i]))

      eciesDecrypt(cipher, data, s).expect("decryption should succeed")

      check:
        compare(data, expect) == true

  test "ECIES/cpp-ethereum rlpx.cpp#L432-L459":
    # ECIES
    # https://github.com/ethereum/cpp-ethereum/blob/develop/test/unittests/libp2p/rlpx.cpp#L432-L459
    const secretKeys = [
      "57baf2c62005ddec64c357d96183ebc90bf9100583280e848aa31d683cad73cb",
      "472413e97f1fd58d84e28a559479e6b6902d2e8a0cee672ef38a3a35d263886b",
      "472413e97f1fd58d84e28a559479e6b6902d2e8a0cee672ef38a3a35d263886b",
      "472413e97f1fd58d84e28a559479e6b6902d2e8a0cee672ef38a3a35d263886b"
    ]
    const cipherData = [
      """04ff2c874d0a47917c84eea0b2a4141ca95233720b5c70f81a8415bae1dc7b74
         6b61df7558811c1d6054333907333ef9bb0cc2fbf8b34abb9730d14e0140f455
         3f4b15d705120af46cf653a1dc5b95b312cf8444714f95a4f7a0425b67fc064d
         18f4d0a528761565ca02d97faffdac23de10""",
      """046f647e1bd8a5cd1446d31513bac233e18bdc28ec0e59d46de453137a725995
         33f1e97c98154343420d5f16e171e5107999a7c7f1a6e26f57bcb0d2280655d0
         8fb148d36f1d4b28642d3bb4a136f0e33e3dd2e3cffe4b45a03fb7c5b5ea5e65
         617250fdc89e1a315563c20504b9d3a72555""",
      """0443c24d6ccef3ad095140760bb143078b3880557a06392f17c5e368502d7953
         2bc18903d59ced4bbe858e870610ab0d5f8b7963dd5c9c4cf81128d10efd7c7a
         a80091563c273e996578403694673581829e25a865191bdc9954db14285b56eb
         0043b6288172e0d003c10f42fe413222e273d1d4340c38a2d8344d7aadcbc846
         ee""",
      """04c4e40c86bb5324e017e598c6d48c19362ae527af8ab21b077284a4656c8735
         e62d73fb3d740acefbec30ca4c024739a1fcdff69ecaf03301eebf156eb5f17c
         ca6f9d7a7e214a1f3f6e34d1ee0ec00ce0ef7d2b242fbfec0f276e17941f9f1b
         fbe26de10a15a6fac3cda039904ddd1d7e06e7b96b4878f61860e47f0b84c8ce
         b64f6a900ff23844f4359ae49b44154980a626d3c73226c19e"""
    ]
    const expectData = [
      "a", "a", "aaaaaaaaaaaaaaaa", "aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa"
    ]
    var data: array[1024, byte]
    for i in 0..3:
      var s = PrivateKey.fromHex(secretKeys[i])[]
      var cipher = fromHex(stripSpaces(cipherData[i]))
      check:
        eciesDecrypt(cipher, data, s).isOk()
        compare(data, expectData[i]) == true