59 lines
2 KiB
Python
59 lines
2 KiB
Python
import hashlib
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import base64
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import lib.pybitcointools as btctools
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ecc_cache = {}
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def eciesEncrypt(data, pubkey, ephemcurve=None, ciphername='aes-256-cbc'):
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import pyelliptic
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pubkey_openssl = toOpensslPublickey(base64.b64decode(pubkey))
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curve, pubkey_x, pubkey_y, i = pyelliptic.ECC._decode_pubkey(pubkey_openssl)
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if ephemcurve is None:
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ephemcurve = curve
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ephem = pyelliptic.ECC(curve=ephemcurve)
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key = hashlib.sha512(ephem.raw_get_ecdh_key(pubkey_x, pubkey_y)).digest()
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key_e, key_m = key[:32], key[32:]
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pubkey = ephem.get_pubkey()
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iv = pyelliptic.OpenSSL.rand(pyelliptic.OpenSSL.get_cipher(ciphername).get_blocksize())
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ctx = pyelliptic.Cipher(key_e, iv, 1, ciphername)
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ciphertext = iv + pubkey + ctx.ciphering(data)
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mac = pyelliptic.hmac_sha256(key_m, ciphertext)
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return key_e, ciphertext + mac
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def eciesDecrypt(encrypted_data, privatekey):
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ecc_key = getEcc(privatekey)
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return ecc_key.decrypt(base64.b64decode(encrypted_data))
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def split(encrypted):
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iv = encrypted[0:16]
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ciphertext = encrypted[16 + 70:-32]
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return iv, ciphertext
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def getEcc(privatekey=None):
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import pyelliptic
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global ecc_cache
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if privatekey not in ecc_cache:
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if privatekey:
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publickey_bin = btctools.encode_pubkey(btctools.privtopub(privatekey), "bin")
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publickey_openssl = toOpensslPublickey(publickey_bin)
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privatekey_openssl = toOpensslPrivatekey(privatekey)
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ecc_cache[privatekey] = pyelliptic.ECC(curve='secp256k1', privkey=privatekey_openssl, pubkey=publickey_openssl)
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else:
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ecc_cache[None] = pyelliptic.ECC()
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return ecc_cache[privatekey]
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def toOpensslPrivatekey(privatekey):
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privatekey_bin = btctools.encode_privkey(privatekey, "bin")
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return b'\x02\xca\x00\x20' + privatekey_bin
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def toOpensslPublickey(publickey):
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publickey_bin = btctools.encode_pubkey(publickey, "bin")
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publickey_bin = publickey_bin[1:]
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publickey_openssl = b'\x02\xca\x00 ' + publickey_bin[:32] + b'\x00 ' + publickey_bin[32:]
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return publickey_openssl
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