A java server use SHA256WithRSA to sign message, but python can not verify

Question

Here is the code, the second (message, signature and public key) works fine on Java, can verify the message. But when I am using python, it will failed. If am signed the message and the code will verify the message correctly. Would some one help me to check the problem? Thank you.

# -*- coding:utf-8 -*-
from Crypto.PublicKey import RSA
from Crypto.Hash import SHA256
from Crypto.Signature import PKCS1_v1_5
from base64 import b64decode, b64encode

public_key = 'MFwwDQYJKoZIhvcNAQEBBQADSwAwSAJBALyJy3rlD9EtWqVBzSIYxRRuFWRVn3juht2nupDCBSsWi7uKaRu3W0gn5y6aCacArtCkrf0EehwYRm0A4iHf8rkCAwEAAQ=='
private_key = 'MIIBVQIBADANBgkqhkiG9w0BAQEFAASCAT8wggE7AgEAAkEAvInLeuUP0S1apUHNIhjFFG4VZFWfeO6G3ae6kMIFKxaLu4ppG7dbSCfnLpoJpwCu0KSt/QR6HBhGbQDiId/yuQIDAQABAkEAqm/y15UtOE7Ey/HxLCqyNqbRhdN1h5AxsT0IhgYvP+PhWGc3hRElMwNCdiNaJBh04R1iK6wmKoi3DSjkdU6IAQIhAPRL9khAdPMxjy5tpswNWeaDjNJrlUKEnItQUkoHqve5AiEAxZIDz235HcUgLg9ApYK4spOpzLDGCCgfO3FxmrUEUwECIEaLjQIOQvdbT1p75Ze1H0nWoRq+YGrF+qKsPicMkc1ZAiARlNTR+K9afthGQQU3tVJKUemiVXjJ8QgWehnp8oHYAQIhANsC2fEVjWv94Oy2c8I9qhuX+yfNtvZ2m+Kmf2o4JFrR'
bank_response_data = """{"head":{"vernbr":"1.0","mchnbr":"BILL0003","mchtyp":"BILLTYP","trscod":"BILL001","msgidc":"201805011230500001","sigtim":"20190307115511","sigalg":"SHA256WithRSA","retcod":"F","retmsg":"GWB2B006 源IP地址不在商户IP白名单中；商户编号：BILL0003；IP地址：123.139.40.150"}}"""
bank_response_signature = """uZl0/5D694GnAd/G9OPRs9BSd9fb0fZGXSGThBtgLnKi+CDQAdasOX05mKazXZki0blXxApGYRAWa/kOrf+Wl0USfklx0G5w/eGERfMdRWpvtV3S2MBCH/H/0T81nKGgn8svkT/Trj7+Mc+e654Jn8IijGyV9m8Ak92hG2bLtbc="""
bank_public_key = """MIGfMA0GCSqGSIb3DQEBAQUAA4GNADCBiQKBgQDZs4l8Ez3F4MG0kF7RRSL+pn8MmxVE3nfdXzjx6d3rH8IfDbNvNRLS0X0b5iJnPyFO8sbbUo1Im4zX0M8XA0xnnviGyn5E6occiyUXJRgokphWb5BwaYdVhnLldctdimHoJTk3NFEQFav3guygR54i3tymrDc8lWtuG8EczVu8FwIDAQAB"""

def sign():
    key_bytes = bytes(private_key, encoding="utf-8")
    key_bytes = b64decode(key_bytes)
    key = RSA.importKey(key_bytes)
    hash_value = SHA256.new(bytes(bank_response_data, encoding="utf-8"))
    signer = PKCS1_v1_5.new(key)
    signature = signer.sign(hash_value)
    return b64encode(signature)


def verify(data, signature, the_pub_key):
    print(signature)
    key_bytes = bytes(the_pub_key, encoding="utf-8")
    key_bytes = b64decode(key_bytes)
    key = RSA.importKey(key_bytes)
    hash_value = SHA256.new(bytes(data, encoding="utf-8"))
    verifier = PKCS1_v1_5.new(key)
    if verifier.verify(hash_value, b64decode(signature)):
        print("The signature is authentic.")
    else:
        print("The signature is not authentic.")


verify(bank_response_data, sign(), public_key)
verify(bank_response_data, bank_response_signature.encode('utf-8'), 
bank_public_key)

score 0 · Answer 1 · answered Mar 07 '19 at 06:14

# -*- coding:utf-8 -*-
from Cryptodome.Signature import PKCS1_v1_5  # pip install pycryptodomex
from Cryptodome.Hash import SHA256
from Cryptodome.PublicKey import RSA
from base64 import decodebytes, encodebytes

public_key = "MFwwDQYJKoZIhvcNAQEBBQADSwAwSAJBALyJy3rlD9EtWqVBzSIYxRRuFWRVn3juht2nupDCBSsWi7uKaRu3W0gn5y6aCacArtCkrf0EehwYRm0A4iHf8rkCAwEAAQ=="
private_key = "MIIBVQIBADANBgkqhkiG9w0BAQEFAASCAT8wggE7AgEAAkEAvInLeuUP0S1apUHNIhjFFG4VZFWfeO6G3ae6kMIFKxaLu4ppG7dbSCfnLpoJpwCu0KSt/QR6HBhGbQDiId/yuQIDAQABAkEAqm/y15UtOE7Ey/HxLCqyNqbRhdN1h5AxsT0IhgYvP+PhWGc3hRElMwNCdiNaJBh04R1iK6wmKoi3DSjkdU6IAQIhAPRL9khAdPMxjy5tpswNWeaDjNJrlUKEnItQUkoHqve5AiEAxZIDz235HcUgLg9ApYK4spOpzLDGCCgfO3FxmrUEUwECIEaLjQIOQvdbT1p75Ze1H0nWoRq+YGrF+qKsPicMkc1ZAiARlNTR+K9afthGQQU3tVJKUemiVXjJ8QgWehnp8oHYAQIhANsC2fEVjWv94Oy2c8I9qhuX+yfNtvZ2m+Kmf2o4JFrR"
bank_response_data = """{"head":{"vernbr":"1.0","mchnbr":"BILL0003","mchtyp":"BILLTYP","trscod":"BILL001","msgidc":"201805011230500001","sigtim":"20190307115511","sigalg":"SHA256WithRSA","retcod":"F","retmsg":"GWB2B006 源IP地址不在商户IP白名单中；商户编号：BILL0003；IP地址：123.139.40.150"}}"""
bank_response_signature = """uZl0/5D694GnAd/G9OPRs9BSd9fb0fZGXSGThBtgLnKi+CDQAdasOX05mKazXZki0blXxApGYRAWa/kOrf+Wl0USfklx0G5w/eGERfMdRWpvtV3S2MBCH/H/0T81nKGgn8svkT/Trj7+Mc+e654Jn8IijGyV9m8Ak92hG2bLtbc="""
bank_public_key = """MIGfMA0GCSqGSIb3DQEBAQUAA4GNADCBiQKBgQDZs4l8Ez3F4MG0kF7RRSL+pn8MmxVE3nfdXzjx6d3rH8IfDbNvNRLS0X0b5iJnPyFO8sbbUo1Im4zX0M8XA0xnnviGyn5E6occiyUXJRgokphWb5BwaYdVhnLldctdimHoJTk3NFEQFav3guygR54i3tymrDc8lWtuG8EczVu8FwIDAQAB"""


def sign(private_key=private_key, raw_string=bank_response_data):
    private_key = RSA.importKey(decodebytes(private_key.encode()))
    signer = PKCS1_v1_5.new(private_key)
    signature = signer.sign(SHA256.new(raw_string.encode()))
    return encodebytes(signature).decode().replace("\n", "")


def verify(data, signature, public_key):
    print(signature)
    key = RSA.importKey(decodebytes(public_key.encode()))
    hash_value = SHA256.new(data.encode())
    verifier = PKCS1_v1_5.new(key)
    if verifier.verify(hash_value, decodebytes(signature.encode())):
        print("The signature is authentic.")
    else:
        print("The signature is not authentic.")


verify(bank_response_data, sign(), public_key)
verify(bank_response_data, bank_response_signature, bank_public_key)

It is not work. verify(bank_response_data, bank_response_signature, bank_public_key) will go "The signature is not authentic." — boykimi, Mar 07 '19 at 06:32
Why does `len(public_key) != len(bank_public_key)`? Maybe you should check the format of bank_public_key. — Waket Zheng, Mar 07 '19 at 07:27

score 0 · Answer 2 · answered Mar 07 '19 at 06:36

Below is the java code, it works fine with the same signature and public key.

import org.apache.commons.codec.digest.DigestUtils;

import java.security.KeyFactory;
import java.security.PrivateKey;
import java.security.PublicKey;
import java.security.Signature;
import java.security.spec.PKCS8EncodedKeySpec;
import java.security.spec.X509EncodedKeySpec;
import java.util.Base64;

public class MyTest {
    public static final String KEY_ALGORITHM = "RSA";
    public static final String SIGNATURE_ALGORITHM = "SHA256WithRSA";

public static void main(String[] args) {
    String data = "{\"head\":{\"vernbr\":\"1.0\",\"mchnbr\":\"BILL0003\",\"mchtyp\":\"BILLTYP\",\"trscod\":\"BILL001\",\"msgidc\":\"201805011230500001\",\"sigtim\":\"20190307115511\",\"sigalg\":\"SHA256WithRSA\",\"retcod\":\"F\",\"retmsg\":\"GWB2B006 源IP地址不在商户IP白名单中；商户编号：BILL0003；IP地址：123.139.40.150\"}}";

    String signature = "dnAFU2e5zFb8rJ1mXDNk5AG9UyujVIUArkBjb1Nonf7iMhZwHfHRO633eW5n7uELFnyJZk6Go2D6ovp4jEnIoA==";

    String cmbcRespSignature = "uZl0/5D694GnAd/G9OPRs9BSd9fb0fZGXSGThBtgLnKi+CDQAdasOX05mKazXZki0blXxApGYRAWa/kOrf+Wl0USfklx0G5w/eGERfMdRWpvtV3S2MBCH/H/0T81nKGgn8svkT/Trj7+Mc+e654Jn8IijGyV9m8Ak92hG2bLtbc=";
    String cmbcPublicKey = "MIGfMA0GCSqGSIb3DQEBAQUAA4GNADCBiQKBgQDZs4l8Ez3F4MG0kF7RRSL+pn8MmxVE3nfdXzjx6d3rH8IfDbNvNRLS0X0b5iJnPyFO8sbbUo1Im4zX0M8XA0xnnviGyn5E6occiyUXJRgokphWb5BwaYdVhnLldctdimHoJTk3NFEQFav3guygR54i3tymrDc8lWtuG8EczVu8FwIDAQAB";

    try {
        boolean verify = verify(DigestUtils.sha256(data), cmbcPublicKey, cmbcRespSignature);
        if (verify) {

        }
    } catch (Exception e) {

    }
}

public static boolean verify(byte[] data, String publicKey, String sign) throws Exception {
    final Base64.Decoder decoder = Base64.getDecoder();
    final byte[] keyBytes = publicKey.getBytes("UTF-8");

    X509EncodedKeySpec keySpec = new X509EncodedKeySpec(decoder.decode(keyBytes));

    KeyFactory keyFactory = KeyFactory.getInstance(KEY_ALGORITHM);

    PublicKey pubKey = keyFactory.generatePublic(keySpec);

    Signature signature = Signature.getInstance(SIGNATURE_ALGORITHM);
    signature.initVerify(pubKey);
    signature.update(data);

    return signature.verify(decoder.decode(sign));
}

}

You have posted multiple answers. Stackoverflow is not a forum. Please combine your "answers" into one and delete the other. — Robert, Mar 10 '19 at 15:42

score 0 · Answer 3 · answered Mar 07 '19 at 10:34

0

Finally, I get the answer. In java

DigestUtils.sha256(data) did hash, SHA256WithRSA algorithm will do hash

So what I should do is hash 2 times in my python code

answered Mar 07 '19 at 10:34

boykimi

1
1

You have posted multiple answers. Stackoverflow is not a forum. Please combine your "answers" into one and delete the other. – Robert Mar 10 '19 at 15:42

A java server use SHA256WithRSA to sign message, but python can not verify

3 Answers3