HMACSHA265 output difference between CryptoJS and Python

Question

I have a working CryptoJS signing that I need to translate to Python in order to run it in our testcases. The problem is that when I input the same parameter values and use the same algorithm it returns different resulting signing hashes in Python vs CryptoJS.

Code with CryptoJS:

<html>
<script src="https://cdnjs.cloudflare.com/ajax/libs/crypto-js/4.1.1/crypto-js.min.js"></script>
<script>
window.onload = function(){

    var privateKey = "F2FD99BA2BA7335BF0336CA0A5714F02042D073D3742A312";
    var targetSystem = "mydomain.de";
    
    var preDerivedKey = GetPreDerivedKey(privateKey, targetSystem, CurrentUtcDateTimeStamp());
}   

function CurrentUtcDateTimeStamp()
{
    // For debugging, set to 0 for now
    return "0";
};

function Encrypt(data, password)
{
    var hash = CryptoJS.HmacSHA256(data, password);
    
    console.log("Function Encrypt (using data '" + data + "' and password '" + password + "'), Hash is: " + hash);
    return hash;
};

function GetPreDerivedKey(privateKey, targetSystem, timestamp)
{
    console.log("Function GetPreDerivedKey received: privateKey '" +  privateKey + "', targetSystem '" + targetSystem + "', timestamp '" + timestamp + "'");
    var derivedKey = Encrypt(targetSystem, privateKey);
    derivedKey = Encrypt(timestamp, derivedKey);
    return derivedKey;
};
</script>
</html>

Code in Python:

import hashlib
import hmac

privateKey = "F2FD99BA2BA7335BF0336CA0A5714F02042D073D3742A312"
targetSystem = "mydomain.de"

def CurrentUtcDateTimeStamp():
    return "0"

def Encrypt(data, password):
    hash = hmac.new(password.encode('utf-8'),msg=data.encode('utf-8'),digestmod=hashlib.sha256).hexdigest()
    
    print("Function Encrypt (using data '" + data + "' and password '" + password + "'), Hash is:")
    
    hexstring = ""
    for bytes in hash:
        hexstring += str(bytes)
    print(hexstring)

    return hash

def GetPreDerivedKey(privateKey, targetSystem, timestamp):
    print("Function GetPreDerivedKey received: privateKey '" +  privateKey + "', targetSystem '" + targetSystem + "', timestamp '" + timestamp + "'")
    derivedKey = Encrypt(targetSystem, privateKey)
    derivedKey = Encrypt(timestamp, derivedKey)
    return derivedKey

# Signing
preDerivedKey = GetPreDerivedKey(privateKey, targetSystem, CurrentUtcDateTimeStamp());

Console output of both codes when executed.

PY

Function GetPreDerivedKey received: privateKey 'F2FD99BA2BA7335BF0336CA0A5714F02042D073D3742A312', targetSystem 'mydomain.de', timestamp '0'
Function Encrypt (using data 'mydomain.de' and password 'F2FD99BA2BA7335BF0336CA0A5714F02042D073D3742A312'), Hash is:
3c0f696075960ec05e0b0ace52594cd49855aff052489911608c6b9ea37a553e
Function Encrypt (using data '0' and password '3c0f696075960ec05e0b0ace52594cd49855aff052489911608c6b9ea37a553e'), Hash is:
48e5d0f3f6ac4563b765ff0caa9b09ec34cddbbc247185d50785a2b1e8b6eb59

JS

Function GetPreDerivedKey received: privateKey 'F2FD99BA2BA7335BF0336CA0A5714F02042D073D3742A312', targetSystem 'mydomain.de', timestamp '0' 
Function Encrypt (using data 'mydomain.de' and password 'F2FD99BA2BA7335BF0336CA0A5714F02042D073D3742A312'), Hash is:
3c0f696075960ec05e0b0ace52594cd49855aff052489911608c6b9ea37a553e
Function Encrypt (using data '0' and password '3c0f696075960ec05e0b0ace52594cd49855aff052489911608c6b9ea37a553e'), Hash is:
577ae299e95e289395c4614412b60dc527bdba2066ccd3e76af0e4cbb4cc4495

You can see the difference in the last line: 48e5d0f3f6ac4563b765ff0caa9b09ec34cddbbc247185d50785a2b1e8b6eb59 vs 577ae299e95e289395c4614412b60dc527bdba2066ccd3e76af0e4cbb4cc4495

Interestingly enough, the first iteration is still correct and shows the same result. Only the second iteration is different.

Any help would be appreciated, thanks!

Answer 1

Have you tried to return the hexstring instead of the hash in you python "Encrypt" function?

Answer 2

Got it running through the following code and thanks to Topaco's input:

targetSystem = "mydomain.de"
privateKey = "F2FD99BA2BA7335BF0336CA0A5714F02042D073D3742A312"

def CurrentUtcDateTimeStamp():
    return "0"

def Encrypt(data, password):
    
    print("Function Encrypt")

    # Convert the input parmeters depending on their data type. They are expected as byte or bytearray.
    if(isinstance(data, str)):
        print("Data: '" + data + "' (converted from string to byte)")
        data = data.encode("utf-8")
    if(isinstance(password, str)):
        print("Password '" + password + "' (converted from string to byte)")
        password = password.encode("utf-8")
    elif(isinstance(password, bytearray)):
        print("Password '" + str(password.hex()) + "'")

    hash = hmac.new(msg=data,key=password,digestmod=hashlib.sha256).hexdigest()

    # Convert hex-encoded data into a byte array
    hash_bytes = bytearray.fromhex(hash)

    # Print result
    hexstring = ""
    for bytes in hash:
        hexstring += str(bytes)
    print("Result:" + hexstring + "\n")
    return hash_bytes

def GetPreDerivedKey(privateKey, targetSystem, timestamp):
    print("Function GetPreDerivedKey received: privateKey '" +  privateKey + "', targetSystem '" + targetSystem + "', timestamp '" + timestamp + "'")
    print("")
    derivedKey = Encrypt(targetSystem, privateKey)
    derivedKey = Encrypt(timestamp, derivedKey)
    return derivedKey

# Signing
preDerivedKey = GetPreDerivedKey(privateKey, targetSystem, CurrentUtcDateTimeStamp());

HMACSHA265 output difference between CryptoJS and Python

Question

2 answers

solution1
0 2022-08-09 09:53:06

solution2
0 2022-08-09 12:29:16

HMACSHA265 output difference between CryptoJS and Python

Question

2 answers

solution1 0 2022-08-09 09:53:06

solution2 0 2022-08-09 12:29:16

solution1
0 2022-08-09 09:53:06

solution2
0 2022-08-09 12:29:16