Bitstamp - new authentication in C# - signature - c#

The new authentication of bitstamp says the following:
Signature is a HMAC-SHA256 encoded message containing: nonce, client ID and API key. The HMAC-SHA256 code must be generated using a secret key that was generated with your API key. This code must be converted to it's hexadecimal representation (64 uppercase characters).Example (Python):
message = nonce + client_id + api_key
signature = hmac.new(API_SECRET, msg=message, digestmod=hashlib.sha256).hexdigest().upper()
Source: link
I've got the following code to add the new signature (and other parameters):
public void AddApiAuthentication(RestRequest restRequest)
{
var nonce = DateTime.Now.Ticks;
var signature = GetSignature(nonce, apiKey, apiSecret, clientId);
restRequest.AddParameter("key", apiKey);
restRequest.AddParameter("signature", signature);
restRequest.AddParameter("nonce", nonce);
}
private string GetSignature(long nonce, string key, string secret, string clientId)
{
string msg = string.Format("{0}{1}{2}", nonce,
clientId,
key);
return ByteArrayToString(SignHMACSHA256(secret, StrinToByteArray(msg))).ToUpper();
}
public static byte[] SignHMACSHA256(String key, byte[] data)
{
HMACSHA256 hashMaker = new HMACSHA256(Encoding.ASCII.GetBytes(key));
return hashMaker.ComputeHash(data);
}
public static byte[] StrinToByteArray(string str)
{
byte[] bytes = new byte[str.Length * sizeof(char)];
System.Buffer.BlockCopy(str.ToCharArray(), 0, bytes, 0, bytes.Length);
return bytes;
}
public static string ByteArrayToString(byte[] hash)
{
return BitConverter.ToString(hash).Replace("-", "").ToLower();
}
And then I get this error:
{"error": "Invalid signature"}
Anyone got an idea what the problem could be? I checked my parameters a 100 times and those aren't wrong. Maybe somebody got a working piece of code (in C#) for the new authentication?
UPDATE
Abhinav was right, the StringToByteArray method was wrong (not only the typo :P) the working code is:
public static byte[] StrinToByteArray(string str)
{
return System.Text.Encoding.ASCII.GetBytes(str);
}

You are using str.ToCharArray() in StrinToByteArray which is incorrect (correct ONLY when used on the same system). You need to use ASCII encoding or something.

Related

How do I verify the Weavy webhook signature?

I have registered a webhook and provided a secret as documented on https://www.weavy.com/docs/backend/webhooks.
When the payload is delivered to my url I want to verify the signature, but I can't seem to get the calculation correct. What am I doing wrong?
Here is the code I'm using:
public static bool Verify(string signature, string body, string secret)
{
using (var hmac = new HMACSHA256(Encoding.UTF8.GetBytes(secret)))
{
var hashBytes = hmac.ComputeHash(Encoding.UTF8.GetBytes(body));
var hash = Encoding.UTF8.GetString(hashBytes);
return signature.Equals(hash);
}
}
The documentation says the signature is a HMAC hex digest so instead of converting hashBytes to an UTF8 string you should convert it to a hexadecimal string.
public static bool Verify(string signature, string body, string secret)
{
using (var hmac = new HMACSHA256(Encoding.UTF8.GetBytes(Secret)))
{
var hashBytes = hmac.ComputeHash(Encoding.UTF8.GetBytes(body));
var hash = Convert.ToHexString(hashBytes).ToLowerInvariant();
return signature.Equals(hash);
}
}

Google KMS giving error when decrypting data

When i try to decrypt my data using the Google KMS i am getting this error. Below is my code for the decryption. The error is hitting on the line where there is string plaintext. Thanks in advance
Code
public static string Encrypt(string plaintext)
{
KeyManagementServiceClient client = KeyManagementServiceClient.Create();
//projects/progforthecloudt2020/locations/global/keyRings/pfckeyring001/cryptoKeys/pfckeys
CryptoKeyName kn = CryptoKeyName.FromUnparsed(new
Google.Api.Gax.UnparsedResourceName("GOOGLE RESOURCE ID REMOVED"));
string cipher = client.Encrypt(kn, ByteString.CopyFromUtf8(plaintext)).Ciphertext.ToBase64();
return cipher;
}
public static string Decrypt(string cipher)
{
KeyManagementServiceClient client = KeyManagementServiceClient.Create();
CryptoKeyName kn = CryptoKeyName.FromUnparsed(new Google.Api.Gax.UnparsedResourceName("GOOGLE RESOURCE ID REMOVED"));
string plaintext = client.Decrypt(kn, ByteString.CopyFromUtf8(cipher)).Plaintext.ToBase64();
return plaintext;
}
Error
Grpc.Core.RpcException: 'Status(StatusCode=InvalidArgument, Detail="Decryption failed: the ciphertext is invalid.")'
You’re base64 encoding the result of your encryption call, but then you aren’t base64 decoding it in your decrypt call. You shouldn’t need to base64 encode the data.
public static void Encrypt(string projectId, string locationId, string keyRingId, string cryptoKeyId, string plaintextFile, string ciphertextFile)
{
KeyManagementServiceClient client = KeyManagementServiceClient.Create();
CryptoKeyName cryptoKeyName =
new CryptoKeyName(projectId, locationId, keyRingId, cryptoKeyId);
byte[] plaintext = File.ReadAllBytes(plaintextFile);
EncryptResponse result = client.Encrypt(cryptoKeyName, ByteString.CopyFrom(plaintext));
// Output encrypted data to a file.
File.WriteAllBytes(ciphertextFile, result.Ciphertext.ToByteArray());
Console.Write($"Encrypted file created: {ciphertextFile}");
}
public static void Decrypt(string projectId, string locationId, string keyRingId, string cryptoKeyId, string ciphertextFile, string plaintextFile)
{
KeyManagementServiceClient client = KeyManagementServiceClient.Create();
CryptoKeyName cryptoKeyName =
new CryptoKeyName(projectId, locationId, keyRingId, cryptoKeyId);
byte[] ciphertext = File.ReadAllBytes(ciphertextFile);
DecryptResponse result = client.Decrypt(cryptoKeyName, ByteString.CopyFrom(ciphertext));
// Output decrypted data to a file.
File.WriteAllBytes(plaintextFile, result.Plaintext.ToByteArray());
Console.Write($"Decrypted file created: {plaintextFile}");
}

Password hashing in UWP

I have the following code in .net framework.
public string GetHashedPassword(string password, string salt)
{
byte[] saltArray = Convert.FromBase64String(salt);
byte[] passArray = Convert.FromBase64String(password);
byte[] salted = new byte[saltArray.Length + passArray.Length];
byte[] hashed = null;
saltArray.CopyTo(salted, 0);
passArray.CopyTo(salted, saltArray.Length);
using (var hash = new SHA256Managed())
{
hashed = hash.ComputeHash(salted);
}
return Convert.ToBase64String(hashed);
}
I'm trying to create an equivalent in .net core for a UWP application. Here's what I have so far.
public string GetHashedPassword(string password, string salt)
{
IBuffer input = CryptographicBuffer.ConvertStringToBinary(password + salt, BinaryStringEncoding.Utf8);
var hashAlgorithm = HashAlgorithmProvider.OpenAlgorithm(HashAlgorithmNames.Sha256);
var hash = hashAlgorithm.HashData(input);
//return CryptographicBuffer.ConvertBinaryToString(BinaryStringEncoding.Utf8, hash);
}
The last line, converting the buffer back to a string doesn't work. I get this exception:
No mapping for the Unicode character exists in the target multi-byte code page.
How can I convert the buffer back into a string?
I am assuming, that you want to get the hashed password in a base64-format, because you did that in your .net example.
To get this, change:
CryptographicBuffer.ConvertBinaryToString(BinaryStringEncoding.Utf8, hash);
to:
CryptographicBuffer.EncodeToBase64String(hash);
So the complete method looks like this:
public string GetHashedPassword(string password, string salt)
{
IBuffer input = CryptographicBuffer.ConvertStringToBinary(password + salt, BinaryStringEncoding.Utf8);
var hashAlgorithm = HashAlgorithmProvider.OpenAlgorithm(HashAlgorithmNames.Sha256);
var hash = hashAlgorithm.HashData(input);
return CryptographicBuffer.EncodeToBase64String(hash);
}

hashing "SHA256" with two parameters

I must convert a JAVA function that Hashing a string.
this is a function:
private static String hmacSha256(String value, String key) throws NoSuchAlgorithmException, InvalidKeyException {
byte[] keyBytes = key.getBytes();
SecretKeySpec signingKey = new SecretKeySpec(keyBytes, "HmacSHA256");
Mac mac = Mac.getInstance("HmacSHA256");
mac.init(signingKey);
byte[] rawHmac = mac.doFinal(value.getBytes());
return String.format("%0" + (rawHmac.length << 1) + "x", new BigInteger(1, rawHmac));
}
My doubt is: this function take 2 parameters:
String value: It is the string to crypt
String Key: It is another key
I already used the Sha256, but I always use it with only one parameter (one string to encrypt)
please, how can I wrote this function in c# or is there anyone who can explain to me the logical?
thank you
You can use HMACSHA256 class to make it work:
private static string ComputeHash(string key, string value)
{
var byteKey = Encoding.UTF8.GetBytes(key);
string hashString;
using (var hmac = new HMACSHA256(byteKey))
{
var hash = hmac.ComputeHash(Encoding.UTF8.GetBytes(value));
hashString = Convert.ToBase64String(hash);
}
return hashString;
}
This is not plain SHA256, this is HMACSHA256 and there is allready a class in .Net.
HMACSHA256

How to convert and send string in Http Authorization Header?

I am developing a REST API. Client puts it's user name and password in authorization header of HttpClient after encrypting it with public key of Server. Username and password will always consist of alphabets and number which means it can be represented in ASCII.
I am using this code for encryption.
string encrypted = Encrypt (someText, crypto);
public static string Encrypt (string plainText, RSACryptoServiceProvider crypto)
{
var plainData = GetBytes (plainText);
var encryptedData = crypto.Encrypt (plainData, true);
return GetString (encryptedData);
}
public static byte[] GetBytes (string str)
{
var bytes = new byte[str.Length * sizeof (char)];
Buffer.BlockCopy (str.ToCharArray (), 0, bytes, 0, bytes.Length);
return bytes;
}
public static string GetString (byte[] bytes)
{
var chars = new char[bytes.Length / sizeof (char)];
Buffer.BlockCopy (bytes, 0, chars, 0, bytes.Length);
return new string (chars);
}
Problem is that I get this string after encryption
꠨屰欧㼡‫⭮鍴⬎㔾䐛え멩戻덒郝㬭ே䉚ꑰ䵇᷹᷶虣ⱒ̿ঊࠎ飳枹鬭쉦폩��ᤫ槺愐丄裘ډ졽肟䷋ٱ᮷튼쁡鮤붮飦ꃨ◡뉋⭠夏旻浨፛᠏რ
I can't send these Unicode characters in the authorization header. Is there any way to get the encrypted text in ASCII so that it can easily be sent through HttpClient?
You can base64 encode it. Base64 encoding produces a string that is suitable for sending over a transport that supports ASCII strings.
public static string Encrypt (string plainText, RSACryptoServiceProvider crypto)
{
var plainData = GetBytes (plainText);
var encryptedData = crypto.Encrypt (plainData, true);
return Convert.ToBase64String (encryptedData);
}
Btw, I would replace your custom GetBytes method for converting the string to an array of bytes with Encoding.GetBytes; which is the built in and preferred method of doing that. For instance:
var plainData = System.Text.Encoding.UTF8.GetBytes(plainText);

Categories

Resources