ruby-signature-sample

require 'openssl'
require 'base64'
require 'digest'
 
# Generate Digest
def generateDigest(jsonBody)
    return Base64.encode64(Digest::SHA256.digest(jsonBody)).strip()
end
 
def generateSignature(clientId, requestId, requestTimestamp, requestTarget, digest, secret)
    # Prepare Signature Component
    puts "----- Component Signature -----"
    componentSignature = ("Client-Id:" + clientId")
    componentSignature.concat("\n")
    componentSignature.concat("Request-Id:" + requestId)
    componentSignature.concat("\n")
    componentSignature.concat("Request-Timestamp:" + requestTimestamp)
    componentSignature.concat("\n")
    componentSignature.concat("Request-Target:" + requestTarget)
    # If body not send when access API with HTTP method GET/DELETE
    unless digest.to_s.strip.empty?
        componentSignature.concat("\n")
        componentSignature.concat("Digest:" + digest)
    end
    puts componentSignature
    puts "\n"  

    # Calculate HMAC-SHA256 base64 from all the components above
    hash = OpenSSL::HMAC.digest("sha256", secret, componentSignature)
    signature = Base64.encode64(hash).strip()

    # Prepend encoded result with algorithm info HMACSHA256=
    return "HMACSHA256="+signature 
end
 
# Sample of Usage

# Generate Digest from JSON Body, For HTTP Method GET/DELETE don't need generate Digest
puts "----- Digest -----"
jsonBody = '{\"order\":{\"invoice_number\":\"INV-20210124-0001\",\"amount\":150000},\"virtual_account_info\":{\"expired_time\":60,\"reusable_status\":false,\"info1\":\"Merchant Demo Store\"},\"customer\":{\"name\":\"Taufik Ismail\",\"email\":\"taufik@example.com\"}}'
digest = generateDigest(jsonBody)
puts digest
puts "\n"
 
# Generate Header Signature
headerSignature = generateSignature(
        "yourClientId",
        "yourRequestId",
        "2020-10-21T03:38:28Z",
        "/request-target/goes-here", # For merchant request to Jokul, use Jokul path here. For HTTP Notification, use merchant path here
        digest, # Set empty string for this argumentes if HTTP Method is GET/DELETE
        "secret-key-from-jokul-back-office")
puts "----- Header Signature -----"
puts headerSignature