rsa_key_en.md

RSA Key for Alipay

中文

Table of Contents

• Generate Application Key
  • Generate RSA2 Keypair in Ruby
  • Saving Key
  • Extract Key Content
• Signing Parameters
• Formatting the Public Key from Alipay

Generate Application Key

Generate RSA2 Keypair in Ruby

This example creates a 2048 bits RSA2 key. It is recommended by Alipay that you use a RSA2 key.

require 'openssl'

@app_key = OpenSSL::PKey::RSA.new(2048)

Saving Key

You can save your private and public key as any of two formats. As long as it can be loaded into the program.

Saving Private Key to String

app_private_key = @app_key.to_s

Saving Private Key to File

open 'private_key.pem', 'w' do |io| io.write @app_key.to_pem end

Saving Public Key to String

app_public_key = @app_key.public_key.to_s

Saving Public Key to File

open 'public_key.pem', 'w' do |io| io.write @app_key.public_key.to_pem end

Extract Key Content

You will need to submit the application public key that you just created to Alipay. However, you will need to strip the header, footer, and new line characters from the key and just submit the key content to Alipay.

key_content = app_public_key.gsub(/(-----BEGIN PUBLIC KEY-----)|(-----END PUBLIC KEY-----)|(\n)/, "")
puts key_content
# => 'MII0ey6QDZLB69i0e5Q0....'

Signing Parameters

After you submit your application's public key to Alipay. There is an optional step to validate the public key that you just uploaded by signing a parameter provided by Alipay.

# validate params "a=123"
Base64.strict_encode64(@app_key.sign('sha256', "a=123"))
# => 'FokDu5uwgmNG2O/cb0QYD....'

Formatting the Public Key from Alipay

The public key from Alipay does not contain any formatting. Ruby's OpenSSL library cannot import/read the public key without proper formatting. To add formatting back, run the following script.

pub_key = "MIIBI...HpwIDAQAB"
pub_key.scan(/.{64}|.+$/).join("\n").insert(0, "-----BEGIN PUBLIC KEY-----\n").insert(-1, "\n-----END PUBLIC KEY-----\n")
# => "-----BEGIN PUBLIC KEY-----\nMIIBI...\n-----END PUBLIC KEY-----\n"