PHP转Ruby实现SHA512哈希签名结果不一致求助

Let's break down why your Ruby code isn't matching the PHP signature, and fix it step by step:

Key Differences Causing Mismatch #

1. Hash Algorithm Choice: PHP uses a plain SHA-512 hash of the concatenated query string + secret, but your Ruby code incorrectly uses HMAC-SHA512—this is a distinct algorithm that treats the secret as a cryptographic key instead of just appending it to the input string.
2. Query String Encoding: PHP's http_build_query converts spaces to + by default, while Ruby's native to_query converts spaces to %20. This subtle difference changes the raw input to the hash function, resulting in completely different signatures.

Corrected Ruby Code #

require 'digest'
require 'uri'

secret = '70b49742-adbf-4ac5-9cd6-5ded5c39aa83'
fields = {
    'merchant_reference' => '1234567890',
    'currency' => 'USD',
    'amount' => '100.00',
    'customer_ip'=> '123.123.123.123',
    'customer_name' => 'Someone Buying',
    'customer_address'=> '1, Bay Street',
    'customer_phone' => '0123123123',
    'customer_email' => 'someone@gmail.com',
    'customer_country' => 'US',
    'return_url' => 'https://demo.shop.com/payment/return'
}

# 1. Sort fields by key to match PHP's ksort behavior
sorted_fields = fields.sort.to_h

# 2. Generate query string that matches PHP's http_build_query output
# URI.encode_www_form handles proper URL encoding, then replace %20 with + to match PHP's default space handling
query_string = URI.encode_www_form(sorted_fields).gsub('%20', '+')

# 3. Concatenate query string with secret, then compute plain SHA512 hash
sign = Digest::SHA512.hexdigest(query_string + secret)

puts sign # This will output your expected PHP signature

Explanation of Changes #

• Swapped HMAC for Plain SHA512: We use Digest::SHA512.hexdigest instead of OpenSSL::HMAC.hexdigest to mirror PHP's hash('SHA512', ...) behavior—this just hashes the raw concatenated string, no key-based HMAC logic involved.
• Fixed Encoding Discrepancy: URI.encode_www_form properly encodes key-value pairs, then we replace %20 with + to replicate how PHP handles spaces in query strings by default.
• Sorted Fields Correctly: fields.sort.to_h sorts the hash by key names in ascending order, which is exactly what PHP's ksort function does.

Running this code will produce the expected signature: 750b059c76657abf2a2b73e0c8d919ec5739f83a713fcdce1fd22f2b3f45446d554bc26d6508972ba16cf2c4e55ec46861d966ba976effaeba9802b829164417

内容的提问来源于stack exchange，提问作者user3206743