Get Ruby's OpenSSL::HMAC.hexdigest() to output the same as PHP's hash_hmac()

Question

I'm trying to use the API of a web service provider. They don't have an example in Ruby, but they do have one for PHP, and I'm trying to interpret between the two. The API examples always use "true" on PHP's hash_hmac() call, which produces a binary output. The difference seems to be that Ruby's OpenSSL::HMAC.hexdigest() function always returns text. (If I change the PHP call to "false" they return the same value.) Does anyone know of a way to "encode" the text returned from OpenSSL::HMAC.hexdigest() to get the same thing as returned from a hash_hmac('sha256', $text, $key, true)?

Answer 1

使用OpenSSL::HMAC.digest获取二进制输出。

Answer 2

You'll need to convert each pair of hex digits into a byte with the same value. I don't know any Ruby, but this is similar to how it would be handled in PHP.

First, take your string of hex digits and split them into an array. Each element in the array should be two characters long. Convert each element from a string of two hex bytes to an integer. It looks like you can do this by calling the hex method on each string.

Next, call pack on the converted array using the parameter c* , to convert each integer into a one-byte character. You should get the correct string of bytes as the result.