Add sha256 signature support(with fallback to sha). (#7)

* Add sha256 signature support(with fallback to sha).

* Update CHANGELOG(Add SHA256 signature support)

---------

Co-authored-by: Gleb Ivanov <ivanov@panzerdog.com>

Author: realglebivanov

CHANGELOG.md

@@ -2,6 +2,7 @@
 
 ## master
 
+- Support SHA256 signatures(with a fallback to SHA) in `ReceiptDecoder.Verifier`
 - Require Elixir 1.13.
 
 ## v0.5.0

lib/receipt_decoder/verifier/verifier.ex

@@ -118,7 +118,9 @@ defmodule ReceiptDecoder.Verifier do
     public_key = extract_public_key(itunes_cert)
 
     with {:ok, payload} <- Extractor.extract_payload(receipt),
-         true <- :public_key.verify(payload, :sha, signature, public_key) do
+         true <-
+           :public_key.verify(payload, :sha256, signature, public_key) or
+             :public_key.verify(payload, :sha, signature, public_key) do
       :ok
     else
       false ->