Implement FROST::Signature#decode

azuchi · Feb 15, 2024 · 07c234b · 07c234b
1 parent 1255a7b
commit 07c234b
Showing 1 changed file with 11 additions and 0 deletions.
diff --git a/lib/frost/signature.rb b/lib/frost/signature.rb
@@ -27,5 +27,16 @@ def encode
       ECDSA::Format::PointOctetString.encode(r, compression: true) +
         ECDSA::Format::IntegerOctetString.encode(s, 32)
     end
+
+    # Decode hex value to FROST::Signature.
+    # @param [String] hex_value Hex value of signature.
+    # @param [ECDSA::Group] group Group of elliptic curve.
+    # @return [FROST::Signature]
+    def self.decode(hex_value, group)
+      data = [hex_value].pack("H*")
+      r = ECDSA::Format::PointOctetString.decode(data[0...33], group)
+      s = ECDSA::Format::IntegerOctetString.decode(data[33..-1])
+      Signature.new(r,s )
+    end
   end
 end