fix: make rsa_pss int_to_bit_size more efficient

Author: jfrain99

src/rsa_pss.erl

@@ -12,6 +12,7 @@
 -module(rsa_pss).
 
 -include_lib("public_key/include/public_key.hrl").
+-include("include/hb.hrl").
 
 %% API
 -export([sign/3]).
@@ -88,7 +89,7 @@ verify({digest, Digest}, DigestType, Signature, PublicKey=#'RSAPublicKey'{modulu
     PrivateByteSize = (PublicBitSize + 7) div 8,
     PublicByteSize = int_to_byte_size(N),
     SignatureSize = byte_size(Signature),
-    case PublicByteSize =:= SignatureSize of
+    Ret = case PublicByteSize =:= SignatureSize of
         true ->
             SignatureNumber = binary:decode_unsigned(Signature, big),
             case SignatureNumber >= 0 andalso SignatureNumber < N of
@@ -124,7 +125,8 @@ verify({digest, Digest}, DigestType, Signature, PublicKey=#'RSAPublicKey'{modulu
             end;
         false ->
             false
-    end.
+    end,
+    Ret.
 
 verify_legacy(Message, DigestType, Signature, PublicKey) when is_binary(Message) ->
     verify_legacy({digest, crypto:hash(DigestType, Message)}, DigestType, Signature, PublicKey);
@@ -185,16 +187,9 @@ ep(B, #'RSAPublicKey'{modulus=N, publicExponent=E}) ->
     crypto:mod_pow(B, E, N).
 
 %% @private
-int_to_bit_size(I) ->
-    int_to_bit_size(I, 0).
+int_to_bit_size(I) -> 
+    bit_size(binary:encode_unsigned(I)).
 
-%% @private
-int_to_bit_size(0, B) ->
-    B;
-int_to_bit_size(I, B) ->
-    int_to_bit_size(I bsr 1, B + 1).
-
-%% @private
 int_to_byte_size(I) ->
     int_to_byte_size(I, 0).