feat(crypto): implement sign/3 for tz3

objkt-com · Mar 15, 2024 · 877ed12 · 877ed12
1 parent bbd4108
commit 877ed12
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Showing 2 changed files with 37 additions and 20 deletions.
diff --git a/lib/crypto.ex b/lib/crypto.ex
@@ -14,12 +14,17 @@ defmodule Tezex.Crypto do
   @prefix_edpk <<13, 15, 37, 217>>
   @prefix_sppk <<3, 254, 226, 86>>
   @prefix_p2pk <<3, 178, 139, 127>>
+  # public key hash
+  @prefix_tz1 <<6, 161, 159>>
+  @prefix_tz2 <<6, 161, 161>>
+  @prefix_tz3 <<6, 161, 164>>
   # private key
   @prefix_edsk <<43, 246, 78, 7>>
   @prefix_spsk <<17, 162, 224, 201>>
   @prefix_p2sk <<16, 81, 238, 189>>
   # sig
   @prefix_sig <<4, 130, 43>>
+  @prefix_p2sig <<54, 240, 44, 52>>
 
   @doc """
   Verify that `address` is the public key hash of `pubkey` and that `signature` is a valid signature for `message` signed with the private key corresponding to public key `pubkey`.
@@ -84,7 +89,7 @@ defmodule Tezex.Crypto do
 
   def verify_signature("p2" <> _ = signature, msg, pubkey) do
     # tz3…
-    <<54, 240, 44, 52, sig::binary-size(64)>> <> _ = Base58Check.decode58!(signature)
+    <<@prefix_p2sig, sig::binary-size(64)>> <> _ = Base58Check.decode58!(signature)
 
     <<r::unsigned-integer-size(256), s::unsigned-integer-size(256)>> = sig
     signature = %Signature{r: r, s: s}
@@ -151,18 +156,15 @@ defmodule Tezex.Crypto do
     case Base58Check.decode58(pubkey) do
       # tz1 addresses: "edpk" <> _
       {:ok, <<@prefix_edpk, public_key::binary-size(32)>> <> _} ->
-        pkh = <<6, 161, 159>>
-        derive_address(public_key, pkh)
+        derive_address(public_key, @prefix_tz1)
 
       # tz2 addresses: "sppk" <> _
       {:ok, <<@prefix_sppk, public_key::binary-size(33)>> <> _} ->
-        pkh = <<6, 161, 161>>
-        derive_address(public_key, pkh)
+        derive_address(public_key, @prefix_tz2)
 
       # tz3 addresses: "p2pk" <> _
       {:ok, <<@prefix_p2pk, public_key::binary-size(33)>> <> _} ->
-        pkh = <<6, 161, 164>>
-        derive_address(public_key, pkh)
+        derive_address(public_key, @prefix_tz3)
 
       _ ->
         {:error, :invalid_pubkey_format}
@@ -211,6 +213,7 @@ defmodule Tezex.Crypto do
       case key do
         "edsk" <> _ -> @prefix_edsk
         "spsk" <> _ -> @prefix_spsk
+        "p2sk" <> _ -> @prefix_p2sk
       end
 
     key = Base58Check.decode58!(key)
@@ -241,6 +244,20 @@ defmodule Tezex.Crypto do
 
         signature = :binary.decode_hex(r_bin <> s_bin)
 
+        Base58Check.encode(signature, @prefix_sig)
+
+      "p2sk" <> _ ->
+        pk = %PrivateKey{secret: decoded_key, curve: KnownCurves.prime256v1()}
+        s = ECDSA.sign(watermark <> msg, pk, hashfunc: fn msg -> Blake2.hash2b(msg, 32) end)
+
+        r_bin = Integer.to_string(s.r, 16)
+        s_bin = Integer.to_string(s.s, 16)
+
+        r_bin = Utils.pad(r_bin, 64, :leading)
+        s_bin = Utils.pad(s_bin, 64, :leading)
+
+        signature = :binary.decode_hex(r_bin <> s_bin)
+
         Base58Check.encode(signature, @prefix_sig)
     end
   end

diff --git a/test/crypto_test.exs b/test/crypto_test.exs
@@ -287,22 +287,22 @@ defmodule Tezex.Crypto.Test do
       assert signature == Crypto.sign(secret_key, bytes, watermark)
     end
 
-    # test "Tz3" do
-    #   encoded_private_key = "p2sk2obfVMEuPUnadAConLWk7Tf4Dt3n4svSgJwrgpamRqJXvaYcg1"
-    #   pubkey = "p2pk66tTYL5EvahKAXncbtbRPBkAnxo3CszzUho5wPCgWauBMyvybuB"
-    #   pubkeyhash = "tz3Lfm6CyfSTZ7EgMckptZZGiPxzs9GK59At"
-    #   secret_key = "p2sk2obfVMEuPUnadAConLWk7Tf4Dt3n4svSgJwrgpamRqJXvaYcg1"
+    test "Tz3" do
+      encoded_private_key = "p2sk2obfVMEuPUnadAConLWk7Tf4Dt3n4svSgJwrgpamRqJXvaYcg1"
+      pubkey = "p2pk66tTYL5EvahKAXncbtbRPBkAnxo3CszzUho5wPCgWauBMyvybuB"
+      pubkeyhash = "tz3Lfm6CyfSTZ7EgMckptZZGiPxzs9GK59At"
+      secret_key = "p2sk2obfVMEuPUnadAConLWk7Tf4Dt3n4svSgJwrgpamRqJXvaYcg1"
 
-    #   bytes = "1234"
-    #   watermark = <<3>>
+      bytes = "1234"
+      watermark = <<3>>
 
-    #   signature =
-    #     "sigRUobRZ4oG7CvdtQfNoDe3Gqn8zrLw6RXjXVa84rX3HMzWuCuncWgDqY8wRkssofLUsfbdR6MNGJzDWaNXEwTxDktfrKmj"
+      signature =
+        "sigRUobRZ4oG7CvdtQfNoDe3Gqn8zrLw6RXjXVa84rX3HMzWuCuncWgDqY8wRkssofLUsfbdR6MNGJzDWaNXEwTxDktfrKmj"
 
-    #   assert Crypto.derive_address(pubkey) == {:ok, pubkeyhash}
-    #   assert signature == Crypto.sign(encoded_private_key, bytes, watermark)
-    #   assert signature == Crypto.sign(secret_key, bytes, watermark)
-    # end
+      assert Crypto.derive_address(pubkey) == {:ok, pubkeyhash}
+      assert signature == Crypto.sign(encoded_private_key, bytes, watermark)
+      assert signature == Crypto.sign(secret_key, bytes, watermark)
+    end
 
     # test "Tz3 Encrypted" do
     #   encoded_private_key =