amino: Copy signature encoding from launchpad

packages/amino/src/signature.spec.ts

@@ -0,0 +1,65 @@
+/* eslint-disable @typescript-eslint/naming-convention */
+import { fromBase64 } from "@cosmjs/encoding";
+
+import { decodeSignature, encodeSecp256k1Signature, StdSignature } from "./signature";
+
+describe("signature", () => {
+  describe("encodeSecp256k1Signature", () => {
+    it("encodes a full signature", () => {
+      const pubkey = fromBase64("AtQaCqFnshaZQp6rIkvAPyzThvCvXSDO+9AzbxVErqJP");
+      const signature = fromBase64(
+        "1nUcIH0CLT0/nQ0mBTDrT6kMG20NY/PsH7P2gc4bpYNGLEYjBmdWevXUJouSE/9A/60QG9cYeqyTe5kFDeIPxQ==",
+      );
+      expect(encodeSecp256k1Signature(pubkey, signature)).toEqual({
+        pub_key: {
+          type: "tendermint/PubKeySecp256k1",
+          value: "AtQaCqFnshaZQp6rIkvAPyzThvCvXSDO+9AzbxVErqJP",
+        },
+        signature: "1nUcIH0CLT0/nQ0mBTDrT6kMG20NY/PsH7P2gc4bpYNGLEYjBmdWevXUJouSE/9A/60QG9cYeqyTe5kFDeIPxQ==",
+      });
+    });
+
+    it("throws when getting uncompressed public keys", () => {
+      const pubkey = fromBase64(
+        "BE8EGB7ro1ORuFhjOnZcSgwYlpe0DSFjVNUIkNNQxwKQE7WHpoHoNswYeoFkuYpYSKK4mzFzMV/dB0DVAy4lnNU=",
+      );
+      const signature = fromBase64(
+        "1nUcIH0CLT0/nQ0mBTDrT6kMG20NY/PsH7P2gc4bpYNGLEYjBmdWevXUJouSE/9A/60QG9cYeqyTe5kFDeIPxQ==",
+      );
+      expect(() => encodeSecp256k1Signature(pubkey, signature)).toThrowError(
+        /public key must be compressed secp256k1/i,
+      );
+    });
+
+    it("throws if signature contains recovery byte", () => {
+      const pubkey = fromBase64("AtQaCqFnshaZQp6rIkvAPyzThvCvXSDO+9AzbxVErqJP");
+      const signature = Uint8Array.from([
+        ...fromBase64(
+          "1nUcIH0CLT0/nQ0mBTDrT6kMG20NY/PsH7P2gc4bpYNGLEYjBmdWevXUJouSE/9A/60QG9cYeqyTe5kFDeIPxQ==",
+        ),
+        99,
+      ]);
+      expect(() => encodeSecp256k1Signature(pubkey, signature)).toThrowError(
+        /signature must be 64 bytes long/i,
+      );
+    });
+  });
+
+  describe("decodeSignature", () => {
+    it("works for secp256k1", () => {
+      const signature: StdSignature = {
+        pub_key: {
+          type: "tendermint/PubKeySecp256k1",
+          value: "AtQaCqFnshaZQp6rIkvAPyzThvCvXSDO+9AzbxVErqJP",
+        },
+        signature: "1nUcIH0CLT0/nQ0mBTDrT6kMG20NY/PsH7P2gc4bpYNGLEYjBmdWevXUJouSE/9A/60QG9cYeqyTe5kFDeIPxQ==",
+      };
+      expect(decodeSignature(signature)).toEqual({
+        pubkey: fromBase64("AtQaCqFnshaZQp6rIkvAPyzThvCvXSDO+9AzbxVErqJP"),
+        signature: fromBase64(
+          "1nUcIH0CLT0/nQ0mBTDrT6kMG20NY/PsH7P2gc4bpYNGLEYjBmdWevXUJouSE/9A/60QG9cYeqyTe5kFDeIPxQ==",
+        ),
+      });
+    });
+  });
+});

packages/amino/src/signature.ts

@@ -0,0 +1,44 @@
+/* eslint-disable @typescript-eslint/naming-convention */
+import { fromBase64, toBase64 } from "@cosmjs/encoding";
+
+import { encodeSecp256k1Pubkey } from "./encoding";
+import { Pubkey, pubkeyType } from "./pubkeys";
+
+export interface StdSignature {
+  readonly pub_key: Pubkey;
+  readonly signature: string;
+}
+
+/**
+ * Takes a binary pubkey and signature to create a signature object
+ *
+ * @param pubkey a compressed secp256k1 public key
+ * @param signature a 64 byte fixed length representation of secp256k1 signature components r and s
+ */
+export function encodeSecp256k1Signature(pubkey: Uint8Array, signature: Uint8Array): StdSignature {
+  if (signature.length !== 64) {
+    throw new Error(
+      "Signature must be 64 bytes long. Cosmos SDK uses a 2x32 byte fixed length encoding for the secp256k1 signature integers r and s.",
+    );
+  }
+
+  return {
+    pub_key: encodeSecp256k1Pubkey(pubkey),
+    signature: toBase64(signature),
+  };
+}
+
+export function decodeSignature(
+  signature: StdSignature,
+): { readonly pubkey: Uint8Array; readonly signature: Uint8Array } {
+  switch (signature.pub_key.type) {
+    // Note: please don't add cases here without writing additional unit tests
+    case pubkeyType.secp256k1:
+      return {
+        pubkey: fromBase64(signature.pub_key.value),
+        signature: fromBase64(signature.signature),
+      };
+    default:
+      throw new Error("Unsupported pubkey type");
+  }
+}