feat: decode transaction signature and public key

src/crypto/address.ts

@@ -95,23 +95,23 @@ export class Address {
   }
 
   /** Encode the address to the writer. */
-  encode(writer: Writer): void {
+  encode(w: Writer): void {
     if (this.isTreasuryAddress()) {
-      writer.writeUint8(AddressType.TREASURY);
+      w.writeUint8(AddressType.TREASURY);
     } else {
-      writer.writeFixedBytes(this.rawBytes());
+      w.writeFixedBytes(this.rawBytes());
     }
   }
 
   /** Decode an Address from the reader. */
-  static decode(reader: Reader): Address {
-    const addrType = reader.readUint8();
+  static decode(r: Reader): Address {
+    const addrType = r.readUint8();
 
     if (addrType === AddressType.TREASURY) {
       return new Address(AddressType.TREASURY, new Uint8Array(20));
     }
 
-    const data = reader.readFixedBytes(20);
+    const data = r.readFixedBytes(20);
 
     return new Address(addrType as AddressType, data);
   }

src/crypto/interfaces.ts

@@ -0,0 +1,55 @@
+import type { Writer } from '../encoding';
+
+/**
+ * Interface for a public key that can verify signatures.
+ *
+ * Concrete implementations: ed25519.PublicKey, bls.PublicKey
+ */
+export interface IPublicKey {
+  /** Raw key material. */
+  rawBytes(): Uint8Array;
+
+  /** Bech32m-encoded string representation (e.g. "public1..."). */
+  string(): string;
+
+  /** Encode the key to the writer. */
+  encode(w: Writer): void;
+
+  /** Verify a signature against a message. */
+  verify(msg: Uint8Array, sig: ISignature): boolean;
+}
+
+/**
+ * Interface for a cryptographic signature.
+ *
+ * Concrete implementations: ed25519.Signature, bls.Signature
+ */
+export interface ISignature {
+  /** Raw signature bytes. */
+  rawBytes(): Uint8Array;
+
+  /** Hex-encoded string representation. */
+  string(): string;
+
+  /** Encode the signature to the writer. */
+  encode(w: Writer): void;
+}
+
+/**
+ * Interface for a private key that can sign messages.
+ *
+ * Concrete implementations: ed25519.PrivateKey, bls.PrivateKey
+ */
+export interface IPrivateKey {
+  /** Raw scalar bytes. */
+  rawBytes(): Uint8Array;
+
+  /** Bech32m-encoded string representation (e.g. "secret1..."). */
+  string(): string;
+
+  /** Derive the corresponding public key. */
+  publicKey(): IPublicKey;
+
+  /** Sign a message and return the signature. */
+  sign(msg: Uint8Array): ISignature;
+}

src/crypto/utils.ts

@@ -38,3 +38,18 @@ export function hexToBytes(hex: string): Uint8Array {
 
   return bytes;
 }
+
+/**
+ * Decode a bech32m-encoded public key string into raw bytes.
+ *
+ * Validates the HRP against the given value (default "public" for mainnet).
+ */
+export function decodeBech32PublicKey(text: string, expectedHrp: string = 'public'): Uint8Array {
+  const { hrp, data } = decodeWithType(text);
+
+  if (hrp !== expectedHrp) {
+    throw new Error(`Invalid public key hrp: ${hrp}, expected: ${expectedHrp}`);
+  }
+
+  return data;
+}

src/index.ts

@@ -4,7 +4,7 @@
  */
 
 export * from './wallet';
-export * from './transaction/transaction';
+export * from './transaction';
 export * from './transaction/payload';
 export { Address } from './crypto/address';
 export { Amount } from './types/amount';

src/transaction/index.ts

@@ -0,0 +1,2 @@
+export * from './transaction';
+export * from './payload';

src/transaction/payload/_payload.ts

@@ -11,7 +11,7 @@ export enum PayloadType {
 }
 
 export interface Payload {
-  encode(writer: Writer): void;
+  encode(w: Writer): void;
   getType(): PayloadType;
   signer(): Address;
 }

src/transaction/payload/bond.ts

@@ -12,18 +12,18 @@ export class BondPayload {
     public readonly stake: Amount
   ) {}
 
-  encode(writer: Writer): void {
-    this.sender.encode(writer);
-    this.receiver.encode(writer);
+  encode(w: Writer): void {
+    this.sender.encode(w);
+    this.receiver.encode(w);
 
     if (this.publicKey === null) {
-      writer.writeVarInt(0);
+      w.writeVarInt(0);
     } else {
-      writer.writeVarInt(96);
-      writer.writeFixedBytes(this.publicKey);
+      w.writeVarInt(96);
+      w.writeFixedBytes(this.publicKey);
     }
 
-    this.stake.encode(writer);
+    this.stake.encode(w);
   }
 
   getType(): PayloadType {
@@ -34,19 +34,19 @@ export class BondPayload {
     return this.sender;
   }
 
-  static decode(reader: Reader): BondPayload {
-    const sender = Address.decode(reader);
-    const receiver = Address.decode(reader);
-    const pubKeySize = reader.readVarInt();
+  static decode(r: Reader): BondPayload {
+    const sender = Address.decode(r);
+    const receiver = Address.decode(r);
+    const pubKeySize = r.readVarInt();
     let publicKey: Uint8Array | null = null;
 
     if (pubKeySize === 96n) {
-      publicKey = reader.readFixedBytes(96);
+      publicKey = r.readFixedBytes(96);
     } else if (pubKeySize !== 0n) {
       throw new Error(`invalid public key size: ${pubKeySize}`);
     }
 
-    const stake = Amount.decode(reader);
+    const stake = Amount.decode(r);
 
     return new BondPayload(sender, receiver, publicKey, stake);
   }

src/transaction/payload/sortition.ts

@@ -9,9 +9,9 @@ export class SortitionPayload {
     public readonly proof: Uint8Array
   ) {}
 
-  encode(writer: Writer): void {
-    this.address.encode(writer);
-    writer.writeFixedBytes(this.proof);
+  encode(w: Writer): void {
+    this.address.encode(w);
+    w.writeFixedBytes(this.proof);
   }
 
   getType(): PayloadType {
@@ -22,9 +22,9 @@ export class SortitionPayload {
     return this.address;
   }
 
-  static decode(reader: Reader): SortitionPayload {
-    const address = Address.decode(reader);
-    const proof = reader.readFixedBytes(48);
+  static decode(r: Reader): SortitionPayload {
+    const address = Address.decode(r);
+    const proof = r.readFixedBytes(48);
 
     return new SortitionPayload(address, proof);
   }

src/transaction/payload/transfer.ts

@@ -1,6 +1,6 @@
 import { Address } from '../../crypto/address';
 import { Amount } from '../../types/amount';
-import type { Writer, Reader } from '../../encoding';
+import type { Writer as w, Reader } from '../../encoding';
 
 import { PayloadType } from './_payload';
 
@@ -11,10 +11,10 @@ export class TransferPayload {
     public readonly amount: Amount
   ) {}
 
-  encode(writer: Writer): void {
-    this.sender.encode(writer);
-    this.receiver.encode(writer);
-    this.amount.encode(writer);
+  encode(w: w): void {
+    this.sender.encode(w);
+    this.receiver.encode(w);
+    this.amount.encode(w);
   }
 
   getType(): PayloadType {
@@ -25,10 +25,10 @@ export class TransferPayload {
     return this.sender;
   }
 
-  static decode(reader: Reader): TransferPayload {
-    const sender = Address.decode(reader);
-    const receiver = Address.decode(reader);
-    const amount = Amount.decode(reader);
+  static decode(r: Reader): TransferPayload {
+    const sender = Address.decode(r);
+    const receiver = Address.decode(r);
+    const amount = Amount.decode(r);
 
     return new TransferPayload(sender, receiver, amount);
   }

src/transaction/payload/unbond.ts

@@ -1,13 +1,13 @@
 import { Address } from '../../crypto/address';
-import type { Writer, Reader } from '../../encoding';
+import type { Writer as w, Reader } from '../../encoding';
 
 import { PayloadType } from './_payload';
 
 export class UnbondPayload {
   constructor(public readonly validator: Address) {}
 
-  encode(writer: Writer): void {
-    this.validator.encode(writer);
+  encode(w: w): void {
+    this.validator.encode(w);
   }
 
   getType(): PayloadType {
@@ -18,8 +18,8 @@ export class UnbondPayload {
     return this.validator;
   }
 
-  static decode(reader: Reader): UnbondPayload {
-    const validator = Address.decode(reader);
+  static decode(r: Reader): UnbondPayload {
+    const validator = Address.decode(r);
 
     return new UnbondPayload(validator);
   }

src/transaction/payload/withdraw.ts

@@ -11,10 +11,10 @@ export class WithdrawPayload {
     public readonly amount: Amount
   ) {}
 
-  encode(writer: Writer): void {
-    this.fromAddr.encode(writer);
-    this.toAddr.encode(writer);
-    this.amount.encode(writer);
+  encode(w: Writer): void {
+    this.fromAddr.encode(w);
+    this.toAddr.encode(w);
+    this.amount.encode(w);
   }
 
   getType(): PayloadType {
@@ -25,10 +25,10 @@ export class WithdrawPayload {
     return this.fromAddr;
   }
 
-  static decode(reader: Reader): WithdrawPayload {
-    const fromAddr = Address.decode(reader);
-    const toAddr = Address.decode(reader);
-    const amount = Amount.decode(reader);
+  static decode(r: Reader): WithdrawPayload {
+    const fromAddr = Address.decode(r);
+    const toAddr = Address.decode(r);
+    const amount = Amount.decode(r);
 
     return new WithdrawPayload(fromAddr, toAddr, amount);
   }

src/transaction/transaction.test.ts

@@ -1,10 +1,11 @@
-import { Transaction } from './transaction';
+import { Transaction, FLAG_NOT_SIGNED } from './transaction';
 import { Address } from '../crypto/address';
 import { Amount } from '../types/amount';
 import { Height } from '../types/height';
-import { Reader } from '../encoding';
+import { Reader, Writer } from '../encoding';
 import type { TransferPayload, BondPayload } from './payload';
 import { PayloadType } from './payload';
+import { PrivateKey as Ed25519PrivateKey } from '../crypto/ed25519/private_key';
 
 describe('Transaction', () => {
   describe('decode transfer transaction', () => {
@@ -44,11 +45,9 @@ describe('Transaction', () => {
       expect(tx.publicKey).not.toBeNull();
 
       // Signature is 64 bytes (ED25519_ACCOUNT)
-      const sig = tx.signature as Uint8Array;
-      expect(sig.length).toBe(64);
+      expect(tx.signature?.rawBytes().length).toBe(64);
       // Public key is 32 bytes (ED25519_ACCOUNT)
-      const pub = tx.publicKey as Uint8Array;
-      expect(pub.length).toBe(32);
+      expect(tx.publicKey?.rawBytes().length).toBe(32);
 
       // Transaction ID
       expect(bytesToHex(tx.id())).toBe(expectedTxId);
@@ -98,11 +97,9 @@ describe('Transaction', () => {
       expect(tx.publicKey).not.toBeNull();
 
       // Signature is 64 bytes (ED25519_ACCOUNT)
-      const sig = tx.signature as Uint8Array;
-      expect(sig.length).toBe(64);
+      expect(tx.signature?.rawBytes().length).toBe(64);
       // Public key is 32 bytes (ED25519_ACCOUNT)
-      const pub = tx.publicKey as Uint8Array;
-      expect(pub.length).toBe(32);
+      expect(tx.publicKey?.rawBytes().length).toBe(32);
 
       // Transaction ID
       expect(bytesToHex(tx.id())).toBe(expectedTxId);
@@ -138,17 +135,43 @@ describe('Transaction', () => {
     });
   });
 
-  describe('sign', () => {
-    it('should throw error when sign is called', () => {
+  describe('sign and verify', () => {
+    it('should sign and verify a transaction with round-trip', () => {
+      const privKey = Ed25519PrivateKey.random();
+      const pubKey = privKey.publicKey();
+      const sender = pubKey.accountAddress();
+      const receiver = Address.fromString('pc1r0g22ufzn8qtw0742dmfglnw73e260hep0k3yra');
       const lockTime = new Height(0);
-      const sender = Address.fromString('pc1z5x2a0lkt5nrrdqe0rkcv6r4pfkmdhrr3mawvua');
-      const receiver = Address.fromString('pc1zt6qcdymkk48c5ds0fzfsaf6puwu8w8djn3ffpn');
       const amount = Amount.zero();
       const fee = Amount.zero();
 
       const tx = Transaction.createTransferTx(lockTime, sender, receiver, amount, fee);
 
-      expect(() => tx.sign()).toThrow('signing is not supported in the TypeScript SDK');
+      // Unsigned tx should not have sig/pubKey
+      expect(tx.signature).toBeNull();
+      expect(tx.publicKey).toBeNull();
+
+      // Mark as unsigned and sign
+      tx.flags = FLAG_NOT_SIGNED;
+      tx.sign(privKey);
+
+      expect(tx.signature).not.toBeNull();
+      expect(tx.publicKey).not.toBeNull();
+      expect(tx.verify()).toBe(true);
+
+      // Encode signed tx
+      const w = new Writer();
+
+      tx.encode(w);
+      const signedBytes = w.toBytes();
+
+      // Decode round-trip
+      const decoded = Transaction.decode(new Reader(signedBytes));
+
+      expect(decoded.flags).toBe(0);
+      expect(decoded.signature).not.toBeNull();
+      expect(decoded.publicKey).not.toBeNull();
+      expect(decoded.verify()).toBe(true);
     });
   });
 });