feat<descriptor>: added key derivation functions in KeyProvider class

bcoin-org · Jul 30, 2023 · ca83bdd · ca83bdd
1 parent 014a104
commit ca83bdd
Showing 1 changed file with 100 additions and 1 deletion.
diff --git a/lib/descriptor/keyprovider.js b/lib/descriptor/keyprovider.js
@@ -263,6 +263,24 @@ class KeyProvider {
   hasPrivateKey() {
     return this.ring.privateKey !== null;
   }
+
+  /**
+   * Get the public key
+   * @returns {Buffer}
+   */
+
+  getPublicKey() {
+    return this.ring.publicKey;
+  }
+
+  /**
+   * Get the private key (if available)
+   * @returns {Buffer}
+   */
+
+  getPrivateKey() {
+    return this.ring.privateKey;
+  }
 }
 
 /**
@@ -407,6 +425,87 @@ class HDKeyProvider extends KeyProvider {
     }
     return null;
   }
+
+  /**
+   * Derive private key at a given position..
+   * @returns {HDPrivateKey}
+   */
+
+  getHDPrivateKey(pos) {
+    assert(
+      this.hdkey.privateKey,
+      'Private key not available for hardened derivation.'
+    );
+
+    let childkey = this.hdkey;
+
+    if (this.path.length > 0) {
+      const path = 'm' + HD.common.format(this.path, this.hardenedMarker);
+      childkey = childkey.derivePath(path);
+    }
+
+    if (this.type === deriveType.UNHARDENED) {
+      childkey = childkey.derive(pos, false);
+    } else if (this.type === deriveType.HARDENED) {
+      childkey = childkey.derive(pos, true);
+    }
+
+    return childkey;
+  }
+
+  /**
+   * Derive public key at a given position
+   * @param {Number} pos
+   * @returns {HDPublicKey}
+   */
+
+  getHDPublicKey(pos) {
+    if (this.isHardened()) {
+      const childprivkey = this.getHDPrivateKey(pos);
+      return childprivkey.toPublic();
+    }
+
+    let childkey = this.hdkey;
+
+    if (this.hdkey instanceof HD.PrivateKey) {
+      childkey = this.hdkey.toPublic();
+    }
+
+    if (this.path.length > 0) {
+      const path = 'm' + HD.common.format(this.path, this.hardenedMarker);
+      childkey = childkey.derivePath(path);
+    }
+
+    if (this.type === deriveType.UNHARDENED) {
+      childkey = childkey.derive(pos);
+    }
+
+    assert(this.type !== deriveType.HARDENED);
+
+    return childkey;
+  }
+
+  /**
+   * Get public key at a given position
+   * @param {Number} pos
+   * @returns {Buffer} public key
+   */
+
+  getPublicKey(pos) {
+    const hdkey = this.getHDPublicKey(pos);
+    return hdkey.publicKey;
+  }
+
+  /**
+   * Get private key at a given position
+   * @param {Number} pos
+   * @returns {Buffer} private key
+   */
+
+  getPrivateKey(pos) {
+    const hdkey = this.getHDPrivateKey(pos);
+    return hdkey.privateKey;
+  }
 }
 
 /**
@@ -424,7 +523,7 @@ function getHardenedMarker(path) {
 
   let hardenedMarker = null;
   for (const p of path) {
-   const last = p[p.length - 1];
+    const last = p[p.length - 1];
     if (last === '\'' || last === 'h') {
       hardenedMarker = last;
     }