From 2b7d98a9bd1297cbd3a18b6074fb83598d241410 Mon Sep 17 00:00:00 2001
From: Loris Leiva <loris.leiva@gmail.com>
Date: Fri, 2 Aug 2024 15:42:58 +0100
Subject: [PATCH] Add createKeyPairSignerFromPrivateKeyBytes helper

---
 .changeset/dry-glasses-roll.md         |  5 +++++
 packages/signers/README.md             | 30 ++++++++++++++++++++++++++
 packages/signers/src/keypair-signer.ts | 10 ++++++++-
 3 files changed, 44 insertions(+), 1 deletion(-)
 create mode 100644 .changeset/dry-glasses-roll.md

diff --git a/.changeset/dry-glasses-roll.md b/.changeset/dry-glasses-roll.md
new file mode 100644
index 000000000000..c36beea7ff86
--- /dev/null
+++ b/.changeset/dry-glasses-roll.md
@@ -0,0 +1,5 @@
+---
+'@solana/signers': patch
+---
+
+Add a `createKeyPairSignerFromPrivateKeyBytes` helper that compose `createKeyPairFromPrivateKeyBytes` and `createSignerFromKeyPair`.
diff --git a/packages/signers/README.md b/packages/signers/README.md
index 4075fd182083..d77bd4fb6c8b 100644
--- a/packages/signers/README.md
+++ b/packages/signers/README.md
@@ -316,6 +316,36 @@ import { generateKeyPairSigner } from '@solana/signers';
 const myKeyPairSigner = await generateKeyPairSigner();
 ```
 
+#### `createKeyPairSignerFromBytes()`
+
+A convenience function that creates a new KeyPair from a 64-bytes `Uint8Array` secret key and immediately creates a `KeyPairSigner` from it.
+
+```ts
+import fs from 'fs';
+import { createKeyPairFromBytes } from '@solana/keys';
+
+// Get bytes from local keypair file.
+const keypairFile = fs.readFileSync('~/.config/solana/id.json');
+const keypairBytes = new Uint8Array(JSON.parse(keypairFile.toString()));
+
+// Create a KeyPairSigner from the bytes.
+const { privateKey, publicKey } = await createKeyPairSignerFromBytes(keypairBytes);
+```
+
+#### `createKeyPairSignerFromPrivateKeyBytes()`
+
+A convenience function that creates a new KeyPair from a 32-bytes `Uint8Array` private key and immediately creates a `KeyPairSigner` from it.
+
+```ts
+import { getUtf8Encoder } from '@solana/codecs-strings';
+import { createKeyPairFromPrivateKeyBytes } from '@solana/keys';
+
+const message = getUtf8Encoder().encode('Hello, World!');
+const seed = new Uint8Array(await crypto.subtle.digest('SHA-256', message));
+
+const derivedSigner = await createKeyPairSignerFromPrivateKeyBytes(seed);
+```
+
 #### `isKeyPairSigner()`
 
 A type guard that returns `true` if the provided value is a `KeyPairSigner`.
diff --git a/packages/signers/src/keypair-signer.ts b/packages/signers/src/keypair-signer.ts
index 97ee97faf218..80ab07ffcbf0 100644
--- a/packages/signers/src/keypair-signer.ts
+++ b/packages/signers/src/keypair-signer.ts
@@ -1,7 +1,7 @@
 import { Address, getAddressFromPublicKey } from '@solana/addresses';
 import { ReadonlyUint8Array } from '@solana/codecs-core';
 import { SOLANA_ERROR__SIGNER__EXPECTED_KEY_PAIR_SIGNER, SolanaError } from '@solana/errors';
-import { createKeyPairFromBytes, generateKeyPair, signBytes } from '@solana/keys';
+import { createKeyPairFromBytes, createKeyPairFromPrivateKeyBytes, generateKeyPair, signBytes } from '@solana/keys';
 import { partiallySignTransaction } from '@solana/transactions';
 
 import { isMessagePartialSigner, MessagePartialSigner } from './message-partial-signer';
@@ -73,3 +73,11 @@ export async function createKeyPairSignerFromBytes(
 ): Promise<KeyPairSigner> {
     return await createSignerFromKeyPair(await createKeyPairFromBytes(bytes, extractable));
 }
+
+/** Creates a signer capable of signing messages and transactions using the 32 bytes of a private key. */
+export async function createKeyPairSignerFromPrivateKeyBytes(
+    bytes: ReadonlyUint8Array,
+    extractable?: boolean,
+): Promise<KeyPairSigner> {
+    return await createSignerFromKeyPair(await createKeyPairFromPrivateKeyBytes(bytes, extractable));
+}