Add StandardAccount.generatePrivateKey() (#507)

software-mansion · Aug 29, 2024 · 56d1665 · 56d1665
1 parent 2bae98e
commit 56d1665
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diff --git a/lib/src/main/kotlin/com/swmansion/starknet/account/StandardAccount.kt b/lib/src/main/kotlin/com/swmansion/starknet/account/StandardAccount.kt
@@ -11,6 +11,7 @@ import com.swmansion.starknet.provider.exceptions.RequestFailedException
 import com.swmansion.starknet.signer.Signer
 import com.swmansion.starknet.signer.StarkCurveSigner
 import java.math.BigInteger
+import java.security.SecureRandom
 import java.util.concurrent.CompletableFuture
 
 /**
@@ -97,6 +98,21 @@ class StandardAccount @JvmOverloads constructor(
             val contract = provider.getClassAt(address).send()
             return if (contract is ContractClass) CairoVersion.ONE else CairoVersion.ZERO
         }
+
+        /**
+         * Generate a random private key.
+         *
+         * @return private key
+         */
+        @JvmStatic
+        fun generatePrivateKey(): Felt {
+            val random = SecureRandom()
+            val randomBytes = ByteArray(32)
+            random.nextBytes(randomBytes)
+            val randomInt = BigInteger(1, randomBytes)
+            val privateKey = randomInt % Felt.PRIME
+            return privateKey.toFelt
+        }
     }
 
     override fun signV1(calls: List<Call>, params: ExecutionParams, forFeeEstimate: Boolean): InvokeTransactionV1Payload {

diff --git a/lib/src/test/kotlin/starknet/account/StandardAccountTest.kt b/lib/src/test/kotlin/starknet/account/StandardAccountTest.kt
@@ -88,6 +88,13 @@ class StandardAccountTest {
         StandardAccount(Felt.ZERO, privateKey, provider, chainId)
     }
 
+    @Test
+    fun `generate random private key`() {
+        val randomPrivateKey = StandardAccount.generatePrivateKey()
+        assertTrue(randomPrivateKey.value < Felt.PRIME)
+        assertTrue(randomPrivateKey.hexStringPadded().length == 66)
+    }
+
     @Test
     fun `cairo 0 account with automatic version detection`() {
         val call = Call(

diff --git a/lib/starknet-jvm.md b/lib/starknet-jvm.md
@@ -156,6 +156,10 @@ public class Main {
 
         // Create an account interface
         Felt privateKey = Felt.fromHex("0x123");
+
+        // You can also generate a random private key
+         Felt randomPrivateKey = StarknetCurve.generatePrivateKey();
+
         Felt publicKey = StarknetCurve.getPublicKey(privateKey);
 
         // Use the class hash of the desired account contract (i.e. the class hash of OpenZeppelin account contract)