js EdHDKey + external

apollo/src/allButJSMain/kotlin/io/iohk/atala/prism/apollo/derivation/EdHDKey.kt

@@ -1,19 +1,13 @@
 package io.iohk.atala.prism.apollo.derivation
 
-import com.ionspin.kotlin.bignum.integer.BigInteger
 import com.ionspin.kotlin.bignum.integer.toBigInteger
 import ed25519_bip32.XPrvWrapper
 import io.iohk.atala.prism.apollo.utils.ECConfig
-import kotlin.js.ExperimentalJsExport
-import kotlin.js.JsExport
-import kotlin.js.JsName
 
 
 /**
  * Represents and HDKey with its derive methods
  */
-@OptIn(ExperimentalJsExport::class)
-@JsExport
 class EdHDKey(
     val privateKey: ByteArray,
     val chainCode: ByteArray,
@@ -22,15 +16,11 @@ class EdHDKey(
     val index: BigIntegerWrapper = BigIntegerWrapper(0)
 ) {
     /**
-     * Constructs a new EdHDKey object from a seed, depth, and child index.
+     * Constructs a new EdHDKey object from a seed
      *
      * @param seed The seed used to derive the private key and chain code.
-     * @param depth The depth of the HDKey.
-     * @param childIndex The child index of the HDKey.
-     *
      * @throws IllegalArgumentException if the seed length is not equal to 64.
      */
-
     fun initFromSeed(seed: ByteArray): EdHDKey {
         require(seed.size == 64) {
             "Seed expected byte length to be ${ECConfig.PRIVATE_KEY_BYTE_SIZE}"

apollo/src/jsMain/kotlin/io/iohk/atala/prism/apollo/derivation/EdHDKey.kt

@@ -0,0 +1,88 @@
+package io.iohk.atala.prism.apollo.derivation
+
+import com.ionspin.kotlin.bignum.integer.toBigInteger
+import io.iohk.atala.prism.apollo.utils.ECConfig
+import io.iohk.atala.prism.apollo.utils.external.ed25519_bip32
+
+/**
+ * Represents and HDKey with its derive methods
+ */
+@OptIn(ExperimentalJsExport::class)
+@JsExport
+class EdHDKey(
+    val privateKey: ByteArray,
+    val chainCode: ByteArray,
+    val publicKey: ByteArray? = null,
+    val depth: Int = 0,
+    val index: BigIntegerWrapper = BigIntegerWrapper(0)
+) {
+    /**
+     * Constructs a new EdHDKey object from a seed
+     *
+     * @param seed The seed used to derive the private key and chain code.
+     * @throws IllegalArgumentException if the seed length is not equal to 64.
+     */
+    fun initFromSeed(seed: ByteArray): EdHDKey {
+        require(seed.size == 64) {
+            "Seed expected byte length to be ${ECConfig.PRIVATE_KEY_BYTE_SIZE}"
+        }
+
+        val key = seed.sliceArray(0 until 32)
+        val chainCode = seed.sliceArray(32 until seed.size)
+        val wrapper = ed25519_bip32.XPrvWrapper.from_nonextended_noforce(key, chainCode)
+
+        return EdHDKey(
+            privateKey = wrapper.extended_secret_key(),
+            chainCode = wrapper.chain_code(),
+        )
+    }
+
+    /**
+     * Method to derive an HDKey by a path
+     *
+     * @param path value used to derive a key
+     */
+    fun derive(path: String): EdHDKey {
+        if (!path.matches(Regex("^[mM].*"))) {
+            throw Error("Path must start with \"m\" or \"M\"")
+        }
+        if (Regex("^[mM]'?$").matches(path)) {
+            return this
+        }
+        val parts = path.replace(Regex("^[mM]'?/"), "").split("/")
+        var child = this
+
+        for (c in parts) {
+            val m = Regex("^(\\d+)('?)$").find(c)?.groupValues
+            if (m == null || m.size != 3) {
+                throw Error("Invalid child index: $c")
+            }
+            val idx = m[1].toBigInteger()
+            if (idx >= HDKey.HARDENED_OFFSET) {
+                throw Error("Invalid index")
+            }
+            val finalIdx = if (m[2] == "'") idx + HDKey.HARDENED_OFFSET else idx
+
+            child = child.deriveChild(BigIntegerWrapper(finalIdx))
+        }
+
+        return child
+    }
+
+    /**
+     * Method to derive an HDKey child by index
+     *
+     * @param index value used to derive a key
+     */
+    fun deriveChild(wrappedIndex: BigIntegerWrapper): EdHDKey {
+        val wrapper = ed25519_bip32.XPrvWrapper.from_extended_and_chaincode(privateKey, chainCode)
+        val derived = wrapper.derive(wrappedIndex.value.uintValue())
+
+        return EdHDKey(
+            privateKey = derived.extended_secret_key(),
+            chainCode = derived.chain_code(),
+            depth = depth + 1,
+            index = wrappedIndex
+        )
+    }
+}

apollo/src/jsMain/kotlin/io/iohk/atala/prism/apollo/utils/external/Ed25519_Bip32.kt

@@ -0,0 +1,22 @@
+package io.iohk.atala.prism.apollo.utils.external
+
+external interface XPrvWrapper {
+    fun public(): ByteArray
+
+    fun derive(index: Any): XPrvWrapper
+
+    fun extended_secret_key(): ByteArray
+
+    fun chain_code(): ByteArray
+
+    var from_nonextended_noforce: (js_bytes: ByteArray, js_chain_code: ByteArray) -> XPrvWrapper
+
+    var from_extended_and_chaincode: (js_bytes: ByteArray, js_chain_code: ByteArray) -> XPrvWrapper
+}
+
+external interface ed25519_bip32_export {
+    var XPrvWrapper: XPrvWrapper
+}
+
+@JsModule("ed25519_bip32_export")
+external val ed25519_bip32: ed25519_bip32_export