Initial commit

This initial commit includes HUSH specific changes starting at this commit:
d14637012c

mnemonic/.gitignore

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+/build

mnemonic/build.gradle

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+import cash.z.ecc.android.Deps
+
+apply plugin: 'kotlin'
+
+dependencies {
+    implementation Deps.JavaX.INJECT
+    implementation Deps.Kotlin.STDLIB
+
+    // Zcash
+    implementation Deps.Zcash.ANDROID_WALLET_PLUGINS
+    implementation Deps.Zcash.KOTLIN_BIP39
+
+    testImplementation Deps.Test.JUNIT
+}

mnemonic/src/main/java/cash/z/ecc/kotlin/mnemonic/MnemonicExt.kt

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+package cash.z.ecc.kotlin.mnemonic
+
+import java.util.*
+
+
+/**
+ * Clears out the given char array in memory, for security purposes.
+ */
+fun CharArray.clear() {
+    Arrays.fill(this, '0')
+}
+
+/**
+ * Clears out the given byte array in memory, for security purposes.
+ */
+fun ByteArray.clear() {
+    Arrays.fill(this, 0.toByte())
+}

mnemonic/src/main/java/cash/z/ecc/kotlin/mnemonic/Mnemonics.kt

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+package cash.z.ecc.kotlin.mnemonic
+
+import cash.z.android.plugin.MnemonicPlugin
+import cash.z.ecc.android.bip39.Mnemonics
+import cash.z.ecc.android.bip39.Mnemonics.MnemonicCode
+import cash.z.ecc.android.bip39.Mnemonics.WordCount
+import cash.z.ecc.android.bip39.toEntropy
+import cash.z.ecc.android.bip39.toSeed
+import java.util.*
+import java.util.Locale.ENGLISH
+
+class Mnemonics : MnemonicPlugin {
+    override fun fullWordList(languageCode: String) = Mnemonics.getCachedWords(Locale.ENGLISH.language)
+    override fun nextEntropy(): ByteArray = WordCount.COUNT_24.toEntropy()
+    override fun nextMnemonic(): CharArray = MnemonicCode(WordCount.COUNT_24).chars
+    override fun nextMnemonic(entropy: ByteArray): CharArray = MnemonicCode(entropy).chars
+    override fun nextMnemonicList(): List<CharArray> = MnemonicCode(WordCount.COUNT_24).words
+    override fun nextMnemonicList(entropy: ByteArray): List<CharArray> = MnemonicCode(entropy).words
+    override fun toSeed(mnemonic: CharArray): ByteArray = MnemonicCode(mnemonic).toSeed()
+    override fun toWordList(mnemonic: CharArray): List<CharArray> = MnemonicCode(mnemonic).words
+
+    fun validate(mnemonic: CharArray) {
+        MnemonicCode(mnemonic).validate()
+    }
+}

mnemonic/src/test/java/cash/z/ecc/android/util/MnemonicTest.kt

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+package cash.z.ecc.android.util
+
+import cash.z.android.plugin.MnemonicPlugin
+import cash.z.ecc.kotlin.mnemonic.Mnemonics
+import org.junit.Assert.assertEquals
+import org.junit.Before
+import org.junit.Test
+import java.lang.Math.max
+import java.util.*
+
+
+class MnemonicTest {
+
+    lateinit var mnemonics: MnemonicPlugin
+
+    @Before
+    fun start() {
+        mnemonics = Mnemonics()
+    }
+
+    @Test
+    fun testSeed_fromMnemonic() {
+        val seed = mnemonics.run {
+            toSeed(nextMnemonic())
+        }
+        assertEquals(64, seed.size)
+    }
+
+    @Test
+    fun testMnemonic_create() {
+        val words = String(mnemonics.nextMnemonic()).split(' ')
+        assertEquals(24, words.size)
+        validate(words)
+    }
+
+    @Test
+    fun testMnemonic_createList() {
+        val words = mnemonics.nextMnemonicList()
+        assertEquals(24, words.size)
+        validate(words.map { String(it) })
+    }
+
+    @Test
+    fun testMnemonic_toList() {
+        val words = mnemonics.run {
+            toWordList(nextMnemonic())
+        }
+        assertEquals(24, words.size)
+        validate(words.map { String(it) })
+    }
+
+    @Test
+    fun testMnemonic_longestWord() {
+        var max = 0
+        val englishWordList = mnemonics.fullWordList(Locale.ENGLISH.language)
+        repeat(2048) {
+            max = max(max, englishWordList[it].length)
+        }
+        assertEquals(8, max)
+    }
+
+    private fun validate(words: List<String>) {
+        val englishWordList = mnemonics.fullWordList(Locale.ENGLISH.language)
+        // return or crash!
+        words.forEach { word ->
+            var i = 0
+            while (true) {
+                if (englishWordList[i++] == word) {
+                    println(word)
+                    break
+                }
+
+            }
+        }
+    }
+}
+
+private fun CharSequence.toWords(): List<CharSequence> {
+    return mutableListOf<CharSequence>().let { result ->
+        var index = 0
+        repeat(length) {
+            if (this[it] == ' ') {
+                result.add(subSequence(index, it))
+                index = it + 1
+            }
+        }
+        result.add(subSequence(index, length))
+        result
+    }
+}