AndroidX 数据存储 - AES/CBC/PKCS7 - javax.crypto.IllegalBlockSizeException
AndroidX DataStore - AES/CBC/PKCS7 - javax.crypto.IllegalBlockSizeException
我阅读了 Mark Allison 的 blog post about combining the new Android DataStore，其中使用 Android 密钥库进行了加密。
我使用的是在他的博客中找到的完全相同的 SecretKey 属性 (AES/CBC/PKCS7) 和 Encrypt/Decrypt。
class AesCipherProvider(
private val keyName: String,
private val keyStore: KeyStore,
private val keyStoreName: String
) : CipherProvider {
override val encryptCipher: Cipher
get() = Cipher.getInstance(TRANSFORMATION).apply {
init(Cipher.ENCRYPT_MODE, getOrCreateKey())
}
override fun decryptCipher(iv: ByteArray): Cipher =
Cipher.getInstance(TRANSFORMATION).apply {
init(Cipher.DECRYPT_MODE, getOrCreateKey(), IvParameterSpec(iv))
}
private fun getOrCreateKey(): SecretKey =
(keyStore.getEntry(keyName, null) as? KeyStore.SecretKeyEntry)?.secretKey
?: generateKey()
private fun generateKey(): SecretKey =
KeyGenerator.getInstance(ALGORITHM, keyStoreName)
.apply { init(keyGenParams) }
.generateKey()
private val keyGenParams =
KeyGenParameterSpec.Builder(
keyName,
KeyProperties.PURPOSE_ENCRYPT or KeyProperties.PURPOSE_DECRYPT
).apply {
setBlockModes(BLOCK_MODE)
setEncryptionPaddings(PADDING)
setUserAuthenticationRequired(false)
setRandomizedEncryptionRequired(true)
}.build()
private companion object {
const val ALGORITHM = KeyProperties.KEY_ALGORITHM_AES
const val BLOCK_MODE = KeyProperties.BLOCK_MODE_CBC
const val PADDING = KeyProperties.ENCRYPTION_PADDING_PKCS7
const val TRANSFORMATION = "$ALGORITHM/$BLOCK_MODE/$PADDING"
}
}
class CryptoImpl constructor(private val cipherProvider: CipherProvider) : Crypto {
override fun encrypt(rawBytes: ByteArray, outputStream: OutputStream) {
val cipher = cipherProvider.encryptCipher
val encryptedBytes = cipher.doFinal(rawBytes)
with(outputStream) {
write(cipher.iv.size)
write(cipher.iv)
write(encryptedBytes.size)
write(encryptedBytes)
}
}
override fun decrypt(inputStream: InputStream): ByteArray {
val ivSize = inputStream.read()
val iv = ByteArray(ivSize)
inputStream.read(iv)
val encryptedDataSize = inputStream.read()
val encryptedData = ByteArray(encryptedDataSize)
inputStream.read(encryptedData)
val cipher = cipherProvider.decryptCipher(iv)
return cipher.doFinal(encryptedData)
}
}
我正在使用以下超级简单的 ProtocolBuffer，只有一个 String 字段。
syntax = "proto3";
option java_package = "my.package.model";
message SimpleData {
string text = 1;
}
我正在使用以下代码来测试此实现。
class SecureSimpleDataSerializer(private val crypto: Crypto) :
Serializer<SimpleData> {
override fun readFrom(input: InputStream): SimpleData {
return if (input.available() != 0) {
try {
SimpleData.ADAPTER.decode(crypto.decrypt(input))
} catch (exception: IOException) {
throw CorruptionException("Cannot read proto", exception)
}
} else {
SimpleData("")
}
}
override fun writeTo(t: SimpleData, output: OutputStream) {
crypto.encrypt(SimpleData.ADAPTER.encode(t), output)
}
override val defaultValue: SimpleData = SimpleData()
}
private val simpleDataStore = createDataStore(
fileName = "SimpleDataStoreTest.pb",
serializer = SecureSimpleDataSerializer(
CryptoImpl(
AesCipherProvider(
"SimpleDataKey",
KeyStore.getInstance("AndroidKeyStore").apply { load(null) },
"AndroidKeyStore"
)
)
)
)
当我尝试序列化和反序列化一个简单的 String 时，它按预期工作。
simpleDataStore.updateData { it.copy(text = "simple-string") }
println(simpleDataStore.data.first())
// "simple-string"
然而，当我尝试使用更长的 String 时（注意小于 Proto 的最大尺寸）。
保存有效，但在终止应用程序并重新启动应用程序以检索它崩溃的值时。
simpleDataStore.updateData { it.copy(text = "eyJraWQiOiJyc2ExIiwiYWxnIjoiUlMyNTYifQeyJhdWQiOiJ2cnRudS1zaXRlIiwic3ViIjoiNmRlNjg1MjctNGVjMi00MmUwLTg0YmEtNGU5ZjE3ZTQ4MmY2IiwiaXNzIjoiaHR0cHM6XC9cL2xvZ2luLnZydC5iZSIsInNjb3BlcyI6ImFkZHJlc3Msb3BlbmlkLHByb2ZpbGUsbGVnYWN5aWQsbWlkLGVtYWlsIiwiZXhwIjoxNjEwMjc4OTQ0LCJpYXQiOjE2MTAyNzUzNDQsImp0aSI6Ijc0MDk3MzFiLTg5OGUtNGVmNS1iNWMwLTEzODM2ZWZjN2ZjOCJ9kSkuI9Z0XLLBtfC0SpHA4wV0299ZOd6Xj99hNkemim7fRP1ooCD8YkqbM0hhBKiiYbvhqmfc1NSKYHAehA7Z9c6XluPTIpZkljHIBH7BLd0IGznraUEOMYDh0I2aQKZxxvwV6RlWetdCBUf3KtQuDO7snywbE5jmhzq75Y") }
println(simpleDataStore.data.first())
Process: com.stylingandroid.datastore, PID: 13706
javax.crypto.IllegalBlockSizeException
at android.security.keystore.AndroidKeyStoreCipherSpiBase.engineDoFinal(AndroidKeyStoreCipherSpiBase.java:513)
at javax.crypto.Cipher.doFinal(Cipher.java:2055)
at com.stylingandroid.datastore.security.CryptoImpl.decrypt(Crypto.kt:33)
at com.stylingandroid.datastore.ui.MainActivity$SecureSimpleDataSerializer.readFrom(MainActivity.kt:32)
at com.stylingandroid.datastore.ui.MainActivity$SecureSimpleDataSerializer.readFrom(MainActivity.kt:26)
at androidx.datastore.core.SingleProcessDataStore.readData(SingleProcessDataStore.kt:249)
at androidx.datastore.core.SingleProcessDataStore.readDataOrHandleCorruption(SingleProcessDataStore.kt:227)
at androidx.datastore.core.SingleProcessDataStore.readAndInitOnce(SingleProcessDataStore.kt:190)
at androidx.datastore.core.SingleProcessDataStore$actor.invokeSuspend(SingleProcessDataStore.kt:154)
at kotlin.coroutines.jvm.internal.BaseContinuationImpl.resumeWith(ContinuationImpl.kt:33)
at kotlinx.coroutines.DispatchedTask.run(DispatchedTask.kt:106)
at kotlinx.coroutines.scheduling.CoroutineScheduler.runSafely(CoroutineScheduler.kt:571)
at kotlinx.coroutines.scheduling.CoroutineScheduler$Worker.executeTask(CoroutineScheduler.kt:738)
at kotlinx.coroutines.scheduling.CoroutineScheduler$Worker.runWorker(CoroutineScheduler.kt:678)
at kotlinx.coroutines.scheduling.CoroutineScheduler$Worker.run(CoroutineScheduler.kt:665)
Caused by: android.security.KeyStoreException: Invalid input length
at android.security.KeyStore.getKeyStoreException(KeyStore.java:1301)
at android.security.keystore.KeyStoreCryptoOperationChunkedStreamer.doFinal(KeyStoreCryptoOperationChunkedStreamer.java:176)
at android.security.keystore.AndroidKeyStoreCipherSpiBase.engineDoFinal(AndroidKeyStoreCipherSpiBase.java:506)
at javax.crypto.Cipher.doFinal(Cipher.java:2055)
at com.stylingandroid.datastore.security.CryptoImpl.decrypt(Crypto.kt:33)
at com.stylingandroid.datastore.ui.MainActivity$SecureSimpleDataSerializer.readFrom(MainActivity.kt:32)
at com.stylingandroid.datastore.ui.MainActivity$SecureSimpleDataSerializer.readFrom(MainActivity.kt:26)
at androidx.datastore.core.SingleProcessDataStore.readData(SingleProcessDataStore.kt:249)
at androidx.datastore.core.SingleProcessDataStore.readDataOrHandleCorruption(SingleProcessDataStore.kt:227)
at androidx.datastore.core.SingleProcessDataStore.readAndInitOnce(SingleProcessDataStore.kt:190)
at androidx.datastore.core.SingleProcessDataStore$actor.invokeSuspend(SingleProcessDataStore.kt:154)
at kotlin.coroutines.jvm.internal.BaseContinuationImpl.resumeWith(ContinuationImpl.kt:33)
at kotlinx.coroutines.DispatchedTask.run(DispatchedTask.kt:106)
at kotlinx.coroutines.scheduling.CoroutineScheduler.runSafely(CoroutineScheduler.kt:571)
at kotlinx.coroutines.scheduling.CoroutineScheduler$Worker.executeTask(CoroutineScheduler.kt:738)
at kotlinx.coroutines.scheduling.CoroutineScheduler$Worker.runWorker(CoroutineScheduler.kt:678)
at kotlinx.coroutines.scheduling.CoroutineScheduler$Worker.run(CoroutineScheduler.kt:665)
2021-01-10 14:08:09.907 13706-13706/com.stylingandroid.datastore I/Process: Sending signal. PID: 13706 SIG: 9
有人知道吗？
是否特定于字符串的长度以及所选的加密算法？
是不是解密函数出错了？
提前致谢。
问题在我的机器上重现。当CryptoImpl.encrypt中的加密数据encryptedBytes长度超过255字节时，就会出现这种情况。原因是从256字节开始encryptedBytes.size不能存储在一个字节上，而方法int InputStream.read()或void OutputStream.write(int)只读取或写入一个字节
因此，如果要写入密文的大小，CryptoImpl.encrypt中必须使用足够大的字节缓冲区，例如4 个字节：
with(outputStream) {
write(cipher.iv.size)
write(cipher.iv)
write(ByteBuffer.allocate(4).putInt(encryptedBytes.size).array()) // Convert Int to 4 bytes buffer
write(encryptedBytes)
}
并在 CryptoImpl.decrypt 中阅读：
val ivSize = inputStream.read()
val iv = ByteArray(ivSize)
inputStream.read(iv)
val encryptedDataSizeBytes = ByteArray(4)
inputStream.read(encryptedDataSizeBytes)
val encryptedDataSize = ByteBuffer.wrap(encryptedDataSizeBytes).int // Convert 4 bytes buffer to Int
val encryptedData = ByteArray(encryptedDataSize)
inputStream.read(encryptedData)
然而，实际上没有必要写尺寸。 IV 的大小是已知的，它对应于块大小，即 AES 为 16 字节，因此定义了 IV 和密文分离的标准。这样，CryptoImpl.encrypt中的数据可以这样写：
with(outputStream) {
write(cipher.iv) // Write 16 bytes IV
write(encryptedBytes) // Write ciphertext
}
阅读CryptoImpl.decrypt：
val iv = ByteArray(16)
inputStream.read(iv) // Read IV (first 16 bytes)
val encryptedData = inputStream.readBytes() // Read ciphertext (remaining data)
我阅读了 Mark Allison 的 blog post about combining the new Android DataStore，其中使用 Android 密钥库进行了加密。
我使用的是在他的博客中找到的完全相同的 SecretKey 属性 (AES/CBC/PKCS7) 和 Encrypt/Decrypt。
class AesCipherProvider(
private val keyName: String,
private val keyStore: KeyStore,
private val keyStoreName: String
) : CipherProvider {
override val encryptCipher: Cipher
get() = Cipher.getInstance(TRANSFORMATION).apply {
init(Cipher.ENCRYPT_MODE, getOrCreateKey())
}
override fun decryptCipher(iv: ByteArray): Cipher =
Cipher.getInstance(TRANSFORMATION).apply {
init(Cipher.DECRYPT_MODE, getOrCreateKey(), IvParameterSpec(iv))
}
private fun getOrCreateKey(): SecretKey =
(keyStore.getEntry(keyName, null) as? KeyStore.SecretKeyEntry)?.secretKey
?: generateKey()
private fun generateKey(): SecretKey =
KeyGenerator.getInstance(ALGORITHM, keyStoreName)
.apply { init(keyGenParams) }
.generateKey()
private val keyGenParams =
KeyGenParameterSpec.Builder(
keyName,
KeyProperties.PURPOSE_ENCRYPT or KeyProperties.PURPOSE_DECRYPT
).apply {
setBlockModes(BLOCK_MODE)
setEncryptionPaddings(PADDING)
setUserAuthenticationRequired(false)
setRandomizedEncryptionRequired(true)
}.build()
private companion object {
const val ALGORITHM = KeyProperties.KEY_ALGORITHM_AES
const val BLOCK_MODE = KeyProperties.BLOCK_MODE_CBC
const val PADDING = KeyProperties.ENCRYPTION_PADDING_PKCS7
const val TRANSFORMATION = "$ALGORITHM/$BLOCK_MODE/$PADDING"
}
}
class CryptoImpl constructor(private val cipherProvider: CipherProvider) : Crypto {
override fun encrypt(rawBytes: ByteArray, outputStream: OutputStream) {
val cipher = cipherProvider.encryptCipher
val encryptedBytes = cipher.doFinal(rawBytes)
with(outputStream) {
write(cipher.iv.size)
write(cipher.iv)
write(encryptedBytes.size)
write(encryptedBytes)
}
}
override fun decrypt(inputStream: InputStream): ByteArray {
val ivSize = inputStream.read()
val iv = ByteArray(ivSize)
inputStream.read(iv)
val encryptedDataSize = inputStream.read()
val encryptedData = ByteArray(encryptedDataSize)
inputStream.read(encryptedData)
val cipher = cipherProvider.decryptCipher(iv)
return cipher.doFinal(encryptedData)
}
}
我正在使用以下超级简单的 ProtocolBuffer，只有一个 String 字段。
syntax = "proto3";
option java_package = "my.package.model";
message SimpleData {
string text = 1;
}
我正在使用以下代码来测试此实现。
class SecureSimpleDataSerializer(private val crypto: Crypto) :
Serializer<SimpleData> {
override fun readFrom(input: InputStream): SimpleData {
return if (input.available() != 0) {
try {
SimpleData.ADAPTER.decode(crypto.decrypt(input))
} catch (exception: IOException) {
throw CorruptionException("Cannot read proto", exception)
}
} else {
SimpleData("")
}
}
override fun writeTo(t: SimpleData, output: OutputStream) {
crypto.encrypt(SimpleData.ADAPTER.encode(t), output)
}
override val defaultValue: SimpleData = SimpleData()
}
private val simpleDataStore = createDataStore(
fileName = "SimpleDataStoreTest.pb",
serializer = SecureSimpleDataSerializer(
CryptoImpl(
AesCipherProvider(
"SimpleDataKey",
KeyStore.getInstance("AndroidKeyStore").apply { load(null) },
"AndroidKeyStore"
)
)
)
)
当我尝试序列化和反序列化一个简单的 String 时，它按预期工作。
simpleDataStore.updateData { it.copy(text = "simple-string") }
println(simpleDataStore.data.first())
// "simple-string"
然而，当我尝试使用更长的 String 时（注意小于 Proto 的最大尺寸）。
保存有效，但在终止应用程序并重新启动应用程序以检索它崩溃的值时。
simpleDataStore.updateData { it.copy(text = "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") }
println(simpleDataStore.data.first())
Process: com.stylingandroid.datastore, PID: 13706
javax.crypto.IllegalBlockSizeException
at android.security.keystore.AndroidKeyStoreCipherSpiBase.engineDoFinal(AndroidKeyStoreCipherSpiBase.java:513)
at javax.crypto.Cipher.doFinal(Cipher.java:2055)
at com.stylingandroid.datastore.security.CryptoImpl.decrypt(Crypto.kt:33)
at com.stylingandroid.datastore.ui.MainActivity$SecureSimpleDataSerializer.readFrom(MainActivity.kt:32)
at com.stylingandroid.datastore.ui.MainActivity$SecureSimpleDataSerializer.readFrom(MainActivity.kt:26)
at androidx.datastore.core.SingleProcessDataStore.readData(SingleProcessDataStore.kt:249)
at androidx.datastore.core.SingleProcessDataStore.readDataOrHandleCorruption(SingleProcessDataStore.kt:227)
at androidx.datastore.core.SingleProcessDataStore.readAndInitOnce(SingleProcessDataStore.kt:190)
at androidx.datastore.core.SingleProcessDataStore$actor.invokeSuspend(SingleProcessDataStore.kt:154)
at kotlin.coroutines.jvm.internal.BaseContinuationImpl.resumeWith(ContinuationImpl.kt:33)
at kotlinx.coroutines.DispatchedTask.run(DispatchedTask.kt:106)
at kotlinx.coroutines.scheduling.CoroutineScheduler.runSafely(CoroutineScheduler.kt:571)
at kotlinx.coroutines.scheduling.CoroutineScheduler$Worker.executeTask(CoroutineScheduler.kt:738)
at kotlinx.coroutines.scheduling.CoroutineScheduler$Worker.runWorker(CoroutineScheduler.kt:678)
at kotlinx.coroutines.scheduling.CoroutineScheduler$Worker.run(CoroutineScheduler.kt:665)
Caused by: android.security.KeyStoreException: Invalid input length
at android.security.KeyStore.getKeyStoreException(KeyStore.java:1301)
at android.security.keystore.KeyStoreCryptoOperationChunkedStreamer.doFinal(KeyStoreCryptoOperationChunkedStreamer.java:176)
at android.security.keystore.AndroidKeyStoreCipherSpiBase.engineDoFinal(AndroidKeyStoreCipherSpiBase.java:506)
at javax.crypto.Cipher.doFinal(Cipher.java:2055)
at com.stylingandroid.datastore.security.CryptoImpl.decrypt(Crypto.kt:33)
at com.stylingandroid.datastore.ui.MainActivity$SecureSimpleDataSerializer.readFrom(MainActivity.kt:32)
at com.stylingandroid.datastore.ui.MainActivity$SecureSimpleDataSerializer.readFrom(MainActivity.kt:26)
at androidx.datastore.core.SingleProcessDataStore.readData(SingleProcessDataStore.kt:249)
at androidx.datastore.core.SingleProcessDataStore.readDataOrHandleCorruption(SingleProcessDataStore.kt:227)
at androidx.datastore.core.SingleProcessDataStore.readAndInitOnce(SingleProcessDataStore.kt:190)
at androidx.datastore.core.SingleProcessDataStore$actor.invokeSuspend(SingleProcessDataStore.kt:154)
at kotlin.coroutines.jvm.internal.BaseContinuationImpl.resumeWith(ContinuationImpl.kt:33)
at kotlinx.coroutines.DispatchedTask.run(DispatchedTask.kt:106)
at kotlinx.coroutines.scheduling.CoroutineScheduler.runSafely(CoroutineScheduler.kt:571)
at kotlinx.coroutines.scheduling.CoroutineScheduler$Worker.executeTask(CoroutineScheduler.kt:738)
at kotlinx.coroutines.scheduling.CoroutineScheduler$Worker.runWorker(CoroutineScheduler.kt:678)
at kotlinx.coroutines.scheduling.CoroutineScheduler$Worker.run(CoroutineScheduler.kt:665)
2021-01-10 14:08:09.907 13706-13706/com.stylingandroid.datastore I/Process: Sending signal. PID: 13706 SIG: 9
有人知道吗？
是否特定于字符串的长度以及所选的加密算法？
是不是解密函数出错了？
提前致谢。
问题在我的机器上重现。当CryptoImpl.encrypt中的加密数据encryptedBytes长度超过255字节时，就会出现这种情况。原因是从256字节开始encryptedBytes.size不能存储在一个字节上，而方法int InputStream.read()或void OutputStream.write(int)只读取或写入一个字节
因此，如果要写入密文的大小，CryptoImpl.encrypt中必须使用足够大的字节缓冲区，例如4 个字节：
with(outputStream) {
write(cipher.iv.size)
write(cipher.iv)
write(ByteBuffer.allocate(4).putInt(encryptedBytes.size).array()) // Convert Int to 4 bytes buffer
write(encryptedBytes)
}
并在 CryptoImpl.decrypt 中阅读：
val ivSize = inputStream.read()
val iv = ByteArray(ivSize)
inputStream.read(iv)
val encryptedDataSizeBytes = ByteArray(4)
inputStream.read(encryptedDataSizeBytes)
val encryptedDataSize = ByteBuffer.wrap(encryptedDataSizeBytes).int // Convert 4 bytes buffer to Int
val encryptedData = ByteArray(encryptedDataSize)
inputStream.read(encryptedData)
然而，实际上没有必要写尺寸。 IV 的大小是已知的，它对应于块大小，即 AES 为 16 字节，因此定义了 IV 和密文分离的标准。这样，CryptoImpl.encrypt中的数据可以这样写：
with(outputStream) {
write(cipher.iv) // Write 16 bytes IV
write(encryptedBytes) // Write ciphertext
}
阅读CryptoImpl.decrypt：
val iv = ByteArray(16)
inputStream.read(iv) // Read IV (first 16 bytes)
val encryptedData = inputStream.readBytes() // Read ciphertext (remaining data)