CryptoUtil + AwsKms client for encryption/decryption

diff --git a/common/build.gradle b/common/build.gradle
index 38f2393..7a13c39 100644
--- a/common/build.gradle
+++ b/common/build.gradle

@@ -55,7 +55,10 @@
     compile group: 'com.fasterxml.jackson.core', name: 'jackson-annotations', version: '2.9.4'
     compile group: 'com.fasterxml.jackson.module', name: 'jackson-module-kotlin', version: '2.9.8'
     compile group: 'commons-validator', name: 'commons-validator', version: '1.6'
-    compile group: 'software.amazon.awssdk', name: 's3', version: '2.5.23'
+
+    compile group: 'software.amazon.awssdk', name: 's3', version: '2.6.5'
+    compile group: 'software.amazon.awssdk', name: 'kms', version: '2.6.5'
+
 
     compile "org.jetbrains.kotlin:kotlin-stdlib-jdk8"
     compile "org.jetbrains.kotlin:kotlin-reflect"

diff --git a/common/src/main/kotlin/org/apache/amaterasu/common/crypto/AwsKmsCryptoProvider.kt b/common/src/main/kotlin/org/apache/amaterasu/common/crypto/AwsKmsCryptoProvider.kt
new file mode 100644
index 0000000..ef042e0
--- /dev/null
+++ b/common/src/main/kotlin/org/apache/amaterasu/common/crypto/AwsKmsCryptoProvider.kt

@@ -0,0 +1,53 @@
+package org.apache.amaterasu.common.crypto
+
+import com.amazonaws.services.identitymanagement.model.AccessKey
+import software.amazon.awssdk.auth.credentials.AwsBasicCredentials
+import software.amazon.awssdk.auth.credentials.AwsCredentialsProvider
+import software.amazon.awssdk.auth.credentials.InstanceProfileCredentialsProvider
+import software.amazon.awssdk.auth.credentials.StaticCredentialsProvider
+import software.amazon.awssdk.core.SdkBytes
+import software.amazon.awssdk.services.kms.KmsClient
+import software.amazon.awssdk.services.kms.model.DecryptRequest
+import software.amazon.awssdk.services.kms.model.EncryptRequest
+import software.amazon.awssdk.regions.Region
+
+class AwsKmsCryptoProvider(override val accessKeyId: String,
+                           override val secretAccessKey: String,
+                           override val region: String) : CryptoKeyProvider {
+
+    private var credentials: AwsCredentialsProvider = if (accessKeyId.isNotEmpty()) {
+        StaticCredentialsProvider.create(AwsBasicCredentials.create(accessKeyId, secretAccessKey))
+    } else {
+        InstanceProfileCredentialsProvider.builder().build()
+    }
+
+    val kmsClient = KmsClient.builder().apply {
+        credentialsProvider(credentials)
+        region(Region.of(region))
+    }.build()
+
+    override fun decryptKey(cipherText: ByteArray): String {
+
+        val decryptRequest = DecryptRequest.builder().apply {
+            ciphertextBlob(SdkBytes.fromByteArray(cipherText))
+        }.build()
+
+        val decryptedValue = kmsClient.decrypt(decryptRequest).plaintext()
+
+        return decryptedValue.asUtf8String()
+
+    }
+
+    override fun encryptKey(keyId: String, value: String): ByteArray? {
+
+        val encryptRequest = EncryptRequest.builder().apply {
+            keyId(keyId)
+            plaintext(SdkBytes.fromUtf8String(value))
+        }.build()
+
+        val encryptResponse = kmsClient.encrypt(encryptRequest)
+
+        return encryptResponse.ciphertextBlob().asByteArray()
+    }
+
+}
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diff --git a/common/src/main/kotlin/org/apache/amaterasu/common/crypto/CryptoKeyProvider.kt b/common/src/main/kotlin/org/apache/amaterasu/common/crypto/CryptoKeyProvider.kt
new file mode 100644
index 0000000..dfa80bb
--- /dev/null
+++ b/common/src/main/kotlin/org/apache/amaterasu/common/crypto/CryptoKeyProvider.kt

@@ -0,0 +1,13 @@
+package org.apache.amaterasu.common.crypto
+
+interface CryptoKeyProvider {
+
+    val accessKeyId: String
+    val secretAccessKey: String
+    val region: String
+
+    fun decryptKey(cipherText: ByteArray): String
+
+    fun encryptKey(keyId: String, value: String): ByteArray?
+
+}
\ No newline at end of file

diff --git a/common/src/main/kotlin/org/apache/amaterasu/common/utils/CryptoUtils.kt b/common/src/main/kotlin/org/apache/amaterasu/common/utils/CryptoUtils.kt
new file mode 100644
index 0000000..599996f
--- /dev/null
+++ b/common/src/main/kotlin/org/apache/amaterasu/common/utils/CryptoUtils.kt

@@ -0,0 +1,15 @@
+package org.apache.amaterasu.common.utils
+
+import org.apache.amaterasu.common.crypto.CryptoKeyProvider
+
+class CryptoUtils(private val keyProvider: CryptoKeyProvider) {
+
+    fun decryptKey(encryptedKey: ByteArray): String {
+        return keyProvider.decryptKey(encryptedKey)
+    }
+
+    fun encryptKey(keyId: String, value: String): ByteArray? {
+        return keyProvider.encryptKey(keyId, value)
+    }
+
+}
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diff --git a/common/src/test/kotlin/org/apache/amaterasu/common/utils/CryptoUtilsTest.kt b/common/src/test/kotlin/org/apache/amaterasu/common/utils/CryptoUtilsTest.kt
new file mode 100644
index 0000000..2cd23cb
--- /dev/null
+++ b/common/src/test/kotlin/org/apache/amaterasu/common/utils/CryptoUtilsTest.kt

@@ -0,0 +1,33 @@
+package org.apache.amaterasu.common.utils
+
+import org.apache.amaterasu.common.crypto.AwsKmsCryptoProvider
+import org.jetbrains.spek.api.Spek
+import org.jetbrains.spek.api.dsl.given
+import org.jetbrains.spek.api.dsl.it
+import org.jetbrains.spek.api.dsl.on
+import org.junit.Assert.*
+
+
+//class CryptoUtilsTest : Spek({
+//
+//    given("an aws key and value") {
+//        val keyId = "arn:aws:kms:"
+//        val clearText = "Value to encrypt"
+//
+//        on ("encrypting and decrypting") {
+//
+//            val kmsClient = CryptoUtils(AwsKmsCryptoProvider(
+//                    accessKeyId = "",
+//                    secretAccessKey = "",
+//                    region = "ap-southeast-2"))
+//            val encryptedText = kmsClient.encryptKey(keyId, clearText)!!
+//
+//            val decryptedText = kmsClient.decryptKey(encryptedText)
+//
+//            it("decrypted value is the same as the clear text") {
+//                assertEquals(clearText, decryptedText)
+//            }
+//        }
+//    }
+//
+//})
\ No newline at end of file