add support for md5 checksum validation

Author: xinsong-cui

runtime/runtime-core/api/runtime-core.api

@@ -725,6 +725,7 @@ public final class aws/smithy/kotlin/runtime/hashing/Md5 : aws/smithy/kotlin/run
 	public fun <init> ()V
 	public fun digest ()[B
 	public fun reset ()V
+	public final fun update (B)V
 	public fun update ([BII)V
 }
 

runtime/runtime-core/common/src/aws/smithy/kotlin/runtime/config/EnvironmentSetting.kt

@@ -68,3 +68,22 @@ public inline fun <reified T : Enum<T>> enumEnvSetting(sysProp: String, envVar:
     }
     return EnvironmentSetting(parse, sysProp, envVar)
 }
+
+@InternalApi
+public inline fun <reified T : Enum<T>> enumSetEnvSetting(sysProp: String, envVar: String): EnvironmentSetting<Set<T>?> {
+    val parse = { strValue: String ->
+        strValue.split(",")
+            .map { it.trim() }
+            .filter { it.isNotEmpty() }
+            .map { enumValue ->
+                enumValues<T>()
+                    .firstOrNull { it.name.equals(enumValue, ignoreCase = true) }
+                    ?: throw ClientException(
+                        "Value $enumValue is not supported, should be one of ${enumValues<T>().joinToString(", ")}"
+                    )
+            }
+            .toSet()
+            .takeIf { it.isNotEmpty() }
+    }
+    return EnvironmentSetting(parse, sysProp, envVar)
+}

runtime/runtime-core/common/src/aws/smithy/kotlin/runtime/hashing/Md5.kt

@@ -18,6 +18,7 @@ public abstract class Md5Base : HashFunction {
 @InternalApi
 public expect class Md5() : Md5Base {
     override fun update(input: ByteArray, offset: Int, length: Int)
+    public fun update(input: Byte)
     override fun digest(): ByteArray
     override fun reset()
     override val blockSizeBytes: Int

runtime/runtime-core/jvm/src/aws/smithy/kotlin/runtime/hashing/Md5JVM.kt

@@ -11,6 +11,7 @@ import java.security.MessageDigest
 public actual class Md5 : Md5Base() {
     private val md = MessageDigest.getInstance("MD5")
     actual override fun update(input: ByteArray, offset: Int, length: Int): Unit = md.update(input, offset, length)
+    public actual fun update(input: Byte): Unit = md.update(input)
     actual override fun digest(): ByteArray = md.digest()
     actual override fun reset(): Unit = md.reset()
 }

runtime/runtime-core/native/src/aws/smithy/kotlin/runtime/hashing/Md5Native.kt

@@ -15,6 +15,10 @@ public actual class Md5 actual constructor() : Md5Base() {
         TODO("Not yet implemented")
     }
 
+    public actual fun update(input: Byte) {
+        TODO("Not yet implemented")
+    }
+
     actual override fun digest(): ByteArray {
         TODO("Not yet implemented")
     }