refactor!: separate hashing functions into new subproject (#632)

Author: ianbotsf

.changes/d4678053-b78b-486c-a2b3-8029ee5590bd.json

@@ -0,0 +1,5 @@
+{
+    "id": "d4678053-b78b-486c-a2b3-8029ee5590bd",
+    "type": "misc",
+    "description": "Refactor hashing functions into new subproject"
+}

gradle.properties

@@ -5,7 +5,7 @@ kotlin.mpp.stability.nowarn=true
 kotlin.native.ignoreDisabledTargets=true
 
 # SDK
-sdkVersion=0.8.6-SNAPSHOT
+sdkVersion=0.9.0-SNAPSHOT
 
 # kotlin
 kotlinVersion=1.6.10

runtime/hashing/build.gradle.kts

@@ -0,0 +1,22 @@
+/*
+ * Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
+ * SPDX-License-Identifier: Apache-2.0.
+ */
+
+description = "Hashing functions for Smithy services generated by smithy-kotlin"
+extra["displayName"] = "Smithy :: Kotlin :: Hashing"
+extra["moduleName"] = "aws.smithy.kotlin.runtime.hashing"
+
+kotlin {
+    sourceSets {
+        commonMain {
+            dependencies {
+                implementation(project(":runtime:utils"))
+            }
+        }
+
+        all {
+            languageSettings.optIn("aws.smithy.kotlin.runtime.util.InternalApi")
+        }
+    }
+}

runtime/hashing/common/src/aws/smithy/kotlin/runtime/hashing/Crc32.kt

@@ -0,0 +1,28 @@
+/*
+ * Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
+ * SPDX-License-Identifier: Apache-2.0.
+ */
+package aws.smithy.kotlin.runtime.hashing
+
+import aws.smithy.kotlin.runtime.util.InternalApi
+
+@InternalApi
+abstract class Crc32Base : HashFunction {
+    override val blockSizeBytes: Int = 4
+    override val digestSizeBytes: Int = 4
+
+    abstract fun digestValue(): UInt
+}
+
+/**
+ * CRC-32 checksum. Note: [digest] will return the bytes (big endian) of the CRC32 integer value. Access [digestValue]
+ * directly to avoid doing the integer conversion yourself.
+ */
+@InternalApi
+expect class Crc32() : Crc32Base
+
+/**
+ * Compute the MD5 hash of the current [ByteArray]
+ */
+@InternalApi
+fun ByteArray.crc32(): UInt = Crc32().apply { update(this@crc32) }.digestValue()

runtime/hashing/common/src/aws/smithy/kotlin/runtime/hashing/HashFunction.kt

@@ -0,0 +1,59 @@
+/*
+ * Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
+ * SPDX-License-Identifier: Apache-2.0.
+ */
+package aws.smithy.kotlin.runtime.hashing
+
+import aws.smithy.kotlin.runtime.util.InternalApi
+
+/**
+ * A cryptographic hash function (algorithm)
+ */
+@InternalApi
+interface HashFunction {
+    /**
+     * The size of the hashing block in bytes.
+     */
+    val blockSizeBytes: Int
+
+    /**
+     * The size of the digest output in bytes.
+     */
+    val digestSizeBytes: Int
+
+    /**
+     * Update the running hash with [input] bytes. This can be called multiple times.
+     */
+    fun update(input: ByteArray)
+
+    /**
+     * Finalize the hash computation and return the digest bytes. The hash function will be [reset] after the call is
+     * made.
+     */
+    fun digest(): ByteArray
+
+    /**
+     * Resets the digest to its initial state discarding any accumulated digest state.
+     */
+    fun reset()
+}
+
+internal fun hash(fn: HashFunction, input: ByteArray): ByteArray = fn.apply { update(input) }.digest()
+
+/**
+ * Compute a hash of the current [ByteArray]
+ */
+@InternalApi
+fun ByteArray.hash(fn: HashFunction): ByteArray = hash(fn, this)
+
+/**
+ * A function that returns a new instance of a [HashFunction].
+ */
+@InternalApi
+typealias HashSupplier = () -> HashFunction
+
+/**
+ * Compute a hash of the current [ByteArray]
+ */
+@InternalApi
+fun ByteArray.hash(hashSupplier: HashSupplier): ByteArray = hash(hashSupplier(), this)

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

@@ -0,0 +1,25 @@
+/*
+ * Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
+ * SPDX-License-Identifier: Apache-2.0.
+ */
+package aws.smithy.kotlin.runtime.hashing
+
+import aws.smithy.kotlin.runtime.util.InternalApi
+
+@InternalApi
+abstract class Md5Base : HashFunction {
+    override val blockSizeBytes: Int = 64
+    override val digestSizeBytes: Int = 16
+}
+
+/**
+ * Implementation of RFC1321 MD5 digest
+ */
+@InternalApi
+expect class Md5() : Md5Base
+
+/**
+ * Compute the MD5 hash of the current [ByteArray]
+ */
+@InternalApi
+fun ByteArray.md5(): ByteArray = hash(Md5(), this)

runtime/hashing/common/src/aws/smithy/kotlin/runtime/hashing/Sha1.kt

@@ -0,0 +1,25 @@
+/*
+ * Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
+ * SPDX-License-Identifier: Apache-2.0.
+ */
+package aws.smithy.kotlin.runtime.hashing
+
+import aws.smithy.kotlin.runtime.util.InternalApi
+
+@InternalApi
+abstract class Sha1Base : HashFunction {
+    override val blockSizeBytes: Int = 64
+    override val digestSizeBytes: Int = 20
+}
+
+/**
+ * Implementation of SHA-1 (Secure Hash Algorithm 1) hash function. See: https://csrc.nist.gov/projects/hash-functions
+ */
+@InternalApi
+expect class Sha1() : Sha1Base
+
+/**
+ * Compute the SHA-1 hash of the current [ByteArray]
+ */
+@InternalApi
+fun ByteArray.sha1(): ByteArray = hash(Sha1(), this)

runtime/hashing/common/src/aws/smithy/kotlin/runtime/hashing/Sha256.kt

@@ -0,0 +1,26 @@
+/*
+ * Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
+ * SPDX-License-Identifier: Apache-2.0.
+ */
+package aws.smithy.kotlin.runtime.hashing
+
+import aws.smithy.kotlin.runtime.util.InternalApi
+
+@InternalApi
+abstract class Sha256Base : HashFunction {
+    override val blockSizeBytes: Int = 64
+    override val digestSizeBytes: Int = 32
+}
+
+/**
+ * Implementation of NIST SHA-256 hash function. See: https://csrc.nist.gov/projects/hash-functions
+
+ */
+@InternalApi
+expect class Sha256() : Sha256Base
+
+/**
+ * Compute the SHA-256 hash of the current [ByteArray]
+ */
+@InternalApi
+fun ByteArray.sha256(): ByteArray = hash(Sha256(), this)

runtime/utils/common/test/aws/smithy/kotlin/runtime/util/Crc32Test.kt renamed to runtime/hashing/common/test/aws/smithy/kotlin/runtime/hashing/Crc32Test.kt

@@ -2,8 +2,7 @@
  * Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
  * SPDX-License-Identifier: Apache-2.0.
  */
-
-package aws.smithy.kotlin.runtime.util
+package aws.smithy.kotlin.runtime.hashing
 
 import kotlin.test.Test
 import kotlin.test.assertEquals

runtime/utils/common/test/aws/smithy/kotlin/runtime/util/MD5Test.kt renamed to runtime/hashing/common/test/aws/smithy/kotlin/runtime/hashing/Md5Test.kt

@@ -2,25 +2,23 @@
  * Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
  * SPDX-License-Identifier: Apache-2.0.
  */
+package aws.smithy.kotlin.runtime.hashing
 
-package aws.smithy.kotlin.runtime.util
-
+import aws.smithy.kotlin.runtime.util.encodeToHex
 import kotlin.test.Test
 import kotlin.test.assertContentEquals
 import kotlin.test.assertEquals
 
-/**
- * Test vectors from https://www.ietf.org/rfc/rfc1321.txt
- */
-class MD5Test {
+class Md5Test {
+    // Test vectors from https://www.ietf.org/rfc/rfc1321.txt
     private val tests = listOf(
         "" to "d41d8cd98f00b204e9800998ecf8427e",
         "a" to "0cc175b9c0f1b6a831c399e269772661",
         "abc" to "900150983cd24fb0d6963f7d28e17f72",
         "message digest" to "f96b697d7cb7938d525a2f31aaf161d0",
         "abcdefghijklmnopqrstuvwxyz" to "c3fcd3d76192e4007dfb496cca67e13b",
         "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789" to "d174ab98d277d9f5a5611c2c9f419d9f",
-        "12345678901234567890123456789012345678901234567890123456789012345678901234567890" to "57edf4a22be3c955ac49da2e2107b67a"
+        "12345678901234567890123456789012345678901234567890123456789012345678901234567890" to "57edf4a22be3c955ac49da2e2107b67a",
     )
 
     @Test
@@ -33,7 +31,6 @@ class MD5Test {
 
     @Test
     fun testKnownCollision() {
-
         val message1 = intArrayOf(
             0xd1, 0x31, 0xdd, 0x02, 0xc5, 0xe6, 0xee, 0xc4, 0x69, 0x3d, 0x9a, 0x06, 0x98, 0xaf, 0xf9, 0x5c,
             0x2f, 0xca, 0xb5, 0x87, 0x12, 0x46, 0x7e, 0xab, 0x40, 0x04, 0x58, 0x3e, 0xb8, 0xfb, 0x7f, 0x89,