fix: encrypt/decrypt node

modules/decrypt-node/package.json

@@ -24,16 +24,17 @@
     "tslib": "^1.9.3"
   },
   "devDependencies": {
-    "@aws-crypto/encrypt-node": "^0.1.0-preview.1",
     "@types/chai": "^4.1.4",
     "@types/mocha": "^5.2.5",
     "@types/node": "^11.11.4",
     "@typescript-eslint/eslint-plugin": "^1.9.0",
     "@typescript-eslint/parser": "^1.9.0",
+    "@types/from2": "^2.3.0",
     "chai": "^4.1.2",
     "mocha": "^5.2.0",
     "nyc": "^14.0.0",
     "standard": "^12.0.1",
+    "from2": "^2.3.0",
     "ts-node": "^7.0.1",
     "typescript": "^3.5.0"
   },

modules/decrypt-node/src/decipher_stream.ts

@@ -68,9 +68,9 @@ export function getDecipherStream () {
             decipherInfo = info
           })
           .on('BodyInfo', this._onBodyHeader)
-          .on('AuthTag', async (authTag: Buffer) => {
+          .on('AuthTag', async (authTag: Buffer, next: Function) => {
             try {
-              await this._onAuthTag(authTag)
+              await this._onAuthTag(authTag, next)
             } catch (e) {
               this.emit('error', e)
             }
@@ -134,7 +134,7 @@ export function getDecipherStream () {
       super._read(size)
     }
 
-    _onAuthTag = async (authTag: Buffer) => {
+    _onAuthTag = async (authTag: Buffer, next:Function) => {
       const { decipher, content, contentLength } = decipherState
       /* Precondition: _onAuthTag must be called only after a frame has been accumulated.
        * However there is an edge case.  The final frame _can_ be zero length.
@@ -169,6 +169,17 @@ export function getDecipherStream () {
         }
       }
 
+      /* This frame is complete.
+       * Need to notify the VerifyStream continue.
+       * See the note in `AuthTag` for details.
+       * The short answer is that for small frame sizes,
+       * the "next" frame associated auth tag may be
+       * parsed and send before the "current" is processed.
+       * This will cause the auth tag event to fire before
+       * any _transform events fire and a 'Lengths do not match' precondition to fail.
+       */
+      next()
+
       // This frame is complete. Notify _transform to continue, see needs above for more details
       if (frameComplete) frameComplete()
       // reset for next frame.

modules/decrypt-node/src/decrypt.ts

@@ -36,7 +36,7 @@ export interface DecryptOptions {
 
 export async function decrypt (
   cmm: NodeMaterialsManager|KeyringNode,
-  ciphertext: Buffer|Uint8Array|Readable|string,
+  ciphertext: Buffer|Uint8Array|Readable|string|NodeJS.ReadableStream,
   { encoding, maxBodySize } : DecryptOptions = {}
 ): Promise<DecryptOutput> {
   const stream = decryptStream(cmm, { maxBodySize })

modules/decrypt-node/src/verify_stream.ts

@@ -121,8 +121,6 @@ export class VerifyStream extends PortableTransformWithType {
       if (this._verify) {
         this._verify.update(frameBuffer.slice(0, frameHeader.readPos))
       }
-      // clear the buffer.  It _could_ have cipher text...
-      state.buffer = Buffer.alloc(0)
       const tail = chunk.slice(frameHeader.readPos)
       this.emit('BodyInfo', frameHeader)
       state.currentFrame = frameHeader
@@ -155,23 +153,49 @@ export class VerifyStream extends PortableTransformWithType {
         state.authTagBuffer = Buffer.concat([authTagBuffer, chunk])
         return callback()
       } else {
-        state.authTagBuffer = Buffer.concat([authTagBuffer, chunk], tagLengthBytes)
+        const finalAuthTagBuffer = Buffer.concat([authTagBuffer, chunk], tagLengthBytes)
         if (this._verify) {
-          this._verify.update(state.authTagBuffer)
+          this._verify.update(finalAuthTagBuffer)
         }
-        this.emit('AuthTag', state.authTagBuffer)
-        const tail = chunk.slice(left)
-        if (!currentFrame.isFinalFrame) {
-          state.buffer = Buffer.alloc(0)
-          state.currentFrame = undefined
-          state.authTagBuffer = Buffer.alloc(0)
+        /* Reset state.
+         * Ciphertext buffers and authTag buffers need to be cleared.
+         */
+        state.buffer = Buffer.alloc(0)
+        state.currentFrame = undefined
+        state.authTagBuffer = Buffer.alloc(0)
+        /* After the final frame the file format is _much_ simpler.
+         * Making sure the cascading if blocks fall to the signature can be tricky and brittle.
+         * After the final frame, just moving on to concatenate the signature is much simpler.
+         */
+        if (currentFrame.isFinalFrame) {
+          /* Overwriting the _transform function.
+           * Data flow control is not handled here.
+           */
+          this._transform = (chunk: Buffer, _enc: string, callback: Function) => {
+            if (chunk.length) {
+              state.signatureInfo = Buffer.concat([state.signatureInfo, chunk])
+            }
+
+            callback()
+          }
         }
-        return setImmediate(() => this._transform(tail, enc, callback))
-      }
-    }
 
-    if (chunk.length) {
-      state.signatureInfo = Buffer.concat([state.signatureInfo, chunk])
+        const tail = chunk.slice(left)
+        /* The decipher_stream uses the `AuthTag` event to flush the accumulated frame.
+         * This is because ciphertext should never be returned until it is verified.
+         * i.e. the auth tag checked.
+         * This can create an issue if the chucks and frame size are small.
+         * If the verify stream continues processing and sends the next auth tag,
+         * before the current auth tag has been completed.
+         * This is basically a back pressure issue.
+         * Since the frame size, and consequently the high water mark,
+         * can not be know when the stream is created,
+         * the internal stream state would need to be modified.
+         * I assert that a simple callback is a simpler way to handle this.
+         */
+        const next = () => this._transform(tail, enc, callback)
+        return this.emit('AuthTag', finalAuthTagBuffer, next)
+      }
     }
 
     callback()

modules/decrypt-node/test/decrypt.test.ts

@@ -17,45 +17,54 @@
 
 import { expect } from 'chai'
 import 'mocha'
-import {
-  NodeDecryptionMaterial, // eslint-disable-line no-unused-vars
-  NodeEncryptionMaterial, // eslint-disable-line no-unused-vars
-  KeyringNode, EncryptedDataKey,
-  KeyringTraceFlag, AlgorithmSuiteIdentifier
-} from '@aws-crypto/material-management-node'
-
-// import * as fs from 'fs'
-
-import { encrypt } from '@aws-crypto/encrypt-node'
-import { decrypt } from '../src/decrypt'
-
-describe('simple', () => {
-  it('decrypt what I encrypt', async () => {
-    class TestKeyring extends KeyringNode {
-      async _onEncrypt (material: NodeEncryptionMaterial) {
-        const unencryptedDataKey = new Uint8Array(material.suite.keyLengthBytes).fill(1)
-        const trace = { keyNamespace: 'k', keyName: 'k', flags: KeyringTraceFlag.WRAPPING_KEY_GENERATED_DATA_KEY }
-        const edk = new EncryptedDataKey({ providerId: 'k', providerInfo: 'k', encryptedDataKey: new Uint8Array(3) })
-        return material
-          .setUnencryptedDataKey(unencryptedDataKey, trace)
-          .addEncryptedDataKey(edk, KeyringTraceFlag.WRAPPING_KEY_ENCRYPTED_DATA_KEY)
-      }
-      async _onDecrypt (material: NodeDecryptionMaterial) {
-        const unencryptedDataKey = new Uint8Array(material.suite.keyLengthBytes).fill(1)
-        const trace = { keyNamespace: 'k', keyName: 'k', flags: KeyringTraceFlag.WRAPPING_KEY_DECRYPTED_DATA_KEY }
-        return material.setUnencryptedDataKey(unencryptedDataKey, trace)
-      }
-    }
-
-    const keyRing = new TestKeyring()
-    const suiteId = AlgorithmSuiteIdentifier.ALG_AES128_GCM_IV12_TAG16
-
-    const plaintext = 'asdf'
-    const { ciphertext } = await encrypt(keyRing, plaintext, { suiteId })
-
-    const { plaintext: test, messageHeader } = await decrypt(keyRing, ciphertext)
-
-    expect(messageHeader.suiteId).to.equal(suiteId)
-    expect(test.toString()).to.equal(plaintext)
+import { AlgorithmSuiteIdentifier } from '@aws-crypto/material-management-node'
+import { decrypt } from '../src/index'
+import * as fixtures from './fixtures'
+import from from 'from2'
+
+describe('decrypt', () => {
+  it('string with encoding', async () => {
+    const { plaintext: test, messageHeader } = await decrypt(
+      fixtures.decryptKeyring(),
+      fixtures.base64CiphertextAlgAes256GcmIv12Tag16HkdfSha384EcdsaP384(),
+      { encoding: 'base64' }
+    )
+
+    expect(messageHeader.suiteId).to.equal(AlgorithmSuiteIdentifier.ALG_AES256_GCM_IV12_TAG16_HKDF_SHA384_ECDSA_P384)
+    expect(messageHeader.encryptionContext).to.deep.equal(fixtures.encryptionContext())
+    expect(test.toString('base64')).to.equal(fixtures.base64Plaintext())
+  })
+
+  it('buffer', async () => {
+    const { plaintext: test, messageHeader } = await decrypt(
+      fixtures.decryptKeyring(),
+      Buffer.from(fixtures.base64CiphertextAlgAes256GcmIv12Tag16HkdfSha384EcdsaP384(), 'base64')
+    )
+
+    expect(messageHeader.suiteId).to.equal(AlgorithmSuiteIdentifier.ALG_AES256_GCM_IV12_TAG16_HKDF_SHA384_ECDSA_P384)
+    expect(messageHeader.encryptionContext).to.deep.equal(fixtures.encryptionContext())
+    expect(test.toString('base64')).to.equal(fixtures.base64Plaintext())
+  })
+
+  it('stream', async () => {
+    const ciphertext = Buffer.from(fixtures.base64CiphertextAlgAes256GcmIv12Tag16HkdfSha384EcdsaP384(), 'base64')
+    const i = ciphertext.values()
+    const ciphertextStream = from((_: number, next: Function) => {
+      /* Pushing 1 byte at time is the most annoying thing.
+       * This is done intentionally to hit _every_ boundary condition.
+       */
+      const { value, done } = i.next()
+      if (done) return next(null, null)
+      next(null, new Uint8Array([value]))
+    })
+
+    const { plaintext: test, messageHeader } = await decrypt(
+      fixtures.decryptKeyring(),
+      ciphertextStream
+    )
+
+    expect(messageHeader.suiteId).to.equal(AlgorithmSuiteIdentifier.ALG_AES256_GCM_IV12_TAG16_HKDF_SHA384_ECDSA_P384)
+    expect(messageHeader.encryptionContext).to.deep.equal(fixtures.encryptionContext())
+    expect(test.toString('base64')).to.equal(fixtures.base64Plaintext())
   })
 })

modules/decrypt-node/test/fixtures.ts

@@ -0,0 +1,53 @@
+/*
+ * Copyright 2019 Amazon.com, Inc. or its affiliates. All Rights Reserved.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License"). You may not use
+ * this file except in compliance with the License. A copy of the License is
+ * located at
+ *
+ *     http://aws.amazon.com/apache2.0/
+ *
+ * or in the "license" file accompanying this file. This file is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
+ * implied. See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+/* eslint-env mocha */
+
+import {
+  NodeDecryptionMaterial, // eslint-disable-line no-unused-vars
+  NodeEncryptionMaterial, // eslint-disable-line no-unused-vars
+  KeyringNode,
+  KeyringTraceFlag
+} from '@aws-crypto/material-management-node'
+
+export function base64CiphertextAlgAes256GcmIv12Tag16HkdfSha384EcdsaP384 () {
+  return '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'
+}
+
+export function base64Plaintext () {
+  return '3Ye0RVTIjYp9Yvi+81Dzq9h9gAUF6akM1mqTbPKMhmwgxTWuj6Wlf8UFUMG7zALPDpN77EleMS3dXUOGlr/nalmwXkBseEo+QxCJgeo6WMuB2xQHZqJT+0glM3mcl2FWwiQDZ9G84dYOW1KSDfiyISe9rTqARl0fmEnD1oB6zlP4cYg7+DDTxOOvw5RndoiOBZ+mLbZT9vHTsJkWB3HgFO06dFAtwSgjUAEaNWMjk04vIT+9SBvql6cOk+GLfUdkH33chNk22yKPF2UQ6+lvW0YqGODIfTBQXypPuuKYXJ3T583YxeiKoxuxZFpVNkg30r5cYPOYulINy+YrWQIbNFRP9Zk0CNkAJ7zsIMhQ8IXH+zG1bQmwh1RDGSAfZhmsR147Jsi6qty9Fe9O'
+}
+
+export function encryptionContext () {
+  return {
+    'aws-crypto-public-key': 'AnYtFEewZm+28KhIGpx8RhkaUaLccJpyf1nwIVQFGmypgzhH2XdSIBJ4sKiSH3ckzw==',
+    simple: 'context'
+  }
+}
+
+export function decryptKeyring () {
+  class TestKeyring extends KeyringNode {
+    async _onEncrypt () : Promise<NodeEncryptionMaterial> {
+      throw new Error('I should never see this error')
+    }
+    async _onDecrypt (material: NodeDecryptionMaterial) {
+      const unencryptedDataKey = new Uint8Array(material.suite.keyLengthBytes).fill(0)
+      const trace = { keyNamespace: 'k', keyName: 'k', flags: KeyringTraceFlag.WRAPPING_KEY_DECRYPTED_DATA_KEY }
+      return material.setUnencryptedDataKey(unencryptedDataKey, trace)
+    }
+  }
+
+  return new TestKeyring()
+}

modules/encrypt-node/package.json

@@ -24,11 +24,13 @@
   },
   "devDependencies": {
     "@types/chai": "^4.1.4",
+    "@types/from2": "^2.3.0",
     "@types/mocha": "^5.2.5",
     "@types/node": "^11.11.4",
     "@typescript-eslint/eslint-plugin": "^1.9.0",
     "@typescript-eslint/parser": "^1.9.0",
     "chai": "^4.1.2",
+    "from2": "^2.3.0",
     "mocha": "^5.2.0",
     "nyc": "^14.0.0",
     "standard": "^12.0.1",

modules/encrypt-node/src/encrypt.ts

@@ -23,7 +23,7 @@ export interface EncryptOutput {
 
 export async function encrypt (
   cmm: KeyringNode|NodeMaterialsManager,
-  plaintext: Buffer|Uint8Array|Readable|string,
+  plaintext: Buffer|Uint8Array|Readable|string|NodeJS.ReadableStream,
   op: EncryptInput = {}
 ): Promise<EncryptOutput> {
   const stream = encryptStream(cmm, op)