From 5c596222433166a7c0274251cca1e55f3bf9560f Mon Sep 17 00:00:00 2001
From: chux0519 <chuxdesign@hotmail.com>
Date: Sun, 4 Nov 2018 00:04:57 -0400
Subject: [PATCH] crypto: add support for chacha20-poly1305 for AEAD
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

openSSL supports AEAD_CHACHA20_POLY1305(rfc7539) since 1.1.

PR-URL: https://github.com/nodejs/node/pull/24081
Fixes: https://github.com/nodejs/node/issues/24080
Refs: https://tools.ietf.org/html/rfc7539
Reviewed-By: Ben Noordhuis <info@bnoordhuis.nl>
Reviewed-By: Sam Roberts <vieuxtech@gmail.com>
Reviewed-By: Tobias Nießen <tniessen@tnie.de>
---
 doc/api/crypto.md                          |  6 +++
 src/node_crypto.cc                         | 55 ++++++++++++----------
 test/fixtures/aead-vectors.js              | 37 +++++++++++++++
 test/parallel/test-crypto-authenticated.js |  3 +-
 4 files changed, 75 insertions(+), 26 deletions(-)

diff --git a/doc/api/crypto.md b/doc/api/crypto.md
index d12eb6d1360..81706157e62 100644
--- a/doc/api/crypto.md
+++ b/doc/api/crypto.md
@@ -1382,6 +1382,9 @@ Adversaries][] for details.
 <!-- YAML
 added: v0.1.94
 changes:
+  - version: REPLACEME
+    pr-url: https://github.com/nodejs/node/pull/24081
+    description: The cipher `chacha20-poly1305` is now supported.
   - version: v10.10.0
     pr-url: https://github.com/nodejs/node/pull/21447
     description: Ciphers in OCB mode are now supported.
@@ -1468,6 +1471,9 @@ to create the `Decipher` object.
 <!-- YAML
 added: v0.1.94
 changes:
+  - version: REPLACEME
+    pr-url: https://github.com/nodejs/node/pull/24081
+    description: The cipher `chacha20-poly1305` is now supported.
   - version: v10.10.0
     pr-url: https://github.com/nodejs/node/pull/21447
     description: Ciphers in OCB mode are now supported.
diff --git a/src/node_crypto.cc b/src/node_crypto.cc
index 6b803f685b9..8e7d7d810f4 100644
--- a/src/node_crypto.cc
+++ b/src/node_crypto.cc
@@ -2557,12 +2557,21 @@ int VerifyCallback(int preverify_ok, X509_STORE_CTX* ctx) {
   return 1;
 }
 
-static bool IsSupportedAuthenticatedMode(int mode) {
-  return mode == EVP_CIPH_CCM_MODE ||
+static bool IsSupportedAuthenticatedMode(const EVP_CIPHER* cipher) {
+  const int mode = EVP_CIPHER_mode(cipher);
+  // Check `chacha20-poly1305` separately, it is also an AEAD cipher,
+  // but its mode is 0 which doesn't indicate
+  return EVP_CIPHER_nid(cipher) == NID_chacha20_poly1305 ||
+         mode == EVP_CIPH_CCM_MODE ||
          mode == EVP_CIPH_GCM_MODE ||
          IS_OCB_MODE(mode);
 }
 
+static bool IsSupportedAuthenticatedMode(const EVP_CIPHER_CTX* ctx) {
+  const EVP_CIPHER* cipher = EVP_CIPHER_CTX_cipher(ctx);
+  return IsSupportedAuthenticatedMode(cipher);
+}
+
 void CipherBase::Initialize(Environment* env, Local<Object> target) {
   Local<FunctionTemplate> t = env->NewFunctionTemplate(New);
 
@@ -2610,7 +2619,7 @@ void CipherBase::CommonInit(const char* cipher_type,
                             "Failed to initialize cipher");
   }
 
-  if (IsSupportedAuthenticatedMode(mode)) {
+  if (IsSupportedAuthenticatedMode(cipher)) {
     CHECK_GE(iv_len, 0);
     if (!InitAuthenticated(cipher_type, iv_len, auth_tag_len))
       return;
@@ -2712,8 +2721,7 @@ void CipherBase::InitIv(const char* cipher_type,
   }
 
   const int expected_iv_len = EVP_CIPHER_iv_length(cipher);
-  const int mode = EVP_CIPHER_mode(cipher);
-  const bool is_authenticated_mode = IsSupportedAuthenticatedMode(mode);
+  const bool is_authenticated_mode = IsSupportedAuthenticatedMode(cipher);
   const bool has_iv = iv_len >= 0;
 
   // Throw if no IV was passed and the cipher requires an IV
@@ -2785,7 +2793,20 @@ bool CipherBase::InitAuthenticated(const char* cipher_type, int iv_len,
   }
 
   const int mode = EVP_CIPHER_CTX_mode(ctx_.get());
-  if (mode == EVP_CIPH_CCM_MODE || IS_OCB_MODE(mode)) {
+  if (mode == EVP_CIPH_GCM_MODE) {
+    if (auth_tag_len != kNoAuthTagLength) {
+      if (!IsValidGCMTagLength(auth_tag_len)) {
+        char msg[50];
+        snprintf(msg, sizeof(msg),
+            "Invalid authentication tag length: %u", auth_tag_len);
+        env()->ThrowError(msg);
+        return false;
+      }
+
+      // Remember the given authentication tag length for later.
+      auth_tag_len_ = auth_tag_len;
+    }
+  } else {
     if (auth_tag_len == kNoAuthTagLength) {
       char msg[128];
       snprintf(msg, sizeof(msg), "authTagLength required for %s", cipher_type);
@@ -2818,21 +2839,6 @@ bool CipherBase::InitAuthenticated(const char* cipher_type, int iv_len,
       if (iv_len == 12) max_message_size_ = 16777215;
       if (iv_len == 13) max_message_size_ = 65535;
     }
-  } else {
-    CHECK_EQ(mode, EVP_CIPH_GCM_MODE);
-
-    if (auth_tag_len != kNoAuthTagLength) {
-      if (!IsValidGCMTagLength(auth_tag_len)) {
-        char msg[50];
-        snprintf(msg, sizeof(msg),
-            "Invalid authentication tag length: %u", auth_tag_len);
-        env()->ThrowError(msg);
-        return false;
-      }
-
-      // Remember the given authentication tag length for later.
-      auth_tag_len_ = auth_tag_len;
-    }
   }
 
   return true;
@@ -2855,8 +2861,7 @@ bool CipherBase::CheckCCMMessageLength(int message_len) {
 bool CipherBase::IsAuthenticatedMode() const {
   // Check if this cipher operates in an AEAD mode that we support.
   CHECK(ctx_);
-  const int mode = EVP_CIPHER_CTX_mode(ctx_.get());
-  return IsSupportedAuthenticatedMode(mode);
+  return IsSupportedAuthenticatedMode(ctx_.get());
 }
 
 
@@ -2901,7 +2906,7 @@ void CipherBase::SetAuthTag(const FunctionCallbackInfo<Value>& args) {
   } else {
     // At this point, the tag length is already known and must match the
     // length of the given authentication tag.
-    CHECK(mode == EVP_CIPH_CCM_MODE || IS_OCB_MODE(mode));
+    CHECK(IsSupportedAuthenticatedMode(cipher->ctx_.get()));
     CHECK_NE(cipher->auth_tag_len_, kNoAuthTagLength);
     is_valid = cipher->auth_tag_len_ == tag_len;
   }
@@ -3108,7 +3113,7 @@ bool CipherBase::Final(unsigned char** out, int* out_len) {
   *out = Malloc<unsigned char>(
       static_cast<size_t>(EVP_CIPHER_CTX_block_size(ctx_.get())));
 
-  if (kind_ == kDecipher && IsSupportedAuthenticatedMode(mode)) {
+  if (kind_ == kDecipher && IsSupportedAuthenticatedMode(ctx_.get())) {
     MaybePassAuthTagToOpenSSL();
   }
 
diff --git a/test/fixtures/aead-vectors.js b/test/fixtures/aead-vectors.js
index 14933bb0cc6..6b1d169b2a7 100644
--- a/test/fixtures/aead-vectors.js
+++ b/test/fixtures/aead-vectors.js
@@ -662,5 +662,42 @@ module.exports = [
         '481529c76b6a',
     tag: 'd0c515f4d1cdd4fdac4f02ab',
     tampered: true
+  },
+
+  // Test case from rfc7539 section 2.8.2
+  { algo: 'chacha20-poly1305',
+    key: '808182838485868788898a8b8c8d8e8f909192939495969798999a9b9c9d9e9f',
+    iv: '070000004041424344454647',
+    plain: '4c616469657320616e642047656e746c656d656e206f662074686520636c6173' +
+           '73206f66202739393a204966204920636f756c64206f6666657220796f75206f' +
+           '6e6c79206f6e652074697020666f7220746865206675747572652c2073756e73' +
+           '637265656e20776f756c642062652069742e',
+    plainIsHex: true,
+    aad: '50515253c0c1c2c3c4c5c6c7',
+    ct: 'd31a8d34648e60db7b86afbc53ef7ec2a4aded51296e08fea9e2b5' +
+        'a736ee62d63dbea45e8ca9671282fafb69da92728b1a71de0a9e06' +
+        '0b2905d6a5b67ecd3b3692ddbd7f2d778b8c9803aee328091b58fa' +
+        'b324e4fad675945585808b4831d7bc3ff4def08e4b7a9de576d265' +
+        '86cec64b6116',
+    tag: '1ae10b594f09e26a7e902ecbd0600691',
+    tampered: false
+  },
+
+  { algo: 'chacha20-poly1305',
+    key: '808182838485868788898a8b8c8d8e8f909192939495969798999a9b9c9d9e9f',
+    iv: '070000004041424344454647',
+    plain: '4c616469657320616e642047656e746c656d656e206f662074686520636c6173' +
+           '73206f66202739393a204966204920636f756c64206f6666657220796f75206f' +
+           '6e6c79206f6e652074697020666f7220746865206675747572652c2073756e73' +
+           '637265656e20776f756c642062652069742e',
+    plainIsHex: true,
+    aad: '50515253c0c1c2c3c4c5c6c7',
+    ct: 'd31a8d34648e60db7b86afbc53ef7ec2a4aded51296e08fea9e2b5' +
+        'a736ee62d63dbea45e8ca9671282fafb69da92728b1a71de0a9e06' +
+        '0b2905d6a5b67ecd3b3692ddbd7f2d778b8c9803aee328091b58fa' +
+        'b324e4fad675945585808b4831d7bc3ff4def08e4b7a9de576d265' +
+        '86cec64b6116',
+    tag: '1ae10b594f09e26a7e902ecbd0600692',
+    tampered: true
   }
 ];
diff --git a/test/parallel/test-crypto-authenticated.js b/test/parallel/test-crypto-authenticated.js
index ec5c05cb120..01ce1d99968 100644
--- a/test/parallel/test-crypto-authenticated.js
+++ b/test/parallel/test-crypto-authenticated.js
@@ -94,9 +94,10 @@ for (const test of TEST_CASES) {
 
   const isCCM = /^aes-(128|192|256)-ccm$/.test(test.algo);
   const isOCB = /^aes-(128|192|256)-ocb$/.test(test.algo);
+  const isChacha20Poly1305 = test.algo === 'chacha20-poly1305';
 
   let options;
-  if (isCCM || isOCB)
+  if (isCCM || isOCB || isChacha20Poly1305)
     options = { authTagLength: test.tag.length / 2 };
 
   const inputEncoding = test.plainIsHex ? 'hex' : 'ascii';