From f5e7010eb97732ed20b18bcae6acc2e9d0616d5d Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Tobias=20Nie=C3=9Fen?= <tniessen@tnie.de>
Date: Mon, 23 Apr 2018 16:14:22 +0200
Subject: [PATCH] crypto: use kNoAuthTagLength in InitAuthenticated

Backport-PR-URL: https://github.com/nodejs/node/pull/20706
PR-URL: https://github.com/nodejs/node/pull/20225
Refs: https://github.com/nodejs/node/pull/20039
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Daniel Bevenius <daniel.bevenius@gmail.com>
Reviewed-By: Ben Noordhuis <info@bnoordhuis.nl>
---
 src/node_crypto.cc | 30 +++++++++++++++++++++---------
 src/node_crypto.h  |  7 ++++---
 2 files changed, 25 insertions(+), 12 deletions(-)

diff --git a/src/node_crypto.cc b/src/node_crypto.cc
index 07f221c02a5b84..fc6368536707f4 100644
--- a/src/node_crypto.cc
+++ b/src/node_crypto.cc
@@ -2622,7 +2622,7 @@ void CipherBase::New(const FunctionCallbackInfo<Value>& args) {
 void CipherBase::Init(const char* cipher_type,
                       const char* key_buf,
                       int key_buf_len,
-                      int auth_tag_len) {
+                      unsigned int auth_tag_len) {
   HandleScope scope(env()->isolate());
 
 #ifdef NODE_FIPS_MODE
@@ -2693,10 +2693,16 @@ void CipherBase::Init(const FunctionCallbackInfo<Value>& args) {
   const node::Utf8Value cipher_type(args.GetIsolate(), args[0]);
   const char* key_buf = Buffer::Data(args[1]);
   ssize_t key_buf_len = Buffer::Length(args[1]);
-  CHECK(args[2]->IsInt32());
+
   // Don't assign to cipher->auth_tag_len_ directly; the value might not
   // represent a valid length at this point.
-  int auth_tag_len = args[2].As<v8::Int32>()->Value();
+  unsigned int auth_tag_len;
+  if (args[2]->IsUint32()) {
+    auth_tag_len = args[2].As<v8::Uint32>()->Value();
+  } else {
+    CHECK(args[2]->IsInt32() && args[2].As<v8::Int32>()->Value() == -1);
+    auth_tag_len = kNoAuthTagLength;
+  }
 
   cipher->Init(*cipher_type, key_buf, key_buf_len, auth_tag_len);
 }
@@ -2707,7 +2713,7 @@ void CipherBase::InitIv(const char* cipher_type,
                         int key_len,
                         const char* iv,
                         int iv_len,
-                        int auth_tag_len) {
+                        unsigned int auth_tag_len) {
   HandleScope scope(env()->isolate());
 
   const EVP_CIPHER* const cipher = EVP_get_cipherbyname(cipher_type);
@@ -2781,10 +2787,16 @@ void CipherBase::InitIv(const FunctionCallbackInfo<Value>& args) {
     iv_buf = Buffer::Data(args[2]);
     iv_len = Buffer::Length(args[2]);
   }
-  CHECK(args[3]->IsInt32());
+
   // Don't assign to cipher->auth_tag_len_ directly; the value might not
   // represent a valid length at this point.
-  int auth_tag_len = args[3].As<v8::Int32>()->Value();
+  unsigned int auth_tag_len;
+  if (args[3]->IsUint32()) {
+    auth_tag_len = args[3].As<v8::Uint32>()->Value();
+  } else {
+    CHECK(args[3]->IsInt32() && args[3].As<v8::Int32>()->Value() == -1);
+    auth_tag_len = kNoAuthTagLength;
+  }
 
   cipher->InitIv(*cipher_type, key_buf, key_len, iv_buf, iv_len, auth_tag_len);
 }
@@ -2795,7 +2807,7 @@ static bool IsValidGCMTagLength(unsigned int tag_len) {
 }
 
 bool CipherBase::InitAuthenticated(const char *cipher_type, int iv_len,
-                                   int auth_tag_len) {
+                                   unsigned int auth_tag_len) {
   CHECK(IsAuthenticatedMode());
 
   if (!EVP_CIPHER_CTX_ctrl(ctx_, EVP_CTRL_AEAD_SET_IVLEN, iv_len, nullptr)) {
@@ -2805,7 +2817,7 @@ bool CipherBase::InitAuthenticated(const char *cipher_type, int iv_len,
 
   const int mode = EVP_CIPHER_CTX_mode(ctx_);
   if (mode == EVP_CIPH_CCM_MODE) {
-    if (auth_tag_len < 0) {
+    if (auth_tag_len == kNoAuthTagLength) {
       char msg[128];
       snprintf(msg, sizeof(msg), "authTagLength required for %s", cipher_type);
       env()->ThrowError(msg);
@@ -2840,7 +2852,7 @@ bool CipherBase::InitAuthenticated(const char *cipher_type, int iv_len,
   } else {
     CHECK_EQ(mode, EVP_CIPH_GCM_MODE);
 
-    if (auth_tag_len >= 0) {
+    if (auth_tag_len != kNoAuthTagLength) {
       if (!IsValidGCMTagLength(auth_tag_len)) {
         char msg[50];
         snprintf(msg, sizeof(msg),
diff --git a/src/node_crypto.h b/src/node_crypto.h
index 285a00a7a6a735..6f34eae3591252 100644
--- a/src/node_crypto.h
+++ b/src/node_crypto.h
@@ -365,14 +365,15 @@ class CipherBase : public BaseObject {
   void Init(const char* cipher_type,
             const char* key_buf,
             int key_buf_len,
-            int auth_tag_len);
+            unsigned int auth_tag_len);
   void InitIv(const char* cipher_type,
               const char* key,
               int key_len,
               const char* iv,
               int iv_len,
-              int auth_tag_len);
-  bool InitAuthenticated(const char *cipher_type, int iv_len, int auth_tag_len);
+              unsigned int auth_tag_len);
+  bool InitAuthenticated(const char *cipher_type, int iv_len,
+                         unsigned int auth_tag_len);
   bool CheckCCMMessageLength(int message_len);
   UpdateResult Update(const char* data, int len, unsigned char** out,
                       int* out_len);