crypto: Improve error checking and reporting

Added checks where necessary to prevent hard crashes and gave
precedence to returning the OpenSSL error strings instead of generic
error strings.

PR-URL: https://github.com/nodejs/node/pull/3753
Reviewed-By: Fedor Indutny <fedor@indutny.com>
Reviewed-By: Shigeki Ohtsu <ohtsu@iij.ad.jp>
Reviewed-By: Michael Dawson <michael_dawson@ca.ibm.com>

src/node_crypto.cc

@@ -3394,10 +3394,14 @@ void Hmac::HmacInit(const char* hash_type, const char* key, int key_len) {
     return env()->ThrowError("Unknown message digest");
   }
   HMAC_CTX_init(&ctx_);
+  int result = 0;
   if (key_len == 0) {
-    HMAC_Init(&ctx_, "", 0, md_);
+    result = HMAC_Init(&ctx_, "", 0, md_);
   } else {
-    HMAC_Init(&ctx_, key, key_len, md_);
+    result = HMAC_Init(&ctx_, key, key_len, md_);
+  }
+  if (!result) {
+    return ThrowCryptoError(env(), ERR_get_error());
   }
   initialised_ = true;
 }
@@ -3518,7 +3522,8 @@ void Hash::New(const FunctionCallbackInfo<Value>& args) {
 
   Hash* hash = new Hash(env, args.This());
   if (!hash->HashInit(*hash_type)) {
-    return env->ThrowError("Digest method not supported");
+    return ThrowCryptoError(env, ERR_get_error(),
+                            "Digest method not supported");
   }
 }
 
@@ -3530,6 +3535,9 @@ bool Hash::HashInit(const char* hash_type) {
     return false;
   EVP_MD_CTX_init(&mdctx_);
   EVP_DigestInit_ex(&mdctx_, md_, nullptr);
+  if (0 != ERR_peek_error()) {
+    return false;
+  }
   initialised_ = true;
   return true;
 }
@@ -4211,7 +4219,8 @@ void DiffieHellman::Initialize(Environment* env, Local<Object> target) {
 
 bool DiffieHellman::Init(int primeLength, int g) {
   dh = DH_new();
-  DH_generate_parameters_ex(dh, primeLength, g, 0);
+  if (!DH_generate_parameters_ex(dh, primeLength, g, 0))
+    return false;
   bool result = VerifyContext();
   if (!result)
     return false;
@@ -4304,7 +4313,7 @@ void DiffieHellman::New(const FunctionCallbackInfo<Value>& args) {
   }
 
   if (!initialized) {
-    return env->ThrowError("Initialization failed");
+    return ThrowCryptoError(env, ERR_get_error(), "Initialization failed");
   }
 }
 
@@ -4315,11 +4324,11 @@ void DiffieHellman::GenerateKeys(const FunctionCallbackInfo<Value>& args) {
   DiffieHellman* diffieHellman = Unwrap<DiffieHellman>(args.Holder());
 
   if (!diffieHellman->initialised_) {
-    return env->ThrowError("Not initialized");
+    return ThrowCryptoError(env, ERR_get_error(), "Not initialized");
   }
 
   if (!DH_generate_key(diffieHellman->dh)) {
-    return env->ThrowError("Key generation failed");
+    return ThrowCryptoError(env, ERR_get_error(), "Key generation failed");
   }
 
   int dataSize = BN_num_bytes(diffieHellman->dh->pub_key);
@@ -4338,7 +4347,7 @@ void DiffieHellman::GetPrime(const FunctionCallbackInfo<Value>& args) {
   DiffieHellman* diffieHellman = Unwrap<DiffieHellman>(args.Holder());
 
   if (!diffieHellman->initialised_) {
-    return env->ThrowError("Not initialized");
+    return ThrowCryptoError(env, ERR_get_error(), "Not initialized");
   }
 
   int dataSize = BN_num_bytes(diffieHellman->dh->p);
@@ -4356,7 +4365,7 @@ void DiffieHellman::GetGenerator(const FunctionCallbackInfo<Value>& args) {
   DiffieHellman* diffieHellman = Unwrap<DiffieHellman>(args.Holder());
 
   if (!diffieHellman->initialised_) {
-    return env->ThrowError("Not initialized");
+    return ThrowCryptoError(env, ERR_get_error(), "Not initialized");
   }
 
   int dataSize = BN_num_bytes(diffieHellman->dh->g);
@@ -4374,7 +4383,7 @@ void DiffieHellman::GetPublicKey(const FunctionCallbackInfo<Value>& args) {
   DiffieHellman* diffieHellman = Unwrap<DiffieHellman>(args.Holder());
 
   if (!diffieHellman->initialised_) {
-    return env->ThrowError("Not initialized");
+    return ThrowCryptoError(env, ERR_get_error(), "Not initialized");
   }
 
   if (diffieHellman->dh->pub_key == nullptr) {
@@ -4397,7 +4406,7 @@ void DiffieHellman::GetPrivateKey(const FunctionCallbackInfo<Value>& args) {
   DiffieHellman* diffieHellman = Unwrap<DiffieHellman>(args.Holder());
 
   if (!diffieHellman->initialised_) {
-    return env->ThrowError("Not initialized");
+    return ThrowCryptoError(env, ERR_get_error(), "Not initialized");
   }
 
   if (diffieHellman->dh->priv_key == nullptr) {
@@ -4420,7 +4429,7 @@ void DiffieHellman::ComputeSecret(const FunctionCallbackInfo<Value>& args) {
   DiffieHellman* diffieHellman = Unwrap<DiffieHellman>(args.Holder());
 
   if (!diffieHellman->initialised_) {
-    return env->ThrowError("Not initialized");
+    return ThrowCryptoError(env, ERR_get_error(), "Not initialized");
   }
 
   ClearErrorOnReturn clear_error_on_return;
@@ -4453,7 +4462,7 @@ void DiffieHellman::ComputeSecret(const FunctionCallbackInfo<Value>& args) {
     delete[] data;
 
     if (!checked) {
-      return env->ThrowError("Invalid key");
+      return ThrowCryptoError(env, ERR_get_error(), "Invalid Key");
     } else if (checkResult) {
       if (checkResult & DH_CHECK_PUBKEY_TOO_SMALL) {
         return env->ThrowError("Supplied key is too small");
@@ -4490,7 +4499,7 @@ void DiffieHellman::SetPublicKey(const FunctionCallbackInfo<Value>& args) {
   Environment* env = diffieHellman->env();
 
   if (!diffieHellman->initialised_) {
-    return env->ThrowError("Not initialized");
+    return ThrowCryptoError(env, ERR_get_error(), "Not initialized");
   }
 
   if (args.Length() == 0) {
@@ -4509,7 +4518,7 @@ void DiffieHellman::SetPrivateKey(const FunctionCallbackInfo<Value>& args) {
   Environment* env = diffieHellman->env();
 
   if (!diffieHellman->initialised_) {
-    return env->ThrowError("Not initialized");
+    return ThrowCryptoError(env, ERR_get_error(), "Not initialized");
   }
 
   if (args.Length() == 0) {
@@ -4531,7 +4540,8 @@ void DiffieHellman::VerifyErrorGetter(Local<String> property,
   DiffieHellman* diffieHellman = Unwrap<DiffieHellman>(args.Holder());
 
   if (!diffieHellman->initialised_)
-    return diffieHellman->env()->ThrowError("Not initialized");
+    return ThrowCryptoError(diffieHellman->env(), ERR_get_error(),
+                            "Not initialized");
 
   args.GetReturnValue().Set(diffieHellman->verifyError_);
 }