crypto: don't reach into OpenSSL internals for ThrowCryptoError

There is a perfectly serviceable ERR_get_error function which avoids having to sniff through the OpenSSL ring buffer like that. It does return the errors in the opposite order, but that's easily fixed with std::reverse. Note this behavior is slightly different in that an ERR_get_error loop will ultimately clear the error queue, but this is desireable. Leaving the error queue uncleared means errors in subsequent operations may get mixed up and cause issues.

Author: davidben

src/node_crypto.cc

@@ -42,11 +42,13 @@
 // StartComAndWoSignData.inc
 #include "StartComAndWoSignData.inc"
 
+#include <algorithm>
 #include <errno.h>
 #include <limits.h> // INT_MAX
 #include <math.h>
 #include <stdlib.h>
 #include <string.h>
+#include <vector>
 
 #define THROW_AND_RETURN_IF_NOT_BUFFER(val, prefix) \
  do { \
@@ -262,44 +264,33 @@ void ThrowCryptoError(Environment* env,
  Local<Value> exception_v = Exception::Error(message);
  CHECK(!exception_v.IsEmpty());
  Local<Object> exception = exception_v.As<Object>();
- ERR_STATE* es = ERR_get_state();
-
- if (es->bottom != es->top) {
- Local<Array> error_stack = Array::New(env->isolate());
- int top = es->top;
-
- // Build the error_stack array to be added to opensslErrorStack property.
- for (unsigned int i = 0; es->bottom != es->top;) {
- unsigned long err_buf = es->err_buffer[es->top]; // NOLINT(runtime/int)
- // Only add error string if there is valid err_buffer.
- if (err_buf) {
- char tmp_str[256];
- ERR_error_string_n(err_buf, tmp_str, sizeof(tmp_str));
- error_stack->Set(env->context(), i,
- String::NewFromUtf8(env->isolate(), tmp_str,
- v8::NewStringType::kNormal)
- .ToLocalChecked()).FromJust();
- // Only increment if we added to error_stack.
- i++;
- }
 
-  // Since the ERR_STATE is a ring buffer, we need to use modular
-  // arithmetic to loop back around in the case where bottom is after top.
-  // Using ERR_NUM_ERRORS macro defined in openssl.
-  es->top = (((es->top - 1) % ERR_NUM_ERRORS) + ERR_NUM_ERRORS) %
-  ERR_NUM_ERRORS;
+ std::vector<Local<String>> errors;
+ for (;;) {
+ unsigned long err = ERR_get_error(); // NOLINT(runtime/int)
+ if (err == 0) {
+ break;
  }
-
- // Restore top.
- es->top = top;
-
- // Add the opensslErrorStack property to the exception object.
- // The new property will look like the following:
- // opensslErrorStack: [
- // 'error:0906700D:PEM routines:PEM_ASN1_read_bio:ASN1 lib',
- // 'error:0D07803A:asn1 encoding routines:ASN1_ITEM_EX_D2I:nested asn1 err'
- // ]
- exception->Set(env->context(), env->openssl_error_stack(), error_stack)
+ char tmp_str[256];
+ ERR_error_string_n(err, tmp_str, sizeof(tmp_str));
+ errors.push_back(String::NewFromUtf8(env->isolate(), tmp_str,
+ v8::NewStringType::kNormal)
+ .ToLocalChecked());
+ }
+
+ // ERR_get_error returns errors in order of most specific to least
+ // specific. We wish to have the reverse ordering:
+ // opensslErrorStack: [
+ // 'error:0906700D:PEM routines:PEM_ASN1_read_bio:ASN1 lib',
+ // 'error:0D07803A:asn1 encoding routines:ASN1_ITEM_EX_D2I:nested asn1 err'
+ // ]
+ if (!errors.empty()) {
+ std::reverse(errors.begin(), errors.end());
+ Local<Array> errors_array = Array::New(env->isolate(), errors.size());
+ for (size_t i = 0; i < errors.size(); i++) {
+ errors_array->Set(env->context(), i, errors[i]).FromJust();
+ }
+ exception->Set(env->context(), env->openssl_error_stack(), errors_array)
  .FromJust();
  }