crypto: better crypto error messages

Add openSSL error stack to the exception object thrown from crypto.
The new exception property is only added to the object if the error
stack has not cleared out prior to calling ThrowCryptoError.

PR-URL: https://github.com/nodejs/node/pull/15518
Refs: https://github.com/nodejs/node/issues/5444
Reviewed-By: Sam Roberts <vieuxtech@gmail.com>
Reviewed-By: Fedor Indutny <fedor.indutny@gmail.com>

4 files changed, 163 insertions, 16 deletions

diff --git a/doc/api/errors.md b/doc/api/errors.md
index ba81f2f75e..dc530c7589 100644
--- a/doc/api/errors.md
+++ b/doc/api/errors.md
@@ -192,6 +192,10 @@ circumstance of why the error occurred. `Error` objects capture a "stack trace"
 detailing the point in the code at which the `Error` was instantiated, and may
 provide a text description of the error.
 
+For crypto only, `Error` objects will include the OpenSSL error stack in a
+separate property called `opensslErrorStack` if it is available when the error
+is thrown.
+
 All errors generated by Node.js, including all System and JavaScript errors,
 will either be instances of, or inherit from, the `Error` class.
 
diff --git a/src/env.h b/src/env.h
index ef4874057a..786f87c437 100644
--- a/src/env.h
+++ b/src/env.h
@@ -224,6 +224,7 @@ class ModuleWrap;
   V(onstreamclose_string, "onstreamclose")                                    \
   V(ontrailers_string, "ontrailers")                                          \
   V(onwrite_string, "onwrite")                                                \
+  V(openssl_error_stack, "opensslErrorStack")                                 \
   V(output_string, "output")                                                  \
   V(order_string, "order")                                                    \
   V(owner_string, "owner")                                                    \
diff --git a/src/node_crypto.cc b/src/node_crypto.cc
index 0dde13f360..a1d601adf4 100644
--- a/src/node_crypto.cc
+++ b/src/node_crypto.cc
@@ -255,13 +255,65 @@ void ThrowCryptoError(Environment* env,
                       unsigned long err,  // NOLINT(runtime/int)
                       const char* default_message = nullptr) {
   HandleScope scope(env->isolate());
+  Local<String> message;
+
   if (err != 0 || default_message == nullptr) {
     char errmsg[128] = { 0 };
     ERR_error_string_n(err, errmsg, sizeof(errmsg));
-    env->ThrowError(errmsg);
+    message = String::NewFromUtf8(env->isolate(), errmsg,
+                                  v8::NewStringType::kNormal)
+                                      .ToLocalChecked();
   } else {
-    env->ThrowError(default_message);
+    message = String::NewFromUtf8(env->isolate(), default_message,
+                                  v8::NewStringType::kNormal)
+                                      .ToLocalChecked();
+  }
+
+  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;
+    }
+
+    // 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)
+        .FromJust();
   }
+
+  env->isolate()->ThrowException(exception);
 }
 
 
@@ -4276,8 +4328,6 @@ SignBase::Error Verify::VerifyFinal(const char* key_pem,
   if (!initialised_)
     return kSignNotInitialised;
 
-  ClearErrorOnReturn clear_error_on_return;
-
   EVP_PKEY* pkey = nullptr;
   BIO* bp = nullptr;
   X509* x509 = nullptr;
@@ -4366,6 +4416,8 @@ SignBase::Error Verify::VerifyFinal(const char* key_pem,
 void Verify::VerifyFinal(const FunctionCallbackInfo<Value>& args) {
   Environment* env = Environment::GetCurrent(args);
 
+  ClearErrorOnReturn clear_error_on_return;
+
   Verify* verify;
   ASSIGN_OR_RETURN_UNWRAP(&verify, args.Holder());
 
diff --git a/test/parallel/test-crypto.js b/test/parallel/test-crypto.js
index 2a704ff07c..d501991dd2 100644
--- a/test/parallel/test-crypto.js
+++ b/test/parallel/test-crypto.js
@@ -46,7 +46,14 @@ assert.throws(function() {
   const context = credentials.context;
   const notcontext = { setOptions: context.setOptions, setKey: context.setKey };
   tls.createSecureContext({ secureOptions: 1 }, notcontext);
-}, /^TypeError: Illegal invocation$/);
+}, (err) => {
+  // Throws TypeError, so there is no opensslErrorStack property.
+  if ((err instanceof Error) &&
+      /^TypeError: Illegal invocation$/.test(err) &&
+      err.opensslErrorStack === undefined) {
+    return true;
+  }
+});
 
 // PFX tests
 assert.doesNotThrow(function() {
@@ -55,15 +62,36 @@ assert.doesNotThrow(function() {
 
 assert.throws(function() {
   tls.createSecureContext({ pfx: certPfx });
-}, /^Error: mac verify failure$/);
+}, (err) => {
+  // Throws general Error, so there is no opensslErrorStack property.
+  if ((err instanceof Error) &&
+      /^Error: mac verify failure$/.test(err) &&
+      err.opensslErrorStack === undefined) {
+    return true;
+  }
+});
 
 assert.throws(function() {
   tls.createSecureContext({ pfx: certPfx, passphrase: 'test' });
-}, /^Error: mac verify failure$/);
+}, (err) => {
+  // Throws general Error, so there is no opensslErrorStack property.
+  if ((err instanceof Error) &&
+      /^Error: mac verify failure$/.test(err) &&
+      err.opensslErrorStack === undefined) {
+    return true;
+  }
+});
 
 assert.throws(function() {
   tls.createSecureContext({ pfx: 'sample', passphrase: 'test' });
-}, /^Error: not enough data$/);
+}, (err) => {
+  // Throws general Error, so there is no opensslErrorStack property.
+  if ((err instanceof Error) &&
+      /^Error: not enough data$/.test(err) &&
+      err.opensslErrorStack === undefined) {
+    return true;
+  }
+});
 
 
 // update() should only take buffers / strings
@@ -138,23 +166,62 @@ testImmutability(crypto.getCurves);
 // throw, not assert in C++ land.
 assert.throws(function() {
   crypto.createCipher('aes192', 'test').update('0', 'hex');
-}, common.hasFipsCrypto ? /not supported in FIPS mode/ : /Bad input string/);
+}, (err) => {
+  const errorMessage =
+    common.hasFipsCrypto ? /not supported in FIPS mode/ : /Bad input string/;
+  // Throws general Error, so there is no opensslErrorStack property.
+  if ((err instanceof Error) &&
+      errorMessage.test(err) &&
+      err.opensslErrorStack === undefined) {
+    return true;
+  }
+});
 
 assert.throws(function() {
   crypto.createDecipher('aes192', 'test').update('0', 'hex');
-}, common.hasFipsCrypto ? /not supported in FIPS mode/ : /Bad input string/);
+}, (err) => {
+  const errorMessage =
+    common.hasFipsCrypto ? /not supported in FIPS mode/ : /Bad input string/;
+  // Throws general Error, so there is no opensslErrorStack property.
+  if ((err instanceof Error) &&
+      errorMessage.test(err) &&
+      err.opensslErrorStack === undefined) {
+    return true;
+  }
+});
 
 assert.throws(function() {
   crypto.createHash('sha1').update('0', 'hex');
-}, /^TypeError: Bad input string$/);
+}, (err) => {
+  // Throws TypeError, so there is no opensslErrorStack property.
+  if ((err instanceof Error) &&
+      /^TypeError: Bad input string$/.test(err) &&
+      err.opensslErrorStack === undefined) {
+    return true;
+  }
+});
 
 assert.throws(function() {
   crypto.createSign('SHA1').update('0', 'hex');
-}, /^TypeError: Bad input string$/);
+}, (err) => {
+  // Throws TypeError, so there is no opensslErrorStack property.
+  if ((err instanceof Error) &&
+      /^TypeError: Bad input string$/.test(err) &&
+      err.opensslErrorStack === undefined) {
+    return true;
+  }
+});
 
 assert.throws(function() {
   crypto.createVerify('SHA1').update('0', 'hex');
-}, /^TypeError: Bad input string$/);
+}, (err) => {
+  // Throws TypeError, so there is no opensslErrorStack property.
+  if ((err instanceof Error) &&
+      /^TypeError: Bad input string$/.test(err) &&
+      err.opensslErrorStack === undefined) {
+    return true;
+  }
+});
 
 assert.throws(function() {
   const priv = [
@@ -167,7 +234,13 @@ assert.throws(function() {
     ''
   ].join('\n');
   crypto.createSign('SHA256').update('test').sign(priv);
-}, /digest too big for rsa key$/);
+}, (err) => {
+  if ((err instanceof Error) &&
+      /digest too big for rsa key$/.test(err) &&
+      err.opensslErrorStack === undefined) {
+    return true;
+  }
+});
 
 assert.throws(function() {
   // The correct header inside `test_bad_rsa_privkey.pem` should have been
@@ -183,14 +256,31 @@ assert.throws(function() {
                                             'ascii');
   // this would inject errors onto OpenSSL's error stack
   crypto.createSign('sha1').sign(sha1_privateKey);
-}, /asn1 encoding routines:ASN1_CHECK_TLEN:wrong tag/);
+}, (err) => {
+  // Throws crypto error, so there is an opensslErrorStack property.
+  // The openSSL stack should have content.
+  if ((err instanceof Error) &&
+      /asn1 encoding routines:ASN1_CHECK_TLEN:wrong tag/.test(err) &&
+      err.opensslErrorStack !== undefined &&
+      Array.isArray(err.opensslErrorStack) &&
+      err.opensslErrorStack.length > 0) {
+    return true;
+  }
+});
 
 // Make sure memory isn't released before being returned
 console.log(crypto.randomBytes(16));
 
 assert.throws(function() {
   tls.createSecureContext({ crl: 'not a CRL' });
-}, /^Error: Failed to parse CRL$/);
+}, (err) => {
+  // Throws general error, so there is no opensslErrorStack property.
+  if ((err instanceof Error) &&
+      /^Error: Failed to parse CRL$/.test(err) &&
+      err.opensslErrorStack === undefined) {
+    return true;
+  }
+});
 
 /**
  * Check if the stream function uses utf8 as a default encoding.