crypto: fix handling of root_cert_store.

SecureContext::AddRootCerts only parses the root certificates once and
keeps the result in root_cert_store, a global X509_STORE. This change
addresses the following issues:

1. SecureContext::AddCACert would add certificates to whatever
X509_STORE was being used, even if that happened to be root_cert_store.
Thus adding a CA certificate to a SecureContext would also cause it to
be included in unrelated SecureContexts.

2. AddCRL would crash if neither AddRootCerts nor AddCACert had been
called first.

3. Calling AddCACert without calling AddRootCerts first, and with an
input that didn't contain any certificates, would leak an X509_STORE.

4. AddCRL would add the CRL to whatever X509_STORE was being used. Thus,
like AddCACert, unrelated SecureContext objects could be affected.

The following, non-obvious behaviour remains: calling AddRootCerts
doesn't /add/ them, rather it sets the CA certs to be the root set and
overrides any previous CA certificates.

Points 1–3 are probably unimportant because the SecureContext is
typically configured by `createSecureContext` in `lib/_tls_common.js`.
This function either calls AddCACert or AddRootCerts and only calls
AddCRL after setting up CA certificates. Point four could still apply in
the unlikely case that someone configures a CRL without explicitly
configuring the CAs.

PR-URL: #9409
Reviewed-By: Fedor Indutny <[email protected]>
Reviewed-By: Shigeki Ohtsu <[email protected]>

Author: agl

src/node_crypto.cc

@@ -121,6 +121,7 @@ const char* const root_certs[] = {
 };
 
 X509_STORE* root_cert_store;
+std::vector<X509*>* root_certs_vector;
 
 // Just to generate static methods
 template class SSLWrap<TLSWrap>;
@@ -402,8 +403,6 @@ void SecureContext::Init(const FunctionCallbackInfo<Value>& args) {
                                  SSL_SESS_CACHE_NO_AUTO_CLEAR);
   SSL_CTX_sess_set_get_cb(sc->ctx_, SSLWrap<Connection>::GetSessionCallback);
   SSL_CTX_sess_set_new_cb(sc->ctx_, SSLWrap<Connection>::NewSessionCallback);
-
-  sc->ca_store_ = nullptr;
 }
 
 
@@ -672,8 +671,52 @@ void SecureContext::SetCert(const FunctionCallbackInfo<Value>& args) {
 }
 
 
+#if OPENSSL_VERSION_NUMBER < 0x10100000L && !defined(OPENSSL_IS_BORINGSSL)
+// This section contains OpenSSL 1.1.0 functions reimplemented for OpenSSL
+// 1.0.2 so that the following code can be written without lots of #if lines.
+
+static int X509_STORE_up_ref(X509_STORE* store) {
+  CRYPTO_add(&store->references, 1, CRYPTO_LOCK_X509_STORE);
+  return 1;
+}
+
+static int X509_up_ref(X509* cert) {
+  CRYPTO_add(&cert->references, 1, CRYPTO_LOCK_X509);
+  return 1;
+}
+#endif  // OPENSSL_VERSION_NUMBER < 0x10100000L && !OPENSSL_IS_BORINGSSL
+
+
+static X509_STORE* NewRootCertStore() {
+  if (!root_certs_vector) {
+    root_certs_vector = new std::vector<X509*>;
+
+    for (size_t i = 0; i < arraysize(root_certs); i++) {
+      BIO* bp = NodeBIO::NewFixed(root_certs[i], strlen(root_certs[i]));
+      X509 *x509 = PEM_read_bio_X509(bp, nullptr, CryptoPemCallback, nullptr);
+      BIO_free(bp);
+
+      if (x509 == nullptr) {
+        // Parse errors from the built-in roots are fatal.
+        abort();
+        return nullptr;
+      }
+
+      root_certs_vector->push_back(x509);
+    }
+  }
+
+  X509_STORE* store = X509_STORE_new();
+  for (auto& cert : *root_certs_vector) {
+    X509_up_ref(cert);
+    X509_STORE_add_cert(store, cert);
+  }
+
+  return store;
+}
+
+
 void SecureContext::AddCACert(const FunctionCallbackInfo<Value>& args) {
-  bool newCAStore = false;
   Environment* env = Environment::GetCurrent(args);
 
   SecureContext* sc;
@@ -685,26 +728,24 @@ void SecureContext::AddCACert(const FunctionCallbackInfo<Value>& args) {
     return env->ThrowTypeError("CA certificate argument is mandatory");
   }
 
-  if (!sc->ca_store_) {
-    sc->ca_store_ = X509_STORE_new();
-    newCAStore = true;
+  BIO* bio = LoadBIO(env, args[0]);
+  if (!bio) {
+    return;
   }
 
-  unsigned cert_count = 0;
-  if (BIO* bio = LoadBIO(env, args[0])) {
-    while (X509* x509 =
-        PEM_read_bio_X509(bio, nullptr, CryptoPemCallback, nullptr)) {
-      X509_STORE_add_cert(sc->ca_store_, x509);
-      SSL_CTX_add_client_CA(sc->ctx_, x509);
-      X509_free(x509);
-      cert_count += 1;
+  X509_STORE* cert_store = SSL_CTX_get_cert_store(sc->ctx_);
+  while (X509* x509 =
+             PEM_read_bio_X509(bio, nullptr, CryptoPemCallback, nullptr)) {
+    if (cert_store == root_cert_store) {
+      cert_store = NewRootCertStore();
+      SSL_CTX_set_cert_store(sc->ctx_, cert_store);
     }
-    BIO_free_all(bio);
+    X509_STORE_add_cert(cert_store, x509);
+    SSL_CTX_add_client_CA(sc->ctx_, x509);
+    X509_free(x509);
   }
 
-  if (cert_count > 0 && newCAStore) {
-    SSL_CTX_set_cert_store(sc->ctx_, sc->ca_store_);
-  }
+  BIO_free_all(bio);
 }
 
 
@@ -725,57 +766,43 @@ void SecureContext::AddCRL(const FunctionCallbackInfo<Value>& args) {
   if (!bio)
     return;
 
-  X509_CRL *x509 =
+  X509_CRL* crl =
       PEM_read_bio_X509_CRL(bio, nullptr, CryptoPemCallback, nullptr);
 
-  if (x509 == nullptr) {
+  if (crl == nullptr) {
+    return env->ThrowError("Failed to parse CRL");
     BIO_free_all(bio);
     return;
   }
 
-  X509_STORE_add_crl(sc->ca_store_, x509);
-  X509_STORE_set_flags(sc->ca_store_, X509_V_FLAG_CRL_CHECK |
-                                      X509_V_FLAG_CRL_CHECK_ALL);
+  X509_STORE* cert_store = SSL_CTX_get_cert_store(sc->ctx_);
+  if (cert_store == root_cert_store) {
+    cert_store = NewRootCertStore();
+    SSL_CTX_set_cert_store(sc->ctx_, cert_store);
+  }
+
+  X509_STORE_add_crl(cert_store, crl);
+  X509_STORE_set_flags(cert_store,
+                       X509_V_FLAG_CRL_CHECK | X509_V_FLAG_CRL_CHECK_ALL);
+
   BIO_free_all(bio);
-  X509_CRL_free(x509);
+  X509_CRL_free(crl);
 }
 
 
-
 void SecureContext::AddRootCerts(const FunctionCallbackInfo<Value>& args) {
   SecureContext* sc;
   ASSIGN_OR_RETURN_UNWRAP(&sc, args.Holder());
   ClearErrorOnReturn clear_error_on_return;
   (void) &clear_error_on_return;  // Silence compiler warning.
 
-  CHECK_EQ(sc->ca_store_, nullptr);
-
   if (!root_cert_store) {
-    root_cert_store = X509_STORE_new();
-
-    for (size_t i = 0; i < arraysize(root_certs); i++) {
-      BIO* bp = NodeBIO::NewFixed(root_certs[i], strlen(root_certs[i]));
-      if (bp == nullptr) {
-        return;
-      }
-
-      X509 *x509 = PEM_read_bio_X509(bp, nullptr, CryptoPemCallback, nullptr);
-      if (x509 == nullptr) {
-        BIO_free_all(bp);
-        return;
-      }
-
-      X509_STORE_add_cert(root_cert_store, x509);
-
-      BIO_free_all(bp);
-      X509_free(x509);
-    }
+    root_cert_store = NewRootCertStore();
   }
 
-  sc->ca_store_ = root_cert_store;
   // Increment reference count so global store is not deleted along with CTX.
-  CRYPTO_add(&root_cert_store->references, 1, CRYPTO_LOCK_X509_STORE);
-  SSL_CTX_set_cert_store(sc->ctx_, sc->ca_store_);
+  X509_STORE_up_ref(root_cert_store);
+  SSL_CTX_set_cert_store(sc->ctx_, root_cert_store);
 }
 
 
@@ -985,6 +1012,8 @@ void SecureContext::LoadPKCS12(const FunctionCallbackInfo<Value>& args) {
     sc->cert_ = nullptr;
   }
 
+  X509_STORE* cert_store = SSL_CTX_get_cert_store(sc->ctx_);
+
   if (d2i_PKCS12_bio(in, &p12) &&
       PKCS12_parse(p12, pass, &pkey, &cert, &extra_certs) &&
       SSL_CTX_use_certificate_chain(sc->ctx_,
@@ -997,11 +1026,11 @@ void SecureContext::LoadPKCS12(const FunctionCallbackInfo<Value>& args) {
     for (int i = 0; i < sk_X509_num(extra_certs); i++) {
       X509* ca = sk_X509_value(extra_certs, i);
 
-      if (!sc->ca_store_) {
-        sc->ca_store_ = X509_STORE_new();
-        SSL_CTX_set_cert_store(sc->ctx_, sc->ca_store_);
+      if (cert_store == root_cert_store) {
+        cert_store = NewRootCertStore();
+        SSL_CTX_set_cert_store(sc->ctx_, cert_store);
       }
-      X509_STORE_add_cert(sc->ca_store_, ca);
+      X509_STORE_add_cert(cert_store, ca);
       SSL_CTX_add_client_CA(sc->ctx_, ca);
     }
     ret = true;

src/node_crypto.h

@@ -76,7 +76,6 @@ class SecureContext : public BaseObject {
 
   static void Initialize(Environment* env, v8::Local<v8::Object> target);
 
-  X509_STORE* ca_store_;
   SSL_CTX* ctx_;
   X509* cert_;
   X509* issuer_;
@@ -131,7 +130,6 @@ class SecureContext : public BaseObject {
 
   SecureContext(Environment* env, v8::Local<v8::Object> wrap)
       : BaseObject(env, wrap),
-        ca_store_(nullptr),
         ctx_(nullptr),
         cert_(nullptr),
         issuer_(nullptr) {
@@ -140,20 +138,19 @@ class SecureContext : public BaseObject {
   }
 
   void FreeCTXMem() {
-    if (ctx_) {
-      env()->isolate()->AdjustAmountOfExternalAllocatedMemory(-kExternalSize);
-      SSL_CTX_free(ctx_);
-      if (cert_ != nullptr)
-        X509_free(cert_);
-      if (issuer_ != nullptr)
-        X509_free(issuer_);
-      ctx_ = nullptr;
-      ca_store_ = nullptr;
-      cert_ = nullptr;
-      issuer_ = nullptr;
-    } else {
-      CHECK_EQ(ca_store_, nullptr);
+    if (!ctx_) {
+      return;
     }
+
+    env()->isolate()->AdjustAmountOfExternalAllocatedMemory(-kExternalSize);
+    SSL_CTX_free(ctx_);
+    if (cert_ != nullptr)
+      X509_free(cert_);
+    if (issuer_ != nullptr)
+      X509_free(issuer_);
+    ctx_ = nullptr;
+    cert_ = nullptr;
+    issuer_ = nullptr;
   }
 };
 

test/parallel/test-crypto.js

@@ -141,3 +141,7 @@ assert.throws(function() {
 
 // Make sure memory isn't released before being returned
 console.log(crypto.randomBytes(16));
+
+assert.throws(function() {
+  tls.createSecureContext({ crl: 'not a CRL' });
+}, '/Failed to parse CRL/');

test/parallel/test-tls-addca.js

@@ -0,0 +1,62 @@
+'use strict';
+const common = require('../common');
+const fs = require('fs');
+
+if (!common.hasCrypto) {
+  common.skip('missing crypto');
+  return;
+}
+const tls = require('tls');
+
+function filenamePEM(n) {
+  return require('path').join(common.fixturesDir, 'keys', n + '.pem');
+}
+
+function loadPEM(n) {
+  return fs.readFileSync(filenamePEM(n));
+}
+
+const caCert = loadPEM('ca1-cert');
+const contextWithoutCert = tls.createSecureContext({});
+const contextWithCert = tls.createSecureContext({});
+// Adding a CA certificate to contextWithCert should not also add it to
+// contextWithoutCert. This is tested by trying to connect to a server that
+// depends on that CA using contextWithoutCert.
+contextWithCert.context.addCACert(caCert);
+
+const serverOptions = {
+  key: loadPEM('agent1-key'),
+  cert: loadPEM('agent1-cert'),
+};
+const server = tls.createServer(serverOptions, function() {});
+
+const clientOptions = {
+  port: undefined,
+  ca: [caCert],
+  servername: 'agent1',
+  rejectUnauthorized: true,
+};
+
+function startTest() {
+  // This client should fail to connect because it doesn't trust the CA
+  // certificate.
+  clientOptions.secureContext = contextWithoutCert;
+  clientOptions.port = server.address().port;
+  const client = tls.connect(clientOptions, common.fail);
+  client.on('error', common.mustCall(() => {
+    client.destroy();
+
+    // This time it should connect because contextWithCert includes the needed
+    // CA certificate.
+    clientOptions.secureContext = contextWithCert;
+    const client2 = tls.connect(clientOptions, common.mustCall(() => {
+      client2.destroy();
+      server.close();
+    }));
+    client2.on('error', (e) => {
+      console.log(e);
+    });
+  }));
+}
+
+server.listen(0, startTest);