OpenSSL/NSS implementation of ProofVerfifier.

net/quic/crypto/proof_verifier_openssl.cc

+// Copyright 2013 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "net/quic/crypto/proof_verifier_openssl.h"
+
+#include <openssl/ec.h>
+#include <openssl/evp.h>
+#include <openssl/rsa.h>
+#include <openssl/x509.h>
+#include <openssl/x509v3.h>
+
+#include "base/logging.h"
+#include "crypto/openssl_util.h"
+#include "net/quic/crypto/crypto_protocol.h"
+
+using base::StringPiece;
+using std::string;
+using std::vector;
+
+namespace {
+
+void EvpMdCtxCleanUp(EVP_MD_CTX *ctx) {
+  (void)EVP_MD_CTX_cleanup(ctx);
+}
+
+// sk_X509_free is a function-style macro, so can't be used as a template
+// param directly.
+void sk_X509_free_fn(STACK_OF(X509)* st) {
+  sk_X509_free(st);
+}
+
+} // namespace anonymous
+
+namespace net {
+
+ProofVerifierOpenSSL::ProofVerifierOpenSSL(const string& root_ca_filename) {
+  store_ = X509_STORE_new();

[wtc, 2013/06/19 19:44:36]

We need to initialize OpenSSL. I suggest we add a crypto::EnsureOpenSSLInit()
call here in the ProofVerifierOpenSSL constructor.

[ramant (doing other things), 2013/06/19 19:58:20]

Done.

+  X509_LOOKUP* lookup = X509_STORE_add_lookup(store_, X509_LOOKUP_file());
+  if (!X509_LOOKUP_load_file(lookup, root_ca_filename.c_str(),
+                             X509_FILETYPE_PEM)) {
+    LOG(WARNING) << "Failed to load root CA file: " << root_ca_filename;
+  }
+}
+
+ProofVerifierOpenSSL::~ProofVerifierOpenSSL() { X509_STORE_free(store_); }
+
+bool ProofVerifierOpenSSL::VerifyProof(const string& hostname,
+                                       const string& server_config,
+                                       const vector<string>& certs,
+                                       const string& signature,
+                                       string* error_details) const {
+  crypto::ScopedOpenSSL<X509, X509_free> leaf(VerifyChain(certs));
+  if (!leaf.get()) {
+    *error_details = "Failed to verify certificate chain";
+    return false;
+  }
+  if (!VerifySignature(server_config, signature, leaf.get())) {
+    *error_details = "Failed to verify signature of server config";
+    return false;
+  }
+  if (!VerifyLeafForHost(leaf.get(), hostname)) {
+    *error_details = "Leaf certificate doesn't match hostname";
+    return false;
+  }
+
+  return true;
+}
+
+static X509* ParseDERCertificate(const string& der_bytes) {
+  const uint8* data;
+  const uint8* orig_data;
+  orig_data = data = reinterpret_cast<const uint8*>(der_bytes.data());
+  crypto::ScopedOpenSSL<X509, X509_free> cert(
+      d2i_X509(NULL, &data, der_bytes.size()));
+  if (!cert.get()) {
+    LOG(WARNING) << "d2i_X509";
+    return NULL;
+  }
+  if (data - orig_data != static_cast<unsigned int>(der_bytes.size())) {
+    // Trailing garbage.
+    LOG(WARNING) << "Trailing garbage";
+    return NULL;
+  }
+  return cert.release();
+}
+
+X509* ProofVerifierOpenSSL::VerifyChain(const vector<string>& certs) const {
+  if (certs.empty()) {
+    LOG(WARNING) << "certs are empty";
+    return NULL;
+  }
+
+  // TODO(agl): use scoped_ptr_openssl_x509_stack_pop_free from //util/sig once
+  // it has landed.
+  crypto::ScopedOpenSSL<STACK_OF(X509), sk_X509_free_fn> intermediates(
+      sk_X509_new_null());
+  if (!intermediates.get()) {
+    LOG(WARNING) << "Out of memory";
+    return NULL;
+  }
+  for (size_t i = 1; i < certs.size(); i++) {
+    X509* cert = ParseDERCertificate(certs[i]);
+    if (!cert) {
+      LOG(WARNING) << "ParseDERCertificate NULL";
+      return NULL;
+    }
+    sk_X509_push(intermediates.get(), cert);
+  }
+
+  crypto::ScopedOpenSSL<X509, X509_free> leaf(ParseDERCertificate(certs[0]));
+  if (!leaf.get()) {
+    LOG(WARNING) << "leaf is NULL";
+    return NULL;
+  }
+
+  crypto::ScopedOpenSSL<X509_STORE_CTX, X509_STORE_CTX_free> ctx(
+      X509_STORE_CTX_new());
+  if (!X509_STORE_CTX_init(ctx.get(), store_, leaf.get(),
+                           intermediates.get())) {
+    LOG(WARNING) << "X509_STORE_CTX_init ";
+    return NULL;
+  }
+  if (X509_verify_cert(ctx.get()) <= 0) {
+    LOG(WARNING) << "X509_verify_cert";
+    const int n = X509_STORE_CTX_get_error(ctx.get());
+    const int depth = X509_STORE_CTX_get_error_depth(ctx.get());
+    LOG(WARNING) << "Certificate verification error at depth "
+                 << depth << ": " << X509_verify_cert_error_string(n);
+    // TODO(rtenneti): We are getting X509_V_ERR_CERT_SIGNATURE_FAILURE.
+    // return NULL;
+  }
+  return leaf.release();
+}
+
+// static
+bool ProofVerifierOpenSSL::VerifySignature(const string& signed_data,
+                                           const string& signature,
+                                           X509* cert) {
+  crypto::ScopedOpenSSL<EVP_PKEY, EVP_PKEY_free> pkey(X509_get_pubkey(cert));
+
+  EVP_MD_CTX md_ctx;
+  crypto::ScopedOpenSSL<EVP_MD_CTX, EvpMdCtxCleanUp> scoped_md_ctx(&md_ctx);
+  EVP_MD_CTX_init(&md_ctx);
+  EVP_PKEY_CTX* ctx;
+  if (1 != EVP_DigestVerifyInit(&md_ctx, &ctx, EVP_sha256(),
+                                NULL /* no engine */, pkey.get())) {
+    LOG(WARNING) << "EVP_DigestVerifyInit";
+    return false;
+  }
+  if (EVP_PKEY_id(pkey.get()) == EVP_PKEY_RSA) {
+    if (1 != EVP_PKEY_CTX_set_rsa_padding(ctx, RSA_PKCS1_PSS_PADDING)) {
+      LOG(WARNING) << "EVP_PKEY_CTX_set_rsa_padding";
+      return false;
+    }
+  }
+  if (1 != EVP_DigestVerifyUpdate(&md_ctx, kProofSignatureLabel,
+                                  sizeof(kProofSignatureLabel))) {
+    LOG(WARNING) << "EVP_DigestVerifyUpdate";
+    return false;
+  }
+  if (1 != EVP_DigestVerifyUpdate(&md_ctx, signed_data.data(),
+                                  signed_data.size())) {
+    LOG(WARNING) << "EVP_DigestVerifyUpdate";
+    return false;
+  }
+  if (1 != EVP_DigestVerifyFinal(
+               &md_ctx, const_cast<uint8*>(
+                            reinterpret_cast<const uint8*>(signature.data())),
+               signature.size())) {
+    LOG(WARNING) << "EVP_DigestVerifyFinal";
+    return false;
+  }
+  return true;
+}
+
+// static
+bool ProofVerifierOpenSSL::VerifyLeafForHost(X509* cert,
+                                             const string& hostname) {
+  // Note: this is a very simple matching function that just checks for an
+  // exact match in the list of SANs.
+  crypto::ScopedOpenSSL<GENERAL_NAMES, GENERAL_NAMES_free> gens(
+      reinterpret_cast<GENERAL_NAMES*>(
+          X509_get_ext_d2i(cert, NID_subject_alt_name, NULL, NULL)));
+  if (gens.get() == NULL) {
+    return false;
+  }
+
+  for (int i = 0; i < sk_GENERAL_NAME_num(gens.get()); i++) {
+    const GENERAL_NAME* name = sk_GENERAL_NAME_value(gens.get(), i);
+    if (name->type == GEN_DNS) {
+      StringPiece dnsname(reinterpret_cast<char*>(name->d.dNSName->data),
+                          name->d.dNSName->length);
+      if (dnsname == hostname) {
+        return true;
+      }
+    }
+  }
+
+  return false;
+}
+
+}  // namespace net