Added NetworkingPrivateCrypto and its unit test.

chrome/browser/extensions/api/networking_private/networking_private_crypto.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 "chrome/browser/extensions/api/networking_private/networking_private_crypto.h"
+
+#include <cert.h>
+#include <cryptohi.h>
+#include <keyhi.h>
+#include <keythi.h>
+#include <pk11pub.h>
+#include <sechash.h>
+#include <secport.h>
+
+#include "base/base64.h"
+#include "base/memory/scoped_ptr.h"
+#include "base/strings/string_number_conversions.h"
+#include "base/strings/string_util.h"
+#include "base/strings/stringprintf.h"
+#include "crypto/nss_util.h"
+#include "crypto/rsa_private_key.h"
+#include "net/cert/pem_tokenizer.h"
+#include "net/cert/x509_certificate.h"
+
+const char kTrustedCAPublicKeyDER[] =
+    "MIIBCgKCAQEAvCKAvYD2OiEAO652XjV/"
+    "PcNkXFWUhjQvBYcozfdpjBezUKe4gvrfx0Mt1n6roG+"
+    "3E3KApEcVwSCZUM3sFGIJW6SYzdJBtjZO/"
+    "+guMjBKgahCo2ybM27KsvVTZuAnU4YahR6nOT9Kd477VGZm+1hUwF45x/"
+    "VQBgvgitTO4WpVH4sXAOZpoyfmCCVpPBKdjQUs1i6iMd60UlDWIEnecaD5rSBAEvHdJevV5rg2"
+    "9NaPf8pD3NcQW+Y/UYqFs/P/9gMtyyNPnK0Y55MFjKxSmvdM6Zl6vm5+TQrjxhypk/"
+    "o6pZFdHL1m68xg3IZ0ys/4khyYfVf6YUeeq4C35EiAKpLFGwIDAQAB";

[Ryan Sleevi, 2013/08/28 21:52:29]

Please fix this by hand. Clang format is crap here.

[mef, 2013/08/29 14:59:09]

Done. Is there actually a better way to define binary constants than base64?

+
+namespace {
+bool GetDERFromPEM(const std::string& pem_data,
+                   const std::string& pem_type,
+                   std::string* der_output) {
+  std::vector<std::string> headers;
+  headers.push_back(pem_type);
+  net::PEMTokenizer pem_tok(pem_data, headers);
+  if (!pem_tok.GetNext()) {
+    return false;
+  }
+
+  *der_output = pem_tok.data();
+  return true;
+}
+
+struct NetworkingPrivateCryptoContext {
+  NetworkingPrivateCryptoContext();
+  ~NetworkingPrivateCryptoContext();
+
+  SECKEYPublicKey* ca_public_key;
+  SECKEYPublicKey* public_key;
+  CERTCertificate* cert;

[Ryan Sleevi, 2013/08/28 21:52:29]

D'oh. I missed that all of these could be locally scoped.

see src/crypto/scoped_nss_types.h for the helper functions to be used here.

[mef, 2013/08/29 14:59:09]

Done. Nice!

+};
+
+NetworkingPrivateCryptoContext::NetworkingPrivateCryptoContext()
+    : ca_public_key(NULL), public_key(NULL), cert(NULL) {}
+
+NetworkingPrivateCryptoContext::~NetworkingPrivateCryptoContext() {
+  if (ca_public_key)
+    SECKEY_DestroyPublicKey(ca_public_key);
+  if (public_key)
+    SECKEY_DestroyPublicKey(public_key);
+  if (cert)
+    CERT_DestroyCertificate(cert);
+}
+}  // namespace
+
+NetworkingPrivateCrypto::NetworkingPrivateCrypto() {}
+
+NetworkingPrivateCrypto::~NetworkingPrivateCrypto() {}
+
+bool NetworkingPrivateCrypto::VerifyCredentials(
+    const std::string& certificate,
+    const std::string& signed_data,
+    const std::string& unsigned_data,
+    const std::string& connected_mac) {
+  crypto::EnsureNSSInit();
+  NetworkingPrivateCryptoContext ctx;
+
+  std::string cert_data;
+  if (!GetDERFromPEM(certificate, "CERTIFICATE", &cert_data)) {
+    LOG(ERROR) << "Failed to parse certificate.";
+    return false;
+  }
+  SECItem der_cert = {
+      siDERCertBuffer,
+      reinterpret_cast<unsigned char*>(const_cast<char*>(cert_data.c_str())),
+      cert_data.length()};
+  // Parse into a certificate structure.
+  ctx.cert = CERT_NewTempCertificate(
+      CERT_GetDefaultCertDB(), &der_cert, NULL, PR_FALSE, PR_TRUE);
+  if (!ctx.cert) {
+    LOG(ERROR) << "Failed to parse certificate.";
+    return false;
+  }
+  // Check that the certificate is signed by trusted CA.
+  std::string ca_key_der;
+  base::Base64Decode(kTrustedCAPublicKeyDER, &ca_key_der);
+  SECItem trusted_ca_key_der_item = {
+      siDERCertBuffer,
+      reinterpret_cast<unsigned char*>(const_cast<char*>(ca_key_der.c_str())),
+      ca_key_der.size()};
+  ctx.ca_public_key =
+      SECKEY_ImportDERPublicKey(&trusted_ca_key_der_item, CKK_RSA);
+  SECStatus verified = CERT_VerifySignedDataWithPublicKey(
+      &ctx.cert->signatureWrap, ctx.ca_public_key, NULL);
+  if (verified != SECSuccess) {
+    LOG(ERROR) << "Certificate is not issued by trusted CA.";
+    return false;
+  }
+
+  // Check that the device listed in the certificate is correct.
+  // Something like evt_e161 001a11ffacdf
+  char* common_name = CERT_GetCommonName(&ctx.cert->subject);

[Ryan Sleevi, 2013/08/28 21:52:29]

BUG: This can return NULL.

[mef, 2013/08/29 14:59:09]

Done.

+  std::string subject_name = common_name;

[Ryan Sleevi, 2013/08/28 21:52:29]

Use ctor form, not assignment form.

[mef, 2013/08/29 14:59:09]

Done.

+  PORT_Free(common_name);
+  std::string translated_mac;
+  RemoveChars(connected_mac, ":", &translated_mac);
+  if (!EndsWith(subject_name, translated_mac, false)) {
+    LOG(ERROR) << "MAC addresses don't match.";
+    return false;
+  }
+
+  // Make sure that the certificate matches the unsigned data presented.
+  // Verify that hash(unsigned_data) == public(signed_data)
+  ctx.public_key = CERT_ExtractPublicKey(ctx.cert);
+  if (!ctx.public_key) {
+    LOG(ERROR) << "Unable to extract public key from certificate.";
+    return false;
+  }
+  unsigned char rsa_hash[SHA1_LENGTH];
+  SECStatus hashed = HASH_HashBuf(HASH_AlgSHA1,
+                                  rsa_hash,
+                                  reinterpret_cast<unsigned char*>(
+                                      const_cast<char*>(unsigned_data.c_str())),
+                                  unsigned_data.size());
+  DCHECK(hashed == SECSuccess);
+  SECItem digest_item = {siBuffer, rsa_hash, sizeof(rsa_hash)};
+  SECItem signature_item = {
+      siBuffer,
+      reinterpret_cast<unsigned char*>(const_cast<char*>(signed_data.c_str())),
+      static_cast<unsigned int>(signed_data.size())};
+  verified = VFY_VerifyDigestDirect(&digest_item,

[Ryan Sleevi, 2013/08/28 21:52:29]

Sorry for the misdirect. VFY_VerifyData will let you avoid the HASH_HashBuf
part.

VFY_VerifyData(unsigned_data.c_str(), unsigned_data.size(), public_key,
&signature_item, SEC_OID_PKCS1_SHA1_WITH_RSA_ENCRYPTION, NULL);

[mef, 2013/08/29 14:59:09]

Done.

+                                    ctx.public_key,
+                                    &signature_item,
+                                    SEC_OID_PKCS1_RSA_ENCRYPTION,
+                                    SEC_OID_SHA1,
+                                    NULL);
+  if (verified != SECSuccess) {
+    LOG(ERROR) << "Signed blobs did not match.";
+    return false;
+  }
+  return true;
+}
+
+bool NetworkingPrivateCrypto::EncryptByteString(const std::string& public_key,
+                                                const std::string& data,
+                                                std::string* encrypted_output) {
+  crypto::EnsureNSSInit();
+  NetworkingPrivateCryptoContext ctx;
+
+  SECItem pub_key_der_item = {
+      siDERCertBuffer,
+      reinterpret_cast<unsigned char*>(const_cast<char*>(public_key.c_str())),
+      public_key.size()};
+  ctx.public_key = SECKEY_ImportDERPublicKey(&pub_key_der_item, CKK_RSA);
+  if (!ctx.public_key) {
+    LOG(ERROR) << "Failed to parse public key.";
+    return false;
+  }
+
+  size_t encrypted_length = SECKEY_SignatureLen(ctx.public_key);
+  scoped_ptr<unsigned char[]> rsa_output(new unsigned char[encrypted_length]);
+  SECStatus encrypted = PK11_PubEncryptPKCS1(
+      ctx.public_key,
+      rsa_output.get(),
+      reinterpret_cast<unsigned char*>(const_cast<char*>(data.data())),
+      data.length(),
+      NULL);
+  if (encrypted != SECSuccess) {
+    LOG(ERROR) << "Error during encryption.";
+    return false;
+  }
+  encrypted_output->assign(reinterpret_cast<char*>(rsa_output.get()),
+                           encrypted_length);
+  return true;
+}
+
+bool NetworkingPrivateCrypto::DecryptByteString(
+    const std::string& private_key_pem,
+    const std::string& encrypted_data,
+    std::string* decrypted_output) {
+  crypto::EnsureNSSInit();
+
+  std::string private_key_der;
+  if (!GetDERFromPEM(private_key_pem, "PRIVATE KEY", &private_key_der)) {
+    LOG(ERROR) << "Failed to parse private key PEM.";
+    return false;
+  }
+  std::vector<uint8> private_key_data(private_key_der.begin(),
+                                      private_key_der.end());
+  scoped_ptr<crypto::RSAPrivateKey> private_key(
+      crypto::RSAPrivateKey::CreateFromPrivateKeyInfo(private_key_data));
+  if (!private_key) {

[Ryan Sleevi, 2013/08/28 21:52:29]

nit: if (!private_key || !private_key->public_key())

[mef, 2013/08/29 14:59:09]

Done.

+    LOG(ERROR) << "Failed to parse private key DER.";
+    return false;
+  }
+
+  size_t encrypted_length = SECKEY_SignatureLen(private_key->public_key());
+  scoped_ptr<unsigned char[]> rsa_output(new unsigned char[encrypted_length]);
+  unsigned int output_length = 0;
+  SECStatus decrypted =
+      PK11_PrivDecryptPKCS1(private_key->key(),
+                            rsa_output.get(),
+                            &output_length,
+                            encrypted_length,
+                            reinterpret_cast<unsigned char*>(
+                                const_cast<char*>(encrypted_data.data())),
+                            encrypted_data.length());
+  if (decrypted != SECSuccess) {
+    LOG(ERROR) << "Error during encryption.";
+    return false;
+  }
+  decrypted_output->assign(reinterpret_cast<char*>(rsa_output.get()),
+                           output_length);
+  return true;
+}