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android / platform / external / chromium_org / 08fd22434aed8d58d4e04bbbc0df2a942440bcc5 / . / content / child / webcrypto / platform_crypto_nss.cc
blob: c5c18afc3d47011e7106c085f9ca7eb2cfa4bc78 [file] [log] [blame]
// Copyright 2014 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 "content/child/webcrypto/platform_crypto.h"
#include <cryptohi.h>
#include <pk11pub.h>
#include <secerr.h>
#include <sechash.h>
#include <vector>
#include "base/lazy_instance.h"
#include "base/logging.h"
#include "base/memory/scoped_ptr.h"
#include "content/child/webcrypto/crypto_data.h"
#include "content/child/webcrypto/status.h"
#include "content/child/webcrypto/webcrypto_util.h"
#include "crypto/nss_util.h"
#include "crypto/scoped_nss_types.h"
#include "third_party/WebKit/public/platform/WebCryptoAlgorithm.h"
#include "third_party/WebKit/public/platform/WebCryptoAlgorithmParams.h"
#include "third_party/WebKit/public/platform/WebCryptoKeyAlgorithm.h"
#if defined(USE_NSS)
#include <dlfcn.h>
#include <secoid.h>
#endif
// At the time of this writing:
// * Windows and Mac builds ship with their own copy of NSS (3.15+)
// * Linux builds use the system's libnss, which is 3.14 on Debian (but 3.15+
// on other distros).
//
// Since NSS provides AES-GCM support starting in version 3.15, it may be
// unavailable for Linux Chrome users.
//
// * !defined(CKM_AES_GCM)
//
// This means that at build time, the NSS header pkcs11t.h is older than
// 3.15. However at runtime support may be present.
//
// * !defined(USE_NSS)
//
// This means that Chrome is being built with an embedded copy of NSS,
// which can be assumed to be >= 3.15. On the other hand if USE_NSS is
// defined, it also implies running on Linux.
//
// TODO(eroman): Simplify this once 3.15+ is required by Linux builds.
#if !defined(CKM_AES_GCM)
#define CKM_AES_GCM 0x00001087
struct CK_GCM_PARAMS {
CK_BYTE_PTR pIv;
CK_ULONG ulIvLen;
CK_BYTE_PTR pAAD;
CK_ULONG ulAADLen;
CK_ULONG ulTagBits;
};
#endif // !defined(CKM_AES_GCM)
namespace {
// Signature for PK11_Encrypt and PK11_Decrypt.
typedef SECStatus (*PK11_EncryptDecryptFunction)(PK11SymKey*,
CK_MECHANISM_TYPE,
SECItem*,
unsigned char*,
unsigned int*,
unsigned int,
const unsigned char*,
unsigned int);
// Signature for PK11_PubEncrypt
typedef SECStatus (*PK11_PubEncryptFunction)(SECKEYPublicKey*,
CK_MECHANISM_TYPE,
SECItem*,
unsigned char*,
unsigned int*,
unsigned int,
const unsigned char*,
unsigned int,
void*);
// Signature for PK11_PrivDecrypt
typedef SECStatus (*PK11_PrivDecryptFunction)(SECKEYPrivateKey*,
CK_MECHANISM_TYPE,
SECItem*,
unsigned char*,
unsigned int*,
unsigned int,
const unsigned char*,
unsigned int);
// Singleton to abstract away dynamically loading libnss3.so
class NssRuntimeSupport {
public:
bool IsAesGcmSupported() const {
return pk11_encrypt_func_ && pk11_decrypt_func_;
}
bool IsRsaOaepSupported() const {
return pk11_pub_encrypt_func_ && pk11_priv_decrypt_func_ &&
internal_slot_does_oaep_;
}
// Returns NULL if unsupported.
PK11_EncryptDecryptFunction pk11_encrypt_func() const {
return pk11_encrypt_func_;
}
// Returns NULL if unsupported.
PK11_EncryptDecryptFunction pk11_decrypt_func() const {
return pk11_decrypt_func_;
}
// Returns NULL if unsupported.
PK11_PubEncryptFunction pk11_pub_encrypt_func() const {
return pk11_pub_encrypt_func_;
}
// Returns NULL if unsupported.
PK11_PrivDecryptFunction pk11_priv_decrypt_func() const {
return pk11_priv_decrypt_func_;
}
private:
friend struct base::DefaultLazyInstanceTraits<NssRuntimeSupport>;
NssRuntimeSupport() : internal_slot_does_oaep_(false) {
#if !defined(USE_NSS)
// Using a bundled version of NSS that is guaranteed to have this symbol.
pk11_encrypt_func_ = PK11_Encrypt;
pk11_decrypt_func_ = PK11_Decrypt;
pk11_pub_encrypt_func_ = PK11_PubEncrypt;
pk11_priv_decrypt_func_ = PK11_PrivDecrypt;
internal_slot_does_oaep_ = true;
#else
// Using system NSS libraries and PCKS #11 modules, which may not have the
// necessary function (PK11_Encrypt) or mechanism support (CKM_AES_GCM).
// If PK11_Encrypt() was successfully resolved, then NSS will support
// AES-GCM directly. This was introduced in NSS 3.15.
pk11_encrypt_func_ = reinterpret_cast<PK11_EncryptDecryptFunction>(
dlsym(RTLD_DEFAULT, "PK11_Encrypt"));
pk11_decrypt_func_ = reinterpret_cast<PK11_EncryptDecryptFunction>(
dlsym(RTLD_DEFAULT, "PK11_Decrypt"));
// Even though NSS's pk11wrap layer may support
// PK11_PubEncrypt/PK11_PubDecrypt (introduced in NSS 3.16.2), it may have
// loaded a softoken that does not include OAEP support.
pk11_pub_encrypt_func_ = reinterpret_cast<PK11_PubEncryptFunction>(
dlsym(RTLD_DEFAULT, "PK11_PubEncrypt"));
pk11_priv_decrypt_func_ = reinterpret_cast<PK11_PrivDecryptFunction>(
dlsym(RTLD_DEFAULT, "PK11_PrivDecrypt"));
if (pk11_priv_decrypt_func_ && pk11_pub_encrypt_func_) {
crypto::ScopedPK11Slot slot(PK11_GetInternalKeySlot());
internal_slot_does_oaep_ =
!!PK11_DoesMechanism(slot.get(), CKM_RSA_PKCS_OAEP);
}
#endif
}
PK11_EncryptDecryptFunction pk11_encrypt_func_;
PK11_EncryptDecryptFunction pk11_decrypt_func_;
PK11_PubEncryptFunction pk11_pub_encrypt_func_;
PK11_PrivDecryptFunction pk11_priv_decrypt_func_;
bool internal_slot_does_oaep_;
};
base::LazyInstance<NssRuntimeSupport>::Leaky g_nss_runtime_support =
LAZY_INSTANCE_INITIALIZER;
} // namespace
namespace content {
namespace webcrypto {
namespace platform {
// Each key maintains a copy of its serialized form
// in either 'raw', 'pkcs8', or 'spki' format. This is to allow
// structured cloning of keys synchronously from the target Blink
// thread without having to lock access to the key.
//
// TODO(eroman): Take advantage of this for implementing exportKey(): no need
// to call into NSS if the serialized form already exists.
// http://crubg.com/366836
class SymKey : public Key {
public:
static Status Create(crypto::ScopedPK11SymKey key, scoped_ptr<SymKey>* out) {
out->reset(new SymKey(key.Pass()));
return ExportKeyRaw(out->get(), &(*out)->serialized_key_);
}
PK11SymKey* key() { return key_.get(); }
virtual SymKey* AsSymKey() OVERRIDE { return this; }
virtual PublicKey* AsPublicKey() OVERRIDE { return NULL; }
virtual PrivateKey* AsPrivateKey() OVERRIDE { return NULL; }
virtual bool ThreadSafeSerializeForClone(
blink::WebVector<uint8>* key_data) OVERRIDE {
key_data->assign(Uint8VectorStart(serialized_key_), serialized_key_.size());
return true;
}
private:
explicit SymKey(crypto::ScopedPK11SymKey key) : key_(key.Pass()) {}
crypto::ScopedPK11SymKey key_;
std::vector<uint8> serialized_key_;
DISALLOW_COPY_AND_ASSIGN(SymKey);
};
class PublicKey : public Key {
public:
static Status Create(crypto::ScopedSECKEYPublicKey key,
scoped_ptr<PublicKey>* out) {
out->reset(new PublicKey(key.Pass()));
return ExportKeySpki(out->get(), &(*out)->serialized_key_);
}
SECKEYPublicKey* key() { return key_.get(); }
virtual SymKey* AsSymKey() OVERRIDE { return NULL; }
virtual PublicKey* AsPublicKey() OVERRIDE { return this; }
virtual PrivateKey* AsPrivateKey() OVERRIDE { return NULL; }
virtual bool ThreadSafeSerializeForClone(
blink::WebVector<uint8>* key_data) OVERRIDE {
key_data->assign(Uint8VectorStart(serialized_key_), serialized_key_.size());
return true;
}
private:
explicit PublicKey(crypto::ScopedSECKEYPublicKey key) : key_(key.Pass()) {}
crypto::ScopedSECKEYPublicKey key_;
std::vector<uint8> serialized_key_;
DISALLOW_COPY_AND_ASSIGN(PublicKey);
};
class PrivateKey : public Key {
public:
static Status Create(crypto::ScopedSECKEYPrivateKey key,
const blink::WebCryptoKeyAlgorithm& algorithm,
scoped_ptr<PrivateKey>* out) {
out->reset(new PrivateKey(key.Pass()));
return ExportKeyPkcs8(out->get(), algorithm, &(*out)->serialized_key_);
}
SECKEYPrivateKey* key() { return key_.get(); }
virtual SymKey* AsSymKey() OVERRIDE { return NULL; }
virtual PublicKey* AsPublicKey() OVERRIDE { return NULL; }
virtual PrivateKey* AsPrivateKey() OVERRIDE { return this; }
virtual bool ThreadSafeSerializeForClone(
blink::WebVector<uint8>* key_data) OVERRIDE {
key_data->assign(Uint8VectorStart(serialized_key_), serialized_key_.size());
return true;
}
private:
explicit PrivateKey(crypto::ScopedSECKEYPrivateKey key) : key_(key.Pass()) {}
crypto::ScopedSECKEYPrivateKey key_;
std::vector<uint8> serialized_key_;
DISALLOW_COPY_AND_ASSIGN(PrivateKey);
};
namespace {
Status NssSupportsAesGcm() {
if (g_nss_runtime_support.Get().IsAesGcmSupported())
return Status::Success();
return Status::ErrorUnsupported(
"NSS version doesn't support AES-GCM. Try using version 3.15 or later");
}
Status NssSupportsRsaOaep() {
if (g_nss_runtime_support.Get().IsRsaOaepSupported())
return Status::Success();
return Status::ErrorUnsupported(
"NSS version doesn't support RSA-OAEP. Try using version 3.16.2 or "
"later");
}
#if defined(USE_NSS) && !defined(OS_CHROMEOS)
Status ErrorRsaKeyImportNotSupported() {
return Status::ErrorUnsupported(
"NSS version must be at least 3.16.2 for RSA key import. See "
"http://crbug.com/380424");
}
Status NssSupportsKeyImport(blink::WebCryptoAlgorithmId algorithm) {
// Prior to NSS 3.16.2 RSA key parameters were not validated. This is
// a security problem for RSA private key import from JWK which uses a
// CKA_ID based on the public modulus to retrieve the private key.
if (!IsAlgorithmRsa(algorithm))
return Status::Success();
if (!NSS_VersionCheck("3.16.2"))
return ErrorRsaKeyImportNotSupported();
// Also ensure that the version of Softoken is 3.16.2 or later.
crypto::ScopedPK11Slot slot(PK11_GetInternalSlot());
CK_SLOT_INFO info = {};
if (PK11_GetSlotInfo(slot.get(), &info) != SECSuccess)
return ErrorRsaKeyImportNotSupported();
// CK_SLOT_INFO.hardwareVersion contains the major.minor
// version info for Softoken in the corresponding .major/.minor
// fields, and .firmwareVersion contains the patch.build
// version info (in the .major/.minor fields)
if ((info.hardwareVersion.major > 3) ||
(info.hardwareVersion.major == 3 &&
(info.hardwareVersion.minor > 16 ||
(info.hardwareVersion.minor == 16 &&
info.firmwareVersion.major >= 2)))) {
return Status::Success();
}
return ErrorRsaKeyImportNotSupported();
}
#else
Status NssSupportsKeyImport(blink::WebCryptoAlgorithmId) {
return Status::Success();
}
#endif
// Creates a SECItem for the data in |buffer|. This does NOT make a copy, so
// |buffer| should outlive the SECItem.
SECItem MakeSECItemForBuffer(const CryptoData& buffer) {
SECItem item = {
siBuffer,
// NSS requires non-const data even though it is just for input.
const_cast<unsigned char*>(buffer.bytes()), buffer.byte_length()};
return item;
}
HASH_HashType WebCryptoAlgorithmToNSSHashType(
blink::WebCryptoAlgorithmId algorithm) {
switch (algorithm) {
case blink::WebCryptoAlgorithmIdSha1:
return HASH_AlgSHA1;
case blink::WebCryptoAlgorithmIdSha256:
return HASH_AlgSHA256;
case blink::WebCryptoAlgorithmIdSha384:
return HASH_AlgSHA384;
case blink::WebCryptoAlgorithmIdSha512:
return HASH_AlgSHA512;
default:
// Not a digest algorithm.
return HASH_AlgNULL;
}
}
CK_MECHANISM_TYPE WebCryptoHashToHMACMechanism(
const blink::WebCryptoAlgorithm& algorithm) {
switch (algorithm.id()) {
case blink::WebCryptoAlgorithmIdSha1:
return CKM_SHA_1_HMAC;
case blink::WebCryptoAlgorithmIdSha256:
return CKM_SHA256_HMAC;
case blink::WebCryptoAlgorithmIdSha384:
return CKM_SHA384_HMAC;
case blink::WebCryptoAlgorithmIdSha512:
return CKM_SHA512_HMAC;
default:
// Not a supported algorithm.
return CKM_INVALID_MECHANISM;
}
}
CK_MECHANISM_TYPE WebCryptoHashToDigestMechanism(
const blink::WebCryptoAlgorithm& algorithm) {
switch (algorithm.id()) {
case blink::WebCryptoAlgorithmIdSha1:
return CKM_SHA_1;
case blink::WebCryptoAlgorithmIdSha256:
return CKM_SHA256;
case blink::WebCryptoAlgorithmIdSha384:
return CKM_SHA384;
case blink::WebCryptoAlgorithmIdSha512:
return CKM_SHA512;
default:
// Not a supported algorithm.
return CKM_INVALID_MECHANISM;
}
}
CK_MECHANISM_TYPE WebCryptoHashToMGFMechanism(
const blink::WebCryptoAlgorithm& algorithm) {
switch (algorithm.id()) {
case blink::WebCryptoAlgorithmIdSha1:
return CKG_MGF1_SHA1;
case blink::WebCryptoAlgorithmIdSha256:
return CKG_MGF1_SHA256;
case blink::WebCryptoAlgorithmIdSha384:
return CKG_MGF1_SHA384;
case blink::WebCryptoAlgorithmIdSha512:
return CKG_MGF1_SHA512;
default:
return CKM_INVALID_MECHANISM;
}
}
bool InitializeRsaOaepParams(const blink::WebCryptoAlgorithm& hash,
const CryptoData& label,
CK_RSA_PKCS_OAEP_PARAMS* oaep_params) {
oaep_params->source = CKZ_DATA_SPECIFIED;
oaep_params->pSourceData = const_cast<unsigned char*>(label.bytes());
oaep_params->ulSourceDataLen = label.byte_length();
oaep_params->mgf = WebCryptoHashToMGFMechanism(hash);
oaep_params->hashAlg = WebCryptoHashToDigestMechanism(hash);
if (oaep_params->mgf == CKM_INVALID_MECHANISM ||
oaep_params->hashAlg == CKM_INVALID_MECHANISM) {
return false;
}
return true;
}
Status AesCbcEncryptDecrypt(EncryptOrDecrypt mode,
SymKey* key,
const CryptoData& iv,
const CryptoData& data,
std::vector<uint8>* buffer) {
CK_ATTRIBUTE_TYPE operation = (mode == ENCRYPT) ? CKA_ENCRYPT : CKA_DECRYPT;
SECItem iv_item = MakeSECItemForBuffer(iv);
crypto::ScopedSECItem param(PK11_ParamFromIV(CKM_AES_CBC_PAD, &iv_item));
if (!param)
return Status::OperationError();
crypto::ScopedPK11Context context(PK11_CreateContextBySymKey(
CKM_AES_CBC_PAD, operation, key->key(), param.get()));
if (!context.get())
return Status::OperationError();
// Oddly PK11_CipherOp takes input and output lengths as "int" rather than
// "unsigned int". Do some checks now to avoid integer overflowing.
if (data.byte_length() >= INT_MAX - AES_BLOCK_SIZE) {
// TODO(eroman): Handle this by chunking the input fed into NSS. Right now
// it doesn't make much difference since the one-shot API would end up
// blowing out the memory and crashing anyway.
return Status::ErrorDataTooLarge();
}
// PK11_CipherOp does an invalid memory access when given empty decryption
// input, or input which is not a multiple of the block size. See also
// https://bugzilla.mozilla.com/show_bug.cgi?id=921687.
if (operation == CKA_DECRYPT &&
(data.byte_length() == 0 || (data.byte_length() % AES_BLOCK_SIZE != 0))) {
return Status::OperationError();
}
// TODO(eroman): Refine the output buffer size. It can be computed exactly for
// encryption, and can be smaller for decryption.
unsigned int output_max_len = data.byte_length() + AES_BLOCK_SIZE;
CHECK_GT(output_max_len, data.byte_length());
buffer->resize(output_max_len);
unsigned char* buffer_data = Uint8VectorStart(buffer);
int output_len;
if (SECSuccess != PK11_CipherOp(context.get(),
buffer_data,
&output_len,
buffer->size(),
data.bytes(),
data.byte_length())) {
return Status::OperationError();
}
unsigned int final_output_chunk_len;
if (SECSuccess != PK11_DigestFinal(context.get(),
buffer_data + output_len,
&final_output_chunk_len,
output_max_len - output_len)) {
return Status::OperationError();
}
buffer->resize(final_output_chunk_len + output_len);
return Status::Success();
}
// Helper to either encrypt or decrypt for AES-GCM. The result of encryption is
// the concatenation of the ciphertext and the authentication tag. Similarly,
// this is the expectation for the input to decryption.
Status AesGcmEncryptDecrypt(EncryptOrDecrypt mode,
SymKey* key,
const CryptoData& data,
const CryptoData& iv,
const CryptoData& additional_data,
unsigned int tag_length_bits,
std::vector<uint8>* buffer) {
Status status = NssSupportsAesGcm();
if (status.IsError())
return status;
unsigned int tag_length_bytes = tag_length_bits / 8;
CK_GCM_PARAMS gcm_params = {0};
gcm_params.pIv = const_cast<unsigned char*>(iv.bytes());
gcm_params.ulIvLen = iv.byte_length();
gcm_params.pAAD = const_cast<unsigned char*>(additional_data.bytes());
gcm_params.ulAADLen = additional_data.byte_length();
gcm_params.ulTagBits = tag_length_bits;
SECItem param;
param.type = siBuffer;
param.data = reinterpret_cast<unsigned char*>(&gcm_params);
param.len = sizeof(gcm_params);
unsigned int buffer_size = 0;
// Calculate the output buffer size.
if (mode == ENCRYPT) {
// TODO(eroman): This is ugly, abstract away the safe integer arithmetic.
if (data.byte_length() > (UINT_MAX - tag_length_bytes))
return Status::ErrorDataTooLarge();
buffer_size = data.byte_length() + tag_length_bytes;
} else {
// TODO(eroman): In theory the buffer allocated for the plain text should be
// sized as |data.byte_length() - tag_length_bytes|.
//
// However NSS has a bug whereby it will fail if the output buffer size is
// not at least as large as the ciphertext:
//
// https://bugzilla.mozilla.org/show_bug.cgi?id=%20853674
//
// From the analysis of that bug it looks like it might be safe to pass a
// correctly sized buffer but lie about its size. Since resizing the
// WebCryptoArrayBuffer is expensive that hack may be worth looking into.
buffer_size = data.byte_length();
}
buffer->resize(buffer_size);
unsigned char* buffer_data = Uint8VectorStart(buffer);
PK11_EncryptDecryptFunction func =
(mode == ENCRYPT) ? g_nss_runtime_support.Get().pk11_encrypt_func()
: g_nss_runtime_support.Get().pk11_decrypt_func();
unsigned int output_len = 0;
SECStatus result = func(key->key(),
CKM_AES_GCM,
&param,
buffer_data,
&output_len,
buffer->size(),
data.bytes(),
data.byte_length());
if (result != SECSuccess)
return Status::OperationError();
// Unfortunately the buffer needs to be shrunk for decryption (see the NSS bug
// above).
buffer->resize(output_len);
return Status::Success();
}
CK_MECHANISM_TYPE WebCryptoAlgorithmToGenMechanism(
const blink::WebCryptoAlgorithm& algorithm) {
switch (algorithm.id()) {
case blink::WebCryptoAlgorithmIdAesCbc:
case blink::WebCryptoAlgorithmIdAesGcm:
case blink::WebCryptoAlgorithmIdAesKw:
return CKM_AES_KEY_GEN;
case blink::WebCryptoAlgorithmIdHmac:
return WebCryptoHashToHMACMechanism(algorithm.hmacKeyGenParams()->hash());
default:
return CKM_INVALID_MECHANISM;
}
}
bool CreatePublicKeyAlgorithm(const blink::WebCryptoAlgorithm& algorithm,
SECKEYPublicKey* key,
blink::WebCryptoKeyAlgorithm* key_algorithm) {
// TODO(eroman): What about other key types rsaPss, rsaOaep.
if (!key || key->keyType != rsaKey)
return false;
unsigned int modulus_length_bits = SECKEY_PublicKeyStrength(key) * 8;
CryptoData public_exponent(key->u.rsa.publicExponent.data,
key->u.rsa.publicExponent.len);
switch (algorithm.paramsType()) {
case blink::WebCryptoAlgorithmParamsTypeRsaHashedImportParams:
case blink::WebCryptoAlgorithmParamsTypeRsaHashedKeyGenParams:
*key_algorithm = blink::WebCryptoKeyAlgorithm::createRsaHashed(
algorithm.id(),
modulus_length_bits,
public_exponent.bytes(),
public_exponent.byte_length(),
GetInnerHashAlgorithm(algorithm).id());
return true;
default:
return false;
}
}
bool CreatePrivateKeyAlgorithm(const blink::WebCryptoAlgorithm& algorithm,
SECKEYPrivateKey* key,
blink::WebCryptoKeyAlgorithm* key_algorithm) {
crypto::ScopedSECKEYPublicKey public_key(SECKEY_ConvertToPublicKey(key));
return CreatePublicKeyAlgorithm(algorithm, public_key.get(), key_algorithm);
}
// The Default IV for AES-KW. See http://www.ietf.org/rfc/rfc3394.txt
// Section 2.2.3.1.
// TODO(padolph): Move to common place to be shared with OpenSSL implementation.
const unsigned char kAesIv[] = {0xA6, 0xA6, 0xA6, 0xA6, 0xA6, 0xA6, 0xA6, 0xA6};
// Sets NSS CK_MECHANISM_TYPE and CK_FLAGS corresponding to the input Web Crypto
// algorithm ID.
Status WebCryptoAlgorithmToNssMechFlags(
const blink::WebCryptoAlgorithm& algorithm,
CK_MECHANISM_TYPE* mechanism,
CK_FLAGS* flags) {
// Flags are verified at the Blink layer; here the flags are set to all
// possible operations of a key for the input algorithm type.
switch (algorithm.id()) {
case blink::WebCryptoAlgorithmIdHmac: {
const blink::WebCryptoAlgorithm hash = GetInnerHashAlgorithm(algorithm);
*mechanism = WebCryptoHashToHMACMechanism(hash);
if (*mechanism == CKM_INVALID_MECHANISM)
return Status::ErrorUnsupported();
*flags = CKF_SIGN | CKF_VERIFY;
return Status::Success();
}
case blink::WebCryptoAlgorithmIdAesCbc: {
*mechanism = CKM_AES_CBC;
*flags = CKF_ENCRYPT | CKF_DECRYPT;
return Status::Success();
}
case blink::WebCryptoAlgorithmIdAesKw: {
*mechanism = CKM_NSS_AES_KEY_WRAP;
*flags = CKF_WRAP | CKF_WRAP;
return Status::Success();
}
case blink::WebCryptoAlgorithmIdAesGcm: {
Status status = NssSupportsAesGcm();
if (status.IsError())
return status;
*mechanism = CKM_AES_GCM;
*flags = CKF_ENCRYPT | CKF_DECRYPT;
return Status::Success();
}
default:
return Status::ErrorUnsupported();
}
}
Status DoUnwrapSymKeyAesKw(const CryptoData& wrapped_key_data,
SymKey* wrapping_key,
CK_MECHANISM_TYPE mechanism,
CK_FLAGS flags,
crypto::ScopedPK11SymKey* unwrapped_key) {
DCHECK_GE(wrapped_key_data.byte_length(), 24u);
DCHECK_EQ(wrapped_key_data.byte_length() % 8, 0u);
SECItem iv_item = MakeSECItemForBuffer(CryptoData(kAesIv, sizeof(kAesIv)));
crypto::ScopedSECItem param_item(
PK11_ParamFromIV(CKM_NSS_AES_KEY_WRAP, &iv_item));
if (!param_item)
return Status::ErrorUnexpected();
SECItem cipher_text = MakeSECItemForBuffer(wrapped_key_data);
// The plaintext length is always 64 bits less than the data size.
const unsigned int plaintext_length = wrapped_key_data.byte_length() - 8;
#if defined(USE_NSS)
// Part of workaround for
// https://bugzilla.mozilla.org/show_bug.cgi?id=981170. See the explanation
// later in this function.
PORT_SetError(0);
#endif
crypto::ScopedPK11SymKey new_key(
PK11_UnwrapSymKeyWithFlags(wrapping_key->key(),
CKM_NSS_AES_KEY_WRAP,
param_item.get(),
&cipher_text,
mechanism,
CKA_FLAGS_ONLY,
plaintext_length,
flags));
// TODO(padolph): Use NSS PORT_GetError() and friends to report a more
// accurate error, providing if doesn't leak any information to web pages
// about other web crypto users, key details, etc.
if (!new_key)
return Status::OperationError();
#if defined(USE_NSS)
// Workaround for https://bugzilla.mozilla.org/show_bug.cgi?id=981170
// which was fixed in NSS 3.16.0.
// If unwrap fails, NSS nevertheless returns a valid-looking PK11SymKey,
// with a reasonable length but with key data pointing to uninitialized
// memory.
// To understand this workaround see the fix for 981170:
// https://hg.mozilla.org/projects/nss/rev/753bb69e543c
if (!NSS_VersionCheck("3.16") && PORT_GetError() == SEC_ERROR_BAD_DATA)
return Status::OperationError();
#endif
*unwrapped_key = new_key.Pass();
return Status::Success();
}
void CopySECItemToVector(const SECItem& item, std::vector<uint8>* out) {
out->assign(item.data, item.data + item.len);
}
// From PKCS#1 [http://tools.ietf.org/html/rfc3447]:
//
// RSAPrivateKey ::= SEQUENCE {
// version Version,
// modulus INTEGER, -- n
// publicExponent INTEGER, -- e
// privateExponent INTEGER, -- d
// prime1 INTEGER, -- p
// prime2 INTEGER, -- q
// exponent1 INTEGER, -- d mod (p-1)
// exponent2 INTEGER, -- d mod (q-1)
// coefficient INTEGER, -- (inverse of q) mod p
// otherPrimeInfos OtherPrimeInfos OPTIONAL
// }
//
// Note that otherPrimeInfos is only applicable for version=1. Since NSS
// doesn't use multi-prime can safely use version=0.
struct RSAPrivateKey {
SECItem version;
SECItem modulus;
SECItem public_exponent;
SECItem private_exponent;
SECItem prime1;
SECItem prime2;
SECItem exponent1;
SECItem exponent2;
SECItem coefficient;
};
// The system NSS library doesn't have the new PK11_ExportDERPrivateKeyInfo
// function yet (https://bugzilla.mozilla.org/show_bug.cgi?id=519255). So we
// provide a fallback implementation.
#if defined(USE_NSS)
const SEC_ASN1Template RSAPrivateKeyTemplate[] = {
{SEC_ASN1_SEQUENCE, 0, NULL, sizeof(RSAPrivateKey)},
{SEC_ASN1_INTEGER, offsetof(RSAPrivateKey, version)},
{SEC_ASN1_INTEGER, offsetof(RSAPrivateKey, modulus)},
{SEC_ASN1_INTEGER, offsetof(RSAPrivateKey, public_exponent)},
{SEC_ASN1_INTEGER, offsetof(RSAPrivateKey, private_exponent)},
{SEC_ASN1_INTEGER, offsetof(RSAPrivateKey, prime1)},
{SEC_ASN1_INTEGER, offsetof(RSAPrivateKey, prime2)},
{SEC_ASN1_INTEGER, offsetof(RSAPrivateKey, exponent1)},
{SEC_ASN1_INTEGER, offsetof(RSAPrivateKey, exponent2)},
{SEC_ASN1_INTEGER, offsetof(RSAPrivateKey, coefficient)},
{0}};
#endif // defined(USE_NSS)
// On success |value| will be filled with data which must be freed by
// SECITEM_FreeItem(value, PR_FALSE);
bool ReadUint(SECKEYPrivateKey* key,
CK_ATTRIBUTE_TYPE attribute,
SECItem* value) {
SECStatus rv = PK11_ReadRawAttribute(PK11_TypePrivKey, key, attribute, value);
// PK11_ReadRawAttribute() returns items of type siBuffer. However in order
// for the ASN.1 encoding to be correct, the items must be of type
// siUnsignedInteger.
value->type = siUnsignedInteger;
return rv == SECSuccess;
}
// Fills |out| with the RSA private key properties. Returns true on success.
// Regardless of the return value, the caller must invoke FreeRSAPrivateKey()
// to free up any allocated memory.
//
// The passed in RSAPrivateKey must be zero-initialized.
bool InitRSAPrivateKey(SECKEYPrivateKey* key, RSAPrivateKey* out) {
if (key->keyType != rsaKey)
return false;
// Everything should be zero-ed out. These are just some spot checks.
DCHECK(!out->version.data);
DCHECK(!out->version.len);
DCHECK(!out->modulus.data);
DCHECK(!out->modulus.len);
// Always use version=0 since not using multi-prime.
if (!SEC_ASN1EncodeInteger(NULL, &out->version, 0))
return false;
if (!ReadUint(key, CKA_MODULUS, &out->modulus))
return false;
if (!ReadUint(key, CKA_PUBLIC_EXPONENT, &out->public_exponent))
return false;
if (!ReadUint(key, CKA_PRIVATE_EXPONENT, &out->private_exponent))
return false;
if (!ReadUint(key, CKA_PRIME_1, &out->prime1))
return false;
if (!ReadUint(key, CKA_PRIME_2, &out->prime2))
return false;
if (!ReadUint(key, CKA_EXPONENT_1, &out->exponent1))
return false;
if (!ReadUint(key, CKA_EXPONENT_2, &out->exponent2))
return false;
if (!ReadUint(key, CKA_COEFFICIENT, &out->coefficient))
return false;
return true;
}
struct FreeRsaPrivateKey {
void operator()(RSAPrivateKey* out) {
SECITEM_FreeItem(&out->version, PR_FALSE);
SECITEM_FreeItem(&out->modulus, PR_FALSE);
SECITEM_FreeItem(&out->public_exponent, PR_FALSE);
SECITEM_FreeItem(&out->private_exponent, PR_FALSE);
SECITEM_FreeItem(&out->prime1, PR_FALSE);
SECITEM_FreeItem(&out->prime2, PR_FALSE);
SECITEM_FreeItem(&out->exponent1, PR_FALSE);
SECITEM_FreeItem(&out->exponent2, PR_FALSE);
SECITEM_FreeItem(&out->coefficient, PR_FALSE);
}
};
} // namespace
class DigestorNSS : public blink::WebCryptoDigestor {
public:
explicit DigestorNSS(blink::WebCryptoAlgorithmId algorithm_id)
: hash_context_(NULL), algorithm_id_(algorithm_id) {}
virtual ~DigestorNSS() {
if (!hash_context_)
return;
HASH_Destroy(hash_context_);
hash_context_ = NULL;
}
virtual bool consume(const unsigned char* data, unsigned int size) {
return ConsumeWithStatus(data, size).IsSuccess();
}
Status ConsumeWithStatus(const unsigned char* data, unsigned int size) {
// Initialize everything if the object hasn't been initialized yet.
if (!hash_context_) {
Status error = Init();
if (!error.IsSuccess())
return error;
}
HASH_Update(hash_context_, data, size);
return Status::Success();
}
virtual bool finish(unsigned char*& result_data,
unsigned int& result_data_size) {
Status error = FinishInternal(result_, &result_data_size);
if (!error.IsSuccess())
return false;
result_data = result_;
return true;
}
Status FinishWithVectorAndStatus(std::vector<uint8>* result) {
if (!hash_context_)
return Status::ErrorUnexpected();
unsigned int result_length = HASH_ResultLenContext(hash_context_);
result->resize(result_length);
unsigned char* digest = Uint8VectorStart(result);
unsigned int digest_size; // ignored
return FinishInternal(digest, &digest_size);
}
private:
Status Init() {
HASH_HashType hash_type = WebCryptoAlgorithmToNSSHashType(algorithm_id_);
if (hash_type == HASH_AlgNULL)
return Status::ErrorUnsupported();
hash_context_ = HASH_Create(hash_type);
if (!hash_context_)
return Status::OperationError();
HASH_Begin(hash_context_);
return Status::Success();
}
Status FinishInternal(unsigned char* result, unsigned int* result_size) {
if (!hash_context_) {
Status error = Init();
if (!error.IsSuccess())
return error;
}
unsigned int hash_result_length = HASH_ResultLenContext(hash_context_);
DCHECK_LE(hash_result_length, static_cast<size_t>(HASH_LENGTH_MAX));
HASH_End(hash_context_, result, result_size, hash_result_length);
if (*result_size != hash_result_length)
return Status::ErrorUnexpected();
return Status::Success();
}
HASHContext* hash_context_;
blink::WebCryptoAlgorithmId algorithm_id_;
unsigned char result_[HASH_LENGTH_MAX];
};
Status ImportKeyRaw(const blink::WebCryptoAlgorithm& algorithm,
const CryptoData& key_data,
bool extractable,
blink::WebCryptoKeyUsageMask usage_mask,
blink::WebCryptoKey* key) {
DCHECK(!algorithm.isNull());
CK_MECHANISM_TYPE mechanism = CKM_INVALID_MECHANISM;
CK_FLAGS flags = 0;
Status status =
WebCryptoAlgorithmToNssMechFlags(algorithm, &mechanism, &flags);
if (status.IsError())
return status;
SECItem key_item = MakeSECItemForBuffer(key_data);
crypto::ScopedPK11Slot slot(PK11_GetInternalSlot());
crypto::ScopedPK11SymKey pk11_sym_key(
PK11_ImportSymKeyWithFlags(slot.get(),
mechanism,
PK11_OriginUnwrap,
CKA_FLAGS_ONLY,
&key_item,
flags,
false,
NULL));
if (!pk11_sym_key.get())
return Status::OperationError();
blink::WebCryptoKeyAlgorithm key_algorithm;
if (!CreateSecretKeyAlgorithm(
algorithm, key_data.byte_length(), &key_algorithm))
return Status::ErrorUnexpected();
scoped_ptr<SymKey> key_handle;
status = SymKey::Create(pk11_sym_key.Pass(), &key_handle);
if (status.IsError())
return status;
*key = blink::WebCryptoKey::create(key_handle.release(),
blink::WebCryptoKeyTypeSecret,
extractable,
key_algorithm,
usage_mask);
return Status::Success();
}
Status ExportKeyRaw(SymKey* key, std::vector<uint8>* buffer) {
if (PK11_ExtractKeyValue(key->key()) != SECSuccess)
return Status::OperationError();
// http://crbug.com/366427: the spec does not define any other failures for
// exporting, so none of the subsequent errors are spec compliant.
const SECItem* key_data = PK11_GetKeyData(key->key());
if (!key_data)
return Status::OperationError();
buffer->assign(key_data->data, key_data->data + key_data->len);
return Status::Success();
}
namespace {
typedef scoped_ptr<CERTSubjectPublicKeyInfo,
crypto::NSSDestroyer<CERTSubjectPublicKeyInfo,
SECKEY_DestroySubjectPublicKeyInfo> >
ScopedCERTSubjectPublicKeyInfo;
// Validates an NSS KeyType against a WebCrypto import algorithm.
bool ValidateNssKeyTypeAgainstInputAlgorithm(
KeyType key_type,
const blink::WebCryptoAlgorithm& algorithm) {
switch (key_type) {
case rsaKey:
return IsAlgorithmRsa(algorithm.id());
case dsaKey:
case ecKey:
case rsaPssKey:
case rsaOaepKey:
// TODO(padolph): Handle other key types.
break;
default:
break;
}
return false;
}
} // namespace
Status ImportKeySpki(const blink::WebCryptoAlgorithm& algorithm,
const CryptoData& key_data,
bool extractable,
blink::WebCryptoKeyUsageMask usage_mask,
blink::WebCryptoKey* key) {
Status status = NssSupportsKeyImport(algorithm.id());
if (status.IsError())
return status;
DCHECK(key);
if (!key_data.byte_length())
return Status::ErrorImportEmptyKeyData();
DCHECK(key_data.bytes());
// The binary blob 'key_data' is expected to be a DER-encoded ASN.1 Subject
// Public Key Info. Decode this to a CERTSubjectPublicKeyInfo.
SECItem spki_item = MakeSECItemForBuffer(key_data);
const ScopedCERTSubjectPublicKeyInfo spki(
SECKEY_DecodeDERSubjectPublicKeyInfo(&spki_item));
if (!spki)
return Status::DataError();
crypto::ScopedSECKEYPublicKey sec_public_key(
SECKEY_ExtractPublicKey(spki.get()));
if (!sec_public_key)
return Status::DataError();
const KeyType sec_key_type = SECKEY_GetPublicKeyType(sec_public_key.get());
if (!ValidateNssKeyTypeAgainstInputAlgorithm(sec_key_type, algorithm))
return Status::DataError();
blink::WebCryptoKeyAlgorithm key_algorithm;
if (!CreatePublicKeyAlgorithm(
algorithm, sec_public_key.get(), &key_algorithm))
return Status::ErrorUnexpected();
scoped_ptr<PublicKey> key_handle;
status = PublicKey::Create(sec_public_key.Pass(), &key_handle);
if (status.IsError())
return status;
*key = blink::WebCryptoKey::create(key_handle.release(),
blink::WebCryptoKeyTypePublic,
extractable,
key_algorithm,
usage_mask);
return Status::Success();
}
Status ExportKeySpki(PublicKey* key, std::vector<uint8>* buffer) {
const crypto::ScopedSECItem spki_der(
SECKEY_EncodeDERSubjectPublicKeyInfo(key->key()));
// http://crbug.com/366427: the spec does not define any other failures for
// exporting, so none of the subsequent errors are spec compliant.
if (!spki_der)
return Status::OperationError();
DCHECK(spki_der->data);
DCHECK(spki_der->len);
buffer->assign(spki_der->data, spki_der->data + spki_der->len);
return Status::Success();
}
Status ExportRsaPublicKey(PublicKey* key,
std::vector<uint8>* modulus,
std::vector<uint8>* public_exponent) {
DCHECK(key);
DCHECK(key->key());
if (key->key()->keyType != rsaKey)
return Status::ErrorUnsupported();
CopySECItemToVector(key->key()->u.rsa.modulus, modulus);
CopySECItemToVector(key->key()->u.rsa.publicExponent, public_exponent);
if (modulus->empty() || public_exponent->empty())
return Status::ErrorUnexpected();
return Status::Success();
}
void AssignVectorFromSecItem(const SECItem& item, std::vector<uint8>* output) {
output->assign(item.data, item.data + item.len);
}
Status ExportRsaPrivateKey(PrivateKey* key,
std::vector<uint8>* modulus,
std::vector<uint8>* public_exponent,
std::vector<uint8>* private_exponent,
std::vector<uint8>* prime1,
std::vector<uint8>* prime2,
std::vector<uint8>* exponent1,
std::vector<uint8>* exponent2,
std::vector<uint8>* coefficient) {
RSAPrivateKey key_props = {};
scoped_ptr<RSAPrivateKey, FreeRsaPrivateKey> free_private_key(&key_props);
if (!InitRSAPrivateKey(key->key(), &key_props))
return Status::OperationError();
AssignVectorFromSecItem(key_props.modulus, modulus);
AssignVectorFromSecItem(key_props.public_exponent, public_exponent);
AssignVectorFromSecItem(key_props.private_exponent, private_exponent);
AssignVectorFromSecItem(key_props.prime1, prime1);
AssignVectorFromSecItem(key_props.prime2, prime2);
AssignVectorFromSecItem(key_props.exponent1, exponent1);
AssignVectorFromSecItem(key_props.exponent2, exponent2);
AssignVectorFromSecItem(key_props.coefficient, coefficient);
return Status::Success();
}
Status ExportKeyPkcs8(PrivateKey* key,
const blink::WebCryptoKeyAlgorithm& key_algorithm,
std::vector<uint8>* buffer) {
// TODO(eroman): Support other RSA key types as they are added to Blink.
if (key_algorithm.id() != blink::WebCryptoAlgorithmIdRsaSsaPkcs1v1_5 &&
key_algorithm.id() != blink::WebCryptoAlgorithmIdRsaOaep)
return Status::ErrorUnsupported();
// TODO(rsleevi): Implement OAEP support according to the spec.
#if defined(USE_NSS)
// PK11_ExportDERPrivateKeyInfo isn't available. Use our fallback code.
const SECOidTag algorithm = SEC_OID_PKCS1_RSA_ENCRYPTION;
const int kPrivateKeyInfoVersion = 0;
SECKEYPrivateKeyInfo private_key_info = {};
RSAPrivateKey rsa_private_key = {};
scoped_ptr<RSAPrivateKey, FreeRsaPrivateKey> free_private_key(
&rsa_private_key);
// http://crbug.com/366427: the spec does not define any other failures for
// exporting, so none of the subsequent errors are spec compliant.
if (!InitRSAPrivateKey(key->key(), &rsa_private_key))
return Status::OperationError();
crypto::ScopedPLArenaPool arena(PORT_NewArena(DER_DEFAULT_CHUNKSIZE));
if (!arena.get())
return Status::OperationError();
if (!SEC_ASN1EncodeItem(arena.get(),
&private_key_info.privateKey,
&rsa_private_key,
RSAPrivateKeyTemplate))
return Status::OperationError();
if (SECSuccess !=
SECOID_SetAlgorithmID(
arena.get(), &private_key_info.algorithm, algorithm, NULL))
return Status::OperationError();
if (!SEC_ASN1EncodeInteger(
arena.get(), &private_key_info.version, kPrivateKeyInfoVersion))
return Status::OperationError();
crypto::ScopedSECItem encoded_key(
SEC_ASN1EncodeItem(NULL,
NULL,
&private_key_info,
SEC_ASN1_GET(SECKEY_PrivateKeyInfoTemplate)));
#else // defined(USE_NSS)
crypto::ScopedSECItem encoded_key(
PK11_ExportDERPrivateKeyInfo(key->key(), NULL));
#endif // defined(USE_NSS)
if (!encoded_key.get())
return Status::OperationError();
buffer->assign(encoded_key->data, encoded_key->data + encoded_key->len);
return Status::Success();
}
Status ImportKeyPkcs8(const blink::WebCryptoAlgorithm& algorithm,
const CryptoData& key_data,
bool extractable,
blink::WebCryptoKeyUsageMask usage_mask,
blink::WebCryptoKey* key) {
Status status = NssSupportsKeyImport(algorithm.id());
if (status.IsError())
return status;
DCHECK(key);
if (!key_data.byte_length())
return Status::ErrorImportEmptyKeyData();
DCHECK(key_data.bytes());
// The binary blob 'key_data' is expected to be a DER-encoded ASN.1 PKCS#8
// private key info object.
SECItem pki_der = MakeSECItemForBuffer(key_data);
SECKEYPrivateKey* seckey_private_key = NULL;
crypto::ScopedPK11Slot slot(PK11_GetInternalSlot());
if (PK11_ImportDERPrivateKeyInfoAndReturnKey(slot.get(),
&pki_der,
NULL, // nickname
NULL, // publicValue
false, // isPerm
false, // isPrivate
KU_ALL, // usage
&seckey_private_key,
NULL) != SECSuccess) {
return Status::DataError();
}
DCHECK(seckey_private_key);
crypto::ScopedSECKEYPrivateKey private_key(seckey_private_key);
const KeyType sec_key_type = SECKEY_GetPrivateKeyType(private_key.get());
if (!ValidateNssKeyTypeAgainstInputAlgorithm(sec_key_type, algorithm))
return Status::DataError();
blink::WebCryptoKeyAlgorithm key_algorithm;
if (!CreatePrivateKeyAlgorithm(algorithm, private_key.get(), &key_algorithm))
return Status::ErrorUnexpected();
scoped_ptr<PrivateKey> key_handle;
status = PrivateKey::Create(private_key.Pass(), key_algorithm, &key_handle);
if (status.IsError())
return status;
*key = blink::WebCryptoKey::create(key_handle.release(),
blink::WebCryptoKeyTypePrivate,
extractable,
key_algorithm,
usage_mask);
return Status::Success();
}
// -----------------------------------
// Hmac
// -----------------------------------
Status SignHmac(SymKey* key,
const blink::WebCryptoAlgorithm& hash,
const CryptoData& data,
std::vector<uint8>* buffer) {
DCHECK_EQ(PK11_GetMechanism(key->key()), WebCryptoHashToHMACMechanism(hash));
SECItem param_item = {siBuffer, NULL, 0};
SECItem data_item = MakeSECItemForBuffer(data);
// First call is to figure out the length.
SECItem signature_item = {siBuffer, NULL, 0};
if (PK11_SignWithSymKey(key->key(),
PK11_GetMechanism(key->key()),
&param_item,
&signature_item,
&data_item) != SECSuccess) {
return Status::OperationError();
}
DCHECK_NE(0u, signature_item.len);
buffer->resize(signature_item.len);
signature_item.data = Uint8VectorStart(buffer);
if (PK11_SignWithSymKey(key->key(),
PK11_GetMechanism(key->key()),
&param_item,
&signature_item,
&data_item) != SECSuccess) {
return Status::OperationError();
}
DCHECK_EQ(buffer->size(), signature_item.len);
return Status::Success();
}
// -----------------------------------
// RsaOaep
// -----------------------------------
Status EncryptRsaOaep(PublicKey* key,
const blink::WebCryptoAlgorithm& hash,
const CryptoData& label,
const CryptoData& data,
std::vector<uint8>* buffer) {
Status status = NssSupportsRsaOaep();
if (status.IsError())
return status;
CK_RSA_PKCS_OAEP_PARAMS oaep_params = {0};
if (!InitializeRsaOaepParams(hash, label, &oaep_params))
return Status::ErrorUnsupported();
SECItem param;
param.type = siBuffer;
param.data = reinterpret_cast<unsigned char*>(&oaep_params);
param.len = sizeof(oaep_params);
buffer->resize(SECKEY_PublicKeyStrength(key->key()));
unsigned char* buffer_data = Uint8VectorStart(buffer);
unsigned int output_len;
if (g_nss_runtime_support.Get().pk11_pub_encrypt_func()(key->key(),
CKM_RSA_PKCS_OAEP,
&param,
buffer_data,
&output_len,
buffer->size(),
data.bytes(),
data.byte_length(),
NULL) != SECSuccess) {
return Status::OperationError();
}
DCHECK_LE(output_len, buffer->size());
buffer->resize(output_len);
return Status::Success();
}
Status DecryptRsaOaep(PrivateKey* key,
const blink::WebCryptoAlgorithm& hash,
const CryptoData& label,
const CryptoData& data,
std::vector<uint8>* buffer) {
Status status = NssSupportsRsaOaep();
if (status.IsError())
return status;
CK_RSA_PKCS_OAEP_PARAMS oaep_params = {0};
if (!InitializeRsaOaepParams(hash, label, &oaep_params))
return Status::ErrorUnsupported();
SECItem param;
param.type = siBuffer;
param.data = reinterpret_cast<unsigned char*>(&oaep_params);
param.len = sizeof(oaep_params);
const int modulus_length_bytes = PK11_GetPrivateModulusLen(key->key());
if (modulus_length_bytes <= 0)
return Status::ErrorUnexpected();
buffer->resize(modulus_length_bytes);
unsigned char* buffer_data = Uint8VectorStart(buffer);
unsigned int output_len;
if (g_nss_runtime_support.Get().pk11_priv_decrypt_func()(
key->key(),
CKM_RSA_PKCS_OAEP,
&param,
buffer_data,
&output_len,
buffer->size(),
data.bytes(),
data.byte_length()) != SECSuccess) {
return Status::OperationError();
}
DCHECK_LE(output_len, buffer->size());
buffer->resize(output_len);
return Status::Success();
}
// -----------------------------------
// RsaSsaPkcs1v1_5
// -----------------------------------
Status SignRsaSsaPkcs1v1_5(PrivateKey* key,
const blink::WebCryptoAlgorithm& hash,
const CryptoData& data,
std::vector<uint8>* buffer) {
// Pick the NSS signing algorithm by combining RSA-SSA (RSA PKCS1) and the
// inner hash of the input Web Crypto algorithm.
SECOidTag sign_alg_tag;
switch (hash.id()) {
case blink::WebCryptoAlgorithmIdSha1:
sign_alg_tag = SEC_OID_PKCS1_SHA1_WITH_RSA_ENCRYPTION;
break;
case blink::WebCryptoAlgorithmIdSha256:
sign_alg_tag = SEC_OID_PKCS1_SHA256_WITH_RSA_ENCRYPTION;
break;
case blink::WebCryptoAlgorithmIdSha384:
sign_alg_tag = SEC_OID_PKCS1_SHA384_WITH_RSA_ENCRYPTION;
break;
case blink::WebCryptoAlgorithmIdSha512:
sign_alg_tag = SEC_OID_PKCS1_SHA512_WITH_RSA_ENCRYPTION;
break;
default:
return Status::ErrorUnsupported();
}
crypto::ScopedSECItem signature_item(SECITEM_AllocItem(NULL, NULL, 0));
if (SEC_SignData(signature_item.get(),
data.bytes(),
data.byte_length(),
key->key(),
sign_alg_tag) != SECSuccess) {
return Status::OperationError();
}
buffer->assign(signature_item->data,
signature_item->data + signature_item->len);
return Status::Success();
}
Status VerifyRsaSsaPkcs1v1_5(PublicKey* key,
const blink::WebCryptoAlgorithm& hash,
const CryptoData& signature,
const CryptoData& data,
bool* signature_match) {
const SECItem signature_item = MakeSECItemForBuffer(signature);
SECOidTag hash_alg_tag;
switch (hash.id()) {
case blink::WebCryptoAlgorithmIdSha1:
hash_alg_tag = SEC_OID_SHA1;
break;
case blink::WebCryptoAlgorithmIdSha256:
hash_alg_tag = SEC_OID_SHA256;
break;
case blink::WebCryptoAlgorithmIdSha384:
hash_alg_tag = SEC_OID_SHA384;
break;
case blink::WebCryptoAlgorithmIdSha512:
hash_alg_tag = SEC_OID_SHA512;
break;
default:
return Status::ErrorUnsupported();
}
*signature_match =
SECSuccess == VFY_VerifyDataDirect(data.bytes(),
data.byte_length(),
key->key(),
&signature_item,
SEC_OID_PKCS1_RSA_ENCRYPTION,
hash_alg_tag,
NULL,
NULL);
return Status::Success();
}
Status EncryptDecryptAesCbc(EncryptOrDecrypt mode,
SymKey* key,
const CryptoData& data,
const CryptoData& iv,
std::vector<uint8>* buffer) {
// TODO(eroman): Inline.
return AesCbcEncryptDecrypt(mode, key, iv, data, buffer);
}
Status EncryptDecryptAesGcm(EncryptOrDecrypt mode,
SymKey* key,
const CryptoData& data,
const CryptoData& iv,
const CryptoData& additional_data,
unsigned int tag_length_bits,
std::vector<uint8>* buffer) {
// TODO(eroman): Inline.
return AesGcmEncryptDecrypt(
mode, key, data, iv, additional_data, tag_length_bits, buffer);
}
// -----------------------------------
// Key generation
// -----------------------------------
Status GenerateRsaKeyPair(const blink::WebCryptoAlgorithm& algorithm,
bool extractable,
blink::WebCryptoKeyUsageMask public_key_usage_mask,
blink::WebCryptoKeyUsageMask private_key_usage_mask,
unsigned int modulus_length_bits,
unsigned long public_exponent,
blink::WebCryptoKey* public_key,
blink::WebCryptoKey* private_key) {
if (algorithm.id() == blink::WebCryptoAlgorithmIdRsaOaep) {
Status status = NssSupportsRsaOaep();
if (status.IsError())
return status;
}
crypto::ScopedPK11Slot slot(PK11_GetInternalKeySlot());
if (!slot)
return Status::OperationError();
PK11RSAGenParams rsa_gen_params;
// keySizeInBits is a signed type, don't pass in a negative value.
if (modulus_length_bits > INT_MAX)
return Status::OperationError();
rsa_gen_params.keySizeInBits = modulus_length_bits;
rsa_gen_params.pe = public_exponent;
// Flags are verified at the Blink layer; here the flags are set to all
// possible operations for the given key type.
CK_FLAGS operation_flags;
switch (algorithm.id()) {
case blink::WebCryptoAlgorithmIdRsaOaep:
operation_flags = CKF_ENCRYPT | CKF_DECRYPT | CKF_WRAP | CKF_UNWRAP;
break;
case blink::WebCryptoAlgorithmIdRsaSsaPkcs1v1_5:
operation_flags = CKF_SIGN | CKF_VERIFY;
break;
default:
NOTREACHED();
return Status::ErrorUnexpected();
}
const CK_FLAGS operation_flags_mask =
CKF_ENCRYPT | CKF_DECRYPT | CKF_SIGN | CKF_VERIFY | CKF_WRAP | CKF_UNWRAP;
// The private key must be marked as insensitive and extractable, otherwise it
// cannot later be exported in unencrypted form or structured-cloned.
const PK11AttrFlags attribute_flags =
PK11_ATTR_INSENSITIVE | PK11_ATTR_EXTRACTABLE;
// Note: NSS does not generate an sec_public_key if the call below fails,
// so there is no danger of a leaked sec_public_key.
SECKEYPublicKey* sec_public_key = NULL;
crypto::ScopedSECKEYPrivateKey scoped_sec_private_key(
PK11_GenerateKeyPairWithOpFlags(slot.get(),
CKM_RSA_PKCS_KEY_PAIR_GEN,
&rsa_gen_params,
&sec_public_key,
attribute_flags,
operation_flags,
operation_flags_mask,
NULL));
if (!scoped_sec_private_key)
return Status::OperationError();
blink::WebCryptoKeyAlgorithm key_algorithm;
if (!CreatePublicKeyAlgorithm(algorithm, sec_public_key, &key_algorithm))
return Status::ErrorUnexpected();
scoped_ptr<PublicKey> public_key_handle;
Status status = PublicKey::Create(
crypto::ScopedSECKEYPublicKey(sec_public_key), &public_key_handle);
if (status.IsError())
return status;
scoped_ptr<PrivateKey> private_key_handle;
status = PrivateKey::Create(
scoped_sec_private_key.Pass(), key_algorithm, &private_key_handle);
if (status.IsError())
return status;
*public_key = blink::WebCryptoKey::create(public_key_handle.release(),
blink::WebCryptoKeyTypePublic,
true,
key_algorithm,
public_key_usage_mask);
*private_key = blink::WebCryptoKey::create(private_key_handle.release(),
blink::WebCryptoKeyTypePrivate,
extractable,
key_algorithm,
private_key_usage_mask);
return Status::Success();
}
void Init() {
crypto::EnsureNSSInit();
}
Status DigestSha(blink::WebCryptoAlgorithmId algorithm,
const CryptoData& data,
std::vector<uint8>* buffer) {
DigestorNSS digestor(algorithm);
Status error = digestor.ConsumeWithStatus(data.bytes(), data.byte_length());
// http://crbug.com/366427: the spec does not define any other failures for
// digest, so none of the subsequent errors are spec compliant.
if (!error.IsSuccess())
return error;
return digestor.FinishWithVectorAndStatus(buffer);
}
scoped_ptr<blink::WebCryptoDigestor> CreateDigestor(
blink::WebCryptoAlgorithmId algorithm_id) {
return scoped_ptr<blink::WebCryptoDigestor>(new DigestorNSS(algorithm_id));
}
Status GenerateSecretKey(const blink::WebCryptoAlgorithm& algorithm,
bool extractable,
blink::WebCryptoKeyUsageMask usage_mask,
unsigned keylen_bytes,
blink::WebCryptoKey* key) {
CK_MECHANISM_TYPE mech = WebCryptoAlgorithmToGenMechanism(algorithm);
blink::WebCryptoKeyType key_type = blink::WebCryptoKeyTypeSecret;
if (mech == CKM_INVALID_MECHANISM)
return Status::ErrorUnsupported();
crypto::ScopedPK11Slot slot(PK11_GetInternalKeySlot());
if (!slot)
return Status::OperationError();
crypto::ScopedPK11SymKey pk11_key(
PK11_KeyGen(slot.get(), mech, NULL, keylen_bytes, NULL));
if (!pk11_key)
return Status::OperationError();
blink::WebCryptoKeyAlgorithm key_algorithm;
if (!CreateSecretKeyAlgorithm(algorithm, keylen_bytes, &key_algorithm))
return Status::ErrorUnexpected();
scoped_ptr<SymKey> key_handle;
Status status = SymKey::Create(pk11_key.Pass(), &key_handle);
if (status.IsError())
return status;
*key = blink::WebCryptoKey::create(
key_handle.release(), key_type, extractable, key_algorithm, usage_mask);
return Status::Success();
}
Status ImportRsaPublicKey(const blink::WebCryptoAlgorithm& algorithm,
bool extractable,
blink::WebCryptoKeyUsageMask usage_mask,
const CryptoData& modulus_data,
const CryptoData& exponent_data,
blink::WebCryptoKey* key) {
if (!modulus_data.byte_length())
return Status::ErrorImportRsaEmptyModulus();
if (!exponent_data.byte_length())
return Status::ErrorImportRsaEmptyExponent();
DCHECK(modulus_data.bytes());
DCHECK(exponent_data.bytes());
// NSS does not provide a way to create an RSA public key directly from the
// modulus and exponent values, but it can import an DER-encoded ASN.1 blob
// with these values and create the public key from that. The code below
// follows the recommendation described in
// https://developer.mozilla.org/en-US/docs/NSS/NSS_Tech_Notes/nss_tech_note7
// Pack the input values into a struct compatible with NSS ASN.1 encoding, and
// set up an ASN.1 encoder template for it.
struct RsaPublicKeyData {
SECItem modulus;
SECItem exponent;
};
const RsaPublicKeyData pubkey_in = {
{siUnsignedInteger, const_cast<unsigned char*>(modulus_data.bytes()),
modulus_data.byte_length()},
{siUnsignedInteger, const_cast<unsigned char*>(exponent_data.bytes()),
exponent_data.byte_length()}};
const SEC_ASN1Template rsa_public_key_template[] = {
{SEC_ASN1_SEQUENCE, 0, NULL, sizeof(RsaPublicKeyData)},
{SEC_ASN1_INTEGER, offsetof(RsaPublicKeyData, modulus), },
{SEC_ASN1_INTEGER, offsetof(RsaPublicKeyData, exponent), },
{0, }};
// DER-encode the public key.
crypto::ScopedSECItem pubkey_der(
SEC_ASN1EncodeItem(NULL, NULL, &pubkey_in, rsa_public_key_template));
if (!pubkey_der)
return Status::OperationError();
// Import the DER-encoded public key to create an RSA SECKEYPublicKey.
crypto::ScopedSECKEYPublicKey pubkey(
SECKEY_ImportDERPublicKey(pubkey_der.get(), CKK_RSA));
if (!pubkey)
return Status::OperationError();
blink::WebCryptoKeyAlgorithm key_algorithm;
if (!CreatePublicKeyAlgorithm(algorithm, pubkey.get(), &key_algorithm))
return Status::ErrorUnexpected();
scoped_ptr<PublicKey> key_handle;
Status status = PublicKey::Create(pubkey.Pass(), &key_handle);
if (status.IsError())
return status;
*key = blink::WebCryptoKey::create(key_handle.release(),
blink::WebCryptoKeyTypePublic,
extractable,
key_algorithm,
usage_mask);
return Status::Success();
}
struct DestroyGenericObject {
void operator()(PK11GenericObject* o) const {
if (o)
PK11_DestroyGenericObject(o);
}
};
typedef scoped_ptr<PK11GenericObject, DestroyGenericObject>
ScopedPK11GenericObject;
// Helper to add an attribute to a template.
void AddAttribute(CK_ATTRIBUTE_TYPE type,
void* value,
unsigned long length,
std::vector<CK_ATTRIBUTE>* templ) {
CK_ATTRIBUTE attribute = {type, value, length};
templ->push_back(attribute);
}
// Helper to optionally add an attribute to a template, if the provided data is
// non-empty.
void AddOptionalAttribute(CK_ATTRIBUTE_TYPE type,
const CryptoData& data,
std::vector<CK_ATTRIBUTE>* templ) {
if (!data.byte_length())
return;
CK_ATTRIBUTE attribute = {type, const_cast<unsigned char*>(data.bytes()),
data.byte_length()};
templ->push_back(attribute);
}
Status ImportRsaPrivateKey(const blink::WebCryptoAlgorithm& algorithm,
bool extractable,
blink::WebCryptoKeyUsageMask usage_mask,
const CryptoData& modulus,
const CryptoData& public_exponent,
const CryptoData& private_exponent,
const CryptoData& prime1,
const CryptoData& prime2,
const CryptoData& exponent1,
const CryptoData& exponent2,
const CryptoData& coefficient,
blink::WebCryptoKey* key) {
Status status = NssSupportsKeyImport(algorithm.id());
if (status.IsError())
return status;
CK_OBJECT_CLASS obj_class = CKO_PRIVATE_KEY;
CK_KEY_TYPE key_type = CKK_RSA;
CK_BBOOL ck_false = CK_FALSE;
std::vector<CK_ATTRIBUTE> key_template;
AddAttribute(CKA_CLASS, &obj_class, sizeof(obj_class), &key_template);
AddAttribute(CKA_KEY_TYPE, &key_type, sizeof(key_type), &key_template);
AddAttribute(CKA_TOKEN, &ck_false, sizeof(ck_false), &key_template);
AddAttribute(CKA_SENSITIVE, &ck_false, sizeof(ck_false), &key_template);
AddAttribute(CKA_PRIVATE, &ck_false, sizeof(ck_false), &key_template);
// Required properties.
AddOptionalAttribute(CKA_MODULUS, modulus, &key_template);
AddOptionalAttribute(CKA_PUBLIC_EXPONENT, public_exponent, &key_template);
AddOptionalAttribute(CKA_PRIVATE_EXPONENT, private_exponent, &key_template);
// Manufacture a CKA_ID so the created key can be retrieved later as a
// SECKEYPrivateKey using FindKeyByKeyID(). Unfortunately there isn't a more
// direct way to do this in NSS.
//
// For consistency with other NSS key creation methods, set the CKA_ID to
// PK11_MakeIDFromPubKey(). There are some problems with
// this approach:
//
// (1) Prior to NSS 3.16.2, there is no parameter validation when creating
// private keys. It is therefore possible to construct a key using the
// known public modulus, and where all the other parameters are bogus.
// FindKeyByKeyID() returns the first key matching the ID. So this would
// effectively allow an attacker to retrieve a private key of their
// choice.
// TODO(eroman): Once NSS rolls and this is fixed, disallow RSA key
// import on older versions of NSS.
// http://crbug.com/378315
//
// (2) The ID space is shared by different key types. So theoretically
// possible to retrieve a key of the wrong type which has a matching
// CKA_ID. In practice I am told this is not likely except for small key
// sizes, since would require constructing keys with the same public
// data.
//
// (3) FindKeyByKeyID() doesn't necessarily return the object that was just
// created by CreateGenericObject. If the pre-existing key was
// provisioned with flags incompatible with WebCrypto (for instance
// marked sensitive) then this will break things.
SECItem modulus_item = MakeSECItemForBuffer(CryptoData(modulus));
crypto::ScopedSECItem object_id(PK11_MakeIDFromPubKey(&modulus_item));
AddOptionalAttribute(
CKA_ID, CryptoData(object_id->data, object_id->len), &key_template);
// Optional properties (all of these will have been specified or none).
AddOptionalAttribute(CKA_PRIME_1, prime1, &key_template);
AddOptionalAttribute(CKA_PRIME_2, prime2, &key_template);
AddOptionalAttribute(CKA_EXPONENT_1, exponent1, &key_template);
AddOptionalAttribute(CKA_EXPONENT_2, exponent2, &key_template);
AddOptionalAttribute(CKA_COEFFICIENT, coefficient, &key_template);
crypto::ScopedPK11Slot slot(PK11_GetInternalSlot());
ScopedPK11GenericObject key_object(PK11_CreateGenericObject(
slot.get(), &key_template[0], key_template.size(), PR_FALSE));
if (!key_object)
return Status::OperationError();
crypto::ScopedSECKEYPrivateKey private_key_tmp(
PK11_FindKeyByKeyID(slot.get(), object_id.get(), NULL));
// PK11_FindKeyByKeyID() may return a handle to an existing key, rather than
// the object created by PK11_CreateGenericObject().
crypto::ScopedSECKEYPrivateKey private_key(
SECKEY_CopyPrivateKey(private_key_tmp.get()));
if (!private_key)
return Status::OperationError();
blink::WebCryptoKeyAlgorithm key_algorithm;
if (!CreatePrivateKeyAlgorithm(algorithm, private_key.get(), &key_algorithm))
return Status::ErrorUnexpected();
scoped_ptr<PrivateKey> key_handle;
status = PrivateKey::Create(private_key.Pass(), key_algorithm, &key_handle);
if (status.IsError())
return status;
*key = blink::WebCryptoKey::create(key_handle.release(),
blink::WebCryptoKeyTypePrivate,
extractable,
key_algorithm,
usage_mask);
return Status::Success();
}
Status WrapSymKeyAesKw(PK11SymKey* key,
SymKey* wrapping_key,
std::vector<uint8>* buffer) {
// The data size must be at least 16 bytes and a multiple of 8 bytes.
// RFC 3394 does not specify a maximum allowed data length, but since only
// keys are being wrapped in this application (which are small), a reasonable
// max limit is whatever will fit into an unsigned. For the max size test,
// note that AES Key Wrap always adds 8 bytes to the input data size.
const unsigned int input_length = PK11_GetKeyLength(key);
DCHECK_GE(input_length, 16u);
DCHECK((input_length % 8) == 0);
if (input_length > UINT_MAX - 8)
return Status::ErrorDataTooLarge();
SECItem iv_item = MakeSECItemForBuffer(CryptoData(kAesIv, sizeof(kAesIv)));
crypto::ScopedSECItem param_item(
PK11_ParamFromIV(CKM_NSS_AES_KEY_WRAP, &iv_item));
if (!param_item)
return Status::ErrorUnexpected();
const unsigned int output_length = input_length + 8;
buffer->resize(output_length);
SECItem wrapped_key_item = MakeSECItemForBuffer(CryptoData(*buffer));
if (SECSuccess != PK11_WrapSymKey(CKM_NSS_AES_KEY_WRAP,
param_item.get(),
wrapping_key->key(),
key,
&wrapped_key_item)) {
return Status::OperationError();
}
if (output_length != wrapped_key_item.len)
return Status::ErrorUnexpected();
return Status::Success();
}
Status DecryptAesKw(SymKey* wrapping_key,
const CryptoData& data,
std::vector<uint8>* buffer) {
// Due to limitations in the NSS API for the AES-KW algorithm, |data| must be
// temporarily viewed as a symmetric key to be unwrapped (decrypted).
crypto::ScopedPK11SymKey decrypted;
Status status = DoUnwrapSymKeyAesKw(
data, wrapping_key, CKK_GENERIC_SECRET, 0, &decrypted);
if (status.IsError())
return status;
// Once the decrypt is complete, extract the resultant raw bytes from NSS and
// return them to the caller.
if (PK11_ExtractKeyValue(decrypted.get()) != SECSuccess)
return Status::OperationError();
const SECItem* const key_data = PK11_GetKeyData(decrypted.get());
if (!key_data)
return Status::OperationError();
buffer->assign(key_data->data, key_data->data + key_data->len);
return Status::Success();
}
Status EncryptAesKw(SymKey* wrapping_key,
const CryptoData& data,
std::vector<uint8>* buffer) {
// Due to limitations in the NSS API for the AES-KW algorithm, |data| must be
// temporarily viewed as a symmetric key to be wrapped (encrypted).
SECItem data_item = MakeSECItemForBuffer(data);
crypto::ScopedPK11Slot slot(PK11_GetInternalSlot());
crypto::ScopedPK11SymKey data_as_sym_key(PK11_ImportSymKey(slot.get(),
CKK_GENERIC_SECRET,
PK11_OriginUnwrap,
CKA_SIGN,
&data_item,
NULL));
if (!data_as_sym_key)
return Status::OperationError();
return WrapSymKeyAesKw(data_as_sym_key.get(), wrapping_key, buffer);
}
Status EncryptDecryptAesKw(EncryptOrDecrypt mode,
SymKey* wrapping_key,
const CryptoData& data,
std::vector<uint8>* buffer) {
return mode == ENCRYPT ? EncryptAesKw(wrapping_key, data, buffer)
: DecryptAesKw(wrapping_key, data, buffer);
}
} // namespace platform
} // namespace webcrypto
} // namespace content