| // Copyright (c) 2012 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 "crypto/symmetric_key.h" |
| |
| #include <nss.h> |
| #include <pk11pub.h> |
| #include <stddef.h> |
| |
| #include "base/logging.h" |
| #include "crypto/nss_util.h" |
| #include "crypto/scoped_nss_types.h" |
| |
| namespace crypto { |
| |
| SymmetricKey::~SymmetricKey() {} |
| |
| // static |
| SymmetricKey* SymmetricKey::GenerateRandomKey(Algorithm algorithm, |
| size_t key_size_in_bits) { |
| DCHECK_EQ(AES, algorithm); |
| |
| EnsureNSSInit(); |
| |
| // Whitelist supported key sizes to avoid accidentaly relying on |
| // algorithms available in NSS but not BoringSSL and vice |
| // versa. Note that BoringSSL does not support AES-192. |
| if (key_size_in_bits != 128 && key_size_in_bits != 256) |
| return NULL; |
| |
| ScopedPK11Slot slot(PK11_GetInternalSlot()); |
| if (!slot.get()) |
| return NULL; |
| |
| PK11SymKey* sym_key = PK11_KeyGen(slot.get(), CKM_AES_KEY_GEN, NULL, |
| key_size_in_bits / 8, NULL); |
| if (!sym_key) |
| return NULL; |
| |
| return new SymmetricKey(sym_key); |
| } |
| |
| // static |
| SymmetricKey* SymmetricKey::DeriveKeyFromPassword(Algorithm algorithm, |
| const std::string& password, |
| const std::string& salt, |
| size_t iterations, |
| size_t key_size_in_bits) { |
| EnsureNSSInit(); |
| if (salt.empty() || iterations == 0 || key_size_in_bits == 0) |
| return NULL; |
| |
| if (algorithm == AES) { |
| // Whitelist supported key sizes to avoid accidentaly relying on |
| // algorithms available in NSS but not BoringSSL and vice |
| // versa. Note that BoringSSL does not support AES-192. |
| if (key_size_in_bits != 128 && key_size_in_bits != 256) |
| return NULL; |
| } |
| |
| SECItem password_item; |
| password_item.type = siBuffer; |
| password_item.data = reinterpret_cast<unsigned char*>( |
| const_cast<char *>(password.data())); |
| password_item.len = password.size(); |
| |
| SECItem salt_item; |
| salt_item.type = siBuffer; |
| salt_item.data = reinterpret_cast<unsigned char*>( |
| const_cast<char *>(salt.data())); |
| salt_item.len = salt.size(); |
| |
| SECOidTag cipher_algorithm = |
| algorithm == AES ? SEC_OID_AES_256_CBC : SEC_OID_HMAC_SHA1; |
| ScopedSECAlgorithmID alg_id(PK11_CreatePBEV2AlgorithmID(SEC_OID_PKCS5_PBKDF2, |
| cipher_algorithm, |
| SEC_OID_HMAC_SHA1, |
| key_size_in_bits / 8, |
| iterations, |
| &salt_item)); |
| if (!alg_id.get()) |
| return NULL; |
| |
| ScopedPK11Slot slot(PK11_GetInternalSlot()); |
| if (!slot.get()) |
| return NULL; |
| |
| PK11SymKey* sym_key = PK11_PBEKeyGen(slot.get(), alg_id.get(), &password_item, |
| PR_FALSE, NULL); |
| if (!sym_key) |
| return NULL; |
| |
| return new SymmetricKey(sym_key); |
| } |
| |
| // static |
| SymmetricKey* SymmetricKey::Import(Algorithm algorithm, |
| const std::string& raw_key) { |
| EnsureNSSInit(); |
| |
| if (algorithm == AES) { |
| // Whitelist supported key sizes to avoid accidentaly relying on |
| // algorithms available in NSS but not BoringSSL and vice |
| // versa. Note that BoringSSL does not support AES-192. |
| if (raw_key.size() != 128/8 && raw_key.size() != 256/8) |
| return NULL; |
| } |
| |
| CK_MECHANISM_TYPE cipher = |
| algorithm == AES ? CKM_AES_CBC : CKM_SHA_1_HMAC; |
| |
| SECItem key_item; |
| key_item.type = siBuffer; |
| key_item.data = reinterpret_cast<unsigned char*>( |
| const_cast<char *>(raw_key.data())); |
| key_item.len = raw_key.size(); |
| |
| ScopedPK11Slot slot(PK11_GetInternalSlot()); |
| if (!slot.get()) |
| return NULL; |
| |
| // The exact value of the |origin| argument doesn't matter to NSS as long as |
| // it's not PK11_OriginFortezzaHack, so we pass PK11_OriginUnwrap as a |
| // placeholder. |
| PK11SymKey* sym_key = PK11_ImportSymKey(slot.get(), cipher, PK11_OriginUnwrap, |
| CKA_ENCRYPT, &key_item, NULL); |
| if (!sym_key) |
| return NULL; |
| |
| return new SymmetricKey(sym_key); |
| } |
| |
| bool SymmetricKey::GetRawKey(std::string* raw_key) { |
| SECStatus rv = PK11_ExtractKeyValue(key_.get()); |
| if (SECSuccess != rv) |
| return false; |
| |
| SECItem* key_item = PK11_GetKeyData(key_.get()); |
| if (!key_item) |
| return false; |
| |
| raw_key->assign(reinterpret_cast<char*>(key_item->data), key_item->len); |
| return true; |
| } |
| |
| SymmetricKey::SymmetricKey(PK11SymKey* key) : key_(key) { |
| DCHECK(key); |
| } |
| |
| } // namespace crypto |