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| 1 // Copyright (c) 2012 The Chromium Authors. All rights reserved. | |
| 2 // Use of this source code is governed by a BSD-style license that can be | |
| 3 // found in the LICENSE file. | |
| 4 | |
| 5 #ifndef CRYPTO_ENCRYPTOR_H_ | |
| 6 #define CRYPTO_ENCRYPTOR_H_ | |
| 7 | |
| 8 #include <string> | |
| 9 | |
| 10 #include "base/basictypes.h" | |
| 11 #include "base/memory/scoped_ptr.h" | |
| 12 #include "base/strings/string_piece.h" | |
| 13 #include "build/build_config.h" | |
| 14 #include "crypto/crypto_export.h" | |
| 15 | |
| 16 #if defined(USE_NSS) || \ | |
| 17 (!defined(USE_OPENSSL) && (defined(OS_WIN) || defined(OS_MACOSX))) | |
| 18 #include "crypto/scoped_nss_types.h" | |
| 19 #endif | |
| 20 | |
| 21 namespace crypto { | |
| 22 | |
| 23 class SymmetricKey; | |
| 24 | |
| 25 class CRYPTO_EXPORT Encryptor { | |
| 26 public: | |
| 27 enum Mode { | |
| 28 CBC, | |
| 29 CTR, | |
| 30 }; | |
| 31 | |
| 32 // This class implements a 128-bits counter to be used in AES-CTR encryption. | |
| 33 // Only 128-bits counter is supported in this class. | |
| 34 class CRYPTO_EXPORT Counter { | |
| 35 public: | |
| 36 explicit Counter(const base::StringPiece& counter); | |
| 37 ~Counter(); | |
| 38 | |
| 39 // Increment the counter value. | |
| 40 bool Increment(); | |
| 41 | |
| 42 // Write the content of the counter to |buf|. |buf| should have enough | |
| 43 // space for |GetLengthInBytes()|. | |
| 44 void Write(void* buf); | |
| 45 | |
| 46 // Return the length of this counter. | |
| 47 size_t GetLengthInBytes() const; | |
| 48 | |
| 49 private: | |
| 50 union { | |
| 51 uint32 components32[4]; | |
| 52 uint64 components64[2]; | |
| 53 } counter_; | |
| 54 }; | |
| 55 | |
| 56 Encryptor(); | |
| 57 virtual ~Encryptor(); | |
| 58 | |
| 59 // Initializes the encryptor using |key| and |iv|. Returns false if either the | |
| 60 // key or the initialization vector cannot be used. | |
| 61 // | |
| 62 // If |mode| is CBC, |iv| must not be empty; if it is CTR, then |iv| must be | |
| 63 // empty. | |
| 64 bool Init(SymmetricKey* key, Mode mode, const base::StringPiece& iv); | |
| 65 | |
| 66 // Encrypts |plaintext| into |ciphertext|. |plaintext| may only be empty if | |
| 67 // the mode is CBC. | |
| 68 bool Encrypt(const base::StringPiece& plaintext, std::string* ciphertext); | |
| 69 | |
| 70 // Decrypts |ciphertext| into |plaintext|. |ciphertext| must not be empty. | |
| 71 // | |
| 72 // WARNING: In CBC mode, Decrypt() returns false if it detects the padding | |
| 73 // in the decrypted plaintext is wrong. Padding errors can result from | |
| 74 // tampered ciphertext or a wrong decryption key. But successful decryption | |
| 75 // does not imply the authenticity of the data. The caller of Decrypt() | |
| 76 // must either authenticate the ciphertext before decrypting it, or take | |
| 77 // care to not report decryption failure. Otherwise it could inadvertently | |
| 78 // be used as a padding oracle to attack the cryptosystem. | |
| 79 bool Decrypt(const base::StringPiece& ciphertext, std::string* plaintext); | |
| 80 | |
| 81 // Sets the counter value when in CTR mode. Currently only 128-bits | |
| 82 // counter value is supported. | |
| 83 // | |
| 84 // Returns true only if update was successful. | |
| 85 bool SetCounter(const base::StringPiece& counter); | |
| 86 | |
| 87 // TODO(albertb): Support streaming encryption. | |
| 88 | |
| 89 private: | |
| 90 // Generates a mask using |counter_| to be used for encryption in CTR mode. | |
| 91 // Resulting mask will be written to |mask| with |mask_len| bytes. | |
| 92 // | |
| 93 // Make sure there's enough space in mask when calling this method. | |
| 94 // Reserve at least |plaintext_len| + 16 bytes for |mask|. | |
| 95 // | |
| 96 // The generated mask will always have at least |plaintext_len| bytes and | |
| 97 // will be a multiple of the counter length. | |
| 98 // | |
| 99 // This method is used only in CTR mode. | |
| 100 // | |
| 101 // Returns false if this call failed. | |
| 102 bool GenerateCounterMask(size_t plaintext_len, | |
| 103 uint8* mask, | |
| 104 size_t* mask_len); | |
| 105 | |
| 106 // Mask the |plaintext| message using |mask|. The output will be written to | |
| 107 // |ciphertext|. |ciphertext| must have at least |plaintext_len| bytes. | |
| 108 void MaskMessage(const void* plaintext, | |
| 109 size_t plaintext_len, | |
| 110 const void* mask, | |
| 111 void* ciphertext) const; | |
| 112 | |
| 113 SymmetricKey* key_; | |
| 114 Mode mode_; | |
| 115 scoped_ptr<Counter> counter_; | |
| 116 | |
| 117 #if defined(USE_OPENSSL) | |
| 118 bool Crypt(bool do_encrypt, // Pass true to encrypt, false to decrypt. | |
| 119 const base::StringPiece& input, | |
| 120 std::string* output); | |
| 121 bool CryptCTR(bool do_encrypt, | |
| 122 const base::StringPiece& input, | |
| 123 std::string* output); | |
| 124 std::string iv_; | |
| 125 #elif defined(USE_NSS) || defined(OS_WIN) || defined(OS_MACOSX) | |
| 126 bool Crypt(PK11Context* context, | |
| 127 const base::StringPiece& input, | |
| 128 std::string* output); | |
| 129 bool CryptCTR(PK11Context* context, | |
| 130 const base::StringPiece& input, | |
| 131 std::string* output); | |
| 132 ScopedSECItem param_; | |
| 133 #endif | |
| 134 }; | |
| 135 | |
| 136 } // namespace crypto | |
| 137 | |
| 138 #endif // CRYPTO_ENCRYPTOR_H_ | |
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Chromium Code Reviews
Issue 956613002:
Reland "Cut down /crypto and switch what is left of it to boringssl". (Closed)
Base URL: git@github.com:domokit/mojo.git@master