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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_EC_PRIVATE_KEY_H_
      6 #define CRYPTO_EC_PRIVATE_KEY_H_
      7 
      8 #include <stddef.h>
      9 #include <stdint.h>
     10 
     11 #include <string>
     12 #include <vector>
     13 
     14 #include "base/macros.h"
     15 #include "build/build_config.h"
     16 #include "crypto/crypto_export.h"
     17 
     18 #if defined(USE_OPENSSL)
     19 // Forward declaration for openssl/*.h
     20 typedef struct evp_pkey_st EVP_PKEY;
     21 #else
     22 // Forward declaration.
     23 typedef struct CERTSubjectPublicKeyInfoStr CERTSubjectPublicKeyInfo;
     24 typedef struct PK11SlotInfoStr PK11SlotInfo;
     25 typedef struct SECKEYPrivateKeyStr SECKEYPrivateKey;
     26 typedef struct SECKEYPublicKeyStr SECKEYPublicKey;
     27 #endif
     28 
     29 namespace crypto {
     30 
     31 // Encapsulates an elliptic curve (EC) private key. Can be used to generate new
     32 // keys, export keys to other formats, or to extract a public key.
     33 // TODO(mattm): make this and RSAPrivateKey implement some PrivateKey interface.
     34 // (The difference in types of key() and public_key() make this a little
     35 // tricky.)
     36 class CRYPTO_EXPORT ECPrivateKey {
     37  public:
     38   ~ECPrivateKey();
     39 
     40   // Creates a new random instance. Can return NULL if initialization fails.
     41   // The created key will use the NIST P-256 curve.
     42   // TODO(mattm): Add a curve parameter.
     43   static ECPrivateKey* Create();
     44 
     45   // Creates a new instance by importing an existing key pair.
     46   // The key pair is given as an ASN.1-encoded PKCS #8 EncryptedPrivateKeyInfo
     47   // block and an X.509 SubjectPublicKeyInfo block.
     48   // Returns NULL if initialization fails.
     49   static ECPrivateKey* CreateFromEncryptedPrivateKeyInfo(
     50       const std::string& password,
     51       const std::vector<uint8_t>& encrypted_private_key_info,
     52       const std::vector<uint8_t>& subject_public_key_info);
     53 
     54 #if !defined(USE_OPENSSL)
     55   // Imports the key pair into |slot| and returns in |public_key| and |key|.
     56   // Shortcut for code that needs to keep a reference directly to NSS types
     57   // without having to create a ECPrivateKey object and make a copy of them.
     58   // TODO(mattm): move this function to some NSS util file.
     59   static bool ImportFromEncryptedPrivateKeyInfo(
     60       PK11SlotInfo* slot,
     61       const std::string& password,
     62       const uint8_t* encrypted_private_key_info,
     63       size_t encrypted_private_key_info_len,
     64       CERTSubjectPublicKeyInfo* decoded_spki,
     65       bool permanent,
     66       bool sensitive,
     67       SECKEYPrivateKey** key,
     68       SECKEYPublicKey** public_key);
     69 #endif
     70 
     71   // Returns a copy of the object.
     72   ECPrivateKey* Copy() const;
     73 
     74 #if defined(USE_OPENSSL)
     75   EVP_PKEY* key() { return key_; }
     76 #else
     77   SECKEYPrivateKey* key() { return key_; }
     78   SECKEYPublicKey* public_key() { return public_key_; }
     79 #endif
     80 
     81   // Exports the private key as an ASN.1-encoded PKCS #8 EncryptedPrivateKeyInfo
     82   // block and the public key as an X.509 SubjectPublicKeyInfo block.
     83   // The |password| and |iterations| are used as inputs to the key derivation
     84   // function for generating the encryption key.  PKCS #5 recommends a minimum
     85   // of 1000 iterations, on modern systems a larger value may be preferrable.
     86   bool ExportEncryptedPrivateKey(const std::string& password,
     87                                  int iterations,
     88                                  std::vector<uint8_t>* output);
     89 
     90   // Exports the public key to an X.509 SubjectPublicKeyInfo block.
     91   bool ExportPublicKey(std::vector<uint8_t>* output);
     92 
     93   // Exports the public key as an EC point in the uncompressed point format.
     94   bool ExportRawPublicKey(std::string* output);
     95 
     96   // Exports private key data for testing. The format of data stored into output
     97   // doesn't matter other than that it is consistent for the same key.
     98   bool ExportValue(std::vector<uint8_t>* output);
     99   bool ExportECParams(std::vector<uint8_t>* output);
    100 
    101  private:
    102   // Constructor is private. Use one of the Create*() methods above instead.
    103   ECPrivateKey();
    104 
    105 #if defined(USE_OPENSSL)
    106   EVP_PKEY* key_;
    107 #else
    108   SECKEYPrivateKey* key_;
    109   SECKEYPublicKey* public_key_;
    110 #endif
    111 
    112   DISALLOW_COPY_AND_ASSIGN(ECPrivateKey);
    113 };
    114 
    115 
    116 }  // namespace crypto
    117 
    118 #endif  // CRYPTO_EC_PRIVATE_KEY_H_
    119