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1 // Copyright (c) 2009 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 BASE_CRYPTO_RSA_PRIVATE_KEY_H_
6 #define BASE_CRYPTO_RSA_PRIVATE_KEY_H_
7 
8 #include "build/build_config.h"
9 
10 #if defined(USE_NSS)
11 // Forward declaration.
12 struct SECKEYPrivateKeyStr;
13 struct SECKEYPublicKeyStr;
14 #elif defined(OS_MACOSX)
15 #include <Security/cssm.h>
16 #elif defined(OS_WIN)
17 #include <windows.h>
18 #include <wincrypt.h>
19 #endif
20 
21 #include <list>
22 #include <vector>
23 
24 #include "base/basictypes.h"
25 
26 namespace base {
27 
28 // Used internally by RSAPrivateKey for serializing and deserializing
29 // PKCS #8 PrivateKeyInfo and PublicKeyInfo.
30 class PrivateKeyInfoCodec {
31  public:
32 
33   // ASN.1 encoding of the AlgorithmIdentifier from PKCS #8.
34   static const uint8 kRsaAlgorithmIdentifier[];
35 
36   // ASN.1 tags for some types we use.
37   static const uint8 kBitStringTag = 0x03;
38   static const uint8 kIntegerTag = 0x02;
39   static const uint8 kNullTag = 0x05;
40   static const uint8 kOctetStringTag = 0x04;
41   static const uint8 kSequenceTag = 0x30;
42 
43   // |big_endian| here specifies the byte-significance of the integer components
44   // that will be parsed & serialized (modulus(), etc...) during Import(),
45   // Export() and ExportPublicKeyInfo() -- not the ASN.1 DER encoding of the
46   // PrivateKeyInfo/PublicKeyInfo (which is always big-endian).
PrivateKeyInfoCodec(bool big_endian)47   explicit PrivateKeyInfoCodec(bool big_endian) : big_endian_(big_endian) {}
48 
49   // Exports the contents of the integer components to the ASN.1 DER encoding
50   // of the PrivateKeyInfo structure to |output|.
51   bool Export(std::vector<uint8>* output);
52 
53   // Exports the contents of the integer components to the ASN.1 DER encoding
54   // of the PublicKeyInfo structure to |output|.
55   bool ExportPublicKeyInfo(std::vector<uint8>* output);
56 
57   // Parses the ASN.1 DER encoding of the PrivateKeyInfo structure in |input|
58   // and populates the integer components with |big_endian_| byte-significance.
59   // IMPORTANT NOTE: This is currently *not* security-approved for importing
60   // keys from unstrusted sources.
61   bool Import(const std::vector<uint8>& input);
62 
63   // Accessors to the contents of the integer components of the PrivateKeyInfo
64   // structure.
modulus()65   std::vector<uint8>* modulus() { return &modulus_; };
public_exponent()66   std::vector<uint8>* public_exponent() { return &public_exponent_; };
private_exponent()67   std::vector<uint8>* private_exponent() { return &private_exponent_; };
prime1()68   std::vector<uint8>* prime1() { return &prime1_; };
prime2()69   std::vector<uint8>* prime2() { return &prime2_; };
exponent1()70   std::vector<uint8>* exponent1() { return &exponent1_; };
exponent2()71   std::vector<uint8>* exponent2() { return &exponent2_; };
coefficient()72   std::vector<uint8>* coefficient() { return &coefficient_; };
73 
74  private:
75   // Utility wrappers for PrependIntegerImpl that use the class's |big_endian_|
76   // value.
77   void PrependInteger(const std::vector<uint8>& in, std::list<uint8>* out);
78   void PrependInteger(uint8* val, int num_bytes, std::list<uint8>* data);
79 
80   // Prepends the integer stored in |val| - |val + num_bytes| with |big_endian|
81   // byte-significance into |data| as an ASN.1 integer.
82   void PrependIntegerImpl(uint8* val,
83                           int num_bytes,
84                           std::list<uint8>* data,
85                           bool big_endian);
86 
87   // Utility wrappers for ReadIntegerImpl that use the class's |big_endian_|
88   // value.
89   bool ReadInteger(uint8** pos, uint8* end, std::vector<uint8>* out);
90   bool ReadIntegerWithExpectedSize(uint8** pos,
91                                    uint8* end,
92                                    size_t expected_size,
93                                    std::vector<uint8>* out);
94 
95   // Reads an ASN.1 integer from |pos|, and stores the result into |out| with
96   // |big_endian| byte-significance.
97   bool ReadIntegerImpl(uint8** pos,
98                        uint8* end,
99                        std::vector<uint8>* out,
100                        bool big_endian);
101 
102   // Prepends the integer stored in |val|, starting a index |start|, for
103   // |num_bytes| bytes onto |data|.
104   void PrependBytes(uint8* val,
105                     int start,
106                     int num_bytes,
107                     std::list<uint8>* data);
108 
109   // Helper to prepend an ASN.1 length field.
110   void PrependLength(size_t size, std::list<uint8>* data);
111 
112   // Helper to prepend an ASN.1 type header.
113   void PrependTypeHeaderAndLength(uint8 type,
114                                   uint32 length,
115                                   std::list<uint8>* output);
116 
117   // Helper to prepend an ASN.1 bit string
118   void PrependBitString(uint8* val, int num_bytes, std::list<uint8>* output);
119 
120   // Read an ASN.1 length field. This also checks that the length does not
121   // extend beyond |end|.
122   bool ReadLength(uint8** pos, uint8* end, uint32* result);
123 
124   // Read an ASN.1 type header and its length.
125   bool ReadTypeHeaderAndLength(uint8** pos,
126                                uint8* end,
127                                uint8 expected_tag,
128                                uint32* length);
129 
130   // Read an ASN.1 sequence declaration. This consumes the type header and
131   // length field, but not the contents of the sequence.
132   bool ReadSequence(uint8** pos, uint8* end);
133 
134   // Read the RSA AlgorithmIdentifier.
135   bool ReadAlgorithmIdentifier(uint8** pos, uint8* end);
136 
137   // Read one of the two version fields in PrivateKeyInfo.
138   bool ReadVersion(uint8** pos, uint8* end);
139 
140   // The byte-significance of the stored components (modulus, etc..).
141   bool big_endian_;
142 
143   // Component integers of the PrivateKeyInfo
144   std::vector<uint8> modulus_;
145   std::vector<uint8> public_exponent_;
146   std::vector<uint8> private_exponent_;
147   std::vector<uint8> prime1_;
148   std::vector<uint8> prime2_;
149   std::vector<uint8> exponent1_;
150   std::vector<uint8> exponent2_;
151   std::vector<uint8> coefficient_;
152 
153   DISALLOW_COPY_AND_ASSIGN(PrivateKeyInfoCodec);
154 };
155 
156 // Encapsulates an RSA private key. Can be used to generate new keys, export
157 // keys to other formats, or to extract a public key.
158 class RSAPrivateKey {
159  public:
160   // Create a new random instance. Can return NULL if initialization fails.
161   static RSAPrivateKey* Create(uint16 num_bits);
162 
163   // Create a new instance by importing an existing private key. The format is
164   // an ASN.1-encoded PrivateKeyInfo block from PKCS #8. This can return NULL if
165   // initialization fails.
166   static RSAPrivateKey* CreateFromPrivateKeyInfo(
167       const std::vector<uint8>& input);
168 
169   ~RSAPrivateKey();
170 
171 #if defined(USE_NSS)
key()172   SECKEYPrivateKeyStr* key() { return key_; }
173 #elif defined(OS_WIN)
provider()174   HCRYPTPROV provider() { return provider_; }
key()175   HCRYPTKEY key() { return key_; }
176 #elif defined(OS_MACOSX)
csp_handle()177   CSSM_CSP_HANDLE csp_handle() { return csp_handle_; }
key()178   CSSM_KEY_PTR key() { return &key_; }
179 #endif
180 
181   // Exports the private key to a PKCS #1 PrivateKey block.
182   bool ExportPrivateKey(std::vector<uint8>* output);
183 
184   // Exports the public key to an X509 SubjectPublicKeyInfo block.
185   bool ExportPublicKey(std::vector<uint8>* output);
186 
187 private:
188   // Constructor is private. Use Create() or CreateFromPrivateKeyInfo()
189   // instead.
190   RSAPrivateKey();
191 
192 #if defined(USE_NSS)
193   SECKEYPrivateKeyStr* key_;
194   SECKEYPublicKeyStr* public_key_;
195 #elif defined(OS_WIN)
196   bool InitProvider();
197 
198   HCRYPTPROV provider_;
199   HCRYPTKEY key_;
200 #elif defined(OS_MACOSX)
201   CSSM_KEY key_;
202   CSSM_CSP_HANDLE csp_handle_;
203 #endif
204 
205   DISALLOW_COPY_AND_ASSIGN(RSAPrivateKey);
206 };
207 
208 }  // namespace base
209 
210 #endif  // BASE_CRYPTO_RSA_PRIVATE_KEY_H_
211