crypto/rsa_private_key_win.cc

   1 // Copyright (c) 2011 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 #include "crypto/rsa_private_key.h"
   6
   7 #include <list>
   8
   9 #include "base/logging.h"
  10 #include "base/memory/scoped_ptr.h"
  11 #include "base/string_util.h"
  12
  13 #pragma comment(lib, "crypt32.lib")
  14
  15 namespace {
  16   // Helper for error handling during key import.
  17 #define READ_ASSERT(truth) \
  18   if (!(truth)) { \
  19   NOTREACHED(); \
  20   return false; \
  21   }
  22 }  // namespace
  23
  24 namespace crypto {
  25
  26 // static
  27 RSAPrivateKey* RSAPrivateKey::Create(uint16 num_bits) {
  28   scoped_ptr<RSAPrivateKey> result(new RSAPrivateKey);
  29   if (!result->InitProvider())
  30     return NULL;
  31
  32   DWORD flags = CRYPT_EXPORTABLE;
  33
  34   // The size is encoded as the upper 16 bits of the flags. :: sigh ::.
  35   flags |= (num_bits << 16);
  36   if (!CryptGenKey(result->provider_, CALG_RSA_SIGN, flags,
  37                    result->key_.receive()))
  38     return NULL;
  39
  40   return result.release();
  41 }
  42
  43 // static
  44 RSAPrivateKey* RSAPrivateKey::CreateSensitive(uint16 num_bits) {
  45   NOTIMPLEMENTED();
  46   return NULL;
  47 }
  48
  49 // static
  50 RSAPrivateKey* RSAPrivateKey::CreateFromPrivateKeyInfo(
  51     const std::vector<uint8>& input) {
  52   scoped_ptr<RSAPrivateKey> result(new RSAPrivateKey);
  53   if (!result->InitProvider())
  54     return NULL;
  55
  56   PrivateKeyInfoCodec pki(false);  // Little-Endian
  57   pki.Import(input);
  58
  59   int blob_size = sizeof(PUBLICKEYSTRUC) +
  60                   sizeof(RSAPUBKEY) +
  61                   pki.modulus()->size() +
  62                   pki.prime1()->size() +
  63                   pki.prime2()->size() +
  64                   pki.exponent1()->size() +
  65                   pki.exponent2()->size() +
  66                   pki.coefficient()->size() +
  67                   pki.private_exponent()->size();
  68   scoped_array<BYTE> blob(new BYTE[blob_size]);
  69
  70   uint8* dest = blob.get();
  71   PUBLICKEYSTRUC* public_key_struc = reinterpret_cast<PUBLICKEYSTRUC*>(dest);
  72   public_key_struc->bType = PRIVATEKEYBLOB;
  73   public_key_struc->bVersion = 0x02;
  74   public_key_struc->reserved = 0;
  75   public_key_struc->aiKeyAlg = CALG_RSA_SIGN;
  76   dest += sizeof(PUBLICKEYSTRUC);
  77
  78   RSAPUBKEY* rsa_pub_key = reinterpret_cast<RSAPUBKEY*>(dest);
  79   rsa_pub_key->magic = 0x32415352;
  80   rsa_pub_key->bitlen = pki.modulus()->size() * 8;
  81   int public_exponent_int = 0;
  82   for (size_t i = pki.public_exponent()->size(); i > 0; --i) {
  83     public_exponent_int <<= 8;
  84     public_exponent_int |= (*pki.public_exponent())[i - 1];
  85   }
  86   rsa_pub_key->pubexp = public_exponent_int;
  87   dest += sizeof(RSAPUBKEY);
  88
  89   memcpy(dest, &pki.modulus()->front(), pki.modulus()->size());
  90   dest += pki.modulus()->size();
  91   memcpy(dest, &pki.prime1()->front(), pki.prime1()->size());
  92   dest += pki.prime1()->size();
  93   memcpy(dest, &pki.prime2()->front(), pki.prime2()->size());
  94   dest += pki.prime2()->size();
  95   memcpy(dest, &pki.exponent1()->front(), pki.exponent1()->size());
  96   dest += pki.exponent1()->size();
  97   memcpy(dest, &pki.exponent2()->front(), pki.exponent2()->size());
  98   dest += pki.exponent2()->size();
  99   memcpy(dest, &pki.coefficient()->front(), pki.coefficient()->size());
 100   dest += pki.coefficient()->size();
 101   memcpy(dest, &pki.private_exponent()->front(),
 102          pki.private_exponent()->size());
 103   dest += pki.private_exponent()->size();
 104
 105   READ_ASSERT(dest == blob.get() + blob_size);
 106   if (!CryptImportKey(result->provider_,
 107                       reinterpret_cast<uint8*>(public_key_struc), blob_size, 0,
 108                       CRYPT_EXPORTABLE, result->key_.receive()))
 109     return NULL;
 110
 111   return result.release();
 112 }
 113
 114 // static
 115 RSAPrivateKey* RSAPrivateKey::CreateSensitiveFromPrivateKeyInfo(
 116     const std::vector<uint8>& input) {
 117   NOTIMPLEMENTED();
 118   return NULL;
 119 }
 120
 121 // static
 122 RSAPrivateKey* RSAPrivateKey::FindFromPublicKeyInfo(
 123     const std::vector<uint8>& input) {
 124   NOTIMPLEMENTED();
 125   return NULL;
 126 }
 127
 128 RSAPrivateKey::RSAPrivateKey() : provider_(NULL), key_(NULL) {}
 129
 130 RSAPrivateKey::~RSAPrivateKey() {}
 131
 132 bool RSAPrivateKey::InitProvider() {
 133   return FALSE != CryptAcquireContext(provider_.receive(), NULL, NULL,
 134                                       PROV_RSA_FULL, CRYPT_VERIFYCONTEXT);
 135 }
 136
 137 bool RSAPrivateKey::ExportPrivateKey(std::vector<uint8>* output) {
 138   // Export the key
 139   DWORD blob_length = 0;
 140   if (!CryptExportKey(key_, 0, PRIVATEKEYBLOB, 0, NULL, &blob_length)) {
 141     NOTREACHED();
 142     return false;
 143   }
 144
 145   scoped_array<uint8> blob(new uint8[blob_length]);
 146   if (!CryptExportKey(key_, 0, PRIVATEKEYBLOB, 0, blob.get(), &blob_length)) {
 147     NOTREACHED();
 148     return false;
 149   }
 150
 151   uint8* pos = blob.get();
 152   PUBLICKEYSTRUC *publickey_struct = reinterpret_cast<PUBLICKEYSTRUC*>(pos);
 153   pos += sizeof(PUBLICKEYSTRUC);
 154
 155   RSAPUBKEY *rsa_pub_key = reinterpret_cast<RSAPUBKEY*>(pos);
 156   pos += sizeof(RSAPUBKEY);
 157
 158   int mod_size = rsa_pub_key->bitlen / 8;
 159   int primes_size = rsa_pub_key->bitlen / 16;
 160
 161   PrivateKeyInfoCodec pki(false);  // Little-Endian
 162
 163   pki.modulus()->assign(pos, pos + mod_size);
 164   pos += mod_size;
 165
 166   pki.prime1()->assign(pos, pos + primes_size);
 167   pos += primes_size;
 168   pki.prime2()->assign(pos, pos + primes_size);
 169   pos += primes_size;
 170
 171   pki.exponent1()->assign(pos, pos + primes_size);
 172   pos += primes_size;
 173   pki.exponent2()->assign(pos, pos + primes_size);
 174   pos += primes_size;
 175
 176   pki.coefficient()->assign(pos, pos + primes_size);
 177   pos += primes_size;
 178
 179   pki.private_exponent()->assign(pos, pos + mod_size);
 180   pos += mod_size;
 181
 182   pki.public_exponent()->assign(reinterpret_cast<uint8*>(&rsa_pub_key->pubexp),
 183       reinterpret_cast<uint8*>(&rsa_pub_key->pubexp) + 4);
 184
 185   CHECK_EQ(pos - blob_length, reinterpret_cast<BYTE*>(publickey_struct));
 186
 187   return pki.Export(output);
 188 }
 189
 190 bool RSAPrivateKey::ExportPublicKey(std::vector<uint8>* output) {
 191   DWORD key_info_len;
 192   if (!CryptExportPublicKeyInfo(
 193       provider_, AT_SIGNATURE, X509_ASN_ENCODING | PKCS_7_ASN_ENCODING,
 194       NULL, &key_info_len)) {
 195     NOTREACHED();
 196     return false;
 197   }
 198
 199   scoped_array<uint8> key_info(new uint8[key_info_len]);
 200   if (!CryptExportPublicKeyInfo(
 201       provider_, AT_SIGNATURE, X509_ASN_ENCODING | PKCS_7_ASN_ENCODING,
 202       reinterpret_cast<CERT_PUBLIC_KEY_INFO*>(key_info.get()), &key_info_len)) {
 203     NOTREACHED();
 204     return false;
 205   }
 206
 207   DWORD encoded_length;
 208   if (!CryptEncodeObject(
 209       X509_ASN_ENCODING | PKCS_7_ASN_ENCODING, X509_PUBLIC_KEY_INFO,
 210       reinterpret_cast<CERT_PUBLIC_KEY_INFO*>(key_info.get()), NULL,
 211       &encoded_length)) {
 212     NOTREACHED();
 213     return false;
 214   }
 215
 216   scoped_array<BYTE> encoded(new BYTE[encoded_length]);
 217   if (!CryptEncodeObject(
 218       X509_ASN_ENCODING | PKCS_7_ASN_ENCODING, X509_PUBLIC_KEY_INFO,
 219       reinterpret_cast<CERT_PUBLIC_KEY_INFO*>(key_info.get()), encoded.get(),
 220       &encoded_length)) {
 221     NOTREACHED();
 222     return false;
 223   }
 224
 225   for (size_t i = 0; i < encoded_length; ++i)
 226     output->push_back(encoded[i]);
 227
 228   return true;
 229 }
 230
 231 }  // namespace crypto