Botan  2.9.0
Crypto and TLS for C++11
pkcs8.cpp
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1 /*
2 * PKCS #8
3 * (C) 1999-2010,2014,2018 Jack Lloyd
4 *
5 * Botan is released under the Simplified BSD License (see license.txt)
6 */
7 
8 #include <botan/pkcs8.h>
9 #include <botan/rng.h>
10 #include <botan/der_enc.h>
11 #include <botan/ber_dec.h>
12 #include <botan/alg_id.h>
13 #include <botan/oids.h>
14 #include <botan/pem.h>
15 #include <botan/scan_name.h>
16 #include <botan/pk_algs.h>
17 
18 #if defined(BOTAN_HAS_PKCS5_PBES2)
19  #include <botan/pbes2.h>
20 #endif
21 
22 namespace Botan {
23 
24 namespace PKCS8 {
25 
26 namespace {
27 
28 /*
29 * Get info from an EncryptedPrivateKeyInfo
30 */
31 secure_vector<uint8_t> PKCS8_extract(DataSource& source,
32  AlgorithmIdentifier& pbe_alg_id)
33  {
34  secure_vector<uint8_t> key_data;
35 
36  BER_Decoder(source)
38  .decode(pbe_alg_id)
39  .decode(key_data, OCTET_STRING)
40  .verify_end();
41 
42  return key_data;
43  }
44 
45 /*
46 * PEM decode and/or decrypt a private key
47 */
48 secure_vector<uint8_t> PKCS8_decode(
49  DataSource& source,
50  std::function<std::string ()> get_passphrase,
51  AlgorithmIdentifier& pk_alg_id,
52  bool is_encrypted)
53  {
54  AlgorithmIdentifier pbe_alg_id;
55  secure_vector<uint8_t> key_data, key;
56 
57  try {
58  if(ASN1::maybe_BER(source) && !PEM_Code::matches(source))
59  {
60  if(is_encrypted)
61  {
62  key_data = PKCS8_extract(source, pbe_alg_id);
63  }
64  else
65  {
66  // todo read more efficiently
67  while(!source.end_of_data())
68  {
69  uint8_t b;
70  size_t read = source.read_byte(b);
71  if(read)
72  {
73  key_data.push_back(b);
74  }
75  }
76  }
77  }
78  else
79  {
80  std::string label;
81  key_data = PEM_Code::decode(source, label);
82 
83  // todo remove autodetect for pem as well?
84  if(label == "PRIVATE KEY")
85  is_encrypted = false;
86  else if(label == "ENCRYPTED PRIVATE KEY")
87  {
88  DataSource_Memory key_source(key_data);
89  key_data = PKCS8_extract(key_source, pbe_alg_id);
90  }
91  else
92  throw PKCS8_Exception("Unknown PEM label " + label);
93  }
94 
95  if(key_data.empty())
96  throw PKCS8_Exception("No key data found");
97  }
98  catch(Decoding_Error& e)
99  {
100  throw Decoding_Error("PKCS #8 private key decoding", e);
101  }
102 
103  try
104  {
105  if(is_encrypted)
106  {
107  if(OIDS::lookup(pbe_alg_id.get_oid()) != "PBE-PKCS5v20")
108  throw PKCS8_Exception("Unknown PBE type " + pbe_alg_id.get_oid().as_string());
109 #if defined(BOTAN_HAS_PKCS5_PBES2)
110  key = pbes2_decrypt(key_data, get_passphrase(), pbe_alg_id.get_parameters());
111 #else
112  BOTAN_UNUSED(get_passphrase);
113  throw Decoding_Error("Private key is encrypted but PBES2 was disabled in build");
114 #endif
115  }
116  else
117  key = key_data;
118 
119  BER_Decoder(key)
121  .decode_and_check<size_t>(0, "Unknown PKCS #8 version number")
122  .decode(pk_alg_id)
123  .decode(key, OCTET_STRING)
124  .discard_remaining()
125  .end_cons();
126  }
127  catch(std::exception& e)
128  {
129  throw Decoding_Error("PKCS #8 private key decoding", e);
130  }
131  return key;
132  }
133 
134 }
135 
136 /*
137 * BER encode a PKCS #8 private key, unencrypted
138 */
140  {
141  // keeping around for compat
142  return key.private_key_info();
143  }
144 
145 /*
146 * PEM encode a PKCS #8 private key, unencrypted
147 */
148 std::string PEM_encode(const Private_Key& key)
149  {
150  return PEM_Code::encode(PKCS8::BER_encode(key), "PRIVATE KEY");
151  }
152 
153 #if defined(BOTAN_HAS_PKCS5_PBES2)
154 
155 namespace {
156 
157 std::pair<std::string, std::string>
158 choose_pbe_params(const std::string& pbe_algo, const std::string& key_algo)
159  {
160  if(pbe_algo.empty())
161  {
162  // Defaults:
163  if(key_algo == "Curve25519" || key_algo == "McEliece")
164  return std::make_pair("AES-256/GCM", "SHA-512");
165  else // for everything else (RSA, DSA, ECDSA, GOST, ...)
166  return std::make_pair("AES-256/CBC", "SHA-256");
167  }
168 
169  SCAN_Name request(pbe_algo);
170 
171  if(request.arg_count() != 2 ||
172  (request.algo_name() != "PBE-PKCS5v20" && request.algo_name() != "PBES2"))
173  {
174  throw Invalid_Argument("Unsupported PBE " + pbe_algo);
175  }
176 
177  return std::make_pair(request.arg(0), request.arg(1));
178  }
179 
180 }
181 
182 #endif
183 
184 /*
185 * BER encode a PKCS #8 private key, encrypted
186 */
187 std::vector<uint8_t> BER_encode(const Private_Key& key,
189  const std::string& pass,
190  std::chrono::milliseconds msec,
191  const std::string& pbe_algo)
192  {
193 #if defined(BOTAN_HAS_PKCS5_PBES2)
194  const auto pbe_params = choose_pbe_params(pbe_algo, key.algo_name());
195 
196  const std::pair<AlgorithmIdentifier, std::vector<uint8_t>> pbe_info =
197  pbes2_encrypt_msec(PKCS8::BER_encode(key), pass, msec, nullptr,
198  pbe_params.first, pbe_params.second, rng);
199 
200  std::vector<uint8_t> output;
201  DER_Encoder der(output);
202  der.start_cons(SEQUENCE)
203  .encode(pbe_info.first)
204  .encode(pbe_info.second, OCTET_STRING)
205  .end_cons();
206 
207  return output;
208 #else
209  BOTAN_UNUSED(key, rng, pass, msec, pbe_algo);
210  throw Encoding_Error("PKCS8::BER_encode cannot encrypt because PBES2 was disabled in build");
211 #endif
212  }
213 
214 /*
215 * PEM encode a PKCS #8 private key, encrypted
216 */
217 std::string PEM_encode(const Private_Key& key,
219  const std::string& pass,
220  std::chrono::milliseconds msec,
221  const std::string& pbe_algo)
222  {
223  if(pass.empty())
224  return PEM_encode(key);
225 
226  return PEM_Code::encode(PKCS8::BER_encode(key, rng, pass, msec, pbe_algo),
227  "ENCRYPTED PRIVATE KEY");
228  }
229 
230 /*
231 * BER encode a PKCS #8 private key, encrypted
232 */
233 std::vector<uint8_t> BER_encode_encrypted_pbkdf_iter(const Private_Key& key,
235  const std::string& pass,
236  size_t pbkdf_iterations,
237  const std::string& cipher,
238  const std::string& pbkdf_hash)
239  {
240 #if defined(BOTAN_HAS_PKCS5_PBES2)
241  const std::pair<AlgorithmIdentifier, std::vector<uint8_t>> pbe_info =
243  pass, pbkdf_iterations,
244  cipher.empty() ? "AES-256/CBC" : cipher,
245  pbkdf_hash.empty() ? "SHA-256" : pbkdf_hash,
246  rng);
247 
248  std::vector<uint8_t> output;
249  DER_Encoder der(output);
250  der.start_cons(SEQUENCE)
251  .encode(pbe_info.first)
252  .encode(pbe_info.second, OCTET_STRING)
253  .end_cons();
254 
255  return output;
256 
257 #else
258  BOTAN_UNUSED(key, rng, pass, pbkdf_iterations, cipher, pbkdf_hash);
259  throw Encoding_Error("PKCS8::BER_encode_encrypted_pbkdf_iter cannot encrypt because PBES2 disabled in build");
260 #endif
261  }
262 
263 /*
264 * PEM encode a PKCS #8 private key, encrypted
265 */
268  const std::string& pass,
269  size_t pbkdf_iterations,
270  const std::string& cipher,
271  const std::string& pbkdf_hash)
272  {
273  return PEM_Code::encode(
274  PKCS8::BER_encode_encrypted_pbkdf_iter(key, rng, pass, pbkdf_iterations, cipher, pbkdf_hash),
275  "ENCRYPTED PRIVATE KEY");
276  }
277 
278 /*
279 * BER encode a PKCS #8 private key, encrypted
280 */
281 std::vector<uint8_t> BER_encode_encrypted_pbkdf_msec(const Private_Key& key,
283  const std::string& pass,
284  std::chrono::milliseconds pbkdf_msec,
285  size_t* pbkdf_iterations,
286  const std::string& cipher,
287  const std::string& pbkdf_hash)
288  {
289 #if defined(BOTAN_HAS_PKCS5_PBES2)
290  const std::pair<AlgorithmIdentifier, std::vector<uint8_t>> pbe_info =
292  pbkdf_msec, pbkdf_iterations,
293  cipher.empty() ? "AES-256/CBC" : cipher,
294  pbkdf_hash.empty() ? "SHA-256" : pbkdf_hash,
295  rng);
296 
297  std::vector<uint8_t> output;
298  DER_Encoder(output)
300  .encode(pbe_info.first)
301  .encode(pbe_info.second, OCTET_STRING)
302  .end_cons();
303 
304  return output;
305 #else
306  BOTAN_UNUSED(key, rng, pass, pbkdf_msec, pbkdf_iterations, cipher, pbkdf_hash);
307  throw Encoding_Error("BER_encode_encrypted_pbkdf_msec cannot encrypt because PBES2 disabled in build");
308 #endif
309  }
310 
311 /*
312 * PEM encode a PKCS #8 private key, encrypted
313 */
316  const std::string& pass,
317  std::chrono::milliseconds pbkdf_msec,
318  size_t* pbkdf_iterations,
319  const std::string& cipher,
320  const std::string& pbkdf_hash)
321  {
322  return PEM_Code::encode(
323  PKCS8::BER_encode_encrypted_pbkdf_msec(key, rng, pass, pbkdf_msec, pbkdf_iterations, cipher, pbkdf_hash),
324  "ENCRYPTED PRIVATE KEY");
325  }
326 
327 namespace {
328 
329 /*
330 * Extract a private key (encrypted/unencrypted) and return it
331 */
332 std::unique_ptr<Private_Key>
333 load_key(DataSource& source,
334  std::function<std::string ()> get_pass,
335  bool is_encrypted)
336  {
337  AlgorithmIdentifier alg_id;
338  secure_vector<uint8_t> pkcs8_key = PKCS8_decode(source, get_pass, alg_id, is_encrypted);
339 
340  const std::string alg_name = OIDS::lookup(alg_id.get_oid());
341  if(alg_name.empty() || alg_name == alg_id.get_oid().as_string())
342  throw PKCS8_Exception("Unknown algorithm OID: " +
343  alg_id.get_oid().as_string());
344 
345  return load_private_key(alg_id, pkcs8_key);
346  }
347 
348 }
349 
350 /*
351 * Extract an encrypted private key and return it
352 */
353 std::unique_ptr<Private_Key> load_key(DataSource& source,
354  std::function<std::string ()> get_pass)
355  {
356  return load_key(source, get_pass, true);
357  }
358 
359 /*
360 * Extract an encrypted private key and return it
361 */
362 std::unique_ptr<Private_Key> load_key(DataSource& source,
363  const std::string& pass)
364  {
365  return load_key(source, [pass]() { return pass; }, true);
366  }
367 
368 /*
369 * Extract an unencrypted private key and return it
370 */
371 std::unique_ptr<Private_Key> load_key(DataSource& source)
372  {
373  auto fail_fn = []() -> std::string {
374  throw PKCS8_Exception("Internal error: Attempt to read password for unencrypted key");
375  };
376 
377  return load_key(source, fail_fn, false);
378  }
379 
380 /*
381 * Make a copy of this private key
382 */
383 std::unique_ptr<Private_Key> copy_key(const Private_Key& key)
384  {
385  DataSource_Memory source(PEM_encode(key));
386  return PKCS8::load_key(source);
387  }
388 
389 /*
390 * Extract an encrypted private key and return it
391 */
394  std::function<std::string ()> get_pass)
395  {
396  BOTAN_UNUSED(rng);
397  return PKCS8::load_key(source, get_pass).release();
398  }
399 
400 /*
401 * Extract an encrypted private key and return it
402 */
405  const std::string& pass)
406  {
407  BOTAN_UNUSED(rng);
408  return PKCS8::load_key(source, pass).release();
409  }
410 
411 /*
412 * Extract an unencrypted private key and return it
413 */
416  {
417  BOTAN_UNUSED(rng);
418  return PKCS8::load_key(source).release();
419  }
420 
421 #if defined(BOTAN_TARGET_OS_HAS_FILESYSTEM)
422 
423 /*
424 * Extract an encrypted private key and return it
425 */
426 Private_Key* load_key(const std::string& fsname,
428  std::function<std::string ()> get_pass)
429  {
430  BOTAN_UNUSED(rng);
431  DataSource_Stream in(fsname);
432  return PKCS8::load_key(in, get_pass).release();
433  }
434 
435 /*
436 * Extract an encrypted private key and return it
437 */
438 Private_Key* load_key(const std::string& fsname,
439  RandomNumberGenerator& rng,
440  const std::string& pass)
441  {
442  BOTAN_UNUSED(rng);
443  DataSource_Stream in(fsname);
444  return PKCS8::load_key(in, [pass]() { return pass; }).release();
445  }
446 
447 /*
448 * Extract an unencrypted private key and return it
449 */
450 Private_Key* load_key(const std::string& fsname,
451  RandomNumberGenerator& rng)
452  {
453  BOTAN_UNUSED(rng);
454  DataSource_Stream in(fsname);
455  return PKCS8::load_key(in).release();
456  }
457 #endif
458 
459 /*
460 * Make a copy of this private key
461 */
464  {
465  BOTAN_UNUSED(rng);
466  return PKCS8::copy_key(key).release();
467  }
468 
469 
470 
471 }
472 
473 }
std::unique_ptr< Private_Key > load_private_key(const AlgorithmIdentifier &alg_id, const secure_vector< uint8_t > &key_bits)
Definition: pk_algs.cpp:167
std::unique_ptr< Private_Key > copy_key(const Private_Key &key)
Definition: pkcs8.cpp:383
BER_Decoder & decode_and_check(const T &expected, const std::string &error_msg)
Definition: ber_dec.h:277
std::string as_string() const
Definition: asn1_oid.h:48
std::pair< AlgorithmIdentifier, std::vector< uint8_t > > pbes2_encrypt_msec(const secure_vector< uint8_t > &key_bits, const std::string &passphrase, std::chrono::milliseconds msec, size_t *out_iterations_if_nonnull, const std::string &cipher, const std::string &digest, RandomNumberGenerator &rng)
Definition: pbes2.cpp:276
virtual std::string algo_name() const =0
std::vector< uint8_t > BER_encode_encrypted_pbkdf_iter(const Private_Key &key, RandomNumberGenerator &rng, const std::string &pass, size_t pbkdf_iterations, const std::string &cipher, const std::string &pbkdf_hash)
Definition: pkcs8.cpp:233
bool maybe_BER(DataSource &source)
Definition: asn1_obj.cpp:219
DER_Encoder & end_cons()
Definition: der_enc.cpp:191
std::vector< uint8_t > BER_encode_encrypted_pbkdf_msec(const Private_Key &key, RandomNumberGenerator &rng, const std::string &pass, std::chrono::milliseconds pbkdf_msec, size_t *pbkdf_iterations, const std::string &cipher, const std::string &pbkdf_hash)
Definition: pkcs8.cpp:281
BER_Decoder & decode(bool &out)
Definition: ber_dec.h:170
DER_Encoder & encode(bool b)
Definition: der_enc.cpp:285
secure_vector< uint8_t > private_key_info() const
Definition: pk_keys.cpp:64
std::string encode(const uint8_t der[], size_t length, const std::string &label, size_t width)
Definition: pem.cpp:43
bool matches(DataSource &source, const std::string &extra, size_t search_range)
Definition: pem.cpp:142
virtual bool end_of_data() const =0
std::pair< AlgorithmIdentifier, std::vector< uint8_t > > pbes2_encrypt_iter(const secure_vector< uint8_t > &key_bits, const std::string &passphrase, size_t pbkdf_iter, const std::string &cipher, const std::string &digest, RandomNumberGenerator &rng)
Definition: pbes2.cpp:295
std::string PEM_encode(const Private_Key &key)
Definition: pkcs8.cpp:148
secure_vector< uint8_t > decode(DataSource &source, std::string &label)
Definition: pem.cpp:68
BER_Decoder start_cons(ASN1_Tag type_tag, ASN1_Tag class_tag=UNIVERSAL)
Definition: ber_dec.cpp:290
Definition: alg_id.cpp:13
size_t read_byte(uint8_t &out)
Definition: data_src.cpp:23
secure_vector< uint8_t > BER_encode(const Private_Key &key)
Definition: pkcs8.cpp:139
secure_vector< uint8_t > pbes2_decrypt(const secure_vector< uint8_t > &key_bits, const std::string &passphrase, const std::vector< uint8_t > &params)
Definition: pbes2.cpp:306
#define BOTAN_UNUSED(...)
Definition: assert.h:142
std::string PEM_encode_encrypted_pbkdf_iter(const Private_Key &key, RandomNumberGenerator &rng, const std::string &pass, size_t pbkdf_iterations, const std::string &cipher, const std::string &pbkdf_hash)
Definition: pkcs8.cpp:266
const std::vector< uint8_t > & get_parameters() const
Definition: alg_id.h:38
const OID & get_oid() const
Definition: alg_id.h:37
BER_Decoder & verify_end()
Definition: ber_dec.cpp:208
DER_Encoder & start_cons(ASN1_Tag type_tag, ASN1_Tag class_tag=UNIVERSAL)
Definition: der_enc.cpp:181
std::vector< T, secure_allocator< T > > secure_vector
Definition: secmem.h:65
std::unique_ptr< Private_Key > load_key(DataSource &source, std::function< std::string()> get_pass)
Definition: pkcs8.cpp:353
std::string lookup(const OID &oid)
Definition: oids.cpp:113
std::string PEM_encode_encrypted_pbkdf_msec(const Private_Key &key, RandomNumberGenerator &rng, const std::string &pass, std::chrono::milliseconds pbkdf_msec, size_t *pbkdf_iterations, const std::string &cipher, const std::string &pbkdf_hash)
Definition: pkcs8.cpp:314