Botan  2.8.0
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 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  if(request.arg_count() != 2)
171  throw Exception("Unsupported PBE " + pbe_algo);
172  if(request.algo_name() != "PBE-PKCS5v20" && request.algo_name() != "PBES2")
173  throw Exception("Unsupported PBE " + pbe_algo);
174  return std::make_pair(request.arg(0), request.arg(1));
175  }
176 
177 }
178 
179 #endif
180 
181 /*
182 * BER encode a PKCS #8 private key, encrypted
183 */
184 std::vector<uint8_t> BER_encode(const Private_Key& key,
186  const std::string& pass,
187  std::chrono::milliseconds msec,
188  const std::string& pbe_algo)
189  {
190 #if defined(BOTAN_HAS_PKCS5_PBES2)
191  const auto pbe_params = choose_pbe_params(pbe_algo, key.algo_name());
192 
193  const std::pair<AlgorithmIdentifier, std::vector<uint8_t>> pbe_info =
194  pbes2_encrypt_msec(PKCS8::BER_encode(key), pass, msec, nullptr,
195  pbe_params.first, pbe_params.second, rng);
196 
197  std::vector<uint8_t> output;
198  DER_Encoder der(output);
199  der.start_cons(SEQUENCE)
200  .encode(pbe_info.first)
201  .encode(pbe_info.second, OCTET_STRING)
202  .end_cons();
203 
204  return output;
205 #else
206  BOTAN_UNUSED(key, rng, pass, msec, pbe_algo);
207  throw Encoding_Error("PKCS8::BER_encode cannot encrypt because PBES2 was disabled in build");
208 #endif
209  }
210 
211 /*
212 * PEM encode a PKCS #8 private key, encrypted
213 */
214 std::string PEM_encode(const Private_Key& key,
216  const std::string& pass,
217  std::chrono::milliseconds msec,
218  const std::string& pbe_algo)
219  {
220  if(pass.empty())
221  return PEM_encode(key);
222 
223  return PEM_Code::encode(PKCS8::BER_encode(key, rng, pass, msec, pbe_algo),
224  "ENCRYPTED PRIVATE KEY");
225  }
226 
227 /*
228 * BER encode a PKCS #8 private key, encrypted
229 */
230 std::vector<uint8_t> BER_encode_encrypted_pbkdf_iter(const Private_Key& key,
232  const std::string& pass,
233  size_t pbkdf_iterations,
234  const std::string& cipher,
235  const std::string& pbkdf_hash)
236  {
237 #if defined(BOTAN_HAS_PKCS5_PBES2)
238  const std::pair<AlgorithmIdentifier, std::vector<uint8_t>> pbe_info =
240  pass, pbkdf_iterations,
241  cipher.empty() ? "AES-256/CBC" : cipher,
242  pbkdf_hash.empty() ? "SHA-256" : pbkdf_hash,
243  rng);
244 
245  std::vector<uint8_t> output;
246  DER_Encoder der(output);
247  der.start_cons(SEQUENCE)
248  .encode(pbe_info.first)
249  .encode(pbe_info.second, OCTET_STRING)
250  .end_cons();
251 
252  return output;
253 
254 #else
255  BOTAN_UNUSED(key, rng, pass, pbkdf_iterations, cipher, pbkdf_hash);
256  throw Encoding_Error("PKCS8::BER_encode_encrypted_pbkdf_iter cannot encrypt because PBES2 disabled in build");
257 #endif
258  }
259 
260 /*
261 * PEM encode a PKCS #8 private key, encrypted
262 */
265  const std::string& pass,
266  size_t pbkdf_iterations,
267  const std::string& cipher,
268  const std::string& pbkdf_hash)
269  {
270  return PEM_Code::encode(
271  PKCS8::BER_encode_encrypted_pbkdf_iter(key, rng, pass, pbkdf_iterations, cipher, pbkdf_hash),
272  "ENCRYPTED PRIVATE KEY");
273  }
274 
275 /*
276 * BER encode a PKCS #8 private key, encrypted
277 */
278 std::vector<uint8_t> BER_encode_encrypted_pbkdf_msec(const Private_Key& key,
280  const std::string& pass,
281  std::chrono::milliseconds pbkdf_msec,
282  size_t* pbkdf_iterations,
283  const std::string& cipher,
284  const std::string& pbkdf_hash)
285  {
286 #if defined(BOTAN_HAS_PKCS5_PBES2)
287  const std::pair<AlgorithmIdentifier, std::vector<uint8_t>> pbe_info =
289  pbkdf_msec, pbkdf_iterations,
290  cipher.empty() ? "AES-256/CBC" : cipher,
291  pbkdf_hash.empty() ? "SHA-256" : pbkdf_hash,
292  rng);
293 
294  std::vector<uint8_t> output;
295  DER_Encoder(output)
297  .encode(pbe_info.first)
298  .encode(pbe_info.second, OCTET_STRING)
299  .end_cons();
300 
301  return output;
302 #else
303  BOTAN_UNUSED(key, rng, pass, pbkdf_msec, pbkdf_iterations, cipher, pbkdf_hash);
304  throw Encoding_Error("BER_encode_encrypted_pbkdf_msec cannot encrypt because PBES2 disabled in build");
305 #endif
306  }
307 
308 /*
309 * PEM encode a PKCS #8 private key, encrypted
310 */
313  const std::string& pass,
314  std::chrono::milliseconds pbkdf_msec,
315  size_t* pbkdf_iterations,
316  const std::string& cipher,
317  const std::string& pbkdf_hash)
318  {
319  return PEM_Code::encode(
320  PKCS8::BER_encode_encrypted_pbkdf_msec(key, rng, pass, pbkdf_msec, pbkdf_iterations, cipher, pbkdf_hash),
321  "ENCRYPTED PRIVATE KEY");
322  }
323 
324 namespace {
325 
326 /*
327 * Extract a private key (encrypted/unencrypted) and return it
328 */
329 std::unique_ptr<Private_Key>
330 load_key(DataSource& source,
331  std::function<std::string ()> get_pass,
332  bool is_encrypted)
333  {
334  AlgorithmIdentifier alg_id;
335  secure_vector<uint8_t> pkcs8_key = PKCS8_decode(source, get_pass, alg_id, is_encrypted);
336 
337  const std::string alg_name = OIDS::lookup(alg_id.get_oid());
338  if(alg_name.empty() || alg_name == alg_id.get_oid().as_string())
339  throw PKCS8_Exception("Unknown algorithm OID: " +
340  alg_id.get_oid().as_string());
341 
342  return load_private_key(alg_id, pkcs8_key);
343  }
344 
345 }
346 
347 /*
348 * Extract an encrypted private key and return it
349 */
350 std::unique_ptr<Private_Key> load_key(DataSource& source,
351  std::function<std::string ()> get_pass)
352  {
353  return load_key(source, get_pass, true);
354  }
355 
356 /*
357 * Extract an encrypted private key and return it
358 */
359 std::unique_ptr<Private_Key> load_key(DataSource& source,
360  const std::string& pass)
361  {
362  return load_key(source, [pass]() { return pass; }, true);
363  }
364 
365 /*
366 * Extract an unencrypted private key and return it
367 */
368 std::unique_ptr<Private_Key> load_key(DataSource& source)
369  {
370  auto fail_fn = []() -> std::string {
371  throw PKCS8_Exception("Internal error: Attempt to read password for unencrypted key");
372  };
373 
374  return load_key(source, fail_fn, false);
375  }
376 
377 /*
378 * Make a copy of this private key
379 */
380 std::unique_ptr<Private_Key> copy_key(const Private_Key& key)
381  {
382  DataSource_Memory source(PEM_encode(key));
383  return PKCS8::load_key(source);
384  }
385 
386 /*
387 * Extract an encrypted private key and return it
388 */
391  std::function<std::string ()> get_pass)
392  {
393  BOTAN_UNUSED(rng);
394  return PKCS8::load_key(source, get_pass).release();
395  }
396 
397 /*
398 * Extract an encrypted private key and return it
399 */
402  const std::string& pass)
403  {
404  BOTAN_UNUSED(rng);
405  return PKCS8::load_key(source, pass).release();
406  }
407 
408 /*
409 * Extract an unencrypted private key and return it
410 */
413  {
414  BOTAN_UNUSED(rng);
415  return PKCS8::load_key(source).release();
416  }
417 
418 #if defined(BOTAN_TARGET_OS_HAS_FILESYSTEM)
419 
420 /*
421 * Extract an encrypted private key and return it
422 */
423 Private_Key* load_key(const std::string& fsname,
425  std::function<std::string ()> get_pass)
426  {
427  BOTAN_UNUSED(rng);
428  DataSource_Stream in(fsname);
429  return PKCS8::load_key(in, get_pass).release();
430  }
431 
432 /*
433 * Extract an encrypted private key and return it
434 */
435 Private_Key* load_key(const std::string& fsname,
436  RandomNumberGenerator& rng,
437  const std::string& pass)
438  {
439  BOTAN_UNUSED(rng);
440  DataSource_Stream in(fsname);
441  return PKCS8::load_key(in, [pass]() { return pass; }).release();
442  }
443 
444 /*
445 * Extract an unencrypted private key and return it
446 */
447 Private_Key* load_key(const std::string& fsname,
448  RandomNumberGenerator& rng)
449  {
450  BOTAN_UNUSED(rng);
451  DataSource_Stream in(fsname);
452  return PKCS8::load_key(in).release();
453  }
454 #endif
455 
456 /*
457 * Make a copy of this private key
458 */
461  {
462  BOTAN_UNUSED(rng);
463  return PKCS8::copy_key(key).release();
464  }
465 
466 
467 
468 }
469 
470 }
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:380
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:275
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:230
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:278
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:294
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:305
#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:263
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:88
std::unique_ptr< Private_Key > load_key(DataSource &source, std::function< std::string()> get_pass)
Definition: pkcs8.cpp:350
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:311