1/*
2 * Copyright 2014 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 *      http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17#include <openssl/evp.h>
18#include <openssl/x509.h>
19
20#include <keymaster/key_blob.h>
21#include <keymaster/keymaster_defs.h>
22
23#include "asymmetric_key.h"
24#include "dsa_operation.h"
25#include "ecdsa_operation.h"
26#include "openssl_utils.h"
27#include "rsa_operation.h"
28
29namespace keymaster {
30
31const uint32_t RSA_DEFAULT_KEY_SIZE = 2048;
32const uint64_t RSA_DEFAULT_EXPONENT = 65537;
33
34const uint32_t DSA_DEFAULT_KEY_SIZE = 2048;
35
36const uint32_t ECDSA_DEFAULT_KEY_SIZE = 192;
37
38keymaster_error_t AsymmetricKey::LoadKey(const KeyBlob& blob) {
39    UniquePtr<EVP_PKEY, EVP_PKEY_Delete> evp_key(EVP_PKEY_new());
40    if (evp_key.get() == NULL)
41        return KM_ERROR_MEMORY_ALLOCATION_FAILED;
42
43    EVP_PKEY* tmp_pkey = evp_key.get();
44    const uint8_t* key_material = blob.key_material();
45    if (d2i_PrivateKey(evp_key_type(), &tmp_pkey, &key_material, blob.key_material_length()) ==
46        NULL) {
47        return KM_ERROR_INVALID_KEY_BLOB;
48    }
49    if (!EvpToInternal(evp_key.get()))
50        return KM_ERROR_UNKNOWN_ERROR;
51
52    return KM_ERROR_OK;
53}
54
55keymaster_error_t AsymmetricKey::key_material(UniquePtr<uint8_t[]>* material, size_t* size) const {
56    if (material == NULL || size == NULL)
57        return KM_ERROR_OUTPUT_PARAMETER_NULL;
58
59    UniquePtr<EVP_PKEY, EVP_PKEY_Delete> pkey(EVP_PKEY_new());
60    if (pkey.get() == NULL)
61        return KM_ERROR_MEMORY_ALLOCATION_FAILED;
62
63    if (!InternalToEvp(pkey.get()))
64        return KM_ERROR_UNKNOWN_ERROR;
65
66    *size = i2d_PrivateKey(pkey.get(), NULL /* key_data*/);
67    if (*size <= 0)
68        return KM_ERROR_UNKNOWN_ERROR;
69
70    material->reset(new uint8_t[*size]);
71    uint8_t* tmp = material->get();
72    i2d_PrivateKey(pkey.get(), &tmp);
73
74    return KM_ERROR_OK;
75}
76
77keymaster_error_t AsymmetricKey::formatted_key_material(keymaster_key_format_t format,
78                                                        UniquePtr<uint8_t[]>* material,
79                                                        size_t* size) const {
80    if (format != KM_KEY_FORMAT_X509)
81        return KM_ERROR_UNSUPPORTED_KEY_FORMAT;
82
83    if (material == NULL || size == NULL)
84        return KM_ERROR_OUTPUT_PARAMETER_NULL;
85
86    UniquePtr<EVP_PKEY, EVP_PKEY_Delete> pkey(EVP_PKEY_new());
87    if (!InternalToEvp(pkey.get()))
88        return KM_ERROR_UNKNOWN_ERROR;
89
90    int key_data_length = i2d_PUBKEY(pkey.get(), NULL);
91    if (key_data_length <= 0)
92        return KM_ERROR_UNKNOWN_ERROR;
93
94    material->reset(new uint8_t[key_data_length]);
95    if (material->get() == NULL)
96        return KM_ERROR_MEMORY_ALLOCATION_FAILED;
97
98    uint8_t* tmp = material->get();
99    if (i2d_PUBKEY(pkey.get(), &tmp) != key_data_length) {
100        material->reset();
101        return KM_ERROR_UNKNOWN_ERROR;
102    }
103
104    *size = key_data_length;
105    return KM_ERROR_OK;
106}
107
108Operation* AsymmetricKey::CreateOperation(keymaster_purpose_t purpose, keymaster_error_t* error) {
109    keymaster_digest_t digest;
110    if (!authorizations().GetTagValue(TAG_DIGEST, &digest) || digest != KM_DIGEST_NONE) {
111        *error = KM_ERROR_UNSUPPORTED_DIGEST;
112        return NULL;
113    }
114
115    keymaster_padding_t padding;
116    if (!authorizations().GetTagValue(TAG_PADDING, &padding) || padding != KM_PAD_NONE) {
117        *error = KM_ERROR_UNSUPPORTED_PADDING_MODE;
118        return NULL;
119    }
120
121    return CreateOperation(purpose, digest, padding, error);
122}
123
124/* static */
125RsaKey* RsaKey::GenerateKey(const AuthorizationSet& key_description, const Logger& logger,
126                            keymaster_error_t* error) {
127    if (!error)
128        return NULL;
129
130    AuthorizationSet authorizations(key_description);
131
132    uint64_t public_exponent = RSA_DEFAULT_EXPONENT;
133    if (!authorizations.GetTagValue(TAG_RSA_PUBLIC_EXPONENT, &public_exponent))
134        authorizations.push_back(Authorization(TAG_RSA_PUBLIC_EXPONENT, public_exponent));
135
136    uint32_t key_size = RSA_DEFAULT_KEY_SIZE;
137    if (!authorizations.GetTagValue(TAG_KEY_SIZE, &key_size))
138        authorizations.push_back(Authorization(TAG_KEY_SIZE, key_size));
139
140    UniquePtr<BIGNUM, BIGNUM_Delete> exponent(BN_new());
141    UniquePtr<RSA, RSA_Delete> rsa_key(RSA_new());
142    UniquePtr<EVP_PKEY, EVP_PKEY_Delete> pkey(EVP_PKEY_new());
143    if (rsa_key.get() == NULL || pkey.get() == NULL) {
144        *error = KM_ERROR_MEMORY_ALLOCATION_FAILED;
145        return NULL;
146    }
147
148    if (!BN_set_word(exponent.get(), public_exponent) ||
149        !RSA_generate_key_ex(rsa_key.get(), key_size, exponent.get(), NULL /* callback */)) {
150        *error = KM_ERROR_UNKNOWN_ERROR;
151        return NULL;
152    }
153
154    RsaKey* new_key = new RsaKey(rsa_key.release(), authorizations, logger);
155    *error = new_key ? KM_ERROR_OK : KM_ERROR_MEMORY_ALLOCATION_FAILED;
156    return new_key;
157}
158
159/* static */
160RsaKey* RsaKey::ImportKey(const AuthorizationSet& key_description, EVP_PKEY* pkey,
161                          const Logger& logger, keymaster_error_t* error) {
162    if (!error)
163        return NULL;
164    *error = KM_ERROR_UNKNOWN_ERROR;
165
166    UniquePtr<RSA, RSA_Delete> rsa_key(EVP_PKEY_get1_RSA(pkey));
167    if (!rsa_key.get())
168        return NULL;
169
170    AuthorizationSet authorizations(key_description);
171
172    uint64_t public_exponent;
173    if (authorizations.GetTagValue(TAG_RSA_PUBLIC_EXPONENT, &public_exponent)) {
174        // public_exponent specified, make sure it matches the key
175        UniquePtr<BIGNUM, BIGNUM_Delete> public_exponent_bn(BN_new());
176        if (!BN_set_word(public_exponent_bn.get(), public_exponent))
177            return NULL;
178        if (BN_cmp(public_exponent_bn.get(), rsa_key->e) != 0) {
179            *error = KM_ERROR_IMPORT_PARAMETER_MISMATCH;
180            return NULL;
181        }
182    } else {
183        // public_exponent not specified, use the one from the key.
184        public_exponent = BN_get_word(rsa_key->e);
185        if (public_exponent == 0xffffffffL) {
186            *error = KM_ERROR_IMPORT_PARAMETER_MISMATCH;
187            return NULL;
188        }
189        authorizations.push_back(TAG_RSA_PUBLIC_EXPONENT, public_exponent);
190    }
191
192    uint32_t key_size;
193    if (authorizations.GetTagValue(TAG_KEY_SIZE, &key_size)) {
194        // key_size specified, make sure it matches the key.
195        if (RSA_size(rsa_key.get()) != (int)key_size) {
196            *error = KM_ERROR_IMPORT_PARAMETER_MISMATCH;
197            return NULL;
198        }
199    } else {
200        key_size = RSA_size(rsa_key.get()) * 8;
201        authorizations.push_back(TAG_KEY_SIZE, key_size);
202    }
203
204    keymaster_algorithm_t algorithm;
205    if (authorizations.GetTagValue(TAG_ALGORITHM, &algorithm)) {
206        if (algorithm != KM_ALGORITHM_RSA) {
207            *error = KM_ERROR_IMPORT_PARAMETER_MISMATCH;
208            return NULL;
209        }
210    } else {
211        authorizations.push_back(TAG_ALGORITHM, KM_ALGORITHM_RSA);
212    }
213
214    // Don't bother with the other parameters.  If the necessary padding, digest, purpose, etc. are
215    // missing, the error will be diagnosed when the key is used (when auth checking is
216    // implemented).
217    *error = KM_ERROR_OK;
218    return new RsaKey(rsa_key.release(), authorizations, logger);
219}
220
221RsaKey::RsaKey(const KeyBlob& blob, const Logger& logger, keymaster_error_t* error)
222    : AsymmetricKey(blob, logger) {
223    if (error)
224        *error = LoadKey(blob);
225}
226
227Operation* RsaKey::CreateOperation(keymaster_purpose_t purpose, keymaster_digest_t digest,
228                                   keymaster_padding_t padding, keymaster_error_t* error) {
229    Operation* op;
230    switch (purpose) {
231    case KM_PURPOSE_SIGN:
232        op = new RsaSignOperation(purpose, logger_, digest, padding, rsa_key_.release());
233        break;
234    case KM_PURPOSE_VERIFY:
235        op = new RsaVerifyOperation(purpose, logger_, digest, padding, rsa_key_.release());
236        break;
237    default:
238        *error = KM_ERROR_UNIMPLEMENTED;
239        return NULL;
240    }
241    *error = op ? KM_ERROR_OK : KM_ERROR_MEMORY_ALLOCATION_FAILED;
242    return op;
243}
244
245bool RsaKey::EvpToInternal(const EVP_PKEY* pkey) {
246    rsa_key_.reset(EVP_PKEY_get1_RSA(const_cast<EVP_PKEY*>(pkey)));
247    return rsa_key_.get() != NULL;
248}
249
250bool RsaKey::InternalToEvp(EVP_PKEY* pkey) const {
251    return EVP_PKEY_set1_RSA(pkey, rsa_key_.get()) == 1;
252}
253
254template <keymaster_tag_t Tag>
255static void GetDsaParamData(const AuthorizationSet& auths, TypedTag<KM_BIGNUM, Tag> tag,
256                            keymaster_blob_t* blob) {
257    if (!auths.GetTagValue(tag, blob))
258        blob->data = NULL;
259}
260
261// Store the specified DSA param in auths
262template <keymaster_tag_t Tag>
263static void SetDsaParamData(AuthorizationSet* auths, TypedTag<KM_BIGNUM, Tag> tag, BIGNUM* number) {
264    keymaster_blob_t blob;
265    convert_bn_to_blob(number, &blob);
266    auths->push_back(Authorization(tag, blob));
267    delete[] blob.data;
268}
269
270DsaKey* DsaKey::GenerateKey(const AuthorizationSet& key_description, const Logger& logger,
271                            keymaster_error_t* error) {
272    if (!error)
273        return NULL;
274
275    AuthorizationSet authorizations(key_description);
276
277    keymaster_blob_t g_blob;
278    GetDsaParamData(authorizations, TAG_DSA_GENERATOR, &g_blob);
279
280    keymaster_blob_t p_blob;
281    GetDsaParamData(authorizations, TAG_DSA_P, &p_blob);
282
283    keymaster_blob_t q_blob;
284    GetDsaParamData(authorizations, TAG_DSA_Q, &q_blob);
285
286    uint32_t key_size = DSA_DEFAULT_KEY_SIZE;
287    if (!authorizations.GetTagValue(TAG_KEY_SIZE, &key_size))
288        authorizations.push_back(Authorization(TAG_KEY_SIZE, key_size));
289
290    UniquePtr<DSA, DSA_Delete> dsa_key(DSA_new());
291    UniquePtr<EVP_PKEY, EVP_PKEY_Delete> pkey(EVP_PKEY_new());
292    if (dsa_key.get() == NULL || pkey.get() == NULL) {
293        *error = KM_ERROR_MEMORY_ALLOCATION_FAILED;
294        return NULL;
295    }
296
297    // If anything goes wrong in the next section, it's a param problem.
298    *error = KM_ERROR_INVALID_DSA_PARAMS;
299
300    if (g_blob.data == NULL && p_blob.data == NULL && q_blob.data == NULL) {
301        logger.info("DSA parameters unspecified, generating them for key size %d", key_size);
302        if (!DSA_generate_parameters_ex(dsa_key.get(), key_size, NULL /* seed */, 0 /* seed_len */,
303                                        NULL /* counter_ret */, NULL /* h_ret */,
304                                        NULL /* callback */)) {
305            logger.severe("DSA parameter generation failed.");
306            return NULL;
307        }
308
309        SetDsaParamData(&authorizations, TAG_DSA_GENERATOR, dsa_key->g);
310        SetDsaParamData(&authorizations, TAG_DSA_P, dsa_key->p);
311        SetDsaParamData(&authorizations, TAG_DSA_Q, dsa_key->q);
312    } else if (g_blob.data == NULL || p_blob.data == NULL || q_blob.data == NULL) {
313        logger.severe("Some DSA parameters provided.  Provide all or none");
314        return NULL;
315    } else {
316        // All params provided. Use them.
317        dsa_key->g = BN_bin2bn(g_blob.data, g_blob.data_length, NULL);
318        dsa_key->p = BN_bin2bn(p_blob.data, p_blob.data_length, NULL);
319        dsa_key->q = BN_bin2bn(q_blob.data, q_blob.data_length, NULL);
320
321        if (dsa_key->g == NULL || dsa_key->p == NULL || dsa_key->q == NULL) {
322            return NULL;
323        }
324    }
325
326    if (!DSA_generate_key(dsa_key.get())) {
327        *error = KM_ERROR_UNKNOWN_ERROR;
328        return NULL;
329    }
330
331    DsaKey* new_key = new DsaKey(dsa_key.release(), authorizations, logger);
332    *error = new_key ? KM_ERROR_OK : KM_ERROR_MEMORY_ALLOCATION_FAILED;
333    return new_key;
334}
335
336template <keymaster_tag_t T>
337keymaster_error_t GetOrCheckDsaParam(TypedTag<KM_BIGNUM, T> tag, BIGNUM* bn,
338                                     AuthorizationSet* auths) {
339    keymaster_blob_t blob;
340    if (auths->GetTagValue(tag, &blob)) {
341        // value specified, make sure it matches
342        UniquePtr<BIGNUM, BIGNUM_Delete> extracted_bn(BN_bin2bn(blob.data, blob.data_length, NULL));
343        if (extracted_bn.get() == NULL)
344            return KM_ERROR_MEMORY_ALLOCATION_FAILED;
345        if (BN_cmp(extracted_bn.get(), bn) != 0)
346            return KM_ERROR_IMPORT_PARAMETER_MISMATCH;
347    } else {
348        // value not specified, add it
349        UniquePtr<uint8_t[]> data(new uint8_t[BN_num_bytes(bn)]);
350        BN_bn2bin(bn, data.get());
351        auths->push_back(tag, data.get(), BN_num_bytes(bn));
352    }
353    return KM_ERROR_OK;
354}
355
356/* static */
357size_t DsaKey::key_size_bits(DSA* dsa_key) {
358    // Openssl provides no convenient way to get a DSA key size, but dsa_key->p is L bits long.
359    // There may be some leading zeros that mess up this calculation, but DSA key sizes are also
360    // constrained to be multiples of 64 bits.  So the key size is the bit length of p rounded up to
361    // the nearest 64.
362    return ((BN_num_bytes(dsa_key->p) * 8) + 63) / 64 * 64;
363}
364
365/* static */
366DsaKey* DsaKey::ImportKey(const AuthorizationSet& key_description, EVP_PKEY* pkey,
367                          const Logger& logger, keymaster_error_t* error) {
368    if (!error)
369        return NULL;
370    *error = KM_ERROR_UNKNOWN_ERROR;
371
372    UniquePtr<DSA, DSA_Delete> dsa_key(EVP_PKEY_get1_DSA(pkey));
373    if (!dsa_key.get())
374        return NULL;
375
376    AuthorizationSet authorizations(key_description);
377
378    *error = GetOrCheckDsaParam(TAG_DSA_GENERATOR, dsa_key->g, &authorizations);
379    if (*error != KM_ERROR_OK)
380        return NULL;
381
382    *error = GetOrCheckDsaParam(TAG_DSA_P, dsa_key->p, &authorizations);
383    if (*error != KM_ERROR_OK)
384        return NULL;
385
386    *error = GetOrCheckDsaParam(TAG_DSA_Q, dsa_key->q, &authorizations);
387    if (*error != KM_ERROR_OK)
388        return NULL;
389
390    // There's no convenient way to get a DSA key size, but dsa_key->p is L bits long.  There may be
391    // some leading zeros that mess up this calculation, but DSA key sizes are also constrained to
392    // be multiples of 64 bits.  So the bit length of p, rounded up to the nearest 64 bits, is the
393    // key size.
394    uint32_t extracted_key_size_bits = ((BN_num_bytes(dsa_key->p) * 8) + 63) / 64 * 64;
395
396    uint32_t key_size_bits;
397    if (authorizations.GetTagValue(TAG_KEY_SIZE, &key_size_bits)) {
398        // key_size_bits specified, make sure it matches the key.
399        if (key_size_bits != extracted_key_size_bits) {
400            *error = KM_ERROR_IMPORT_PARAMETER_MISMATCH;
401            return NULL;
402        }
403    } else {
404        // key_size_bits not specified, add it.
405        authorizations.push_back(TAG_KEY_SIZE, extracted_key_size_bits);
406    }
407
408    keymaster_algorithm_t algorithm;
409    if (authorizations.GetTagValue(TAG_ALGORITHM, &algorithm)) {
410        if (algorithm != KM_ALGORITHM_DSA) {
411            *error = KM_ERROR_IMPORT_PARAMETER_MISMATCH;
412            return NULL;
413        }
414    } else {
415        authorizations.push_back(TAG_ALGORITHM, KM_ALGORITHM_DSA);
416    }
417
418    // Don't bother with the other parameters.  If the necessary padding, digest, purpose, etc. are
419    // missing, the error will be diagnosed when the key is used (when auth checking is
420    // implemented).
421    *error = KM_ERROR_OK;
422    return new DsaKey(dsa_key.release(), authorizations, logger);
423}
424
425DsaKey::DsaKey(const KeyBlob& blob, const Logger& logger, keymaster_error_t* error)
426    : AsymmetricKey(blob, logger) {
427    if (error)
428        *error = LoadKey(blob);
429}
430
431Operation* DsaKey::CreateOperation(keymaster_purpose_t purpose, keymaster_digest_t digest,
432                                   keymaster_padding_t padding, keymaster_error_t* error) {
433    Operation* op;
434    switch (purpose) {
435    case KM_PURPOSE_SIGN:
436        op = new DsaSignOperation(purpose, logger_, digest, padding, dsa_key_.release());
437        break;
438    case KM_PURPOSE_VERIFY:
439        op = new DsaVerifyOperation(purpose, logger_, digest, padding, dsa_key_.release());
440        break;
441    default:
442        *error = KM_ERROR_UNIMPLEMENTED;
443        return NULL;
444    }
445    *error = op ? KM_ERROR_OK : KM_ERROR_MEMORY_ALLOCATION_FAILED;
446    return op;
447}
448
449bool DsaKey::EvpToInternal(const EVP_PKEY* pkey) {
450    dsa_key_.reset(EVP_PKEY_get1_DSA(const_cast<EVP_PKEY*>(pkey)));
451    return dsa_key_.get() != NULL;
452}
453
454bool DsaKey::InternalToEvp(EVP_PKEY* pkey) const {
455    return EVP_PKEY_set1_DSA(pkey, dsa_key_.get()) == 1;
456}
457
458/* static */
459EcdsaKey* EcdsaKey::GenerateKey(const AuthorizationSet& key_description, const Logger& logger,
460                                keymaster_error_t* error) {
461    if (!error)
462        return NULL;
463
464    AuthorizationSet authorizations(key_description);
465
466    uint32_t key_size = ECDSA_DEFAULT_KEY_SIZE;
467    if (!authorizations.GetTagValue(TAG_KEY_SIZE, &key_size))
468        authorizations.push_back(Authorization(TAG_KEY_SIZE, key_size));
469
470    UniquePtr<EC_KEY, ECDSA_Delete> ecdsa_key(EC_KEY_new());
471    UniquePtr<EVP_PKEY, EVP_PKEY_Delete> pkey(EVP_PKEY_new());
472    if (ecdsa_key.get() == NULL || pkey.get() == NULL) {
473        *error = KM_ERROR_MEMORY_ALLOCATION_FAILED;
474        return NULL;
475    }
476
477    UniquePtr<EC_GROUP, EC_GROUP_Delete> group(choose_group(key_size));
478    if (group.get() == NULL) {
479        // Technically, could also have been a memory allocation problem.
480        *error = KM_ERROR_UNSUPPORTED_KEY_SIZE;
481        return NULL;
482    }
483
484    EC_GROUP_set_point_conversion_form(group.get(), POINT_CONVERSION_UNCOMPRESSED);
485    EC_GROUP_set_asn1_flag(group.get(), OPENSSL_EC_NAMED_CURVE);
486
487    if (EC_KEY_set_group(ecdsa_key.get(), group.get()) != 1 ||
488        EC_KEY_generate_key(ecdsa_key.get()) != 1 || EC_KEY_check_key(ecdsa_key.get()) < 0) {
489        *error = KM_ERROR_UNKNOWN_ERROR;
490        return NULL;
491    }
492
493    EcdsaKey* new_key = new EcdsaKey(ecdsa_key.release(), authorizations, logger);
494    *error = new_key ? KM_ERROR_OK : KM_ERROR_MEMORY_ALLOCATION_FAILED;
495    return new_key;
496}
497
498/* static */
499EcdsaKey* EcdsaKey::ImportKey(const AuthorizationSet& key_description, EVP_PKEY* pkey,
500                              const Logger& logger, keymaster_error_t* error) {
501    if (!error)
502        return NULL;
503    *error = KM_ERROR_UNKNOWN_ERROR;
504
505    UniquePtr<EC_KEY, ECDSA_Delete> ecdsa_key(EVP_PKEY_get1_EC_KEY(pkey));
506    if (!ecdsa_key.get())
507        return NULL;
508
509    AuthorizationSet authorizations(key_description);
510
511    size_t extracted_key_size_bits;
512    *error = get_group_size(*EC_KEY_get0_group(ecdsa_key.get()), &extracted_key_size_bits);
513    if (*error != KM_ERROR_OK)
514        return NULL;
515
516    uint32_t key_size_bits;
517    if (authorizations.GetTagValue(TAG_KEY_SIZE, &key_size_bits)) {
518        // key_size_bits specified, make sure it matches the key.
519        if (key_size_bits != extracted_key_size_bits) {
520            *error = KM_ERROR_IMPORT_PARAMETER_MISMATCH;
521            return NULL;
522        }
523    } else {
524        // key_size_bits not specified, add it.
525        authorizations.push_back(TAG_KEY_SIZE, extracted_key_size_bits);
526    }
527
528    keymaster_algorithm_t algorithm;
529    if (authorizations.GetTagValue(TAG_ALGORITHM, &algorithm)) {
530        if (algorithm != KM_ALGORITHM_ECDSA) {
531            *error = KM_ERROR_IMPORT_PARAMETER_MISMATCH;
532            return NULL;
533        }
534    } else {
535        authorizations.push_back(TAG_ALGORITHM, KM_ALGORITHM_ECDSA);
536    }
537
538    // Don't bother with the other parameters.  If the necessary padding, digest, purpose, etc. are
539    // missing, the error will be diagnosed when the key is used (when auth checking is
540    // implemented).
541    *error = KM_ERROR_OK;
542    return new EcdsaKey(ecdsa_key.release(), authorizations, logger);
543}
544
545/* static */
546EC_GROUP* EcdsaKey::choose_group(size_t key_size_bits) {
547    switch (key_size_bits) {
548    case 192:
549        return EC_GROUP_new_by_curve_name(NID_X9_62_prime192v1);
550        break;
551    case 224:
552        return EC_GROUP_new_by_curve_name(NID_secp224r1);
553        break;
554    case 256:
555        return EC_GROUP_new_by_curve_name(NID_X9_62_prime256v1);
556        break;
557    case 384:
558        return EC_GROUP_new_by_curve_name(NID_secp384r1);
559        break;
560    case 521:
561        return EC_GROUP_new_by_curve_name(NID_secp521r1);
562        break;
563    default:
564        return NULL;
565        break;
566    }
567}
568
569/* static */
570keymaster_error_t EcdsaKey::get_group_size(const EC_GROUP& group, size_t* key_size_bits) {
571    switch (EC_GROUP_get_curve_name(&group)) {
572    case NID_X9_62_prime192v1:
573        *key_size_bits = 192;
574        break;
575    case NID_secp224r1:
576        *key_size_bits = 224;
577        break;
578    case NID_X9_62_prime256v1:
579        *key_size_bits = 256;
580        break;
581    case NID_secp384r1:
582        *key_size_bits = 384;
583        break;
584    case NID_secp521r1:
585        *key_size_bits = 521;
586        break;
587    default:
588        return KM_ERROR_UNSUPPORTED_EC_FIELD;
589    }
590    return KM_ERROR_OK;
591}
592
593EcdsaKey::EcdsaKey(const KeyBlob& blob, const Logger& logger, keymaster_error_t* error)
594    : AsymmetricKey(blob, logger) {
595    if (error)
596        *error = LoadKey(blob);
597}
598
599Operation* EcdsaKey::CreateOperation(keymaster_purpose_t purpose, keymaster_digest_t digest,
600                                     keymaster_padding_t padding, keymaster_error_t* error) {
601    Operation* op;
602    switch (purpose) {
603    case KM_PURPOSE_SIGN:
604        op = new EcdsaSignOperation(purpose, logger_, digest, padding, ecdsa_key_.release());
605        break;
606    case KM_PURPOSE_VERIFY:
607        op = new EcdsaVerifyOperation(purpose, logger_, digest, padding, ecdsa_key_.release());
608        break;
609    default:
610        *error = KM_ERROR_UNIMPLEMENTED;
611        return NULL;
612    }
613    *error = op ? KM_ERROR_OK : KM_ERROR_MEMORY_ALLOCATION_FAILED;
614    return op;
615}
616
617bool EcdsaKey::EvpToInternal(const EVP_PKEY* pkey) {
618    ecdsa_key_.reset(EVP_PKEY_get1_EC_KEY(const_cast<EVP_PKEY*>(pkey)));
619    return ecdsa_key_.get() != NULL;
620}
621
622bool EcdsaKey::InternalToEvp(EVP_PKEY* pkey) const {
623    return EVP_PKEY_set1_EC_KEY(pkey, ecdsa_key_.get()) == 1;
624}
625
626}  // namespace keymaster
627