libkeymaster/keymaster_mobicore.cpp

   1 /*
   2  * Copyright (C) 2012 Samsung Electronics Co., LTD
   3  * Copyright (C) 2012 The Android Open Source Project
   4  *
   5  * Licensed under the Apache License, Version 2.0 (the "License");
   6  * you may not use this file except in compliance with the License.
   7  * You may obtain a copy of the License at
   8  *
   9  *      http://www.apache.org/licenses/LICENSE-2.0
  10  *
  11  * Unless required by applicable law or agreed to in writing, software
  12  * distributed under the License is distributed on an "AS IS" BASIS,
  13  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  14  * See the License for the specific language governing permissions and
  15  * limitations under the License.
  16  */
  17
  18 #include <errno.h>
  19 #include <string.h>
  20 #include <stdint.h>
  21
  22 #include <hardware/hardware.h>
  23 #include <hardware/keymaster0.h>
  24
  25 #include <openssl/evp.h>
  26 #include <openssl/bio.h>
  27 #include <openssl/rsa.h>
  28 #include <openssl/err.h>
  29 #include <openssl/x509.h>
  30
  31 #include <UniquePtr.h>
  32
  33 #define LOG_TAG "ExynosKeyMaster"
  34 #include <cutils/log.h>
  35
  36 #include <tlcTeeKeymaster_if.h>
  37
  38 #define RSA_KEY_BUFFER_SIZE   1536
  39 #define RSA_KEY_MAX_SIZE      (2048 >> 3)
  40
  41 struct BIGNUM_Delete {
  42     void operator()(BIGNUM* p) const {
  43         BN_free(p);
  44     }
  45 };
  46 typedef UniquePtr<BIGNUM, BIGNUM_Delete> Unique_BIGNUM;
  47
  48 struct EVP_PKEY_Delete {
  49     void operator()(EVP_PKEY* p) const {
  50         EVP_PKEY_free(p);
  51     }
  52 };
  53 typedef UniquePtr<EVP_PKEY, EVP_PKEY_Delete> Unique_EVP_PKEY;
  54
  55 struct PKCS8_PRIV_KEY_INFO_Delete {
  56     void operator()(PKCS8_PRIV_KEY_INFO* p) const {
  57         PKCS8_PRIV_KEY_INFO_free(p);
  58     }
  59 };
  60 typedef UniquePtr<PKCS8_PRIV_KEY_INFO, PKCS8_PRIV_KEY_INFO_Delete> Unique_PKCS8_PRIV_KEY_INFO;
  61
  62 struct RSA_Delete {
  63     void operator()(RSA* p) const {
  64         RSA_free(p);
  65     }
  66 };
  67 typedef UniquePtr<RSA, RSA_Delete> Unique_RSA;
  68
  69 typedef UniquePtr<keymaster0_device_t> Unique_keymaster0_device_t;
  70
  71 /**
  72  * Many OpenSSL APIs take ownership of an argument on success but don't free the argument
  73  * on failure. This means we need to tell our scoped pointers when we've transferred ownership,
  74  * without triggering a warning by not using the result of release().
  75  */
  76 #define OWNERSHIP_TRANSFERRED(obj) \
  77     typeof (obj.release()) _dummy __attribute__((unused)) = obj.release()
  78
  79 /*
  80  * Checks this thread's error queue and logs if necessary.
  81  */
  82 static void logOpenSSLError(const char* location) {
  83     int error = ERR_get_error();
  84
  85     if (error != 0) {
  86         char message[256];
  87         ERR_error_string_n(error, message, sizeof(message));
  88         ALOGE("OpenSSL error in %s %d: %s", location, error, message);
  89     }
  90
  91     ERR_clear_error();
  92     ERR_remove_state(0);
  93 }
  94
  95 static int exynos_km_generate_keypair(const keymaster0_device_t* dev,
  96         const keymaster_keypair_t key_type, const void* key_params,
  97         uint8_t** keyBlob, size_t* keyBlobLength) {
  98     teeResult_t ret = TEE_ERR_NONE;
  99
 100     if (key_type != TYPE_RSA) {
 101         ALOGE("Unsupported key type %d", key_type);
 102         return -1;
 103     } else if (key_params == NULL) {
 104         ALOGE("key_params == null");
 105         return -1;
 106     }
 107
 108     keymaster_rsa_keygen_params_t* rsa_params = (keymaster_rsa_keygen_params_t*) key_params;
 109
 110     if ((rsa_params->modulus_size != 512) &&
 111         (rsa_params->modulus_size != 1024) &&
 112         (rsa_params->modulus_size != 2048)) {
 113         ALOGE("key size(%d) is not supported\n", rsa_params->modulus_size);
 114         return -1;
 115     }
 116
 117     UniquePtr<uint8_t> keyDataPtr(reinterpret_cast<uint8_t*>(malloc(RSA_KEY_BUFFER_SIZE)));
 118     if (keyDataPtr.get() == NULL) {
 119         ALOGE("memory allocation is failed");
 120         return -1;
 121     }
 122
 123     ret = TEE_RSAGenerateKeyPair(TEE_KEYPAIR_RSACRT, keyDataPtr.get(), RSA_KEY_BUFFER_SIZE,
 124                                 rsa_params->modulus_size, (uint32_t)rsa_params->public_exponent,
 125                                 keyBlobLength);
 126     if (ret != TEE_ERR_NONE) {
 127         ALOGE("TEE_RSAGenerateKeyPair() is failed: %d", ret);
 128         return -1;
 129     }
 130
 131    *keyBlob = keyDataPtr.release();
 132
 133     return 0;
 134 }
 135
 136 static int exynos_km_import_keypair(const keymaster0_device_t* dev,
 137         const uint8_t* key, const size_t key_length,
 138         uint8_t** key_blob, size_t* key_blob_length) {
 139     uint8_t kbuf[RSA_KEY_BUFFER_SIZE];
 140     teeRsaKeyMeta_t metadata;
 141     uint32_t key_len = 0;
 142     teeResult_t ret = TEE_ERR_NONE;
 143
 144     if (key == NULL) {
 145         ALOGE("input key == NULL");
 146         return -1;
 147     } else if (key_blob == NULL || key_blob_length == NULL) {
 148         ALOGE("output key blob or length == NULL");
 149         return -1;
 150     }
 151
 152     /* decoding */
 153     Unique_PKCS8_PRIV_KEY_INFO pkcs8(d2i_PKCS8_PRIV_KEY_INFO(NULL, &key, key_length));
 154     if (pkcs8.get() == NULL) {
 155         logOpenSSLError("pkcs4.get");
 156         return -1;
 157     }
 158
 159     /* assign to EVP */
 160     Unique_EVP_PKEY pkey(EVP_PKCS82PKEY(pkcs8.get()));
 161     if (pkey.get() == NULL) {
 162         logOpenSSLError("pkey.get");
 163         return -1;
 164     }
 165     OWNERSHIP_TRANSFERRED(pkcs8);
 166
 167     /* change key format */
 168     Unique_RSA rsa(EVP_PKEY_get1_RSA(pkey.get()));
 169     if (rsa.get() == NULL) {
 170         logOpenSSLError("get rsa key format");
 171         return -1;
 172     }
 173
 174     key_len += sizeof(metadata);
 175
 176     metadata.lenpubmod = BN_bn2bin(rsa->n, kbuf + key_len);
 177     key_len += metadata.lenpubmod;
 178     if (metadata.lenpubmod == (512 >> 3))
 179         metadata.keysize = TEE_RSA_KEY_SIZE_512;
 180     else if (metadata.lenpubmod == (1024 >> 3))
 181         metadata.keysize = TEE_RSA_KEY_SIZE_1024;
 182     else if (metadata.lenpubmod == (2048 >> 3))
 183         metadata.keysize = TEE_RSA_KEY_SIZE_2048;
 184     else {
 185         ALOGE("key size(%d) is not supported\n", metadata.lenpubmod << 3);
 186         return -1;
 187     }
 188
 189     metadata.lenpubexp = BN_bn2bin(rsa->e, kbuf + key_len);
 190     key_len += metadata.lenpubexp;
 191
 192     if ((rsa->p != NULL) && (rsa->q != NULL) && (rsa->dmp1 != NULL) &&
 193         (rsa->dmq1 != NULL) && (rsa->iqmp != NULL))
 194     {
 195            metadata.keytype = TEE_KEYPAIR_RSACRT;
 196            metadata.rsacrtpriv.lenp = BN_bn2bin(rsa->p, kbuf + key_len);
 197            key_len += metadata.rsacrtpriv.lenp;
 198            metadata.rsacrtpriv.lenq = BN_bn2bin(rsa->q, kbuf + key_len);
 199            key_len += metadata.rsacrtpriv.lenq;
 200            metadata.rsacrtpriv.lendp = BN_bn2bin(rsa->dmp1, kbuf + key_len);
 201            key_len += metadata.rsacrtpriv.lendp;
 202            metadata.rsacrtpriv.lendq = BN_bn2bin(rsa->dmq1, kbuf + key_len);
 203            key_len += metadata.rsacrtpriv.lendq;
 204            metadata.rsacrtpriv.lenqinv = BN_bn2bin(rsa->iqmp, kbuf + key_len);
 205            key_len += metadata.rsacrtpriv.lenqinv;
 206     } else {
 207            metadata.keytype = TEE_KEYPAIR_RSA;
 208            metadata.rsapriv.lenpriexp = BN_bn2bin(rsa->p, kbuf + key_len);
 209            key_len += metadata.rsapriv.lenprimod;
 210     }
 211     memcpy(kbuf, &metadata, sizeof(metadata));
 212
 213     UniquePtr<uint8_t> outPtr(reinterpret_cast<uint8_t*>(malloc(RSA_KEY_BUFFER_SIZE)));
 214     if (outPtr.get() == NULL) {
 215         ALOGE("memory allocation is failed");
 216         return -1;
 217     }
 218
 219     *key_blob_length = RSA_KEY_BUFFER_SIZE;
 220
 221     ret = TEE_KeyImport(kbuf, key_len, outPtr.get(), key_blob_length);
 222     if (ret != TEE_ERR_NONE) {
 223         ALOGE("TEE_KeyImport() is failed: %d", ret);
 224         return -1;
 225     }
 226
 227     *key_blob = outPtr.release();
 228
 229     return 0;
 230 }
 231
 232 static int exynos_km_get_keypair_public(const struct keymaster0_device* dev,
 233         const uint8_t* key_blob, const size_t key_blob_length,
 234         uint8_t** x509_data, size_t* x509_data_length) {
 235     uint32_t bin_mod_len;
 236     uint32_t bin_exp_len;
 237     teeResult_t ret = TEE_ERR_NONE;
 238
 239     if (x509_data == NULL || x509_data_length == NULL) {
 240         ALOGE("output public key buffer == NULL");
 241         return -1;
 242     }
 243
 244     UniquePtr<uint8_t> binModPtr(reinterpret_cast<uint8_t*>(malloc(RSA_KEY_MAX_SIZE)));
 245     if (binModPtr.get() == NULL) {
 246         ALOGE("memory allocation is failed");
 247         return -1;
 248     }
 249
 250     UniquePtr<uint8_t> binExpPtr(reinterpret_cast<uint8_t*>(malloc(sizeof(uint32_t))));
 251     if (binExpPtr.get() == NULL) {
 252         ALOGE("memory allocation is failed");
 253         return -1;
 254     }
 255
 256     bin_mod_len = RSA_KEY_MAX_SIZE;
 257     bin_exp_len = sizeof(uint32_t);
 258
 259     ret = TEE_GetPubKey(key_blob, key_blob_length, binModPtr.get(), &bin_mod_len, binExpPtr.get(),
 260                         &bin_exp_len);
 261     if (ret != TEE_ERR_NONE) {
 262         ALOGE("TEE_GetPubKey() is failed: %d", ret);
 263         return -1;
 264     }
 265
 266     Unique_BIGNUM bn_mod(BN_new());
 267     if (bn_mod.get() == NULL) {
 268         ALOGE("memory allocation is failed");
 269         return -1;
 270     }
 271
 272     Unique_BIGNUM bn_exp(BN_new());
 273     if (bn_exp.get() == NULL) {
 274         ALOGE("memory allocation is failed");
 275         return -1;
 276     }
 277
 278     BN_bin2bn(binModPtr.get(), bin_mod_len, bn_mod.get());
 279     BN_bin2bn(binExpPtr.get(), bin_exp_len, bn_exp.get());
 280
 281     /* assign to RSA */
 282     Unique_RSA rsa(RSA_new());
 283     if (rsa.get() == NULL) {
 284         logOpenSSLError("rsa.get");
 285         return -1;
 286     }
 287
 288     RSA* rsa_tmp = rsa.get();
 289
 290     rsa_tmp->n = bn_mod.release();
 291     rsa_tmp->e = bn_exp.release();
 292
 293     /* assign to EVP */
 294     Unique_EVP_PKEY pkey(EVP_PKEY_new());
 295     if (pkey.get() == NULL) {
 296         logOpenSSLError("allocate EVP_PKEY");
 297         return -1;
 298     }
 299
 300     if (EVP_PKEY_assign_RSA(pkey.get(), rsa.get()) == 0) {
 301         logOpenSSLError("assing RSA to EVP_PKEY");
 302         return -1;
 303     }
 304     OWNERSHIP_TRANSFERRED(rsa);
 305
 306     /* change to x.509 format */
 307     int len = i2d_PUBKEY(pkey.get(), NULL);
 308     if (len <= 0) {
 309         logOpenSSLError("i2d_PUBKEY");
 310         return -1;
 311     }
 312
 313     UniquePtr<uint8_t> key(static_cast<uint8_t*>(malloc(len)));
 314     if (key.get() == NULL) {
 315         ALOGE("Could not allocate memory for public key data");
 316         return -1;
 317     }
 318
 319     unsigned char* tmp = reinterpret_cast<unsigned char*>(key.get());
 320     if (i2d_PUBKEY(pkey.get(), &tmp) != len) {
 321         logOpenSSLError("Compare results");
 322         return -1;
 323     }
 324
 325     *x509_data_length = len;
 326     *x509_data = key.release();
 327
 328     return 0;
 329 }
 330
 331 static int exynos_km_sign_data(const keymaster0_device_t* dev,
 332         const void* params,
 333         const uint8_t* keyBlob, const size_t keyBlobLength,
 334         const uint8_t* data, const size_t dataLength,
 335         uint8_t** signedData, size_t* signedDataLength) {
 336     teeResult_t ret = TEE_ERR_NONE;
 337
 338     if (data == NULL) {
 339         ALOGE("input data to sign == NULL");
 340         return -1;
 341     } else if (signedData == NULL || signedDataLength == NULL) {
 342         ALOGE("output signature buffer == NULL");
 343         return -1;
 344     }
 345
 346     keymaster_rsa_sign_params_t* sign_params = (keymaster_rsa_sign_params_t*) params;
 347     if (sign_params->digest_type != DIGEST_NONE) {
 348         ALOGE("Cannot handle digest type %d", sign_params->digest_type);
 349         return -1;
 350     } else if (sign_params->padding_type != PADDING_NONE) {
 351         ALOGE("Cannot handle padding type %d", sign_params->padding_type);
 352         return -1;
 353     }
 354
 355     UniquePtr<uint8_t> signedDataPtr(reinterpret_cast<uint8_t*>(malloc(RSA_KEY_MAX_SIZE)));
 356     if (signedDataPtr.get() == NULL) {
 357         ALOGE("memory allocation is failed");
 358         return -1;
 359     }
 360
 361     *signedDataLength = RSA_KEY_MAX_SIZE;
 362
 363     /* binder gives us read-only mappings we can't use with mobicore */
 364     void *tmpData = malloc(dataLength);
 365     memcpy(tmpData, data, dataLength);
 366     ret = TEE_RSASign(keyBlob, keyBlobLength, (const uint8_t *)tmpData, dataLength, signedDataPtr.get(),
 367                         signedDataLength, TEE_RSA_NODIGEST_NOPADDING);
 368     free(tmpData);
 369     if (ret != TEE_ERR_NONE) {
 370         ALOGE("TEE_RSASign() is failed: %d", ret);
 371         return -1;
 372     }
 373
 374     *signedData = signedDataPtr.release();
 375
 376     return 0;
 377 }
 378
 379 static int exynos_km_verify_data(const keymaster0_device_t* dev,
 380         const void* params,
 381         const uint8_t* keyBlob, const size_t keyBlobLength,
 382         const uint8_t* signedData, const size_t signedDataLength,
 383         const uint8_t* signature, const size_t signatureLength) {
 384     bool result;
 385     teeResult_t ret = TEE_ERR_NONE;
 386
 387     if (signedData == NULL || signature == NULL) {
 388         ALOGE("data or signature buffers == NULL");
 389         return -1;
 390     }
 391
 392     keymaster_rsa_sign_params_t* sign_params = (keymaster_rsa_sign_params_t*) params;
 393     if (sign_params->digest_type != DIGEST_NONE) {
 394         ALOGE("Cannot handle digest type %d", sign_params->digest_type);
 395         return -1;
 396     } else if (sign_params->padding_type != PADDING_NONE) {
 397         ALOGE("Cannot handle padding type %d", sign_params->padding_type);
 398         return -1;
 399     } else if (signatureLength != signedDataLength) {
 400         ALOGE("signed data length must be signature length");
 401         return -1;
 402     }
 403
 404     void *tmpSignedData = malloc(signedDataLength);
 405     memcpy(tmpSignedData, signedData, signedDataLength);
 406     void *tmpSig = malloc(signatureLength);
 407     memcpy(tmpSig, signature, signatureLength);
 408     ret = TEE_RSAVerify(keyBlob, keyBlobLength, (const uint8_t*)tmpSignedData, signedDataLength, (const uint8_t *)tmpSig,
 409                         signatureLength, TEE_RSA_NODIGEST_NOPADDING, &result);
 410     free(tmpSignedData);
 411     free(tmpSig);
 412     if (ret != TEE_ERR_NONE) {
 413         ALOGE("TEE_RSAVerify() is failed: %d", ret);
 414         return -1;
 415     }
 416
 417     return (result == true) ? 0 : -1;
 418 }
 419
 420 /* Close an opened Exynos KM instance */
 421 static int exynos_km_close(hw_device_t *dev) {
 422     free(dev);
 423     return 0;
 424 }
 425
 426 /*
 427  * Generic device handling
 428  */
 429 static int exynos_km_open(const hw_module_t* module, const char* name,
 430         hw_device_t** device) {
 431     if (strcmp(name, KEYSTORE_KEYMASTER) != 0)
 432         return -EINVAL;
 433
 434     Unique_keymaster0_device_t dev(new keymaster0_device_t);
 435     if (dev.get() == NULL)
 436         return -ENOMEM;
 437
 438     dev->common.tag = HARDWARE_DEVICE_TAG;
 439     dev->common.version = 1;
 440     dev->common.module = (struct hw_module_t*) module;
 441     dev->common.close = exynos_km_close;
 442
 443     dev->flags = 0;
 444
 445     dev->generate_keypair = exynos_km_generate_keypair;
 446     dev->import_keypair = exynos_km_import_keypair;
 447     dev->get_keypair_public = exynos_km_get_keypair_public;
 448     dev->delete_keypair = NULL;
 449     dev->delete_all = NULL;
 450     dev->sign_data = exynos_km_sign_data;
 451     dev->verify_data = exynos_km_verify_data;
 452
 453     ERR_load_crypto_strings();
 454     ERR_load_BIO_strings();
 455
 456     *device = reinterpret_cast<hw_device_t*>(dev.release());
 457
 458     return 0;
 459 }
 460
 461 static struct hw_module_methods_t keystore_module_methods = {
 462     open: exynos_km_open,
 463 };
 464
 465 struct keystore_module HAL_MODULE_INFO_SYM
 466 __attribute__ ((visibility ("default"))) = {
 467     common: {
 468         tag: HARDWARE_MODULE_TAG,
 469         version_major: 1,
 470         version_minor: 0,
 471         id: KEYSTORE_HARDWARE_MODULE_ID,
 472         name: "Keymaster Exynos HAL",
 473         author: "Samsung S.LSI",
 474         methods: &keystore_module_methods,
 475         dso: 0,
 476         reserved: {},
 477     },
 478 };