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      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 #ifndef SYSTEM_KEYMASTER_OPENSSL_UTILS_H_
     18 #define SYSTEM_KEYMASTER_OPENSSL_UTILS_H_
     19 
     20 #include <openssl/bn.h>
     21 #include <openssl/ec.h>
     22 #include <openssl/engine.h>
     23 #include <openssl/evp.h>
     24 #include <openssl/rsa.h>
     25 #include <openssl/x509.h>
     26 
     27 #include <keymaster/UniquePtr.h>
     28 
     29 #include <hardware/keymaster_defs.h>
     30 
     31 namespace keymaster {
     32 
     33 template<typename BlobType> struct TKeymasterBlob;
     34 typedef TKeymasterBlob<keymaster_key_blob_t> KeymasterKeyBlob;
     35 
     36 class EvpMdCtxCleaner {
     37   public:
     38     explicit EvpMdCtxCleaner(EVP_MD_CTX* ctx) : ctx_(ctx) {}
     39     ~EvpMdCtxCleaner() { EVP_MD_CTX_cleanup(ctx_); }
     40 
     41   private:
     42     EVP_MD_CTX* ctx_;
     43 };
     44 
     45 template <typename T, void (*FreeFunc)(T*)> struct OpenSslObjectDeleter {
     46     void operator()(T* p) { FreeFunc(p); }
     47 };
     48 
     49 #define DEFINE_OPENSSL_OBJECT_POINTER(name)                                                        \
     50     typedef OpenSslObjectDeleter<name, name##_free> name##_Delete;                                 \
     51     typedef UniquePtr<name, name##_Delete> name##_Ptr;
     52 
     53 DEFINE_OPENSSL_OBJECT_POINTER(ASN1_BIT_STRING)
     54 DEFINE_OPENSSL_OBJECT_POINTER(ASN1_INTEGER)
     55 DEFINE_OPENSSL_OBJECT_POINTER(ASN1_OBJECT)
     56 DEFINE_OPENSSL_OBJECT_POINTER(ASN1_OCTET_STRING)
     57 DEFINE_OPENSSL_OBJECT_POINTER(ASN1_TIME)
     58 DEFINE_OPENSSL_OBJECT_POINTER(BN_CTX)
     59 DEFINE_OPENSSL_OBJECT_POINTER(EC_GROUP)
     60 DEFINE_OPENSSL_OBJECT_POINTER(EC_KEY)
     61 DEFINE_OPENSSL_OBJECT_POINTER(EC_POINT)
     62 DEFINE_OPENSSL_OBJECT_POINTER(ENGINE)
     63 DEFINE_OPENSSL_OBJECT_POINTER(EVP_PKEY)
     64 DEFINE_OPENSSL_OBJECT_POINTER(PKCS8_PRIV_KEY_INFO)
     65 DEFINE_OPENSSL_OBJECT_POINTER(RSA)
     66 DEFINE_OPENSSL_OBJECT_POINTER(X509)
     67 DEFINE_OPENSSL_OBJECT_POINTER(X509_EXTENSION)
     68 DEFINE_OPENSSL_OBJECT_POINTER(X509_NAME)
     69 
     70 typedef OpenSslObjectDeleter<BIGNUM, BN_free> BIGNUM_Delete;
     71 typedef UniquePtr<BIGNUM, BIGNUM_Delete> BIGNUM_Ptr;
     72 
     73 keymaster_error_t ec_get_group_size(const EC_GROUP* group, size_t* key_size_bits);
     74 EC_GROUP* ec_get_group(keymaster_ec_curve_t curve);
     75 
     76 /**
     77  * Many OpenSSL APIs take ownership of an argument on success but don't free the argument on
     78  * failure. This means we need to tell our scoped pointers when we've transferred ownership, without
     79  * triggering a warning by not using the result of release().
     80  */
     81 template <typename T, typename Delete_T>
     82 inline void release_because_ownership_transferred(UniquePtr<T, Delete_T>& p) {
     83     T* val __attribute__((unused)) = p.release();
     84 }
     85 
     86 keymaster_error_t convert_pkcs8_blob_to_evp(const uint8_t* key_data, size_t key_length,
     87                                             keymaster_algorithm_t expected_algorithm,
     88                                             UniquePtr<EVP_PKEY, EVP_PKEY_Delete>* pkey);
     89 
     90 keymaster_error_t KeyMaterialToEvpKey(keymaster_key_format_t key_format,
     91                                       const KeymasterKeyBlob& key_material,
     92                                       keymaster_algorithm_t expected_algorithm,
     93                                       UniquePtr<EVP_PKEY, EVP_PKEY_Delete>* evp_pkey);
     94 
     95 keymaster_error_t EvpKeyToKeyMaterial(const EVP_PKEY* evp_pkey, KeymasterKeyBlob* key_blob);
     96 
     97 size_t ec_group_size_bits(EC_KEY* ec_key);
     98 
     99 keymaster_error_t GenerateRandom(uint8_t* buf, size_t length);
    100 
    101 }  // namespace keymaster
    102 
    103 #endif  // SYSTEM_KEYMASTER_OPENSSL_UTILS_H_
    104