/*
 * Copyright (c) 2017 Cisco and/or its affiliates.
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at:
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

/**
 * @file parc_X509Certificate.h
 * @ingroup security
 * @brief The API for a generic  certificate.
 *
 */

#ifndef libparc_parc_X509Certificate_h
#define libparc_parc_X509Certificate_h

#include <parc/security/parc_Certificate.h>
#include <parc/security/parc_KeyType.h>

struct parc_X509_certificate;
typedef struct parc_X509_certificate PARCX509Certificate;

extern PARCCertificateInterface *PARCX509CertificateInterface;

/**
 * Create a `PARCX509Certificate` from a PEM-encoded file.
 *
 * @param [in] filename A nul-terminated path to a certificate file.
 *
 * @return NULL The memory could not be allocated.
 * @return non-NULL A newly allocated `PARCX509Certificate`.
 *
 * Example:
 * @code
 * {
 *     char *pathToCertificate = "file.pem";
 *     PARCX509Certificate *certificate = parcX509Certificate_CreateFromPEMFile(pathToCertificate);
 * }
 * @endcode
 */
PARCX509Certificate *parcX509Certificate_CreateFromPEMFile(const char *filename);

/**
 * Create a `PARCX509Certificate` from a DER-encoded buffer.
 *
 * @param [in] buffer A `PARCBuffer` instance containing the DER-encoded certificate.
 *
 * @return NULL The memory could not be allocated.
 * @return non-NULL A newly allocated `PARCX509Certificate`.
 *
 * Example:
 * @code
 * {
 *     PARCBuffer *certificateBuffer = ...
 *     PARCX509Certificate *certificate = parcX509Certificate_CreateFromDERBuffer(certificateBuffer);
 * }
 * @endcode
 */
PARCX509Certificate *parcX509Certificate_CreateFromDERBuffer(const PARCBuffer *buffer);

// TODO
PARCX509Certificate *parcX509Certificate_CreateSelfSignedCertificate(PARCBuffer **privateKey, char *subjectName, int keyLength, size_t valdityDays, PARCKeyType ketType);

/**
 * Increase the number of references to a `PARCX509Certificate` instance.
 *
 * Note that a new `PARCX509Certificate` is not created,
 * only that the given `PARCX509Certificate` reference count is incremented.
 * Discard the reference by invoking {@link parcX509Certificate_Release}.
 *
 * @param [in] certificate A pointer to the original instance.
 * @return The value of the input parameter @p instance.
 *
 * Example:
 * @code
 * {
 *     PARCX509Certificate *x = parcX509Certificate_CreateFromPEMFile(...);
 *     PARCX509Certificate *x2 = parcX509Certificate_Acquire(x);
 *
 *     parcX509Certificate_Release(&x);
 *     parcX509Certificate_Release(&x2);
 * }
 * @endcode
 *
 * @see {@link parcX509Certificate_Release}
 */
PARCX509Certificate *parcX509Certificate_Acquire(const PARCX509Certificate *certificate);

/**
 * Release a previously acquired reference to the specified instance,
 * decrementing the reference count for the instance.
 *
 * The pointer to the instance is set to NULL as a side-effect of this function.
 *
 * If the invocation causes the last reference to the instance to be released,
 * the instance is deallocated and the instance's implementation will perform
 * additional cleanup and release other privately held references.
 *
 * @param [in,out] certificateP A pointer to a pointer to the instance to release.
 *
 * Example:
 * @code
 * {
 *     PARCX509Certificate *x = parcX509Certificate_CreateFromPEMFile(...);
 *
 *     parcX509Certificate_Release(&x);
 * }
 * @endcode
 */
void parcX509Certificate_Release(PARCX509Certificate **certificateP);

/**
 * Retrieve the SHA-256 digest of the DER-encoded certificate.
 *
 * @param [in] certificate A pointer to `PARCX509Certificate` instance.
 *
 * @return The SHA-256 digest of the @p instance.
 *
 * Example:
 * @code
 * {
 *     PARCX509Certificate *x = parcX509Certificate_CreateFromPEMFile(...);
 *
 *     PARCCryptoHash *digest = parcX509Certificate_GetCertificateDigest(x);
 *     // use the digest
 *
 *     parcX509Certificate_Release(&x);
 * }
 * @endcode
 */
PARCCryptoHash *parcX509Certificate_GetCertificateDigest(PARCX509Certificate *certificate);

/**
 * Retrieve the SHA-256 digest of the DER-encoded public key that
 * is contained in the specified `PARCX509Certificate`.
 *
 * @param [in] certificate A pointer to `PARCX509Certificate` instance.
 *
 * @return The SHA-256 digest of the @p instance's public key.
 *
 * Example:
 * @code
 * {
 *     PARCX509Certificate *x = parcX509Certificate_CreateFromPEMFile(...);
 *
 *     PARCCryptoHash *digest = parcX509Certificate_GetCertificateKeyDigest(x);
 *     // use the digest
 *
 *     parcX509Certificate_Release(&x);
 * }
 * @endcode
 */
PARCCryptoHash *parcX509Certificate_GetCertificateKeyDigest(PARCX509Certificate *certificate);

/**
 * Retrieve the DER-encoded representation of the specified `PARCX509Certificate`.
 *
 * @param [in] certificate A pointer to `PARCX509Certificate` instance.
 *
 * @return A newly allocated `PARCBuffer` instance containing the DER-encoded form
 *         of the specified `PARCX509Certificate`.
 *
 * Example:
 * @code
 * {
 *     PARCX509Certificate *x = parcX509Certificate_CreateFromPEMFile(...);
 *
 *     PARCBuffer *certificateDER = parcX509Certificate_GetDEREncodedCertificate(x);
 *     // use the digest
 *
 *     parcX509Certificate_Release(&x);
 * }
 * @endcode
 */
PARCBuffer *parcX509Certificate_GetDEREncodedCertificate(PARCX509Certificate *certificate);

/**
 * Retrieve the DER-encoded representation of the public key contained within
 * the specified `PARCX509Certificate`.
 *
 * @param [in] certificate A pointer to `PARCX509Certificate` instance.
 *
 * @return A newly allocated `PARCBuffer` instance containing the DER-encoded form
 *         of the public key in the `PARCX509Certificate` instance.
 *
 * Example:
 * @code
 * {
 *     PARCX509Certificate *x = parcX509Certificate_CreateFromPEMFile(...);
 *
 *     PARCBuffer *publicKeyDER = parcX509Certificate_GetDEREncodedPublicKey(x);
 *     // use the digest
 *
 *     parcX509Certificate_Release(&x);
 * }
 * @endcode
 */
PARCBuffer *parcX509Certificate_GetDEREncodedPublicKey(PARCX509Certificate *certificate);
#endif // libparc_parc_X509Certificate_h