/*
 * 	security.h - Runtime function declarations for libglacier
 *
 * 	This file is part of Glacier.
 *
 * 	Glacier is free software: you can redistribute it and/or modify it under the terms of the
 * 	GNU Lesser General Public License as published by the Free Software Foundation, either
 * 	version 3 of the License, or (at your option) any later version.
 *
 * 	Glacier is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
 * 	without even the implied warranty of MERCHANTABILITY or FITNESS FOR A
 * 	PARTICULAR PURPOSE. See the GNU Lesser General Public License for more details.
 *
 * 	You should have received a copy of the GNU Lesser General Public License along with Glacier. If
 * 	not, see <https://www.gnu.org/licenses/>.
 */

#ifndef GLACIERSECURITY_H_
#define GLACIERSECURITY_H_

typedef unsigned int uint;
typedef unsigned char uchar;

/*
 * compare_file_hash
 *
 * DESCRIPTION: compare_file_hash compares the SHA256 hashes of a file and its original hash
 * PARAMETERS:
 * 		char ORIG_HASH[] -> The file containing the expected hash result
 * 		char FILE[] -> The file to compare against ORIG_HASH[]
 * RETURN VALUES:
 * 		0 on hashes match, 1 on hashes do not match, -1 on library error
 * CAVEATS:
 * 		None.
 * EXAMPLE:
 * 		compare_file_hash("pkg.sha256sum", "pkg.tar.xz");
 */

/* int compare_file_hash(char ORIG_HASH[], char FILE[]); */

/*
 * gl_print_hash
 *
 * DESCRIPTION: Prints a specified hash string
 * PARAMETERS: unsigned char *hash, unsigned int length
 * RETURNS: 0 on success, 1 on error
 */
int gl_print_hash(uchar *hash, uint length);

/*
 * gl_stash_hash
 *
 * DESCRIPTION: Stores a hash inside a string
 * PARAMETERS: unsigned char *stored_hash, unsigned char *hash, unsigned int length
 * RETURNS: 0 on success, 1 on error
 */
int gl_stash_hash(char *stored_hash, unsigned int stored_hash_size, const uchar *hash, uint length);

/*
 * gl_hash_file
 *
 * DESCRIPTION: Performs a hashing operation on a file and stores the result
 * PARAMETERS: const char *filename, unsigned char *out_hash, unsigned int *out_length
 * RETURNS: 0 on success, 1-6 for different error conditions
 */
int gl_hash_file(const char *filename, unsigned char *out_hash, unsigned int *out_length);

/*
 * gl_verify_signature
 *
 * DESCRIPTION: Verify a package signature against a trusted keyring
 * PARAMETERS: char PACKAGE[], char SIGNATURE[]
 * RETURNS: 0 on success, 1 on verification failure, 2 on file not found
 */
int gl_verify_signature(char PACKAGE[], char SIGNATURE[]);

/*
 * gl_check_integrity
 *
 * DESCRIPTION: Check package integrity by comparing with expected hash
 * PARAMETERS: char PACKAGE[], char EXPECTED_HASH[]
 * RETURNS: 0 on success, 1 on hash mismatch, 2 on file not found or error
 */
int gl_check_integrity(char PACKAGE[], char EXPECTED_HASH[]);

#endif