rsa_dec_main.c

#include <unistd.h>
#include <getopt.h>
#include "rsa_util.h"
#include "rsa_dec.h"
#include "rsa.h"

static opt_t options_decrypter[] = {
	{RSA_OPT_FILE, 'f', "file", required_argument, ARG " is the input file "
		"to decrypt"},
	{RSA_OPT_ORIG_FILE, 'o', "original", no_argument, "keep the original "
		"file. if this option is not set the file will be deleted "
		"after it has been decrypted"},
	{RSA_OPT_KEYGEN, 'g', "generate", required_argument, "generate an RSA "
		"public/private key pair. " ARG " is its name"},
	{RSA_OPT_ENC_INFO_ONLY, 'i', "info", no_argument, "get info regarding "
		"an encrypted file. this depends on possessing the required "
		"private key"},
	{ RSA_OPT_MAX }
};

/* either encryption or decryption task are to be performed */
static int parse_args_finalize_decrypter(unsigned int *flags, int actions)
{
	if (!actions && !(*flags & OPT_FLAG(RSA_OPT_KEYGEN)))
		*flags |= OPT_FLAG(RSA_OPT_DECRYPT);

	/* test for non compatible options with encrypt/decrypt */
	if ((*flags & OPT_FLAG(RSA_OPT_DECRYPT)) &&
		!(*flags & OPT_FLAG(RSA_OPT_FILE))) {
		rsa_error_message(RSA_ERR_NOFILE);
		return -1;
	}

	return 0;
}

static int parse_args_decrypter(int opt, unsigned int *flags)
{
	switch (opt_short2code(options_decrypter, opt))
	{
	case RSA_OPT_FILE:
		OPT_ADD(flags, RSA_OPT_FILE);
		if (rsa_set_file_name(optarg))
			return -1;
		break;
	case RSA_OPT_KEYGEN:
		OPT_ADD(flags, RSA_OPT_KEYGEN);
		if (rsa_set_key_data(optarg))
			return -1;
		break;
	case RSA_OPT_ENC_INFO_ONLY:
		OPT_ADD(flags, RSA_OPT_ENC_INFO_ONLY);
		is_encryption_info_only = 1;
		break;
	case RSA_OPT_ORIG_FILE:
		OPT_ADD(flags, RSA_OPT_ORIG_FILE);
		keep_orig_file = 1;
		break;
	default:
		rsa_error_message(RSA_ERR_OPTARG);
		return -1;
	}

	return 0;
}

int main(int argc, char *argv[])
{
	int ret, action;
	unsigned int flags = 0;
	rsa_handler_t decrypter_handler = {
		.keytype = RSA_KEY_TYPE_PRIVATE,
		.options = options_decrypter,
		.ops_handler = parse_args_decrypter,
		.ops_handler_finalize = parse_args_finalize_decrypter,
	};

	if (parse_args(argc, argv, &flags, &decrypter_handler))
		return rsa_error(argv[0]);

	action = rsa_action_get(flags, RSA_OPT_DECRYPT, RSA_OPT_KEYGEN, NULL);
	switch (action)
	{
	case OPT_FLAG(RSA_OPT_KEYGEN):
		ret = rsa_keygen();
		break;
	case OPT_FLAG(RSA_OPT_DECRYPT):
		ret = rsa_decrypt();
		break;
	default:
		ret = rsa_action_handle_common(action, argv[0],
			&decrypter_handler);
		break;
	}

	return ret;
}