rsa_main.c

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

static opt_t options_master[] = {
	{RSA_OPT_FILE, 'f', "file", required_argument, ARG " is the input file "
		"to encrypt/decrypt"},
	{RSA_OPT_ENCRYPT, 'e', "encrypt", no_argument, "encrypt the data file "
		"stated by --file"},
	{RSA_OPT_LEVEL, 'l', "level", required_argument, "set encryption level "
		"to 128(default), 256, 512 or 1024. this switch implies "
		"encryption"},
	{RSA_OPT_RSAENC, 'r', "rsa", no_argument, "full RSA encryption. if "
		"this flag is not set, encryption will be done by xoring the "
		"plaintext with a sequence generated by a pseudo random number "
		"generator (RNG). the seed of the sequence will be randomly "
		"generated and only it will be RSA encrypted. this switch "
		"implies encryption"},
	{RSA_OPT_CBC, 'c', "cbc", no_argument, "full RSA encryption using "
		"Cipher Block Chaining (CBC) cipher mode. by default "
		"Electronic Codebook (ECB) is used"},
	{RSA_OPT_KEY_SET_DYNAMIC, 'k', "key", required_argument, "set the RSA "
		"key to be used for the current encryption. this options "
		"overrides the default key if it has been set. this switch "
		"implies encryption"},
	{RSA_OPT_DECRYPT, 'd', "decrypt", no_argument, "decrypt the encrypted "
		"file stated by --file"},
	{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 encrypted/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_master(unsigned int *flags, int actions)
{
	/* RSA_OPT_CBC implies RSA_OPT_RSAENC */
	if (*flags & (OPT_FLAG(RSA_OPT_CBC)))
		*flags |= OPT_FLAG(RSA_OPT_RSAENC);

	/* RSA_OPT_LEVEL, RSA_OPT_RSAENC and RSA_OPT_KEY_SET_DYNAMIC imply
	 * RSA_OPT_ENCRYPT */
	if (*flags & (OPT_FLAG(RSA_OPT_LEVEL) | OPT_FLAG(RSA_OPT_RSAENC) |
		OPT_FLAG(RSA_OPT_KEY_SET_DYNAMIC))) {
		*flags |= OPT_FLAG(RSA_OPT_ENCRYPT);
	}

	if (*flags & (OPT_FLAG(RSA_OPT_ENC_INFO_ONLY)))
		*flags |= OPT_FLAG(RSA_OPT_DECRYPT);

	if (*flags & OPT_FLAG(RSA_OPT_ENCRYPT))
		actions++;
	if (*flags & OPT_FLAG(RSA_OPT_DECRYPT))
		actions++;
	if (*flags & OPT_FLAG(RSA_OPT_KEYGEN))
		actions++;

	/* test for a single action option */
	if (actions != 1) {
		rsa_error_message(actions ?
			RSA_ERR_MULTIACTION : RSA_ERR_NOACTION);
		return -1;
	}
	/* test for non compatible options with encrypt/decrypt */
	else if ((*flags & (OPT_FLAG(RSA_OPT_ENCRYPT) |
		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_master(int opt, unsigned int *flags)
{
	switch (opt_short2code(options_master, opt))
	{
	case RSA_OPT_FILE:
		OPT_ADD(flags, RSA_OPT_FILE);
		if (rsa_set_file_name(optarg))
			return -1;
		break;
	case RSA_OPT_ENCRYPT:
		OPT_ADD(flags, RSA_OPT_ENCRYPT);
		break;
	case RSA_OPT_LEVEL:
		OPT_ADD(flags, RSA_OPT_LEVEL);
		if (rsa_encryption_level_set(optarg))
			return -1;
		break;
	case RSA_OPT_RSAENC:
		OPT_ADD(flags, RSA_OPT_RSAENC);
		break;
	case RSA_OPT_CBC:
		OPT_ADD(flags, RSA_OPT_CBC);
		cipher_mode = CIPHER_MODE_CBC;
		break;
	case RSA_OPT_KEY_SET_DYNAMIC:
		OPT_ADD(flags, RSA_OPT_KEY_SET_DYNAMIC);
		if (optarg && rsa_set_key_name(optarg))
			return -1;
		break;
	case RSA_OPT_DECRYPT:
		OPT_ADD(flags, RSA_OPT_DECRYPT);
		break;
	case RSA_OPT_ORIG_FILE:
		OPT_ADD(flags, RSA_OPT_ORIG_FILE);
		keep_orig_file = 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;
	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 master_handler = {
		.keytype = RSA_KEY_TYPE_PUBLIC | RSA_KEY_TYPE_PRIVATE,
		.options = options_master,
		.ops_handler = parse_args_master,
		.ops_handler_finalize = parse_args_finalize_master,
	};

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

	action = rsa_action_get(flags, RSA_OPT_ENCRYPT, RSA_OPT_DECRYPT,
		RSA_OPT_KEYGEN, NULL);
	switch (action)
	{
	case OPT_FLAG(RSA_OPT_ENCRYPT):
		{
			if (!(flags & OPT_FLAG(RSA_OPT_LEVEL)))
				rsa_encryption_level_set(NULL);

			ret = flags & OPT_FLAG(RSA_OPT_RSAENC) ?
				rsa_encrypt_full() : rsa_encrypt_quick();
			break;
		}
	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],
			&master_handler);
		break;
	}

	return ret;
}