text: /*-
   * Copyright 2009 Colin Percival
   * All rights reserved.
   *
   * Redistribution and use in source and binary forms, with or without
   * modification, are permitted provided that the following conditions
   * are met:
   * 1. Redistributions of source code must retain the above copyright
   *    notice, this list of conditions and the following disclaimer.
   * 2. Redistributions in binary form must reproduce the above copyright
   *    notice, this list of conditions and the following disclaimer in the
   *    documentation and/or other materials provided with the distribution.
   *
   * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
   * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
   * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
   * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
   * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
   * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
   * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
   * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
   * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
   * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
   * SUCH DAMAGE.
   */
  #include "scrypt_platform.h"
  
  #include <math.h>
  #include <stdint.h>
  #include <stdio.h>
  #include <stdlib.h>
  #include <string.h>
  
  #include "getopt.h"
  #include "humansize.h"
  #include "insecure_memzero.h"
  #include "parsenum.h"
  #include "readpass.h"
  #include "scryptenc.h"
  #include "warnp.h"
  
  static void
  usage(void)
  {
  
  	fprintf(stderr,
  	    "usage: scrypt {enc | dec} [-f] [-M maxmem]"
  	    " [-m maxmemfrac]\n"
  	    "              [-t maxtime] [-v] [-P] infile [outfile]\n"
  	    "       scrypt --version\n");
  	exit(1);
  }
  
  int
  main(int argc, char *argv[])
  {
  	FILE * infile;
  	FILE * outfile = stdout;
  	int devtty = 1;
  	int dec = 0;
  	size_t maxmem = 0;
  	int force_resources = 0;
  	uint64_t maxmem64;
  	double maxmemfrac = 0.5;
  	double maxtime = 300.0;
  	const char * ch;
  	const char * infilename;
  	const char * outfilename;
  	char * passwd;
  	int rc;
  	int verbose = 0;
  	struct scryptdec_file_cookie * C = NULL;
  
  	WARNP_INIT;
  
  	/* We should have "enc" or "dec" first. */
  	if (argc < 2)
  		usage();
  	if (strcmp(argv[1], "enc") == 0) {
  		maxmem = 0;
  		maxmemfrac = 0.125;
  		maxtime = 5.0;
  	} else if (strcmp(argv[1], "dec") == 0) {
  		dec = 1;
  	} else if (strcmp(argv[1], "--version") == 0) {
  		fprintf(stdout, "scrypt %s\n", PACKAGE_VERSION);
  		exit(0);
  	} else {
  		warn0("First argument must be 'enc' or 'dec'.\n");
  		usage();
  	}
  	argc--;
  	argv++;
  
  	/* Parse arguments. */
  	while ((ch = GETOPT(argc, argv)) != NULL) {
  		GETOPT_SWITCH(ch) {
  		GETOPT_OPT("-f"):
  			force_resources = 1;
  			break;
  		GETOPT_OPTARG("-M"):
  			if (humansize_parse(optarg, &maxmem64)) {
  				warn0("Could not parse the parameter to -M.");
  				exit(1);
  			}
  			if (maxmem64 > SIZE_MAX) {
  				warn0("The parameter to -M is too large.");
  				exit(1);
  			}
  			maxmem = (size_t)maxmem64;
  			break;
  		GETOPT_OPTARG("-m"):
  			if (PARSENUM(&maxmemfrac, optarg, 0, 1)) {
  				warnp("Invalid option: -m %s", optarg);
  				exit(1);
  			}
  			break;
  		GETOPT_OPTARG("-t"):
  			if (PARSENUM(&maxtime, optarg, 0, INFINITY)) {
  				warnp("Invalid option: -t %s", optarg);
  				exit(1);
  			}
  			break;
  		GETOPT_OPT("-v"):
  			verbose = 1;
  			break;
  		GETOPT_OPT("-P"):
  			devtty = 0;
  			break;
  		GETOPT_MISSING_ARG:
  			warn0("Missing argument to %s\n", ch);
  			usage();
  		GETOPT_DEFAULT:
  			warn0("illegal option -- %s\n", ch);
  			usage();
  		}
  	}
  	argc -= optind;
  	argv += optind;
  
  	/* We must have one or two parameters left. */
  	if ((argc < 1) || (argc > 2))
  		usage();
  
  	/* Set the input filename. */
  	if (strcmp(argv[0], "-"))
  		infilename = argv[0];
  	else
  		infilename = NULL;
  
  	/* Set the output filename. */
  	if (argc > 1)
  		outfilename = argv[1];
  	else
  		outfilename = NULL;
  
  	/* If the input isn't stdin, open the file. */
  	if (infilename != NULL) {
  		if ((infile = fopen(infilename, "rb")) == NULL) {
  			warnp("Cannot open input file: %s", infilename);
  			goto err0;
  		}
  	} else {
  		infile = stdin;
  	}
  
  	/* Prompt for a password. */
  	if (readpass(&passwd, "Please enter passphrase",
  	    (dec || !devtty) ? NULL : "Please confirm passphrase", devtty))
  		goto err1;
  
  	/*-
  	 * If we're decrypting, open the input file and process its header;
  	 * doing this here allows us to abort without creating an output
  	 * file if the input file does not have a valid scrypt header or if
  	 * we have the wrong passphrase.
  	 *
  	 * If successful, we get back a cookie containing the decryption
  	 * parameters (which we'll use after we open the output file).
  	 */
  	if (dec) {
  		if ((rc = scryptdec_file_prep(infile, (uint8_t *)passwd,
  		    strlen(passwd), maxmem, maxmemfrac, maxtime, verbose,
  		    force_resources, &C)) != 0) {
  			goto cleanup;
  		}
  	}
  
  	/* If we have an output file, open it. */
  	if (outfilename != NULL) {
  		if ((outfile = fopen(outfilename, "wb")) == NULL) {
  			warnp("Cannot open output file: %s", outfilename);
  			goto err2;
  		}
  	}
  
  	/* Encrypt or decrypt. */
  	if (dec)
  		rc = scryptdec_file_copy(C, outfile);
  	else
  		rc = scryptenc_file(infile, outfile, (uint8_t *)passwd,
  		    strlen(passwd), maxmem, maxmemfrac, maxtime, verbose);
  
  cleanup:
  	/* Free the decryption cookie, if any. */
  	scryptdec_file_cookie_free(C);
  
  	/* Zero and free the password. */
  	insecure_memzero(passwd, strlen(passwd));
  	free(passwd);
  
  	/* Close any files we opened. */
  	if (infile != stdin)
  		fclose(infile);
  	if (outfile != stdout)
  		fclose(outfile);
  
  	/* If we failed, print the right error message and exit. */
  	if (rc != 0) {
  		switch (rc) {
  		case 1:
  			warnp("Error determining amount of available memory");
  			break;
  		case 2:
  			warnp("Error reading clocks");
  			break;
  		case 3:
  			warnp("Error computing derived key");
  			break;
  		case 4:
  			warnp("Error reading salt");
  			break;
  		case 5:
  			warnp("OpenSSL error");
  			break;
  		case 6:
  			warnp("Error allocating memory");
  			break;
  		case 7:
  			warn0("Input is not valid scrypt-encrypted block");
  			break;
  		case 8:
  			warn0("Unrecognized scrypt format version");
  			break;
  		case 9:
  			warn0("Decrypting file would require too much memory");
  			break;
  		case 10:
  			warn0("Decrypting file would take too much CPU time");
  			break;
  		case 11:
  			warn0("Passphrase is incorrect");
  			break;
  		case 12:
  			warnp("Error writing file: %s",
  			    (outfilename != NULL) ? outfilename
  			    : "standard output");
  			break;
  		case 13:
  			warnp("Error reading file: %s",
  			    (infilename != NULL) ? infilename
  			    : "standard input");
  			break;
  		}
  		goto err0;
  	}
  
  	/* Success! */
  	return (0);
  
  err2:
  	scryptdec_file_cookie_free(C);
  	insecure_memzero(passwd, strlen(passwd));
  	free(passwd);
  err1:
  	if (infile != stdin)
  		fclose(infile);
  err0:
  	/* Failure! */
  	exit(1);
  }
  