/* See LICENSE file for copyright and license details. */
#include <stdio.h>
#include <stdlib.h>
#include <stdint.h>
#include <string.h>
#include "../util.h"
#include "../text.h"
#include "../crypt.h"

static int
hexdec(int c) {
	if(c >= '0' && c <= '9')
		return c - '0';
	else if(c >= 'A' && c <= 'F')
		return c - 'A' + 10;
	else if(c >= 'a' && c <= 'f')
		return c - 'a' + 10;
	return -1; /* unknown character */
}

static int
mdcheckline(const char *s, uint8_t *md, size_t sz) {
	size_t i;
	int b1, b2;

	for(i = 0; i < sz; i++) {
		if(!*s || (b1 = hexdec(*s++)) < 0)
			return -1; /* invalid format */
		if(!*s || (b2 = hexdec(*s++)) < 0)
			return -1; /* invalid format */
		if((uint8_t)((b1 << 4) | b2) != md[i])
			return 0; /* value mismatch */
	}
	return (i == sz) ? 1 : 0;
}

int
cryptcheck(char *sumfile, int argc, char *argv[],
	  struct crypt_ops *ops, uint8_t *md, size_t sz)
{
	FILE *cfp, *fp;
	char *line = NULL, *file, *p;
	int r, nonmatch = 0, formatsucks = 0, noread = 0, ret = EXIT_SUCCESS;
	size_t bufsiz = 0;

	if(!(cfp = fopen(sumfile, "r")))
		eprintf("fopen %s:", sumfile);

	while(afgets(&line, &bufsiz, cfp)) {
		if(!(file = strstr(line, "  "))) {
			formatsucks++;
			continue;
		}
		if((file - line) / 2 != sz) {
			formatsucks++; /* checksum length mismatch */
			continue;
		}
		*file = '\0';
		file += 2;
		for(p = file; *p && *p != '\n' && *p != '\r'; p++); /* strip newline */
		*p = '\0';
		if(!(fp = fopen(file, "r"))) {
			weprintf("fopen %s:", file);
			noread++;
			continue;
		}
		cryptsum(ops, fp, file, md);
		r = mdcheckline(line, md, sz);
		if(r == 1) {
			printf("%s: OK\n", file);
		} else if(r == 0) {
			printf("%s: FAILED\n", file);
			nonmatch++;
		} else {
			formatsucks++;
		}
		fclose(fp);
	}
	fclose(cfp);
	free(line);
	if(formatsucks > 0) {
		weprintf("WARNING: %d lines are improperly formatted\n", formatsucks);
		ret = EXIT_FAILURE;
	}
	if(noread > 0) {
		weprintf("WARNING: %d listed file could not be read\n", noread);
		ret = EXIT_FAILURE;
	}
	if(nonmatch > 0) {
		weprintf("WARNING: %d computed checksums did NOT match\n", nonmatch);
		ret = EXIT_FAILURE;
	}
	return ret;
}

int
cryptmain(int argc, char *argv[],
	  struct crypt_ops *ops, uint8_t *md, size_t sz)
{
	FILE *fp;
	int ret = EXIT_SUCCESS;

	if (argc == 0) {
		cryptsum(ops, stdin, "<stdin>", md);
		mdprint(md, "<stdin>", sz);
	} else {
		for (; argc > 0; argc--) {
			if((fp = fopen(*argv, "r")) == NULL) {
				weprintf("fopen %s:", *argv);
				ret = EXIT_FAILURE;
				continue;
			}
			if(cryptsum(ops, fp, *argv, md) == 1)
				ret = EXIT_FAILURE;
			else
				mdprint(md, *argv, sz);
			fclose(fp);
			argv++;
		}
	}
	return ret;
}

int
cryptsum(struct crypt_ops *ops, FILE *fp, const char *f,
	 uint8_t *md)
{
	uint8_t buf[BUFSIZ];
	size_t n;

	ops->init(ops->s);
	while ((n = fread(buf, 1, sizeof(buf), fp)) > 0)
		ops->update(ops->s, buf, n);
	if (ferror(fp)) {
		weprintf("read error: %s:", f);
		return 1;
	}
	ops->sum(ops->s, md);
	return 0;
}

void
mdprint(const uint8_t *md, const char *f, size_t len)
{
	size_t i;

	for (i = 0; i < len; i++)
		printf("%02x", md[i]);
	printf("  %s\n", f);
}