/*
	apachedbm.c
	(c) 1999 Mrs. Brisby <mrs.brisby@nimh.org>

	a dbmmanage replacement.

	dbmmanage is a tool supplied with Apache that modifies DBM databases.
	However, unless PERL and Apache are built to use the same DBM library
	(which can be trying) dbmmanage will not function properly AT ALL!

	This works with almost the exact same syntax, and operates using the
	same DBM api that Apache uses (e.g. the NDBM api).

	I've noticed no problems with this program. If you do, by all means
	let me know (patches also welcome).

	Compile using:
		cc -o apachedbm apachedbm.c -ldbm
	
	If you have an external crypt library:
		cc -o apachedbm apachedbm.c -ldbm -lcrypt
	
	If you want this to work with NETSCAPE's dbm files/server, you can add
		cc -DNETSCAPE_DBM_COMPAT -o apachedbm apachedbm.c -ldbm

	4.4BSD derived systems (BSD/OS 2.0) may or may not support longer
	crypt results, and bigger salts. Support for this can be enabled using:
		cc -DNEWSTYLE_CRYPT -o apachedbm apachedbm.c -ldbm

	In general: The same CFLAGS and libraries used to build apache should
	function well here. If you use GDBM for apache, specify -lgdbm instead
	of -ldbm. Look in your .../apache/src/Configuration for the proper
	flags.
*/
#include <ndbm.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <stdio.h>
#include <string.h>
#include <unistd.h>
#include <fcntl.h>

enum {
	ADBM_ADD,
	ADBM_ADDUSER,
	ADBM_CHECK,
	ADBM_DELETE,
	ADBM_IMPORT,
	ADBM_UPDATE,
	ADBM_VIEW
};

static char randchar(void)
{
	int i;
	char *rmap = "./0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ";

	i = rand() % strlen(rmap);
	return rmap[i];
}
static char *gensalt(void)
{
#ifdef NEWSTYLE_CRYPT
	static char salt[10];
	salt[0] = '_';
	salt[1] = randchar();
	salt[2] = 'a';
	salt[3] = '.';
	salt[4] = '.';
	salt[5] = randchar();
	salt[6] = randchar();
	salt[7] = randchar();
	salt[8] = randchar();
	salt[9] = '\0';
#else
	static char salt[3];
	salt[0] = randchar();
	salt[1] = randchar();
	salt[2] = '\0';
#endif
	return salt;
}

int main(int argc, char *argv[])
{
#define USAGE \
printf("usage: %s filename [add|adduser|check|delete|import|update|view] [username]\n", argv[0]); exit(0);

	DBM *f;
	datum d, q;
	char *filename;
	char *ip, *ap;
	char buf[256];
	int command;

	if (argc < 3) { USAGE }

	filename = argv[1];
	if (strcasecmp(argv[2], "adduser") == 0) {
		command = ADBM_ADDUSER;
	} else
	switch (*(argv[2])) {
	case 'a': case 'A': command = ADBM_ADD; break;
	case 'c': case 'C': command = ADBM_CHECK; break;
	case 'd': case 'D': command = ADBM_DELETE; break;
	case 'i': case 'I': command = ADBM_IMPORT; break;
	case 'u': case 'U': command = ADBM_UPDATE; break;
	case 'v': case 'V': command = ADBM_VIEW; break;
	default: USAGE
	};

	if (command != ADBM_IMPORT && command != ADBM_CHECK && command != ADBM_VIEW) {
		if (argc < 4) { USAGE }
		q.dptr = argv[3];
#ifndef NETSCAPE_DBM_COMPAT
		q.dsize = strlen(q.dptr);
#else
		q.dsize = strlen(q.dptr)+1;
#endif
	}

	if (!(f = dbm_open(filename, O_RDWR|O_CREAT, 0644))) {
		perror("dbm_open");
		exit(1);
	}

	if (command == ADBM_VIEW) {
		q = dbm_firstkey(f);
		while (q.dptr) {
			d = dbm_fetch(f, q);

			fwrite(q.dptr, q.dsize, 1, stdout);
			fputc(':', stdout);
			fwrite(d.dptr, d.dsize, 1, stdout);
			fputc('\n', stdout);

			q = dbm_nextkey(f);
		}
		dbm_close(f);
		exit(0);
	}
	if (command == ADBM_IMPORT) {
		while (fgets(buf, 255, stdin)) {
			ap = strchr(buf, '\r');
			if (ap) { *ap = 0; }

			ap = strchr(buf, '\n');
			if (ap) { *ap = 0; }

			ap = strchr(buf, ':');
			if (ap) {
				*ap = 0;
				ap++;
			} else
				ap = "";

			q.dptr = ip;
#ifndef NETSCAPE_DBM_COMPAT
			q.dsize = strlen(ip);
#else
			q.dsize = strlen(ip)+1;
#endif

			d.dptr = ap;
			d.dsize = strlen(ap);

			(void) dbm_store(f, q, d, DBM_REPLACE);
		}
		dbm_close(f);
		exit(0);
	}

	if (command == ADBM_DELETE) {
		if (dbm_delete(f, q) == -1) {
			printf("Sorry, user `%s' doesn't exist!\n", argv[3]);
			dbm_close(f);
			exit(1);
		}
		dbm_close(f);
		exit(0);
	}
	if (command == ADBM_CHECK) {
		d = dbm_fetch(f, q);
		if (!d.dptr) {
			printf("Sorry, user `%s' doesn't exist!\n", argv[3]);
			dbm_close(f);
			exit(1);
		}
		ip = getpass("Password: ");
		ap = (char *)crypt(ip, d.dptr);
		if (d.dsize == strlen(ap) && strncmp(ap, d.dptr, d.dsize) == 0)
			puts("password ok");
		else
			puts("password mismatch");
		dbm_close(f);
		exit(0);
	}
	if (command == ADBM_ADD || command == ADBM_ADDUSER || command == ADBM_UPDATE) {
		ip = getpass("New password: ");
		ap = getpass("Re-type new password: ");
		if (strcmp(ip, ap) != 0) {
			puts("They don't match, sorry.");
			dbm_close(f);
			exit(1);
		}
		if (ADBM_ADD)
			ap = ip;
		else {
			srand(time(0));
			ap = (char *)crypt(ip, gensalt());
		}
		d.dptr = ap;
		d.dsize = strlen(ap);
		if (-1 == dbm_store(f, q, d, 
			(command==ADBM_UPDATE)?DBM_REPLACE:DBM_INSERT)) {

			if (command = ADBM_UPDATE)
				printf("Sorry, user `%s' doesn't exist!\n", argv[3]);
			else
				printf("Sorry, user `%s' already exists!\n", argv[3]);
			dbm_close(f);
			exit(1);
		}
		/* done */
		dbm_close(f);
		exit(0);
	}
	dbm_close(f);
	return 0; /* should never reach */
}