/* apps/passwd.c */

#if defined NO_MD5 || defined CHARSET_EBCDIC
# define NO_APR1
#endif

#if !defined(NO_DES) || !defined(NO_APR1)

#include <assert.h>
#include <string.h>

#include "apps.h"

#include <openssl/bio.h>
#include <openssl/err.h>
#include <openssl/evp.h>
#include <openssl/rand.h>

#ifndef NO_DES
# include <openssl/des.h>
#endif
#ifndef NO_APR1
# include <openssl/md5.h>
#endif


#undef PROG
#define PROG passwd_main


static unsigned const char cov_2char[64]={
	/* from crypto/des/fcrypt.c */
	0x2E,0x2F,0x30,0x31,0x32,0x33,0x34,0x35,
	0x36,0x37,0x38,0x39,0x41,0x42,0x43,0x44,
	0x45,0x46,0x47,0x48,0x49,0x4A,0x4B,0x4C,
	0x4D,0x4E,0x4F,0x50,0x51,0x52,0x53,0x54,
	0x55,0x56,0x57,0x58,0x59,0x5A,0x61,0x62,
	0x63,0x64,0x65,0x66,0x67,0x68,0x69,0x6A,
	0x6B,0x6C,0x6D,0x6E,0x6F,0x70,0x71,0x72,
	0x73,0x74,0x75,0x76,0x77,0x78,0x79,0x7A
};

static int do_passwd(int passed_salt, char **salt_p, char **salt_malloc_p,
	char *passwd, BIO *out, int quiet, int table, int reverse,
	size_t pw_maxlen, int usecrypt, int useapr1);

/* -crypt        - standard Unix password algorithm (default, only choice)
 * -apr1         - MD5-based password algorithm
 * -salt string  - salt
 * -in file      - read passwords from file
 * -stdin        - read passwords from stdin
 * -quiet        - no warnings
 * -table        - format output as table
 * -reverse      - switch table columns
 */

int MAIN(int, char **);

int MAIN(int argc, char **argv)
	{
	int ret = 1;
	char *infile = NULL;
	int in_stdin = 0;
	char *salt = NULL, *passwd = NULL, **passwds = NULL;
	char *salt_malloc = NULL, *passwd_malloc = NULL;
	int pw_source_defined = 0;
	BIO *in = NULL, *out = NULL;
	int i, badopt, opt_done;
	int passed_salt = 0, quiet = 0, table = 0, reverse = 0;
	int usecrypt = 0, useapr1 = 0;
	size_t pw_maxlen = 0;

	apps_startup();

	if (bio_err == NULL)
		if ((bio_err=BIO_new(BIO_s_file())) != NULL)
			BIO_set_fp(bio_err,stderr,BIO_NOCLOSE|BIO_FP_TEXT);
	out = BIO_new(BIO_s_file());
	if (out == NULL)
		goto err;
	BIO_set_fp(out, stdout, BIO_NOCLOSE | BIO_FP_TEXT);

	badopt = 0, opt_done = 0;
	i = 0;
	while (!badopt && !opt_done && argv[++i] != NULL)
		{
		if (strcmp(argv[i], "-crypt") == 0)
			usecrypt = 1;
		else if (strcmp(argv[i], "-apr1") == 0)
			useapr1 = 1;
		else if (strcmp(argv[i], "-salt") == 0)
			{
			if ((argv[i+1] != NULL) && (salt == NULL))
				{
				passed_salt = 1;
				salt = argv[++i];
				}
			else
				badopt = 1;
			}
		else if (strcmp(argv[i], "-in") == 0)
			{
			if ((argv[i+1] != NULL) && !pw_source_defined)
				{
				pw_source_defined = 1;
				infile = argv[++i];
				}
			else
				badopt = 1;
			}
		else if (strcmp(argv[i], "-stdin") == 0)
			{
			if (!pw_source_defined)
				{
				pw_source_defined = 1;
				in_stdin = 1;
				}
			else
				badopt = 1;
			}
		else if (strcmp(argv[i], "-quiet") == 0)
			quiet = 1;
		else if (strcmp(argv[i], "-table") == 0)
			table = 1;
		else if (strcmp(argv[i], "-reverse") == 0)
			reverse = 1;
		else if (argv[i][0] == '-')
			badopt = 1;
		else if (!pw_source_defined)
			/* non-option arguments, use as passwords */
			{
			pw_source_defined = 1;
			passwds = &argv[i];
			opt_done = 1;
			}
		else
			badopt = 1;
		}

	if (!usecrypt && !useapr1) /* use default */
		usecrypt = 1;
	if (usecrypt + useapr1 > 1) /* conflict */
		badopt = 1;

	/* reject unsupported algorithms */
#ifdef NO_DES
	if (usecrypt) badopt = 1;
#endif
#ifdef NO_APR1
	if (useapr1) badopt = 1;
#endif

	if (badopt) 
		{
		BIO_printf(bio_err, "Usage: passwd [options] [passwords]\n");
		BIO_printf(bio_err, "where options are\n");
#ifndef NO_DES
		BIO_printf(bio_err, "-crypt             standard Unix password algorithm (default)\n");
#endif
#ifndef NO_APR1
		BIO_printf(bio_err, "-apr1              MD5-based password algorithm\n");
#endif
		BIO_printf(bio_err, "-salt string       use provided salt\n");
		BIO_printf(bio_err, "-in file           read passwords from file\n");
		BIO_printf(bio_err, "-stdin             read passwords from stdin\n");
		BIO_printf(bio_err, "-quiet             no warnings\n");
		BIO_printf(bio_err, "-table             format output as table\n");
		BIO_printf(bio_err, "-reverse           switch table columns\n");
		
		goto err;
		}

	if ((infile != NULL) || in_stdin)
		{
		in = BIO_new(BIO_s_file());
		if (in == NULL)
			goto err;
		if (infile != NULL)
			{
			assert(in_stdin == 0);
			if (BIO_read_filename(in, infile) <= 0)
				goto err;
			}
		else
			{
			assert(in_stdin);
			BIO_set_fp(in, stdin, BIO_NOCLOSE);
			}
		}
	
	if (usecrypt)
		pw_maxlen = 8;
	else if (useapr1)
		pw_maxlen = 256; /* arbitrary limit, should be enough for most passwords */

	if (passwds == NULL)
		{
		/* no passwords on the command line */
#define PASSWD_MALLOC_SIZE (pw_maxlen + 2)
		/* longer than necessary so that we can warn about truncation */
		passwd = passwd_malloc = Malloc(PASSWD_MALLOC_SIZE);
		if (passwd_malloc == NULL)
			goto err;
		}

	if ((in == NULL) && (passwds == NULL))
		{
		/* build a null-terminated list */
		static char *passwds_static[2] = {NULL, NULL};
		
		passwds = passwds_static;
		if (in == NULL)
			if (EVP_read_pw_string(passwd_malloc, PASSWD_MALLOC_SIZE, "Password: ", 0) != 0)
				goto err;
		passwds[0] = passwd_malloc;
		}

	if (in == NULL)
		{
		assert(passwds != NULL);
		assert(*passwds != NULL);
		
		do /* loop over list of passwords */
			{
			passwd = *passwds++;
			if (!do_passwd(passed_salt, &salt, &salt_malloc, passwd, out,
				quiet, table, reverse, pw_maxlen, usecrypt, useapr1))
				goto err;
			}
		while (*passwds != NULL);
		}
	else
		/* in != NULL */
		{
		int done;

		assert (passwd != NULL);
		do
			{
			int r = BIO_gets(in, passwd, pw_maxlen + 1);
			if (r > 0)
				{
				char *c = (strchr(passwd, '\n')) ;
				if (c != NULL)
					*c = 0; /* truncate at newline */
				else
					{
					/* ignore rest of line */
					char trash[BUFSIZ];
					do
						r = BIO_gets(in, trash, sizeof trash);
					while ((r > 0) && (!strchr(trash, '\n')));
					}
				
				if (!do_passwd(passed_salt, &salt, &salt_malloc, passwd, out,
					quiet, table, reverse, pw_maxlen, usecrypt, useapr1))
					goto err;
				}
			done = (r <= 0);
			}
		while (!done);
		}

err:
	ERR_print_errors(bio_err);
	if (salt_malloc)
		Free(salt_malloc);
	if (passwd_malloc)
		Free(passwd_malloc);
	if (in)
		BIO_free(in);
	if (out)
		BIO_free(out);
	EXIT(ret);
	}


#ifndef NO_APR1
/* MD5-based password algorithm compatible to the one found in Apache
 * (should probably be available as a library function;
 * then the static buffer would not be acceptable) */
static char *apr1_crypt(const char *passwd, const char *salt)
	{
	static char out_buf[6 + 9 + 24 + 2]; /* "$apr1$..salt..$.......md5hash..........\0" */
	unsigned char buf[MD5_DIGEST_LENGTH];
	char *salt_out;
	int n, i;
	MD5_CTX md;
	size_t passwd_len, salt_len;

	passwd_len = strlen(passwd);
	strcpy(out_buf, "$apr1$");
	strncat(out_buf, salt, 8);
	assert(strlen(out_buf) <= 6 + 8); /* "$apr1$..salt.." */
	salt_out = out_buf + 6;
	salt_len = strlen(salt_out);
	assert(salt_len <= 8);
	
	MD5_Init(&md);
	MD5_Update(&md, passwd, passwd_len);
	MD5_Update(&md, "$apr1$", 6);
	MD5_Update(&md, salt_out, salt_len);
	
	 {
		MD5_CTX md2;

		MD5_Init(&md2);
		MD5_Update(&md2, passwd, passwd_len);
		MD5_Update(&md2, salt_out, salt_len);
		MD5_Update(&md2, passwd, passwd_len);
		MD5_Final(buf, &md2);
	 }
	for (i = passwd_len; i > sizeof buf; i -= sizeof buf)
		MD5_Update(&md, buf, sizeof buf);
	MD5_Update(&md, buf, i);
	
	n = passwd_len;
	while (n)
		{
		MD5_Update(&md, (n & 1) ? "\0" : passwd, 1);
		n >>= 1;
		}
	MD5_Final(buf, &md);

	for (i = 0; i < 1000; i++)
		{
		MD5_CTX md2;

		MD5_Init(&md2);
		MD5_Update(&md2, (i & 1) ? (unsigned char *) passwd : buf,
		                 (i & 1) ? passwd_len : sizeof buf);
		if (i % 3)
			MD5_Update(&md2, salt_out, salt_len);
		if (i % 7)
			MD5_Update(&md2, passwd, passwd_len);
		MD5_Update(&md2, (i & 1) ? buf : (unsigned char *) passwd,
		                 (i & 1) ? sizeof buf : passwd_len);
		MD5_Final(buf, &md2);
		}
	
	 {
		/* transform buf into output string */
	
		unsigned char buf_perm[sizeof buf];
		int dest, source;
		char *output;

		/* silly output permutation */
		for (dest = 0, source = 0; dest < 14; dest++, source = (source + 6) % 17)
			buf_perm[dest] = buf[source];
		buf_perm[14] = buf[5];
		buf_perm[15] = buf[11];
#ifndef PEDANTIC /* Unfortunately, this generates a "no effect" warning */
		assert(16 == sizeof buf_perm);
#endif
		
		output = salt_out + salt_len;
		assert(output == out_buf + strlen(out_buf));
		
		*output++ = '$';

		for (i = 0; i < 15; i += 3)
			{
			*output++ = cov_2char[buf_perm[i+2] & 0x3f];
			*output++ = cov_2char[((buf_perm[i+1] & 0xf) << 2) |
				                  (buf_perm[i+2] >> 6)];
			*output++ = cov_2char[((buf_perm[i] & 3) << 4) |
				                  (buf_perm[i+1] >> 4)];
			*output++ = cov_2char[buf_perm[i] >> 2];
			}
		assert(i == 15);
		*output++ = cov_2char[buf_perm[i] & 0x3f];
		*output++ = cov_2char[buf_perm[i] >> 6];
		*output = 0;
		assert(strlen(out_buf) < sizeof(out_buf));
	 }

	return out_buf;
	}
#endif


static int do_passwd(int passed_salt, char **salt_p, char **salt_malloc_p,
	char *passwd, BIO *out,	int quiet, int table, int reverse,
	size_t pw_maxlen, int usecrypt, int useapr1)
	{
	char *hash = NULL;

	assert(salt_p != NULL);
	assert(salt_malloc_p != NULL);

	/* first make sure we have a salt */
	if (!passed_salt)
		{
#ifndef NO_DES
		if (usecrypt)
			{
			if (*salt_malloc_p == NULL)
				{
				*salt_p = *salt_malloc_p = Malloc(3);
				if (*salt_malloc_p == NULL)
					goto err;
				}
			if (RAND_pseudo_bytes((unsigned char *)*salt_p, 2) < 0)
				goto err;
			(*salt_p)[0] = cov_2char[(*salt_p)[0] & 0x3f]; /* 6 bits */
			(*salt_p)[1] = cov_2char[(*salt_p)[1] & 0x3f]; /* 6 bits */
			(*salt_p)[2] = 0;
#ifdef CHARSET_EBCDIC
			ascii2ebcdic(*salt_p, *salt_p, 2); /* des_crypt will convert
			                                    * back to ASCII */
#endif
			}
#endif /* !NO_DES */

#ifndef NO_APR1
		if (useapr1)
			{
			int i;
			
			if (*salt_malloc_p == NULL)
				{
				*salt_p = *salt_malloc_p = Malloc(9);
				if (*salt_malloc_p == NULL)
					goto err;
				}
			if (RAND_pseudo_bytes((unsigned char *)*salt_p, 8) < 0)
				goto err;
			
			for (i = 0; i < 8; i++)
				(*salt_p)[i] = cov_2char[(*salt_p)[i] & 0x3f]; /* 6 bits */
			(*salt_p)[8] = 0;
			}
#endif /* !NO_APR1 */
		}
	
	assert(*salt_p != NULL);
	
	/* truncate password if necessary */
	if ((strlen(passwd) > pw_maxlen))
		{
		if (!quiet)
			BIO_printf(bio_err, "Warning: truncating password to %u characters\n", pw_maxlen);
		passwd[pw_maxlen] = 0;
		}
	assert(strlen(passwd) <= pw_maxlen);
	
	/* now compute password hash */
#ifndef NO_DES
	if (usecrypt)
		hash = des_crypt(passwd, *salt_p);
#endif
#ifndef NO_APR1
	if (useapr1)
		hash = apr1_crypt(passwd, *salt_p);
#endif
	assert(hash != NULL);

	if (table && !reverse)
		BIO_printf(out, "%s\t%s\n", passwd, hash);
	else if (table && reverse)
		BIO_printf(out, "%s\t%s\n", hash, passwd);
	else
		BIO_printf(out, "%s\n", hash);
	return 1;
	
err:
	return 0;
	}
#else

int MAIN(int argc, char **argv)
	{
	fputs("Program not available.\n", stderr)
	EXIT(1);
	}
#endif