Return to passwd.c CVS log

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Rename struct ${app}_config to plain cfg

All the structs are static and we need to reach into them many times.
Having a shorter name is more concise and results in less visual clutter.
It also avoids many overlong lines and we will be able to get rid of some
unfortunate line wrapping down the road.

Discussed with jsing

/* $OpenBSD: passwd.c,v 1.14 2023/03/06 14:32:06 tb Exp $ */

#if defined OPENSSL_NO_MD5
#define NO_MD5CRYPT_1
#endif

#if !defined(OPENSSL_NO_DES) || !defined(NO_MD5CRYPT_1)

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

#include "apps.h"

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

#ifndef OPENSSL_NO_DES
#include <openssl/des.h>
#endif

#ifndef NO_MD5CRYPT_1
#include <openssl/md5.h>
#endif

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 use1, int useapr1);

static struct {
	char *infile;
	int in_stdin;
	int noverify;
	int quiet;
	int reverse;
	char *salt;
	int table;
	int use1;
	int useapr1;
	int usecrypt;
} cfg;

static const struct option passwd_options[] = {
#ifndef NO_MD5CRYPT_1
	{
		.name = "1",
		.desc = "Use MD5 based BSD password algorithm 1",
		.type = OPTION_FLAG,
		.opt.flag = &cfg.use1,
	},
	{
		.name = "apr1",
		.desc = "Use apr1 algorithm (Apache variant of BSD algorithm)",
		.type = OPTION_FLAG,
		.opt.flag = &cfg.useapr1,
	},
#endif
#ifndef OPENSSL_NO_DES
	{
		.name = "crypt",
		.desc = "Use crypt algorithm (default)",
		.type = OPTION_FLAG,
		.opt.flag = &cfg.usecrypt,
	},
#endif
	{
		.name = "in",
		.argname = "file",
		.desc = "Read passwords from specified file",
		.type = OPTION_ARG,
		.opt.arg = &cfg.infile,
	},
	{
		.name = "noverify",
		.desc = "Do not verify password",
		.type = OPTION_FLAG,
		.opt.flag = &cfg.noverify,
	},
	{
		.name = "quiet",
		.desc = "Do not output warnings",
		.type = OPTION_FLAG,
		.opt.flag = &cfg.quiet,
	},
	{
		.name = "reverse",
		.desc = "Reverse table columns (requires -table)",
		.type = OPTION_FLAG,
		.opt.flag = &cfg.reverse,
	},
	{
		.name = "salt",
		.argname = "string",
		.desc = "Use specified salt",
		.type = OPTION_ARG,
		.opt.arg = &cfg.salt,
	},
	{
		.name = "stdin",
		.desc = "Read passwords from stdin",
		.type = OPTION_FLAG,
		.opt.flag = &cfg.in_stdin,
	},
	{
		.name = "table",
		.desc = "Output cleartext and hashed passwords (tab separated)",
		.type = OPTION_FLAG,
		.opt.flag = &cfg.table,
	},
	{ NULL },
};

static void
passwd_usage(void)
{
        fprintf(stderr, "usage: passwd [-1 | -apr1 | -crypt] [-in file] "
	    "[-noverify] [-quiet]\n"
	    "    [-reverse] [-salt string] [-stdin] [-table] [password]\n\n");
        options_usage(passwd_options);
}

int
passwd_main(int argc, char **argv)
{
	char *passwd = NULL, **passwds = NULL;
	char *salt_malloc = NULL, *passwd_malloc = NULL;
	size_t passwd_malloc_size = 0;
	BIO *in = NULL, *out = NULL;
	int badopt = 0;
	int passed_salt = 0;
	size_t pw_maxlen = 0;
	int argsused;
	int ret = 1;

	if (pledge("stdio cpath wpath rpath tty", NULL) == -1) {
		perror("pledge");
		exit(1);
	}

	memset(&cfg, 0, sizeof(cfg));

	if (options_parse(argc, argv, passwd_options, NULL, &argsused) != 0) {
		passwd_usage();
		goto err;
	}

	if (argsused < argc)
		passwds = &argv[argsused];
	if (cfg.salt != NULL)
		passed_salt = 1;

	if (!cfg.usecrypt && !cfg.use1 &&
	    !cfg.useapr1)
		cfg.usecrypt = 1;	/* use default */
	if (cfg.usecrypt + cfg.use1 +
	    cfg.useapr1 > 1)
		badopt = 1;	/* conflicting options */

	/* Reject unsupported algorithms */
#ifdef OPENSSL_NO_DES
	if (cfg.usecrypt)
		badopt = 1;
#endif
#ifdef NO_MD5CRYPT_1
	if (cfg.use1 || cfg.useapr1)
		badopt = 1;
#endif

	if (badopt) {
		passwd_usage();
		goto err;
	}

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

	if (cfg.infile != NULL || cfg.in_stdin) {
		if ((in = BIO_new(BIO_s_file())) == NULL)
			goto err;
		if (cfg.infile != NULL) {
			assert(cfg.in_stdin == 0);
			if (BIO_read_filename(in, cfg.infile) <= 0)
				goto err;
		} else {
			assert(cfg.in_stdin);
			BIO_set_fp(in, stdin, BIO_NOCLOSE);
		}
	}
	if (cfg.usecrypt)
		pw_maxlen = 8;
	else if (cfg.use1 || cfg.useapr1)
		pw_maxlen = 256;/* arbitrary limit, should be enough for most
				 * passwords */

	if (passwds == NULL) {
		/* no passwords on the command line */

		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: ",
			    !(passed_salt || cfg.noverify)) != 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, &cfg.salt,
			    &salt_malloc, passwd, out, cfg.quiet,
			    cfg.table, cfg.reverse,
			    pw_maxlen, cfg.usecrypt,
			    cfg.use1, cfg.useapr1))
				goto err;
		} while (*passwds != NULL);
	} else {
		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, &cfg.salt,
				    &salt_malloc, passwd, out,
				    cfg.quiet, cfg.table,
				    cfg.reverse, pw_maxlen,
				    cfg.usecrypt, cfg.use1,
				    cfg.useapr1))
					goto err;
			}
			done = (r <= 0);
		} while (!done);
	}
	ret = 0;

 err:
	ERR_print_errors(bio_err);

	free(salt_malloc);
	free(passwd_malloc);

	BIO_free(in);
	BIO_free_all(out);

	return (ret);
}


#ifndef NO_MD5CRYPT_1
/* MD5-based password algorithm (should probably be available as a library
 * function; then the static buffer would not be acceptable).
 * For magic string "1", this should be compatible to the MD5-based BSD
 * password algorithm.
 * For 'magic' string "apr1", this is compatible to the MD5-based Apache
 * password algorithm.
 * (Apparently, the Apache password algorithm is identical except that the
 * 'magic' string was changed -- the laziest application of the NIH principle
 * I've ever encountered.)
 */
static char *
md5crypt(const char *passwd, const char *magic, const char *salt)
{
	static char out_buf[6 + 9 + 24 + 2];	/* "$apr1$..salt..$.......md5h
						 * ash..........\0" */
	unsigned char buf[MD5_DIGEST_LENGTH];
	char *salt_out;
	int n;
	unsigned int i;
	EVP_MD_CTX *md = NULL, *md2 = NULL;
	size_t passwd_len, salt_len;

	passwd_len = strlen(passwd);
	out_buf[0] = '$';
	out_buf[1] = 0;
	assert(strlen(magic) <= 4);	/* "1" or "apr1" */
	strlcat(out_buf, magic, sizeof(out_buf));
	strlcat(out_buf, "$", sizeof(out_buf));
	strlcat(out_buf, salt, sizeof(out_buf));
	assert(strlen(out_buf) <= 6 + 8);	/* "$apr1$..salt.." */
	salt_out = out_buf + 2 + strlen(magic);
	salt_len = strlen(salt_out);
	assert(salt_len <= 8);

	if ((md = EVP_MD_CTX_new()) == NULL)
		goto err;
	if (!EVP_DigestInit_ex(md, EVP_md5(), NULL))
		goto err;
	if (!EVP_DigestUpdate(md, passwd, passwd_len))
		goto err;
	if (!EVP_DigestUpdate(md, "$", 1))
		goto err;
	if (!EVP_DigestUpdate(md, magic, strlen(magic)))
		goto err;
	if (!EVP_DigestUpdate(md, "$", 1))
		goto err;
	if (!EVP_DigestUpdate(md, salt_out, salt_len))
		goto err;

	if ((md2 = EVP_MD_CTX_new()) == NULL)
		goto err;
	if (!EVP_DigestInit_ex(md2, EVP_md5(), NULL))
		goto err;
	if (!EVP_DigestUpdate(md2, passwd, passwd_len))
		goto err;
	if (!EVP_DigestUpdate(md2, salt_out, salt_len))
		goto err;
	if (!EVP_DigestUpdate(md2, passwd, passwd_len))
		goto err;
	if (!EVP_DigestFinal_ex(md2, buf, NULL))
		goto err;

	for (i = passwd_len; i > sizeof buf; i -= sizeof buf) {
		if (!EVP_DigestUpdate(md, buf, sizeof buf))
			goto err;
	}
	if (!EVP_DigestUpdate(md, buf, i))
		goto err;

	n = passwd_len;
	while (n) {
		if (!EVP_DigestUpdate(md, (n & 1) ? "\0" : passwd, 1))
			goto err;
		n >>= 1;
	}
	if (!EVP_DigestFinal_ex(md, buf, NULL))
		goto err;

	for (i = 0; i < 1000; i++) {
		if (!EVP_DigestInit_ex(md2, EVP_md5(), NULL))
			goto err;
		if (!EVP_DigestUpdate(md2,
		    (i & 1) ? (unsigned const char *) passwd : buf,
		    (i & 1) ? passwd_len : sizeof buf))
			goto err;
		if (i % 3) {
			if (!EVP_DigestUpdate(md2, salt_out, salt_len))
				goto err;
		}
		if (i % 7) {
			if (!EVP_DigestUpdate(md2, passwd, passwd_len))
				goto err;
		}
		if (!EVP_DigestUpdate(md2,
		    (i & 1) ? buf : (unsigned const char *) passwd,
		    (i & 1) ? sizeof buf : passwd_len))
			goto err;
		if (!EVP_DigestFinal_ex(md2, buf, NULL))
			goto err;
	}
	EVP_MD_CTX_free(md2);
	md2 = NULL;

	{
		/* 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];
		assert(16 == sizeof buf_perm);

		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));
	}
	EVP_MD_CTX_free(md);

	return out_buf;
 err:
	EVP_MD_CTX_free(md);
	EVP_MD_CTX_free(md2);

	return NULL;
}
#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 use1, 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 OPENSSL_NO_DES
		if (usecrypt) {
			if (*salt_malloc_p == NULL) {
				*salt_p = *salt_malloc_p = malloc(3);
				if (*salt_malloc_p == NULL)
					goto err;
			}
			arc4random_buf(*salt_p, 2);
			(*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;
		}
#endif				/* !OPENSSL_NO_DES */

#ifndef NO_MD5CRYPT_1
		if (use1 || useapr1) {
			int i;

			if (*salt_malloc_p == NULL) {
				*salt_p = *salt_malloc_p = malloc(9);
				if (*salt_malloc_p == NULL)
					goto err;
			}
			arc4random_buf(*salt_p, 8);

			for (i = 0; i < 8; i++)
				(*salt_p)[i] = cov_2char[(*salt_p)[i] & 0x3f];	/* 6 bits */
			(*salt_p)[8] = 0;
		}
#endif				/* !NO_MD5CRYPT_1 */
	}
	assert(*salt_p != NULL);

	/* truncate password if necessary */
	if ((strlen(passwd) > pw_maxlen)) {
		if (!quiet)
			BIO_printf(bio_err,
			    "Warning: truncating password to %zu characters\n",
			    pw_maxlen);
		passwd[pw_maxlen] = 0;
	}
	assert(strlen(passwd) <= pw_maxlen);

	/* now compute password hash */
#ifndef OPENSSL_NO_DES
	if (usecrypt)
		hash = DES_crypt(passwd, *salt_p);
#endif
#ifndef NO_MD5CRYPT_1
	if (use1 || useapr1)
		if ((hash = md5crypt(passwd, (use1 ? "1" : "apr1"), *salt_p)) == NULL)
			goto err;
#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:
	free(*salt_malloc_p);
	*salt_malloc_p = NULL;
	return 0;
}
#else

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