port/gen/crypt.c

/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License (the "License").
 * You may not use this file except in compliance with the License.
 *
 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
 * or http://www.opensolaris.org/os/licensing.
 * See the License for the specific language governing permissions
 * and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL HEADER in each
 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
 * If applicable, add the following below this CDDL HEADER, with the
 * fields enclosed by brackets "[]" replaced with your own identifying
 * information: Portions Copyright [yyyy] [name of copyright owner]
 *
 * CDDL HEADER END
 */

/*
 * Copyright 2009 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */

#pragma weak _crypt = crypt
#pragma weak _encrypt = encrypt
#pragma weak _setkey = setkey

#include "lint.h"
#include "mtlib.h"
#include <synch.h>
#include <thread.h>
#include <ctype.h>
#include <dlfcn.h>
#include <errno.h>
#include <stdio.h>
#include <strings.h>
#include <stdlib.h>
#include <sys/time.h>
#include <limits.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <syslog.h>
#include <unistd.h>
#include <atomic.h>

#include <crypt.h>
#include <libc.h>
#include "tsd.h"

#define CRYPT_ALGORITHMS_ALLOW      "CRYPT_ALGORITHMS_ALLOW"
#define CRYPT_ALGORITHMS_DEPRECATE  "CRYPT_ALGORITHMS_DEPRECATE"
#define CRYPT_DEFAULT           "CRYPT_DEFAULT"
#define CRYPT_UNIX          "__unix__"

#define CRYPT_CONFFILE      "/etc/security/crypt.conf"
#define POLICY_CONF_FILE    "/etc/security/policy.conf"

#define CRYPT_CONFLINELENGTH    1024

#define CRYPT_MODULE_ISA    "/$ISA/"
#ifdef  _LP64
#define CRYPT_MODULE_DIR    "/usr/lib/security/64/"
#define CRYPT_ISA_DIR       "/64/"
#else   /* !_LP64 */
#define CRYPT_MODULE_DIR    "/usr/lib/security/"
#define CRYPT_ISA_DIR       "/"
#endif  /* _LP64 */

/*
 * MAX_ALGNAME_LEN:
 *
 * In practical terms this is probably never any bigger than about 10, but...
 *
 * It has to fix the encrypted password filed of struct spwd it is
 * theoretically the maximum length of the cipher minus the magic $ sign.
 * Though that would be unexpected.
 * Since it also has to fit in crypt.conf it is CRYPT_CONFLINELENGTH
 * minus the path to the module and the minimum white space.
 *
 * CRYPT_MAXCIPHERTEXTLEN is defined in crypt.h and is smaller than
 * CRYPT_CONFLINELENGTH, and probably always will be.
 */
#define MAX_ALGNAME_LEN (CRYPT_MAXCIPHERTEXTLEN - 1)

struct crypt_alg_s {
    void    *a_libhandle;
    char    *(*a_genhash)(char *, const size_t, const char *,
            const char *, const char **);
    char    *(*a_gensalt)(char *, const size_t,
            const char *, const struct passwd *, const char **);
    char    **a_params;
    int a_nparams;
};

struct crypt_policy_s {
    char    *cp_default;
    char    *cp_allow;
    char    *cp_deny;
};

enum crypt_policy_error_e {
    CPE_BOTH = 1,
    CPE_MULTI
};

static struct crypt_policy_s *getcryptpolicy(void);
static void free_crypt_policy(struct crypt_policy_s *policy);
static struct crypt_alg_s  *getalgbyname(const char *algname, boolean_t *found);
static void free_crypt_alg(struct crypt_alg_s *alg);
static char *getalgfromsalt(const char *salt);
static boolean_t alg_valid(const char *algname,
    const struct crypt_policy_s *policy);
static char *isa_path(const char *path);

static char *_unix_crypt(const char *pw, const char *salt, char *iobuf);
static char *_unix_crypt_gensalt(char *gsbuffer, size_t gsbufflen,
        const char *oldpuresalt, const struct passwd *userinfo,
        const char *params[]);


/*
 * crypt - string encoding function
 *
 * This function encodes strings in a suitable for for secure storage
 * as passwords.  It generates the password hash given the plaintext and salt.
 *
 * If the first character of salt is "$" then we use crypt.conf(4) to
 * determine which plugin to use and run the crypt_genhash_impl(3c) function
 * from it.
 * Otherwise we use the old unix algorithm.
 *
 * RETURN VALUES
 *  On Success we return a pointer to the encoded string.  The
 *  return value points to thread specific static data and should NOT
 *  be passed free(3c).
 *  On failure we return NULL and set errno to one of:
 *      EINVAL, ELIBACC, ENOMEM, ENOSYS.
 */
char *
crypt(const char *plaintext, const char *salt)
{
    struct crypt_alg_s *alg;
    char *ctbuffer;
    char *ciphertext;
    char *algname;
    boolean_t found;

    ctbuffer = tsdalloc(_T_CRYPT, CRYPT_MAXCIPHERTEXTLEN, NULL);
    if (ctbuffer == NULL)
        return (NULL);
    bzero(ctbuffer, CRYPT_MAXCIPHERTEXTLEN);

    /*
     * '$' is never a possible salt char with the traditional unix
     * algorithm.  If the salt passed in is NULL or the first char
     * of the salt isn't a $ then do the traditional thing.
     * We also do the traditional thing if the salt is only 1 char.
     */
    if (salt == NULL || salt[0] != '$' || strlen(salt) == 1) {
        return (_unix_crypt(plaintext, salt, ctbuffer));
    }

    /*
     * Find the algorithm name from the salt and look it up in
     * crypt.conf(4) to find out what shared object to use.
     * If we can't find it in crypt.conf then getalgbyname would
     * have returned with found = B_FALSE so we use the unix algorithm.
     * If alg is NULL but found = B_TRUE then there is a problem with
     * the plugin so we fail leaving errno set to what getalgbyname()
     * set it to or EINVAL it if wasn't set.
     */
    if ((algname = getalgfromsalt(salt)) == NULL) {
        return (NULL);
    }

    errno = 0;
    alg = getalgbyname(algname, &found);
    if ((alg == NULL) || !found) {
        if (errno == 0)
            errno = EINVAL;
        ciphertext = NULL;
        goto cleanup;
    } else if (!found) {
        ciphertext = _unix_crypt(plaintext, salt, ctbuffer);
    } else {
        ciphertext = alg->a_genhash(ctbuffer, CRYPT_MAXCIPHERTEXTLEN,
            plaintext, salt, (const char **)alg->a_params);
    }

cleanup:
    free_crypt_alg(alg);
    if (algname != NULL)
        free(algname);

    return (ciphertext);
}

/*
 * crypt_gensalt - generate salt string for string encoding
 *
 * This function generates the salt string pased to crypt(3c).
 * If oldsalt is NULL, the use the default algorithm.
 * Other wise check the policy in policy.conf to ensure that it is
 * either still allowed or not deprecated.
 *
 * RETURN VALUES
 *  Return a pointer to the new salt, the caller is responsible
 *  for using free(3c) on the return value.
 *  Returns NULL on error and sets errno to one of:
 *      EINVAL, ELIBACC, ENOMEM
 */
char *
crypt_gensalt(const char *oldsalt, const struct passwd *userinfo)
{
    struct crypt_alg_s *alg = NULL;
    struct crypt_policy_s *policy = NULL;
    char *newsalt = NULL;
    char *gsbuffer;
    char *algname = NULL;
    boolean_t found;

    gsbuffer = calloc(CRYPT_MAXCIPHERTEXTLEN, sizeof (char *));
    if (gsbuffer == NULL) {
        errno = ENOMEM;
        goto cleanup;
    }

    policy = getcryptpolicy();
    if (policy == NULL) {
        errno = EINVAL;
        goto cleanup;
    }

    algname = getalgfromsalt(oldsalt);
    if (!alg_valid(algname, policy)) {
        free(algname);
        algname = strdup(policy->cp_default);
    }

    if (strcmp(algname, CRYPT_UNIX) == 0) {
        newsalt = _unix_crypt_gensalt(gsbuffer, CRYPT_MAXCIPHERTEXTLEN,
            oldsalt, userinfo, NULL);
    } else {
        errno = 0;
        alg = getalgbyname(algname, &found);
        if (alg == NULL || !found) {
            if (errno == 0)
                errno = EINVAL;
            goto cleanup;
        }
        newsalt = alg->a_gensalt(gsbuffer, CRYPT_MAXCIPHERTEXTLEN,
            oldsalt, userinfo, (const char **)alg->a_params);
    }

cleanup:
    free_crypt_policy(policy);
    free_crypt_alg(alg);
    if (newsalt == NULL && gsbuffer != NULL)
        free(gsbuffer);
    if (algname != NULL)
        free(algname);

    return (newsalt);
}

/*
 * ===========================================================================
 * The remainder of this file contains internal interfaces for
 * the implementation of crypt(3c) and crypt_gensalt(3c)
 * ===========================================================================
 */


/*
 * getalgfromsalt - extract the algorithm name from the salt string
 */
static char *
getalgfromsalt(const char *salt)
{
    char algname[CRYPT_MAXCIPHERTEXTLEN];
    int i;
    int j;

    if (salt == NULL || strlen(salt) > CRYPT_MAXCIPHERTEXTLEN)
        return (NULL);
    /*
     * Salts are in this format:
     * $<algname>[,var=val,[var=val ...][$puresalt]$<ciphertext>
     *
     * The only bit we need to worry about here is extracting the
     * name which is the string between the first "$" and the first
     * of "," or second "$".
     */
    if (salt[0] != '$') {
        return (strdup(CRYPT_UNIX));
    }

    i = 1;
    j = 0;
    while (salt[i] != '\0' && salt[i] != '$' && salt[i] != ',') {
        algname[j] = salt[i];
        i++;
        j++;
    }
    if (j == 0)
        return (NULL);

    algname[j] = '\0';

    return (strdup(algname));
}


/*
 * log_invalid_policy - syslog helper
 */
static void
log_invalid_policy(enum crypt_policy_error_e error, char *value)
{
    switch (error) {
    case CPE_BOTH:
        syslog(LOG_AUTH | LOG_ERR,
            "crypt(3c): %s contains both %s and %s; only one may be "
            "specified, using first entry in file.", POLICY_CONF_FILE,
            CRYPT_ALGORITHMS_ALLOW, CRYPT_ALGORITHMS_DEPRECATE);
        break;
    case CPE_MULTI:
        syslog(LOG_AUTH | LOG_ERR,
            "crypt(3c): %s contains multiple %s entries;"
            "using first entry file.", POLICY_CONF_FILE, value);
        break;
    }
}

static char *
getval(const char *ival)
{
    char *tmp;
    char *oval;
    int off;

    if (ival == NULL)
        return (NULL);

    if ((tmp = strchr(ival, '=')) == NULL)
        return (NULL);

    oval = strdup(tmp + 1); /* everything after the "=" */
    if (oval == NULL)
        return (NULL);
    off = strlen(oval) - 1;
    if (off < 0) {
        free(oval);
        return (NULL);
    }
    if (oval[off] == '\n')
        oval[off] = '\0';

    return (oval);
}

/*
 * getcryptpolicy - read /etc/security/policy.conf into a crypt_policy_s
 */
static struct crypt_policy_s *
getcryptpolicy(void)
{
    FILE    *pconf;
    char    line[BUFSIZ];
    struct crypt_policy_s *policy;

    if ((pconf = fopen(POLICY_CONF_FILE, "rF")) == NULL) {
        return (NULL);
    }

    policy = malloc(sizeof (struct crypt_policy_s));
    if (policy == NULL) {
        return (NULL);
    }
    policy->cp_default = NULL;
    policy->cp_allow = NULL;
    policy->cp_deny = NULL;

    while (!feof(pconf) &&
        (fgets(line, sizeof (line), pconf) != NULL)) {
        if (strncasecmp(CRYPT_DEFAULT, line,
            strlen(CRYPT_DEFAULT)) == 0) {
            if (policy->cp_default != NULL) {
                log_invalid_policy(CPE_MULTI, CRYPT_DEFAULT);
            } else {
                policy->cp_default = getval(line);
            }
        }
        if (strncasecmp(CRYPT_ALGORITHMS_ALLOW, line,
            strlen(CRYPT_ALGORITHMS_ALLOW)) == 0) {
            if (policy->cp_deny != NULL) {
                log_invalid_policy(CPE_BOTH, NULL);
            } else if (policy->cp_allow != NULL) {
                log_invalid_policy(CPE_MULTI,
                    CRYPT_ALGORITHMS_ALLOW);
            } else {
                policy->cp_allow = getval(line);
            }
        }
        if (strncasecmp(CRYPT_ALGORITHMS_DEPRECATE, line,
            strlen(CRYPT_ALGORITHMS_DEPRECATE)) == 0) {
            if (policy->cp_allow != NULL) {
                log_invalid_policy(CPE_BOTH, NULL);
            } else if (policy->cp_deny != NULL) {
                log_invalid_policy(CPE_MULTI,
                    CRYPT_ALGORITHMS_DEPRECATE);
            } else {
                policy->cp_deny = getval(line);
            }
        }
    }
    (void) fclose(pconf);

    if (policy->cp_default == NULL) {
        policy->cp_default = strdup(CRYPT_UNIX);
        if (policy->cp_default == NULL)
            free_crypt_policy(policy);
    }

    return (policy);
}


/*
 * alg_valid - is this algorithm valid given the policy ?
 */
static boolean_t
alg_valid(const char *algname, const struct crypt_policy_s *policy)
{
    char *lasts;
    char *list;
    char *entry;
    boolean_t allowed = B_FALSE;

    if ((algname == NULL) || (policy == NULL)) {
        return (B_FALSE);
    }

    if (strcmp(algname, policy->cp_default) == 0) {
        return (B_TRUE);
    }

    if (policy->cp_deny != NULL) {
        list = policy->cp_deny;
        allowed = B_FALSE;
    } else if (policy->cp_allow != NULL) {
        list = policy->cp_allow;
        allowed = B_TRUE;
    } else {
        /*
         * Neither of allow or deny policies are set so anything goes.
         */
        return (B_TRUE);
    }
    lasts = list;
    while ((entry = strtok_r(NULL, ",", &lasts)) != NULL) {
        if (strcmp(entry, algname) == 0) {
            return (allowed);
        }
    }

    return (!allowed);
}

/*
 * getalgbyname - read crypt.conf(4) looking for algname
 *
 * RETURN VALUES
 *  On error NULL and errno is set
 *  On success the alg details including an open handle to the lib
 *  If crypt.conf(4) is okay but algname doesn't exist in it then
 *  return NULL the caller should then use the default algorithm
 *  as per the policy.
 */
static struct crypt_alg_s *
getalgbyname(const char *algname, boolean_t *found)
{
    struct stat stb;
    int     configfd;
    FILE        *fconf = NULL;
    struct crypt_alg_s *alg = NULL;
    char        line[CRYPT_CONFLINELENGTH];
    int     linelen = 0;
    int     lineno = 0;
    char        *pathname = NULL;
    char        *lasts = NULL;
    char        *token = NULL;

    *found = B_FALSE;
    if ((algname == NULL) || (strcmp(algname, CRYPT_UNIX) == 0)) {
        return (NULL);
    }

    if ((configfd = open(CRYPT_CONFFILE, O_RDONLY)) == -1) {
        syslog(LOG_ALERT, "crypt: open(%s) failed: %s",
            CRYPT_CONFFILE, strerror(errno));
        return (NULL);
    }

    /*
     * Stat the file so we can check modes and ownerships
     */
    if (fstat(configfd, &stb) < 0) {
        syslog(LOG_ALERT, "crypt: stat(%s) failed: %s",
            CRYPT_CONFFILE, strerror(errno));
        goto cleanup;
    }

    /*
     * Check the ownership of the file
     */
    if (stb.st_uid != (uid_t)0) {
        syslog(LOG_ALERT,
            "crypt: Owner of %s is not root", CRYPT_CONFFILE);
        goto cleanup;
    }

    /*
     * Check the modes on the file
     */
    if (stb.st_mode & S_IWGRP) {
        syslog(LOG_ALERT,
            "crypt: %s writable by group", CRYPT_CONFFILE);
        goto cleanup;
    }
    if (stb.st_mode & S_IWOTH) {
        syslog(LOG_ALERT,
            "crypt: %s writable by world", CRYPT_CONFFILE);
        goto cleanup;
    }

    if ((fconf = fdopen(configfd, "rF")) == NULL) {
        syslog(LOG_ALERT, "crypt: fdopen(%d) failed: %s",
            configfd, strerror(errno));
        goto cleanup;
    }

    /*
     * /etc/security/crypt.conf has 3 fields:
     * <algname>    <pathname>  [<name[=val]>[<name[=val]>]]
     */
    errno = 0;
    while (!(*found) &&
        ((fgets(line, sizeof (line), fconf) != NULL) && !feof(fconf))) {
        lineno++;
        /*
         * Skip over comments
         */
        if ((line[0] == '#') || (line[0] == '\n')) {
            continue;
        }

        linelen = strlen(line);
        line[--linelen] = '\0'; /* chop the trailing \n */

        token = strtok_r(line, " \t", &lasts);
        if (token == NULL) {
            continue;
        }
        if (strcmp(token, algname) == 0) {
            *found = B_TRUE;
        }
    }
    if (!found) {
        errno = EINVAL;
        goto cleanup;
    }

    token = strtok_r(NULL, " \t", &lasts);
    if (token == NULL) {
        /*
         * Broken config file
         */
        syslog(LOG_ALERT, "crypt(3c): %s may be corrupt at line %d",
            CRYPT_CONFFILE, lineno);
        *found = B_FALSE;
        errno = EINVAL;
        goto cleanup;
    }

    if ((pathname = isa_path(token)) == NULL) {
        if (errno != ENOMEM)
            errno = EINVAL;
        *found = B_FALSE;
        goto cleanup;
    }

    if ((alg = malloc(sizeof (struct crypt_alg_s))) == NULL) {
        *found = B_FALSE;
        goto cleanup;
    }
    alg->a_libhandle = NULL;
    alg->a_genhash = NULL;
    alg->a_gensalt = NULL;
    alg->a_params = NULL;
    alg->a_nparams = 0;

    /*
     * The rest of the line is module specific params, space
     * seprated. We wait until after we have checked the module is
     * valid before parsing them into a_params, this saves us
     * having to free them later if there is a problem.
     */
    if ((alg->a_libhandle = dlopen(pathname, RTLD_NOW)) == NULL) {
        syslog(LOG_ERR, "crypt(3c) unable to dlopen %s: %s",
            pathname, dlerror());
        errno = ELIBACC;
        *found = B_FALSE;
        goto cleanup;
    }

    alg->a_genhash =
        (char *(*)())dlsym(alg->a_libhandle, "crypt_genhash_impl");
    if (alg->a_genhash == NULL) {
        syslog(LOG_ERR, "crypt(3c) unable to find cryp_genhash_impl"
            "symbol in %s: %s", pathname, dlerror());
        errno = ELIBACC;
        *found = B_FALSE;
        goto cleanup;
    }
    alg->a_gensalt =
        (char *(*)())dlsym(alg->a_libhandle, "crypt_gensalt_impl");
    if (alg->a_gensalt == NULL) {
        syslog(LOG_ERR, "crypt(3c) unable to find crypt_gensalt_impl"
            "symbol in %s: %s", pathname, dlerror());
        errno = ELIBACC;
        *found = B_FALSE;
        goto cleanup;
    }

    /*
     * We have a good module so build the a_params if we have any.
     * Count how much space we need first and then allocate an array
     * to hold that many module params.
     */
    if (lasts != NULL) {
        int nparams = 0;
        char *tparams;
        char *tplasts;

        if ((tparams = strdup(lasts)) == NULL) {
            *found = B_FALSE;
            goto cleanup;
        }

        (void) strtok_r(tparams, " \t", &tplasts);
        do {
            nparams++;
        } while (strtok_r(NULL, " \t", &tplasts) != NULL);
        free(tparams);

        alg->a_params = calloc(nparams + 1, sizeof (char *));
        if (alg->a_params == NULL) {
            *found = B_FALSE;
            goto cleanup;
        }

        while ((token = strtok_r(NULL, " \t", &lasts)) != NULL) {
            alg->a_params[alg->a_nparams++] = token;
        }
    }

cleanup:
    if (*found == B_FALSE) {
        free_crypt_alg(alg);
        alg = NULL;
    }

    if (pathname != NULL) {
        free(pathname);
    }

    if (fconf != NULL) {
        (void) fclose(fconf);
    } else {
        (void) close(configfd);
    }

    return (alg);
}

static void
free_crypt_alg(struct crypt_alg_s *alg)
{
    if (alg == NULL)
        return;

    if (alg->a_libhandle != NULL) {
        (void) dlclose(alg->a_libhandle);
    }
    if (alg->a_nparams != NULL) {
        free(alg->a_params);
    }
    free(alg);
}

static void
free_crypt_policy(struct crypt_policy_s *policy)
{
    if (policy == NULL)
        return;

    if (policy->cp_default != NULL) {
        bzero(policy->cp_default, strlen(policy->cp_default));
        free(policy->cp_default);
        policy->cp_default = NULL;
    }

    if (policy->cp_allow != NULL) {
        bzero(policy->cp_allow, strlen(policy->cp_allow));
        free(policy->cp_allow);
        policy->cp_allow = NULL;
    }

    if (policy->cp_deny != NULL) {
        bzero(policy->cp_deny, strlen(policy->cp_deny));
        free(policy->cp_deny);
        policy->cp_deny = NULL;
    }

    free(policy);
}


/*
 * isa_path - prepend the default dir or patch up the $ISA in path
 *  Caller is responsible for calling free(3c) on the result.
 */
static char *
isa_path(const char *path)
{
    char *ret = NULL;

    if ((path == NULL) || (strlen(path) > PATH_MAX)) {
        return (NULL);
    }

    ret = calloc(PATH_MAX, sizeof (char));

    /*
     * Module path doesn't start with "/" then prepend
     * the default search path CRYPT_MODULE_DIR (/usr/lib/security/$ISA)
     */
    if (path[0] != '/') {
        if (snprintf(ret, PATH_MAX, "%s%s", CRYPT_MODULE_DIR,
            path) > PATH_MAX) {
            free(ret);
            return (NULL);
        }
    } else { /* patch up $ISA */
        char *isa;

        if ((isa = strstr(path, CRYPT_MODULE_ISA)) != NULL) {
            *isa = '\0';
            isa += strlen(CRYPT_MODULE_ISA);
            if (snprintf(ret, PATH_MAX, "%s%s%s", path,
                CRYPT_ISA_DIR, isa) > PATH_MAX) {
                free(ret);
                return (NULL);
            }
        } else {
            free(ret);
            ret = strdup(path);
        }
    }

    return (ret);
}


/*ARGSUSED*/
static char *
_unix_crypt_gensalt(char *gsbuffer,
        size_t gsbufflen,
        const char *oldpuresalt,
        const struct passwd *userinfo,
        const char *argv[])
{
    static const char saltchars[] =
        "./0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz";
    struct timeval tv;

    (void) gettimeofday(&tv, (void *) 0);
    srand48(tv.tv_sec ^ tv.tv_usec);
    gsbuffer[0] = saltchars[lrand48() % 64]; /* lrand48() is MT-SAFE */
    gsbuffer[1] = saltchars[lrand48() % 64]; /* lrand48() is MT-SAFE */
    gsbuffer[2] = '\0';

    return (gsbuffer);
}

/*
 * The rest of the code below comes from the old crypt.c and is the
 * implementation of the hardwired/fallback traditional algorithm
 * It has been otimized to take better advantage of MT features.
 *
 * It is included here to reduce the overhead of dlopen()
 * for the common case.
 */


/*  Copyright (c) 1988 AT&T */
/*    All Rights Reserved   */


/*
 * This program implements a data encryption algorithm to encrypt passwords.
 */

static mutex_t crypt_lock = DEFAULTMUTEX;
#define TSDBUFSZ    (66 + 16)

static const char IP[] = {
    58, 50, 42, 34, 26, 18, 10, 2,
    60, 52, 44, 36, 28, 20, 12, 4,
    62, 54, 46, 38, 30, 22, 14, 6,
    64, 56, 48, 40, 32, 24, 16, 8,
    57, 49, 41, 33, 25, 17, 9, 1,
    59, 51, 43, 35, 27, 19, 11, 3,
    61, 53, 45, 37, 29, 21, 13, 5,
    63, 55, 47, 39, 31, 23, 15, 7,
};

static const char FP[] = {
    40, 8, 48, 16, 56, 24, 64, 32,
    39, 7, 47, 15,  55, 23, 63, 31,
    38, 6, 46, 14, 54, 22, 62, 30,
    37, 5, 45, 13, 53, 21, 61, 29,
    36, 4, 44, 12, 52, 20, 60, 28,
    35, 3, 43, 11, 51, 19, 59, 27,
    34, 2, 42, 10, 50, 18, 58, 26,
    33, 1, 41, 9, 49, 17, 57, 25,
};

static const char PC1_C[] = {
    57, 49, 41, 33, 25, 17, 9,
    1, 58, 50, 42, 34, 26, 18,
    10, 2, 59, 51, 43, 35, 27,
    19, 11, 3, 60, 52, 44, 36,
};

static const char PC1_D[] = {
    63, 55, 47, 39, 31, 23, 15,
    7, 62, 54, 46, 38, 30, 22,
    14, 6, 61, 53, 45, 37, 29,
    21, 13, 5, 28, 20, 12, 4,
};

static const char shifts[] = {
    1, 1, 2, 2, 2, 2, 2, 2, 1, 2, 2, 2, 2, 2, 2, 1,
};

static const char PC2_C[] = {
    14, 17, 11, 24, 1, 5,
    3, 28, 15, 6, 21, 10,
    23, 19, 12, 4, 26, 8,
    16, 7, 27, 20, 13, 2,
};

static const char PC2_D[] = {
    41, 52, 31, 37, 47, 55,
    30, 40, 51, 45, 33, 48,
    44, 49, 39, 56, 34, 53,
    46, 42, 50, 36, 29, 32,
};

static char C[28];
static char D[28];
static char *KS;

static char E[48];
static const char e2[] = {
    32, 1, 2, 3, 4, 5,
    4, 5, 6, 7, 8, 9,
    8, 9, 10, 11, 12, 13,
    12, 13, 14, 15, 16, 17,
    16, 17, 18, 19, 20, 21,
    20, 21, 22, 23, 24, 25,
    24, 25, 26, 27, 28, 29,
    28, 29, 30, 31, 32, 1,
};

/*
 * The KS array (768 bytes) is allocated once, and only if
 * one of _unix_crypt(), encrypt() or setkey() is called.
 * The complexity below is due to the fact that calloc()
 * must not be called while holding any locks.
 */
static int
allocate_KS(void)
{
    char *ks;
    int failed;
    int assigned;

    if (KS != NULL) {       /* already allocated */
        membar_consumer();
        return (0);
    }

    ks = calloc(16, 48 * sizeof (char));
    failed = 0;
    lmutex_lock(&crypt_lock);
    if (KS != NULL) {   /* someone else got here first */
        assigned = 0;
    } else {
        assigned = 1;
        membar_producer();
        if ((KS = ks) == NULL)  /* calloc() failed */
            failed = 1;
    }
    lmutex_unlock(&crypt_lock);
    if (!assigned)
        free(ks);
    return (failed);
}

static void
unlocked_setkey(const char *key)
{
    int i, j, k;
    char t;

    for (i = 0; i < 28; i++) {
        C[i] = key[PC1_C[i]-1];
        D[i] = key[PC1_D[i]-1];
    }
    for (i = 0; i < 16; i++) {
        for (k = 0; k < shifts[i]; k++) {
            t = C[0];
            for (j = 0; j < 28-1; j++)
                C[j] = C[j+1];
            C[27] = t;
            t = D[0];
            for (j = 0; j < 28-1; j++)
                D[j] = D[j+1];
            D[27] = t;
        }
        for (j = 0; j < 24; j++) {
            int index = i * 48;

            *(KS+index+j) = C[PC2_C[j]-1];
            *(KS+index+j+24) = D[PC2_D[j]-28-1];
        }
    }
    for (i = 0; i < 48; i++)
        E[i] = e2[i];
}

static const char S[8][64] = {
    14, 4, 13, 1, 2, 15, 11, 8, 3, 10, 6, 12, 5, 9, 0, 7,
    0, 15, 7, 4, 14, 2, 13, 1, 10, 6, 12, 11, 9, 5, 3, 8,
    4, 1, 14, 8, 13, 6, 2, 11, 15, 12, 9, 7, 3, 10, 5, 0,
    15, 12, 8, 2, 4, 9, 1, 7, 5, 11, 3, 14, 10, 0, 6, 13,

    15, 1, 8, 14, 6, 11, 3, 4, 9, 7, 2, 13, 12, 0, 5, 10,
    3, 13, 4, 7, 15, 2, 8, 14, 12, 0, 1, 10, 6, 9, 11, 5,
    0, 14, 7, 11, 10, 4, 13, 1, 5, 8, 12, 6, 9, 3, 2, 15,
    13, 8, 10, 1, 3, 15, 4, 2, 11, 6, 7, 12, 0, 5, 14, 9,

    10, 0, 9, 14, 6, 3, 15, 5, 1, 13, 12, 7, 11, 4, 2, 8,
    13, 7, 0, 9, 3, 4, 6, 10, 2, 8, 5, 14, 12, 11, 15, 1,
    13, 6, 4, 9, 8, 15, 3, 0, 11, 1, 2, 12, 5, 10, 14, 7,
    1, 10, 13, 0, 6, 9, 8, 7, 4, 15, 14, 3, 11, 5, 2, 12,

    7, 13, 14, 3, 0, 6, 9, 10, 1, 2, 8, 5, 11, 12, 4, 15,
    13, 8, 11, 5, 6, 15, 0, 3, 4, 7, 2, 12, 1, 10, 14, 9,
    10, 6, 9, 0, 12, 11, 7, 13, 15, 1, 3, 14, 5, 2, 8, 4,
    3, 15, 0, 6, 10, 1, 13, 8, 9, 4, 5, 11, 12, 7, 2, 14,

    2, 12, 4, 1, 7, 10, 11, 6, 8, 5, 3, 15, 13, 0, 14, 9,
    14, 11, 2, 12, 4, 7, 13, 1, 5, 0, 15, 10, 3, 9, 8, 6,
    4, 2, 1, 11, 10, 13, 7, 8, 15, 9, 12, 5, 6, 3, 0, 14,
    11, 8, 12, 7, 1, 14, 2, 13, 6, 15, 0, 9, 10, 4, 5, 3,

    12, 1, 10, 15, 9, 2, 6, 8, 0, 13, 3, 4, 14, 7, 5, 11,
    10, 15, 4, 2, 7, 12, 9, 5, 6, 1, 13, 14, 0, 11, 3, 8,
    9, 14, 15, 5, 2, 8, 12, 3, 7, 0, 4, 10, 1, 13, 11, 6,
    4, 3, 2, 12, 9, 5, 15, 10, 11, 14, 1, 7, 6, 0, 8, 13,

    4, 11, 2, 14, 15, 0, 8, 13, 3, 12, 9, 7, 5, 10, 6, 1,
    13, 0, 11, 7, 4, 9, 1, 10, 14, 3, 5, 12, 2, 15, 8, 6,
    1, 4, 11, 13, 12, 3, 7, 14, 10, 15, 6, 8, 0, 5, 9, 2,
    6, 11, 13, 8, 1, 4, 10, 7, 9, 5, 0, 15, 14, 2, 3, 12,

    13, 2, 8, 4, 6, 15, 11, 1, 10, 9, 3, 14, 5, 0, 12, 7,
    1, 15, 13, 8, 10, 3, 7, 4, 12, 5, 6, 11, 0, 14, 9, 2,
    7, 11, 4, 1, 9, 12, 14, 2, 0, 6, 10, 13, 15, 3, 5, 8,
    2, 1, 14, 7, 4, 10, 8, 13, 15, 12, 9, 0, 3, 5, 6, 11,
};

static const char P[] = {
    16, 7, 20, 21,
    29, 12, 28, 17,
    1, 15, 23, 26,
    5, 18, 31, 10,
    2, 8, 24, 14,
    32, 27, 3, 9,
    19, 13, 30, 6,
    22, 11, 4, 25,
};

static char L[64];
static char tempL[32];
static char f[32];

static char preS[48];

/*ARGSUSED*/
static void
unlocked_encrypt(char *block, int fake)
{
    int i;
    int t, j, k;
    char *R = &L[32];

    for (j = 0; j < 64; j++)
        L[j] = block[IP[j]-1];
    for (i = 0; i < 16; i++) {
        int index = i * 48;

        for (j = 0; j < 32; j++)
            tempL[j] = R[j];
        for (j = 0; j < 48; j++)
            preS[j] = R[E[j]-1] ^ *(KS+index+j);
        for (j = 0; j < 8; j++) {
            t = 6 * j;
            k = S[j][(preS[t+0]<<5) +
                (preS[t+1]<<3) +
                (preS[t+2]<<2) +
                (preS[t+3]<<1) +
                (preS[t+4]<<0) +
                (preS[t+5]<<4)];
            t = 4*j;
            f[t+0] = (k>>3)&01;
            f[t+1] = (k>>2)&01;
            f[t+2] = (k>>1)&01;
            f[t+3] = (k>>0)&01;
        }
        for (j = 0; j < 32; j++)
            R[j] = L[j] ^ f[P[j]-1];
        for (j = 0; j < 32; j++)
            L[j] = tempL[j];
    }
    for (j = 0; j < 32; j++) {
        t = L[j];
        L[j] = R[j];
        R[j] = (char)t;
    }
    for (j = 0; j < 64; j++)
        block[j] = L[FP[j]-1];
}

char *
_unix_crypt(const char *pw, const char *salt, char *iobuf)
{
    int c, i, j;
    char temp;
    char *block;

    block = iobuf + 16;

    if (iobuf == 0) {
        errno = ENOMEM;
        return (NULL);
    }
    if (allocate_KS() != 0)
        return (NULL);
    lmutex_lock(&crypt_lock);
    for (i = 0; i < 66; i++)
        block[i] = 0;
    for (i = 0; (c = *pw) != '\0' && i < 64; pw++) {
        for (j = 0; j < 7; j++, i++)
            block[i] = (c>>(6-j)) & 01;
        i++;
    }

    unlocked_setkey(block);

    for (i = 0; i < 66; i++)
        block[i] = 0;

    for (i = 0; i < 2; i++) {
        c = *salt++;
        iobuf[i] = (char)c;
        if (c > 'Z')
            c -= 6;
        if (c > '9')
            c -= 7;
        c -= '.';
        for (j = 0; j < 6; j++) {
            if ((c>>j) & 01) {
                temp = E[6*i+j];
                E[6*i+j] = E[6*i+j+24];
                E[6*i+j+24] = temp;
            }
        }
    }

    for (i = 0; i < 25; i++)
        unlocked_encrypt(block, 0);

    lmutex_unlock(&crypt_lock);
    for (i = 0; i < 11; i++) {
        c = 0;
        for (j = 0; j < 6; j++) {
            c <<= 1;
            c |= block[6*i+j];
        }
        c += '.';
        if (c > '9')
            c += 7;
        if (c > 'Z')
            c += 6;
        iobuf[i+2] = (char)c;
    }
    iobuf[i+2] = 0;
    if (iobuf[1] == 0)
        iobuf[1] = iobuf[0];
    return (iobuf);
}


/*ARGSUSED*/
void
encrypt(char *block, int fake)
{
    if (fake != 0) {
        errno = ENOSYS;
        return;
    }
    if (allocate_KS() != 0)
        return;
    lmutex_lock(&crypt_lock);
    unlocked_encrypt(block, fake);
    lmutex_unlock(&crypt_lock);
}


void
setkey(const char *key)
{
    if (allocate_KS() != 0)
        return;
    lmutex_lock(&crypt_lock);
    unlocked_setkey(key);
    lmutex_unlock(&crypt_lock);
}