cmd/keyserv/keylogin.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 2006 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */

/*  Copyright (c) 1984, 1986, 1987, 1988, 1989 AT&T */
/*    All Rights Reserved   */

/*
 * University Copyright- Copyright (c) 1982, 1986, 1988
 * The Regents of the University of California
 * All Rights Reserved
 *
 * University Acknowledgment- Portions of this document are derived from
 * software developed by the University of California, Berkeley, and its
 * contributors.
 */

#pragma ident   "%Z%%M% %I% %E% SMI"

/*
 * Set secret key on local machine
 */
#include <stdio.h>
#include <rpc/rpc.h>
#include <rpc/key_prot.h>
#include <nfs/nfs.h>                /* to revoke existing creds */
#include <nfs/nfssys.h>
#include <string.h>
#include <rpcsvc/nis_dhext.h>

#define ROOTKEY_FILE "/etc/.rootkey"
#define ROOTKEY_FILE_BACKUP "/etc/.rootkey.bak"
/* Should last until 16384-bit DH keys */
#define MAXROOTKEY_LINE_LEN 4224
#define MAXROOTKEY_LEN      4096

extern int key_setnet_g();

static void logout_curr_key();
static int mkrootkey;

static char *sec_domain = NULL;
static char local_domain[MAXNETNAMELEN + 1];

/*
 * fgets is broken in that if it reads a NUL character it will always return
 * EOF.  This replacement can deal with NULs
 */
static char *
fgets_ignorenul(char *s, int n, FILE *stream)
{
    int fildes = fileno(stream);
    int i = 0;
    int rs = 0;
    char c;

    if (fildes < 0)
        return (NULL);

    while (i < n - 1) {
        rs = read(fildes, &c, 1);
        switch (rs) {
        case 1:
            break;
        case 0:
            /* EOF */
            if (i > 0)
                s[i] = '\0';
            return (NULL);
            break;
        default:
            return (NULL);
        }
        switch (c) {
        case '\0':
            break;
        case '\n':
            s[i] = c;
            s[++i] = '\0';
            return (s);
        default:
        if (c != '\0')
            s[i++] = c;
        }
    }
    s[i] = '\0';
    return (s);
}


/* write unencrypted secret key into root key file */
static void
write_rootkey(char *secret, char *flavor, keylen_t keylen, algtype_t algtype)
{
    char        line[MAXROOTKEY_LINE_LEN];
    char        keyent[MAXROOTKEY_LEN];
    algtype_t   atent;
    int     rootfd, bakfd, hexkeybytes;
    bool_t      lineone = TRUE;
    bool_t      gotit = FALSE;
    FILE        *rootfile, *bakfile;

    unlink(ROOTKEY_FILE_BACKUP);
    if ((rename(ROOTKEY_FILE, ROOTKEY_FILE_BACKUP)) < 0) {
        if ((bakfd = creat(ROOTKEY_FILE_BACKUP, 0600)) < 0) {
            perror("Could not create /etc/.rootkey.bak");
            goto rootkey_err;
        }
        close(bakfd);
    }

    if ((rootfd = open(ROOTKEY_FILE, O_WRONLY+O_CREAT, 0600)) < 0) {
        perror("Could not open /etc/.rootkey for writing");
        fprintf(stderr,
            "Attempting to restore original /etc/.rootkey\n");
        (void) rename(ROOTKEY_FILE_BACKUP, ROOTKEY_FILE);
        goto rootkey_err;
    }
    if (!(rootfile = fdopen(rootfd, "w"))) {
        perror("Could not open /etc/.rootkey for writing");
        fprintf(stderr,
            "Attempting to restore original /etc/.rootkey\n");
        close(rootfd);
        unlink(ROOTKEY_FILE);
        rename(ROOTKEY_FILE_BACKUP, ROOTKEY_FILE);
        goto rootkey_err;
    }
    if (!(bakfile = fopen(ROOTKEY_FILE_BACKUP, "r"))) {
        perror("Could not open /etc/.rootkey.bak for reading");
        fprintf(stderr,
            "Attempting to restore original /etc/.rootkey\n");
        (void) fclose(rootfile);
        unlink(ROOTKEY_FILE);
        rename(ROOTKEY_FILE_BACKUP, ROOTKEY_FILE);
        goto rootkey_err;
    }

    hexkeybytes = ((keylen + 7) / 8) * 2;

    while (fgets_ignorenul(line, MAXROOTKEY_LINE_LEN, bakfile)) {
        if (sscanf(line, "%s %d", keyent, &atent) < 2) {
            /*
             * No encryption algorithm found in the file
             * (atent) so default to DES.
             */
            atent = AUTH_DES_ALGTYPE;
        }
        /*
         * 192-bit keys always go on the first line
         */
        if (lineone) {
            lineone = FALSE;
            if (keylen == 192) {
                gotit = TRUE;
                fprintf(rootfile, "%s\n", secret);
            } else
                fprintf(rootfile, "%s", line);
            (void) fflush(rootfile);
        } else {
            if ((strlen(keyent) == hexkeybytes) &&
                (atent == algtype)) {
                /*
                 * Silently remove lines with the same
                 * keylen/algtype
                 */
                if (gotit)
                    continue;
                else
                    gotit = TRUE;

                fprintf(rootfile, "%s %d\n", secret, algtype);
            } else
                fprintf(rootfile, "%s", line);
            (void) fflush(rootfile);
        }
    }

    /* Append key to rootkey file */
    if (!gotit) {
        if (keylen == 192)
            fprintf(rootfile, "%s\n", secret);
        else {
            if (lineone)
                fprintf(rootfile, "\n");
            fprintf(rootfile, "%s %d\n", secret, algtype);
        }
    }
    (void) fflush(rootfile);
    fclose(rootfile);
    fclose(bakfile);
    unlink(ROOTKEY_FILE_BACKUP);
    if (keylen == 192)
        fprintf(stderr, "Wrote secret key into %s\n", ROOTKEY_FILE);
    else
        fprintf(stderr, "Wrote %s key into %s\n", flavor,
            ROOTKEY_FILE);
    return;

rootkey_err:
    fprintf(stderr, "WARNING: Could not write %s key to /etc/.rootkey\n",
        flavor);
}

/* Perform AUTH_DES keylogin */
static int
oldkeylogin(char *fullname, char *pass)
{
    char            secret[HEXKEYBYTES+1];
    struct key_netstarg netst;

        if (getsecretkey(fullname, secret, pass) == 0) {
            fprintf(stderr, "Could not find %s's secret key\n",
                fullname);
            if (sec_domain && *sec_domain &&
                strcasecmp(sec_domain, local_domain)) {
                fprintf(stderr,
"The system default domain '%s' is different from the Secure RPC\n\
domain %s where the key is stored.  The Secure RPC domainname is\n\
defined by the directory object stored in the /var/nis/NIS_COLD_START file.\n\
If you need to change this Secure RPC domainname, please use the nisinit(1M)\n\
command with the `-k` option.\n", local_domain, sec_domain);
            } else {
                fprintf(stderr,
        "Make sure the secret key is stored in domain %s\n",
                local_domain);
            }
            return (1);
        }

        if (secret[0] == 0) {
            fprintf(stderr, "Password incorrect for %s\n",
                fullname);
            return (1);
        }
        /* revoke any existing (lingering) credentials... */
        logout_curr_key();

        memcpy(netst.st_priv_key, secret, HEXKEYBYTES);
        memset(secret, 0, HEXKEYBYTES);

        netst.st_pub_key[0] = 0;
        netst.st_netname = strdup(fullname);

        /* do actual key login */
        if (key_setnet(&netst) < 0) {
            fprintf(stderr, "Could not set %s's secret key\n",
                fullname);
            fprintf(stderr, "May be the keyserv is down?\n");
            if (mkrootkey == 0)   /* nothing else to do */
                return (1);
        }

        /* write unencrypted secret key into root key file */
        if (mkrootkey)
            write_rootkey(netst.st_priv_key, "des", 192, 0);

        return (0);
}

/*
 * Revokes the existing credentials for Secure-RPC and Secure-NFS.
 * This should only be called if the user entered the correct password;
 * sorta like the way "su" doesn't force a login if you enter the wrong
 * password.
 */

static void
logout_curr_key()
{
    static char     secret[HEXKEYBYTES + 1];
    struct nfs_revauth_args nra;

    /*
     * try to revoke the existing key/credentials, assuming
     * one exists.  this will effectively mark "stale" any
     * cached credientials...
     */
    if (key_setsecret(secret) < 0) {
        return;
    }

    /*
     * it looks like a credential already existed, so try and
     * revoke any lingering Secure-NFS privledges.
     */

    nra.authtype = AUTH_DES;
    nra.uid = getuid();

    (void) _nfssys(NFS_REVAUTH, &nra);
}

void
usage(cmd)
    char *cmd;
{
    fprintf(stderr, "usage: %s [-r]\n", cmd);
    exit(1);
}


int
main(int argc, char *argv[])
{
    char        secret[4096];
    char        fullname[MAXNETNAMELEN + 1];
    char        *getpass();
    char        *pass;
    int     i = 0;
    mechanism_t **mechlist;

    if (argc == 1)
        mkrootkey = 0;
    else if (argc == 2 && (strcmp(argv[1], "-r") == 0)) {
        if (geteuid() != 0) {
            fprintf(stderr, "Must be root to use -r option.\n");
            exit(1);
        }
        mkrootkey = 1;
    } else
        usage(argv[0]);

    if (getnetname(fullname) == 0) {
        fprintf(stderr, "Could not generate netname\n");
        exit(1);
    }
    sec_domain = strdup(strchr(fullname, '@') + 1);
    getdomainname(local_domain, MAXNETNAMELEN);

    if (!(pass = getpass("Password:")))
        exit(1);

    if (mechlist = __nis_get_mechanisms(FALSE)) {
        while (mechlist[i]) {
            char        *alias;

            if (AUTH_DES_COMPAT_CHK(mechlist[i])) {
                (void) oldkeylogin(fullname, pass);
                i++;
                continue;
            }

            if (VALID_ALIAS(mechlist[i]->alias))
                alias = mechlist[i]->alias;
            else
                alias = "";

            if (getsecretkey_g(fullname, mechlist[i]->keylen,
                        mechlist[i]->algtype, secret,
                        (((mechlist[i]->keylen / 7) +
                        8) * 2) + 1, pass) == 0) {
                fprintf(stderr,
                "WARNING: Could not find %s's %s secret key\n",
                    fullname, alias);
                i++;
                continue;
            }

            if (secret[0] == 0) {
                fprintf(stderr,
                    "Password incorrect for %s's %s key.\n",
                    fullname, alias);
                i++;
                continue;
            }

            if (key_setnet_g(fullname, secret,
                        mechlist[i]->keylen, NULL, 0,
                        mechlist[i]->algtype) < 0) {
                fprintf(stderr,
                "Could not set %s's %s secret key\n",
                    fullname, alias);
                fprintf(stderr,
                    "May be the keyserv is down?\n");
                exit(1);
            }

            if (mkrootkey)
                write_rootkey(secret, mechlist[i]->alias,
                        mechlist[i]->keylen,
                        mechlist[i]->algtype);
            i++;
        }
    } else
        exit(oldkeylogin(fullname, pass));

    return (0);
}