krb5/krb/parse.c

	parse.c revision ba7b222e36bac28710a7f43739283302b617e7f5
/*
 * Copyright 2009 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */

/*
 * lib/krb5/krb/parse.c
 *
 * Copyright 1990,1991,2008 by the Massachusetts Institute of Technology.
 * All Rights Reserved.
 *
 * Export of this software from the United States of America may
 *   require a specific license from the United States Government.
 *   It is the responsibility of any person or organization contemplating
 *   export to obtain such a license before exporting.
 *
 * WITHIN THAT CONSTRAINT, permission to use, copy, modify, and
 * distribute this software and its documentation for any purpose and
 * without fee is hereby granted, provided that the above copyright
 * notice appear in all copies and that both that copyright notice and
 * this permission notice appear in supporting documentation, and that
 * the name of M.I.T. not be used in advertising or publicity pertaining
 * to distribution of the software without specific, written prior
 * permission.  Furthermore if you modify this software you must label
 * your software as modified software and not distribute it in such a
 * fashion that it might be confused with the original M.I.T. software.
 * M.I.T. makes no representations about the suitability of
 * this software for any purpose.  It is provided "as is" without express
 * or implied warranty.
 *
 *
 * krb5_parse_name() routine.
 *
 * Rewritten by Theodore Ts'o to properly handle arbitrary quoted
 * characters in the principal name.
 */


#include "k5-int.h"

/*
 * converts a single-string representation of the name to the
 * multi-part principal format used in the protocols.
 *
 * principal will point to allocated storage which should be freed by
 * the caller (using krb5_free_principal) after use.
 *
 * Conventions:  / is used to separate components.  If @ is present in the
 * string, then the rest of the string after it represents the realm name.
 * Otherwise the local realm name is used.
 *
 * error return:
 *  KRB5_PARSE_MALFORMED    badly formatted string
 *
 * also returns system errors:
 *  ENOMEM  malloc failed/out of memory
 *
 * get_default_realm() is called; it may return other errors.
 */

#define REALM_SEP   '@'
#define COMPONENT_SEP   '/'
#define QUOTECHAR   '\\'

#define FCOMPNUM    10

/*
 * May the fleas of a thousand camels infest the ISO, they who think
 * that arbitrarily large multi-component names are a Good Thing.....
 */
static krb5_error_code
/*LINTED*/
k5_parse_name(krb5_context context, const char *name,
          int flags, krb5_principal *nprincipal)
{
    register const char *cp;
    register char   *q;
    register int    i,c,size;
    int     components = 0;
    const char  *parsed_realm = NULL;
    int     fcompsize[FCOMPNUM];
    unsigned int    realmsize = 0;
#ifndef _KERNEL
    char        *default_realm = NULL;
    int     default_realm_size = 0;
    krb5_error_code retval;
#endif
    char        *tmpdata;
    krb5_principal  principal;
    unsigned int    enterprise = (flags & KRB5_PRINCIPAL_PARSE_ENTERPRISE);
    int     first_at;

    *nprincipal = NULL;

    /*
     * Pass 1.  Find out how many components there are to the name,
     * and get string sizes for the first FCOMPNUM components. For
     * enterprise principal names (UPNs), there is only a single
     * component.
     */
    size = 0;
    /*LINTED*/
    for (i=0,cp = name, first_at = 1; (c = *cp); cp++) {
        if (c == QUOTECHAR) {
            cp++;
            /*LINTED*/
            if (!(c = *cp))
                /*
                 * QUOTECHAR can't be at the last
                 * character of the name!
                 */
                return(KRB5_PARSE_MALFORMED);
            size++;
            continue;
        } else if (c == COMPONENT_SEP && !enterprise) {
            if (parsed_realm)
                /*
                 * Shouldn't see a component separator
                 * after we've parsed out the realm name!
                 */
                return(KRB5_PARSE_MALFORMED);
            if (i < FCOMPNUM) {
                fcompsize[i] = size;
            }
            size = 0;
            i++;
        } else if (c == REALM_SEP && (!enterprise || !first_at)) {
            if (parsed_realm)
                /*
                 * Multiple realm separaters
                 * not allowed; zero-length realms are.
                 */
                return(KRB5_PARSE_MALFORMED);
            parsed_realm = cp + 1;
            if (i < FCOMPNUM) {
                fcompsize[i] = size;
            }
            size = 0;
        } else {
            if (c == REALM_SEP && enterprise && first_at)
                first_at = 0;

            size++;
        }
    }
    if (parsed_realm != NULL)
        realmsize = size;
    else if (i < FCOMPNUM)
        fcompsize[i] = size;
    components = i + 1;
    /*
     * Now, we allocate the principal structure and all of its
     * component pieces
     */
    principal = (krb5_principal)MALLOC(sizeof(krb5_principal_data));
    if (principal == NULL) {
        return(ENOMEM);
    }
    principal->data = (krb5_data *)MALLOC(sizeof(krb5_data) * components);
    if (principal->data == NULL) {
        krb5_xfree_wrap(principal, sizeof(krb5_principal_data));
        return ENOMEM;
    }
    principal->length = components;

    /*
     * If a realm was not found, then use the default realm, unless
     * KRB5_PRINCIPAL_PARSE_NO_REALM was specified in which case the
     * realm will be empty.
     */
#ifndef _KERNEL
    if (!parsed_realm) {
        if (flags & KRB5_PRINCIPAL_PARSE_REQUIRE_REALM) {
        krb5_set_error_message(context, KRB5_PARSE_MALFORMED,
                       "Principal %s is missing required realm", name);
        krb5_xfree_wrap(principal->data, principal->length);
        krb5_xfree_wrap(principal, sizeof(krb5_principal_data));
        return KRB5_PARSE_MALFORMED;
        }
        if (!default_realm && (flags & KRB5_PRINCIPAL_PARSE_NO_REALM) == 0) {
        retval = krb5_get_default_realm(context, &default_realm);
        if (retval) {
            krb5_xfree_wrap(principal->data, principal->length);
            krb5_xfree_wrap(principal, sizeof(krb5_principal_data));
            return(retval);
        }
        default_realm_size = strlen(default_realm);
        }
        realmsize = default_realm_size;
    } else if (flags & KRB5_PRINCIPAL_PARSE_NO_REALM) {
        krb5_set_error_message(context, KRB5_PARSE_MALFORMED,
                  "Principal %s has realm present", name);
        krb5_xfree_wrap(principal->data, principal->length);
        krb5_xfree_wrap(principal, sizeof(krb5_principal_data));
        return KRB5_PARSE_MALFORMED;
    }
#endif

    /*
     * Pass 2.  Happens only if there were more than FCOMPNUM
     * component; if this happens, someone should be shot
     * immediately.  Nevertheless, we will attempt to handle said
     * case..... <martyred sigh>
     */
    if (components >= FCOMPNUM) {
        size = 0;
        parsed_realm = NULL;
        /*LINTED*/
        for (i=0,cp = name; (c = *cp); cp++) {
            if (c == QUOTECHAR) {
                cp++;
                size++;
            } else if (c == COMPONENT_SEP) {
                if (krb5_princ_size(context, principal) > i)
                    krb5_princ_component(context, principal, i)->length = size;
                size = 0;
                i++;
            } else if (c == REALM_SEP) {
                if (krb5_princ_size(context, principal) > i)
                    krb5_princ_component(context, principal, i)->length = size;
                size = 0;
                parsed_realm = cp+1;
            } else
                size++;
        }
        if (parsed_realm)
            krb5_princ_realm(context, principal)->length = size;
        else
            if (krb5_princ_size(context, principal) > i)
                krb5_princ_component(context, principal, i)->length = size;
        if (i + 1 != components) {
#ifndef _KERNEL
#if !defined(_WIN32)
            fprintf(stderr,
                "Programming error in krb5_parse_name!");
#endif
            ASSERT(i + 1 == components);
            abort();
#else
            ASSERT(i + 1 == components);
#endif /* !_KERNEL */

        }
    } else {
        /*
         * If there were fewer than FCOMPSIZE components (the
         * usual case), then just copy the sizes to the
         * principal structure
         */
        for (i=0; i < components; i++)
            krb5_princ_component(context, principal, i)->length = fcompsize[i];
    }
    /*
     * Now, we need to allocate the space for the strings themselves.....
     */
    tmpdata = MALLOC(realmsize + 1);
    if (tmpdata == 0) {
        krb5_xfree_wrap(principal->data, principal->length);
        krb5_xfree_wrap(principal, sizeof(krb5_principal_data));
#ifndef _KERNEL
        krb5_xfree_wrap(default_realm, strlen(default_realm));
#endif
        return ENOMEM;
    }
    krb5_princ_set_realm_length(context, principal, realmsize);
    krb5_princ_set_realm_data(context, principal, tmpdata);
    for (i=0; i < components; i++) {
        char *tmpdata2 =
          MALLOC(krb5_princ_component(context, principal, i)->length + 1);
        if (tmpdata2 == NULL) {
            for (i--; i >= 0; i--)
                krb5_xfree_wrap(krb5_princ_component(context,
                    principal, i)->data,
                                    krb5_princ_component(context,
                                    principal, i)->length + 1);

            krb5_xfree_wrap(krb5_princ_realm(context,
                principal)->data, krb5_princ_realm(context,
                principal)->length + 1);

            krb5_xfree_wrap(principal->data, principal->length);
            krb5_xfree_wrap(principal, sizeof(krb5_principal_data));
#ifndef _KERNEL
            krb5_xfree_wrap(default_realm, strlen(default_realm));
#endif
            return(ENOMEM);
        }
        krb5_princ_component(context, principal, i)->data = tmpdata2;
        krb5_princ_component(context, principal, i)->magic = KV5M_DATA;
    }

    /*
     * Pass 3.  Now we go through the string a *third* time, this
     * time filling in the krb5_principal structure which we just
     * allocated.
     */
    q = krb5_princ_component(context, principal, 0)->data;
    /*LINTED*/
    for (i=0,cp = name, first_at = 1; (c = *cp); cp++) {
        if (c == QUOTECHAR) {
            cp++;
            switch (c = *cp) {
            case 'n':
                *q++ = '\n';
                break;
            case 't':
                *q++ = '\t';
                break;
            case 'b':
                *q++ = '\b';
                break;
            case '0':
                *q++ = '\0';
                break;
            default:
                *q++ = c;
                break;
            }
        } else if (c == COMPONENT_SEP && !enterprise) {
            i++;
            *q++ = '\0';
            q = krb5_princ_component(context, principal, i)->data;
        } else if (c == REALM_SEP && (!enterprise || !first_at)) {
            i++;
            *q++ = '\0';
            q = krb5_princ_realm(context, principal)->data;
        } else {
            if (c == REALM_SEP && enterprise && first_at)
                first_at = 0;

            *q++ = c;
        }
    }
    *q++ = '\0';
    /*LINTED*/
    if (!parsed_realm) {
#ifndef _KERNEL

        if (flags & KRB5_PRINCIPAL_PARSE_NO_REALM)
            (krb5_princ_realm(context, principal)->data)[0] = '\0';
        else
            strlcpy(krb5_princ_realm(context, principal)->data, default_realm, realmsize+1);
#endif
    }
    /*
     * Alright, we're done.  Now stuff a pointer to this monstrosity
     * into the return variable, and let's get out of here.
     */
    if (enterprise)
        krb5_princ_type(context, principal) = KRB5_NT_ENTERPRISE_PRINCIPAL;
    else
        krb5_princ_type(context, principal) = KRB5_NT_PRINCIPAL;
    principal->magic = KV5M_PRINCIPAL;
    principal->realm.magic = KV5M_DATA;
    *nprincipal = principal;

#ifndef _KERNEL
    if (default_realm != NULL)
        krb5_xfree_wrap(default_realm, strlen(default_realm));
#endif

    return(0);
}

krb5_error_code KRB5_CALLCONV
krb5_parse_name(krb5_context context, const char *name, krb5_principal *nprincipal)
{
     return k5_parse_name(context, name, 0, nprincipal);
}

krb5_error_code KRB5_CALLCONV
krb5_parse_name_flags(krb5_context context, const char *name,
              int flags, krb5_principal *nprincipal)
{
     return k5_parse_name(context, name, flags, nprincipal);
}