/*
 * Copyright (c) 1997 - 2003 Kungliga Tekniska Högskolan
 * (Royal Institute of Technology, Stockholm, Sweden).
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 *
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * 3. Neither the name of the Institute nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

#include "gsskrb5_locl.h"

static OM_uint32
parse_krb5_name (OM_uint32 *minor_status,
                 krb5_context context,
                 const char *name,
                 gss_name_t *output_name)
{
    krb5_principal princ;
    krb5_error_code kerr;

    kerr = krb5_parse_name (context, name, &princ);

    if (kerr == 0) {
        *output_name = (gss_name_t)princ;
        return GSS_S_COMPLETE;
    }
    *minor_status = kerr;

    if (kerr == KRB5_PARSE_ILLCHAR || kerr == KRB5_PARSE_MALFORMED)
        return GSS_S_BAD_NAME;

    return GSS_S_FAILURE;
}

static OM_uint32
import_krb5_name (OM_uint32 *minor_status,
                  krb5_context context,
                  const gss_buffer_t input_name_buffer,
                  gss_name_t *output_name)
{
    OM_uint32 ret;
    char *tmp;

    tmp = malloc (input_name_buffer->length + 1);
    if (tmp == NULL) {
        *minor_status = ENOMEM;
        return GSS_S_FAILURE;
    }
    memcpy (tmp,
            input_name_buffer->value,
            input_name_buffer->length);
    tmp[input_name_buffer->length] = '\0';

    ret = parse_krb5_name(minor_status, context, tmp, output_name);
    free(tmp);

    return ret;
}

OM_uint32
_gsskrb5_canon_name(OM_uint32 *minor_status, krb5_context context,
                    int use_dns, krb5_const_principal sourcename, gss_name_t targetname,
                    krb5_principal *out)
{
    krb5_principal p = (krb5_principal)targetname;
    krb5_error_code ret;
    char *hostname = NULL, *service;

    *minor_status = 0;

    /* If its not a hostname */
    if (krb5_principal_get_type(context, p) != MAGIC_HOSTBASED_NAME_TYPE) {
        ret = krb5_copy_principal(context, p, out);
    } else if (!use_dns) {
        ret = krb5_copy_principal(context, p, out);
        if (ret)
            goto out;
        krb5_principal_set_type(context, *out, KRB5_NT_SRV_HST);
        if (sourcename)
            ret = krb5_principal_set_realm(context, *out, sourcename->realm);
    } else {
        if (p->name.name_string.len == 0)
            return GSS_S_BAD_NAME;
        else if (p->name.name_string.len > 1)
            hostname = p->name.name_string.val[1];

        service = p->name.name_string.val[0];

        ret = krb5_sname_to_principal(context,
                                      hostname,
                                      service,
                                      KRB5_NT_SRV_HST,
                                      out);
    }

 out:
    if (ret) {
        *minor_status = ret;
        return GSS_S_FAILURE;
    }

    return 0;
}


static OM_uint32
import_hostbased_name (OM_uint32 *minor_status,
                       krb5_context context,
                       const gss_buffer_t input_name_buffer,
                       gss_name_t *output_name)
{
    krb5_principal princ = NULL;
    krb5_error_code kerr;
    char *tmp, *p, *host = NULL;

    tmp = malloc (input_name_buffer->length + 1);
    if (tmp == NULL) {
        *minor_status = ENOMEM;
        return GSS_S_FAILURE;
    }
    memcpy (tmp,
            input_name_buffer->value,
            input_name_buffer->length);
    tmp[input_name_buffer->length] = '\0';

    p = strchr (tmp, '@');
    if (p != NULL) {
        *p = '\0';
        host = p + 1;
    }

    kerr = krb5_make_principal(context, &princ, NULL, tmp, host, NULL);
    free (tmp);
    *minor_status = kerr;
    if (kerr == KRB5_PARSE_ILLCHAR || kerr == KRB5_PARSE_MALFORMED)
        return GSS_S_BAD_NAME;
    else if (kerr)
        return GSS_S_FAILURE;

    krb5_principal_set_type(context, princ, MAGIC_HOSTBASED_NAME_TYPE);
    *output_name = (gss_name_t)princ;

    return 0;
}

static OM_uint32
import_export_name (OM_uint32 *minor_status,
                    krb5_context context,
                    const gss_buffer_t input_name_buffer,
                    gss_name_t *output_name)
{
    unsigned char *p;
    uint32_t length;
    OM_uint32 ret;
    char *name;

    if (input_name_buffer->length < 10 + GSS_KRB5_MECHANISM->length)
        return GSS_S_BAD_NAME;

    /* TOK, MECH_OID_LEN, DER(MECH_OID), NAME_LEN, NAME */

    p = input_name_buffer->value;

    if (memcmp(&p[0], "\x04\x01\x00", 3) != 0 ||
        p[3] != GSS_KRB5_MECHANISM->length + 2 ||
        p[4] != 0x06 ||
        p[5] != GSS_KRB5_MECHANISM->length ||
        memcmp(&p[6], GSS_KRB5_MECHANISM->elements,
               GSS_KRB5_MECHANISM->length) != 0)
        return GSS_S_BAD_NAME;

    p += 6 + GSS_KRB5_MECHANISM->length;

    length = p[0] << 24 | p[1] << 16 | p[2] << 8 | p[3];
    p += 4;

    if (length > input_name_buffer->length - 10 - GSS_KRB5_MECHANISM->length)
        return GSS_S_BAD_NAME;

    name = malloc(length + 1);
    if (name == NULL) {
        *minor_status = ENOMEM;
        return GSS_S_FAILURE;
    }
    memcpy(name, p, length);
    name[length] = '\0';

    ret = parse_krb5_name(minor_status, context, name, output_name);
    free(name);

    return ret;
}

OM_uint32 GSSAPI_CALLCONV _gsskrb5_import_name
           (OM_uint32 * minor_status,
            const gss_buffer_t input_name_buffer,
            const gss_OID input_name_type,
            gss_name_t * output_name
           )
{
    krb5_context context;

    *minor_status = 0;
    *output_name = GSS_C_NO_NAME;

    GSSAPI_KRB5_INIT (&context);

    if (gss_oid_equal(input_name_type, GSS_C_NT_HOSTBASED_SERVICE) ||
        gss_oid_equal(input_name_type, GSS_C_NT_HOSTBASED_SERVICE_X))
        return import_hostbased_name (minor_status,
                                      context,
                                      input_name_buffer,
                                      output_name);
    else if (input_name_type == GSS_C_NO_OID
             || gss_oid_equal(input_name_type, GSS_C_NT_USER_NAME)
             || gss_oid_equal(input_name_type, GSS_KRB5_NT_PRINCIPAL_NAME))
        /* default printable syntax */
        return import_krb5_name (minor_status,
                                 context,
                                 input_name_buffer,
                                 output_name);
    else if (gss_oid_equal(input_name_type, GSS_C_NT_EXPORT_NAME)) {
        return import_export_name(minor_status,
                                  context,
                                  input_name_buffer,
                                  output_name);
    } else {
        *minor_status = 0;
        return GSS_S_BAD_NAMETYPE;
    }
}