/*
 * Copyright (c) 1997 - 2005 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 "kadmin_locl.h"
#include <krb5-private.h>

RCSID("$Id: server.c 17611 2006-06-02 22:10:21Z lha $");

static kadm5_ret_t
kadmind_dispatch(void *kadm_handle, krb5_boolean initial,
		 krb5_data *in, krb5_data *out)
{
    kadm5_ret_t ret;
    int32_t cmd, mask, tmp;
    kadm5_server_context *context = kadm_handle;
    char client[128], name[128], name2[128];
    char *op = "";
    krb5_principal princ, princ2;
    kadm5_principal_ent_rec ent;
    char *password, *expression;
    krb5_keyblock *new_keys;
    int n_keys;
    char **princs;
    int n_princs;
    krb5_storage *sp;
    
    krb5_unparse_name_fixed(context->context, context->caller, 
			    client, sizeof(client));
    
    sp = krb5_storage_from_data(in);

    krb5_ret_int32(sp, &cmd);
    switch(cmd){
    case kadm_get:{
	op = "GET";
	ret = krb5_ret_principal(sp, &princ);
	if(ret)
	    goto fail;
	ret = krb5_ret_int32(sp, &mask);
	if(ret){
	    krb5_free_principal(context->context, princ);
	    goto fail;
	}
	krb5_unparse_name_fixed(context->context, princ, name, sizeof(name));
	krb5_warnx(context->context, "%s: %s %s", client, op, name);
	ret = _kadm5_acl_check_permission(context, KADM5_PRIV_GET, princ);
	if(ret){
	    krb5_free_principal(context->context, princ);
	    goto fail;
	}
	ret = kadm5_get_principal(kadm_handle, princ, &ent, mask);
	krb5_storage_free(sp);
	sp = krb5_storage_emem();
	krb5_store_int32(sp, ret);
	if(ret == 0){
	    kadm5_store_principal_ent(sp, &ent);
	    kadm5_free_principal_ent(kadm_handle, &ent);
	}
	krb5_free_principal(context->context, princ);
	break;
    }
    case kadm_delete:{
	op = "DELETE";
	ret = krb5_ret_principal(sp, &princ);
	if(ret)
	    goto fail;
	krb5_unparse_name_fixed(context->context, princ, name, sizeof(name));
	krb5_warnx(context->context, "%s: %s %s", client, op, name);
	ret = _kadm5_acl_check_permission(context, KADM5_PRIV_DELETE, princ);
	if(ret){
	    krb5_free_principal(context->context, princ);
	    goto fail;
	}
	ret = kadm5_delete_principal(kadm_handle, princ);
	krb5_free_principal(context->context, princ);
	krb5_storage_free(sp);
	sp = krb5_storage_emem();
	krb5_store_int32(sp, ret);
	break;
    }
    case kadm_create:{
	op = "CREATE";
	ret = kadm5_ret_principal_ent(sp, &ent);
	if(ret)
	    goto fail;
	ret = krb5_ret_int32(sp, &mask);
	if(ret){
	    kadm5_free_principal_ent(context->context, &ent);
	    goto fail;
	}
	ret = krb5_ret_string(sp, &password);
	if(ret){
	    kadm5_free_principal_ent(context->context, &ent);
	    goto fail;
	}
	krb5_unparse_name_fixed(context->context, ent.principal, 
				name, sizeof(name));
	krb5_warnx(context->context, "%s: %s %s", client, op, name);
	ret = _kadm5_acl_check_permission(context, KADM5_PRIV_ADD,
					  ent.principal);
	if(ret){
	    kadm5_free_principal_ent(context->context, &ent);
	    memset(password, 0, strlen(password));
	    free(password);
	    goto fail;
	}
	ret = kadm5_create_principal(kadm_handle, &ent, 
				     mask, password);
	kadm5_free_principal_ent(kadm_handle, &ent);
	memset(password, 0, strlen(password));
	free(password);
	krb5_storage_free(sp);
	sp = krb5_storage_emem();
	krb5_store_int32(sp, ret);
	break;
    }
    case kadm_modify:{
	op = "MODIFY";
	ret = kadm5_ret_principal_ent(sp, &ent);
	if(ret)
	    goto fail;
	ret = krb5_ret_int32(sp, &mask);
	if(ret){
	    kadm5_free_principal_ent(context, &ent);
	    goto fail;
	}
	krb5_unparse_name_fixed(context->context, ent.principal, 
				name, sizeof(name));
	krb5_warnx(context->context, "%s: %s %s", client, op, name);
	ret = _kadm5_acl_check_permission(context, KADM5_PRIV_MODIFY,
					  ent.principal);
	if(ret){
	    kadm5_free_principal_ent(context, &ent);
	    goto fail;
	}
	ret = kadm5_modify_principal(kadm_handle, &ent, mask);
	kadm5_free_principal_ent(kadm_handle, &ent);
	krb5_storage_free(sp);
	sp = krb5_storage_emem();
	krb5_store_int32(sp, ret);
	break;
    }
    case kadm_rename:{
	op = "RENAME";
	ret = krb5_ret_principal(sp, &princ);
	if(ret)
	    goto fail;
	ret = krb5_ret_principal(sp, &princ2);
	if(ret){
	    krb5_free_principal(context->context, princ);
	    goto fail;
	}
	krb5_unparse_name_fixed(context->context, princ, name, sizeof(name));
	krb5_unparse_name_fixed(context->context, princ2, name2, sizeof(name2));
	krb5_warnx(context->context, "%s: %s %s -> %s", 
		   client, op, name, name2);
	ret = _kadm5_acl_check_permission(context, 
					  KADM5_PRIV_ADD,
					  princ2)
	    || _kadm5_acl_check_permission(context, 
					   KADM5_PRIV_DELETE,
					   princ);
	if(ret){
	    krb5_free_principal(context->context, princ);
	    krb5_free_principal(context->context, princ2);
	    goto fail;
	}
	ret = kadm5_rename_principal(kadm_handle, princ, princ2);
	krb5_free_principal(context->context, princ);
	krb5_free_principal(context->context, princ2);
	krb5_storage_free(sp);
	sp = krb5_storage_emem();
	krb5_store_int32(sp, ret);
	break;
    }
    case kadm_chpass:{
	op = "CHPASS";
	ret = krb5_ret_principal(sp, &princ);
	if(ret)
	    goto fail;
	ret = krb5_ret_string(sp, &password);
	if(ret){
	    krb5_free_principal(context->context, princ);
	    goto fail;
	}
	krb5_unparse_name_fixed(context->context, princ, name, sizeof(name));
	krb5_warnx(context->context, "%s: %s %s", client, op, name);

	/*
	 * The change is allowed if at least one of:

	 * a) it's for the principal him/herself and this was an
	 *    initial ticket, but then, check with the password quality
	 *    function.
	 * b) the user is on the CPW ACL.
	 */

	if (initial
	    && krb5_principal_compare (context->context, context->caller,
				       princ))
	{
	    krb5_data pwd_data;
	    const char *pwd_reason;

	    pwd_data.data = password;
	    pwd_data.length = strlen(password);

	    pwd_reason = kadm5_check_password_quality (context->context,
						       princ, &pwd_data);
	    if (pwd_reason != NULL)
		ret = KADM5_PASS_Q_DICT;
	    else
		ret = 0;
	} else
	    ret = _kadm5_acl_check_permission(context, KADM5_PRIV_CPW, princ);

	if(ret) {
	    krb5_free_principal(context->context, princ);
	    memset(password, 0, strlen(password));
	    free(password);
	    goto fail;
	}
	ret = kadm5_chpass_principal(kadm_handle, princ, password);
	krb5_free_principal(context->context, princ);
	memset(password, 0, strlen(password));
	free(password);
	krb5_storage_free(sp);
	sp = krb5_storage_emem();
	krb5_store_int32(sp, ret);
	break;
    }
    case kadm_chpass_with_key:{
	int i;
	krb5_key_data *key_data;
	int n_key_data;

	op = "CHPASS_WITH_KEY";
	ret = krb5_ret_principal(sp, &princ);
	if(ret)
	    goto fail;
	ret = krb5_ret_int32(sp, &n_key_data);
	if (ret) {
	    krb5_free_principal(context->context, princ);
	    goto fail;
	}
	/* n_key_data will be squeezed into an int16_t below. */
	if (n_key_data < 0 || n_key_data >= 1 << 16 ||
	    n_key_data > UINT_MAX/sizeof(*key_data)) {
	    ret = ERANGE;
	    krb5_free_principal(context->context, princ);
	    goto fail;
	}

	key_data = malloc (n_key_data * sizeof(*key_data));
	if (key_data == NULL) {
	    ret = ENOMEM;
	    krb5_free_principal(context->context, princ);
	    goto fail;
	}

	for (i = 0; i < n_key_data; ++i) {
	    ret = kadm5_ret_key_data (sp, &key_data[i]);
	    if (ret) {
		int16_t dummy = i;

		kadm5_free_key_data (context, &dummy, key_data);
		free (key_data);
		krb5_free_principal(context->context, princ);
		goto fail;
	    }
	}

	krb5_unparse_name_fixed(context->context, princ, name, sizeof(name));
	krb5_warnx(context->context, "%s: %s %s", client, op, name);

	/*
	 * The change is only allowed if the user is on the CPW ACL,
	 * this it to force password quality check on the user.
	 */

	ret = _kadm5_acl_check_permission(context, KADM5_PRIV_CPW, princ);
	if(ret) {
	    int16_t dummy = n_key_data;

	    kadm5_free_key_data (context, &dummy, key_data);
	    free (key_data);
	    krb5_free_principal(context->context, princ);
	    goto fail;
	}
	ret = kadm5_chpass_principal_with_key(kadm_handle, princ,
					      n_key_data, key_data);
	{
	    int16_t dummy = n_key_data;
	    kadm5_free_key_data (context, &dummy, key_data);
	}
	free (key_data);
	krb5_free_principal(context->context, princ);
	krb5_storage_free(sp);
	sp = krb5_storage_emem();
	krb5_store_int32(sp, ret);
	break;
    }
    case kadm_randkey:{
	op = "RANDKEY";
	ret = krb5_ret_principal(sp, &princ);
	if(ret)
	    goto fail;
	krb5_unparse_name_fixed(context->context, princ, name, sizeof(name));
	krb5_warnx(context->context, "%s: %s %s", client, op, name);
	/*
	 * The change is allowed if at least one of:
	 * a) it's for the principal him/herself and this was an initial ticket
	 * b) the user is on the CPW ACL.
	 */

	if (initial
	    && krb5_principal_compare (context->context, context->caller,
				       princ))
	    ret = 0;
	else
	    ret = _kadm5_acl_check_permission(context, KADM5_PRIV_CPW, princ);

	if(ret) {
	    krb5_free_principal(context->context, princ);
	    goto fail;
	}
	ret = kadm5_randkey_principal(kadm_handle, princ, 
				      &new_keys, &n_keys);
	krb5_free_principal(context->context, princ);
	krb5_storage_free(sp);
	sp = krb5_storage_emem();
	krb5_store_int32(sp, ret);
	if(ret == 0){
	    int i;
	    krb5_store_int32(sp, n_keys);
	    for(i = 0; i < n_keys; i++){
		krb5_store_keyblock(sp, new_keys[i]);
		krb5_free_keyblock_contents(context->context, &new_keys[i]);
	    }
	}
	break;
    }
    case kadm_get_privs:{
	uint32_t privs;
	ret = kadm5_get_privs(kadm_handle, &privs);
	krb5_storage_free(sp);
	sp = krb5_storage_emem();
	krb5_store_int32(sp, ret);
	if(ret == 0)
	    krb5_store_uint32(sp, privs);
	break;
    }
    case kadm_get_princs:{
	op = "LIST";
	ret = krb5_ret_int32(sp, &tmp);
	if(ret)
	    goto fail;
	if(tmp){
	    ret = krb5_ret_string(sp, &expression);
	    if(ret)
		goto fail;
	}else
	    expression = NULL;
	krb5_warnx(context->context, "%s: %s %s", client, op,
		   expression ? expression : "*");
	ret = _kadm5_acl_check_permission(context, KADM5_PRIV_LIST, NULL);
	if(ret){
	    free(expression);
	    goto fail;
	}
	ret = kadm5_get_principals(kadm_handle, expression, &princs, &n_princs);
	free(expression);
	krb5_storage_free(sp);
	sp = krb5_storage_emem();
	krb5_store_int32(sp, ret);
	if(ret == 0){
	    int i;
	    krb5_store_int32(sp, n_princs);
	    for(i = 0; i < n_princs; i++)
		krb5_store_string(sp, princs[i]);
	    kadm5_free_name_list(kadm_handle, princs, &n_princs);
	}
	break;
    }
    default:
	krb5_warnx(context->context, "%s: UNKNOWN OP %d", client, cmd);
	krb5_storage_free(sp);
	sp = krb5_storage_emem();
	krb5_store_int32(sp, KADM5_FAILURE);
	break;
    }
    krb5_storage_to_data(sp, out);
    krb5_storage_free(sp);
    return 0;
fail:
    krb5_warn(context->context, ret, "%s", op);
    krb5_storage_seek(sp, 0, SEEK_SET);
    krb5_store_int32(sp, ret);
    krb5_storage_to_data(sp, out);
    krb5_storage_free(sp);
    return 0;
}

static void
v5_loop (krb5_context context,
	 krb5_auth_context ac,
	 krb5_boolean initial,
	 void *kadm_handle,
	 int fd)
{
    krb5_error_code ret;
    krb5_data in, out;

    for (;;) {
	doing_useful_work = 0;
	if(term_flag)
	    exit(0);
	ret = krb5_read_priv_message(context, ac, &fd, &in);
	if(ret == HEIM_ERR_EOF)
	    exit(0);
	if(ret)
	    krb5_err(context, 1, ret, "krb5_read_priv_message");
	doing_useful_work = 1;
	kadmind_dispatch(kadm_handle, initial, &in, &out);
	krb5_data_free(&in);
	ret = krb5_write_priv_message(context, ac, &fd, &out);
	if(ret)
	    krb5_err(context, 1, ret, "krb5_write_priv_message");
    }
}

static krb5_boolean
match_appl_version(const void *data, const char *appl_version)
{
    unsigned minor;
    if(sscanf(appl_version, "KADM0.%u", &minor) != 1)
	return 0;
    *(unsigned*)data = minor;
    return 1;
}

static void
handle_v5(krb5_context context,
	  krb5_auth_context ac,
	  krb5_keytab keytab,
	  int len,
	  int fd)
{
    krb5_error_code ret;
    u_char version[sizeof(KRB5_SENDAUTH_VERSION)];
    krb5_ticket *ticket;
    char *server_name;
    char *client;
    void *kadm_handle;
    ssize_t n;
    krb5_boolean initial;

    unsigned kadm_version;
    kadm5_config_params realm_params;

    if (len != sizeof(KRB5_SENDAUTH_VERSION))
	krb5_errx(context, 1, "bad sendauth len %d", len);
    n = krb5_net_read(context, &fd, version, len);
    if (n < 0)
	krb5_err (context, 1, errno, "reading sendauth version");
    if (n == 0)
	krb5_errx (context, 1, "EOF reading sendauth version");
    if(memcmp(version, KRB5_SENDAUTH_VERSION, len) != 0)
	krb5_errx(context, 1, "bad sendauth version %.8s", version);
	
    ret = krb5_recvauth_match_version(context, &ac, &fd, 
				      match_appl_version, &kadm_version,
				      NULL, KRB5_RECVAUTH_IGNORE_VERSION, 
				      keytab, &ticket);
    if(ret == KRB5_KT_NOTFOUND)
	krb5_errx(context, 1, "krb5_recvauth: key not found");
    if(ret)
	krb5_err(context, 1, ret, "krb5_recvauth");

    ret = krb5_unparse_name (context, ticket->server, &server_name);
    if (ret)
	krb5_err (context, 1, ret, "krb5_unparse_name");

    if (strncmp (server_name, KADM5_ADMIN_SERVICE,
		 strlen(KADM5_ADMIN_SERVICE)) != 0)
	krb5_errx (context, 1, "ticket for strange principal (%s)",
		   server_name);

    free (server_name);

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

    if(kadm_version == 1) {
	krb5_data params;
	ret = krb5_read_priv_message(context, ac, &fd, &params);
	if(ret)
	    krb5_err(context, 1, ret, "krb5_read_priv_message");
	_kadm5_unmarshal_params(context, &params, &realm_params);
    }

    initial = ticket->ticket.flags.initial;
    ret = krb5_unparse_name(context, ticket->client, &client);
    if (ret)
	krb5_err (context, 1, ret, "krb5_unparse_name");
    krb5_free_ticket (context, ticket);
    ret = kadm5_init_with_password_ctx(context, 
				       client, 
				       NULL,
				       KADM5_ADMIN_SERVICE,
				       &realm_params, 
				       0, 0, 
				       &kadm_handle);
    if(ret)
	krb5_err (context, 1, ret, "kadm5_init_with_password_ctx");
    v5_loop (context, ac, initial, kadm_handle, fd);
}

krb5_error_code
kadmind_loop(krb5_context context,
	     krb5_auth_context ac,
	     krb5_keytab keytab, 
	     int fd)
{
    unsigned char tmp[4];
    ssize_t n;
    unsigned long len;

    n = krb5_net_read(context, &fd, tmp, 4);
    if(n == 0)
	exit(0);
    if(n < 0)
	krb5_err(context, 1, errno, "read");
    _krb5_get_int(tmp, &len, 4);
    /* this v4 test could probably also go away */
    if(len > 0xffff && (len & 0xffff) == ('K' << 8) + 'A') {
	unsigned char v4reply[] = { 
	    0x00, 0x0c, 
	    'K', 'Y', 'O', 'U', 'L', 'O', 'S', 'E', 
	    0x95, 0xb7, 0xa7, 0x08 /* KADM_BAD_VER */
	};
	krb5_net_write(context, &fd, v4reply, sizeof(v4reply));
	krb5_errx(context, 1, "packet appears to be version 4");
    } else {
	handle_v5(context, ac, keytab, len, fd);
    }
    return 0;
}
