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/*
* Copyright (C) 2000,2001,2002,2003 Nikos Mavroyanopoulos
*
* This file is part of GNUTLS.
*
* The GNUTLS library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*
*/
#include <gnutls_int.h>
#include <gnutls_errors.h>
#include <gnutls_alert.h>
#include <gnutls_record.h>
#include <debug.h>
typedef struct {
gnutls_alert_description alert;
const char *desc;
} gnutls_alert_entry;
static const gnutls_alert_entry sup_alerts[] = {
{ GNUTLS_A_CLOSE_NOTIFY, "Close notify" },
{ GNUTLS_A_UNEXPECTED_MESSAGE, "Unexpected message" },
{ GNUTLS_A_BAD_RECORD_MAC, "Bad record MAC" },
{ GNUTLS_A_DECRYPTION_FAILED, "Decryption failed" },
{ GNUTLS_A_RECORD_OVERFLOW, "Record overflow" },
{ GNUTLS_A_DECOMPRESSION_FAILURE, "Decompression failed" },
{ GNUTLS_A_HANDSHAKE_FAILURE, "Handshake failed" },
{ GNUTLS_A_BAD_CERTIFICATE, "Certificate is bad" },
{ GNUTLS_A_UNSUPPORTED_CERTIFICATE, "Certificate is not supported" },
{ GNUTLS_A_CERTIFICATE_REVOKED, "Certificate was revoked" },
{ GNUTLS_A_CERTIFICATE_EXPIRED, "Certificate is expired" },
{ GNUTLS_A_CERTIFICATE_UNKNOWN, "Unknown certificate" },
{ GNUTLS_A_ILLEGAL_PARAMETER, "Illegal parameter" },
{ GNUTLS_A_UNKNOWN_CA, "CA is unknown" },
{ GNUTLS_A_ACCESS_DENIED, "Access was denied" },
{ GNUTLS_A_DECODE_ERROR, "Decode error" },
{ GNUTLS_A_DECRYPT_ERROR, "Decrypt error" },
{ GNUTLS_A_EXPORT_RESTRICTION, "Export restriction" },
{ GNUTLS_A_PROTOCOL_VERSION, "Error in protocol version" },
{ GNUTLS_A_INSUFFICIENT_SECURITY,"Insufficient security" },
{ GNUTLS_A_USER_CANCELED, "User canceled" },
{ GNUTLS_A_INTERNAL_ERROR, "Internal error" },
{ GNUTLS_A_NO_RENEGOTIATION, "No renegotiation is allowed" },
{ GNUTLS_A_CERTIFICATE_UNOBTAINABLE, "Could not retrieve the specified certificate" },
{ GNUTLS_A_UNSUPPORTED_EXTENSION, "An unsupported extension was sent" },
{ GNUTLS_A_UNRECOGNIZED_NAME, "The server name sent was not recognized" },
{0, NULL}
};
#define GNUTLS_ALERT_LOOP(b) \
const gnutls_alert_entry *p; \
for(p = sup_alerts; p->desc != NULL; p++) { b ; }
#define GNUTLS_ALERT_ID_LOOP(a) \
GNUTLS_ALERT_LOOP( if(p->alert == alert) { a; break; })
/**
* gnutls_alert_get_name - Returns a string describing the alert number given
* @alert: is an alert number &gnutls_session structure.
*
* Returns a string that describes the given alert number.
* See. gnutls_alert_get().
*
**/
const char* gnutls_alert_get_name( gnutls_alert_level alert) {
const char* ret = NULL;
GNUTLS_ALERT_ID_LOOP( ret = p->desc);
return ret;
}
/**
* gnutls_alert_send - This function sends an alert message to the peer
* @session: is a &gnutls_session structure.
* @level: is the level of the alert
* @desc: is the alert description
*
* This function will send an alert to the peer in order to inform
* him of something important (eg. his Certificate could not be verified).
* If the alert level is Fatal then the peer is expected to close the
* connection, otherwise he may ignore the alert and continue.
* Returns 0 on success.
*
**/
int gnutls_alert_send( gnutls_session session, gnutls_alert_level level, gnutls_alert_description desc)
{
uint8 data[2];
int ret;
data[0] = (uint8) level;
data[1] = (uint8) desc;
_gnutls_record_log( "REC: Sending Alert[%d|%d] - %s\n", data[0], data[1], gnutls_alert_get_name((int)data[1]));
if ( (ret = _gnutls_send_int( session, GNUTLS_ALERT, -1, data, 2)) >= 0)
return 0;
else
return ret;
}
/**
* gnutls_error_to_alert - This function returns an alert code based on the given error code
* @err: is a negative integer
* @level: the alert level will be stored there
*
* Returns an alert depending on the error code returned by a gnutls
* function. All alerts sent by this function should be considered fatal.
* The only exception is when err == GNUTLS_E_REHANDSHAKE, where a warning
* alert should be sent to the peer indicating that no renegotiation will
* be performed.
*
* If the return value is GNUTLS_E_INVALID_REQUEST, then there was no
* mapping to an alert.
*
**/
int gnutls_error_to_alert( int err, int* level)
{
int ret = GNUTLS_E_INVALID_REQUEST;
int _level = -1;
switch (err) { /* send appropriate alert */
case GNUTLS_E_DECRYPTION_FAILED:
/* GNUTLS_A_DECRYPTION_FAILED is not sent, because
* it is not defined in SSL3. Note that we must
* not distinguish Decryption failures from mac
* check failures, due to the possibility of some
* attacks.
*/
ret = GNUTLS_A_BAD_RECORD_MAC;
_level = GNUTLS_AL_FATAL;
break;
case GNUTLS_E_EMPTY_SRP_USERNAME:
/* FIXME: needs to be changed
*/
ret = GNUTLS_A_ACCESS_DENIED;
_level = GNUTLS_AL_FATAL;
break;
case GNUTLS_E_DECOMPRESSION_FAILED:
ret = GNUTLS_A_DECOMPRESSION_FAILURE;
_level = GNUTLS_AL_FATAL;
break;
case GNUTLS_E_RECEIVED_ILLEGAL_PARAMETER:
case GNUTLS_E_ILLEGAL_SRP_USERNAME:
ret = GNUTLS_A_ILLEGAL_PARAMETER;
_level = GNUTLS_AL_FATAL;
break;
case GNUTLS_E_ASN1_ELEMENT_NOT_FOUND:
case GNUTLS_E_ASN1_IDENTIFIER_NOT_FOUND:
case GNUTLS_E_ASN1_DER_ERROR:
case GNUTLS_E_ASN1_VALUE_NOT_FOUND:
case GNUTLS_E_ASN1_GENERIC_ERROR:
case GNUTLS_E_ASN1_VALUE_NOT_VALID:
case GNUTLS_E_ASN1_TAG_ERROR:
case GNUTLS_E_ASN1_TAG_IMPLICIT:
case GNUTLS_E_ASN1_TYPE_ANY_ERROR:
case GNUTLS_E_ASN1_SYNTAX_ERROR:
case GNUTLS_E_ASN1_DER_OVERFLOW:
case GNUTLS_E_NO_CERTIFICATE_FOUND:
ret = GNUTLS_A_BAD_CERTIFICATE;
_level = GNUTLS_AL_FATAL;
break;
case GNUTLS_E_UNKNOWN_CIPHER_SUITE:
case GNUTLS_E_UNKNOWN_COMPRESSION_ALGORITHM:
case GNUTLS_E_RECEIVED_ILLEGAL_EXTENSION:
case GNUTLS_E_INSUFICIENT_CREDENTIALS:
case GNUTLS_E_NO_CIPHER_SUITES:
case GNUTLS_E_NO_COMPRESSION_ALGORITHMS:
ret = GNUTLS_A_HANDSHAKE_FAILURE;
_level = GNUTLS_AL_FATAL;
break;
case GNUTLS_E_UNEXPECTED_PACKET:
ret = GNUTLS_A_UNEXPECTED_MESSAGE;
_level = GNUTLS_AL_FATAL;
break;
case GNUTLS_E_REHANDSHAKE:
ret = GNUTLS_A_NO_RENEGOTIATION;
_level = GNUTLS_AL_WARNING;
break;
case GNUTLS_E_UNSUPPORTED_VERSION_PACKET:
ret = GNUTLS_A_PROTOCOL_VERSION;
_level = GNUTLS_AL_FATAL;
break;
case GNUTLS_E_UNSUPPORTED_CERTIFICATE_TYPE:
ret = GNUTLS_A_UNSUPPORTED_CERTIFICATE;
_level = GNUTLS_AL_FATAL;
break;
case GNUTLS_E_UNEXPECTED_PACKET_LENGTH:
ret = GNUTLS_A_RECORD_OVERFLOW;
_level = GNUTLS_AL_FATAL;
break;
case GNUTLS_E_INTERNAL_ERROR:
case GNUTLS_E_NO_TEMPORARY_DH_PARAMS:
case GNUTLS_E_NO_TEMPORARY_RSA_PARAMS:
ret = GNUTLS_A_INTERNAL_ERROR;
_level = GNUTLS_AL_FATAL;
break;
case GNUTLS_E_OPENPGP_GETKEY_FAILED:
ret = GNUTLS_A_CERTIFICATE_UNOBTAINABLE;
_level = GNUTLS_AL_FATAL;
break;
case GNUTLS_E_DH_PRIME_UNACCEPTABLE:
ret = GNUTLS_A_INSUFFICIENT_SECURITY;
_level = GNUTLS_AL_FATAL;
break;
}
if (level != NULL) *level = _level;
return ret;
}
/* Sends the appropriate alert, depending
* on the error message.
*/
/**
* gnutls_alert_send_appropriate - This function sends an alert to the peer depending on the error code
* @session: is a &gnutls_session structure.
* @err: is an integer
*
* Sends an alert to the peer depending on the error code returned by a gnutls
* function. This function will call gnutls_error_to_alert() to determine
* the appropriate alert to send.
*
* This function may also return GNUTLS_E_AGAIN, or GNUTLS_E_INTERRUPTED.
*
* If the return value is GNUTLS_E_INVALID_REQUEST, then no alert has
* been sent to the peer.
*
**/
int gnutls_alert_send_appropriate( gnutls_session session, int err) {
int alert;
int level;
alert = gnutls_error_to_alert( err, &level);
if (alert < 0) {
return alert;
}
return gnutls_alert_send( session, level, alert);
}
/**
* gnutls_alert_get - Returns the last alert number received.
* @session: is a &gnutls_session structure.
*
* Returns the last alert number received. This function
* should be called if GNUTLS_E_WARNING_ALERT_RECEIVED or
* GNUTLS_E_FATAL_ALERT_RECEIVED has been returned by a gnutls function.
* The peer may send alerts if he thinks some things were not
* right. Check gnutls.h for the available alert descriptions.
**/
gnutls_alert_description gnutls_alert_get( gnutls_session session) {
return session->internals.last_alert;
}
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