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/***************************************************************************
* Copyright (c) 2009-2010 Open Information Security Foundation
* Copyright (c) 2010-2013 Qualys, Inc.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are
* met:
*
* - Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* - 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.
* - Neither the name of the Qualys, Inc. 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 COPYRIGHT HOLDERS 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 COPYRIGHT
* HOLDER 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.
***************************************************************************/
/**
* @file
* @author Ivan Ristic <ivanr@webkreator.com>
*/
#include "htp_config_auto.h"
#include "htp_private.h"
/**
* Determines protocol number from a textual representation (i.e., "HTTP/1.1"). This
* function will only understand a properly formatted protocol information. It does
* not try to be flexible.
*
* @param[in] protocol
* @return Protocol version or PROTOCOL_UNKNOWN.
*/
int htp_parse_protocol(bstr *protocol) {
if (protocol == NULL) return HTP_PROTOCOL_INVALID;
// TODO This function uses a very strict approach to parsing, whereas
// browsers will typically be more flexible, allowing whitespace
// before and after the forward slash, as well as allowing leading
// zeroes in the numbers. We should be able to parse such malformed
// content correctly (but emit a warning).
if (bstr_len(protocol) == 8) {
unsigned char *ptr = bstr_ptr(protocol);
if ((ptr[0] == 'H') && (ptr[1] == 'T') && (ptr[2] == 'T') && (ptr[3] == 'P')
&& (ptr[4] == '/') && (ptr[6] == '.')) {
// Check the version numbers
if (ptr[5] == '0') {
if (ptr[7] == '9') {
return HTP_PROTOCOL_0_9;
}
} else if (ptr[5] == '1') {
if (ptr[7] == '0') {
return HTP_PROTOCOL_1_0;
} else if (ptr[7] == '1') {
return HTP_PROTOCOL_1_1;
}
}
}
}
return HTP_PROTOCOL_INVALID;
}
/**
* Determines the numerical value of a response status given as a string.
*
* @param[in] status
* @return Status code on success, or HTP_STATUS_INVALID on error.
*/
int htp_parse_status(bstr *status) {
int64_t r = htp_parse_positive_integer_whitespace((unsigned char *) bstr_ptr(status), bstr_len(status), 10);
if (r >= HTP_VALID_STATUS_MIN && r <= HTP_VALID_STATUS_MAX) {
return (int)r;
} else {
return HTP_STATUS_INVALID;
}
}
/**
* Parses Digest Authorization request header.
*
* @param[in] connp
* @param[in] auth_header
*/
int htp_parse_authorization_digest(htp_connp_t *connp, htp_header_t *auth_header) {
// Extract the username
int i = bstr_index_of_c(auth_header->value, "username=");
if (i == -1) return HTP_DECLINED;
unsigned char *data = bstr_ptr(auth_header->value);
size_t len = bstr_len(auth_header->value);
size_t pos = i + 9;
// Ignore whitespace
while ((pos < len) && (isspace((int) data[pos]))) pos++;
if (pos == len) return HTP_DECLINED;
if (data[pos] != '"') return HTP_DECLINED;
return htp_extract_quoted_string_as_bstr(data + pos, len - pos, &(connp->in_tx->request_auth_username), NULL);
}
/**
* Parses Basic Authorization request header.
*
* @param[in] connp
* @param[in] auth_header
*/
int htp_parse_authorization_basic(htp_connp_t *connp, htp_header_t *auth_header) {
unsigned char *data = bstr_ptr(auth_header->value);
size_t len = bstr_len(auth_header->value);
size_t pos = 5;
// Ignore whitespace
while ((pos < len) && (isspace((int) data[pos]))) pos++;
if (pos == len) return HTP_DECLINED;
// Decode base64-encoded data
bstr *decoded = htp_base64_decode_mem(data + pos, len - pos);
if (decoded == NULL) return HTP_ERROR;
// Now extract the username and password
int i = bstr_index_of_c(decoded, ":");
if (i == -1) {
bstr_free(decoded);
return HTP_DECLINED;
}
connp->in_tx->request_auth_username = bstr_dup_ex(decoded, 0, i);
if (connp->in_tx->request_auth_username == NULL) {
bstr_free(decoded);
return HTP_ERROR;
}
connp->in_tx->request_auth_password = bstr_dup_ex(decoded, i + 1, bstr_len(decoded) - i - 1);
if (connp->in_tx->request_auth_password == NULL) {
bstr_free(decoded);
bstr_free(connp->in_tx->request_auth_username);
return HTP_ERROR;
}
bstr_free(decoded);
return HTP_OK;
}
/**
* Parses Bearer Authorization request header.
*
* @param[in] connp
* @param[in] auth_header
*/
int htp_parse_authorization_bearer(htp_connp_t *connp, htp_header_t *auth_header) {
unsigned char *data = bstr_ptr(auth_header->value);
size_t len = bstr_len(auth_header->value);
size_t pos = 6;
// Ignore whitespace
while ((pos < len) && (isspace((int) data[pos]))) pos++;
if (pos == len) return HTP_DECLINED;
// There is nothing much else to check with Bearer auth so we just return
return HTP_OK;
}
/**
* Parses Authorization request header.
*
* @param[in] connp
*/
int htp_parse_authorization(htp_connp_t *connp) {
htp_header_t *auth_header = htp_table_get_c(connp->in_tx->request_headers, "authorization");
if (auth_header == NULL) {
connp->in_tx->request_auth_type = HTP_AUTH_NONE;
return HTP_OK;
}
// TODO Need a flag to raise when failing to parse authentication headers.
if (bstr_begins_with_c_nocase(auth_header->value, "basic")) {
// Basic authentication
connp->in_tx->request_auth_type = HTP_AUTH_BASIC;
return htp_parse_authorization_basic(connp, auth_header);
} else if (bstr_begins_with_c_nocase(auth_header->value, "digest")) {
// Digest authentication
connp->in_tx->request_auth_type = HTP_AUTH_DIGEST;
return htp_parse_authorization_digest(connp, auth_header);
} else if (bstr_begins_with_c_nocase(auth_header->value, "bearer")) {
// OAuth Bearer authentication
connp->in_tx->request_auth_type = HTP_AUTH_BEARER;
return htp_parse_authorization_bearer(connp, auth_header);
} else {
// Unrecognized authentication method
connp->in_tx->request_auth_type = HTP_AUTH_UNRECOGNIZED;
}
return HTP_OK;
}
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