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/* Copyright (C) 2007-2010 Open Information Security Foundation
*
* You can copy, redistribute or modify this Program under the terms of
* the GNU General Public License version 2 as published by the Free
* Software Foundation.
*
* This program 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 General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* version 2 along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
* 02110-1301, USA.
*/
/**
* \file
*
* \author Pablo Rincon Crespo <pablo.rincon.crespo@gmail.com>
*
* Implements ASN1 decoding (needed for the asn1 keyword)
*/
#ifndef __DECODE_ASN1_H__
#define __DECODE_ASN1_H__
#include <stdio.h>
#include <stdint.h>
#include <stdlib.h>
#include <unistd.h>
#include <inttypes.h>
#include <limits.h>
#include <ctype.h>
#include <string.h>
#define ASN1_MAX_FRAMES 128
/* For future enconding type implementations */
enum {
ASN1_BER_ENC,
ASN1_ENC_UNKNOWN
};
/* Class of tag */
#define ASN1_BER_CLASS_UNIV 0
#define ASN1_BER_CLASS_APP 1
#define ASN1_BER_CLASS_CTX_SPECIFIC 2
#define ASN1_BER_CLASS_PRIV 3
/* For low tag numbers */
#define ASN1_BER_GET_CLASS_TAG(id_octet) \
((id_octet >> 6) & 0x03) /* (8.1.2.2a) */
#define ASN1_BER_IS_CONSTRUCTED(id_octet) \
((id_octet >> 5) & 0x01) /* (8.1.2.5) Constructed Tag */
#define ASN1_BER_IS_PRIMITIVE(id_octet) \
(((id_octet >> 5) & 0x01)?0:1) /* (8.1.2.5) Primitive Tag */
#define ASN1_BER_IS_LOW_TAG(id_octet) \
ASN1_BER_IS_PRIMITIVE(id_octet) /* (8.1.2.5) Is Low Tag
Number */
#define ASN1_BER_GET_LOW_TAG_NUM(id_octet) \
(id_octet & 0x1F) /* (8.1.2.2c) Get LowTag Number */
/* For high tag numbers */
#define ASN1_BER_IS_HIGH_TAG(id_octet) \
((ASN1_BER_GET_LOW_TAG_NUM(id_octet) == 0x1F) && \
ASN1_BER_IS_CONSTRUCTED(id_octet)) /* (8.1.2.4) High Tag Number */
#define ASN1_BER_IS_HIGH_TAG_END(id_octet) \
( !((id_octet >> 7) & 0x01)) /* (8.1.2.4) Is End of Tag Num */
#define ASN1_BER_GET_HIGH_TAG_NUM(id_octet) \
(id_octet & 0x7F) /* (8.1.2.4) Part of High Tag
Number */
#define ASN1_BER_IS_SHORT_LEN(id_octet) \
( !((id_octet >> 7) & 0x01)) /* (8.1.3.3) Is short form */
#define ASN1_BER_GET_SHORT_LEN(id_octet) \
(id_octet & 0x7F) /* (8.1.3.3) length value */
#define ASN1_BER_GET_LONG_LEN_OCTETS(id_octet) \
(id_octet & 0x7F) /* (8.1.3.5) the number of
bytes */
#define ASN1_BER_GET_LONG_LEN(id_octet) \
(id_octet) /* (8.1.3.5) the byte itself*/
#define ASN1_BER_LONG_LEN_HAS_NEXT(id_octet) \
( !((id_octet >> 7) & 0x01)) /* (8.1.3.5) Has next octets
lenght */
#define ASN1_BER_IS_INDEFINITE_LEN(id_octet) \
(id_octet == 0x80) /* (8.1.3.6) Need end-of-ccontent */
#define ASN1_BER_IS_EOC(tmp_iter) (*tmp_iter == 0 && *(tmp_iter + 1) == 0)
/* Return the current node/frame that we are filling */
#define ASN1CTX_CUR_NODE(ac) (ac->asn1_stack[ac->cur_frame])
#define ASN1CTX_GET_NODE(ac, node) (ac->asn1_stack[node])
/* BER Universal tags */
#define ASN1_UNITAG_EOC 0 /* EOC */
#define ASN1_UNITAG_BOOLEAN 1
#define ASN1_UNITAG_INTEGER 2
#define ASN1_UNITAG_BIT_STRING 3
#define ASN1_UNITAG_OCTET_STRING 4
#define ASN1_UNITAG_NULL 5
#define ASN1_UNITAG_OID 6
#define ASN1_UNITAG_OBJECT_DESCRIPTOR 7
#define ASN1_UNITAG_EXTERNAL 8
#define ASN1_UNITAG_REAL 9
#define ASN1_UNITAG_ENUMERATED 10
#define ASN1_UNITAG_EMBEDDED_PDV 11
#define ASN1_UNITAG_UTF8_STRING 12
#define ASN1_UNITAG_RELATIVE_OID 13
#define ASN1_UNITAG_SEQUENCE 16
#define ASN1_UNITAG_SET 17
#define ASN1_UNITAG_NUMERIC_STRING 18
#define ASN1_UNITAG_PRINTABLE_STRING 19
#define ASN1_UNITAG_TELETEX_STRING 20
#define ASN1_UNITAG_VIDEOTEX_STRING 21
#define ASN1_UNITAG_IA5_STRING 22
#define ASN1_UNITAG_UTCTIME 23
#define ASN1_UNITAG_GENERALIZED_TIME 24
#define ASN1_UNITAG_GRAPHIC_STRING 25
#define ASN1_UNITAG_VISIBLE_STRING 26
#define ASN1_UNITAG_GENERAL_STRING 27
#define ASN1_UNITAG_UNIVERSAL_STRING 28
#define ASN1_UNITAG_CHARACTER_STRING 29
#define ASN1_UNITAG_BMP_STRING 30
/* Length form */
#define ASN1_BER_LEN_SHORT 0
#define ASN1_BER_LEN_LONG 1
#define ASN1_BER_LEN_INDEFINITE 2
/* Error events/flags */
#define ASN1_BER_EVENT_ID_TOO_LONG 0x01
#define ASN1_BER_EVENT_INVALID_ID 0x02 /* (8.1.2.4.2c) First subsequent
id val (from bit 7 to 0) Shall
not be 0 */
#define ASN1_BER_EVENT_INVALID_LEN 0x04 /* (8.1.3.2a) we expect a simple
form, or (8.1.3.5c) we got
0xFF, or not enough data */
#define ASN1_BER_EVENT_LEN_TOO_LONG 0x08
#define ASN1_BER_EVENT_EOC_NOT_FOUND 0x10 /* EOC not found */
/* Helper flags */
#define ASN1_NODE_IS_EOC 1
#define ASN1_TAG_TYPE_PRIMITIVE 0
#define ASN1_TAG_TYPE_CONSTRUCTED 1
typedef struct Asn1Len_ {
uint8_t form;
uint32_t len;
uint8_t *ptr;
} Asn1Len;
typedef struct Asn1Id_ {
uint8_t *ptr;
uint8_t class_tag;
uint8_t tag_type;
uint32_t tag_num;
} Asn1Id;
typedef struct Asn1Data_ {
uint8_t *ptr;
uint32_t len;
uint8_t type;
} Asn1Data;
typedef struct Asn1Node_ {
uint8_t *raw_str;
uint8_t data_len;
Asn1Len len;
Asn1Id id;
Asn1Data data;
uint8_t flags;
} Asn1Node;
typedef struct Asn1Ctx_ {
uint8_t *data;
uint8_t *end;
uint16_t len;
uint8_t *iter;
uint16_t cur_frame;
Asn1Node *asn1_stack2[ASN1_MAX_FRAMES];
Asn1Node **asn1_stack;
uint8_t parser_status;
uint8_t ctx_flags;
} Asn1Ctx;
/* Return codes of the decoder */
#define ASN1_PARSER_OK 0x01 /* Everything ok */
#define ASN1_PARSER_ERR 0x02 /* Internal error, fatal error, we can't continue decoding */
/* Status of the parser */
#define ASN1_STATUS_OK 0x00 /* On the road */
#define ASN1_STATUS_INVALID 0x01 /* We found something weird/invalid by the specification, but we can try to continue parsing */
#define ASN1_STATUS_OOB 0x02 /* We don't have enough data or ran out of bounds */
#define ASN1_STATUS_DONE 0x04 /* We have finished cleanly */
void SCPrintByteBin(uint8_t);
Asn1Ctx *SCAsn1CtxNew(void);
void SCAsn1CtxInit(Asn1Ctx *, uint8_t *, uint16_t);
void SCAsn1CtxDestroy(Asn1Ctx *);
uint8_t SCAsn1Decode(Asn1Ctx *, uint16_t);
uint8_t SCAsn1DecodeIdentifier(Asn1Ctx *);
uint8_t SCAsn1DecodeLength(Asn1Ctx *);
uint8_t SCAsn1DecodeContent(Asn1Ctx *);
uint8_t SCAsn1CheckBounds(Asn1Ctx *);
void DecodeAsn1RegisterTests(void);
void SCAsn1LoadConfig();
#endif /* __DECODE_ASN1_H__ */
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