asn1_ber_bytecode.h

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/* ASN.1 BER/DER/CER parsing state machine internal definitions
 *
 * Copyright (C) 2012 Red Hat, Inc. All Rights Reserved.
 * Written by David Howells ([email protected])
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public Licence
 * as published by the Free Software Foundation; either version
 * 2 of the Licence, or (at your option) any later version.
 */

#ifndef _LINUX_ASN1_BER_BYTECODE_H
#define _LINUX_ASN1_BER_BYTECODE_H

#ifdef __KERNEL__
#include <linux/types.h>
#endif
#include <linux/asn1.h>

typedef int (*asn1_action_t)(void *context,
                 size_t hdrlen, /* In case of ANY type */
                 unsigned char tag, /* In case of ANY type */
                 const void *value, size_t vlen);

struct asn1_decoder {
    const unsigned char *machine;
    size_t machlen;
    const asn1_action_t *actions;
};

enum asn1_opcode {
    /* The tag-matching ops come first and the odd-numbered slots
     * are for OR_SKIP ops.
     */
#define ASN1_OP_MATCH__SKIP       0x01
#define ASN1_OP_MATCH__ACT        0x02
#define ASN1_OP_MATCH__JUMP       0x04
#define ASN1_OP_MATCH__ANY        0x08
#define ASN1_OP_MATCH__COND       0x10

    ASN1_OP_MATCH           = 0x00,
    ASN1_OP_MATCH_OR_SKIP       = 0x01,
    ASN1_OP_MATCH_ACT       = 0x02,
    ASN1_OP_MATCH_ACT_OR_SKIP   = 0x03,
    ASN1_OP_MATCH_JUMP      = 0x04,
    ASN1_OP_MATCH_JUMP_OR_SKIP  = 0x05,
    ASN1_OP_MATCH_ANY       = 0x08,
    ASN1_OP_MATCH_ANY_ACT       = 0x0a,
    /* Everything before here matches unconditionally */

    ASN1_OP_COND_MATCH_OR_SKIP  = 0x11,
    ASN1_OP_COND_MATCH_ACT_OR_SKIP  = 0x13,
    ASN1_OP_COND_MATCH_JUMP_OR_SKIP = 0x15,
    ASN1_OP_COND_MATCH_ANY      = 0x18,
    ASN1_OP_COND_MATCH_ANY_ACT  = 0x1a,

    /* Everything before here will want a tag from the data */
#define ASN1_OP__MATCHES_TAG ASN1_OP_COND_MATCH_ANY_ACT

    /* These are here to help fill up space */
    ASN1_OP_COND_FAIL       = 0x1b,
    ASN1_OP_COMPLETE        = 0x1c,
    ASN1_OP_ACT         = 0x1d,
    ASN1_OP_RETURN          = 0x1e,

    /* The following eight have bit 0 -> SET, 1 -> OF, 2 -> ACT */
    ASN1_OP_END_SEQ         = 0x20,
    ASN1_OP_END_SET         = 0x21,
    ASN1_OP_END_SEQ_OF      = 0x22,
    ASN1_OP_END_SET_OF      = 0x23,
    ASN1_OP_END_SEQ_ACT     = 0x24,
    ASN1_OP_END_SET_ACT     = 0x25,
    ASN1_OP_END_SEQ_OF_ACT      = 0x26,
    ASN1_OP_END_SET_OF_ACT      = 0x27,
#define ASN1_OP_END__SET          0x01
#define ASN1_OP_END__OF           0x02
#define ASN1_OP_END__ACT          0x04

    ASN1_OP__NR
};

#define _tag(CLASS, CP, TAG) ((ASN1_##CLASS << 6) | (ASN1_##CP << 5) | ASN1_##TAG)
#define _tagn(CLASS, CP, TAG) ((ASN1_##CLASS << 6) | (ASN1_##CP << 5) | TAG)
#define _jump_target(N) (N)
#define _action(N) (N)

#endif /* _LINUX_ASN1_BER_BYTECODE_H */