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add OER SEQUENCE decoder

This commit is contained in:
Lev Walkin 2017-07-20 11:21:30 +03:00
parent 98eabc1c82
commit d88bea9b11
7 changed files with 428 additions and 10 deletions
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1
skeletons/Makefile.am
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@ -63,6 +63,7 @@ libasn1cskeletons_la_SOURCES = \
ber_tlv_tag.c ber_tlv_tag.h \
constr_CHOICE.c constr_CHOICE.h \
constr_SEQUENCE.c constr_SEQUENCE.h \
constr_SEQUENCE_oer.c constr_SEQUENCE_oer.h \
constr_SEQUENCE_OF.c constr_SEQUENCE_OF.h \
constr_SET.c constr_SET.h \
constr_SET_OF.c constr_SET_OF.h \

1
skeletons/constr_SEQUENCE.h
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@ -6,6 +6,7 @@
#define _CONSTR_SEQUENCE_H_
#include <asn_application.h>
#include <constr_SEQUENCE_oer.h>
#ifdef __cplusplus
extern "C" {

374
skeletons/constr_SEQUENCE_oer.c Normal file
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@ -0,0 +1,374 @@
/*
* Copyright (c) 2017 Lev Walkin <vlm@lionet.info>.
* All rights reserved.
* Redistribution and modifications are permitted subject to BSD license.
*/
#ifndef ASN_DISABLE_OER_SUPPORT
#include <asn_internal.h>
#include <constr_SEQUENCE.h>
#include <errno.h>
/*
* This macro "eats" the part of the buffer which is definitely "consumed",
* i.e. was correctly converted into local representation or rightfully skipped.
*/
#undef ADVANCE
#define ADVANCE(num_bytes) \
do { \
size_t num = num_bytes; \
ptr = ((const char *)ptr) + num; \
size -= num; \
consumed_myself += num; \
} while(0)
/*
* Switch to the next phase of parsing.
*/
#undef NEXT_PHASE
#undef PHASE_OUT
#define NEXT_PHASE(ctx) \
do { \
ctx->phase++; \
ctx->step = 0; \
} while(0)
/*
* Check whether we are inside the extensions group.
*/
#define IN_EXTENSION_GROUP(specs, memb_idx) \
( ((memb_idx) > (specs)->ext_after) \
&&((memb_idx) < (specs)->ext_before))
/*
* Return a standardized complex structure.
*/
#undef RETURN
#define RETURN(_code) do { \
rval.code = _code; \
rval.consumed = consumed_myself;\
return rval; \
} while(0)
asn_dec_rval_t
SEQUENCE_decode_oer(asn_codec_ctx_t *opt_codec_ctx, asn_TYPE_descriptor_t *td,
asn_oer_constraints_t *constraints, void **struct_ptr,
const void *ptr, size_t size) {
asn_SEQUENCE_specifics_t *specs = (asn_SEQUENCE_specifics_t *)td->specifics;
asn_dec_rval_t rval = {RC_OK, 0};
void *st = *struct_ptr; /* Target structure */
asn_struct_ctx_t *ctx; /* Decoder context */
size_t consumed_myself = 0; /* Consumed bytes from ptr. */
(void)opt_codec_ctx;
(void)specs;
/*
* Create the target structure if it is not present already.
*/
if(st == 0) {
st = *struct_ptr = CALLOC(1, specs->struct_size);
if(st == 0) {
RETURN(RC_FAIL);
}
}
/*
* Restore parsing context.
*/
ctx = (asn_struct_ctx_t *)((char *)st + specs->ctx_offset);
if(ctx->ptr == 0) {
ctx->ptr = CALLOC(1, sizeof(asn_per_data_t));
if(!ctx->ptr) {
RETURN(RC_FAIL);
}
}
/*
* Start to parse where left previously.
*/
switch(ctx->phase) {
case 0: {
/*
* Fetch preamble.
*/
asn_per_data_t *preamble = ctx->ptr;
int has_extensions = (specs->ext_before >= 0);
size_t preamble_bits = (has_extensions + specs->roms_count);
size_t preamble_bytes = (preamble_bits >> 3);
uint8_t *pbytes;
if(size < preamble_bytes) {
ASN__DECODE_STARVED;
}
pbytes = MALLOC(preamble_bytes + 1);
if(!pbytes) {
RETURN(RC_FAIL);
}
preamble->buffer = (const void *)pbytes;
memcpy(pbytes, ptr, preamble_bytes);
pbytes[preamble_bytes] = '\0'; /* Just in case */
preamble->nboff = has_extensions;
preamble->nbits = preamble_bits;
ADVANCE(preamble_bytes);
}
NEXT_PHASE(ctx);
/* FALL THROUGH */
case 1: {
/* Decode components of the extension root */
asn_per_data_t *preamble = ctx->ptr;
size_t edx;
for(edx = (ctx->step >> 1); edx < td->elements_count;
edx++, ctx->step = (ctx->step & ~1) + 2) {
asn_TYPE_member_t *elm = &td->elements[edx];
void **memb_ptr2; /* Pointer to a pointer to a memmber */
if(ctx->step & 1) {
goto microphase2_decode_continues;
}
if(IN_EXTENSION_GROUP(specs, edx)) {
/* Ignore non-root components in PHASE 1 */
continue;
}
if(elm->optional) {
int32_t present = per_get_few_bits(preamble, 1);
if(present < 0) {
RETURN(RC_FAIL);
} else if(present == 0) {
if(elm->default_value) {
if(elm->flags & ATF_POINTER) {
/* Member is a pointer to another structure */
memb_ptr2 =
(void **)((char *)st + elm->memb_offset);
} else {
void *memb_ptr = (char *)st + elm->memb_offset;
memb_ptr2 = &memb_ptr;
}
/* Fill-in DEFAULT */
if(elm->default_value(1, memb_ptr2)) {
RETURN(RC_FAIL);
}
}
/* The member is not present. */
continue;
}
/* Present OPTIONAL or DEFAULT component. */
}
/*
* MICROPHASE 2: Invoke the member-specific decoder.
*/
ctx->step |= 1; /* Confirm entering next microphase */
microphase2_decode_continues:
if(elm->flags & ATF_POINTER) {
/* Member is a pointer to another structure */
memb_ptr2 = (void **)((char *)st + elm->memb_offset);
} else {
void *memb_ptr = (char *)st + elm->memb_offset;
memb_ptr2 = &memb_ptr;
}
rval = elm->type->oer_decoder(opt_codec_ctx, elm->type,
elm->oer_constraints, memb_ptr2, ptr,
size);
switch(rval.code) {
case RC_OK:
ADVANCE(rval.consumed);
break;
case RC_WMORE:
ADVANCE(rval.consumed);
RETURN(RC_WMORE);
case RC_FAIL:
RETURN(RC_FAIL);
}
} /* for(all root members) */
}
NEXT_PHASE(ctx);
/* FALL THROUGH */
case 2: {
/* Cleanup preamble. */
asn_per_data_t *preamble = ctx->ptr;
asn_per_data_t *extadds;
int has_extensions = (specs->ext_before >= 0);
int extensions_present =
has_extensions && (((const uint8_t *)preamble->buffer)[0] & 0x80);
uint8_t unused_bits;
size_t len = 0;
ssize_t len_len;
uint8_t *ebytes;
union {
const uint8_t *cptr;
uint8_t *uptr;
} unconst;
unconst.cptr = preamble->buffer;
FREEMEM(unconst.uptr);
preamble->buffer = 0;
if(!extensions_present) {
ctx->phase = 10;
RETURN(RC_OK);
}
/*
* X.696 (08/2015) #16.1 (c), #16.4
* Read in the extension addition presence bitmap.
*/
len_len = oer_fetch_length(ptr, size, &len);
if(len_len > 0) {
ADVANCE(len_len);
} if(len_len < 0) {
RETURN(RC_FAIL);
} else {
RETURN(RC_WMORE);
}
if(len == 0) {
/* 16.4.1-2 */
RETURN(RC_FAIL);
} else if(len > size) {
RETURN(RC_WMORE);
}
/* Account for unused bits */
unused_bits = 0x7 & *(const uint8_t *)ptr;
ADVANCE(1);
len--;
if(unused_bits && len == 0) {
RETURN(RC_FAIL);
}
/* Get the extensions map */
ebytes = MALLOC(len + 1);
if(!ebytes) {
RETURN(RC_FAIL);
}
memcpy(ebytes, ptr, len);
ebytes[len] = '\0';
extadds = preamble;
memset(extadds, 0, sizeof(*extadds));
extadds->buffer = ebytes;
extadds->nboff = 0;
extadds->nbits = 8 * len - unused_bits;
ADVANCE(len);
}
NEXT_PHASE(ctx);
ctx->step = (specs->ext_after + 1);
/* Fall through */
case 3:
for(; ctx->step < specs->ext_before; ctx->step++) {
asn_per_data_t *extadds = ctx->ptr;
size_t edx = ctx->step;
asn_TYPE_member_t *elm = &td->elements[edx];
void **memb_ptr2;
if(elm->flags & ATF_POINTER) {
/* Member is a pointer to another structure */
memb_ptr2 = (void **)((char *)st + elm->memb_offset);
} else {
void *memb_ptr = (char *)st + elm->memb_offset;
memb_ptr2 = &memb_ptr;
assert(elm->flags & ATF_POINTER); /* Extensions are indirect */
}
switch(per_get_few_bits(extadds, 1)) {
case -1:
/*
* Not every one of our extensions is known to the remote side.
* Continue filling in their defaults though.
*/
/* Fall through */
case 0:
/* Fill-in DEFAULT */
if(elm->default_value && elm->default_value(1, memb_ptr2)) {
RETURN(RC_FAIL);
}
continue;
case 1: {
/* Read OER open type */
ssize_t ot_size = oer_open_type_get(opt_codec_ctx, elm->type,
elm->oer_constraints,
memb_ptr2, ptr, size);
if(ot_size > 0) {
ADVANCE(ot_size);
} else if(ot_size < 0) {
RETURN(RC_FAIL);
} else {
/* Roll back open type parsing */
per_get_undo(extadds, 1);
ASN_STRUCT_FREE(*elm->type, *memb_ptr2);
*memb_ptr2 = NULL;
RETURN(RC_WMORE);
}
break;
}
default:
RETURN(RC_FAIL);
}
}
NEXT_PHASE(ctx);
/* Fall through */
case 4:
/* Read in the rest of Open Types while ignoring them */
for(;;) {
asn_per_data_t *extadds = ctx->ptr;
switch(per_get_few_bits(extadds, 1)) {
case 0:
continue;
case 1: {
ssize_t slurped = oer_open_type_slurp(ptr, size);
if(slurped > 0) {
ADVANCE(slurped);
} else if(slurped < 0) {
RETURN(RC_FAIL);
} else {
per_get_undo(extadds, 1);
RETURN(RC_WMORE);
}
continue;
}
case -1:
/* No more Open Type encoded components */
break;
default:
RETURN(RC_FAIL);
}
break;
}
}
return rval;
}
/*
* Encode as Canonical OER.
*/
asn_enc_rval_t
SEQUENCE_encode_oer(asn_TYPE_descriptor_t *td,
asn_oer_constraints_t *constraints, void *sptr,
asn_app_consume_bytes_f *cb, void *app_key) {
asn_enc_rval_t er;
const uint8_t *buf;
const uint8_t *end;
size_t useful_bytes;
size_t req_bytes = 0;
int encode_as_unsigned;
int sign = 0;
er.encoded = -1;
return er;
}
#endif /* ASN_DISABLE_OER_SUPPORT */

20
skeletons/constr_SEQUENCE_oer.h Normal file
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@ -0,0 +1,20 @@
/*-
* Copyright (c) 2017 Lev Walkin <vlm@lionet.info>. All rights reserved.
* Redistribution and modifications are permitted subject to BSD license.
*/
#ifndef CONSTR_SEQUENCE_OER_H
#define CONSTR_SEQUENCE_OER_H
#ifdef __cplusplus
extern "C" {
#endif
#include <asn_application.h>
#include <asn_codecs.h>
oer_type_decoder_f SEQUENCE_decode_oer;
oer_type_encoder_f SEQUENCE_encode_oer;
#ifdef __cplusplus
}
#endif
#endif /* CONSTR_SEQUENCE_OER_H */

28
skeletons/oer_decoder.h
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@ -2,8 +2,8 @@
* Copyright (c) 2017 Lev Walkin <vlm@lionet.info>. All rights reserved.
* Redistribution and modifications are permitted subject to BSD license.
*/
#ifndef _OER_DECODER_H_
#define _OER_DECODER_H_
#ifndef OER_DECODER_H
#define OER_DECODER_H
#include <asn_application.h>
#include <oer_support.h>
@ -37,8 +37,30 @@ typedef asn_dec_rval_t(oer_type_decoder_f)(
const void *buf_ptr,
size_t size);
/*
* Swallow the Open Type (X.696 (08/2015), #30) into /dev/null.
* RETURN VALUES:
* 0: More data expected than bufptr contains.
* -1: Fatal error deciphering length.
* >0: Number of bytes used from bufptr.
*/
ssize_t oer_open_type_slurp(const void *bufptr, size_t size);
/*
* Read the Open Type (X.696 (08/2015), #30).
* RETURN VALUES:
* 0: More data expected than bufptr contains.
* -1: Fatal error deciphering length.
* >0: Number of bytes used from bufptr.
*/
ssize_t oer_open_type_get(asn_codec_ctx_t *opt_codec_ctx,
struct asn_TYPE_descriptor_s *td,
asn_oer_constraints_t *constraints, void **struct_ptr,
const void *bufptr, size_t size);
#ifdef __cplusplus
}
#endif
#endif /* _OER_DECODER_H_ */
#endif /* OER_DECODER_H */

6
skeletons/oer_encoder.h
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@ -2,8 +2,8 @@
* Copyright (c) 2017 Lev Walkin <vlm@lionet.info>. All rights reserved.
* Redistribution and modifications are permitted subject to BSD license.
*/
#ifndef _OER_ENCODER_H_
#define _OER_ENCODER_H_
#ifndef OER_ENCODER_H
#define OER_ENCODER_H
#include <asn_application.h>
@ -48,4 +48,4 @@ typedef asn_enc_rval_t(oer_type_encoder_f)(
}
#endif
#endif /* _OER_ENCODER_H_ */
#endif /* OER_ENCODER_H */

8
skeletons/oer_support.h
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@ -3,8 +3,8 @@
* All rights reserved.
* Redistribution and modifications are oermitted subject to BSD license.
*/
#ifndef _OER_SUPPORT_H_
#define _OER_SUPPORT_H_
#ifndef OER_SUPPORT_H
#define OER_SUPPORT_H
#include <asn_system.h> /* Platform-specific types */
@ -30,7 +30,7 @@ typedef const struct asn_oer_constraints_s {
/*
* Fetch the length determinant (X.696 08/2015, #8.6) into *len_r.
* Fetch the length determinant (X.696 (08/2015), #8.6) into *len_r.
* RETURN VALUES:
* 0: More data expected than bufptr contains.
* -1: Fatal error deciphering length.
@ -49,4 +49,4 @@ ssize_t oer_serialize_length(size_t length, asn_app_consume_bytes_f *cb, void *a
}
#endif
#endif /* _OER_SUPPORT_H_ */
#endif /* OER_SUPPORT_H */