0.9.28 make check fail for MHEG5 sample

[brchiu]

On Lubuntu 64bit environment, executing 'make check' under directory of MHEG5 sample,
I got the following error information.

Recoding sample-InterchangedObject-1.xer into DER and back (1)...
sample-InterchangedObject-1.xer: Decode failed past byte 120: Input processing error
Makefile:506: recipe for target 'check-xer' failed
make: *** [check-xer] Error 2

Below is some GDB debug information, which shows the failure occurred when function OCTET_STRING__convert_hexadecimal trying to decode ExternalReference element.

(gdb) r -b 8192 -ixer -oder sample-InterchangedObject-1.xer
The program being debugged has been started already.
Start it from the beginning? (y or n) y
Starting program: /media/brchiu/Data/DocCollect/SoftwareTech/asn1c/asn1c-0.9.28/examples/sample.source.MHEG5/mheg5dump -b 8192 -ixer -oder sample-InterchangedObject-1.xer

Breakpoint 2, OCTET_STRING__convert_hexadecimal (sptr=0x668270, chunk_buf=0x6652b8,
chunk_size=4, have_more=1) at OCTET_STRING.c:784
784 OCTET_STRING_t st = (OCTET_STRING_t *)sptr;
(gdb) n
785 const char *chunk_stop = (const char *)chunk_buf;
(gdb) n
786 const char *p = chunk_stop;
(gdb) n
787 const char *pend = p + chunk_size;
(gdb) n
788 unsigned int clv = 0;
(gdb) n
789 int half = 0; / Half bit _/
(gdb) n
793 ssize_t _ns = st->size + (chunk_size + 1) / 2;
(gdb) n
794 void *nptr = REALLOC(st->buf, ns + 1);
(gdb) n
795 if(!nptr) return -1;
(gdb) n
796 st->buf = (uint8_t *)nptr;
(gdb) n
797 buf = st->buf + st->size;
(gdb) n
804 for(; p < pend; p++) {
(gdb) n
805 int ch = *(const unsigned char *)p;
(gdb) n
806 switch(ch) {
(gdb) n
824 *buf = 0; / JIC */
(gdb) n
825 return -1;
(gdb) p/x ch
$14 = 0x73
(gdb) bt

0 OCTET_STRING__convert_hexadecimal (sptr=0x668270, chunk_buf=0x6652b8, chunk_size=4,

have_more=1) at OCTET_STRING.c:825

1 0x000000000042d426 in xer_decode_general (opt_codec_ctx=0x7fffffffdc20, ctx=0x668280,

struct_key=0x668270, xml_tag=0x441c26 "group-identifier", buf_ptr=0x6652b8, size=4085, 
opt_unexpected_tag_decoder=0x0, 
body_receiver=0x425e18 <OCTET_STRING__convert_hexadecimal>) at xer_decoder.c:255

2 0x0000000000426aa8 in OCTET_STRING__decode_xer (opt_codec_ctx=0x7fffffffdc20,

td=0x664720 <asn_DEF_OCTET_STRING>, sptr=0x7fffffffd808, 
opt_mname=0x441c26 "group-identifier", buf_ptr=0x6652a6, size=4103, 
opt_unexpected_tag_decoder=0x0, 
body_receiver=0x425e18 <OCTET_STRING__convert_hexadecimal>) at OCTET_STRING.c:1148

3 0x0000000000426b2b in OCTET_STRING_decode_xer_hex (opt_codec_ctx=0x7fffffffdc20,

td=0x664720 <asn_DEF_OCTET_STRING>, sptr=0x7fffffffd808, 
opt_mname=0x441c26 "group-identifier", buf_ptr=0x6652a6, size=4103)
at OCTET_STRING.c:1166

4 0x0000000000419bbc in SEQUENCE_decode_xer (opt_codec_ctx=0x7fffffffdc20,

td=0x663a40 <asn_DEF_ExternalReference>, struct_ptr=0x7fffffffd918, 
opt_mname=0x441b24 "external-reference", buf_ptr=0x6652a6, size=4103)
at constr_SEQUENCE.c:677

5 0x00000000004160ce in CHOICE_decode_xer (opt_codec_ctx=0x7fffffffdc20,

td=0x650280 <asn_DEF_RootClass>, struct_ptr=0x7fffffffda20, 
opt_mname=0x4342e0 "rootClass", buf_ptr=0x665281, size=4140) at constr_CHOICE.c:616

6 0x000000000041f115 in SET_decode_xer (opt_codec_ctx=0x7fffffffdc20,

td=0x651e00 <asn_DEF_SceneClass>, struct_ptr=0x7fffffffdb28, opt_mname=0x433444 "scene", 
buf_ptr=0x665269, size=4164) at constr_SET.c:661

7 0x00000000004160ce in CHOICE_decode_xer (opt_codec_ctx=0x7fffffffdc20,

td=0x6501e0 <asn_DEF_InterchangedObject>, struct_ptr=0x7fffffffdc88, opt_mname=0x0, 
buf_ptr=0x665259, size=4180) at constr_CHOICE.c:616

8 0x000000000042cec6 in xer_decode (opt_codec_ctx=0x7fffffffdc20,

td=0x6501e0 <asn_DEF_InterchangedObject>, struct_ptr=0x7fffffffdc88, buffer=0x665240, 
size=4205) at xer_decoder.c:37

---Type to continue, or q to quit---

9 0x0000000000432b3c in data_decode_from_file (

pduType=0x6501e0 <asn_DEF_InterchangedObject>, file=0x665010, 
name=0x7fffffffe2f8 "sample-InterchangedObject-1.xer", suggested_bufsize=8192, 
on_first_pdu=1) at converter-sample.c:635

10 0x00000000004318a4 in main (ac=1, av=0x7fffffffdf30) at converter-sample.c:263

(gdb) p asn_DEF_ExternalReference
$15 = {name = 0x441cb0 "ExternalReference", xml_tag = 0x441cb0 "ExternalReference",
free_struct = 0x41ac6f <SEQUENCE_free>, print_struct = 0x41a9dd <SEQUENCE_print>,
check_constraints = 0x41ad8e <SEQUENCE_constraint>,
ber_decoder = 0x417f1c <SEQUENCE_decode_ber>,
der_encoder = 0x41946a <SEQUENCE_encode_der>,
xer_decoder = 0x4199ab <SEQUENCE_decode_xer>,
xer_encoder = 0x41a476 <SEQUENCE_encode_xer>, uper_decoder = 0x0, uper_encoder = 0x0,
outmost_tag = 0x0, tags = 0x441c48 <asn_DEF_ExternalReference_tags_1>, tags_count = 1,
all_tags = 0x441c48 <asn_DEF_ExternalReference_tags_1>, all_tags_count = 1,
per_constraints = 0x0, elements = 0x6639c0 <asn_MBR_ExternalReference_1>,
elements_count = 2, specifics = 0x441c80 <asn_SPC_ExternalReference_specs_1>}

[brchiu]

In 2017-03-26 release, make check still failed with the following message :

Recoding sample-InterchangedObject-1.xer into DER and back (1)...
sample-InterchangedObject-1.xer: Decode failed past byte 120: Input processing error
Makefile:506: recipe for target 'check-xer' failed
make: *** [check-xer] Error 2

[brchiu]

After check stack trace, this failure occurs when reading character 's' of 'smth' of the <group-identifier>...</group-identifier> tag because OCTET_STRING__convert_hexadecimal verdict 's' is not an valid hex-decimal character. However, since OCTET_STRING.c has OCTET_STRING_decode_xer_hex as its xer_decoder field of asn_DEF_OCTET_STRING. This 'failed' verdict is inevitable unless we change it to other XER decoding function for OCTECT_STRING.

Perhaps someone who is more familiar with X.693 can advice how to solve it.

Excerpt of sample-InterchangedObject-1.xer :

<InterchangedObject>
    <scene>
        <rootClass>
            <external-reference>
                <group-identifier>smth</group-identifier>  <-- failed when reading 's' of 'smth'
                <object-number>0</object-number>
            </external-reference>
        </rootClass>

</InterchangedObject>

[velichkov]

Hi @brchiu,

The oss tool also fails to decode sample-InterchangedObject-1.xer with similar error about group-identifier so I guess the sample-InterchangedObject-1.xer was generated with older version and is not correct.