… | |
… | |
4 | |
4 | |
5 | =head1 SYNOPSIS |
5 | =head1 SYNOPSIS |
6 | |
6 | |
7 | use Convert::BER::XS ':all'; |
7 | use Convert::BER::XS ':all'; |
8 | |
8 | |
|
|
9 | # decode a binary BER data structure using the SNMP profile |
9 | my $ber = ber_decode $buf, $Convert::BER::XS::SNMP_PROFILE |
10 | my $ber = ber_decode $buf, $Convert::BER::XS::SNMP_PROFILE |
10 | or die "unable to decode SNMP message"; |
11 | or die "unable to decode SNMP message"; |
11 | |
12 | |
12 | # The above results in a data structure consisting of |
13 | # The above results in a data structure consisting of |
13 | # (class, tag, flags, data) |
14 | # (class, tag, flags, data) |
14 | # tuples. Below is such a message, SNMPv1 trap |
15 | # tuples. Below is such a message, an SNMPv1 trap |
15 | # with a Cisco mac change notification. |
16 | # with a Cisco mac change notification. |
16 | # Did you know that Cisco is in the news almost |
17 | # (Did you know that Cisco is in the news almost |
17 | # every week because of some backdoor password |
18 | # every week because of some backdoor password |
18 | # or other extremely stupid security bug? |
19 | # or other extremely stupid security bug?) |
19 | |
20 | |
20 | [ ASN_UNIVERSAL, ASN_SEQUENCE, 1, |
21 | [ ASN_UNIVERSAL, ASN_SEQUENCE, 1, |
21 | [ |
22 | [ |
22 | [ ASN_UNIVERSAL, ASN_INTEGER, 0, 0 ], # snmp version 1 |
23 | [ ASN_UNIVERSAL, ASN_INTEGER, 0, 0 ], # snmp version 1 |
23 | [ ASN_UNIVERSAL, 4, 0, "public" ], # community |
24 | [ ASN_UNIVERSAL, 4, 0, "public" ], # community |
… | |
… | |
37 | ] |
38 | ] |
38 | ] |
39 | ] |
39 | ], |
40 | ], |
40 | ... |
41 | ... |
41 | |
42 | |
|
|
43 | # let's dump the above structure, for debugging |
|
|
44 | ber_dump $ber, $Convert::BER::XS::SNMP_PROFILE; |
|
|
45 | |
42 | # let's decode it a bit with some helper functions |
46 | # let's decode it a bit with some helper functions. |
43 | |
47 | # first check whether it starts with a sequence |
44 | my $msg = ber_is_seq $ber |
48 | my $msg = ber_is_seq $ber |
45 | or die "SNMP message does not start with a sequence"; |
49 | or die "SNMP message does not start with a sequence"; |
46 | |
50 | |
|
|
51 | # then check if its some kind of integer |
47 | ber_is $msg->[0], ASN_UNIVERSAL, ASN_INTEGER, 0 |
52 | ber_is $msg->[0], ASN_UNIVERSAL, ASN_INTEGER, 0 |
48 | or die "SNMP message does not start with snmp version\n"; |
53 | or die "SNMP message does not start with snmp version"; |
49 | |
54 | |
50 | # message is SNMP v1 or v2c? |
55 | # message is SNMP v1 or v2c? |
51 | if ($msg->[0][BER_DATA] == 0 || $msg->[0][BER_DATA] == 1) { |
56 | if ($msg->[0][BER_DATA] == 0 || $msg->[0][BER_DATA] == 1) { |
52 | |
57 | |
53 | # message is v1 trap? |
58 | # message is v1 trap? |
… | |
… | |
61 | and (ber_is_int $trap->[3], 1) # mac changed msg |
66 | and (ber_is_int $trap->[3], 1) # mac changed msg |
62 | ) { |
67 | ) { |
63 | ... and so on |
68 | ... and so on |
64 | |
69 | |
65 | # finally, let's encode it again and hope it results in the same bit pattern |
70 | # finally, let's encode it again and hope it results in the same bit pattern |
66 | |
|
|
67 | my $buf = ber_encode $ber, $Convert::BER::XS::SNMP_PROFILE; |
71 | my $buf = ber_encode $ber, $Convert::BER::XS::SNMP_PROFILE; |
68 | |
72 | |
69 | =head1 DESCRIPTION |
73 | =head1 DESCRIPTION |
70 | |
|
|
71 | WARNING: Before release 1.0, the API is not considered stable in any way. |
|
|
72 | |
74 | |
73 | This module implements a I<very> low level BER/DER en-/decoder. |
75 | This module implements a I<very> low level BER/DER en-/decoder. |
74 | |
76 | |
75 | It is tuned for low memory and high speed, while still maintaining some |
77 | It is tuned for low memory and high speed, while still maintaining some |
76 | level of user-friendlyness. |
78 | level of user-friendlyness. |
… | |
… | |
105 | BER_CLASS BER_TAG BER_FLAGS BER_DATA |
107 | BER_CLASS BER_TAG BER_FLAGS BER_DATA |
106 | |
108 | |
107 | =item C<:const_asn> |
109 | =item C<:const_asn> |
108 | |
110 | |
109 | ASN class values (these are C<0>, C<1>, C<2> and C<3>, respectively - |
111 | ASN class values (these are C<0>, C<1>, C<2> and C<3>, respectively - |
110 | exactly thw two topmost bits from the identifier octet shifted 6 bits to |
112 | exactly the two topmost bits from the identifier octet shifted 6 bits to |
111 | the right): |
113 | the right): |
112 | |
114 | |
113 | ASN_UNIVERSAL ASN_APPLICATION ASN_CONTEXT ASN_PRIVATE |
115 | ASN_UNIVERSAL ASN_APPLICATION ASN_CONTEXT ASN_PRIVATE |
114 | |
116 | |
115 | ASN tag values (some of which are aliases, such as C<ASN_OID>). Their |
117 | ASN tag values (some of which are aliases, such as C<ASN_OID>). Their |
116 | numerical value corresponds exactly to the numbers used in BER/X.690. |
118 | numerical value corresponds exactly to the numbers used in BER/X.690. |
117 | |
119 | |
118 | ASN_BOOLEAN ASN_INTEGER ASN_BIT_STRING ASN_OCTET_STRING ASN_NULL ASN_OBJECT_IDENTIFIER |
120 | ASN_BOOLEAN ASN_INTEGER ASN_BIT_STRING ASN_OCTET_STRING ASN_NULL ASN_OID |
119 | ASN_OBJECT_DESCRIPTOR ASN_OID ASN_EXTERNAL ASN_REAL ASN_SEQUENCE ASN_ENUMERATED |
121 | ASN_OBJECT_IDENTIFIER ASN_OBJECT_DESCRIPTOR ASN_EXTERNAL ASN_REAL ASN_SEQUENCE ASN_ENUMERATED |
120 | ASN_EMBEDDED_PDV ASN_UTF8_STRING ASN_RELATIVE_OID ASN_SET ASN_NUMERIC_STRING |
122 | ASN_EMBEDDED_PDV ASN_UTF8_STRING ASN_RELATIVE_OID ASN_SET ASN_NUMERIC_STRING |
121 | ASN_PRINTABLE_STRING ASN_TELETEX_STRING ASN_T61_STRING ASN_VIDEOTEX_STRING ASN_IA5_STRING |
123 | ASN_PRINTABLE_STRING ASN_TELETEX_STRING ASN_T61_STRING ASN_VIDEOTEX_STRING ASN_IA5_STRING |
122 | ASN_ASCII_STRING ASN_UTC_TIME ASN_GENERALIZED_TIME ASN_GRAPHIC_STRING ASN_VISIBLE_STRING |
124 | ASN_ASCII_STRING ASN_UTC_TIME ASN_GENERALIZED_TIME ASN_GRAPHIC_STRING ASN_VISIBLE_STRING |
123 | ASN_ISO646_STRING ASN_GENERAL_STRING ASN_UNIVERSAL_STRING ASN_CHARACTER_STRING ASN_BMP_STRING |
125 | ASN_ISO646_STRING ASN_GENERAL_STRING ASN_UNIVERSAL_STRING ASN_CHARACTER_STRING ASN_BMP_STRING |
124 | |
126 | |
… | |
… | |
141 | |
143 | |
142 | =item C<:decode> |
144 | =item C<:decode> |
143 | |
145 | |
144 | C<ber_decode> and the match helper functions: |
146 | C<ber_decode> and the match helper functions: |
145 | |
147 | |
|
|
148 | ber_decode ber-decode_prefix |
146 | ber_decode ber_is ber_is_seq ber_is_int ber_is_oid |
149 | ber_is ber_is_seq ber_is_int ber_is_oid |
|
|
150 | ber_dump |
147 | |
151 | |
148 | =item C<:encode> |
152 | =item C<:encode> |
149 | |
153 | |
150 | C<ber_encode> and the construction helper functions: |
154 | C<ber_encode> and the construction helper functions: |
151 | |
155 | |
152 | ber_encode ber_int |
156 | ber_encode |
|
|
157 | ber_int |
153 | |
158 | |
154 | =back |
159 | =back |
155 | |
160 | |
156 | =head2 ASN.1/BER/DER/... BASICS |
161 | =head2 ASN.1/BER/DER/... BASICS |
157 | |
162 | |
… | |
… | |
169 | This works because BER values are tagged with a type and a namespace, |
174 | This works because BER values are tagged with a type and a namespace, |
170 | and also have a flag that says whether a value consists of subvalues (is |
175 | and also have a flag that says whether a value consists of subvalues (is |
171 | "constructed") or not (is "primitive"). |
176 | "constructed") or not (is "primitive"). |
172 | |
177 | |
173 | Tags are simple integers, and ASN.1 defines a somewhat weird assortment |
178 | Tags are simple integers, and ASN.1 defines a somewhat weird assortment |
174 | of those - for example, you have one integers and 16(!) different |
179 | of those - for example, you have one integer but 16(!) different |
175 | string types, but there is no Unsigned32 type for example. Different |
180 | string types, but there is no Unsigned32 type for example. Different |
176 | applications work around this in different ways, for example, SNMP defines |
181 | applications work around this in different ways, for example, SNMP defines |
177 | application-specific Gauge32, Counter32 and Unsigned32, which are mapped |
182 | application-specific Gauge32, Counter32 and Unsigned32, which are mapped |
178 | to two different tags: you can distinguish between Counter32 and the |
183 | to two different tags: you can distinguish between Counter32 and the |
179 | others, but not between Gause32 and Unsigned32, without the ASN.1 schema. |
184 | others, but not between Gause32 and Unsigned32, without the ASN.1 schema. |
… | |
… | |
253 | |
258 | |
254 | =head2 DECODING AND ENCODING |
259 | =head2 DECODING AND ENCODING |
255 | |
260 | |
256 | =over |
261 | =over |
257 | |
262 | |
258 | =item $tuple = ber_decoded $bindata[, $profile] |
263 | =item $tuple = ber_decode $bindata[, $profile] |
259 | |
264 | |
260 | Decodes binary BER data in C<$bindata> and returns the resulting BER |
265 | Decodes binary BER data in C<$bindata> and returns the resulting BER |
261 | tuple. Croaks on any decoding error, so the returned C<$tuple> is always |
266 | tuple. Croaks on any decoding error, so the returned C<$tuple> is always |
262 | valid. |
267 | valid. |
263 | |
268 | |
… | |
… | |
276 | |
281 | |
277 | Example: as above, but use the provided SNMP profile. |
282 | Example: as above, but use the provided SNMP profile. |
278 | |
283 | |
279 | $tuple = ber_encode $data, $Convert::BER::XS::SNMP_PROFILE; |
284 | $tuple = ber_encode $data, $Convert::BER::XS::SNMP_PROFILE; |
280 | |
285 | |
|
|
286 | =item ($tuple, $bytes) = ber_decode_prefix $bindata[, $profile] |
|
|
287 | |
|
|
288 | Works like C<ber_decode>, except it doesn't croak when there is data after |
|
|
289 | the BER data, but instead returns the decoded value and the number of |
|
|
290 | bytes it decoded. |
|
|
291 | |
|
|
292 | This is useful when you have BER data at the start of a buffer and other |
|
|
293 | data after, and you need to find the length. |
|
|
294 | |
|
|
295 | Also, since BER is self-delimited, this can be used to decode multiple BER |
|
|
296 | values joined together. |
|
|
297 | |
281 | =item $bindata = ber_encode $tuple[, $profile] |
298 | =item $bindata = ber_encode $tuple[, $profile] |
282 | |
299 | |
283 | Encodes the BER tuple into a BER/DER data structure. AS with |
300 | Encodes the BER tuple into a BER/DER data structure. As with |
284 | Cyber_decode>, an optional profile can be given. |
301 | Cyber_decode>, an optional profile can be given. |
285 | |
302 | |
286 | The encoded data should be both BER and DER ("shortest form") compliant |
303 | The encoded data should be both BER and DER ("shortest form") compliant |
287 | unless the input says otherwise (e.g. it uses constructed strings). |
304 | unless the input says otherwise (e.g. it uses constructed strings). |
288 | |
305 | |
… | |
… | |
391 | use common::sense; |
408 | use common::sense; |
392 | |
409 | |
393 | use XSLoader (); |
410 | use XSLoader (); |
394 | use Exporter qw(import); |
411 | use Exporter qw(import); |
395 | |
412 | |
|
|
413 | use Carp (); |
|
|
414 | |
396 | our $VERSION; |
415 | our $VERSION; |
397 | |
416 | |
398 | BEGIN { |
417 | BEGIN { |
399 | $VERSION = 0.9; |
418 | $VERSION = 1.21; |
400 | XSLoader::load __PACKAGE__, $VERSION; |
419 | XSLoader::load __PACKAGE__, $VERSION; |
401 | } |
420 | } |
402 | |
421 | |
403 | our %EXPORT_TAGS = ( |
422 | our %EXPORT_TAGS = ( |
404 | const_index => [qw( |
423 | const_index => [qw( |
405 | BER_CLASS BER_TAG BER_FLAGS BER_DATA |
424 | BER_CLASS BER_TAG BER_FLAGS BER_DATA |
406 | )], |
425 | )], |
|
|
426 | const_asn_class => [qw( |
|
|
427 | ASN_UNIVERSAL ASN_APPLICATION ASN_CONTEXT ASN_PRIVATE |
|
|
428 | )], |
407 | const_asn => [qw( |
429 | const_asn_tag => [qw( |
408 | ASN_BOOLEAN ASN_INTEGER ASN_BIT_STRING ASN_OCTET_STRING ASN_NULL ASN_OBJECT_IDENTIFIER |
430 | ASN_BOOLEAN ASN_INTEGER ASN_BIT_STRING ASN_OCTET_STRING ASN_NULL ASN_OID ASN_OBJECT_IDENTIFIER |
409 | ASN_OBJECT_DESCRIPTOR ASN_OID ASN_EXTERNAL ASN_REAL ASN_SEQUENCE ASN_ENUMERATED |
431 | ASN_OBJECT_DESCRIPTOR ASN_EXTERNAL ASN_REAL ASN_SEQUENCE ASN_ENUMERATED |
410 | ASN_EMBEDDED_PDV ASN_UTF8_STRING ASN_RELATIVE_OID ASN_SET ASN_NUMERIC_STRING |
432 | ASN_EMBEDDED_PDV ASN_UTF8_STRING ASN_RELATIVE_OID ASN_SET ASN_NUMERIC_STRING |
411 | ASN_PRINTABLE_STRING ASN_TELETEX_STRING ASN_T61_STRING ASN_VIDEOTEX_STRING ASN_IA5_STRING |
433 | ASN_PRINTABLE_STRING ASN_TELETEX_STRING ASN_T61_STRING ASN_VIDEOTEX_STRING ASN_IA5_STRING |
412 | ASN_ASCII_STRING ASN_UTC_TIME ASN_GENERALIZED_TIME ASN_GRAPHIC_STRING ASN_VISIBLE_STRING |
434 | ASN_ASCII_STRING ASN_UTC_TIME ASN_GENERALIZED_TIME ASN_GRAPHIC_STRING ASN_VISIBLE_STRING |
413 | ASN_ISO646_STRING ASN_GENERAL_STRING ASN_UNIVERSAL_STRING ASN_CHARACTER_STRING ASN_BMP_STRING |
435 | ASN_ISO646_STRING ASN_GENERAL_STRING ASN_UNIVERSAL_STRING ASN_CHARACTER_STRING ASN_BMP_STRING |
414 | |
|
|
415 | ASN_UNIVERSAL ASN_APPLICATION ASN_CONTEXT ASN_PRIVATE |
|
|
416 | )], |
436 | )], |
417 | const_ber_type => [qw( |
437 | const_ber_type => [qw( |
418 | BER_TYPE_BYTES BER_TYPE_UTF8 BER_TYPE_UCS2 BER_TYPE_UCS4 BER_TYPE_INT |
438 | BER_TYPE_BYTES BER_TYPE_UTF8 BER_TYPE_UCS2 BER_TYPE_UCS4 BER_TYPE_INT |
419 | BER_TYPE_OID BER_TYPE_RELOID BER_TYPE_NULL BER_TYPE_BOOL BER_TYPE_REAL |
439 | BER_TYPE_OID BER_TYPE_RELOID BER_TYPE_NULL BER_TYPE_BOOL BER_TYPE_REAL |
420 | BER_TYPE_IPADDRESS BER_TYPE_CROAK |
440 | BER_TYPE_IPADDRESS BER_TYPE_CROAK |
… | |
… | |
422 | const_snmp => [qw( |
442 | const_snmp => [qw( |
423 | SNMP_IPADDRESS SNMP_COUNTER32 SNMP_GAUGE32 SNMP_UNSIGNED32 |
443 | SNMP_IPADDRESS SNMP_COUNTER32 SNMP_GAUGE32 SNMP_UNSIGNED32 |
424 | SNMP_TIMETICKS SNMP_OPAQUE SNMP_COUNTER64 |
444 | SNMP_TIMETICKS SNMP_OPAQUE SNMP_COUNTER64 |
425 | )], |
445 | )], |
426 | decode => [qw( |
446 | decode => [qw( |
427 | ber_decode |
447 | ber_decode ber_decode_prefix |
428 | ber_is ber_is_seq ber_is_int ber_is_oid |
448 | ber_is ber_is_seq ber_is_int ber_is_oid |
|
|
449 | ber_dump |
429 | )], |
450 | )], |
430 | encode => [qw( |
451 | encode => [qw( |
431 | ber_encode |
452 | ber_encode |
432 | ber_int |
453 | ber_int |
433 | )], |
454 | )], |
434 | ); |
455 | ); |
435 | |
456 | |
436 | our @EXPORT_OK = map @$_, values %EXPORT_TAGS; |
457 | our @EXPORT_OK = map @$_, values %EXPORT_TAGS; |
437 | |
458 | |
438 | $EXPORT_TAGS{all} = \@EXPORT_OK; |
459 | $EXPORT_TAGS{all} = \@EXPORT_OK; |
|
|
460 | $EXPORT_TAGS{const_asn} = [map @{ $EXPORT_TAGS{$_} }, qw(const_asn_class const_asn_tag)]; |
439 | $EXPORT_TAGS{const} = [map @{ $EXPORT_TAGS{$_} }, qw(const_index const_asn)]; |
461 | $EXPORT_TAGS{const} = [map @{ $EXPORT_TAGS{$_} }, qw(const_index const_asn)]; |
|
|
462 | |
|
|
463 | our $DEFAULT_PROFILE = new Convert::BER::XS::Profile; |
|
|
464 | |
|
|
465 | $DEFAULT_PROFILE->_set_default; |
|
|
466 | |
|
|
467 | # additional SNMP application types |
|
|
468 | our $SNMP_PROFILE = new Convert::BER::XS::Profile; |
|
|
469 | |
|
|
470 | $SNMP_PROFILE->set (ASN_APPLICATION, SNMP_IPADDRESS , BER_TYPE_IPADDRESS); |
|
|
471 | $SNMP_PROFILE->set (ASN_APPLICATION, SNMP_COUNTER32 , BER_TYPE_INT); |
|
|
472 | $SNMP_PROFILE->set (ASN_APPLICATION, SNMP_COUNTER64 , BER_TYPE_INT); |
|
|
473 | $SNMP_PROFILE->set (ASN_APPLICATION, SNMP_UNSIGNED32, BER_TYPE_INT); |
|
|
474 | $SNMP_PROFILE->set (ASN_APPLICATION, SNMP_TIMETICKS , BER_TYPE_INT); |
|
|
475 | |
|
|
476 | # decodes REAL values according to ECMA-63 |
|
|
477 | # this is pretty strict, except it doesn't catch -0. |
|
|
478 | # I don't have access to ISO 6093 (or BS 6727, or ANSI X.3-42)), so this is all guesswork. |
|
|
479 | sub _decode_real_decimal { |
|
|
480 | my ($format, $val) = @_; |
|
|
481 | |
|
|
482 | $val =~ y/,/./; # probably not in ISO-6093 |
|
|
483 | |
|
|
484 | if ($format == 1) { |
|
|
485 | $val =~ /^ \ * [+-]? [0-9]+ \z/x |
|
|
486 | or Carp::croak "BER_TYPE_REAL NR1 value not in NR1 format ($val) (X.690 8.5.8)"; |
|
|
487 | } elsif ($format == 2) { |
|
|
488 | $val =~ /^ \ * [+-]? (?: [0-9]+\.[0-9]* | [0-9]*\.[0-9]+ ) \z/x |
|
|
489 | or Carp::croak "BER_TYPE_REAL NR2 value not in NR2 format ($val) (X.690 8.5.8)"; |
|
|
490 | } elsif ($format == 3) { |
|
|
491 | $val =~ /^ \ * [+-] (?: [0-9]+\.[0-9]* | [0-9]*\.[0-9]+ ) [eE] [+-]? [0-9]+ \z/x |
|
|
492 | or Carp::croak "BER_TYPE_REAL NR3 value not in NR3 format ($val) (X.690 8.5.8)"; |
|
|
493 | } else { |
|
|
494 | Carp::croak "BER_TYPE_REAL invalid decimal numerical representation format $format"; |
|
|
495 | } |
|
|
496 | |
|
|
497 | $val |
|
|
498 | } |
|
|
499 | |
|
|
500 | # this is a mess, but perl's support for floating point formatting is nearly nonexistant |
|
|
501 | sub _encode_real_decimal { |
|
|
502 | my ($val, $nvdig) = @_; |
|
|
503 | |
|
|
504 | $val = sprintf "%.*G", $nvdig + 1, $val; |
|
|
505 | |
|
|
506 | if ($val =~ /E/) { |
|
|
507 | $val =~ s/E(?=[^+-])/E+/; |
|
|
508 | $val =~ s/E/.E/ if $val !~ /\./; |
|
|
509 | $val =~ s/^/+/ unless $val =~ /^-/; |
|
|
510 | |
|
|
511 | return "\x03$val" # NR3 |
|
|
512 | } |
|
|
513 | |
|
|
514 | $val =~ /\./ |
|
|
515 | ? "\x02$val" # NR2 |
|
|
516 | : "\x01$val" # NR1 |
|
|
517 | } |
|
|
518 | |
|
|
519 | =head2 DEBUGGING |
|
|
520 | |
|
|
521 | To aid debugging, you can call the C<ber_dump> function to print a "nice" |
|
|
522 | representation to STDOUT. |
|
|
523 | |
|
|
524 | =over |
|
|
525 | |
|
|
526 | =item ber_dump $tuple[, $profile[, $prefix]] |
|
|
527 | |
|
|
528 | In addition to specifying the BER C<$tuple> to dump, you can also specify |
|
|
529 | a C<$profile> and a C<$prefix> string that is printed in front of each line. |
|
|
530 | |
|
|
531 | If C<$profile> is C<$Convert::BER::XS::SNMP_PROFILE>, then C<ber_dump> |
|
|
532 | will try to improve its output for SNMP data. |
|
|
533 | |
|
|
534 | The output usually contains three columns, the "human readable" tag, the |
|
|
535 | BER type used to decode it, and the data value. |
|
|
536 | |
|
|
537 | This function is somewhat slow and uses a number of heuristics and tricks, |
|
|
538 | so it really is only suitable for debug prints. |
|
|
539 | |
|
|
540 | Example output: |
|
|
541 | |
|
|
542 | SEQUENCE |
|
|
543 | | OCTET_STRING bytes 800063784300454045045400000001 |
|
|
544 | | OCTET_STRING bytes |
|
|
545 | | CONTEXT (7) CONSTRUCTED |
|
|
546 | | | INTEGER int 1058588941 |
|
|
547 | | | INTEGER int 0 |
|
|
548 | | | INTEGER int 0 |
|
|
549 | | | SEQUENCE |
|
|
550 | | | | SEQUENCE |
|
|
551 | | | | | OID oid 1.3.6.1.2.1.1.3.0 |
|
|
552 | | | | | TIMETICKS int 638085796 |
|
|
553 | |
|
|
554 | =back |
|
|
555 | |
|
|
556 | =cut |
|
|
557 | |
|
|
558 | # reverse enum, very slow and ugly hack |
|
|
559 | sub _re { |
|
|
560 | my ($export_tag, $value) = @_; |
|
|
561 | |
|
|
562 | for my $symbol (@{ $EXPORT_TAGS{$export_tag} }) { |
|
|
563 | $value == eval $symbol |
|
|
564 | and return $symbol; |
|
|
565 | } |
|
|
566 | |
|
|
567 | "($value)" |
|
|
568 | } |
|
|
569 | |
|
|
570 | sub _ber_dump { |
|
|
571 | my ($ber, $profile, $indent) = @_; |
|
|
572 | |
|
|
573 | if (my $seq = ber_is_seq $ber) { |
|
|
574 | printf "%sSEQUENCE\n", $indent; |
|
|
575 | &_ber_dump ($_, $profile, "$indent| ") |
|
|
576 | for @$seq; |
|
|
577 | } else { |
|
|
578 | my $asn = $ber->[BER_CLASS] == ASN_UNIVERSAL; |
|
|
579 | |
|
|
580 | my $class = _re const_asn_class => $ber->[BER_CLASS]; |
|
|
581 | my $tag = $asn ? _re const_asn_tag => $ber->[BER_TAG] : $ber->[BER_TAG]; |
|
|
582 | my $type = _re const_ber_type => $profile->get ($ber->[BER_CLASS], $ber->[BER_TAG]); |
|
|
583 | my $data = $ber->[BER_DATA]; |
|
|
584 | |
|
|
585 | if ($profile == $SNMP_PROFILE and $ber->[BER_CLASS] == ASN_APPLICATION) { |
|
|
586 | $tag = _re const_snmp => $ber->[BER_TAG]; |
|
|
587 | } elsif (!$asn) { |
|
|
588 | $tag = "$class ($tag)"; |
|
|
589 | } |
|
|
590 | |
|
|
591 | $class =~ s/^ASN_//; |
|
|
592 | $tag =~ s/^(ASN_|SNMP_)//; |
|
|
593 | $type =~ s/^BER_TYPE_//; |
|
|
594 | |
|
|
595 | if ($ber->[BER_FLAGS]) { |
|
|
596 | printf "$indent%-16.16s\n", $tag; |
|
|
597 | &_ber_dump ($_, $profile, "$indent| ") |
|
|
598 | for @$data; |
|
|
599 | } else { |
|
|
600 | if ($data =~ y/\x20-\x7e//c / (length $data || 1) > 0.2 or $data =~ /\x00./s) { |
|
|
601 | # assume binary |
|
|
602 | $data = unpack "H*", $data; |
|
|
603 | } else { |
|
|
604 | $data =~ s/[^\x20-\x7e]/./g; |
|
|
605 | $data = "\"$data\"" if $tag =~ /string/i || !length $data; |
|
|
606 | } |
|
|
607 | |
|
|
608 | substr $data, 40, 1e9, "..." if 40 < length $data; |
|
|
609 | |
|
|
610 | printf "$indent%-16.16s %-6.6s %s\n", $tag, lc $type, $data; |
|
|
611 | } |
|
|
612 | } |
|
|
613 | } |
|
|
614 | |
|
|
615 | sub ber_dump($;$$) { |
|
|
616 | _ber_dump $_[0], $_[1] || $DEFAULT_PROFILE, $_[2]; |
|
|
617 | } |
440 | |
618 | |
441 | =head1 PROFILES |
619 | =head1 PROFILES |
442 | |
620 | |
443 | While any BER data can be correctly encoded and decoded out of the box, it |
621 | While any BER data can be correctly encoded and decoded out of the box, it |
444 | can be inconvenient to have to manually decode some values into a "better" |
622 | can be inconvenient to have to manually decode some values into a "better" |
… | |
… | |
470 | =item C<$Convert::BER::XS::SNMP_PROFILE> |
648 | =item C<$Convert::BER::XS::SNMP_PROFILE> |
471 | |
649 | |
472 | A profile with mappings for SNMP-specific application tags added. This is |
650 | A profile with mappings for SNMP-specific application tags added. This is |
473 | useful when de-/encoding SNMP data. |
651 | useful when de-/encoding SNMP data. |
474 | |
652 | |
|
|
653 | The L<Example Profile> section, below, shows how this profile is being |
|
|
654 | constructed. |
|
|
655 | |
475 | Example: |
656 | Example: |
476 | |
657 | |
477 | $ber = ber_decode $data, $Convert::BER::XS::SNMP_PROFILE; |
658 | $ber = ber_decode $data, $Convert::BER::XS::SNMP_PROFILE; |
478 | |
659 | |
479 | =back |
660 | =back |
… | |
… | |
505 | |
686 | |
506 | Returns the BER type mapped to the given C<$class>/C<$tag> combination. |
687 | Returns the BER type mapped to the given C<$class>/C<$tag> combination. |
507 | |
688 | |
508 | =back |
689 | =back |
509 | |
690 | |
510 | =head2 BER TYPES |
691 | =head2 BER Types |
511 | |
692 | |
512 | This lists the predefined BER types - you can map any C<CLASS>/C<TAG> |
693 | This lists the predefined BER types. BER types are formatters used |
513 | combination to any C<BER_TYPE_*>. |
694 | internally to format and encode BER values. You can assign any C<BER_TYPE> |
|
|
695 | to any C<CLASS>/C<TAG> combination tgo change how that tag is decoded or |
|
|
696 | encoded. |
514 | |
697 | |
515 | =over |
698 | =over |
516 | |
699 | |
517 | =item C<BER_TYPE_BYTES> |
700 | =item C<BER_TYPE_BYTES> |
518 | |
701 | |
… | |
… | |
547 | dot, e.g. C<1.3.6.1.213>. |
730 | dot, e.g. C<1.3.6.1.213>. |
548 | |
731 | |
549 | =item C<BER_TYPE_RELOID> |
732 | =item C<BER_TYPE_RELOID> |
550 | |
733 | |
551 | Same as C<BER_TYPE_OID> but uses relative object identifier |
734 | Same as C<BER_TYPE_OID> but uses relative object identifier |
552 | encoding: ASN.1 has this hack of encoding the first two OID components |
735 | encoding: ASN.1 uses some hack encoding of the first two OID components |
553 | into a single integer in a weird attempt to save an insignificant amount |
736 | into a single integer in a weird attempt to save an insignificant amount |
554 | of space in an otherwise wasteful encoding, and relative OIDs are |
737 | of space in an otherwise wasteful encoding, and relative OIDs are |
555 | basically OIDs without this hack. The practical difference is that the |
738 | basically OIDs without this hack. The practical difference is that the |
556 | second component of an OID can only have the values 1..40, while relative |
739 | second component of an OID can only have the values 1..40, while relative |
557 | OIDs do not have this restriction. |
740 | OIDs do not have this restriction. |
… | |
… | |
595 | |
778 | |
596 | $SNMP_PROFILE->set (ASN_APPLICATION, SNMP_IPADDRESS , BER_TYPE_IPADDRESS); |
779 | $SNMP_PROFILE->set (ASN_APPLICATION, SNMP_IPADDRESS , BER_TYPE_IPADDRESS); |
597 | $SNMP_PROFILE->set (ASN_APPLICATION, SNMP_COUNTER32 , BER_TYPE_INT); |
780 | $SNMP_PROFILE->set (ASN_APPLICATION, SNMP_COUNTER32 , BER_TYPE_INT); |
598 | $SNMP_PROFILE->set (ASN_APPLICATION, SNMP_UNSIGNED32, BER_TYPE_INT); |
781 | $SNMP_PROFILE->set (ASN_APPLICATION, SNMP_UNSIGNED32, BER_TYPE_INT); |
599 | $SNMP_PROFILE->set (ASN_APPLICATION, SNMP_TIMETICKS , BER_TYPE_INT); |
782 | $SNMP_PROFILE->set (ASN_APPLICATION, SNMP_TIMETICKS , BER_TYPE_INT); |
600 | $SNMP_PROFILE->set (ASN_APPLICATION, SNMP_OPAQUE , BER_TYPE_IPADDRESS); |
783 | $SNMP_PROFILE->set (ASN_APPLICATION, SNMP_OPAQUE , BER_TYPE_BYTES); |
601 | $SNMP_PROFILE->set (ASN_APPLICATION, SNMP_COUNTER64 , BER_TYPE_INT); |
784 | $SNMP_PROFILE->set (ASN_APPLICATION, SNMP_COUNTER64 , BER_TYPE_INT); |
602 | |
785 | |
603 | =cut |
|
|
604 | |
|
|
605 | our $DEFAULT_PROFILE = new Convert::BER::XS::Profile; |
|
|
606 | |
|
|
607 | $DEFAULT_PROFILE->_set_default; |
|
|
608 | |
|
|
609 | # additional SNMP application types |
|
|
610 | our $SNMP_PROFILE = new Convert::BER::XS::Profile; |
|
|
611 | |
|
|
612 | $SNMP_PROFILE->set (ASN_APPLICATION, SNMP_IPADDRESS , BER_TYPE_IPADDRESS); |
|
|
613 | $SNMP_PROFILE->set (ASN_APPLICATION, SNMP_COUNTER32 , BER_TYPE_INT); |
|
|
614 | $SNMP_PROFILE->set (ASN_APPLICATION, SNMP_UNSIGNED32, BER_TYPE_INT); |
|
|
615 | $SNMP_PROFILE->set (ASN_APPLICATION, SNMP_TIMETICKS , BER_TYPE_INT); |
|
|
616 | $SNMP_PROFILE->set (ASN_APPLICATION, SNMP_OPAQUE , BER_TYPE_IPADDRESS); |
|
|
617 | $SNMP_PROFILE->set (ASN_APPLICATION, SNMP_COUNTER64 , BER_TYPE_INT); |
|
|
618 | |
|
|
619 | 1; |
|
|
620 | |
|
|
621 | =head2 LIMITATIONS/NOTES |
786 | =head2 LIMITATIONS/NOTES |
622 | |
787 | |
623 | This module can only en-/decode 64 bit signed and unsigned integers, and |
788 | This module can only en-/decode 64 bit signed and unsigned |
624 | only when your perl supports those. |
789 | integers/tags/lengths, and only when your perl supports those. So no UUID |
|
|
790 | OIDs for now (unless you map the C<OBJECT IDENTIFIER> tag to something |
|
|
791 | other than C<BER_TYPE_OID>). |
625 | |
792 | |
626 | This module does not generally care about ranges, i.e. it will happily |
793 | This module does not generally care about ranges, i.e. it will happily |
627 | de-/encode 64 bit integers into an C<ASN_INTEGER> value, or a negative |
794 | de-/encode 64 bit integers into an C<SNMP_UNSIGNED32> value, or a negative |
628 | number into an C<SNMP_COUNTER64>. |
795 | number into an C<SNMP_COUNTER64>. |
629 | |
796 | |
630 | OBJECT IDENTIFIEERs cannot have unlimited length, although the limit is |
797 | OBJECT IDENTIFIEERs cannot have unlimited length, although the limit is |
631 | much larger than e.g. the one imposed by SNMP or other protocols,a nd is |
798 | much larger than e.g. the one imposed by SNMP or other protocols, and is |
632 | about 4kB. |
799 | about 4kB. |
633 | |
|
|
634 | Indefinite length encoding is not supported. |
|
|
635 | |
800 | |
636 | Constructed strings are decoded just fine, but there should be a way to |
801 | Constructed strings are decoded just fine, but there should be a way to |
637 | join them for convenience. |
802 | join them for convenience. |
638 | |
803 | |
639 | REAL values are not supported and will currently croak. |
804 | REAL values will always be encoded in decimal form and ssometimes is |
640 | |
805 | forced into a perl "NV" type, potentially losing precision. |
641 | The encoder and decoder tend to accept more formats than should be |
|
|
642 | strictly supported. |
|
|
643 | |
|
|
644 | This module has undergone little to no testing so far. |
|
|
645 | |
806 | |
646 | =head2 ITHREADS SUPPORT |
807 | =head2 ITHREADS SUPPORT |
647 | |
808 | |
648 | This module is unlikely to work when the (officially discouraged) ithreads |
809 | This module is unlikely to work in any other than the loading thread when |
649 | are in use. |
810 | the (officially discouraged) ithreads are in use. |
650 | |
811 | |
651 | =head1 AUTHOR |
812 | =head1 AUTHOR |
652 | |
813 | |
653 | Marc Lehmann <schmorp@schmorp.de> |
814 | Marc Lehmann <schmorp@schmorp.de> |
654 | http://software.schmorp.de/pkg/Convert-BER-XS |
815 | http://software.schmorp.de/pkg/Convert-BER-XS |
655 | |
816 | |
656 | =cut |
817 | =cut |
657 | |
818 | |
|
|
819 | 1; |
|
|
820 | |