… | |
… | |
73 | This module implements a I<very> low level BER/DER en-/decoder. |
73 | This module implements a I<very> low level BER/DER en-/decoder. |
74 | |
74 | |
75 | If is tuned for low memory and high speed, while still maintaining some |
75 | If is tuned for low memory and high speed, while still maintaining some |
76 | level of user-friendlyness. |
76 | level of user-friendlyness. |
77 | |
77 | |
78 | Currently, not much is documented, as this is an initial release to |
78 | =head2 EXPORT TAGS AND CONSTANTS |
79 | reserve CPAN namespace, stay tuned for a few days. |
79 | |
|
|
80 | By default this module doesn't export any symbols, but if you don't want |
|
|
81 | to break your keyboard, editor or eyesigh with extreemly long names, I |
|
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82 | recommend importing the C<:all> tag. Still, you can selectively import |
|
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83 | things: |
|
|
84 | |
|
|
85 | =over |
|
|
86 | |
|
|
87 | =item :all |
|
|
88 | |
|
|
89 | All of the below. Really. Rcommended for at least first steps, or if you |
|
|
90 | don't care about a few kilobytes of wasted memory (and namespace). |
|
|
91 | |
|
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92 | =item :const |
|
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93 | |
|
|
94 | All of the stricly ASN.1-related constants defined by this module, the |
|
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95 | same as C<:const_asn :const_index>. Notably, this does not contain |
|
|
96 | C<:const_ber_type> and C<:const_snmp>. |
|
|
97 | |
|
|
98 | A good set to get everything you need to decode and match BER data would be |
|
|
99 | C<:decode :const>. |
|
|
100 | |
|
|
101 | =item C<:const_index>> |
|
|
102 | |
|
|
103 | The BER tuple array index constants: |
|
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104 | |
|
|
105 | BER_CLASS BER_TAG BER_CONSTRUCTED BER_DATA |
|
|
106 | |
|
|
107 | =item C<:const_asn> |
|
|
108 | |
|
|
109 | ASN class values (these are C<0>, C<1>, C<2> and C<3>, reespectively - |
|
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110 | exactly thw two topmost bits from the identifdier octet shifted 6 bits to |
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111 | the right): |
|
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112 | |
|
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113 | ASN_UNIVERSAL ASN_APPLICATION ASN_CONTEXT ASN_PRIVATE |
|
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114 | |
|
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115 | ASN tag values (some of which are aliases, such as C<ASN_OID>). Their |
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116 | numerical value corresponds exactly to the numbers used in BER/X.690. |
|
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117 | |
|
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118 | ASN_BOOLEAN ASN_INTEGER32 ASN_BIT_STRING ASN_OCTET_STRING ASN_NULL ASN_OBJECT_IDENTIFIER |
|
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119 | ASN_OBJECT_DESCRIPTOR ASN_OID ASN_EXTERNAL ASN_REAL ASN_SEQUENCE ASN_ENUMERATED |
|
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120 | 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 |
|
|
122 | 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 |
|
|
124 | |
|
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125 | =item C<:const_ber_type> |
|
|
126 | |
|
|
127 | The BER type constants, explained in the PROFILES section. |
|
|
128 | |
|
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129 | BER_TYPE_BYTES BER_TYPE_UTF8 BER_TYPE_UCS2 BER_TYPE_UCS4 BER_TYPE_INT |
|
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130 | BER_TYPE_OID BER_TYPE_RELOID BER_TYPE_NULL BER_TYPE_BOOL BER_TYPE_REAL |
|
|
131 | BER_TYPE_IPADDRESS BER_TYPE_CROAK |
|
|
132 | |
|
|
133 | =item C<:const_snmp> |
|
|
134 | |
|
|
135 | Constants only relevant to SNMP. These are the tag values used by SNMP in |
|
|
136 | the C<ASN_APPLICATION> namespace and have the exact numerical value as in |
|
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137 | BER/RFC 2578. |
|
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138 | |
|
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139 | SNMP_IPADDRESS SNMP_COUNTER32 SNMP_UNSIGNED32 SNMP_TIMETICKS SNMP_OPAQUE SNMP_COUNTER64 |
|
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140 | |
|
|
141 | =item C<:decode> |
|
|
142 | |
|
|
143 | C<ber_decode> and the match helper functions: |
|
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144 | |
|
|
145 | ber_decode ber_is ber_is_seq ber_is_i32 ber_is_oid |
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146 | |
|
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147 | =item C<:encode> |
|
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148 | |
|
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149 | C<ber_encode> and the construction helper functions: |
|
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150 | |
|
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151 | ber_encode ber_i32 |
|
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152 | |
|
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153 | =back |
80 | |
154 | |
81 | =head2 ASN.1/BER/DER/... BASICS |
155 | =head2 ASN.1/BER/DER/... BASICS |
82 | |
156 | |
83 | ASN.1 is a strange language that can be sed to describe protocols and |
157 | ASN.1 is a strange language that can be used to describe protocols and |
84 | data structures. It supports various mappings to JSON, XML, but most |
158 | data structures. It supports various mappings to JSON, XML, but most |
85 | importantly, to a various binary encodings such as BER, that is the topic |
159 | importantly, to a various binary encodings such as BER, that is the topic |
86 | of this module, and is used in SNMP or LDAP for example. |
160 | of this module, and is used in SNMP or LDAP for example. |
87 | |
161 | |
88 | While ASN.1 defines a schema that is useful to interpret encoded data, |
162 | While ASN.1 defines a schema that is useful to interpret encoded data, |
… | |
… | |
90 | whether something is a string or a number or a sequence or something else, |
164 | whether something is a string or a number or a sequence or something else, |
91 | but you can nevertheless decode the overall structure, even if you end up |
165 | but you can nevertheless decode the overall structure, even if you end up |
92 | with just a binary blob for the actual value. |
166 | with just a binary blob for the actual value. |
93 | |
167 | |
94 | This works because BER values are tagged with a type and a namespace, |
168 | This works because BER values are tagged with a type and a namespace, |
95 | and also have a flag that says whther a value consists of subvalues (is |
169 | and also have a flag that says whether a value consists of subvalues (is |
96 | "constructed") or not (is "primitive"). |
170 | "constructed") or not (is "primitive"). |
97 | |
171 | |
98 | Tags are simple integers, and ASN.1 defines a somewhat weird assortment of |
172 | Tags are simple integers, and ASN.1 defines a somewhat weird assortment of |
99 | those - for example, you have 32 bit signed integers and 16(!) different |
173 | those - for example, you have 32 bit signed integers and 16(!) different |
100 | string types, but there is no unsigned32 type for example. Different |
174 | string types, but there is no unsigned32 type for example. Different |
… | |
… | |
292 | use Exporter qw(import); |
366 | use Exporter qw(import); |
293 | |
367 | |
294 | our $VERSION; |
368 | our $VERSION; |
295 | |
369 | |
296 | BEGIN { |
370 | BEGIN { |
297 | $VERSION = 0.7; |
371 | $VERSION = 0.8; |
298 | XSLoader::load __PACKAGE__, $VERSION; |
372 | XSLoader::load __PACKAGE__, $VERSION; |
299 | } |
373 | } |
300 | |
374 | |
301 | our %EXPORT_TAGS = ( |
375 | our %EXPORT_TAGS = ( |
302 | const => [qw( |
376 | const_index => [qw( |
303 | BER_CLASS BER_TAG BER_CONSTRUCTED BER_DATA |
377 | BER_CLASS BER_TAG BER_CONSTRUCTED BER_DATA |
304 | |
378 | )], |
|
|
379 | const_asn => [qw( |
305 | ASN_BOOLEAN ASN_INTEGER32 ASN_BIT_STRING ASN_OCTET_STRING ASN_NULL ASN_OBJECT_IDENTIFIER |
380 | ASN_BOOLEAN ASN_INTEGER32 ASN_BIT_STRING ASN_OCTET_STRING ASN_NULL ASN_OBJECT_IDENTIFIER |
306 | ASN_OBJECT_DESCRIPTOR ASN_OID ASN_EXTERNAL ASN_REAL ASN_SEQUENCE ASN_ENUMERATED |
381 | ASN_OBJECT_DESCRIPTOR ASN_OID ASN_EXTERNAL ASN_REAL ASN_SEQUENCE ASN_ENUMERATED |
307 | ASN_EMBEDDED_PDV ASN_UTF8_STRING ASN_RELATIVE_OID ASN_SET ASN_NUMERIC_STRING |
382 | ASN_EMBEDDED_PDV ASN_UTF8_STRING ASN_RELATIVE_OID ASN_SET ASN_NUMERIC_STRING |
308 | ASN_PRINTABLE_STRING ASN_TELETEX_STRING ASN_T61_STRING ASN_VIDEOTEX_STRING ASN_IA5_STRING |
383 | ASN_PRINTABLE_STRING ASN_TELETEX_STRING ASN_T61_STRING ASN_VIDEOTEX_STRING ASN_IA5_STRING |
309 | ASN_ASCII_STRING ASN_UTC_TIME ASN_GENERALIZED_TIME ASN_GRAPHIC_STRING ASN_VISIBLE_STRING |
384 | ASN_ASCII_STRING ASN_UTC_TIME ASN_GENERALIZED_TIME ASN_GRAPHIC_STRING ASN_VISIBLE_STRING |
310 | ASN_ISO646_STRING ASN_GENERAL_STRING ASN_UNIVERSAL_STRING ASN_CHARACTER_STRING ASN_BMP_STRING |
385 | ASN_ISO646_STRING ASN_GENERAL_STRING ASN_UNIVERSAL_STRING ASN_CHARACTER_STRING ASN_BMP_STRING |
311 | |
386 | |
312 | ASN_UNIVERSAL ASN_APPLICATION ASN_CONTEXT ASN_PRIVATE |
387 | ASN_UNIVERSAL ASN_APPLICATION ASN_CONTEXT ASN_PRIVATE |
313 | |
388 | )], |
|
|
389 | const_ber_type => [qw( |
314 | BER_TYPE_BYTES BER_TYPE_UTF8 BER_TYPE_UCS2 BER_TYPE_UCS4 BER_TYPE_INT |
390 | BER_TYPE_BYTES BER_TYPE_UTF8 BER_TYPE_UCS2 BER_TYPE_UCS4 BER_TYPE_INT |
315 | BER_TYPE_OID BER_TYPE_RELOID BER_TYPE_NULL BER_TYPE_BOOL BER_TYPE_REAL |
391 | BER_TYPE_OID BER_TYPE_RELOID BER_TYPE_NULL BER_TYPE_BOOL BER_TYPE_REAL |
316 | BER_TYPE_IPADDRESS BER_TYPE_CROAK |
392 | BER_TYPE_IPADDRESS BER_TYPE_CROAK |
317 | )], |
393 | )], |
318 | const_snmp => [qw( |
394 | const_snmp => [qw( |
319 | SNMP_IPADDRESS SNMP_COUNTER32 SNMP_UNSIGNED32 SNMP_TIMETICKS SNMP_OPAQUE SNMP_COUNTER64 |
395 | SNMP_IPADDRESS SNMP_COUNTER32 SNMP_UNSIGNED32 SNMP_TIMETICKS SNMP_OPAQUE SNMP_COUNTER64 |
320 | )], |
396 | )], |
321 | encode => [qw( |
397 | decode => [qw( |
322 | ber_decode |
398 | ber_decode |
323 | ber_is ber_is_seq ber_is_i32 ber_is_oid |
399 | ber_is ber_is_seq ber_is_i32 ber_is_oid |
324 | )], |
400 | )], |
325 | decode => [qw( |
401 | encode => [qw( |
326 | ber_encode |
402 | ber_encode |
327 | ber_i32 |
403 | ber_i32 |
328 | )], |
404 | )], |
329 | ); |
405 | ); |
330 | |
406 | |
331 | our @EXPORT_OK = map @$_, values %EXPORT_TAGS; |
407 | our @EXPORT_OK = map @$_, values %EXPORT_TAGS; |
332 | |
408 | |
333 | $EXPORT_TAGS{all} = \@EXPORT_OK; |
409 | $EXPORT_TAGS{all} = \@EXPORT_OK; |
|
|
410 | $EXPORT_TAGS{const} = [map @{ $EXPORT_TAGS{$_} }, qw(const_index const_asn)]; |
|
|
411 | use Data::Dump; ddx \%EXPORT_TAGS; |
334 | |
412 | |
335 | =head1 PROFILES |
413 | =head1 PROFILES |
336 | |
414 | |
337 | While any BER data can be correctly encoded and decoded out of the box, it |
415 | While any BER data can be correctly encoded and decoded out of the box, it |
338 | can be inconvenient to have to manually decode some values into a "better" |
416 | can be inconvenient to have to manually decode some values into a "better" |
… | |
… | |
347 | |
425 | |
348 | The default profile supports the standard ASN.1 types, but no |
426 | The default profile supports the standard ASN.1 types, but no |
349 | application-specific ones. This means that class/tag combinations not in |
427 | application-specific ones. This means that class/tag combinations not in |
350 | the base set of ASN.1 are decoded into their raw octet strings. |
428 | the base set of ASN.1 are decoded into their raw octet strings. |
351 | |
429 | |
352 | C<Convert::BER::XS> defines two profile variables you cna use out of the box: |
430 | C<Convert::BER::XS> defines two profile variables you can use out of the box: |
353 | |
431 | |
354 | =over |
432 | =over |
355 | |
433 | |
356 | =item C<$Convert::BER::XS::DEFAULT_PROFILE> |
434 | =item C<$Convert::BER::XS::DEFAULT_PROFILE> |
357 | |
435 | |
358 | This is the default profile, i.e. the profile that is used when no |
436 | This is the default profile, i.e. the profile that is used when no |
359 | profile is specified for de-/encoding. |
437 | profile is specified for de-/encoding. |
360 | |
438 | |
361 | You cna modify it, but remember that this modifies the defaults for all |
439 | You can modify it, but remember that this modifies the defaults for all |
362 | callers that rely on the defauit profile. |
440 | callers that rely on the default profile. |
363 | |
441 | |
364 | =item C<$Convert::BER::XS::SNMP_PROFILE> |
442 | =item C<$Convert::BER::XS::SNMP_PROFILE> |
365 | |
443 | |
366 | A profile with mappings for SNMP-specific application tags added. This is |
444 | A profile with mappings for SNMP-specific application tags added. This is |
367 | useful when de-/encoding SNMP data. |
445 | useful when de-/encoding SNMP data. |
368 | |
446 | |
369 | Example: |
447 | Example: |
|
|
448 | |
370 | $ber = ber_decode $data, $Convert::BER::XS::SNMP_PROFILE; |
449 | $ber = ber_decode $data, $Convert::BER::XS::SNMP_PROFILE; |
371 | |
450 | |
372 | =back |
451 | =back |
373 | |
452 | |
374 | =head2 The Convert::BER::XS::Profile class |
453 | =head2 The Convert::BER::XS::Profile class |
… | |
… | |
387 | |
466 | |
388 | Note that currently, the mapping is stored in a flat array, so large |
467 | Note that currently, the mapping is stored in a flat array, so large |
389 | values of C<$tag> will consume large amounts of memory. |
468 | values of C<$tag> will consume large amounts of memory. |
390 | |
469 | |
391 | Example: |
470 | Example: |
|
|
471 | |
392 | $profile = new Convert::BER::XS::Profile; |
472 | $profile = new Convert::BER::XS::Profile; |
393 | $profile->set (ASN_APPLICATION, SNMP_COUNTER32, BER_TYPE_INT); |
473 | $profile->set (ASN_APPLICATION, SNMP_COUNTER32, BER_TYPE_INT); |
394 | $ber = ber_decode $data, $profile; |
474 | $ber = ber_decode $data, $profile; |
395 | |
475 | |
396 | =item $type = $profile->get ($class, $tag) |
476 | =item $type = $profile->get ($class, $tag) |
… | |
… | |
438 | Encodes and decodes an OBJECT IDENTIFIER into dotted form without leading |
518 | Encodes and decodes an OBJECT IDENTIFIER into dotted form without leading |
439 | dot, e.g. C<1.3.6.1.213>. |
519 | dot, e.g. C<1.3.6.1.213>. |
440 | |
520 | |
441 | =item C<BER_TYPE_RELOID> |
521 | =item C<BER_TYPE_RELOID> |
442 | |
522 | |
443 | Same as C<BER_TYPE_OID> but uses relative OID encoding: ASN.1 has this |
523 | Same as C<BER_TYPE_OID> but uses relative object identifier |
444 | hack of encoding the first two OID components into a single integer in a |
524 | encoding: ASN.1 has this hack of encoding the first two OID components |
445 | weird attempt to save an insignificant amount of space in an otherwise |
525 | into a single integer in a weird attempt to save an insignificant amount |
446 | wasteful encoding, and relative OIDs are basically OIDs without this |
526 | of space in an otherwise wasteful encoding, and relative OIDs are |
447 | hack. The practical difference is that the second component of an OID |
527 | basically OIDs without this hack. The practical difference is that the |
448 | can only have the values 1..40, while relative OIDs do not have this |
528 | second component of an OID can only have the values 1..40, while relative |
449 | restriction. |
529 | OIDs do not have this restriction. |
450 | |
530 | |
451 | =item C<BER_TYPE_NULL> |
531 | =item C<BER_TYPE_NULL> |
452 | |
532 | |
453 | Decodes an C<ASN_NULL> value into C<undef>, and always encodes a |
533 | Decodes an C<ASN_NULL> value into C<undef>, and always encodes a |
454 | C<ASN_NULL> type, regardless of the perl value. |
534 | C<ASN_NULL> type, regardless of the perl value. |
… | |
… | |
462 | |
542 | |
463 | Decodes/encodes a BER real value. NOT IMPLEMENTED. |
543 | Decodes/encodes a BER real value. NOT IMPLEMENTED. |
464 | |
544 | |
465 | =item C<BER_TYPE_IPADDRESS> |
545 | =item C<BER_TYPE_IPADDRESS> |
466 | |
546 | |
467 | Decodes/encodes a four byte string into an IOv4 dotted-quad address string |
547 | Decodes/encodes a four byte string into an IPv4 dotted-quad address string |
468 | in perl. Given ther obsolete nature of this type, this is a low-effort |
548 | in Perl. Given the obsolete nature of this type, this is a low-effort |
469 | implementation that simply uses C<sprintf> and C<sscanf>-style conversion, |
549 | implementation that simply uses C<sprintf> and C<sscanf>-style conversion, |
470 | so it won't handle all string forms supported by C<inet_aton>. |
550 | so it won't handle all string forms supported by C<inet_aton> for example. |
471 | |
551 | |
472 | =item C<BER_TYPE_CROAK> |
552 | =item C<BER_TYPE_CROAK> |
473 | |
553 | |
474 | Always croaks when encountered during encoding or decoding - the |
554 | Always croaks when encountered during encoding or decoding - the |
475 | default behaviour when encountering an unknown type is to treat it as |
555 | default behaviour when encountering an unknown type is to treat it as |
476 | C<BER_TYPE_BYTES>. When you don't want that but instead prefer a hard |
556 | C<BER_TYPE_BYTES>. When you don't want that but instead prefer a hard |
477 | error for some types, then CyBER_TYPE_CROAK> is for you. |
557 | error for some types, then C<BER_TYPE_CROAK> is for you. |
478 | |
558 | |
479 | =back |
559 | =back |
480 | |
560 | |
481 | =cut |
561 | =cut |
482 | |
562 | |
483 | our $DEFAULT_PROFILE = new Convert::BER::XS::Profile; |
563 | our $DEFAULT_PROFILE = new Convert::BER::XS::Profile; |
484 | our $SNMP_PROFILE = new Convert::BER::XS::Profile; |
564 | our $SNMP_PROFILE = new Convert::BER::XS::Profile; |
485 | |
565 | |
|
|
566 | # additional SNMP application types |
486 | $SNMP_PROFILE->set (ASN_APPLICATION, SNMP_IPADDRESS , BER_TYPE_IPADDRESS); |
567 | $SNMP_PROFILE->set (ASN_APPLICATION, SNMP_IPADDRESS , BER_TYPE_IPADDRESS); |
487 | $SNMP_PROFILE->set (ASN_APPLICATION, SNMP_COUNTER32 , BER_TYPE_INT); |
568 | $SNMP_PROFILE->set (ASN_APPLICATION, SNMP_COUNTER32 , BER_TYPE_INT); |
488 | $SNMP_PROFILE->set (ASN_APPLICATION, SNMP_UNSIGNED32, BER_TYPE_INT); |
569 | $SNMP_PROFILE->set (ASN_APPLICATION, SNMP_UNSIGNED32, BER_TYPE_INT); |
489 | $SNMP_PROFILE->set (ASN_APPLICATION, SNMP_TIMETICKS , BER_TYPE_INT); |
570 | $SNMP_PROFILE->set (ASN_APPLICATION, SNMP_TIMETICKS , BER_TYPE_INT); |
490 | $SNMP_PROFILE->set (ASN_APPLICATION, SNMP_OPAQUE , BER_TYPE_IPADDRESS); |
571 | $SNMP_PROFILE->set (ASN_APPLICATION, SNMP_OPAQUE , BER_TYPE_IPADDRESS); |
… | |
… | |
492 | |
573 | |
493 | $DEFAULT_PROFILE->_set_default; |
574 | $DEFAULT_PROFILE->_set_default; |
494 | |
575 | |
495 | 1; |
576 | 1; |
496 | |
577 | |
497 | =head2 LIMITATIONS |
578 | =head2 LIMITATIONS/NOTES |
498 | |
579 | |
499 | This module can only en-/decode 64 bit signed and unsigned integers, and |
580 | This module can only en-/decode 64 bit signed and unsigned integers, and |
500 | only when your perl supports those. |
581 | only when your perl supports those. |
501 | |
582 | |
|
|
583 | This module does not generally care about ranges, i.e. it will happily |
|
|
584 | de-/encode 64 bit integers into an C<ASN_INTEGER32> value, or a negative |
|
|
585 | number into an C<SNMP_COUNTER64>. |
|
|
586 | |
502 | OBJECT IDENTIFIEERS cannot have unlimited length, although the limit is |
587 | OBJECT IDENTIFIEERs cannot have unlimited length, although the limit is |
503 | much larger than e.g. the one imposed by SNMP or other protocols. |
588 | much larger than e.g. the one imposed by SNMP or other protocols,a nd is |
|
|
589 | about 4kB. |
504 | |
590 | |
505 | REAL values are not supported and will croak. |
591 | REAL values are not supported and will currently croak. |
506 | |
592 | |
507 | This module has undergone little to no testing so far. |
593 | This module has undergone little to no testing so far. |
|
|
594 | |
|
|
595 | =head2 ITHREADS SUPPORT |
|
|
596 | |
|
|
597 | This module is unlikely to work when the (officially discouraged) ithreads |
|
|
598 | are in use. |
508 | |
599 | |
509 | =head1 AUTHOR |
600 | =head1 AUTHOR |
510 | |
601 | |
511 | Marc Lehmann <schmorp@schmorp.de> |
602 | Marc Lehmann <schmorp@schmorp.de> |
512 | http://software.schmorp.de/pkg/Convert-BER-XS |
603 | http://software.schmorp.de/pkg/Convert-BER-XS |