| … | |
… | |
| 8 | |
8 | |
| 9 | my $ber = ber_decode $buf, $Convert::BER::XS::SNMP_PROFILE |
9 | my $ber = ber_decode $buf, $Convert::BER::XS::SNMP_PROFILE |
| 10 | or die "unable to decode SNMP message"; |
10 | or die "unable to decode SNMP message"; |
| 11 | |
11 | |
| 12 | # The above results in a data structure consisting of |
12 | # The above results in a data structure consisting of |
| 13 | # (class, tag, flags, data) |
13 | # (class, tag, flags, data) |
| 14 | # tuples. Below is such a message, SNMPv1 trap |
14 | # tuples. Below is such a message, SNMPv1 trap |
| 15 | # with a Cisco mac change notification. |
15 | # with a Cisco mac change notification. |
| 16 | # Did you know that Cisco is in the news almost |
16 | # Did you know that Cisco is in the news almost |
| 17 | # every week because of some backdoor password |
17 | # every week because of some backdoor password |
| 18 | # or other extremely stupid security bug? |
18 | # or other extremely stupid security bug? |
| … | |
… | |
| 108 | BER_CLASS BER_TAG BER_FLAGS BER_DATA |
108 | BER_CLASS BER_TAG BER_FLAGS BER_DATA |
| 109 | |
109 | |
| 110 | =item C<:const_asn> |
110 | =item C<:const_asn> |
| 111 | |
111 | |
| 112 | ASN class values (these are C<0>, C<1>, C<2> and C<3>, respectively - |
112 | ASN class values (these are C<0>, C<1>, C<2> and C<3>, respectively - |
| 113 | exactly thw two topmost bits from the identifier octet shifted 6 bits to |
113 | exactly the two topmost bits from the identifier octet shifted 6 bits to |
| 114 | the right): |
114 | the right): |
| 115 | |
115 | |
| 116 | ASN_UNIVERSAL ASN_APPLICATION ASN_CONTEXT ASN_PRIVATE |
116 | ASN_UNIVERSAL ASN_APPLICATION ASN_CONTEXT ASN_PRIVATE |
| 117 | |
117 | |
| 118 | ASN tag values (some of which are aliases, such as C<ASN_OID>). Their |
118 | ASN tag values (some of which are aliases, such as C<ASN_OID>). Their |
| … | |
… | |
| 296 | Also, since BER is self-delimited, this can be used to decode multiple BER |
296 | Also, since BER is self-delimited, this can be used to decode multiple BER |
| 297 | values joined together. |
297 | values joined together. |
| 298 | |
298 | |
| 299 | =item $bindata = ber_encode $tuple[, $profile] |
299 | =item $bindata = ber_encode $tuple[, $profile] |
| 300 | |
300 | |
| 301 | Encodes the BER tuple into a BER/DER data structure. AS with |
301 | Encodes the BER tuple into a BER/DER data structure. As with |
| 302 | Cyber_decode>, an optional profile can be given. |
302 | Cyber_decode>, an optional profile can be given. |
| 303 | |
303 | |
| 304 | The encoded data should be both BER and DER ("shortest form") compliant |
304 | The encoded data should be both BER and DER ("shortest form") compliant |
| 305 | unless the input says otherwise (e.g. it uses constructed strings). |
305 | unless the input says otherwise (e.g. it uses constructed strings). |
| 306 | |
306 | |
| … | |
… | |
| 409 | use common::sense; |
409 | use common::sense; |
| 410 | |
410 | |
| 411 | use XSLoader (); |
411 | use XSLoader (); |
| 412 | use Exporter qw(import); |
412 | use Exporter qw(import); |
| 413 | |
413 | |
|
|
414 | use Carp (); |
|
|
415 | |
| 414 | our $VERSION; |
416 | our $VERSION; |
| 415 | |
417 | |
| 416 | BEGIN { |
418 | BEGIN { |
| 417 | $VERSION = '1.0'; |
419 | $VERSION = 1.21; |
| 418 | XSLoader::load __PACKAGE__, $VERSION; |
420 | XSLoader::load __PACKAGE__, $VERSION; |
| 419 | } |
421 | } |
| 420 | |
422 | |
| 421 | our %EXPORT_TAGS = ( |
423 | our %EXPORT_TAGS = ( |
| 422 | const_index => [qw( |
424 | const_index => [qw( |
| … | |
… | |
| 468 | |
470 | |
| 469 | $SNMP_PROFILE->set (ASN_APPLICATION, SNMP_IPADDRESS , BER_TYPE_IPADDRESS); |
471 | $SNMP_PROFILE->set (ASN_APPLICATION, SNMP_IPADDRESS , BER_TYPE_IPADDRESS); |
| 470 | $SNMP_PROFILE->set (ASN_APPLICATION, SNMP_COUNTER32 , BER_TYPE_INT); |
472 | $SNMP_PROFILE->set (ASN_APPLICATION, SNMP_COUNTER32 , BER_TYPE_INT); |
| 471 | $SNMP_PROFILE->set (ASN_APPLICATION, SNMP_UNSIGNED32, BER_TYPE_INT); |
473 | $SNMP_PROFILE->set (ASN_APPLICATION, SNMP_UNSIGNED32, BER_TYPE_INT); |
| 472 | $SNMP_PROFILE->set (ASN_APPLICATION, SNMP_TIMETICKS , BER_TYPE_INT); |
474 | $SNMP_PROFILE->set (ASN_APPLICATION, SNMP_TIMETICKS , BER_TYPE_INT); |
| 473 | $SNMP_PROFILE->set (ASN_APPLICATION, SNMP_OPAQUE , BER_TYPE_IPADDRESS); |
475 | |
|
|
476 | # decodes REAL values according to ECMA-63 |
|
|
477 | # this is pretty strict, except it doesn't catch -0. |
|
|
478 | # I don't have access to ISO 6093 (or BS 6727, or ANSI X.3-42)), so this is all guesswork. |
|
|
479 | sub _decode_real_decimal { |
|
|
480 | my ($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 | } |
| 474 | |
518 | |
| 475 | =head2 DEBUGGING |
519 | =head2 DEBUGGING |
| 476 | |
520 | |
| 477 | To aid debugging, you cna call the C<ber_dump> function to print a "nice" |
521 | To aid debugging, you can call the C<ber_dump> function to print a "nice" |
| 478 | representation to STDOUT. |
522 | representation to STDOUT. |
| 479 | |
523 | |
| 480 | =over |
524 | =over |
| 481 | |
525 | |
| 482 | =item ber_dump $tuple[, $profile[, $prefix]] |
526 | =item ber_dump $tuple[, $profile[, $prefix]] |
| 483 | |
527 | |
| 484 | In addition to specifying the BER C<$tuple> to dump, youc an also specify |
528 | In addition to specifying the BER C<$tuple> to dump, you can also specify |
| 485 | a C<$profile> and a C<$prefix> string that is printed in front of each line. |
529 | a C<$profile> and a C<$prefix> string that is printed in front of each line. |
| 486 | |
530 | |
| 487 | If C<$profile> is C<$Convert::BER::XS::SNMP_PROFILE>, then C<ber_dump> |
531 | If C<$profile> is C<$Convert::BER::XS::SNMP_PROFILE>, then C<ber_dump> |
| 488 | will try to improve its output for SNMP data. |
532 | will try to improve its output for SNMP data. |
| 489 | |
533 | |
| … | |
… | |
| 496 | Example output: |
540 | Example output: |
| 497 | |
541 | |
| 498 | SEQUENCE |
542 | SEQUENCE |
| 499 | | OCTET_STRING bytes 800063784300454045045400000001 |
543 | | OCTET_STRING bytes 800063784300454045045400000001 |
| 500 | | OCTET_STRING bytes |
544 | | OCTET_STRING bytes |
| 501 | | CONTEXT (7) bytes CONSTRUCTED |
545 | | CONTEXT (7) CONSTRUCTED |
| 502 | | | INTEGER int 1058588941 |
546 | | | INTEGER int 1058588941 |
| 503 | | | INTEGER int 0 |
547 | | | INTEGER int 0 |
| 504 | | | INTEGER int 0 |
548 | | | INTEGER int 0 |
| 505 | | | SEQUENCE |
549 | | | SEQUENCE |
| 506 | | | | SEQUENCE |
550 | | | | SEQUENCE |
| … | |
… | |
| 549 | $class =~ s/^ASN_//; |
593 | $class =~ s/^ASN_//; |
| 550 | $tag =~ s/^(ASN_|SNMP_)//; |
594 | $tag =~ s/^(ASN_|SNMP_)//; |
| 551 | $type =~ s/^BER_TYPE_//; |
595 | $type =~ s/^BER_TYPE_//; |
| 552 | |
596 | |
| 553 | if ($ber->[BER_FLAGS]) { |
597 | if ($ber->[BER_FLAGS]) { |
| 554 | printf "$indent%-16.16s %-6.6s CONSTRUCTED\n", $tag, lc $type; |
598 | printf "$indent%-16.16s\n", $tag; |
| 555 | &_ber_dump ($_, $profile, "$indent| ") |
599 | &_ber_dump ($_, $profile, "$indent| ") |
| 556 | for @$data; |
600 | for @$data; |
| 557 | } else { |
601 | } else { |
| 558 | if ($data =~ y/\x20-\x7e//c / (length $data || 1) > 0.2 or $data =~ /\x00./s) { |
602 | if ($data =~ y/\x20-\x7e//c / (length $data || 1) > 0.2 or $data =~ /\x00./s) { |
| 559 | # assume binary |
603 | # assume binary |
| 560 | $data = unpack "H*", $data; |
604 | $data = unpack "H*", $data; |
| 561 | } else { |
605 | } else { |
| 562 | $data =~ s/[^\x20-\x7e]/./g; |
606 | $data =~ s/[^\x20-\x7e]/./g; |
| 563 | $data = "\"$data\"" if $type =~ /string/i || !length $data; |
607 | $data = "\"$data\"" if $tag =~ /string/i || !length $data; |
| 564 | } |
608 | } |
| 565 | |
609 | |
| 566 | substr $data, 40, 1e9, "..." if 40 < length $data; |
610 | substr $data, 40, 1e9, "..." if 40 < length $data; |
| 567 | |
611 | |
| 568 | printf "$indent%-16.16s %-6.6s %s\n", $tag, lc $type, $data; |
612 | printf "$indent%-16.16s %-6.6s %s\n", $tag, lc $type, $data; |
| … | |
… | |
| 641 | |
685 | |
| 642 | Returns the BER type mapped to the given C<$class>/C<$tag> combination. |
686 | Returns the BER type mapped to the given C<$class>/C<$tag> combination. |
| 643 | |
687 | |
| 644 | =back |
688 | =back |
| 645 | |
689 | |
| 646 | =head2 BER TYPES |
690 | =head2 BER Types |
| 647 | |
691 | |
| 648 | This lists the predefined BER types - you can map any C<CLASS>/C<TAG> |
692 | This lists the predefined BER types. BER types are formatters used |
| 649 | combination to any C<BER_TYPE_*>. |
693 | internally to format and encode BER values. You can assign any C<BER_TYPE> |
|
|
694 | to any C<CLASS>/C<TAG> combination tgo change how that tag is decoded or |
|
|
695 | encoded. |
| 650 | |
696 | |
| 651 | =over |
697 | =over |
| 652 | |
698 | |
| 653 | =item C<BER_TYPE_BYTES> |
699 | =item C<BER_TYPE_BYTES> |
| 654 | |
700 | |
| … | |
… | |
| 731 | |
777 | |
| 732 | $SNMP_PROFILE->set (ASN_APPLICATION, SNMP_IPADDRESS , BER_TYPE_IPADDRESS); |
778 | $SNMP_PROFILE->set (ASN_APPLICATION, SNMP_IPADDRESS , BER_TYPE_IPADDRESS); |
| 733 | $SNMP_PROFILE->set (ASN_APPLICATION, SNMP_COUNTER32 , BER_TYPE_INT); |
779 | $SNMP_PROFILE->set (ASN_APPLICATION, SNMP_COUNTER32 , BER_TYPE_INT); |
| 734 | $SNMP_PROFILE->set (ASN_APPLICATION, SNMP_UNSIGNED32, BER_TYPE_INT); |
780 | $SNMP_PROFILE->set (ASN_APPLICATION, SNMP_UNSIGNED32, BER_TYPE_INT); |
| 735 | $SNMP_PROFILE->set (ASN_APPLICATION, SNMP_TIMETICKS , BER_TYPE_INT); |
781 | $SNMP_PROFILE->set (ASN_APPLICATION, SNMP_TIMETICKS , BER_TYPE_INT); |
| 736 | $SNMP_PROFILE->set (ASN_APPLICATION, SNMP_OPAQUE , BER_TYPE_IPADDRESS); |
782 | $SNMP_PROFILE->set (ASN_APPLICATION, SNMP_OPAQUE , BER_TYPE_BYTES); |
| 737 | $SNMP_PROFILE->set (ASN_APPLICATION, SNMP_COUNTER64 , BER_TYPE_INT); |
783 | $SNMP_PROFILE->set (ASN_APPLICATION, SNMP_COUNTER64 , BER_TYPE_INT); |
| 738 | |
784 | |
| 739 | =head2 LIMITATIONS/NOTES |
785 | =head2 LIMITATIONS/NOTES |
| 740 | |
786 | |
| 741 | This module can only en-/decode 64 bit signed and unsigned integers, and |
787 | This module can only en-/decode 64 bit signed and unsigned |
| 742 | only when your perl supports those. So no UUID OIDs for now. |
788 | integers/tags/lengths, and only when your perl supports those. So no UUID |
|
|
789 | OIDs for now (unless you map the C<OBJECT IDENTIFIER> tag to something |
|
|
790 | other than C<BER_TYPE_OID>). |
| 743 | |
791 | |
| 744 | This module does not generally care about ranges, i.e. it will happily |
792 | This module does not generally care about ranges, i.e. it will happily |
| 745 | de-/encode 64 bit integers into an C<ASN_INTEGER> value, or a negative |
793 | de-/encode 64 bit integers into an C<SNMP_UNSIGNED32> value, or a negative |
| 746 | number into an C<SNMP_COUNTER64>. |
794 | number into an C<SNMP_COUNTER64>. |
| 747 | |
795 | |
| 748 | OBJECT IDENTIFIEERs cannot have unlimited length, although the limit is |
796 | OBJECT IDENTIFIEERs cannot have unlimited length, although the limit is |
| 749 | much larger than e.g. the one imposed by SNMP or other protocols,a nd is |
797 | much larger than e.g. the one imposed by SNMP or other protocols, and is |
| 750 | about 4kB. |
798 | about 4kB. |
| 751 | |
|
|
| 752 | Indefinite length encoding is not supported. |
|
|
| 753 | |
799 | |
| 754 | Constructed strings are decoded just fine, but there should be a way to |
800 | Constructed strings are decoded just fine, but there should be a way to |
| 755 | join them for convenience. |
801 | join them for convenience. |
| 756 | |
802 | |
| 757 | REAL values are not supported and will currently croak. |
803 | REAL values will always be encoded in decimal form and ssometimes is |
| 758 | |
804 | forced into a perl "NV" type, potentially losing precision. |
| 759 | The encoder and decoder tend to accept more formats than should be |
|
|
| 760 | strictly supported. |
|
|
| 761 | |
|
|
| 762 | This module has undergone little to no testing so far. |
|
|
| 763 | |
805 | |
| 764 | =head2 ITHREADS SUPPORT |
806 | =head2 ITHREADS SUPPORT |
| 765 | |
807 | |
| 766 | This module is unlikely to work when the (officially discouraged) ithreads |
808 | This module is unlikely to work in any other than the loading thread when |
| 767 | are in use. |
809 | the (officially discouraged) ithreads are in use. |
| 768 | |
810 | |
| 769 | =head1 AUTHOR |
811 | =head1 AUTHOR |
| 770 | |
812 | |
| 771 | Marc Lehmann <schmorp@schmorp.de> |
813 | Marc Lehmann <schmorp@schmorp.de> |
| 772 | http://software.schmorp.de/pkg/Convert-BER-XS |
814 | http://software.schmorp.de/pkg/Convert-BER-XS |
