| 1 |
=head1 NAME |
| 2 |
|
| 3 |
Convert::BER::XS - I<very> low level BER en-/decoding |
| 4 |
|
| 5 |
=head1 SYNOPSIS |
| 6 |
|
| 7 |
use Convert::BER::XS ':all'; |
| 8 |
|
| 9 |
my $ber = ber_decode $buf |
| 10 |
or die "unable to decode SNMP message"; |
| 11 |
|
| 12 |
# The above results in a data structure consisting of |
| 13 |
# (class, tag, # constructed, data) |
| 14 |
# tuples. Below is such a message, SNMPv1 trap |
| 15 |
# with a Cisco mac change notification. |
| 16 |
# Did you know that Cisco is in the news almost |
| 17 |
# every week because # of some backdoor password |
| 18 |
# or other extremely stupid security bug? |
| 19 |
|
| 20 |
[ ASN_UNIVERSAL, ASN_SEQUENCE, 1, |
| 21 |
[ |
| 22 |
[ ASN_UNIVERSAL, ASN_INTEGER32, 0, 0 ], # snmp version 1 |
| 23 |
[ ASN_UNIVERSAL, 4, 0, "public" ], # community |
| 24 |
[ ASN_CONTEXT, 4, 1, # CHOICE, constructed - trap PDU |
| 25 |
[ |
| 26 |
[ ASN_UNIVERSAL, ASN_OBJECT_IDENTIFIER, 0, "1.3.6.1.4.1.9.9.215.2" ], # enterprise oid |
| 27 |
[ ASN_APPLICATION, 0, 0, "\x0a\x00\x00\x01" ], # SNMP IpAddress, 10.0.0.1 |
| 28 |
[ ASN_UNIVERSAL, ASN_INTEGER32, 0, 6 ], # generic trap |
| 29 |
[ ASN_UNIVERSAL, ASN_INTEGER32, 0, 1 ], # specific trap |
| 30 |
[ ASN_APPLICATION, ASN_TIMETICKS, 0, 1817903850 ], # SNMP TimeTicks |
| 31 |
[ ASN_UNIVERSAL, ASN_SEQUENCE, 1, # the varbindlist |
| 32 |
[ |
| 33 |
[ ASN_UNIVERSAL, ASN_SEQUENCE, 1, # a single varbind, "key value" pair |
| 34 |
[ |
| 35 |
[ ASN_UNIVERSAL, ASN_OBJECT_IDENTIFIER, 0, "1.3.6.1.4.1.9.9.215.1.1.8.1.2.1" ], |
| 36 |
[ ASN_UNIVERSAL, ASN_OCTET_STRING, 0, "...data..." # the value |
| 37 |
] |
| 38 |
] |
| 39 |
], |
| 40 |
... |
| 41 |
|
| 42 |
# let's decode it a bit with some helper functions |
| 43 |
|
| 44 |
my $msg = ber_is_seq $ber |
| 45 |
or die "SNMP message does not start with a sequence"; |
| 46 |
|
| 47 |
ber_is $msg->[0], ASN_UNIVERSAL, ASN_INTEGER32, 0 |
| 48 |
or die "SNMP message does not start with snmp version\n"; |
| 49 |
|
| 50 |
# message is SNMP v1 or v2c? |
| 51 |
if ($msg->[0][BER_DATA] == 0 || $msg->[0][BER_DATA] == 1) { |
| 52 |
|
| 53 |
# message is v1 trap? |
| 54 |
if (ber_is $msg->[2], ASN_CONTEXT, 4, 1) { |
| 55 |
my $trap = $msg->[2][BER_DATA]; |
| 56 |
|
| 57 |
# check whether trap is a cisco mac notification mac changed message |
| 58 |
if ( |
| 59 |
(ber_is_oid $trap->[0], "1.3.6.1.4.1.9.9.215.2") # cmnInterfaceObjects |
| 60 |
and (ber_is_i32 $trap->[2], 6) |
| 61 |
and (ber_is_i32 $trap->[3], 1) # mac changed msg |
| 62 |
) { |
| 63 |
... and so on |
| 64 |
|
| 65 |
# finally, let's encode it again and hope it results in the same bit pattern |
| 66 |
|
| 67 |
my $buf = ber_encode $ber; |
| 68 |
|
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=head1 DESCRIPTION |
| 70 |
|
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WARNING: Before release 1.0, the API is not considered stable in any way. |
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|
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This module implements a I<very> low level BER/DER en-/decoder. |
| 74 |
|
| 75 |
If is tuned for low memory and high speed, while still maintaining some |
| 76 |
level of user-friendlyness. |
| 77 |
|
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Currently, not much is documented, as this is an initial release to |
| 79 |
reserve CPAN namespace, stay tuned for a few days. |
| 80 |
|
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=head2 ASN.1/BER/DER/... BASICS |
| 82 |
|
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ASN.1 is a strange language that can be sed to describe protocols and |
| 84 |
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 |
| 86 |
of this module, and is used in SNMP or LDAP for example. |
| 87 |
|
| 88 |
While ASN.1 defines a schema that is useful to interpret encoded data, |
| 89 |
the BER encoding is actually somewhat self-describing: you might not know |
| 90 |
whether something is a string or a number or a sequence or something else, |
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but you can nevertheless decode the overall structure, even if you end up |
| 92 |
with just a binary blob for the actual value. |
| 93 |
|
| 94 |
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 |
| 96 |
"constructed") or not (is "primitive"). |
| 97 |
|
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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 |
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string types, but there is no unsigned32 type for example. Different |
| 101 |
applications work around this in different ways, for example, SNMP defines |
| 102 |
application-specific Gauge32, Counter32 and Unsigned32, which are mapped |
| 103 |
to two different tags: you can distinguish between Counter32 and the |
| 104 |
others, but not between Gause32 and Unsigned32, without the ASN.1 schema. |
| 105 |
|
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Ugh. |
| 107 |
|
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=head2 DECODED BER REPRESENTATION |
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|
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This module represents every BER value as a 4-element tuple (actually an |
| 111 |
array-reference): |
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|
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[CLASS, TAG, CONSTRUCTED, DATA] |
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|
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To avoid non-descriptive hardcoded array index numbers, this module |
| 116 |
defines symbolic constants to access these members: C<BER_CLASS>, |
| 117 |
C<BER_TAG>, C<BER_CONSTRUCTED> and C<BER_DATA>. |
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|
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Also, the first three members are integers with a little caveat: for |
| 120 |
performance reasons, these are readonly and shared, so you must not modify |
| 121 |
them (increment, assign to them etc.) in any way. You may modify the |
| 122 |
I<DATA> member, and you may re-assign the array itself, e.g.: |
| 123 |
|
| 124 |
$ber = ber_decode $binbuf; |
| 125 |
|
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# the following is NOT legal: |
| 127 |
$ber->[BER_CLASS] = ASN_PRIVATE; # ERROR, CLASS/TAG/CONSTRUCTED are READ ONLY(!) |
| 128 |
|
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# but all of the following are fine: |
| 130 |
$ber->[BER_DATA] = "string"; |
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$ber->[BER_DATA] = [ASN_UNIVERSAL, ASN_INTEGER32, 0, 123]; |
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@$ber = (ASN_APPLICATION, SNMP_TIMETICKS, 0, 1000); |
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|
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I<CLASS> is something like a namespace for I<TAG>s - there is the |
| 135 |
C<ASN_UNIVERSAL> namespace which defines tags common to all ASN.1 |
| 136 |
implementations, the C<ASN_APPLICATION> namespace which defines tags for |
| 137 |
specific applications (for example, the SNMP C<Unsigned32> type is in this |
| 138 |
namespace), a special-purpose context namespace (C<ASN_CONTEXT>, used e.g. |
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for C<CHOICE>) and a private namespace (C<ASN_PRIVATE>). |
| 140 |
|
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The meaning of the I<TAG> depends on the namespace, and defines a |
| 142 |
(partial) interpretation of the data value. For example, right now, SNMP |
| 143 |
application namespace knowledge ix hardcoded into this module, so it |
| 144 |
knows that SNMP C<Unsigned32> values need to be decoded into actual perl |
| 145 |
integers. |
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|
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The most common tags in the C<ASN_UNIVERSAL> namespace are |
| 148 |
C<ASN_INTEGER32>, C<ASN_BIT_STRING>, C<ASN_NULL>, C<ASN_OCTET_STRING>, |
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C<ASN_OBJECT_IDENTIFIER>, C<ASN_SEQUENCE>, C<ASN_SET> and |
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C<ASN_IA5_STRING>. |
| 151 |
|
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The most common tags in SNMP's C<ASN_APPLICATION> namespace |
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are C<SNMP_IPADDRESS>, C<SNMP_COUNTER32>, C<SNMP_UNSIGNED32>, |
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C<SNMP_TIMETICKS>, C<SNMP_OPAQUE> and C<SNMP_COUNTER64>. |
| 155 |
|
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The I<CONSTRUCTED> flag is really just a boolean - if it is false, the |
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the value is "primitive" and contains no subvalues, kind of like a |
| 158 |
non-reference perl scalar. IF it is true, then the value is "constructed" |
| 159 |
which just means it contains a list of subvalues which this module will |
| 160 |
en-/decode as BER tuples themselves. |
| 161 |
|
| 162 |
The I<DATA> value is either a reference to an array of further tuples (if |
| 163 |
the value is I<CONSTRUCTED>), some decoded representation of the value, |
| 164 |
if this module knows how to decode it (e.g. for the integer types above) |
| 165 |
or a binary string with the raw octets if this module doesn't know how to |
| 166 |
interpret the namespace/tag. |
| 167 |
|
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Thus, you can always decode a BER data structure and at worst you get a |
| 169 |
string in place of some nice decoded value. |
| 170 |
|
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See the SYNOPSIS for an example of such an encoded tuple representation. |
| 172 |
|
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=head2 DECODING AND ENCODING |
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|
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=over |
| 176 |
|
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=item $tuple = ber_decoded $bindata |
| 178 |
|
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Decodes binary BER data in C<$bindata> and returns the resulting BER |
| 180 |
tuple. Croaks on any decoding error, so the returned C<$tuple> is always |
| 181 |
valid. |
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|
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=item $bindata = ber_encode $tuple |
| 184 |
|
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Encodes the BER tuple into a BER/DER data structure. |
| 186 |
|
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=back |
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|
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=head2 HELPER FUNCTIONS |
| 190 |
|
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Working with a 4-tuple for every value can be annoying. Or, rather, I<is> |
| 192 |
annoying. To reduce this a bit, this module defines a number of helper |
| 193 |
functions, both to match BER tuples and to conmstruct BER tuples: |
| 194 |
|
| 195 |
=head3 MATCH HELPERS |
| 196 |
|
| 197 |
Thse functions accept a BER tuple as first argument and either paertially |
| 198 |
or fully match it. They often come in two forms, one which exactly matches |
| 199 |
a value, and one which only matches the type and returns the value. |
| 200 |
|
| 201 |
They do check whether valid tuples are passed in and croak otherwise. As |
| 202 |
a ease-of-use exception, they usually also accept C<undef> instead of a |
| 203 |
tuple reference. in which case they silently fail to match. |
| 204 |
|
| 205 |
=over |
| 206 |
|
| 207 |
=item $bool = ber_is $tuple, $class, $tag, $constructed, $data |
| 208 |
|
| 209 |
This takes a BER C<$tuple> and matches its elements agains the privded |
| 210 |
values, all of which are optional - values that are either missing or |
| 211 |
C<undef> will be ignored, the others will be matched exactly (e.g. as if |
| 212 |
you used C<==> or C<eq> (for C<$data>)). |
| 213 |
|
| 214 |
Some examples: |
| 215 |
|
| 216 |
ber_is $tuple, ASN_UNIVERSAL, ASN_SEQUENCE, 1 |
| 217 |
orf die "tuple is not an ASN SEQUENCE"; |
| 218 |
|
| 219 |
ber_is $tuple, ASN_UNIVERSAL, ASN_NULL |
| 220 |
or die "tuple is not an ASN NULL value"; |
| 221 |
|
| 222 |
ber_is $tuple, ASN_UNIVERSAL, ASN_INTEGER32, 0, 50 |
| 223 |
or die "BER integer must be 50"; |
| 224 |
|
| 225 |
=item $seq = ber_is_seq $tuple |
| 226 |
|
| 227 |
Returns the sequence members (the array of subvalues) if the C<$tuple> is |
| 228 |
an ASN SEQUENCE, i.e. the C<BER_DATA> member. If the C<$tuple> is not a |
| 229 |
sequence it returns C<undef>. For example, SNMP version 1/2c/3 packets all |
| 230 |
consist of an outer SEQUENCE value: |
| 231 |
|
| 232 |
my $ber = ber_decode $snmp_data; |
| 233 |
|
| 234 |
my $snmp = ber_is_seq $ber |
| 235 |
or die "SNMP packet invalid: does not start with SEQUENCE"; |
| 236 |
|
| 237 |
# now we know $snmp is a sequence, so decode the SNMP version |
| 238 |
|
| 239 |
my $version = ber_is_i32 $snmp->[0] |
| 240 |
or die "SNMP packet invalid: does not start with version number"; |
| 241 |
|
| 242 |
=item $bool = ber_is_i32 $tuple, $i32 |
| 243 |
|
| 244 |
Returns a true value if the C<$tuple> represents an ASN INTEGER32 with |
| 245 |
the value C<$i32>. |
| 246 |
|
| 247 |
=item $i32 = ber_is_i32 $tuple |
| 248 |
|
| 249 |
Returns true (and extracts the integer value) if the C<$tuple> is an ASN |
| 250 |
INTEGER32. For C<0>, this function returns a special value that is 0 but |
| 251 |
true. |
| 252 |
|
| 253 |
=item $bool = ber_is_oid $tuple, $oid_string |
| 254 |
|
| 255 |
Returns true if the C<$tuple> represents an ASN_OBJECT_IDENTIFIER |
| 256 |
that exactly matches C<$oid_string>. Example: |
| 257 |
|
| 258 |
ber_is_oid $tuple, "1.3.6.1.4" |
| 259 |
or die "oid must be 1.3.6.1.4"; |
| 260 |
|
| 261 |
=item $oid = ber_is_oid $tuple |
| 262 |
|
| 263 |
Returns true (and extracts the OID string) if the C<$tuple> is an ASN |
| 264 |
OBJECT IDENTIFIER. Otherwise, it returns C<undef>. |
| 265 |
|
| 266 |
=back |
| 267 |
|
| 268 |
=head3 CONSTRUCTION HELPERS |
| 269 |
|
| 270 |
=over |
| 271 |
|
| 272 |
=item $tuple = ber_i32 $value |
| 273 |
|
| 274 |
Constructs a new C<ASN_INTEGER32> tuple. |
| 275 |
|
| 276 |
=back |
| 277 |
|
| 278 |
=head2 RELATIONSHIP TO L<Convert::BER> and L<Convert::ASN1> |
| 279 |
|
| 280 |
This module is I<not> the XS version of L<Convert::BER>, but a different |
| 281 |
take at doing the same thing. I imagine this module would be a good base |
| 282 |
for speeding up either of these, or write a similar module, or write your |
| 283 |
own LDAP or SNMP module for example. |
| 284 |
|
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=cut |
| 286 |
|
| 287 |
package Convert::BER::XS; |
| 288 |
|
| 289 |
use common::sense; |
| 290 |
|
| 291 |
use XSLoader (); |
| 292 |
use Exporter qw(import); |
| 293 |
|
| 294 |
our $VERSION; |
| 295 |
|
| 296 |
BEGIN { |
| 297 |
$VERSION = 0.7; |
| 298 |
XSLoader::load __PACKAGE__, $VERSION; |
| 299 |
} |
| 300 |
|
| 301 |
our %EXPORT_TAGS = ( |
| 302 |
const => [qw( |
| 303 |
BER_CLASS BER_TAG BER_CONSTRUCTED BER_DATA |
| 304 |
|
| 305 |
ASN_BOOLEAN ASN_INTEGER32 ASN_BIT_STRING ASN_OCTET_STRING ASN_NULL ASN_OBJECT_IDENTIFIER |
| 306 |
ASN_OBJECT_DESCRIPTOR ASN_OID ASN_EXTERNAL ASN_REAL ASN_SEQUENCE ASN_ENUMERATED |
| 307 |
ASN_EMBEDDED_PDV ASN_UTF8_STRING ASN_RELATIVE_OID ASN_SET ASN_NUMERIC_STRING |
| 308 |
ASN_PRINTABLE_STRING ASN_TELETEX_STRING ASN_T61_STRING ASN_VIDEOTEX_STRING ASN_IA5_STRING |
| 309 |
ASN_ASCII_STRING ASN_UTC_TIME ASN_GENERALIZED_TIME ASN_GRAPHIC_STRING ASN_VISIBLE_STRING |
| 310 |
ASN_ISO646_STRING ASN_GENERAL_STRING ASN_UNIVERSAL_STRING ASN_CHARACTER_STRING ASN_BMP_STRING |
| 311 |
|
| 312 |
ASN_UNIVERSAL ASN_APPLICATION ASN_CONTEXT ASN_PRIVATE |
| 313 |
|
| 314 |
BER_TYPE_BYTES BER_TYPE_UTF8 BER_TYPE_UCS2 BER_TYPE_UCS4 BER_TYPE_INT |
| 315 |
BER_TYPE_OID BER_TYPE_RELOID BER_TYPE_NULL BER_TYPE_BOOL BER_TYPE_REAL |
| 316 |
BER_TYPE_IPADDRESS BER_TYPE_CROAK |
| 317 |
)], |
| 318 |
const_snmp => [qw( |
| 319 |
SNMP_IPADDRESS SNMP_COUNTER32 SNMP_UNSIGNED32 SNMP_TIMETICKS SNMP_OPAQUE SNMP_COUNTER64 |
| 320 |
)], |
| 321 |
encode => [qw( |
| 322 |
ber_decode |
| 323 |
ber_is ber_is_seq ber_is_i32 ber_is_oid |
| 324 |
)], |
| 325 |
decode => [qw( |
| 326 |
ber_encode |
| 327 |
ber_i32 |
| 328 |
)], |
| 329 |
); |
| 330 |
|
| 331 |
our @EXPORT_OK = map @$_, values %EXPORT_TAGS; |
| 332 |
|
| 333 |
$EXPORT_TAGS{all} = \@EXPORT_OK; |
| 334 |
|
| 335 |
=head1 PROFILES |
| 336 |
|
| 337 |
While any BER data can be correctly encoded and decoded out of the box, it |
| 338 |
can be inconvenient to have to manually decode some values into a "better" |
| 339 |
format: for instance, SNMP TimeTicks values are decoded into the raw octet |
| 340 |
strings of their BER representation, which is quite hard to decode. With |
| 341 |
profiles, you can change which class/tag combinations map to which decoder |
| 342 |
function inside C<ber_decode> (and of course also which encoder functions |
| 343 |
are used in C<ber_encode>). |
| 344 |
|
| 345 |
This works by mapping specific class/tag combinations to an internal "ber |
| 346 |
type". |
| 347 |
|
| 348 |
The default profile supports the standard ASN.1 types, but no |
| 349 |
application-specific ones. This means that class/tag combinations not in |
| 350 |
the base set of ASN.1 are decoded into their raw octet strings. |
| 351 |
|
| 352 |
C<Convert::BER::XS> defines two profile variables you cna use out of the box: |
| 353 |
|
| 354 |
=over |
| 355 |
|
| 356 |
=item C<$Convert::BER::XS::DEFAULT_PROFILE> |
| 357 |
|
| 358 |
This is the default profile, i.e. the profile that is used when no |
| 359 |
profile is specified for de-/encoding. |
| 360 |
|
| 361 |
You cna modify it, but remember that this modifies the defaults for all |
| 362 |
callers that rely on the defauit profile. |
| 363 |
|
| 364 |
=item C<$Convert::BER::XS::SNMP_PROFILE> |
| 365 |
|
| 366 |
A profile with mappings for SNMP-specific application tags added. This is |
| 367 |
useful when de-/encoding SNMP data. |
| 368 |
|
| 369 |
Example: |
| 370 |
$ber = ber_decode $data, $Convert::BER::XS::SNMP_PROFILE; |
| 371 |
|
| 372 |
=back |
| 373 |
|
| 374 |
=head2 The Convert::BER::XS::Profile class |
| 375 |
|
| 376 |
=over |
| 377 |
|
| 378 |
=item $profile = new Convert::BER::XS::Profile |
| 379 |
|
| 380 |
Create a new profile. The profile will be identical to the default |
| 381 |
profile. |
| 382 |
|
| 383 |
=item $profile->set ($class, $tag, $type) |
| 384 |
|
| 385 |
Sets the mapping for the given C<$class>/C<$tag> combination to C<$type>, |
| 386 |
which must be one of the C<BER_TYPE_*> constants. |
| 387 |
|
| 388 |
Note that currently, the mapping is stored in a flat array, so large |
| 389 |
values of C<$tag> will consume large amounts of memory. |
| 390 |
|
| 391 |
Example: |
| 392 |
$profile = new Convert::BER::XS::Profile; |
| 393 |
$profile->set (ASN_APPLICATION, SNMP_COUNTER32, BER_TYPE_INT); |
| 394 |
$ber = ber_decode $data, $profile; |
| 395 |
|
| 396 |
=item $type = $profile->get ($class, $tag) |
| 397 |
|
| 398 |
Returns the BER type mapped to the given C<$class>/C<$tag> combination. |
| 399 |
|
| 400 |
=back |
| 401 |
|
| 402 |
=head2 BER TYPES |
| 403 |
|
| 404 |
This lists the predefined BER types - you can map any C<CLASS>/C<TAG> |
| 405 |
combination to any C<BER_TYPE_*>. |
| 406 |
|
| 407 |
=over |
| 408 |
|
| 409 |
=item C<BER_TYPE_BYTES> |
| 410 |
|
| 411 |
The raw octets of the value. This is the default type for unknown tags and |
| 412 |
de-/encodes the value as if it were an octet string, i.e. by copying the |
| 413 |
raw bytes. |
| 414 |
|
| 415 |
=item C<BER_TYPE_UTF8> |
| 416 |
|
| 417 |
Like C<BER_TYPE_BYTES>, but decodes the value as if it were a UTF-8 string |
| 418 |
(without validation!) and encodes a perl unicode string into a UTF-8 BER |
| 419 |
string. |
| 420 |
|
| 421 |
=item C<BER_TYPE_UCS2> |
| 422 |
|
| 423 |
Similar to C<BER_TYPE_UTF8>, but treats the BER value as UCS-2 encoded |
| 424 |
string. NOT IMPLEMENTED. |
| 425 |
|
| 426 |
=item C<BER_TYPE_UCS4> |
| 427 |
|
| 428 |
Similar to C<BER_TYPE_UTF8>, but treats the BER value as UCS-4 encoded |
| 429 |
string. NOT IMPLEMENTED. |
| 430 |
|
| 431 |
=item C<BER_TYPE_INT> |
| 432 |
|
| 433 |
Encodes and decodes a BER integer value to a perl integer scalar. This |
| 434 |
should correctly handle 64 bit signed and unsigned values. |
| 435 |
|
| 436 |
=item C<BER_TYPE_OID> |
| 437 |
|
| 438 |
Encodes and decodes an OBJECT IDENTIFIER into dotted form without leading |
| 439 |
dot, e.g. C<1.3.6.1.213>. |
| 440 |
|
| 441 |
=item C<BER_TYPE_RELOID> |
| 442 |
|
| 443 |
Same as C<BER_TYPE_OID> but uses relative OID encoding: ASN.1 has this |
| 444 |
hack of encoding the first two OID components into a single integer in a |
| 445 |
weird attempt to save an insignificant amount of space in an otherwise |
| 446 |
wasteful encoding, and relative OIDs are basically OIDs without this |
| 447 |
hack. The practical difference is that the second component of an OID |
| 448 |
can only have the values 1..40, while relative OIDs do not have this |
| 449 |
restriction. |
| 450 |
|
| 451 |
=item C<BER_TYPE_NULL> |
| 452 |
|
| 453 |
Decodes an C<ASN_NULL> value into C<undef>, and always encodes a |
| 454 |
C<ASN_NULL> type, regardless of the perl value. |
| 455 |
|
| 456 |
=item C<BER_TYPE_BOOL> |
| 457 |
|
| 458 |
Decodes an C<ASN_BOOLEAN> value into C<0> or C<1>, and encodes a perl |
| 459 |
boolean value into an C<ASN_BOOLEAN>. |
| 460 |
|
| 461 |
=item C<BER_TYPE_REAL> |
| 462 |
|
| 463 |
Decodes/encodes a BER real value. NOT IMPLEMENTED. |
| 464 |
|
| 465 |
=item C<BER_TYPE_IPADDRESS> |
| 466 |
|
| 467 |
Decodes/encodes a four byte string into an IOv4 dotted-quad address string |
| 468 |
in perl. Given ther obsolete nature of this type, this is a low-effort |
| 469 |
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>. |
| 471 |
|
| 472 |
=item C<BER_TYPE_CROAK> |
| 473 |
|
| 474 |
Always croaks when encountered during encoding or decoding - the |
| 475 |
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 |
| 477 |
error for some types, then CyBER_TYPE_CROAK> is for you. |
| 478 |
|
| 479 |
=back |
| 480 |
|
| 481 |
=cut |
| 482 |
|
| 483 |
our $DEFAULT_PROFILE = new Convert::BER::XS::Profile; |
| 484 |
our $SNMP_PROFILE = new Convert::BER::XS::Profile; |
| 485 |
|
| 486 |
$SNMP_PROFILE->set (ASN_APPLICATION, SNMP_IPADDRESS , BER_TYPE_IPADDRESS); |
| 487 |
$SNMP_PROFILE->set (ASN_APPLICATION, SNMP_COUNTER32 , BER_TYPE_INT); |
| 488 |
$SNMP_PROFILE->set (ASN_APPLICATION, SNMP_UNSIGNED32, BER_TYPE_INT); |
| 489 |
$SNMP_PROFILE->set (ASN_APPLICATION, SNMP_TIMETICKS , BER_TYPE_INT); |
| 490 |
$SNMP_PROFILE->set (ASN_APPLICATION, SNMP_OPAQUE , BER_TYPE_IPADDRESS); |
| 491 |
$SNMP_PROFILE->set (ASN_APPLICATION, SNMP_COUNTER64 , BER_TYPE_INT); |
| 492 |
|
| 493 |
$DEFAULT_PROFILE->_set_default; |
| 494 |
|
| 495 |
1; |
| 496 |
|
| 497 |
=head2 LIMITATIONS |
| 498 |
|
| 499 |
This module can only en-/decode 64 bit signed and unsigned integers, and |
| 500 |
only when your perl supports those. |
| 501 |
|
| 502 |
OBJECT IDENTIFIEERS cannot have unlimited length, although the limit is |
| 503 |
much larger than e.g. the one imposed by SNMP or other protocols. |
| 504 |
|
| 505 |
=head1 AUTHOR |
| 506 |
|
| 507 |
Marc Lehmann <schmorp@schmorp.de> |
| 508 |
http://software.schmorp.de/pkg/Convert-BER-XS |
| 509 |
|
| 510 |
=cut |
| 511 |
|
