… | |
… | |
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 | my $ber = ber_decode $buf |
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, # constructed, data) |
13 | # (class, tag, # constructed, 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? |
19 | |
19 | |
20 | [ ASN_UNIVERSAL, ASN_SEQUENCE, 1, |
20 | [ ASN_UNIVERSAL, ASN_SEQUENCE, 1, |
21 | [ |
21 | [ |
22 | [ ASN_UNIVERSAL, ASN_INTEGER32, 0, 0 ], # snmp version 1 |
22 | [ ASN_UNIVERSAL, ASN_INTEGER32, 0, 0 ], # snmp version 1 |
23 | [ ASN_UNIVERSAL, 4, 0, "public" ], # community |
23 | [ ASN_UNIVERSAL, 4, 0, "public" ], # community |
24 | [ ASN_CONTEXT, 4, 1, # CHOICE, constructed - trap PDU |
24 | [ ASN_CONTEXT, 4, 1, # CHOICE, constructed - trap PDU |
25 | [ |
25 | [ |
26 | [ ASN_UNIVERSAL, ASN_OBJECT_IDENTIFIER, 0, "1.3.6.1.4.1.9.9.215.2" ], # enterprise oid |
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 |
27 | [ ASN_APPLICATION, SNMP_IPADDRESS, 0, "10.0.0.1" ], # SNMP IpAddress |
28 | [ ASN_UNIVERSAL, ASN_INTEGER32, 0, 6 ], # generic trap |
28 | [ ASN_UNIVERSAL, ASN_INTEGER32, 0, 6 ], # generic trap |
29 | [ ASN_UNIVERSAL, ASN_INTEGER32, 0, 1 ], # specific trap |
29 | [ ASN_UNIVERSAL, ASN_INTEGER32, 0, 1 ], # specific trap |
30 | [ ASN_APPLICATION, ASN_TIMETICKS, 0, 1817903850 ], # SNMP TimeTicks |
30 | [ ASN_APPLICATION, SNMP_TIMETICKS, 0, 1817903850 ], # SNMP TimeTicks |
31 | [ ASN_UNIVERSAL, ASN_SEQUENCE, 1, # the varbindlist |
31 | [ ASN_UNIVERSAL, ASN_SEQUENCE, 1, # the varbindlist |
32 | [ |
32 | [ |
33 | [ ASN_UNIVERSAL, ASN_SEQUENCE, 1, # a single varbind, "key value" pair |
33 | [ ASN_UNIVERSAL, ASN_SEQUENCE, 1, # a single varbind, "key value" pair |
34 | [ |
34 | [ |
35 | [ ASN_UNIVERSAL, ASN_OBJECT_IDENTIFIER, 0, "1.3.6.1.4.1.9.9.215.1.1.8.1.2.1" ], |
35 | [ ASN_UNIVERSAL, ASN_OBJECT_IDENTIFIER, 0, "1.3.6.1.4.1.9.9.215.1.1.8.1.2.1" ], |
… | |
… | |
62 | ) { |
62 | ) { |
63 | ... and so on |
63 | ... and so on |
64 | |
64 | |
65 | # finally, let's encode it again and hope it results in the same bit pattern |
65 | # finally, let's encode it again and hope it results in the same bit pattern |
66 | |
66 | |
67 | my $buf = ber_encode $ber; |
67 | my $buf = ber_encode $ber, $Convert::BER::XS::SNMP_PROFILE; |
68 | |
68 | |
69 | =head1 DESCRIPTION |
69 | =head1 DESCRIPTION |
70 | |
70 | |
71 | WARNING: Before release 1.0, the API is not considered stable in any way. |
71 | WARNING: Before release 1.0, the API is not considered stable in any way. |
72 | |
72 | |
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 | It 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 eyesight with extremely long names, I |
|
|
82 | recommend importing the C<:all> tag. Still, you can selectively import |
|
|
83 | things. |
|
|
84 | |
|
|
85 | =over |
|
|
86 | |
|
|
87 | =item C<:all> |
|
|
88 | |
|
|
89 | All of the below. Really. Recommended for at least first steps, or if you |
|
|
90 | don't care about a few kilobytes of wasted memory (and namespace). |
|
|
91 | |
|
|
92 | =item C<:const> |
|
|
93 | |
|
|
94 | All of the strictly ASN.1-related constants defined by this module, the |
|
|
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: |
|
|
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>, respectively - |
|
|
110 | exactly thw two topmost bits from the identifier octet shifted 6 bits to |
|
|
111 | the right): |
|
|
112 | |
|
|
113 | ASN_UNIVERSAL ASN_APPLICATION ASN_CONTEXT ASN_PRIVATE |
|
|
114 | |
|
|
115 | 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. |
|
|
117 | |
|
|
118 | ASN_BOOLEAN ASN_INTEGER32 ASN_BIT_STRING ASN_OCTET_STRING ASN_NULL ASN_OBJECT_IDENTIFIER |
|
|
119 | ASN_OBJECT_DESCRIPTOR ASN_OID ASN_EXTERNAL ASN_REAL ASN_SEQUENCE ASN_ENUMERATED |
|
|
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 | |
|
|
125 | =item C<:const_ber_type> |
|
|
126 | |
|
|
127 | The BER type constants, explained in the PROFILES section. |
|
|
128 | |
|
|
129 | BER_TYPE_BYTES BER_TYPE_UTF8 BER_TYPE_UCS2 BER_TYPE_UCS4 BER_TYPE_INT |
|
|
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 |
|
|
137 | BER/RFC 2578. |
|
|
138 | |
|
|
139 | SNMP_IPADDRESS SNMP_COUNTER32 SNMP_UNSIGNED32 SNMP_TIMETICKS SNMP_OPAQUE SNMP_COUNTER64 |
|
|
140 | |
|
|
141 | =item C<:decode> |
|
|
142 | |
|
|
143 | C<ber_decode> and the match helper functions: |
|
|
144 | |
|
|
145 | ber_decode ber_is ber_is_seq ber_is_i32 ber_is_oid |
|
|
146 | |
|
|
147 | =item C<:encode> |
|
|
148 | |
|
|
149 | C<ber_encode> and the construction helper functions: |
|
|
150 | |
|
|
151 | ber_encode ber_i32 |
|
|
152 | |
|
|
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 |
101 | applications work around this in different ways, for example, SNMP defines |
175 | applications work around this in different ways, for example, SNMP defines |
102 | application-specific Gauge32, Counter32 and Unsigned32, which are mapped |
176 | application-specific Gauge32, Counter32 and Unsigned32, which are mapped |
103 | to two different tags: you can distinguish between Counter32 and the |
177 | to two different tags: you can distinguish between Counter32 and the |
104 | others, but not between Gause32 and Unsigned32, without the ASN.1 schema. |
178 | others, but not between Gause32 and Unsigned32, without the ASN.1 schema. |
105 | |
179 | |
… | |
… | |
109 | |
183 | |
110 | This module represents every BER value as a 4-element tuple (actually an |
184 | This module represents every BER value as a 4-element tuple (actually an |
111 | array-reference): |
185 | array-reference): |
112 | |
186 | |
113 | [CLASS, TAG, CONSTRUCTED, DATA] |
187 | [CLASS, TAG, CONSTRUCTED, DATA] |
|
|
188 | |
|
|
189 | For example: |
|
|
190 | |
|
|
191 | [ASN_UNIVERSAL, ASN_INTEGER32, 0, 177] # the integer 177 |
|
|
192 | [ASN_UNIVERSAL, ASN_OCTET_STRING, 0, "john"] # the string "john" |
|
|
193 | [ASN_UNIVERSAL, ASN_OID, 0, "1.3.6.133"] # some OID |
|
|
194 | [ASN_UNIVERSAL, ASN_SEQUENCE, 1, [ [ASN_UNIVERSAL... # a sequence |
114 | |
195 | |
115 | To avoid non-descriptive hardcoded array index numbers, this module |
196 | To avoid non-descriptive hardcoded array index numbers, this module |
116 | defines symbolic constants to access these members: C<BER_CLASS>, |
197 | defines symbolic constants to access these members: C<BER_CLASS>, |
117 | C<BER_TAG>, C<BER_CONSTRUCTED> and C<BER_DATA>. |
198 | C<BER_TAG>, C<BER_CONSTRUCTED> and C<BER_DATA>. |
118 | |
199 | |
… | |
… | |
137 | specific applications (for example, the SNMP C<Unsigned32> type is in this |
218 | 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. |
219 | namespace), a special-purpose context namespace (C<ASN_CONTEXT>, used e.g. |
139 | for C<CHOICE>) and a private namespace (C<ASN_PRIVATE>). |
220 | for C<CHOICE>) and a private namespace (C<ASN_PRIVATE>). |
140 | |
221 | |
141 | The meaning of the I<TAG> depends on the namespace, and defines a |
222 | 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 |
223 | (partial) interpretation of the data value. For example, SNMP defines |
143 | application namespace knowledge ix hardcoded into this module, so it |
224 | extra tags in the C<ASN_APPLICATION> namespace, and to take full advantage |
144 | knows that SNMP C<Unsigned32> values need to be decoded into actual perl |
225 | of these, you need to tell this module how to handle those via profiles. |
145 | integers. |
|
|
146 | |
226 | |
147 | The most common tags in the C<ASN_UNIVERSAL> namespace are |
227 | 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>, |
228 | C<ASN_INTEGER32>, C<ASN_BIT_STRING>, C<ASN_NULL>, C<ASN_OCTET_STRING>, |
149 | C<ASN_OBJECT_IDENTIFIER>, C<ASN_SEQUENCE>, C<ASN_SET> and |
229 | C<ASN_OBJECT_IDENTIFIER>, C<ASN_SEQUENCE>, C<ASN_SET> and |
150 | C<ASN_IA5_STRING>. |
230 | C<ASN_IA5_STRING>. |
151 | |
231 | |
152 | The most common tags in SNMP's C<ASN_APPLICATION> namespace |
232 | The most common tags in SNMP's C<ASN_APPLICATION> namespace are |
153 | are C<SNMP_IPADDRESS>, C<SNMP_COUNTER32>, C<SNMP_UNSIGNED32>, |
233 | C<SNMP_COUNTER32>, C<SNMP_UNSIGNED32>, C<SNMP_TIMETICKS> and |
154 | C<SNMP_TIMETICKS>, C<SNMP_OPAQUE> and C<SNMP_COUNTER64>. |
234 | C<SNMP_COUNTER64>. |
155 | |
235 | |
156 | The I<CONSTRUCTED> flag is really just a boolean - if it is false, the |
236 | The I<CONSTRUCTED> flag is really just a boolean - if it is false, |
157 | the value is "primitive" and contains no subvalues, kind of like a |
237 | 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" |
238 | 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 |
239 | which just means it contains a list of subvalues which this module will |
160 | en-/decode as BER tuples themselves. |
240 | en-/decode as BER tuples themselves. |
161 | |
241 | |
162 | The I<DATA> value is either a reference to an array of further tuples (if |
242 | 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, |
243 | the value is I<CONSTRUCTED>), some decoded representation of the value, |
… | |
… | |
172 | |
252 | |
173 | =head2 DECODING AND ENCODING |
253 | =head2 DECODING AND ENCODING |
174 | |
254 | |
175 | =over |
255 | =over |
176 | |
256 | |
177 | =item $tuple = ber_decoded $bindata |
257 | =item $tuple = ber_decoded $bindata[, $profile] |
178 | |
258 | |
179 | Decodes binary BER data in C<$bindata> and returns the resulting BER |
259 | 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 |
260 | tuple. Croaks on any decoding error, so the returned C<$tuple> is always |
181 | valid. |
261 | valid. |
182 | |
262 | |
|
|
263 | How tags are interpreted is defined by the second argument, which must |
|
|
264 | be a C<Convert::BER::XS::Profile> object. If it is missing, the default |
|
|
265 | profile will be used (C<$Convert::BER::XS::DEFAULT_PROFILE>). |
|
|
266 | |
|
|
267 | In addition to rolling your own, this module provides a |
|
|
268 | C<$Convert::BER::XS::SNMP_PROFILE> that knows about the additional SNMP |
|
|
269 | types. |
|
|
270 | |
183 | =item $bindata = ber_encode $tuple |
271 | =item $bindata = ber_encode $tuple[, $profile] |
184 | |
272 | |
185 | Encodes the BER tuple into a BER/DER data structure. |
273 | Encodes the BER tuple into a BER/DER data structure. AS with |
|
|
274 | Cyber_decode>, an optional profile can be given. |
186 | |
275 | |
187 | =back |
276 | =back |
188 | |
277 | |
189 | =head2 HELPER FUNCTIONS |
278 | =head2 HELPER FUNCTIONS |
190 | |
279 | |
191 | Working with a 4-tuple for every value can be annoying. Or, rather, I<is> |
280 | 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 |
281 | 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: |
282 | functions, both to match BER tuples and to construct BER tuples: |
194 | |
283 | |
195 | =head3 MATCH HELPERS |
284 | =head3 MATCH HELPERS |
196 | |
285 | |
197 | Thse functions accept a BER tuple as first argument and either paertially |
286 | These functions accept a BER tuple as first argument and either partially |
198 | or fully match it. They often come in two forms, one which exactly matches |
287 | 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. |
288 | a value, and one which only matches the type and returns the value. |
200 | |
289 | |
201 | They do check whether valid tuples are passed in and croak otherwise. As |
290 | 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 |
291 | 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. |
292 | tuple reference, in which case they silently fail to match. |
204 | |
293 | |
205 | =over |
294 | =over |
206 | |
295 | |
207 | =item $bool = ber_is $tuple, $class, $tag, $constructed, $data |
296 | =item $bool = ber_is $tuple, $class, $tag, $constructed, $data |
208 | |
297 | |
209 | This takes a BER C<$tuple> and matches its elements agains the privded |
298 | This takes a BER C<$tuple> and matches its elements against the provided |
210 | values, all of which are optional - values that are either missing or |
299 | values, all of which are optional - values that are either missing or |
211 | C<undef> will be ignored, the others will be matched exactly (e.g. as if |
300 | C<undef> will be ignored, the others will be matched exactly (e.g. as if |
212 | you used C<==> or C<eq> (for C<$data>)). |
301 | you used C<==> or C<eq> (for C<$data>)). |
213 | |
302 | |
214 | Some examples: |
303 | Some examples: |
… | |
… | |
292 | use Exporter qw(import); |
381 | use Exporter qw(import); |
293 | |
382 | |
294 | our $VERSION; |
383 | our $VERSION; |
295 | |
384 | |
296 | BEGIN { |
385 | BEGIN { |
297 | $VERSION = 0.7; |
386 | $VERSION = 0.8; |
298 | XSLoader::load __PACKAGE__, $VERSION; |
387 | XSLoader::load __PACKAGE__, $VERSION; |
299 | } |
388 | } |
300 | |
389 | |
301 | our %EXPORT_TAGS = ( |
390 | our %EXPORT_TAGS = ( |
302 | const => [qw( |
391 | const_index => [qw( |
303 | BER_CLASS BER_TAG BER_CONSTRUCTED BER_DATA |
392 | BER_CLASS BER_TAG BER_CONSTRUCTED BER_DATA |
304 | |
393 | )], |
|
|
394 | const_asn => [qw( |
305 | ASN_BOOLEAN ASN_INTEGER32 ASN_BIT_STRING ASN_OCTET_STRING ASN_NULL ASN_OBJECT_IDENTIFIER |
395 | 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 |
396 | 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 |
397 | 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 |
398 | 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 |
399 | 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 |
400 | ASN_ISO646_STRING ASN_GENERAL_STRING ASN_UNIVERSAL_STRING ASN_CHARACTER_STRING ASN_BMP_STRING |
311 | |
401 | |
312 | ASN_UNIVERSAL ASN_APPLICATION ASN_CONTEXT ASN_PRIVATE |
402 | ASN_UNIVERSAL ASN_APPLICATION ASN_CONTEXT ASN_PRIVATE |
313 | |
403 | )], |
|
|
404 | const_ber_type => [qw( |
314 | BER_TYPE_BYTES BER_TYPE_UTF8 BER_TYPE_UCS2 BER_TYPE_UCS4 BER_TYPE_INT |
405 | 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 |
406 | BER_TYPE_OID BER_TYPE_RELOID BER_TYPE_NULL BER_TYPE_BOOL BER_TYPE_REAL |
316 | BER_TYPE_IPADDRESS BER_TYPE_CROAK |
407 | BER_TYPE_IPADDRESS BER_TYPE_CROAK |
317 | )], |
408 | )], |
318 | const_snmp => [qw( |
409 | const_snmp => [qw( |
319 | SNMP_IPADDRESS SNMP_COUNTER32 SNMP_UNSIGNED32 SNMP_TIMETICKS SNMP_OPAQUE SNMP_COUNTER64 |
410 | SNMP_IPADDRESS SNMP_COUNTER32 SNMP_UNSIGNED32 SNMP_TIMETICKS SNMP_OPAQUE SNMP_COUNTER64 |
320 | )], |
411 | )], |
321 | encode => [qw( |
412 | decode => [qw( |
322 | ber_decode |
413 | ber_decode |
323 | ber_is ber_is_seq ber_is_i32 ber_is_oid |
414 | ber_is ber_is_seq ber_is_i32 ber_is_oid |
324 | )], |
415 | )], |
325 | decode => [qw( |
416 | encode => [qw( |
326 | ber_encode |
417 | ber_encode |
327 | ber_i32 |
418 | ber_i32 |
328 | )], |
419 | )], |
329 | ); |
420 | ); |
330 | |
421 | |
331 | our @EXPORT_OK = map @$_, values %EXPORT_TAGS; |
422 | our @EXPORT_OK = map @$_, values %EXPORT_TAGS; |
332 | |
423 | |
333 | $EXPORT_TAGS{all} = \@EXPORT_OK; |
424 | $EXPORT_TAGS{all} = \@EXPORT_OK; |
|
|
425 | $EXPORT_TAGS{const} = [map @{ $EXPORT_TAGS{$_} }, qw(const_index const_asn)]; |
|
|
426 | use Data::Dump; ddx \%EXPORT_TAGS; |
334 | |
427 | |
335 | =head1 PROFILES |
428 | =head1 PROFILES |
336 | |
429 | |
337 | While any BER data can be correctly encoded and decoded out of the box, it |
430 | 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" |
431 | can be inconvenient to have to manually decode some values into a "better" |
… | |
… | |
347 | |
440 | |
348 | The default profile supports the standard ASN.1 types, but no |
441 | The default profile supports the standard ASN.1 types, but no |
349 | application-specific ones. This means that class/tag combinations not in |
442 | 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. |
443 | the base set of ASN.1 are decoded into their raw octet strings. |
351 | |
444 | |
352 | C<Convert::BER::XS> defines two profile variables you cna use out of the box: |
445 | C<Convert::BER::XS> defines two profile variables you can use out of the box: |
353 | |
446 | |
354 | =over |
447 | =over |
355 | |
448 | |
356 | =item C<$Convert::BER::XS::DEFAULT_PROFILE> |
449 | =item C<$Convert::BER::XS::DEFAULT_PROFILE> |
357 | |
450 | |
358 | This is the default profile, i.e. the profile that is used when no |
451 | This is the default profile, i.e. the profile that is used when no |
359 | profile is specified for de-/encoding. |
452 | profile is specified for de-/encoding. |
360 | |
453 | |
361 | You cna modify it, but remember that this modifies the defaults for all |
454 | You can modify it, but remember that this modifies the defaults for all |
362 | callers that rely on the defauit profile. |
455 | callers that rely on the default profile. |
363 | |
456 | |
364 | =item C<$Convert::BER::XS::SNMP_PROFILE> |
457 | =item C<$Convert::BER::XS::SNMP_PROFILE> |
365 | |
458 | |
366 | A profile with mappings for SNMP-specific application tags added. This is |
459 | A profile with mappings for SNMP-specific application tags added. This is |
367 | useful when de-/encoding SNMP data. |
460 | useful when de-/encoding SNMP data. |
368 | |
461 | |
369 | Example: |
462 | Example: |
|
|
463 | |
370 | $ber = ber_decode $data, $Convert::BER::XS::SNMP_PROFILE; |
464 | $ber = ber_decode $data, $Convert::BER::XS::SNMP_PROFILE; |
371 | |
465 | |
372 | =back |
466 | =back |
373 | |
467 | |
374 | =head2 The Convert::BER::XS::Profile class |
468 | =head2 The Convert::BER::XS::Profile class |
… | |
… | |
387 | |
481 | |
388 | Note that currently, the mapping is stored in a flat array, so large |
482 | Note that currently, the mapping is stored in a flat array, so large |
389 | values of C<$tag> will consume large amounts of memory. |
483 | values of C<$tag> will consume large amounts of memory. |
390 | |
484 | |
391 | Example: |
485 | Example: |
|
|
486 | |
392 | $profile = new Convert::BER::XS::Profile; |
487 | $profile = new Convert::BER::XS::Profile; |
393 | $profile->set (ASN_APPLICATION, SNMP_COUNTER32, BER_TYPE_INT); |
488 | $profile->set (ASN_APPLICATION, SNMP_COUNTER32, BER_TYPE_INT); |
394 | $ber = ber_decode $data, $profile; |
489 | $ber = ber_decode $data, $profile; |
395 | |
490 | |
396 | =item $type = $profile->get ($class, $tag) |
491 | =item $type = $profile->get ($class, $tag) |
… | |
… | |
419 | string. |
514 | string. |
420 | |
515 | |
421 | =item C<BER_TYPE_UCS2> |
516 | =item C<BER_TYPE_UCS2> |
422 | |
517 | |
423 | Similar to C<BER_TYPE_UTF8>, but treats the BER value as UCS-2 encoded |
518 | Similar to C<BER_TYPE_UTF8>, but treats the BER value as UCS-2 encoded |
424 | string. NOT IMPLEMENTED. |
519 | string. |
425 | |
520 | |
426 | =item C<BER_TYPE_UCS4> |
521 | =item C<BER_TYPE_UCS4> |
427 | |
522 | |
428 | Similar to C<BER_TYPE_UTF8>, but treats the BER value as UCS-4 encoded |
523 | Similar to C<BER_TYPE_UTF8>, but treats the BER value as UCS-4 encoded |
429 | string. NOT IMPLEMENTED. |
524 | string. |
430 | |
525 | |
431 | =item C<BER_TYPE_INT> |
526 | =item C<BER_TYPE_INT> |
432 | |
527 | |
433 | Encodes and decodes a BER integer value to a perl integer scalar. This |
528 | Encodes and decodes a BER integer value to a perl integer scalar. This |
434 | should correctly handle 64 bit signed and unsigned values. |
529 | should correctly handle 64 bit signed and unsigned values. |
… | |
… | |
438 | Encodes and decodes an OBJECT IDENTIFIER into dotted form without leading |
533 | Encodes and decodes an OBJECT IDENTIFIER into dotted form without leading |
439 | dot, e.g. C<1.3.6.1.213>. |
534 | dot, e.g. C<1.3.6.1.213>. |
440 | |
535 | |
441 | =item C<BER_TYPE_RELOID> |
536 | =item C<BER_TYPE_RELOID> |
442 | |
537 | |
443 | Same as C<BER_TYPE_OID> but uses relative OID encoding: ASN.1 has this |
538 | 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 |
539 | 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 |
540 | into a single integer in a weird attempt to save an insignificant amount |
446 | wasteful encoding, and relative OIDs are basically OIDs without this |
541 | of space in an otherwise wasteful encoding, and relative OIDs are |
447 | hack. The practical difference is that the second component of an OID |
542 | 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 |
543 | second component of an OID can only have the values 1..40, while relative |
449 | restriction. |
544 | OIDs do not have this restriction. |
450 | |
545 | |
451 | =item C<BER_TYPE_NULL> |
546 | =item C<BER_TYPE_NULL> |
452 | |
547 | |
453 | Decodes an C<ASN_NULL> value into C<undef>, and always encodes a |
548 | Decodes an C<ASN_NULL> value into C<undef>, and always encodes a |
454 | C<ASN_NULL> type, regardless of the perl value. |
549 | C<ASN_NULL> type, regardless of the perl value. |
… | |
… | |
462 | |
557 | |
463 | Decodes/encodes a BER real value. NOT IMPLEMENTED. |
558 | Decodes/encodes a BER real value. NOT IMPLEMENTED. |
464 | |
559 | |
465 | =item C<BER_TYPE_IPADDRESS> |
560 | =item C<BER_TYPE_IPADDRESS> |
466 | |
561 | |
467 | Decodes/encodes a four byte string into an IOv4 dotted-quad address string |
562 | 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 |
563 | 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, |
564 | 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>. |
565 | so it won't handle all string forms supported by C<inet_aton> for example. |
471 | |
566 | |
472 | =item C<BER_TYPE_CROAK> |
567 | =item C<BER_TYPE_CROAK> |
473 | |
568 | |
474 | Always croaks when encountered during encoding or decoding - the |
569 | Always croaks when encountered during encoding or decoding - the |
475 | default behaviour when encountering an unknown type is to treat it as |
570 | 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 |
571 | 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. |
572 | error for some types, then C<BER_TYPE_CROAK> is for you. |
478 | |
573 | |
479 | =back |
574 | =back |
480 | |
575 | |
481 | =cut |
576 | =cut |
482 | |
577 | |
483 | our $DEFAULT_PROFILE = new Convert::BER::XS::Profile; |
578 | our $DEFAULT_PROFILE = new Convert::BER::XS::Profile; |
484 | our $SNMP_PROFILE = new Convert::BER::XS::Profile; |
579 | our $SNMP_PROFILE = new Convert::BER::XS::Profile; |
485 | |
580 | |
|
|
581 | # additional SNMP application types |
486 | $SNMP_PROFILE->set (ASN_APPLICATION, SNMP_IPADDRESS , BER_TYPE_IPADDRESS); |
582 | $SNMP_PROFILE->set (ASN_APPLICATION, SNMP_IPADDRESS , BER_TYPE_IPADDRESS); |
487 | $SNMP_PROFILE->set (ASN_APPLICATION, SNMP_COUNTER32 , BER_TYPE_INT); |
583 | $SNMP_PROFILE->set (ASN_APPLICATION, SNMP_COUNTER32 , BER_TYPE_INT); |
488 | $SNMP_PROFILE->set (ASN_APPLICATION, SNMP_UNSIGNED32, BER_TYPE_INT); |
584 | $SNMP_PROFILE->set (ASN_APPLICATION, SNMP_UNSIGNED32, BER_TYPE_INT); |
489 | $SNMP_PROFILE->set (ASN_APPLICATION, SNMP_TIMETICKS , BER_TYPE_INT); |
585 | $SNMP_PROFILE->set (ASN_APPLICATION, SNMP_TIMETICKS , BER_TYPE_INT); |
490 | $SNMP_PROFILE->set (ASN_APPLICATION, SNMP_OPAQUE , BER_TYPE_IPADDRESS); |
586 | $SNMP_PROFILE->set (ASN_APPLICATION, SNMP_OPAQUE , BER_TYPE_IPADDRESS); |
… | |
… | |
492 | |
588 | |
493 | $DEFAULT_PROFILE->_set_default; |
589 | $DEFAULT_PROFILE->_set_default; |
494 | |
590 | |
495 | 1; |
591 | 1; |
496 | |
592 | |
497 | =head2 LIMITATIONS |
593 | =head2 LIMITATIONS/NOTES |
498 | |
594 | |
499 | This module can only en-/decode 64 bit signed and unsigned integers, and |
595 | This module can only en-/decode 64 bit signed and unsigned integers, and |
500 | only when your perl supports those. |
596 | only when your perl supports those. |
501 | |
597 | |
|
|
598 | This module does not generally care about ranges, i.e. it will happily |
|
|
599 | de-/encode 64 bit integers into an C<ASN_INTEGER32> value, or a negative |
|
|
600 | number into an C<SNMP_COUNTER64>. |
|
|
601 | |
502 | OBJECT IDENTIFIEERS cannot have unlimited length, although the limit is |
602 | OBJECT IDENTIFIEERs cannot have unlimited length, although the limit is |
503 | much larger than e.g. the one imposed by SNMP or other protocols. |
603 | much larger than e.g. the one imposed by SNMP or other protocols,a nd is |
|
|
604 | about 4kB. |
|
|
605 | |
|
|
606 | REAL values are not supported and will currently croak. |
|
|
607 | |
|
|
608 | This module has undergone little to no testing so far. |
|
|
609 | |
|
|
610 | =head2 ITHREADS SUPPORT |
|
|
611 | |
|
|
612 | This module is unlikely to work when the (officially discouraged) ithreads |
|
|
613 | are in use. |
504 | |
614 | |
505 | =head1 AUTHOR |
615 | =head1 AUTHOR |
506 | |
616 | |
507 | Marc Lehmann <schmorp@schmorp.de> |
617 | Marc Lehmann <schmorp@schmorp.de> |
508 | http://software.schmorp.de/pkg/Convert-BER-XS |
618 | http://software.schmorp.de/pkg/Convert-BER-XS |