1asn(n) ASN.1 processing asn(n)
2______________________________________________________________________________
6
8 asn - ASN.1 BER encoder/decoder
9
11 package require Tcl 8.4
12 package require asn ?0.7?
14 ::asn::asnSequence evalue...
16 ::asn::asnSequenceFromList elist
18 ::asn::asnSet evalue...
20 ::asn::asnSet elist
22 ::asn::asnApplicationConstr appNumber evalue...
24 ::asn::asnApplication appNumber data
26 ::asn::asnChoice appNumber evalue...
28 ::asn::asnChoiceConstr appNumber evalue...
30 ::asn::asnInteger number
32 ::asn::asnEnumeration number
34 ::asn::asnBoolean bool
36 ::asn::asnOctetString string
38 ::asn::asnNumericString string
40 ::asn::asnPrintableString string
42 ::asn::asnIA5String string
44 ::asn::asnBMPString string
46 ::asn::asnUTF8String string
48 ::asn::asnString string
50 ::asn::defaultStringType ?type?
52 ::asn::asnPeekByte data_var byte_var
54 ::asn::asnRetag data_var newTag
56 ::asn::asnGetLength data_var length_var
58 ::asn::asnGetResponse chan data_var
60 ::asn::asnGetInteger data_var int_var
62 ::asn::asnGetEnumeration data_var enum_var
64 ::asn::asnGetOctetString data_var string_var
66 ::asn::asnGetString data_var string_var ?type_var?
68 ::asn::asnGetNumericString data_var string_var
70 ::asn::asnGetPrintableString data_var string_var
72 ::asn::asnGetIA5String data_var string_var
74 ::asn::asnGetBMPString data_var string_var
76 ::asn::asnGetUTF8String data_var string_var
78 ::asn::asnGetUTCTime data_var utc_var
80 ::asn::asnGetBitString data_var bits_var
82 ::asn::asnGetObjectIdentifier data_var oid_var
84 ::asn::asnGetBoolean data_var bool_var
86 ::asn::asnGetNull data_var
88 ::asn::asnGetSequence data_var sequence_var
90 ::asn::asnGetSet data_var set_var
92 ::asn::asnGetApplication data_var appNumber_var ?content_var?
94 ::asn::asnGetContext data_var contextNumber_var ?content_var?
96_________________________________________________________________
98
100 The asn package provides partial de- and encoder commands for BER
101 encoded ASN.1 data.
102 ASN.1 is a standard Abstract Syntax Notation, and BER are its Basic
104 Encoding Rules.
105 See http://asn1.elibel.tm.fr/en/standards/index.htm for more informa‐
107 tion about the standard.
108 Also see http://luca.ntop.org/Teaching/Appunti/asn1.html for A Layman's
110 Guide to a Subset of ASN.1, BER, and DER, an RSA Laboratories Technical
111 Note by Burton S. Kaliski Jr. (Revised November 1, 1993). A text ver‐
112 sion of this note is part of the module sources and should be read by
113 any implementor.
114
116 ENCODER
117 ::asn::asnSequence evalue...
118 Takes zero or more encoded values, packs them into an ASN
119 sequence and returns its encoded binary form.
120 ::asn::asnSequenceFromList elist
122 Takes a list of encoded values, packs them into an ASN sequence
123 and returns its encoded binary form.
124 ::asn::asnSet evalue...
126 Takes zero or more encoded values, packs them into an ASN set
127 and returns its encoded binary form.
128 ::asn::asnSet elist
130 Takes a list of encoded values, packs them into an ASN set and
131 returns its encoded binary form.
132 ::asn::asnApplicationConstr appNumber evalue...
134 Takes zero or more encoded values, packs them into an ASN appli‐
135 cation construct and returns its encoded binary form.
136 ::asn::asnApplication appNumber data
138 Takes a single encoded value data, packs it into an ASN applica‐
139 tion construct and returns its encoded binary form.
140 ::asn::asnChoice appNumber evalue...
142 Takes zero or more encoded values, packs them into an ASN choice
143 construct and returns its encoded binary form.
144 ::asn::asnChoiceConstr appNumber evalue...
146 Takes zero or more encoded values, packs them into an ASN choice
147 construct and returns its encoded binary form.
148 ::asn::asnInteger number
150 Returns the encoded form of the specified integer number.
151 ::asn::asnEnumeration number
153 Returns the encoded form of the specified enumeration id number.
154 ::asn::asnBoolean bool
156 Returns the encoded form of the specified boolean value bool.
157 ::asn::asnOctetString string
159 Returns the encoded form of the specified string.
160 ::asn::asnNumericString string
162 Returns the string encoded as ASN.1 NumericString. Raises an
163 error if the string contains characters other than decimal num‐
164 bers and space.
165 ::asn::asnPrintableString string
167 Returns the string encoding as ASN.1 PrintableString. Raises an
168 error if the string contains characters which are not allowed by
169 the Printable String datatype. The allowed characters are A-Z,
170 a-z, 0-9, space, apostrophe, colon, parentheses, plus, minus,
171 comma, period, forward slash, question mark, and the equals
172 sign.
173 ::asn::asnIA5String string
175 Returns the string encoded as ASN.1 IA5String. Raises an error
176 if the string contains any characters outside of the US-ASCII
177 range.
178 ::asn::asnBMPString string
180 Returns the string encoded as ASN.1 Basic Multilingual Plane
181 string (Which is essentialy big-endian UCS2).
182 ::asn::asnUTF8String string
184 Returns the string encoded as UTF8 String. Note that some legacy
185 applications such as Windows CryptoAPI do not like UTF8 strings.
186 Use BMPStrings if you are not sure.
187 ::asn::asnString string
189 Returns an encoded form of string, choosing the most restricted
190 ASN.1 string type possible. If the string contains non-ASCII
191 characters, then there is more than one string type which can be
192 used. See ::asn::defaultStringType.
193 ::asn::defaultStringType ?type?
195 Selects the string type to use for the encoding of non-ASCII
196 strings. Returns current default when called without argument.
197 If the argument type is supplied, it should be either UTF8 or
198 BMP to choose UTF8String or BMPString respectively.
199 DECODER
201 General notes:
202 [1] Nearly decoder commands take two arguments. These arguments are
204 variable names, except for ::asn::asnGetResponse. The first
205 variable contains the encoded ASN value to decode at the begin‐
206 ning, and more, and the second variable is where the value is
207 stored to. The remainder of the input after the decoded value is
208 stored back into the datavariable.
209 [2] After extraction the data variable is always modified first,
211 before by writing the extracted value to its variable. This
212 means that if both arguments refer to the same variable, it will
213 always contain the extracted value after the call, and not the
214 remainder of the input.
215 ::asn::asnPeekByte data_var byte_var
217 Retrieve the first byte of the data, without modifing data_var.
218 This can be used to check for implicit tags.
219 ::asn::asnRetag data_var newTag
221 Replace the tag in front of the data with newTag. Use to handle
222 implicitely tagged data before further decoding.
223 ::asn::asnGetLength data_var length_var
225 Decode the length information for a block of BER data. The tag
226 has already to be removed from the data.
227 ::asn::asnGetResponse chan data_var
229 Reads an encoded ASN sequence from the channel chan and stores
230 it into the variable named by data_var.
231 ::asn::asnGetInteger data_var int_var
233 Assumes that an encoded integer value is at the front of the
234 data stored in the variable named data_var, extracts and stores
235 it into the variable named by int_var. Additionally removes all
236 bytes associated with the value from the data for further pro‐
237 cessing by the following decoder commands.
238 ::asn::asnGetEnumeration data_var enum_var
240 Assumes that an enumeration id is at the front of the data
241 stored in the variable named data_var, and stores it into the
242 variable named by enum_var. Additionally removes all bytes asso‐
243 ciated with the value from the data for further processing by
244 the following decoder commands.
245 ::asn::asnGetOctetString data_var string_var
247 Assumes that a string is at the front of the data stored in the
248 variable named data_var, and stores it into the variable named
249 by string_var. Additionally removes all bytes associated with
250 the value from the data for further processing by the following
251 decoder commands.
252 ::asn::asnGetString data_var string_var ?type_var?
254 Decodes a user-readable string. This is a convenience function
255 which is able to automatically distinguish all supported ASN.1
256 string types and convert the input value appropriately. See
257 ::asn::asnGetPrintableString, ::asnGetIA5String, etc. below for
258 the type-specific conversion commands.
259 If the optional third argument type_var is supplied, then the
261 type of the incoming string is stored in the variable named by
262 it.
263 The function throws the error "Invalid command name asnGetSome‐
265 UnsupportedString" if the unsupported string type Unsupported is
266 encountered. You can create the appropriate function
267 "asn::asnGetSomeUnsupportedString" in your application if nec‐
268 cessary.
269 ::asn::asnGetNumericString data_var string_var
271 Assumes that a numeric string value is at the front of the data
272 stored in the variable named data_var, and stores it into the
273 variable named by string_var. Additionally removes all bytes
274 associated with the value from the data for further processing
275 by the following decoder commands.
276 ::asn::asnGetPrintableString data_var string_var
278 Assumes that a printable string value is at the front of the
279 data stored in the variable named data_var, and stores it into
280 the variable named by string_var. Additionally removes all bytes
281 associated with the value from the data for further processing
282 by the following decoder commands.
283 ::asn::asnGetIA5String data_var string_var
285 Assumes that a IA5 (ASCII) string value is at the front of the
286 data stored in the variable named data_var, and stores it into
287 the variable named by string_var. Additionally removes all bytes
288 associated with the value from the data for further processing
289 by the following decoder commands.
290 ::asn::asnGetBMPString data_var string_var
292 Assumes that a BMP (two-byte unicode) string value is at the
293 front of the data stored in the variable named data_var, and
294 stores it into the variable named by string_var, converting it
295 into a proper Tcl string. Additionally removes all bytes associ‐
296 ated with the value from the data for further processing by the
297 following decoder commands.
298 ::asn::asnGetUTF8String data_var string_var
300 Assumes that a UTF8 string value is at the front of the data
301 stored in the variable named data_var, and stores it into the
302 variable named by string_var, converting it into a proper Tcl
303 string. Additionally removes all bytes associated with the
304 value from the data for further processing by the following
305 decoder commands.
306 ::asn::asnGetUTCTime data_var utc_var
308 Assumes that a UTC time value is at the front of the data stored
309 in the variable named data_var, and stores it into the variable
310 named by utc_var. The UTC time value is stored as a string,
311 which has to be decoded with the usual clock scan commands.
312 Additionally removes all bytes associated with the value from
313 the data for further processing by the following decoder com‐
314 mands.
315 ::asn::asnGetBitString data_var bits_var
317 Assumes that a bit string value is at the front of the data
318 stored in the variable named data_var, and stores it into the
319 variable named by bits_var as a string containing only 0 and 1.
320 Additionally removes all bytes associated with the value from
321 the data for further processing by the following decoder com‐
322 mands.
323 ::asn::asnGetObjectIdentifier data_var oid_var
325 Assumes that a object identifier (OID) value is at the front of
326 the data stored in the variable named data_var, and stores it
327 into the variable named by oid_var as a list of integers. Addi‐
328 tionally removes all bytes associated with the value from the
329 data for further processing by the following decoder commands.
330 ::asn::asnGetBoolean data_var bool_var
332 Assumes that a boolean value is at the front of the data stored
333 in the variable named data_var, and stores it into the variable
334 named by bool_var. Additionally removes all bytes associated
335 with the value from the data for further processing by the fol‐
336 lowing decoder commands.
337 ::asn::asnGetNull data_var
339 Assumes that a NULL value is at the front of the data stored in
340 the variable named data_var and removes the bytes used to encode
341 it from the data.
342 ::asn::asnGetSequence data_var sequence_var
344 Assumes that an ASN sequence is at the front of the data stored
345 in the variable named data_var, and stores it into the variable
346 named by sequence_var. Additionally removes all bytes associated
347 with the value from the data for further processing by the fol‐
348 lowing decoder commands.
349 The data in sequence_var is encoded binary and has to be further
351 decoded according to the definition of the sequence, using the
352 decoder commands here.
353 ::asn::asnGetSet data_var set_var
355 Assumes that an ASN set is at the front of the data stored in
356 the variable named data_var, and stores it into the variable
357 named by set_var. Additionally removes all bytes associated with
358 the value from the data for further processing by the following
359 decoder commands.
360 The data in set_var is encoded binary and has to be further
362 decoded according to the definition of the set, using the
363 decoder commands here.
364 ::asn::asnGetApplication data_var appNumber_var ?content_var?
366 Assumes that an ASN application construct is at the front of the
367 data stored in the variable named data_var, and stores its id
368 into the variable named by appNumber_var. Additionally removes
369 all bytes associated with the value from the data for further
370 processing by the following decoder commands. If a content_var
371 is specified, then the command places all data associated with
372 it into the named variable, in the binary form which can be pro‐
373 cessed using the decoder commands of this package.
374 Otherwise it is the responsibility of the caller to decode the
376 remainder of the application construct based on the id retrieved
377 by this command, using the decoder commands of this package.
378 ::asn::asnGetContext data_var contextNumber_var ?content_var?
380 Assumes that an ASN context tag construct is at the front of the
381 data stored in the variable named data_var, and stores its id
382 into the variable named by contextNumber_var. Additionally
383 removes all bytes associated with the value from the data for
384 further processing by the following decoder commands. If a con‐
385 tent_var is specified, then the command places all data associ‐
386 ated with it into the named variable, in the binary form which
387 can be processed using the decoder commands of this package.
388 Otherwise it is the responsibility of the caller to decode the
390 remainder of the construct based on the id retrieved by this
391 command, using the decoder commands of this package.
392
394 Examples for the usage of this package can be found in the implementa‐
395 tion of package ldap.
396
398 asn, ber, cer, der, internet, protocol, x.208, x.209
399
401 Copyright (c) 2004 Andreas Kupries <andreas_kupries@users.sourceforge.net>
402 Copyright (c) 2004 Jochen Loewer <loewerj@web.de>
403 Copyright (c) 2004-2006 Michael Schlenker <mic42@users.sourceforge.net>
404asn 0.7 asn(n)