>>> crt, tail = Certificate().decode(raw)
>>> crt
- Certificate SEQUENCE[TBSCertificate SEQUENCE[[0] EXPLICIT Version
- INTEGER v3 OPTIONAL, CertificateSerialNumber INTEGER 61595,
- AlgorithmIdentifier SEQUENCE[OBJECT IDENTIFIER 1.2.840.113549.1.1.5...
+ Certificate SEQUENCE[tbsCertificate: TBSCertificate SEQUENCE[
+ version: [0] EXPLICIT Version INTEGER v3 OPTIONAL;
+ serialNumber: CertificateSerialNumber INTEGER 61595;
+ signature: AlgorithmIdentifier SEQUENCE[OBJECT IDENTIFIER 1.2.840.113549.1.1.5...
Pretty printing
---------------
::
- 52-2 [1,1,1054]-4 . . . . eContent: [0] EXPLICIT BER OCTET STRING 1046 bytes
+ 52-2∞ [1,1,1054]∞ . . . . eContent: [0] EXPLICIT BER OCTET STRING 1046 bytes
^ ^ ^ ^
12 13 9 10
:0:
- Offset of the object, where its DER encoding begins.
+ Offset of the object, where its DER/BER encoding begins.
Pay attention that it does **not** include explicit tag.
:1:
If explicit tag exists, then this is its length (tag + encoded length).
Possible other flags like OPTIONAL and DEFAULT, if value equals to the
default one, specified in the schema.
:12:
- Only applicable to BER encoded data. If object has indefinite length
- encoding, then subtract 2 bytes EOC from its length. If object has
- explicit tag with indefinite length, then subtract another EOC bytes.
- In example above, ``eContent`` field has both indefinite field encoding
- and indefinite length explicit tag. ``BIT STRING``, ``OCTET STRING``
- (and its derivatives), ``SEQUENCE``, ``SET``, ``SEQUENCE OF``, ``SET
- OF``, ``ANY`` could have indefinite length coding.
+ Only applicable to BER encoded data. Indefinite length encoding mark.
:13:
Only applicable to BER encoded data. If object has BER-specific
encoding, then ``BER`` will be shown. It does not depend on indefinite
- length encoding. ``BOOLEAN``, ``BIT STRING``, ``OCTET STRING`` (and its
- derivatives) could be BERed.
+ length encoding. ``EOC``, ``BOOLEAN``, ``BIT STRING``, ``OCTET STRING``
+ (and its derivatives) could be BERed.
As command line utility
-----------------------
-You can decode DER files using command line abilities and get the same
-picture as above by executing::
+You can decode DER/BER files using command line abilities and get the
+same picture as above by executing::
% python -m pyderasn --schema tests.test_crts:Certificate path/to/file
. . . 9E:12:F7:AA:83:10:BD:D1:7C:98:FA:C7:AE:D4:0E:2C
[...]
+Human readable OIDs
+___________________
+
If you have got dictionaries with ObjectIdentifiers, like example one
from ``tests/test_crts.py``::
79 [1,1, 9] . . . . . . . . . . >: PrintableString PrintableString Barcelona
[...]
+Decode paths
+____________
+
+Each decoded element has so-called decode path: sequence of structure
+names it is passing during the decode process. Each element has its own
+unique path inside the whole ASN.1 tree. You can print it out with
+``--print-decode-path`` option::
+
+ % python -m pyderasn --schema path.to:Certificate --print-decode-path path/to/file
+ 0 [1,3,1604] Certificate SEQUENCE []
+ 4 [1,3,1453] . tbsCertificate: TBSCertificate SEQUENCE [tbsCertificate]
+ 10-2 [1,1, 1] . . version: [0] EXPLICIT Version INTEGER v3 OPTIONAL [tbsCertificate:version]
+ 13 [1,1, 3] . . serialNumber: CertificateSerialNumber INTEGER 61595 [tbsCertificate:serialNumber]
+ 18 [1,1, 13] . . signature: AlgorithmIdentifier SEQUENCE [tbsCertificate:signature]
+ 20 [1,1, 9] . . . algorithm: OBJECT IDENTIFIER 1.2.840.113549.1.1.5 [tbsCertificate:signature:algorithm]
+ 31 [0,0, 2] . . . parameters: [UNIV 5] ANY OPTIONAL [tbsCertificate:signature:parameters]
+ . . . . 05:00
+ 33 [0,0, 278] . . issuer: Name CHOICE rdnSequence [tbsCertificate:issuer]
+ 33 [1,3, 274] . . . rdnSequence: RDNSequence SEQUENCE OF [tbsCertificate:issuer:rdnSequence]
+ 37 [1,1, 11] . . . . 0: RelativeDistinguishedName SET OF [tbsCertificate:issuer:rdnSequence:0]
+ 39 [1,1, 9] . . . . . 0: AttributeTypeAndValue SEQUENCE [tbsCertificate:issuer:rdnSequence:0:0]
+ 41 [1,1, 3] . . . . . . type: AttributeType OBJECT IDENTIFIER 2.5.4.6 [tbsCertificate:issuer:rdnSequence:0:0:type]
+ 46 [0,0, 4] . . . . . . value: [UNIV 19] AttributeValue ANY [tbsCertificate:issuer:rdnSequence:0:0:value]
+ . . . . . . . 13:02:45:53
+ 46 [1,1, 2] . . . . . . . DEFINED BY 2.5.4.6: CountryName PrintableString ES [tbsCertificate:issuer:rdnSequence:0:0:value:DEFINED BY 2.5.4.6]
+ [...]
+
+Now you can print only the specified tree, for example signature algorithm::
+
+ % python -m pyderasn --schema path.to:Certificate --decode-path-only tbsCertificate:signature path/to/file
+ 18 [1,1, 13] AlgorithmIdentifier SEQUENCE
+ 20 [1,1, 9] . algorithm: OBJECT IDENTIFIER 1.2.840.113549.1.1.5
+ 31 [0,0, 2] . parameters: [UNIV 5] ANY OPTIONAL
+ . . 05:00
+
Descriptive errors
------------------
-If you have bad DER, then errors will show you where error occurred::
+If you have bad DER/BER, then errors will show you where error occurred::
% python -m pyderasn --schema tests.test_crts:Certificate path/to/bad/file
Traceback (most recent call last):
[...]
- pyderasn.DecodeError: UTCTime (tbsCertificate.validity.notAfter.utcTime) (at 328) invalid UTCTime format
+ pyderasn.DecodeError: UTCTime (tbsCertificate:validity:notAfter:utcTime) (at 328) invalid UTCTime format
::
% python -m pyderasn path/to/bad/file
[...]
- pyderasn.DecodeError: UTCTime (0.SequenceOf.4.SequenceOf.1.UTCTime) (at 328) invalid UTCTime format
+ pyderasn.DecodeError: UTCTime (0:SequenceOf:4:SequenceOf:1:UTCTime) (at 328) invalid UTCTime format
You can see, so called, decode path inside the structures:
``tbsCertificate`` -> ``validity`` -> ``notAfter`` -> ``utcTime`` and