<https://golang.org/pkg/encoding/asn1/>`__ test suite (assuming that
it's DER encoded representation is already in ``raw`` variable)::
- >>> crt, tail = Certificate().decode(raw)
+ >>> crt = Certificate().decod(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...
-
-Pretty printing
----------------
-
-There is huge output. Let's pretty print it::
-
- >>> print(pprint(crt))
- 0 [1,3,1604] Certificate SEQUENCE
- 4 [1,3,1453] . tbsCertificate: TBSCertificate SEQUENCE
- 10-2 [1,1, 1] . . version: [0] EXPLICIT Version INTEGER v3 OPTIONAL
- 13 [1,1, 3] . . serialNumber: CertificateSerialNumber INTEGER 61595
- 18 [1,1, 13] . . signature: 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
- 33 [0,0, 278] . . issuer: Name CHOICE rdnSequence
- 33 [1,3, 274] . . . rdnSequence: RDNSequence SEQUENCE OF
- 37 [1,1, 11] . . . . 0: RelativeDistinguishedName SET OF
- 39 [1,1, 9] . . . . . 0: AttributeTypeAndValue SEQUENCE
- 41 [1,1, 3] . . . . . . type: AttributeType OBJECT IDENTIFIER 2.5.4.6
- 46 [0,0, 4] . . . . . . value: [UNIV 19] AttributeValue ANY
- . . . . . . . 13:02:45:53
- [...]
- 1461 [1,1, 13] . signatureAlgorithm: AlgorithmIdentifier SEQUENCE
- 1463 [1,1, 9] . . algorithm: OBJECT IDENTIFIER 1.2.840.113549.1.1.5
- 1474 [0,0, 2] . . parameters: [UNIV 5] ANY OPTIONAL
- . . . 05:00
- 1476 [1,2, 129] . signatureValue: BIT STRING 1024 bits
- . . 68:EE:79:97:97:DD:3B:EF:16:6A:06:F2:14:9A:6E:CD
- . . 9E:12:F7:AA:83:10:BD:D1:7C:98:FA:C7:AE:D4:0E:2C
- [...]
-
- Trailing data: 0a
-
-Let's parse that output, human::
+ 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...
- 10-2 [1,1, 1] . . version: [0] EXPLICIT Version INTEGER v3 OPTIONAL
- ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^
- 0 1 2 3 4 5 6 7 8 9 10 11
-
-::
-
- 20 [1,1, 9] . . . algorithm: OBJECT IDENTIFIER 1.2.840.113549.1.1.5
- ^ ^ ^ ^ ^ ^ ^ ^
- 0 2 3 4 5 6 9 10
-
-::
-
- 33 [0,0, 278] . . issuer: Name CHOICE rdnSequence
- ^ ^ ^ ^ ^ ^ ^ ^ ^
- 0 2 3 4 5 6 8 9 10
-
-:0:
- Offset of the object, where its DER encoding begins.
- Pay attention that it does **not** include explicit tag.
-:1:
- If explicit tag exists, then this is its length (tag + encoded length).
-:2:
- Length of object's tag. For example CHOICE does not have its own tag,
- so it is zero.
-:3:
- Length of encoded length.
-:4:
- Length of encoded value.
-:5:
- Visual indentation to show the depth of object in the hierarchy.
-:6:
- Object's name inside SEQUENCE/CHOICE.
-:7:
- If either IMPLICIT or EXPLICIT tag is set, then it will be shown
- here. "IMPLICIT" is omitted.
-:8:
- Object's class name, if set. Omitted if it is just an ordinary simple
- value (like with ``algorithm`` in example above).
-:9:
- Object's ASN.1 type.
-:10:
- Object's value, if set. Can consist of multiple words (like OCTET/BIT
- STRINGs above). We see ``v3`` value in Version, because it is named.
- ``rdnSequence`` is the choice of CHOICE type.
-:11:
- Possible other flags like OPTIONAL and DEFAULT, if value equals to the
- default one, specified in the schema.
+.. seealso:: :ref:`Better pretty printing <pprint_example>`
As command line utility
-----------------------
-You can decode DER 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
-
-If there is no schema for you file, then you can try parsing it without,
-but of course IMPLICIT tags will often make it impossible. But result is
-good enough for the certificate above::
-
- % python -m pyderasn path/to/file
- 0 [1,3,1604] . >: SEQUENCE OF
- 4 [1,3,1453] . . >: SEQUENCE OF
- 8 [0,0, 5] . . . . >: [0] ANY
- . . . . . A0:03:02:01:02
- 13 [1,1, 3] . . . . >: INTEGER 61595
- 18 [1,1, 13] . . . . >: SEQUENCE OF
- 20 [1,1, 9] . . . . . . >: OBJECT IDENTIFIER 1.2.840.113549.1.1.5
- 31 [1,1, 0] . . . . . . >: NULL
- 33 [1,3, 274] . . . . >: SEQUENCE OF
- 37 [1,1, 11] . . . . . . >: SET OF
- 39 [1,1, 9] . . . . . . . . >: SEQUENCE OF
- 41 [1,1, 3] . . . . . . . . . . >: OBJECT IDENTIFIER 2.5.4.6
- 46 [1,1, 2] . . . . . . . . . . >: PrintableString PrintableString ES
- [...]
- 1409 [1,1, 50] . . . . . . >: SEQUENCE OF
- 1411 [1,1, 8] . . . . . . . . >: OBJECT IDENTIFIER 1.3.6.1.5.5.7.1.1
- 1421 [1,1, 38] . . . . . . . . >: OCTET STRING 38 bytes
- . . . . . . . . . 30:24:30:22:06:08:2B:06:01:05:05:07:30:01:86:16
- . . . . . . . . . 68:74:74:70:3A:2F:2F:6F:63:73:70:2E:69:70:73:63
- . . . . . . . . . 61:2E:63:6F:6D:2F
- 1461 [1,1, 13] . . >: SEQUENCE OF
- 1463 [1,1, 9] . . . . >: OBJECT IDENTIFIER 1.2.840.113549.1.1.5
- 1474 [1,1, 0] . . . . >: NULL
- 1476 [1,2, 129] . . >: BIT STRING 1024 bits
- . . . 68:EE:79:97:97:DD:3B:EF:16:6A:06:F2:14:9A:6E:CD
- . . . 9E:12:F7:AA:83:10:BD:D1:7C:98:FA:C7:AE:D4:0E:2C
- [...]
-
-If you have got dictionaries with ObjectIdentifiers, like example one
-from ``tests/test_crts.py``::
-
- some_oids = {
- "1.2.840.113549.1.1.1": "id-rsaEncryption",
- "1.2.840.113549.1.1.5": "id-sha1WithRSAEncryption",
- [...]
- "2.5.4.10": "id-at-organizationName",
- "2.5.4.11": "id-at-organizationalUnitName",
- }
-
-then you can pass it to pretty printer to see human readable OIDs::
-
- % python -m pyderasn --oids tests.test_crts:some_oids path/to/file
- [...]
- 37 [1,1, 11] . . . . . . >: SET OF
- 39 [1,1, 9] . . . . . . . . >: SEQUENCE OF
- 41 [1,1, 3] . . . . . . . . . . >: OBJECT IDENTIFIER id-at-countryName (2.5.4.6)
- 46 [1,1, 2] . . . . . . . . . . >: PrintableString PrintableString ES
- 50 [1,1, 18] . . . . . . >: SET OF
- 52 [1,1, 16] . . . . . . . . >: SEQUENCE OF
- 54 [1,1, 3] . . . . . . . . . . >: OBJECT IDENTIFIER id-at-stateOrProvinceName (2.5.4.8)
- 59 [1,1, 9] . . . . . . . . . . >: PrintableString PrintableString Barcelona
- 70 [1,1, 18] . . . . . . >: SET OF
- 72 [1,1, 16] . . . . . . . . >: SEQUENCE OF
- 74 [1,1, 3] . . . . . . . . . . >: OBJECT IDENTIFIER id-at-localityName (2.5.4.7)
- 79 [1,1, 9] . . . . . . . . . . >: PrintableString PrintableString Barcelona
- [...]
+.. seealso:: :ref:`cmdline`
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
+ $ 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
+ $ 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
tbs["validity"] = validity
spki = SubjectPublicKeyInfo()
- spki_algo_id = sign_algo_id.copy()
+ spki_algo_id = copy(sign_algo_id)
spki_algo_id["algorithm"] = ObjectIdentifier("1.2.840.113549.1.1.1")
spki["algorithm"] = spki_algo_id
spki["subjectPublicKey"] = BitString(hexdec("".join((
class AttributeTypeAndValue(Sequence):
schema = (
- ((("type",), AttributeType(defines=("value", {
+ ((("type",), AttributeType(defines=((("value",), {
id_at_countryName: PrintableString(),
id_at_stateOrProvinceName: PrintableString(),
id_at_localityName: PrintableString(),
id_at_organizationName: PrintableString(),
id_at_commonName: PrintableString(),
- }))),),
+ }),)))),
("value", AttributeValue()),
)
. . . . . . . 74:73:20:50:74:79:20:4C:74:64
95 [1,1, 24] . . . . . . . DEFINED BY (2.5.4.10): PrintableString PrintableString Internet Widgits Pty Ltd
-:ref:`Read more <definedby>` about that feature.
+.. seealso:: :ref:`definedby`
+
+Streaming and dealing with huge structures
+------------------------------------------
+.. seealso:: :ref:`streaming`