Distinguished Encoding Rules: Difference between revisions
Content deleted Content added
m "tag order" -> "tag value" |
Tom.Reding (talk | contribs) m +{{Redirect category shell}} using AWB |
||
| (11 intermediate revisions by 7 users not shown) | |||
| Line 1: | Line 1: | ||
#REDIRECT [[X.690#DER encoding]] |
|||
{{Citations missing|date=June 2008}} |
|||
'''Distinguished Encoding Rules (DER)''', is a message transfer syntax specified by the [[ITU]] in X.690. The Distinguished Encoding Rules of [[ASN.1]] is an International Standard drawn from the constraints placed on [[basic encoding rules|basic encoding rules (BER)]] encodings by X.509. DER encodings are valid BER encodings. DER is the same thing as BER with all but one sender's options removed. |
|||
{{Redirect category shell|1= |
|||
DER is a subset of Basic Encoding Rules (BER) providing for exactly one way to encode an ASN.1 value. DER is intended for situations when a unique encoding is needed, such as in in [[cryptography]] and ensures that a data structure that needs to be digitally signed produces a unique serialized representation. DER can be seen as a [[canonical form]] of BER (see also [[Canonical Encoding Rules]]). |
|||
{{R from merge}} |
|||
}} |
|||
For example, in BER a [[boolean]] value of true can be encoded as any of 255 non-zero byte values, while in DER there is only one way to encode a boolean value of true. |
|||
The most significant DER encoding constraints are: |
|||
# Length encoding must use the definite form |
|||
#* Additionally, the shortest possible length encoding must be used |
|||
# Bitstring, octetstring, and restricted character strings must use the definite length form |
|||
# Elements of a Set are encoded in sorted order, based on their tag value |
|||
DER is widely used for digital certificates such as [[X.509]]. |
|||
==External links== |
|||
*[http://www.itu.int/ITU-T/studygroups/com17/languages/X.690-0207.pdf DER standard in PDF] |
|||
*[http://www.rsa.com/products/bsafe/documentation/certj212html/certj/dev_guide/group__CERTJ__STDS__ENCODING.html ASN.1 BER and DER Encoding] |
|||
[[Category:ITU-T recommendations]] |
|||
[[fr:Distinguished Encoding Rules]] |
[[fr:Distinguished Encoding Rules]] |
||
Latest revision as of 03:57, 7 June 2017
Redirect to:
This page is a redirect. The following categories are used to track and monitor this redirect:
|