public interface Extension
This interface represents an X.509 extension.
Extensions provide a means of associating additional attributes with users or public keys and for managing a certification hierarchy. The extension format also allows communities to define private extensions to carry information unique to those communities.
Each extension contains an object identifier, a criticality setting indicating whether it is a critical or a non-critical extension, and an ASN.1 DER-encoded value. Its ASN.1 definition is:
Extension ::= SEQUENCE { extnId OBJECT IDENTIFIER, critical BOOLEAN DEFAULT FALSE, extnValue OCTET STRING -- contains a DER encoding of a value -- of the type registered for use with -- the extnId object identifier value }
This interface is designed to provide access to a single extension,
unlike X509Extension
which is more suitable
for accessing a set of extensions.
- Since:
- 1.7
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Method Summary
Modifier and TypeMethodDescriptionvoid
encode
(OutputStream out) Generates the extension's DER encoding and writes it to the output stream.getId()
Gets the extensions's object identifier.byte[]
getValue()
Gets the extensions's DER-encoded value.boolean
Gets the extension's criticality setting.
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Method Details
-
getId
-
isCritical
boolean isCritical()Gets the extension's criticality setting.- Returns:
- true if this is a critical extension.
-
getValue
byte[] getValue()Gets the extensions's DER-encoded value. Note, this is the bytes that are encoded as an OCTET STRING. It does not include the OCTET STRING tag and length.- Returns:
- a copy of the extension's value, or
null
if no extension value is present.
-
encode
Generates the extension's DER encoding and writes it to the output stream.- Parameters:
out
- the output stream- Throws:
IOException
- on encoding or output error.NullPointerException
- ifout
isnull
.
-