RecipientKeyIdentifier (Bouncy Castle Library 1.85 API Specification)
Date: 2026-07-12

org.bouncycastle.asn1.cms

## Class RecipientKeyIdentifier

- java.lang.Object
- - org.bouncycastle.asn1.ASN1Object
  - - org.bouncycastle.asn1.cms.RecipientKeyIdentifier

- All Implemented Interfaces:
    ASN1Encodable, Encodable

      public class RecipientKeyIdentifier
      extends ASN1Object

  RFC 5652: Content encryption key delivery mechanisms.

       RecipientKeyIdentifier ::= SEQUENCE {
           subjectKeyIdentifier SubjectKeyIdentifier,
           date GeneralizedTime OPTIONAL,
           other OtherKeyAttribute OPTIONAL
       }

       SubjectKeyIdentifier ::= OCTET STRING

- - ### Constructor Summary

    Constructors
    Constructor and Description
    `RecipientKeyIdentifier(ASN1OctetString subjectKeyIdentifier, ASN1GeneralizedTime date, OtherKeyAttribute other)`
    `RecipientKeyIdentifier(byte[] subjectKeyIdentifier)`
    `RecipientKeyIdentifier(byte[] subjectKeyIdentifier, ASN1GeneralizedTime date, OtherKeyAttribute other)`

  - ### Method Summary

    All Methods Static Methods Instance Methods Concrete Methods
    Modifier and Type | Method and Description
    --- | ---
    `ASN1GeneralizedTime` | `getDate()`
    `static RecipientKeyIdentifier` | `getInstance(ASN1TaggedObject ato, boolean isExplicit)` Return a RecipientKeyIdentifier object from a tagged object.
    `static RecipientKeyIdentifier` | `getInstance(java.lang.Object obj)` Return a RecipientKeyIdentifier object from the given object.
    `OtherKeyAttribute` | `getOtherKeyAttribute()`
    `ASN1OctetString` | `getSubjectKeyIdentifier()`
    `ASN1Primitive` | `toASN1Primitive()` Produce an object suitable for an ASN1OutputStream.

    - ### Methods inherited from class org.bouncycastle.asn1.ASN1Object

      `encodeTo, encodeTo, equals, getEncoded, getEncoded, hasEncodedTagValue, hashCode`

    - ### Methods inherited from class java.lang.Object

      `clone, finalize, getClass, notify, notifyAll, toString, wait, wait, wait`

- - ### Constructor Detail

    - #### RecipientKeyIdentifier

          public RecipientKeyIdentifier(ASN1OctetString subjectKeyIdentifier,
                                        ASN1GeneralizedTime date,
                                        OtherKeyAttribute other)

    - #### RecipientKeyIdentifier

          public RecipientKeyIdentifier(byte[] subjectKeyIdentifier,
                                        ASN1GeneralizedTime date,
                                        OtherKeyAttribute other)

    - #### RecipientKeyIdentifier

          public RecipientKeyIdentifier(byte[] subjectKeyIdentifier)

  - ### Method Detail

    - #### getInstance

          public static RecipientKeyIdentifier getInstance(ASN1TaggedObject ato,
                                                           boolean isExplicit)

      Return a RecipientKeyIdentifier object from a tagged object.
      Parameters:
        `ato` - the tagged object holding the object we want.
        `isExplicit` - true if the object is meant to be explicitly tagged false otherwise.
      Throws:
        `java.lang.IllegalArgumentException` - if the object held by the tagged object cannot be converted.

    - #### getInstance

          public static RecipientKeyIdentifier getInstance(java.lang.Object obj)

      Return a RecipientKeyIdentifier object from the given object.

      Accepted inputs:

      - null → null
      - `RecipientKeyIdentifier` object
      - `ASN1Sequence` input formats with RecipientKeyIdentifier structure inside
      Parameters:
        `obj` - the object we want converted.
      Throws:
        `java.lang.IllegalArgumentException` - if the object cannot be converted.

    - #### getSubjectKeyIdentifier

          public ASN1OctetString getSubjectKeyIdentifier()

    - #### getDate

          public ASN1GeneralizedTime getDate()

    - #### getOtherKeyAttribute

          public OtherKeyAttribute getOtherKeyAttribute()

    - #### toASN1Primitive

          public ASN1Primitive toASN1Primitive()

      Produce an object suitable for an ASN1OutputStream.
      Specified by:
        `toASN1Primitive` in interface `ASN1Encodable`
      Specified by:
        `toASN1Primitive` in class `ASN1Object`
      Returns:
        a primitive representation of this object.