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

org.bouncycastle.asn1.cms

## Class RsaKemParameters

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

- All Implemented Interfaces:
    ASN1Encodable, Encodable

      public class RsaKemParameters
      extends ASN1Object

  RFC 5990 RSA KEM parameters class.

        RsaKemParameters ::= SEQUENCE {
           keyDerivationFunction  KeyDerivationFunction,
           keyLength              KeyLength
         }

         KeyDerivationFunction ::= AlgorithmIdentifier
         KeyLength ::= INTEGER (1..MAX)

- - ### Constructor Summary

    Constructors
    Constructor and Description
    `RsaKemParameters(AlgorithmIdentifier keyDerivationFunction, int keyLength)` Base constructor.

  - ### Method Summary

    All Methods Static Methods Instance Methods Concrete Methods
    Modifier and Type | Method and Description
    --- | ---
    `static RsaKemParameters` | `getInstance(java.lang.Object o)`
    `AlgorithmIdentifier` | `getKeyDerivationFunction()`
    `java.math.BigInteger` | `getKeyLength()`
    `ASN1Primitive` | `toASN1Primitive()` Method providing a primitive representation of this object suitable for encoding.

    - ### 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

    - #### RsaKemParameters

          public RsaKemParameters(AlgorithmIdentifier keyDerivationFunction,
                                  int keyLength)

      Base constructor.
      Parameters:
        `keyDerivationFunction` - algorithm ID describing the key derivation function.
        `keyLength` - length of key to be derived (in bytes).

  - ### Method Detail

    - #### getInstance

          public static RsaKemParameters getInstance(java.lang.Object o)

    - #### getKeyDerivationFunction

          public AlgorithmIdentifier getKeyDerivationFunction()

    - #### getKeyLength

          public java.math.BigInteger getKeyLength()

    - #### toASN1Primitive

          public ASN1Primitive toASN1Primitive()

      Description copied from class: `ASN1Object`
      Method providing a primitive representation of this object suitable for encoding.
      Specified by:
        `toASN1Primitive` in interface `ASN1Encodable`
      Specified by:
        `toASN1Primitive` in class `ASN1Object`
      Returns:
        a primitive representation of this object.