Package com.nimbusds.jose.crypto

Class DirectDecrypter

java.lang.Object

com.nimbusds.jose.crypto.impl.BaseJWEProvider

com.nimbusds.jose.crypto.impl.DirectCryptoProvider

com.nimbusds.jose.crypto.DirectDecrypter

All Implemented Interfaces:

CriticalHeaderParamsAware, JCAAware<JWEJCAContext>, JOSEProvider, JWEDecrypter, JWEProvider

@ThreadSafe
public class DirectDecrypter
extends DirectCryptoProvider
implements JWEDecrypter, CriticalHeaderParamsAware

Direct decrypter of JWE objects with a shared symmetric key.

See RFC 7518 section 4.5 for more information.

This class is thread-safe.

Supports the following key management algorithms:

• JWEAlgorithm.DIR

Supports the following content encryption algorithms:

• EncryptionMethod.A128CBC_HS256 (requires 256 bit key)
• EncryptionMethod.A192CBC_HS384 (requires 384 bit key)
• EncryptionMethod.A256CBC_HS512 (requires 512 bit key)
• EncryptionMethod.A128GCM (requires 128 bit key)
• EncryptionMethod.A192GCM (requires 192 bit key)
• EncryptionMethod.A256GCM (requires 256 bit key)
• EncryptionMethod.A128CBC_HS256_DEPRECATED (requires 256 bit key)
• EncryptionMethod.A256CBC_HS512_DEPRECATED (requires 512 bit key)
• EncryptionMethod.XC20P (requires 256 bit key)

Also supports a promiscuous mode to decrypt any JWE by passing the content encryption key (CEK) directly. The that mode the JWE algorithm checks for ("alg":"dir") and encrypted key not being present will be skipped.

Version:

2023-09-10

Author:

Vladimir Dzhuvinov, Egor Puzanov

Field Summary

Fields inherited from class com.nimbusds.jose.crypto.impl.DirectCryptoProvider

SUPPORTED_ALGORITHMS, SUPPORTED_ENCRYPTION_METHODS

Constructor Summary

Constructors

Constructor	Description
DirectDecrypter(byte[] keyBytes)	Creates a new direct decrypter.
DirectDecrypter(OctetSequenceKey octJWK)	Creates a new direct decrypter.
DirectDecrypter(SecretKey key)	Creates a new direct decrypter.
DirectDecrypter(SecretKey key, boolean promiscuousMode)	Creates a new direct decrypter with the option to set it in promiscuous mode.
DirectDecrypter(SecretKey key, Set<String> defCritHeaders)	Creates a new direct decrypter with the option to set it in promiscuous mode.
DirectDecrypter(SecretKey key, Set<String> defCritHeaders, boolean promiscuousMode)	Creates a new direct decrypter.

Method Summary

Modifier and Type	Method	Description
byte[]	decrypt(JWEHeader header, Base64URL encryptedKey, Base64URL iv, Base64URL cipherText, Base64URL authTag)	Deprecated.
byte[]	decrypt(JWEHeader header, Base64URL encryptedKey, Base64URL iv, Base64URL cipherText, Base64URL authTag, byte[] aad)	Decrypts the specified cipher text of a JWE Object.
Set<String>	getDeferredCriticalHeaderParams()	Returns the names of the critical (crit) header parameters that are deferred to the application for processing and will be ignored by the JWS verifier / JWE decrypter.
Set<String>	getProcessedCriticalHeaderParams()	Returns the names of the critical (crit) header parameters that are understood and processed by the JWS verifier / JWE decrypter.

Methods inherited from class com.nimbusds.jose.crypto.impl.DirectCryptoProvider

getKey

Methods inherited from class com.nimbusds.jose.crypto.impl.BaseJWEProvider

getCEK, getJCAContext, isCEKProvided, supportedEncryptionMethods, supportedJWEAlgorithms

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Methods inherited from interface com.nimbusds.jose.jca.JCAAware

getJCAContext

Methods inherited from interface com.nimbusds.jose.JWEProvider

supportedEncryptionMethods, supportedJWEAlgorithms

Constructor Details

DirectDecrypter

public DirectDecrypter(SecretKey key)
                throws KeyLengthException

Creates a new direct decrypter.

Parameters:

key - The symmetric key. Its algorithm should be "AES". Must be 128 bits (16 bytes), 192 bits (24 bytes), 256 bits (32 bytes), 384 bits (48 bytes) or 512 bits (64 bytes) long. Must not be null.

Throws:

KeyLengthException - If the symmetric key length is not compatible.

DirectDecrypter

public DirectDecrypter(SecretKey key,
 boolean promiscuousMode)
                throws KeyLengthException

Creates a new direct decrypter with the option to set it in promiscuous mode.

Parameters:

key - The symmetric key. Its algorithm should be "AES". Must be 128 bits (16 bytes), 192 bits (24 bytes), 256 bits (32 bytes), 384 bits (48 bytes) or 512 bits (64 bytes) long. Must not be null.

promiscuousMode - If true set the decrypter in promiscuous mode to permit decryption of any JWE with the supplied symmetric key. The that mode the JWE algorithm checks for ("alg":"dir") and encrypted key not being present will be skipped.

Throws:

KeyLengthException - If the symmetric key length is not compatible.

DirectDecrypter

public DirectDecrypter(byte[] keyBytes)
                throws KeyLengthException

Creates a new direct decrypter.

Parameters:

keyBytes - The symmetric key, as a byte array. Must be 128 bits (16 bytes), 192 bits (24 bytes), 256 bits (32 bytes), 384 bits (48 bytes) or 512 bits (64 bytes) long. Must not be null.

Throws:

KeyLengthException - If the symmetric key length is not compatible.

DirectDecrypter

public DirectDecrypter(OctetSequenceKey octJWK)
                throws KeyLengthException

Creates a new direct decrypter.

Parameters:

octJWK - The symmetric key, as a JWK. Must be 128 bits (16 bytes), 192 bits (24 bytes), 256 bits (32 bytes), 384 bits (48 bytes) or 512 bits (64 bytes) long. Must not be null.

Throws:

KeyLengthException - If the symmetric key length is not compatible.

DirectDecrypter

public DirectDecrypter(SecretKey key,
 Set<String> defCritHeaders)
                throws KeyLengthException

Creates a new direct decrypter with the option to set it in promiscuous mode.

Parameters:

key - The symmetric key. Its algorithm should be "AES". Must be 128 bits (16 bytes), 192 bits (24 bytes), 256 bits (32 bytes), 384 bits (48 bytes) or 512 bits (64 bytes) long. Must not be null.

defCritHeaders - The names of the critical header parameters that are deferred to the application for processing, empty set or null if none.

Throws:

KeyLengthException - If the symmetric key length is not compatible.

DirectDecrypter

public DirectDecrypter(SecretKey key,
 Set<String> defCritHeaders,
 boolean promiscuousMode)
                throws KeyLengthException

Creates a new direct decrypter.

Parameters:

key - The symmetric key. Its algorithm should be "AES". Must be 128 bits (16 bytes), 192 bits (24 bytes), 256 bits (32 bytes), 384 bits (48 bytes) or 512 bits (64 bytes) long. Must not be null.

defCritHeaders - The names of the critical header parameters that are deferred to the application for processing, empty set or null if none.

promiscuousMode - If true set the decrypter in promiscuous mode to permit decryption of any JWE with the supplied symmetric key. The that mode the JWE algorithm checks for ("alg":"dir") and encrypted key not being present will be skipped.

Throws:

KeyLengthException - If the symmetric key length is not compatible.

Method Details

getProcessedCriticalHeaderParams

public Set<String> getProcessedCriticalHeaderParams()

Description copied from interface: CriticalHeaderParamsAware

Returns the names of the critical (crit) header parameters that are understood and processed by the JWS verifier / JWE decrypter.

Specified by:

getProcessedCriticalHeaderParams in interface CriticalHeaderParamsAware

Returns:

The names of the critical header parameters that are understood and processed, empty set if none.

getDeferredCriticalHeaderParams

public Set<String> getDeferredCriticalHeaderParams()

Description copied from interface: CriticalHeaderParamsAware

Returns the names of the critical (crit) header parameters that are deferred to the application for processing and will be ignored by the JWS verifier / JWE decrypter.

Specified by:

getDeferredCriticalHeaderParams in interface CriticalHeaderParamsAware

Returns:

The names of the critical header parameters that are deferred to the application for processing, empty set if none.

decrypt

@Deprecated
public byte[] decrypt(JWEHeader header,
 Base64URL encryptedKey,
 Base64URL iv,
 Base64URL cipherText,
 Base64URL authTag)
               throws JOSEException

Deprecated.

Decrypts the specified cipher text of a JWE Object.

Parameters:

header - The JSON Web Encryption (JWE) header. Must specify a supported JWE algorithm and method. Must not be null.

encryptedKey - The encrypted key, null if not required by the JWE algorithm.

iv - The initialisation vector, null if not required by the JWE algorithm.

cipherText - The cipher text to decrypt. Must not be null.

authTag - The authentication tag, null if not required.

Returns:

The clear text.

Throws:

JOSEException - If the JWE algorithm or method is not supported, if a critical header parameter is not supported or marked for deferral to the application, or if decryption failed for some other reason.

decrypt

public byte[] decrypt(JWEHeader header,
 Base64URL encryptedKey,
 Base64URL iv,
 Base64URL cipherText,
 Base64URL authTag,
 byte[] aad)
               throws JOSEException

Description copied from interface: JWEDecrypter

Decrypts the specified cipher text of a JWE Object.

Specified by:

decrypt in interface JWEDecrypter

Parameters:

header - The JSON Web Encryption (JWE) header. Must specify a supported JWE algorithm and method. Must not be null.

encryptedKey - The encrypted key, null if not required by the JWE algorithm.

iv - The initialisation vector, null if not required by the JWE algorithm.

cipherText - The cipher text to decrypt. Must not be null.

authTag - The authentication tag, null if not required.

aad - The additional authenticated data. Must not be null.

Returns:

The clear text.

Throws:

JOSEException - If the JWE algorithm or method is not supported, if a critical header parameter is not supported or marked for deferral to the application, or if decryption failed for some other reason.