- java.lang.Object
- 
- javax.crypto.spec.GCMParameterSpec
 
- 
- All Implemented Interfaces:
- AlgorithmParameterSpec
 
 public class GCMParameterSpec extends Object implements AlgorithmParameterSpec Specifies the set of parameters required by aCipherusing the Galois/Counter Mode (GCM) mode.Simple block cipher modes (such as CBC) generally require only an initialization vector (such as IvParameterSpec), but GCM needs these parameters:- IV: Initialization Vector (IV)
- tLen: length (in bits) of authentication tag T
 In addition to the parameters described here, other GCM inputs/output (Additional Authenticated Data (AAD), Keys, block ciphers, plain/ciphertext and authentication tags) are handled in the Cipherclass.Please see RFC 5116 for more information on the Authenticated Encryption with Associated Data (AEAD) algorithm, and NIST Special Publication 800-38D, "NIST Recommendation for Block Cipher Modes of Operation: Galois/Counter Mode (GCM) and GMAC." The GCM specification states that tLenmay only have the values {128, 120, 112, 104, 96}, or {64, 32} for certain applications. Other values can be specified for this class, but not all CSP implementations will support them.- Since:
- 1.7
- See Also:
- Cipher
 
- 
- 
Constructor SummaryConstructors Constructor Description GCMParameterSpec(int tLen, byte[] src)Constructs a GCMParameterSpec using the specified authentication tag bit-length and IV buffer.GCMParameterSpec(int tLen, byte[] src, int offset, int len)Constructs a GCMParameterSpec object using the specified authentication tag bit-length and a subset of the specified buffer as the IV.
 - 
Method SummaryAll Methods Instance Methods Concrete Methods Modifier and Type Method Description byte[]getIV()Returns the Initialization Vector (IV).intgetTLen()Returns the authentication tag length.
 
- 
- 
- 
Constructor Detail- 
GCMParameterSpecpublic GCMParameterSpec(int tLen, byte[] src)Constructs a GCMParameterSpec using the specified authentication tag bit-length and IV buffer.- Parameters:
- tLen- the authentication tag length (in bits)
- src- the IV source buffer. The contents of the buffer are copied to protect against subsequent modification.
- Throws:
- IllegalArgumentException- if- tLenis negative, or- srcis null.
 
 - 
GCMParameterSpecpublic GCMParameterSpec(int tLen, byte[] src, int offset, int len)Constructs a GCMParameterSpec object using the specified authentication tag bit-length and a subset of the specified buffer as the IV.- Parameters:
- tLen- the authentication tag length (in bits)
- src- the IV source buffer. The contents of the buffer are copied to protect against subsequent modification.
- offset- the offset in- srcwhere the IV starts
- len- the number of IV bytes
- Throws:
- IllegalArgumentException- if- tLenis negative,- srcis null,- lenor- offsetis negative, or the sum of- offsetand- lenis greater than the length of the- srcbyte array.
 
 
- 
 
-