Class AesSpec.Builder

java.lang.Object

zeroecho.core.alg.aes.AesSpec.Builder

Enclosing class:

AesSpec

public static final class AesSpec.Builder
extends Object

Builder for AesSpec.

Not thread‑safe. The resulting AesSpec is immutable.

Since:

1.0

Constructor Summary

Constructors

Constructor	Description
Builder()	Creates a builder initialized for AES-GCM with a 128-bit tag.

Method Summary

Modifier and Type	Method	Description
AesSpec	build()	Builds a validated AesSpec.
AesSpec.Builder	header(SymmetricHeaderCodec codec)	Installs a header codec used by the cipher context to persist and recover runtime parameters (e.g., IV, tag length, AAD hash).
AesSpec.Builder	mode(AesSpec.Mode m)	Selects the AES mode.
AesSpec.Builder	padding(AesSpec.Padding p)	Selects the padding scheme for CBC.
AesSpec.Builder	tagLenBits(int t)	Sets the GCM authentication tag length in bits.

Methods inherited from class Object

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

Constructor Details

Builder

public Builder()

Creates a builder initialized for AES-GCM with a 128-bit tag.

Method Details

mode

public AesSpec.Builder mode(AesSpec.Mode m)

Selects the AES mode.

Parameters:

m - the block mode (AesSpec.Mode.CBC, AesSpec.Mode.GCM, or AesSpec.Mode.CTR)

Returns:

this builder

Throws:

NullPointerException - if m is null

padding

public AesSpec.Builder padding(AesSpec.Padding p)

Selects the padding scheme for CBC.

Ignored for GCM and CTR, which always use AesSpec.Padding.NOPADDING.

Parameters:

p - the padding scheme

Returns:

this builder

Throws:

NullPointerException - if p is null

tagLenBits

public AesSpec.Builder tagLenBits(int t)

Sets the GCM authentication tag length in bits.

Valid only when the mode is AesSpec.Mode.GCM. The value must be 96, 104, 112, 120, or 128.

Parameters:

t - the tag length in bits

Returns:

this builder

header

public AesSpec.Builder header(SymmetricHeaderCodec codec)

Installs a header codec used by the cipher context to persist and recover runtime parameters (e.g., IV, tag length, AAD hash).

When null, no header is written or parsed.

Parameters:

codec - the codec to embed, or null to disable

Returns:

this builder

build

public AesSpec build()

Builds a validated AesSpec.

Validation rules:

• If mode is AesSpec.Mode.GCM, padding must be AesSpec.Padding.NOPADDING and tagLenBits must be 96–128 in steps of 8.
• If mode is not GCM, tagLenBits must be 0.

Returns:

an immutable specification

Throws:

IllegalArgumentException - if parameters are inconsistent