GcmContextBuilder

Provides support for building GCM (Galois/Counter Mode) cipher contexts.

Extends

• CipherContextBuilder

Accessors

additionalData

Set Signature

set additionalData(data): void

Specify additional authentication data (AAD) to be included in the GCM context.

Remarks

This parameter is optional.

Parameters

data

ArrayBuffer

The additional data to include.

Returns

void

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iv

Set Signature

set iv(iv): void

Specify the initialization vector (IV) to use. Use a 4-byte array when intending to use a randomized sequence of nonces (the IV is used as an identifier to differentiate the sequence). Otherwise, set it with an array of length equal to the value returned by the ivSize() API (in that case the IV is used as an arbitrary nonce).

Remarks

This parameter is mandatory.

Parameters

iv

ArrayBuffer

The initialization vector to use.

Returns

void

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ivSize

Get Signature

get ivSize(): number

Get the size of the initialization vector (IV) for the GCM cipher when used as an arbitrary nonce.

Returns

number

The size of the IV in bytes.

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key

Set Signature

set key(key): void

Specify the symmetric key to be used for encryption or decryption.

Remarks

This parameter is mandatory.

Parameters

key

SymmetricKey

The symmetric key to use.

Returns

void

Inherited from

CipherContextBuilder.key

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tagLength

Set Signature

set tagLength(length): void

Specify the desired length of the authentication tag.

Remarks

This parameter is optional.

Parameters

length

number

The length of the authentication tag in bits.

Returns

void

Methods

buildDecryptionContext()

buildDecryptionContext(): DecryptionContext

Build a context that can be used for decryption operations.

Returns

DecryptionContext

A decryption context.

Throws

AccessDeniedError If the key lacks the KeyPurpose.DECRYPT purpose.

Throws

InvalidArgumentError If any mandatory parameter is missing or the key is invalid.

Inherited from

CipherContextBuilder.buildDecryptionContext

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buildEncryptionContext()

buildEncryptionContext(): EncryptionContext

Build a context that can be used for encryption operations.

Returns

EncryptionContext

An encryption context.

Throws

AccessDeniedError If the key lacks the KeyPurpose.ENCRYPT purpose.

Throws

InvalidArgumentError If any mandatory parameter is missing or the key is invalid.

Inherited from

CipherContextBuilder.buildEncryptionContext

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buildWrappingContext()

buildWrappingContext(scheme): WrappingContext

Build a context that can be used for wrapping keys.

Parameters

scheme

WrappingScheme

The wrapping scheme to be used.

Returns

WrappingContext

A wrapping context.

Throws

AccessDeniedError If the key lacks the KeyPurpose.WRAP and KeyPurpose.UNWRAP purposes.

Throws

InvalidArgumentError If any mandatory parameter is missing or the key is invalid.

Throws

NotSupportedError If the implementation does not support wrapping operations.

Inherited from

CipherContextBuilder.buildWrappingContext

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Last updated: Sep 30, 2025