sourceKeyId

Specifies the KMS key that KMS will use to decrypt the ciphertext before it is re-encrypted.

Enter a key ID of the KMS key that was used to encrypt the ciphertext. If you identify a different KMS key, the ReEncrypt operation throws an IncorrectKeyException.

This parameter is required only when the ciphertext was encrypted under an asymmetric KMS key or when DryRun is true and DryRunModifiers is set to IGNORE_CIPHERTEXT. If you used a symmetric encryption KMS key, KMS can get the KMS key from metadata that it adds to the symmetric ciphertext blob. However, it is always recommended as a best practice. This practice ensures that you use the KMS key that you intend.

To specify a KMS key, use its key ID, key ARN, alias name, or alias ARN. When using an alias name, prefix it with "alias/". To specify a KMS key in a different Amazon Web Services account, you must use the key ARN or alias ARN.

For example:

• Key ID: 1234abcd-12ab-34cd-56ef-1234567890ab

• Key ARN: arn:aws:kms:us-east-2:111122223333:key/1234abcd-12ab-34cd-56ef-1234567890ab

• Alias name: alias/ExampleAlias

• Alias ARN: arn:aws:kms:us-east-2:111122223333:alias/ExampleAlias

To get the key ID and key ARN for a KMS key, use ListKeys or DescribeKey. To get the alias name and alias ARN, use ListAliases.