See Message Version.
The message body AAD is the serialization of the AAD to be used as input to encryption of the message body.
The following describes the fields that form the message body AAD. The bytes are appended in the order shown.
| Field | Length (bytes) | Interpreted as |
|---|---|---|
| Message ID | 16 | Bytes |
| Body AAD Content | Variable. | UTF-8 Bytes |
| Sequence Number | 4 | Uint32 |
| Content Length | 8 | Uint64 |
An identifier for the message this message body AAD is associated with.
An identifier for the content type of the data this message body AAD is associated with.
This value depends on the content type of the message:
- Non-framed data MUST use the value
AWSKMSEncryptionClient Single Block. - The regular frames in framed data MUST use the value
AWSKMSEncryptionClient Frame. - The final frame in framed data MUST use the value
AWSKMSEncryptionClient Final Frame.
The sequence number of the data this message body AAD belongs to.
For framed data, the value of this field MUST be the frame sequence number.
For non-framed data, the value of this field MUST be 1.
The length, in bytes, of the plaintext data being encrypted that this message body AAD is associated with.
More specifically, depending on the content type of the message:
- For non-framed data, this value MUST equal the length, in bytes, of the plaintext data provided to the algorithm for encryption.
- For framed data, this value MUST equal the length, in bytes,
of the plaintext being encrypted in this frame.
- For regular frames, this value MUST equal the value of the frame length field in the message header.
- For the final frame, this value MUST be greater than or equal to 0 and less than or equal to the value of the frame length field in the message header.