Struct CollectionItem 

pub struct CollectionItem {
    pub iv: u32,
    pub ciphertext_and_tag: Vec<u8>,
}

Collection item containing an encrypted payload with its IV

Each item uses a unique counter-based IV derived from the collection’s IV counter. The ciphertext_and_tag contains the AES-GCM encrypted data with the authentication tag appended.

Fields

iv: u32

24-bit IV counter value (1 to MAX_IV) This is used to reconstruct the 12-byte GCM nonce: [9 zeros][3-byte IV]

ciphertext_and_tag: Vec<u8>

Ciphertext with authentication tag appended Format: [encrypted_data][auth_tag] Tag size depends on the symmetric cipher config in the collection manifest

Implementations

impl CollectionItem

pub fn new(iv: u32, ciphertext_and_tag: Vec<u8>) -> Self

Create a new collection item

pub fn to_bytes(&self) -> Vec<u8>

Container framing: [IV (3B)][ciphertext][tag]

Use this format when the container (FLV/RTMP) provides the length. This is the minimal wire format for streaming scenarios.

pub fn to_nanotdf_payload_bytes(&self) -> Vec<u8>

NanoTDF payload framing: [length (3B)][IV (3B)][ciphertext][tag]

This is spec-compliant format with a 3-byte length prefix. Use this when you need a self-describing payload format.

pub fn from_bytes(bytes: &[u8]) -> Result<Self>

Parse from container framing: [IV (3B)][ciphertext][tag]

The caller must know the total length from the container.

pub fn from_nanotdf_payload_bytes(bytes: &[u8]) -> Result<Self>

Parse from NanoTDF payload framing: [length (3B)][IV (3B)][ciphertext][tag]

Reads the length prefix and validates the payload size.

pub fn read_from<R: Read>(reader: &mut R, total_len: usize) -> Result<Self>

Read from a reader using container framing

Reads exactly total_len bytes (IV + ciphertext + tag).

pub fn read_nanotdf_payload_from<R: Read>(reader: &mut R) -> Result<Self>

Read from a reader using NanoTDF payload framing

Reads the length prefix first, then the payload.

pub fn write_to<W: Write>(&self, writer: &mut W) -> Result<()>

Write to a writer using container framing

pub fn write_nanotdf_payload_to<W: Write>(&self, writer: &mut W) -> Result<()>

Write to a writer using NanoTDF payload framing

pub fn container_size(&self) -> usize

Get the total size in container framing format

pub fn nanotdf_payload_size(&self) -> usize

Get the total size in NanoTDF payload framing format

pub fn iv_bytes(&self) -> [u8; 3]

Convert the IV counter to a 3-byte array

pub fn to_gcm_nonce(&self) -> [u8; 12]

Convert the IV to a 12-byte GCM nonce

Per NanoTDF spec and JS SDK interop: [9 zero bytes][3-byte IV counter]

Trait Implementations

impl Clone for CollectionItem

fn clone(&self) -> Self

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for CollectionItem

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Eq for CollectionItem

impl PartialEq for CollectionItem

fn eq(&self, other: &Self) -> bool

Equality operator ==.

fn ne(&self, other: &Rhs) -> bool

Inequality operator !=.

impl StructuralPartialEq for CollectionItem