Struct FST

pub struct FST {
    pub enc_algo: Option<EncryptionAlgo>,
    pub hash_algo: Option<HashAlgo>,
    pub partition_size: u32,
    /* private fields */
}

Firmware Security Table (FST)

The FST struct represents the firmware security table (FST) of a sub-image within a firmware image. This table holds information about the encryption algorithm, hash algorithm, security keys, and other configuration for firmware partitions.

Layout

         +-------+-------+--------+-------+-----------+---------------+---+---+---+---+----+----+----+----+----+----+
         | 0     | 1     | 2      | 3     | 4         | 5             | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 |
+========+=======+=======+========+=======+===========+===============+===+===+===+===+====+====+====+====+====+====+
| 0x00   | enc_algo: u16 | hash_algo: u16 |          part_size: u32           |          valipat: bytes[8]          |
+--------+--------------------------------+-----------+---------------+---------------------------------------------+
| 0x10   |                                | flags: u8 | key_flags: u8 |                                             |
+--------+--------------------------------+-----------+---------------+---------------------------------------------+
| 0x20   |                                          cipher_key: bytes[32]                                           |
+--------+----------------------------------------------------------------------------------------------------------+
| 0x40   |                                           cipher_iv: bytes[16]                                           |
+--------+----------------------------------------------------------------------------------------------------------+
| 0x50   |                                                                                                          |
+--------+----------------------------------------------------------------------------------------------------------+

• Size = 0x60 = 96 bytes

Note: Encryption and cipher-related fields are placeholders, as encryption is not currently supported. These fields are implemented as Option<T> to allow future extension if encryption support is added later.

Example:

let mut fst = FST::default();

// set hash algorithm
fst.hash_algo = Some(HashAlgo::Sha256);

// clear encryption algorithm
fst.enc_algo = None;

Fields

enc_algo: Option<EncryptionAlgo>

encryption algorithm (not supported)

hash_algo: Option<HashAlgo>

The hash algorithm used for hashing. Default is Sha256.

partition_size: u32

Implementations

impl FST

pub fn is_cipher_key_iv_valid(&self) -> bool

Checks if the cipher key and IV are valid.

Returns:

• true: If both the cipher key and IV are valid.
• false: If either the cipher key or IV is not set or invalid.

pub fn get_pattern(&self) -> &[u8; 8]

Returns a reference to the validation pattern used for the FST structure.

Returns:

A reference to the 8-byte validation pattern.

pub fn get_cipher_key(&self) -> DataRefType<'_, 32>

Returns a reference to the cipher key if it is set.

Returns:

An Option containing a reference to the 32-byte cipher key.

let fst = FST::default();
if let Some(cipher_key) = fst.get_cipher_key() {
    // Handle valid cipher key
}

pub fn get_cipher_iv(&self) -> DataRefType<'_, 16>

Returns a reference to the cipher IV if it is set.

Returns:

An Option containing a reference to the 16-byte cipher IV.

pub fn set_cipher_iv(&mut self, iv: DataType<16>)

pub fn set_cipher_key(&mut self, key: DataType<32>)

pub fn set_valid_pattern(&mut self, pattern: [u8; 8])

Trait Implementations

impl BinarySize for FST

fn binary_size() -> usize

Returns the binary size of the FST structure in bytes.

Returns:

The size of the FST struct in bytes, which is 0x60 (96 bytes).

impl Debug for FST

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

Formats the value using the given formatter.

impl Default for FST

fn default() -> FST

Returns the “default value” for a type.

impl FromStream for FST

fn read_from<R>(&mut self, reader: &mut R) -> Result<(), Error>

where R: Read + Seek,

Reads the FST structure from a stream and parses its data.

Parameters:

• reader: A mutable reference to a reader that implements std::io::Read and std::io::Seek traits. This could be a file, buffer, or network stream.

Returns:

• On failure, an Error is returned.

impl ToStream for FST

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

where W: Write,

Writes the FST structure to a stream

Parameters:

• writer: A mutable reference to a writer that implements the std::io::Write trait. This could be a file, buffer, or network stream where the FST will be written.