Struct ImageVerifier 

pub struct ImageVerifier { /* private fields */ }

Hashes an image as it arrives and checks it against a manifest.

Examples

use pamoja_update::{ImageVerifier, Manifest, PayloadFormat, STRUCTURE_VERSION};
use sha2::{Digest, Sha256};

let image = b"firmware bytes";
let manifest = Manifest {
    structure_version: STRUCTURE_VERSION,
    sequence: 1,
    vendor_id: [0; 16],
    class_id: [0; 16],
    format: PayloadFormat::Raw,
    storage: 0,
    digest: Sha256::digest(image).into(),
    size: image.len() as u32,
    expires: 0,
};

let mut verifier = ImageVerifier::new(&manifest);
for chunk in image.chunks(4) {
    verifier.update(chunk).unwrap();
}
assert!(verifier.finish().is_ok());

Implementations

impl ImageVerifier

pub fn new(manifest: &Manifest) -> Self

Starts verifying an image against manifest.

Arguments

• manifest - the manifest whose digest and size the image must match.

Returns

A verifier awaiting the image.

pub fn update(&mut self, chunk: &[u8]) -> Result<()>

Folds the next chunk of the image in.

Arguments

• chunk - the next bytes of the image, in order.

Returns

Ok(()) once the chunk is hashed.

Errors

Returns Refusal::Size as soon as more bytes arrive than the manifest declared, so an oversized payload is stopped while it is arriving rather than after it has filled the slot.

pub fn finish(self) -> Result<Verified>

Finishes the check and reports whether the image is the one described.

Returns

A Verified receipt when the image is exactly the length and content the manifest committed to.

Errors

Returns Refusal::Size if fewer bytes arrived than declared, or Refusal::Digest if the content does not hash to the manifest’s digest.