Trait rustls::crypto::tls13::HkdfExpander

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pub trait HkdfExpander: Send + Sync {
    // Required methods
    fn expand_slice(
        &self,
        info: &[&[u8]],
        output: &mut [u8],
    ) -> Result<(), OutputLengthError>;
    fn expand_block(&self, info: &[&[u8]]) -> OkmBlock;
    fn hash_len(&self) -> usize;
}
Expand description

Implementation of HKDF-Expand with an implicitly stored and immutable PRK.

Required Methods§

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fn expand_slice( &self, info: &[&[u8]], output: &mut [u8], ) -> Result<(), OutputLengthError>

HKDF-Expand(PRK, info, L) into a slice.

Where:

  • PRK is the implicit key material represented by this instance.
  • L is output.len().
  • info is a slice of byte slices, which should be processed sequentially (or concatenated if that is not possible).

Returns Err(OutputLengthError) if L is larger than 255 * HashLen. Otherwise, writes to output.

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fn expand_block(&self, info: &[&[u8]]) -> OkmBlock

HKDF-Expand(PRK, info, L=HashLen) returned as a value.

  • PRK is the implicit key material represented by this instance.
  • L := HashLen.
  • info is a slice of byte slices, which should be processed sequentially (or concatenated if that is not possible).

This is infallible, because by definition OkmBlock is always exactly HashLen bytes long.

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fn hash_len(&self) -> usize

Return what HashLen is for this instance.

This must be no larger than OkmBlock::MAX_LEN.

Implementors§