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prepare_from

polymorph_webcrypto_guest::hkdf_sha2

Function prepare_from 

Source 
pub async fn prepare_from(
    variant: Sha2Variant,
    input: &DeriveInput,
    salt: impl Into<Vec<u8>>,
    info: impl Into<Vec<u8>>,
) -> Result<DeriveInput, Error>
Expand description

Parameterize an HKDF derivation over another derivation’s output — the chaining step, e.g. from an AgreementSecretKey::agree (WebCrypto’s deriveKey(ECDH → HKDF) shape).

The upstream derivation runs at its natural output length, so only sources that have one chain: an agreement’s shared secret does; KDF sources fail Error::Other, as the platform does. Requires the upstream input’s derive_key grant.