f4118f28ba
Updated Reserved entry order. Made DataType ID changes easier in future (this MAY NOT happen again once in use).
38 lines
980 B
Rust
38 lines
980 B
Rust
use crate::error::CryptoError;
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use hkdf::Hkdf;
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use sha2::Sha256;
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pub fn hkdf_expand(
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ikm: &[u8],
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salt: &[u8],
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info: &[u8],
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okm_len: usize,
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) -> Result<Vec<u8>, CryptoError> {
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let hk = Hkdf::<Sha256>::new(Some(salt), ikm);
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let mut okm = vec![0u8; okm_len];
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hk.expand(info, &mut okm)
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.map_err(|_| CryptoError::KdfError)?;
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Ok(okm)
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}
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pub fn hkdf_extract(ikm: &[u8], salt: &[u8]) -> [u8; 32] {
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/*
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* Return the pseudo-random key (PRK) produced by HKDF-Extract directly.
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* Extract cannot fail, so this avoids the panicking expand step entirely.
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*/
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let (prk, _) = Hkdf::<Sha256>::extract(Some(salt), ikm);
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let mut out = [0u8; 32];
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out.copy_from_slice(&prk);
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out
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}
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pub fn derive_encryption_key(
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ikm: &[u8],
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salt: &[u8],
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context: &[u8],
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) -> Result<[u8; 32], CryptoError> {
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let key = hkdf_expand(ikm, salt, context, 32)?;
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let mut out = [0u8; 32];
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out.copy_from_slice(&key);
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Ok(out)
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}
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