| // Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or |
| // http://www.apache.org/licenses/LICENSE-2.0> or the MIT license |
| // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your |
| // option. This file may not be copied, modified, or distributed |
| // except according to those terms. |
| |
| //! This module implements the HMAC-based Extract-and-Expand Key |
| //! Derivation Function as specified by https://tools.ietf.org/html/rfc5869. |
| |
| use std::prelude::v1::*; |
| use std::iter::repeat; |
| use cryptoutil::copy_memory; |
| |
| use digest::Digest; |
| use hmac::Hmac; |
| use mac::Mac; |
| |
| /// Execute the HKDF-Extract function. Applications MUST NOT use this for |
| /// password hashing. |
| /// |
| /// # Arguments |
| /// * digest - The digest function to use. |
| /// * salt - The optional salt value (a non-secret random value) to use. |
| /// * ikm - The input keying material to use. |
| /// * prk - The output buffer to fill with a digest.output_bytes() length |
| /// pseudo random key. |
| pub fn hkdf_extract<D: Digest>(mut digest: D, salt: &[u8], ikm: &[u8], prk: &mut [u8]) { |
| assert!(prk.len() == digest.output_bytes()); |
| digest.reset(); |
| |
| let mut mac = Hmac::new(digest, salt); |
| mac.input(ikm); |
| mac.raw_result(prk); |
| mac.reset(); |
| } |
| |
| /// Execute the HKDF-Expand function. Applications MUST NOT use this for |
| /// password hashing. |
| /// |
| /// # Arguments |
| /// * digest - The digest function to use. |
| /// * prk - The pseudorandom key of at least digest.output_bytes() octets. |
| /// * info - The optional context and application specific information to use. |
| /// * okm - The output buffer to fill with the derived key value. |
| pub fn hkdf_expand<D: Digest>(mut digest: D, prk: &[u8], info: &[u8], okm: &mut [u8]) { |
| digest.reset(); |
| |
| let mut mac = Hmac::new(digest, prk); |
| let os = mac.output_bytes(); |
| let mut t: Vec<u8> = repeat(0).take(os).collect(); |
| let mut n: u8 = 0; |
| |
| for chunk in okm.chunks_mut(os) { |
| // The block index starts at 1. So, this is supposed to run on the first execution. |
| n = n.checked_add(1).expect("HKDF size limit exceeded."); |
| |
| if n != 1 { |
| mac.input(&t[..]); |
| } |
| let nbuf = [n]; |
| mac.input(info); |
| mac.input(&nbuf); |
| mac.raw_result(&mut t); |
| mac.reset(); |
| let chunk_len = chunk.len(); |
| copy_memory(&t[..chunk_len], chunk); |
| } |
| } |
| |
| #[cfg(test)] |
| mod test { |
| use std::iter::repeat; |
| |
| use digest::Digest; |
| use sha1::Sha1; |
| use sha2::Sha256; |
| use hkdf::{hkdf_extract, hkdf_expand}; |
| |
| struct TestVector<D: Digest>{ |
| digest: D, |
| ikm: Vec<u8>, |
| salt: Vec<u8>, |
| info: Vec<u8>, |
| l: usize, |
| |
| prk: Vec<u8>, |
| okm: Vec<u8>, |
| } |
| |
| #[test] |
| fn test_hkdf_rfc5869_sha256_vectors() { |
| let test_vectors = vec!( |
| TestVector{ |
| digest: Sha256::new(), |
| ikm: repeat(0x0b).take(22).collect(), |
| salt: (0x00..0x0c + 1).collect(), |
| info: (0xf0..0xf9 + 1).collect(), |
| l: 42, |
| prk: vec![ |
| 0x07, 0x77, 0x09, 0x36, 0x2c, 0x2e, 0x32, 0xdf, |
| 0x0d, 0xdc, 0x3f, 0x0d, 0xc4, 0x7b, 0xba, 0x63, |
| 0x90, 0xb6, 0xc7, 0x3b, 0xb5, 0x0f, 0x9c, 0x31, |
| 0x22, 0xec, 0x84, 0x4a, 0xd7, 0xc2, 0xb3, 0xe5 ], |
| okm: vec![ |
| 0x3c, 0xb2, 0x5f, 0x25, 0xfa, 0xac, 0xd5, 0x7a, |
| 0x90, 0x43, 0x4f, 0x64, 0xd0, 0x36, 0x2f, 0x2a, |
| 0x2d, 0x2d, 0x0a, 0x90, 0xcf, 0x1a, 0x5a, 0x4c, |
| 0x5d, 0xb0, 0x2d, 0x56, 0xec, 0xc4, 0xc5, 0xbf, |
| 0x34, 0x00, 0x72, 0x08, 0xd5, 0xb8, 0x87, 0x18, |
| 0x58, 0x65 ], |
| }, |
| TestVector{ |
| digest: Sha256::new(), |
| ikm: (0x00..0x4f + 1).collect(), |
| salt: (0x60..0xaf + 1).collect(), |
| info: (0xb0..0xff + 1).map(|x| x as u8).collect(), |
| l: 82, |
| prk: vec![ |
| 0x06, 0xa6, 0xb8, 0x8c, 0x58, 0x53, 0x36, 0x1a, |
| 0x06, 0x10, 0x4c, 0x9c, 0xeb, 0x35, 0xb4, 0x5c, |
| 0xef, 0x76, 0x00, 0x14, 0x90, 0x46, 0x71, 0x01, |
| 0x4a, 0x19, 0x3f, 0x40, 0xc1, 0x5f, 0xc2, 0x44 ], |
| okm: vec![ |
| 0xb1, 0x1e, 0x39, 0x8d, 0xc8, 0x03, 0x27, 0xa1, |
| 0xc8, 0xe7, 0xf7, 0x8c, 0x59, 0x6a, 0x49, 0x34, |
| 0x4f, 0x01, 0x2e, 0xda, 0x2d, 0x4e, 0xfa, 0xd8, |
| 0xa0, 0x50, 0xcc, 0x4c, 0x19, 0xaf, 0xa9, 0x7c, |
| 0x59, 0x04, 0x5a, 0x99, 0xca, 0xc7, 0x82, 0x72, |
| 0x71, 0xcb, 0x41, 0xc6, 0x5e, 0x59, 0x0e, 0x09, |
| 0xda, 0x32, 0x75, 0x60, 0x0c, 0x2f, 0x09, 0xb8, |
| 0x36, 0x77, 0x93, 0xa9, 0xac, 0xa3, 0xdb, 0x71, |
| 0xcc, 0x30, 0xc5, 0x81, 0x79, 0xec, 0x3e, 0x87, |
| 0xc1, 0x4c, 0x01, 0xd5, 0xc1, 0xf3, 0x43, 0x4f, |
| 0x1d, 0x87 ], |
| }, |
| TestVector{ |
| digest: Sha256::new(), |
| ikm: repeat(0x0b).take(22).collect(), |
| salt: vec![], |
| info: vec![], |
| l:42, |
| prk: vec![ |
| 0x19, 0xef, 0x24, 0xa3, 0x2c, 0x71, 0x7b, 0x16, |
| 0x7f, 0x33, 0xa9, 0x1d, 0x6f, 0x64, 0x8b, 0xdf, |
| 0x96, 0x59, 0x67, 0x76, 0xaf, 0xdb, 0x63, 0x77, |
| 0xac, 0x43, 0x4c, 0x1c, 0x29, 0x3c, 0xcb, 0x04 ], |
| okm: vec![ |
| 0x8d, 0xa4, 0xe7, 0x75, 0xa5, 0x63, 0xc1, 0x8f, |
| 0x71, 0x5f, 0x80, 0x2a, 0x06, 0x3c, 0x5a, 0x31, |
| 0xb8, 0xa1, 0x1f, 0x5c, 0x5e, 0xe1, 0x87, 0x9e, |
| 0xc3, 0x45, 0x4e, 0x5f, 0x3c, 0x73, 0x8d, 0x2d, |
| 0x9d, 0x20, 0x13, 0x95, 0xfa, 0xa4, 0xb6, 0x1a, |
| 0x96, 0xc8 ], |
| }, |
| ); |
| |
| for t in test_vectors.iter() { |
| let mut prk: Vec<u8> = repeat(0).take(t.prk.len()).collect(); |
| hkdf_extract(t.digest, &t.salt[..], &t.ikm[..], &mut prk); |
| assert!(prk == t.prk); |
| |
| let mut okm: Vec<u8> = repeat(0).take(t.okm.len()).collect(); |
| assert!(okm.len() == t.l); |
| hkdf_expand(t.digest, &prk[..], &t.info[..], &mut okm); |
| assert!(okm == t.okm); |
| } |
| } |
| |
| #[test] |
| fn test_hkdf_rfc5869_sha1_vectors() { |
| let test_vectors = vec!( |
| TestVector{ |
| digest: Sha1::new(), |
| ikm: repeat(0x0b).take(11).collect(), |
| salt: (0x00..0x0c + 1).collect(), |
| info: (0xf0..0xf9 + 1).collect(), |
| l: 42, |
| prk: vec![ |
| 0x9b, 0x6c, 0x18, 0xc4, 0x32, 0xa7, 0xbf, 0x8f, |
| 0x0e, 0x71, 0xc8, 0xeb, 0x88, 0xf4, 0xb3, 0x0b, |
| 0xaa, 0x2b, 0xa2, 0x43 ], |
| okm: vec![ |
| 0x08, 0x5a, 0x01, 0xea, 0x1b, 0x10, 0xf3, 0x69, |
| 0x33, 0x06, 0x8b, 0x56, 0xef, 0xa5, 0xad, 0x81, |
| 0xa4, 0xf1, 0x4b, 0x82, 0x2f, 0x5b, 0x09, 0x15, |
| 0x68, 0xa9, 0xcd, 0xd4, 0xf1, 0x55, 0xfd, 0xa2, |
| 0xc2, 0x2e, 0x42, 0x24, 0x78, 0xd3, 0x05, 0xf3, |
| 0xf8, 0x96 ], |
| }, |
| TestVector{ |
| digest: Sha1::new(), |
| ikm: (0x00..0x4f + 1).collect(), |
| salt: (0x60..0xaf + 1).collect(), |
| info: (0xb0..0xff + 1).map(|x| x as u8).collect(), |
| l: 82, |
| prk: vec![ |
| 0x8a, 0xda, 0xe0, 0x9a, 0x2a, 0x30, 0x70, 0x59, |
| 0x47, 0x8d, 0x30, 0x9b, 0x26, 0xc4, 0x11, 0x5a, |
| 0x22, 0x4c, 0xfa, 0xf6 ], |
| okm: vec![ |
| 0x0b, 0xd7, 0x70, 0xa7, 0x4d, 0x11, 0x60, 0xf7, |
| 0xc9, 0xf1, 0x2c, 0xd5, 0x91, 0x2a, 0x06, 0xeb, |
| 0xff, 0x6a, 0xdc, 0xae, 0x89, 0x9d, 0x92, 0x19, |
| 0x1f, 0xe4, 0x30, 0x56, 0x73, 0xba, 0x2f, 0xfe, |
| 0x8f, 0xa3, 0xf1, 0xa4, 0xe5, 0xad, 0x79, 0xf3, |
| 0xf3, 0x34, 0xb3, 0xb2, 0x02, 0xb2, 0x17, 0x3c, |
| 0x48, 0x6e, 0xa3, 0x7c, 0xe3, 0xd3, 0x97, 0xed, |
| 0x03, 0x4c, 0x7f, 0x9d, 0xfe, 0xb1, 0x5c, 0x5e, |
| 0x92, 0x73, 0x36, 0xd0, 0x44, 0x1f, 0x4c, 0x43, |
| 0x00, 0xe2, 0xcf, 0xf0, 0xd0, 0x90, 0x0b, 0x52, |
| 0xd3, 0xb4 ], |
| }, |
| TestVector{ |
| digest: Sha1::new(), |
| ikm: repeat(0x0b).take(22).collect(), |
| salt: vec![], |
| info: vec![], |
| l:42, |
| prk: vec![ |
| 0xda, 0x8c, 0x8a, 0x73, 0xc7, 0xfa, 0x77, 0x28, |
| 0x8e, 0xc6, 0xf5, 0xe7, 0xc2, 0x97, 0x78, 0x6a, |
| 0xa0, 0xd3, 0x2d, 0x01 ], |
| okm: vec![ |
| 0x0a, 0xc1, 0xaf, 0x70, 0x02, 0xb3, 0xd7, 0x61, |
| 0xd1, 0xe5, 0x52, 0x98, 0xda, 0x9d, 0x05, 0x06, |
| 0xb9, 0xae, 0x52, 0x05, 0x72, 0x20, 0xa3, 0x06, |
| 0xe0, 0x7b, 0x6b, 0x87, 0xe8, 0xdf, 0x21, 0xd0, |
| 0xea, 0x00, 0x03, 0x3d, 0xe0, 0x39, 0x84, 0xd3, |
| 0x49, 0x18 ], |
| }, |
| ); |
| |
| for t in test_vectors.iter() { |
| let mut prk: Vec<u8> = repeat(0).take(t.prk.len()).collect(); |
| hkdf_extract(t.digest, &t.salt[..], &t.ikm[..], &mut prk); |
| assert!(prk == t.prk); |
| |
| let mut okm: Vec<u8> = repeat(0).take(t.okm.len()).collect(); |
| assert!(okm.len() == t.l); |
| hkdf_expand(t.digest, &prk[..], &t.info[..], &mut okm); |
| assert!(okm == t.okm); |
| } |
| } |
| } |
