script/dom/subtlecrypto/
pbkdf2_operation.rs

1/* This Source Code Form is subject to the terms of the Mozilla Public
2 * License, v. 2.0. If a copy of the MPL was not distributed with this
3 * file, You can obtain one at https://mozilla.org/MPL/2.0/. */
4
5use std::num::NonZero;
6
7use aws_lc_rs::pbkdf2;
8
9use crate::dom::bindings::codegen::Bindings::CryptoKeyBinding::{KeyType, KeyUsage};
10use crate::dom::bindings::codegen::Bindings::SubtleCryptoBinding::KeyFormat;
11use crate::dom::bindings::error::Error;
12use crate::dom::bindings::root::DomRoot;
13use crate::dom::cryptokey::{CryptoKey, Handle};
14use crate::dom::globalscope::GlobalScope;
15use crate::dom::subtlecrypto::{
16    ALG_PBKDF2, ALG_SHA1, ALG_SHA256, ALG_SHA384, ALG_SHA512, KeyAlgorithmAndDerivatives,
17    SubtleKeyAlgorithm, SubtlePbkdf2Params,
18};
19use crate::script_runtime::CanGc;
20
21/// <https://w3c.github.io/webcrypto/#pbkdf2-operations-derive-bits>
22pub(crate) fn derive_bits(
23    normalized_algorithm: &SubtlePbkdf2Params,
24    key: &CryptoKey,
25    length: Option<u32>,
26) -> Result<Vec<u8>, Error> {
27    // Step 1. If length is null or is not a multiple of 8, then throw an OperationError.
28    let Some(length) = length else {
29        return Err(Error::Operation);
30    };
31    if length % 8 != 0 {
32        return Err(Error::Operation);
33    };
34
35    // Step 2. If the iterations member of normalizedAlgorithm is zero, then throw an OperationError.
36    let Ok(iterations) = NonZero::<u32>::try_from(normalized_algorithm.iterations) else {
37        return Err(Error::Operation);
38    };
39
40    // Step 3. If length is zero, return an empty byte sequence.
41    if length == 0 {
42        return Ok(Vec::new());
43    }
44
45    // Step 4. Let prf be the MAC Generation function described in Section 4 of [FIPS-198-1] using
46    // the hash function described by the hash member of normalizedAlgorithm.
47    let prf = match normalized_algorithm.hash.name.as_str() {
48        ALG_SHA1 => pbkdf2::PBKDF2_HMAC_SHA1,
49        ALG_SHA256 => pbkdf2::PBKDF2_HMAC_SHA256,
50        ALG_SHA384 => pbkdf2::PBKDF2_HMAC_SHA384,
51        ALG_SHA512 => pbkdf2::PBKDF2_HMAC_SHA512,
52        _ => {
53            return Err(Error::NotSupported);
54        },
55    };
56
57    // Step 5. Let result be the result of performing the PBKDF2 operation defined in Section 5.2
58    // of [RFC8018] using prf as the pseudo-random function, PRF, the password represented by the
59    // [[handle]] internal slot of key as the password, P, the salt attribute of
60    // normalizedAlgorithm as the salt, S, the value of the iterations attribute of
61    // normalizedAlgorithm as the iteration count, c, and length divided by 8 as the intended key
62    // length, dkLen.
63    let mut result = vec![0; length as usize / 8];
64    pbkdf2::derive(
65        prf,
66        iterations,
67        &normalized_algorithm.salt,
68        key.handle().as_bytes(),
69        &mut result,
70    );
71
72    // Step 5. If the key derivation operation fails, then throw an OperationError.
73    // TODO: Investigate when key derivation can fail and how ring handles that case
74    // (pbkdf2::derive does not return a Result type)
75
76    // Step 6. Return result
77    Ok(result)
78}
79
80/// <https://w3c.github.io/webcrypto/#pbkdf2-operations-import-key>
81pub(crate) fn import_key(
82    global: &GlobalScope,
83    format: KeyFormat,
84    key_data: &[u8],
85    extractable: bool,
86    usages: Vec<KeyUsage>,
87    can_gc: CanGc,
88) -> Result<DomRoot<CryptoKey>, Error> {
89    // Step 1. If format is not "raw", throw a NotSupportedError
90    if format != KeyFormat::Raw {
91        return Err(Error::NotSupported);
92    }
93
94    // Step 2. If usages contains a value that is not "deriveKey" or "deriveBits", then throw a SyntaxError.
95    if usages
96        .iter()
97        .any(|usage| !matches!(usage, KeyUsage::DeriveKey | KeyUsage::DeriveBits)) ||
98        usages.is_empty()
99    {
100        return Err(Error::Syntax(None));
101    }
102
103    // Step 3. If extractable is not false, then throw a SyntaxError.
104    if extractable {
105        return Err(Error::Syntax(None));
106    }
107
108    // Step 4. Let key be a new CryptoKey representing keyData.
109    // Step 5. Set the [[type]] internal slot of key to "secret".
110    // Step 6. Let algorithm be a new KeyAlgorithm object.
111    // Step 7. Set the name attribute of algorithm to "PBKDF2".
112    // Step 8. Set the [[algorithm]] internal slot of key to algorithm.
113    let algorithm = SubtleKeyAlgorithm {
114        name: ALG_PBKDF2.to_string(),
115    };
116    let key = CryptoKey::new(
117        global,
118        KeyType::Secret,
119        extractable,
120        KeyAlgorithmAndDerivatives::KeyAlgorithm(algorithm),
121        usages,
122        Handle::Pbkdf2(key_data.to_vec()),
123        can_gc,
124    );
125
126    // Step 9. Return key.
127    Ok(key)
128}
129
130/// <https://w3c.github.io/webcrypto/#pbkdf2-operations-get-key-length>
131pub(crate) fn get_key_length() -> Result<Option<u32>, Error> {
132    // Step 1. Return null.
133    Ok(None)
134}
script/dom/subtlecrypto/pbkdf2_operation.rs

script/dom/subtlecrypto/
pbkdf2_operation.rs
