LibWeb: Implement AES-CTR.importKey

This commit is contained in:
stelar7 2024-10-30 22:44:20 +01:00 committed by Andreas Kling
parent 21a32e4b6d
commit 0864436383
Notes: github-actions[bot] 2024-10-31 07:16:24 +00:00
3 changed files with 137 additions and 0 deletions

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@ -1396,6 +1396,127 @@ WebIDL::ExceptionOr<JS::Value> AesCbc::get_key_length(AlgorithmParams const& par
return JS::Value(length);
}
WebIDL::ExceptionOr<JS::NonnullGCPtr<CryptoKey>> AesCtr::import_key(AlgorithmParams const&, Bindings::KeyFormat format, CryptoKey::InternalKeyData key_data, bool extractable, Vector<Bindings::KeyUsage> const& key_usages)
{
// 1. If usages contains an entry which is not one of "encrypt", "decrypt", "wrapKey" or "unwrapKey", then throw a SyntaxError.
for (auto& usage : key_usages) {
if (usage != Bindings::KeyUsage::Encrypt && usage != Bindings::KeyUsage::Decrypt && usage != Bindings::KeyUsage::Wrapkey && usage != Bindings::KeyUsage::Unwrapkey) {
return WebIDL::SyntaxError::create(m_realm, MUST(String::formatted("Invalid key usage '{}'", idl_enum_to_string(usage))));
}
}
ByteBuffer data;
// 2. If format is "raw":
if (format == Bindings::KeyFormat::Raw) {
// 1. Let data be the octet string contained in keyData.
data = key_data.get<ByteBuffer>();
// 2. If the length in bits of data is not 128, 192 or 256 then throw a DataError.
auto length_in_bits = data.size() * 8;
if (length_in_bits != 128 && length_in_bits != 192 && length_in_bits != 256) {
return WebIDL::DataError::create(m_realm, MUST(String::formatted("Invalid key length '{}' bits (must be either 128, 192, or 256 bits)", length_in_bits)));
}
}
// 2. If format is "jwk":
else if (format == Bindings::KeyFormat::Jwk) {
// 1. -> If keyData is a JsonWebKey dictionary:
// Let jwk equal keyData.
// -> Otherwise:
// Throw a DataError.
if (!key_data.has<Bindings::JsonWebKey>())
return WebIDL::DataError::create(m_realm, "keyData is not a JsonWebKey dictionary"_string);
auto& jwk = key_data.get<Bindings::JsonWebKey>();
// 2. If the kty field of jwk is not "oct", then throw a DataError.
if (jwk.kty != "oct"_string)
return WebIDL::DataError::create(m_realm, "Invalid key type"_string);
// 3. If jwk does not meet the requirements of Section 6.4 of JSON Web Algorithms [JWA], then throw a DataError.
// Specifically, those requirements are:
// * the member "k" is used to represent a symmetric key (or another key whose value is a single octet sequence).
// * An "alg" member SHOULD also be present to identify the algorithm intended to be used with the key,
// unless the application uses another means or convention to determine the algorithm used.
if (!jwk.k.has_value())
return WebIDL::DataError::create(m_realm, "Missing 'k' field"_string);
if (!jwk.alg.has_value())
return WebIDL::DataError::create(m_realm, "Missing 'alg' field"_string);
// 4. Let data be the octet string obtained by decoding the k field of jwk.
data = TRY(parse_jwk_symmetric_key(m_realm, jwk));
// 5. -> If data has length 128 bits:
// If the alg field of jwk is present, and is not "A128CTR", then throw a DataError.
// -> If data has length 192 bits:
// If the alg field of jwk is present, and is not "A192CTR", then throw a DataError.
// -> If data has length 256 bits:
// If the alg field of jwk is present, and is not "A256CTR", then throw a DataError.
// -> Otherwise:
// throw a DataError.
auto data_bits = data.size() * 8;
auto const& alg = jwk.alg;
if (data_bits == 128 && alg != "A128CTR") {
return WebIDL::DataError::create(m_realm, "Contradictory key size: key has 128 bits, but alg specifies non-128-bit algorithm"_string);
} else if (data_bits == 192 && alg != "A192CTR") {
return WebIDL::DataError::create(m_realm, "Contradictory key size: key has 192 bits, but alg specifies non-192-bit algorithm"_string);
} else if (data_bits == 256 && alg != "A256CTR") {
return WebIDL::DataError::create(m_realm, "Contradictory key size: key has 256 bits, but alg specifies non-256-bit algorithm"_string);
} else {
return WebIDL::DataError::create(m_realm, MUST(String::formatted("Invalid key size: {} bits", data_bits)));
}
// 6. If usages is non-empty and the use field of jwk is present and is not "enc", then throw a DataError.
if (!key_usages.is_empty() && jwk.use.has_value() && *jwk.use != "enc"_string)
return WebIDL::DataError::create(m_realm, "Invalid use field"_string);
// 7. If the key_ops field of jwk is present, and is invalid according to the requirements of JSON Web Key [JWK]
// or does not contain all of the specified usages values, then throw a DataError.
// FIXME: Validate jwk.key_ops against requirements in https://www.rfc-editor.org/rfc/rfc7517#section-4.3
if (jwk.key_ops.has_value()) {
for (auto const& usage : key_usages) {
if (!jwk.key_ops->contains_slow(Bindings::idl_enum_to_string(usage)))
return WebIDL::DataError::create(m_realm, MUST(String::formatted("Missing key_ops field: {}", Bindings::idl_enum_to_string(usage))));
}
}
// 8. If the ext field of jwk is present and has the value false and extractable is true, then throw a DataError.
if (jwk.ext.has_value() && !*jwk.ext && extractable)
return WebIDL::DataError::create(m_realm, "Invalid ext field"_string);
}
// 2. Otherwise:
else {
// 1. throw a NotSupportedError.
return WebIDL::NotSupportedError::create(m_realm, "Only raw and jwk formats are supported"_string);
}
auto data_bits = data.size() * 8;
// 3. Let key be a new CryptoKey object representing an AES key with value data.
auto key = CryptoKey::create(m_realm, move(data));
// 4. Set the [[type]] internal slot of key to "secret".
key->set_type(Bindings::KeyType::Secret);
// 5. Let algorithm be a new AesKeyAlgorithm.
auto algorithm = AesKeyAlgorithm::create(m_realm);
// 6. Set the name attribute of algorithm to "AES-CTR".
algorithm->set_name("AES-CTR"_string);
// 7. Set the length attribute of algorithm to the length, in bits, of data.
algorithm->set_length(data_bits);
// 8. Set the [[algorithm]] internal slot of key to algorithm.
key->set_algorithm(algorithm);
// 9. Return key.
return key;
}
// https://w3c.github.io/webcrypto/#hkdf-operations
WebIDL::ExceptionOr<JS::NonnullGCPtr<CryptoKey>> HKDF::import_key(AlgorithmParams const&, Bindings::KeyFormat format, CryptoKey::InternalKeyData key_data, bool extractable, Vector<Bindings::KeyUsage> const& key_usages)
{

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@ -327,6 +327,19 @@ private:
}
};
class AesCtr : public AlgorithmMethods {
public:
virtual WebIDL::ExceptionOr<JS::NonnullGCPtr<CryptoKey>> import_key(AlgorithmParams const&, Bindings::KeyFormat, CryptoKey::InternalKeyData, bool, Vector<Bindings::KeyUsage> const&) override;
static NonnullOwnPtr<AlgorithmMethods> create(JS::Realm& realm) { return adopt_own(*new AesCtr(realm)); }
private:
explicit AesCtr(JS::Realm& realm)
: AlgorithmMethods(realm)
{
}
};
class HKDF : public AlgorithmMethods {
public:
virtual WebIDL::ExceptionOr<JS::NonnullGCPtr<CryptoKey>> import_key(AlgorithmParams const&, Bindings::KeyFormat, CryptoKey::InternalKeyData, bool, Vector<Bindings::KeyUsage> const&) override;

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@ -776,6 +776,9 @@ SupportedAlgorithmsMap supported_algorithms()
define_an_algorithm<AesCbc>("exportKey"_string, "AES-CBC"_string);
define_an_algorithm<AesCbc, AesDerivedKeyParams>("get key length"_string, "AES-CBC"_string);
// https://w3c.github.io/webcrypto/#aes-ctr-registration
define_an_algorithm<AesCtr>("importKey"_string, "AES-CTR"_string);
// https://w3c.github.io/webcrypto/#hkdf
define_an_algorithm<HKDF>("importKey"_string, "HKDF"_string);
define_an_algorithm<HKDF, HKDFParams>("deriveBits"_string, "HKDF"_string);