feat(ext/crypto): implement importKey and deriveBits for Pbkdf2

ext/crypto/00_crypto.js

@@ -56,6 +56,7 @@
     RsaPssParams: {},
     EcdsaParams: { hash: "HashAlgorithmIdentifier" },
     HmacImportParams: { hash: "HashAlgorithmIdentifier" },
+    Pbkdf2Params: { hash: "HashAlgorithmIdentifier", salt: "BufferSource" },
     RsaOaepParams: { label: "BufferSource" },
   };
 
@@ -86,6 +87,10 @@
     },
     "importKey": {
       "HMAC": "HmacImportParams",
+      "PBKDF2": null,
+    },
+    "deriveBits": {
+      "PBKDF2": "Pbkdf2Params",
     },
     "encrypt": {
       "RSA-OAEP": "RsaOaepParams",
@@ -657,18 +662,18 @@
 
       const normalizedAlgorithm = normalizeAlgorithm(algorithm, "importKey");
 
-      if (
-        ArrayPrototypeFind(
-          keyUsages,
-          (u) => !ArrayPrototypeIncludes(["sign", "verify"], u),
-        ) !== undefined
-      ) {
-        throw new DOMException("Invalid key usages", "SyntaxError");
-      }
-
       switch (normalizedAlgorithm.name) {
         // https://w3c.github.io/webcrypto/#hmac-operations
         case "HMAC": {
+          if (
+            ArrayPrototypeFind(
+              keyUsages,
+              (u) => !ArrayPrototypeIncludes(["sign", "verify"], u),
+            ) !== undefined
+          ) {
+            throw new DOMException("Invalid key usages", "SyntaxError");
+          }
+
           switch (format) {
             case "raw": {
               const hash = normalizedAlgorithm.hash;
@@ -726,6 +731,52 @@
         // TODO(@littledivy): RSASSA-PKCS1-v1_5
         // TODO(@littledivy): RSA-PSS
         // TODO(@littledivy): ECDSA
+        case "PBKDF2": {
+          // 1.
+          if (format !== "raw") {
+            throw new DOMException("Format not supported", "NotSupportedError");
+          }
+
+          // 2.
+          if (
+            ArrayPrototypeFind(
+              keyUsages,
+              (u) => !ArrayPrototypeIncludes(["deriveKey", "deriveBits"], u),
+            ) !== undefined
+          ) {
+            throw new DOMException("Invalid key usages", "SyntaxError");
+          }
+
+          // 3.
+          if (extractable !== false) {
+            throw new DOMException(
+              "Key must not be extractable",
+              "SyntaxError",
+            );
+          }
+
+          // 4.
+          const handle = {};
+          WeakMapPrototypeSet(KEY_STORE, handle, {
+            type: "raw",
+            data: keyData,
+          });
+
+          // 5-9.
+          const algorithm = {
+            name: "PBKDF2",
+          };
+          const key = constructKey(
+            "secret",
+            false,
+            usageIntersection(keyUsages, recognisedUsages),
+            algorithm,
+            handle,
+          );
+
+          // 10.
+          return key;
+        }
         default:
           throw new DOMException("Not implemented", "NotSupportedError");
       }
@@ -782,6 +833,48 @@
       }
     }
 
+    /**
+    * @param {AlgorithmIdentifier} algorithm
+    * @param {CryptoKey} baseKey
+    * @param {number} length
+    * @returns {Promise<ArrayBuffer>}
+    */
+    async deriveBits(algorithm, baseKey, length) {
+      webidl.assertBranded(this, SubtleCrypto);
+      const prefix = "Failed to execute 'deriveBits' on 'SubtleCrypto'";
+      webidl.requiredArguments(arguments.length, 3, { prefix });
+      algorithm = webidl.converters.AlgorithmIdentifier(algorithm, {
+        prefix,
+        context: "Argument 1",
+      });
+      baseKey = webidl.converters.CryptoKey(baseKey, {
+        prefix,
+        context: "Argument 2",
+      });
+      length = webidl.converters["unsigned long"](length, {
+        prefix,
+        context: "Argument 3",
+      });
+
+      // 2.
+      const normalizedAlgorithm = normalizeAlgorithm(algorithm, "deriveBits");
+      // 4-6.
+      const result = await deriveBits(normalizedAlgorithm, baseKey, length);
+      // 7.
+      if (normalizedAlgorithm.name !== baseKey[_algorithm].name) {
+        throw new DOMException("InvalidAccessError", "Invalid algorithm name");
+      }
+      // 8.
+      if (!ArrayPrototypeIncludes(baseKey[_usages], "deriveBits")) {
+        throw new DOMException(
+          "InvalidAccessError",
+          "baseKey usages does not contain `deriveBits`",
+        );
+      }
+      // 9-10.
+      return result;
+    }
+
     /**
      * @param {string} algorithm
      * @param {CryptoKey} key
@@ -1185,6 +1278,52 @@
     }
   }
 
+  async function deriveBits(normalizedAlgorithm, baseKey, length) {
+    switch (normalizedAlgorithm.name) {
+      case "PBKDF2": {
+        // 1.
+        if (length == null || length == 0 || length % 8 !== 0) {
+          throw new DOMException("Invalid length", "OperationError");
+        }
+
+        if (normalizedAlgorithm.iterations == 0) {
+          throw new DOMException(
+            "iterations must not be zero",
+            "OperationError",
+          );
+        }
+
+        const handle = baseKey[_handle];
+        const keyData = WeakMapPrototypeGet(KEY_STORE, handle);
+
+        if (ArrayBufferIsView(normalizedAlgorithm.salt)) {
+          normalizedAlgorithm.salt = new Uint8Array(
+            normalizedAlgorithm.salt.buffer,
+            normalizedAlgorithm.salt.byteOffset,
+            normalizedAlgorithm.salt.byteLength,
+          );
+        } else {
+          normalizedAlgorithm.salt = new Uint8Array(normalizedAlgorithm.salt);
+        }
+        normalizedAlgorithm.salt = TypedArrayPrototypeSlice(
+          normalizedAlgorithm.salt,
+        );
+
+        const buf = await core.opAsync("op_crypto_derive_bits", {
+          key: keyData,
+          algorithm: "PBKDF2",
+          hash: normalizedAlgorithm.hash.name,
+          iterations: normalizedAlgorithm.iterations,
+          length,
+        }, normalizedAlgorithm.salt);
+
+        return buf.buffer;
+      }
+      default:
+        throw new DOMException("Not implemented", "NotSupportedError");
+    }
+  }
+
   const subtle = webidl.createBranded(SubtleCrypto);
 
   class Crypto {

ext/crypto/01_webidl.js

@@ -178,6 +178,29 @@
   webidl.converters.HmacImportParams = webidl
     .createDictionaryConverter("HmacImportParams", dictHmacImportParams);
 
+  const dictPbkdf2Params = [
+    ...dictAlgorithm,
+    {
+      key: "hash",
+      converter: webidl.converters.HashAlgorithmIdentifier,
+      required: true,
+    },
+    {
+      key: "iterations",
+      converter: (V, opts) =>
+        webidl.converters["unsigned long"](V, { ...opts, enforceRange: true }),
+      required: true,
+    },
+    {
+      key: "salt",
+      converter: webidl.converters["BufferSource"],
+      required: true,
+    },
+  ];
+
+  webidl.converters.Pbkdf2Params = webidl
+    .createDictionaryConverter("Pbkdf2Params", dictPbkdf2Params);
+
   webidl.converters.CryptoKey = webidl.createInterfaceConverter(
     "CryptoKey",
     CryptoKey,

ext/crypto/key.rs

@@ -114,4 +114,6 @@ pub enum Algorithm {
   AesKw,
   #[serde(rename = "HMAC")]
   Hmac,
+  #[serde(rename = "PBKDF2")]
+  Pbkdf2,
 }

ext/crypto/lib.rs

@@ -15,6 +15,7 @@ use serde::Deserialize;
 
 use std::cell::RefCell;
 use std::convert::TryInto;
+use std::num::NonZeroU32;
 use std::rc::Rc;
 
 use lazy_static::lazy_static;
@@ -27,6 +28,7 @@ use rand::SeedableRng;
 use ring::digest;
 use ring::hmac::Algorithm as HmacAlgorithm;
 use ring::hmac::Key as HmacKey;
+use ring::pbkdf2;
 use ring::rand as RingRand;
 use ring::rand::SecureRandom;
 use ring::signature::EcdsaKeyPair;
@@ -74,6 +76,7 @@ pub fn init(maybe_seed: Option<u64>) -> Extension {
       ("op_crypto_generate_key", op_async(op_crypto_generate_key)),
       ("op_crypto_sign_key", op_async(op_crypto_sign_key)),
       ("op_crypto_verify_key", op_async(op_crypto_verify_key)),
+      ("op_crypto_derive_bits", op_async(op_crypto_derive_bits)),
       ("op_crypto_encrypt_key", op_async(op_crypto_encrypt_key)),
       ("op_crypto_decrypt_key", op_async(op_crypto_decrypt_key)),
       ("op_crypto_subtle_digest", op_async(op_crypto_subtle_digest)),
@@ -519,6 +522,45 @@ pub async fn op_crypto_verify_key(
   Ok(verification)
 }
 
+#[derive(Deserialize)]
+#[serde(rename_all = "camelCase")]
+pub struct DeriveKeyArg {
+  key: KeyData,
+  algorithm: Algorithm,
+  hash: Option<CryptoHash>,
+  length: usize,
+  iterations: Option<u32>,
+}
+
+pub async fn op_crypto_derive_bits(
+  _state: Rc<RefCell<OpState>>,
+  args: DeriveKeyArg,
+  zero_copy: Option<ZeroCopyBuf>,
+) -> Result<ZeroCopyBuf, AnyError> {
+  let zero_copy = zero_copy.ok_or_else(null_opbuf)?;
+  let salt = &*zero_copy;
+  let algorithm = args.algorithm;
+  match algorithm {
+    Algorithm::Pbkdf2 => {
+      let algorithm = match args.hash.ok_or_else(not_supported)? {
+        CryptoHash::Sha1 => pbkdf2::PBKDF2_HMAC_SHA1,
+        CryptoHash::Sha256 => pbkdf2::PBKDF2_HMAC_SHA256,
+        CryptoHash::Sha384 => pbkdf2::PBKDF2_HMAC_SHA384,
+        CryptoHash::Sha512 => pbkdf2::PBKDF2_HMAC_SHA512,
+      };
+
+      // This will never panic. We have already checked length earlier.
+      let iterations =
+        NonZeroU32::new(args.iterations.ok_or_else(not_supported)?).unwrap();
+      let secret = args.key.data;
+      let mut out = vec![0; args.length / 8];
+      pbkdf2::derive(algorithm, iterations, salt, &secret, &mut out);
+      Ok(out.into())
+    }
+    _ => Err(type_error("Unsupported algorithm".to_string())),
+  }
+}
+
 #[derive(Deserialize)]
 #[serde(rename_all = "camelCase")]
 pub struct EncryptArg {