feat(views): cache function compilation. Closes #3517.feat/cache-reduce-fun-compilation

Since supporting SpiderMonkey versions > 1.8.5 we compile design
doc functions of the form `function(args) { /* impl */ }` into a
form that is recognise by newer JS engines.

For reduce views, this means a transpilation happens on each
reduce call over the couchjs protocol, which is once for every
level in the b+tree plus one final rereduce across all shards.

down reduce view indexing/querying.

This patch adds caching to the compilation function. This is
implemented by way of producing a SHA-256 hash of all incoming
JS functions and caching them in a global object in the memory
of a `couchjs` process.

The cache is cleared when a `add_fun` message is received, which
happens before new map functions from a new ddoc are loaded into
`couchjs`. This ensures that only functions from a single view &
security context are ever loaded into the cache.

SHA-256 was chosen because it is producing collisions that are
also valid JS functions is unlikley.

This specific SHA-256 implementation was chosen because:
- it is favourably licensed (MIT)
- taken from the Deno (https://deno.land) project, (h/t Martin
  Sonnenholzer for the tip)so we can be reasonably assured this
  has been tested thoroughly.

7 files changed, 1130 insertions, 3 deletions

diff --git a/LICENSE b/LICENSE
index 048ee41a5..9ab87430e 100644
--- a/LICENSE
+++ b/LICENSE
@@ -2267,3 +2267,25 @@ ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
+For sha256.ts/.js
+
+Copyright (c) 2018-2021 the Deno authors.
+Copyright (c) 2014-2017 Chen, Yi-Cyuan
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in
+all copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+THE SOFTWARE.
diff --git a/NOTICE b/NOTICE
index 8fd1befd2..8c8554c01 100644
--- a/NOTICE
+++ b/NOTICE
@@ -197,3 +197,8 @@ This product also includes the following third-party components:
 * weatherreport_getopt.erl
 
   Copyright (C) 2009 Juan Jose Comellas
+
+* sha256.ts
+
+  Copyright (c) 2018-2021 the Deno authors. All rights reserved.
+  Copyright (c) 2014-2017 Chen, Yi-Cyuan
diff --git a/share/server/60/rewrite_fun.js b/share/server/60/rewrite_fun.js
index 1b27a9d14..8ebae3f6c 100644
--- a/share/server/60/rewrite_fun.js
+++ b/share/server/60/rewrite_fun.js
@@ -14,8 +14,13 @@
 // found here:
 //
 //  https://github.com/dmunch/couch-chakra/blob/master/js/normalizeFunction.js
-
 function rewriteFunInt(fun) {
+    const hash = new Sha256();
+    hash.update(fun);
+    const key = hash.toString();
+    if (State.cache[key]) {
+        return State.cache[key];
+    }
     const ast = esprima.parse(fun);
     let idx = ast.body.length - 1;
     let decl = {};
@@ -38,7 +43,9 @@ function rewriteFunInt(fun) {
     }
 
     // Generate source from the rewritten AST
-    return escodegen.generate(ast);
+    const newSource = escodegen.generate(ast);
+    State.cache[key] = newSource;
+    return State.cache[key];
 }
 
 
diff --git a/share/server/sha256.js b/share/server/sha256.js
new file mode 100644
index 000000000..6c6a98fed
--- /dev/null
+++ b/share/server/sha256.js
@@ -0,0 +1,546 @@
+// Licensed under the Apache License, Version 2.0 (the "License"); you may not
+// use this file except in compliance with the License. You may obtain a copy of
+// the License at
+//
+//   http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+// WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+// License for the specific language governing permissions and limitations under
+// the License.
+
+// Copyright 2018-2021 the Deno authors. All rights reserved. MIT license.
+/*
+ * Adapted to deno from:
+ *
+ * [js-sha256]{@link https://github.com/emn178/js-sha256}
+ *
+ * @version 0.9.0
+ * @author Chen, Yi-Cyuan [emn178@gmail.com]
+ * @copyright Chen, Yi-Cyuan 2014-2017
+ * @license MIT
+ */
+ // generated from sha256.ts with these commands:
+ // $ npm install -g typescript
+ // $ tsc --target ES6 sha256.ts
+ // manually remove the two uses of `export class` and just have it be `class`
+var __classPrivateFieldSet = (this && this.__classPrivateFieldSet) || function (receiver, state, value, kind, f) {
+    if (kind === "m") throw new TypeError("Private method is not writable");
+    if (kind === "a" && !f) throw new TypeError("Private accessor was defined without a setter");
+    if (typeof state === "function" ? receiver !== state || !f : !state.has(receiver)) throw new TypeError("Cannot write private member to an object whose class did not declare it");
+    return (kind === "a" ? f.call(receiver, value) : f ? f.value = value : state.set(receiver, value)), value;
+};
+var __classPrivateFieldGet = (this && this.__classPrivateFieldGet) || function (receiver, state, kind, f) {
+    if (kind === "a" && !f) throw new TypeError("Private accessor was defined without a getter");
+    if (typeof state === "function" ? receiver !== state || !f : !state.has(receiver)) throw new TypeError("Cannot read private member from an object whose class did not declare it");
+    return kind === "m" ? f : kind === "a" ? f.call(receiver) : f ? f.value : state.get(receiver);
+};
+var _Sha256_block, _Sha256_blocks, _Sha256_bytes, _Sha256_finalized, _Sha256_first, _Sha256_h0, _Sha256_h1, _Sha256_h2, _Sha256_h3, _Sha256_h4, _Sha256_h5, _Sha256_h6, _Sha256_h7, _Sha256_hashed, _Sha256_hBytes, _Sha256_is224, _Sha256_lastByteIndex, _Sha256_start, _HmacSha256_inner, _HmacSha256_is224, _HmacSha256_oKeyPad, _HmacSha256_sharedMemory;
+const HEX_CHARS = "0123456789abcdef".split("");
+const EXTRA = [-2147483648, 8388608, 32768, 128];
+const SHIFT = [24, 16, 8, 0];
+// deno-fmt-ignore
+const K = [
+    0x428a2f98, 0x71374491, 0xb5c0fbcf, 0xe9b5dba5, 0x3956c25b, 0x59f111f1,
+    0x923f82a4, 0xab1c5ed5, 0xd807aa98, 0x12835b01, 0x243185be, 0x550c7dc3,
+    0x72be5d74, 0x80deb1fe, 0x9bdc06a7, 0xc19bf174, 0xe49b69c1, 0xefbe4786,
+    0x0fc19dc6, 0x240ca1cc, 0x2de92c6f, 0x4a7484aa, 0x5cb0a9dc, 0x76f988da,
+    0x983e5152, 0xa831c66d, 0xb00327c8, 0xbf597fc7, 0xc6e00bf3, 0xd5a79147,
+    0x06ca6351, 0x14292967, 0x27b70a85, 0x2e1b2138, 0x4d2c6dfc, 0x53380d13,
+    0x650a7354, 0x766a0abb, 0x81c2c92e, 0x92722c85, 0xa2bfe8a1, 0xa81a664b,
+    0xc24b8b70, 0xc76c51a3, 0xd192e819, 0xd6990624, 0xf40e3585, 0x106aa070,
+    0x19a4c116, 0x1e376c08, 0x2748774c, 0x34b0bcb5, 0x391c0cb3, 0x4ed8aa4a,
+    0x5b9cca4f, 0x682e6ff3, 0x748f82ee, 0x78a5636f, 0x84c87814, 0x8cc70208,
+    0x90befffa, 0xa4506ceb, 0xbef9a3f7, 0xc67178f2,
+];
+const blocks = [];
+class Sha256 {
+    constructor(is224 = false, sharedMemory = false) {
+        _Sha256_block.set(this, void 0);
+        _Sha256_blocks.set(this, void 0);
+        _Sha256_bytes.set(this, void 0);
+        _Sha256_finalized.set(this, void 0);
+        _Sha256_first.set(this, void 0);
+        _Sha256_h0.set(this, void 0);
+        _Sha256_h1.set(this, void 0);
+        _Sha256_h2.set(this, void 0);
+        _Sha256_h3.set(this, void 0);
+        _Sha256_h4.set(this, void 0);
+        _Sha256_h5.set(this, void 0);
+        _Sha256_h6.set(this, void 0);
+        _Sha256_h7.set(this, void 0);
+        _Sha256_hashed.set(this, void 0);
+        _Sha256_hBytes.set(this, void 0);
+        _Sha256_is224.set(this, void 0);
+        _Sha256_lastByteIndex.set(this, 0);
+        _Sha256_start.set(this, void 0);
+        this.init(is224, sharedMemory);
+    }
+    init(is224, sharedMemory) {
+        if (sharedMemory) {
+            // deno-fmt-ignore
+            blocks[0] = blocks[16] = blocks[1] = blocks[2] = blocks[3] = blocks[4] = blocks[5] = blocks[6] = blocks[7] = blocks[8] = blocks[9] = blocks[10] = blocks[11] = blocks[12] = blocks[13] = blocks[14] = blocks[15] = 0;
+            __classPrivateFieldSet(this, _Sha256_blocks, blocks, "f");
+        }
+        else {
+            __classPrivateFieldSet(this, _Sha256_blocks, [0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0], "f");
+        }
+        if (is224) {
+            __classPrivateFieldSet(this, _Sha256_h0, 0xc1059ed8, "f");
+            __classPrivateFieldSet(this, _Sha256_h1, 0x367cd507, "f");
+            __classPrivateFieldSet(this, _Sha256_h2, 0x3070dd17, "f");
+            __classPrivateFieldSet(this, _Sha256_h3, 0xf70e5939, "f");
+            __classPrivateFieldSet(this, _Sha256_h4, 0xffc00b31, "f");
+            __classPrivateFieldSet(this, _Sha256_h5, 0x68581511, "f");
+            __classPrivateFieldSet(this, _Sha256_h6, 0x64f98fa7, "f");
+            __classPrivateFieldSet(this, _Sha256_h7, 0xbefa4fa4, "f");
+        }
+        else {
+            // 256
+            __classPrivateFieldSet(this, _Sha256_h0, 0x6a09e667, "f");
+            __classPrivateFieldSet(this, _Sha256_h1, 0xbb67ae85, "f");
+            __classPrivateFieldSet(this, _Sha256_h2, 0x3c6ef372, "f");
+            __classPrivateFieldSet(this, _Sha256_h3, 0xa54ff53a, "f");
+            __classPrivateFieldSet(this, _Sha256_h4, 0x510e527f, "f");
+            __classPrivateFieldSet(this, _Sha256_h5, 0x9b05688c, "f");
+            __classPrivateFieldSet(this, _Sha256_h6, 0x1f83d9ab, "f");
+            __classPrivateFieldSet(this, _Sha256_h7, 0x5be0cd19, "f");
+        }
+        __classPrivateFieldSet(this, _Sha256_block, __classPrivateFieldSet(this, _Sha256_start, __classPrivateFieldSet(this, _Sha256_bytes, __classPrivateFieldSet(this, _Sha256_hBytes, 0, "f"), "f"), "f"), "f");
+        __classPrivateFieldSet(this, _Sha256_finalized, __classPrivateFieldSet(this, _Sha256_hashed, false, "f"), "f");
+        __classPrivateFieldSet(this, _Sha256_first, true, "f");
+        __classPrivateFieldSet(this, _Sha256_is224, is224, "f");
+    }
+    /** Update hash
+     *
+     * @param message The message you want to hash.
+     */
+    update(message) {
+        if (__classPrivateFieldGet(this, _Sha256_finalized, "f")) {
+            return this;
+        }
+        let msg;
+        if (message instanceof ArrayBuffer) {
+            msg = new Uint8Array(message);
+        }
+        else {
+            msg = message;
+        }
+        let index = 0;
+        const length = msg.length;
+        const blocks = __classPrivateFieldGet(this, _Sha256_blocks, "f");
+        while (index < length) {
+            let i;
+            if (__classPrivateFieldGet(this, _Sha256_hashed, "f")) {
+                __classPrivateFieldSet(this, _Sha256_hashed, false, "f");
+                blocks[0] = __classPrivateFieldGet(this, _Sha256_block, "f");
+                // deno-fmt-ignore
+                blocks[16] = blocks[1] = blocks[2] = blocks[3] = blocks[4] = blocks[5] = blocks[6] = blocks[7] = blocks[8] = blocks[9] = blocks[10] = blocks[11] = blocks[12] = blocks[13] = blocks[14] = blocks[15] = 0;
+            }
+            if (typeof msg !== "string") {
+                for (i = __classPrivateFieldGet(this, _Sha256_start, "f"); index < length && i < 64; ++index) {
+                    blocks[i >> 2] |= msg[index] << SHIFT[i++ & 3];
+                }
+            }
+            else {
+                for (i = __classPrivateFieldGet(this, _Sha256_start, "f"); index < length && i < 64; ++index) {
+                    let code = msg.charCodeAt(index);
+                    if (code < 0x80) {
+                        blocks[i >> 2] |= code << SHIFT[i++ & 3];
+                    }
+                    else if (code < 0x800) {
+                        blocks[i >> 2] |= (0xc0 | (code >> 6)) << SHIFT[i++ & 3];
+                        blocks[i >> 2] |= (0x80 | (code & 0x3f)) << SHIFT[i++ & 3];
+                    }
+                    else if (code < 0xd800 || code >= 0xe000) {
+                        blocks[i >> 2] |= (0xe0 | (code >> 12)) << SHIFT[i++ & 3];
+                        blocks[i >> 2] |= (0x80 | ((code >> 6) & 0x3f)) << SHIFT[i++ & 3];
+                        blocks[i >> 2] |= (0x80 | (code & 0x3f)) << SHIFT[i++ & 3];
+                    }
+                    else {
+                        code = 0x10000 +
+                            (((code & 0x3ff) << 10) | (msg.charCodeAt(++index) & 0x3ff));
+                        blocks[i >> 2] |= (0xf0 | (code >> 18)) << SHIFT[i++ & 3];
+                        blocks[i >> 2] |= (0x80 | ((code >> 12) & 0x3f)) << SHIFT[i++ & 3];
+                        blocks[i >> 2] |= (0x80 | ((code >> 6) & 0x3f)) << SHIFT[i++ & 3];
+                        blocks[i >> 2] |= (0x80 | (code & 0x3f)) << SHIFT[i++ & 3];
+                    }
+                }
+            }
+            __classPrivateFieldSet(this, _Sha256_lastByteIndex, i, "f");
+            __classPrivateFieldSet(this, _Sha256_bytes, __classPrivateFieldGet(this, _Sha256_bytes, "f") + (i - __classPrivateFieldGet(this, _Sha256_start, "f")), "f");
+            if (i >= 64) {
+                __classPrivateFieldSet(this, _Sha256_block, blocks[16], "f");
+                __classPrivateFieldSet(this, _Sha256_start, i - 64, "f");
+                this.hash();
+                __classPrivateFieldSet(this, _Sha256_hashed, true, "f");
+            }
+            else {
+                __classPrivateFieldSet(this, _Sha256_start, i, "f");
+            }
+        }
+        if (__classPrivateFieldGet(this, _Sha256_bytes, "f") > 4294967295) {
+            __classPrivateFieldSet(this, _Sha256_hBytes, __classPrivateFieldGet(this, _Sha256_hBytes, "f") + ((__classPrivateFieldGet(this, _Sha256_bytes, "f") / 4294967296) << 0), "f");
+            __classPrivateFieldSet(this, _Sha256_bytes, __classPrivateFieldGet(this, _Sha256_bytes, "f") % 4294967296, "f");
+        }
+        return this;
+    }
+    finalize() {
+        if (__classPrivateFieldGet(this, _Sha256_finalized, "f")) {
+            return;
+        }
+        __classPrivateFieldSet(this, _Sha256_finalized, true, "f");
+        const blocks = __classPrivateFieldGet(this, _Sha256_blocks, "f");
+        const i = __classPrivateFieldGet(this, _Sha256_lastByteIndex, "f");
+        blocks[16] = __classPrivateFieldGet(this, _Sha256_block, "f");
+        blocks[i >> 2] |= EXTRA[i & 3];
+        __classPrivateFieldSet(this, _Sha256_block, blocks[16], "f");
+        if (i >= 56) {
+            if (!__classPrivateFieldGet(this, _Sha256_hashed, "f")) {
+                this.hash();
+            }
+            blocks[0] = __classPrivateFieldGet(this, _Sha256_block, "f");
+            // deno-fmt-ignore
+            blocks[16] = blocks[1] = blocks[2] = blocks[3] = blocks[4] = blocks[5] = blocks[6] = blocks[7] = blocks[8] = blocks[9] = blocks[10] = blocks[11] = blocks[12] = blocks[13] = blocks[14] = blocks[15] = 0;
+        }
+        blocks[14] = (__classPrivateFieldGet(this, _Sha256_hBytes, "f") << 3) | (__classPrivateFieldGet(this, _Sha256_bytes, "f") >>> 29);
+        blocks[15] = __classPrivateFieldGet(this, _Sha256_bytes, "f") << 3;
+        this.hash();
+    }
+    hash() {
+        let a = __classPrivateFieldGet(this, _Sha256_h0, "f");
+        let b = __classPrivateFieldGet(this, _Sha256_h1, "f");
+        let c = __classPrivateFieldGet(this, _Sha256_h2, "f");
+        let d = __classPrivateFieldGet(this, _Sha256_h3, "f");
+        let e = __classPrivateFieldGet(this, _Sha256_h4, "f");
+        let f = __classPrivateFieldGet(this, _Sha256_h5, "f");
+        let g = __classPrivateFieldGet(this, _Sha256_h6, "f");
+        let h = __classPrivateFieldGet(this, _Sha256_h7, "f");
+        const blocks = __classPrivateFieldGet(this, _Sha256_blocks, "f");
+        let s0;
+        let s1;
+        let maj;
+        let t1;
+        let t2;
+        let ch;
+        let ab;
+        let da;
+        let cd;
+        let bc;
+        for (let j = 16; j < 64; ++j) {
+            // rightrotate
+            t1 = blocks[j - 15];
+            s0 = ((t1 >>> 7) | (t1 << 25)) ^ ((t1 >>> 18) | (t1 << 14)) ^ (t1 >>> 3);
+            t1 = blocks[j - 2];
+            s1 = ((t1 >>> 17) | (t1 << 15)) ^ ((t1 >>> 19) | (t1 << 13)) ^
+                (t1 >>> 10);
+            blocks[j] = (blocks[j - 16] + s0 + blocks[j - 7] + s1) << 0;
+        }
+        bc = b & c;
+        for (let j = 0; j < 64; j += 4) {
+            if (__classPrivateFieldGet(this, _Sha256_first, "f")) {
+                if (__classPrivateFieldGet(this, _Sha256_is224, "f")) {
+                    ab = 300032;
+                    t1 = blocks[0] - 1413257819;
+                    h = (t1 - 150054599) << 0;
+                    d = (t1 + 24177077) << 0;
+                }
+                else {
+                    ab = 704751109;
+                    t1 = blocks[0] - 210244248;
+                    h = (t1 - 1521486534) << 0;
+                    d = (t1 + 143694565) << 0;
+                }
+                __classPrivateFieldSet(this, _Sha256_first, false, "f");
+            }
+            else {
+                s0 = ((a >>> 2) | (a << 30)) ^
+                    ((a >>> 13) | (a << 19)) ^
+                    ((a >>> 22) | (a << 10));
+                s1 = ((e >>> 6) | (e << 26)) ^
+                    ((e >>> 11) | (e << 21)) ^
+                    ((e >>> 25) | (e << 7));
+                ab = a & b;
+                maj = ab ^ (a & c) ^ bc;
+                ch = (e & f) ^ (~e & g);
+                t1 = h + s1 + ch + K[j] + blocks[j];
+                t2 = s0 + maj;
+                h = (d + t1) << 0;
+                d = (t1 + t2) << 0;
+            }
+            s0 = ((d >>> 2) | (d << 30)) ^
+                ((d >>> 13) | (d << 19)) ^
+                ((d >>> 22) | (d << 10));
+            s1 = ((h >>> 6) | (h << 26)) ^
+                ((h >>> 11) | (h << 21)) ^
+                ((h >>> 25) | (h << 7));
+            da = d & a;
+            maj = da ^ (d & b) ^ ab;
+            ch = (h & e) ^ (~h & f);
+            t1 = g + s1 + ch + K[j + 1] + blocks[j + 1];
+            t2 = s0 + maj;
+            g = (c + t1) << 0;
+            c = (t1 + t2) << 0;
+            s0 = ((c >>> 2) | (c << 30)) ^
+                ((c >>> 13) | (c << 19)) ^
+                ((c >>> 22) | (c << 10));
+            s1 = ((g >>> 6) | (g << 26)) ^
+                ((g >>> 11) | (g << 21)) ^
+                ((g >>> 25) | (g << 7));
+            cd = c & d;
+            maj = cd ^ (c & a) ^ da;
+            ch = (g & h) ^ (~g & e);
+            t1 = f + s1 + ch + K[j + 2] + blocks[j + 2];
+            t2 = s0 + maj;
+            f = (b + t1) << 0;
+            b = (t1 + t2) << 0;
+            s0 = ((b >>> 2) | (b << 30)) ^
+                ((b >>> 13) | (b << 19)) ^
+                ((b >>> 22) | (b << 10));
+            s1 = ((f >>> 6) | (f << 26)) ^
+                ((f >>> 11) | (f << 21)) ^
+                ((f >>> 25) | (f << 7));
+            bc = b & c;
+            maj = bc ^ (b & d) ^ cd;
+            ch = (f & g) ^ (~f & h);
+            t1 = e + s1 + ch + K[j + 3] + blocks[j + 3];
+            t2 = s0 + maj;
+            e = (a + t1) << 0;
+            a = (t1 + t2) << 0;
+        }
+        __classPrivateFieldSet(this, _Sha256_h0, (__classPrivateFieldGet(this, _Sha256_h0, "f") + a) << 0, "f");
+        __classPrivateFieldSet(this, _Sha256_h1, (__classPrivateFieldGet(this, _Sha256_h1, "f") + b) << 0, "f");
+        __classPrivateFieldSet(this, _Sha256_h2, (__classPrivateFieldGet(this, _Sha256_h2, "f") + c) << 0, "f");
+        __classPrivateFieldSet(this, _Sha256_h3, (__classPrivateFieldGet(this, _Sha256_h3, "f") + d) << 0, "f");
+        __classPrivateFieldSet(this, _Sha256_h4, (__classPrivateFieldGet(this, _Sha256_h4, "f") + e) << 0, "f");
+        __classPrivateFieldSet(this, _Sha256_h5, (__classPrivateFieldGet(this, _Sha256_h5, "f") + f) << 0, "f");
+        __classPrivateFieldSet(this, _Sha256_h6, (__classPrivateFieldGet(this, _Sha256_h6, "f") + g) << 0, "f");
+        __classPrivateFieldSet(this, _Sha256_h7, (__classPrivateFieldGet(this, _Sha256_h7, "f") + h) << 0, "f");
+    }
+    /** Return hash in hex string. */
+    hex() {
+        this.finalize();
+        const h0 = __classPrivateFieldGet(this, _Sha256_h0, "f");
+        const h1 = __classPrivateFieldGet(this, _Sha256_h1, "f");
+        const h2 = __classPrivateFieldGet(this, _Sha256_h2, "f");
+        const h3 = __classPrivateFieldGet(this, _Sha256_h3, "f");
+        const h4 = __classPrivateFieldGet(this, _Sha256_h4, "f");
+        const h5 = __classPrivateFieldGet(this, _Sha256_h5, "f");
+        const h6 = __classPrivateFieldGet(this, _Sha256_h6, "f");
+        const h7 = __classPrivateFieldGet(this, _Sha256_h7, "f");
+        let hex = HEX_CHARS[(h0 >> 28) & 0x0f] +
+            HEX_CHARS[(h0 >> 24) & 0x0f] +
+            HEX_CHARS[(h0 >> 20) & 0x0f] +
+            HEX_CHARS[(h0 >> 16) & 0x0f] +
+            HEX_CHARS[(h0 >> 12) & 0x0f] +
+            HEX_CHARS[(h0 >> 8) & 0x0f] +
+            HEX_CHARS[(h0 >> 4) & 0x0f] +
+            HEX_CHARS[h0 & 0x0f] +
+            HEX_CHARS[(h1 >> 28) & 0x0f] +
+            HEX_CHARS[(h1 >> 24) & 0x0f] +
+            HEX_CHARS[(h1 >> 20) & 0x0f] +
+            HEX_CHARS[(h1 >> 16) & 0x0f] +
+            HEX_CHARS[(h1 >> 12) & 0x0f] +
+            HEX_CHARS[(h1 >> 8) & 0x0f] +
+            HEX_CHARS[(h1 >> 4) & 0x0f] +
+            HEX_CHARS[h1 & 0x0f] +
+            HEX_CHARS[(h2 >> 28) & 0x0f] +
+            HEX_CHARS[(h2 >> 24) & 0x0f] +
+            HEX_CHARS[(h2 >> 20) & 0x0f] +
+            HEX_CHARS[(h2 >> 16) & 0x0f] +
+            HEX_CHARS[(h2 >> 12) & 0x0f] +
+            HEX_CHARS[(h2 >> 8) & 0x0f] +
+            HEX_CHARS[(h2 >> 4) & 0x0f] +
+            HEX_CHARS[h2 & 0x0f] +
+            HEX_CHARS[(h3 >> 28) & 0x0f] +
+            HEX_CHARS[(h3 >> 24) & 0x0f] +
+            HEX_CHARS[(h3 >> 20) & 0x0f] +
+            HEX_CHARS[(h3 >> 16) & 0x0f] +
+            HEX_CHARS[(h3 >> 12) & 0x0f] +
+            HEX_CHARS[(h3 >> 8) & 0x0f] +
+            HEX_CHARS[(h3 >> 4) & 0x0f] +
+            HEX_CHARS[h3 & 0x0f] +
+            HEX_CHARS[(h4 >> 28) & 0x0f] +
+            HEX_CHARS[(h4 >> 24) & 0x0f] +
+            HEX_CHARS[(h4 >> 20) & 0x0f] +
+            HEX_CHARS[(h4 >> 16) & 0x0f] +
+            HEX_CHARS[(h4 >> 12) & 0x0f] +
+            HEX_CHARS[(h4 >> 8) & 0x0f] +
+            HEX_CHARS[(h4 >> 4) & 0x0f] +
+            HEX_CHARS[h4 & 0x0f] +
+            HEX_CHARS[(h5 >> 28) & 0x0f] +
+            HEX_CHARS[(h5 >> 24) & 0x0f] +
+            HEX_CHARS[(h5 >> 20) & 0x0f] +
+            HEX_CHARS[(h5 >> 16) & 0x0f] +
+            HEX_CHARS[(h5 >> 12) & 0x0f] +
+            HEX_CHARS[(h5 >> 8) & 0x0f] +
+            HEX_CHARS[(h5 >> 4) & 0x0f] +
+            HEX_CHARS[h5 & 0x0f] +
+            HEX_CHARS[(h6 >> 28) & 0x0f] +
+            HEX_CHARS[(h6 >> 24) & 0x0f] +
+            HEX_CHARS[(h6 >> 20) & 0x0f] +
+            HEX_CHARS[(h6 >> 16) & 0x0f] +
+            HEX_CHARS[(h6 >> 12) & 0x0f] +
+            HEX_CHARS[(h6 >> 8) & 0x0f] +
+            HEX_CHARS[(h6 >> 4) & 0x0f] +
+            HEX_CHARS[h6 & 0x0f];
+        if (!__classPrivateFieldGet(this, _Sha256_is224, "f")) {
+            hex += HEX_CHARS[(h7 >> 28) & 0x0f] +
+                HEX_CHARS[(h7 >> 24) & 0x0f] +
+                HEX_CHARS[(h7 >> 20) & 0x0f] +
+                HEX_CHARS[(h7 >> 16) & 0x0f] +
+                HEX_CHARS[(h7 >> 12) & 0x0f] +
+                HEX_CHARS[(h7 >> 8) & 0x0f] +
+                HEX_CHARS[(h7 >> 4) & 0x0f] +
+                HEX_CHARS[h7 & 0x0f];
+        }
+        return hex;
+    }
+    /** Return hash in hex string. */
+    toString() {
+        return this.hex();
+    }
+    /** Return hash in integer array. */
+    digest() {
+        this.finalize();
+        const h0 = __classPrivateFieldGet(this, _Sha256_h0, "f");
+        const h1 = __classPrivateFieldGet(this, _Sha256_h1, "f");
+        const h2 = __classPrivateFieldGet(this, _Sha256_h2, "f");
+        const h3 = __classPrivateFieldGet(this, _Sha256_h3, "f");
+        const h4 = __classPrivateFieldGet(this, _Sha256_h4, "f");
+        const h5 = __classPrivateFieldGet(this, _Sha256_h5, "f");
+        const h6 = __classPrivateFieldGet(this, _Sha256_h6, "f");
+        const h7 = __classPrivateFieldGet(this, _Sha256_h7, "f");
+        const arr = [
+            (h0 >> 24) & 0xff,
+            (h0 >> 16) & 0xff,
+            (h0 >> 8) & 0xff,
+            h0 & 0xff,
+            (h1 >> 24) & 0xff,
+            (h1 >> 16) & 0xff,
+            (h1 >> 8) & 0xff,
+            h1 & 0xff,
+            (h2 >> 24) & 0xff,
+            (h2 >> 16) & 0xff,
+            (h2 >> 8) & 0xff,
+            h2 & 0xff,
+            (h3 >> 24) & 0xff,
+            (h3 >> 16) & 0xff,
+            (h3 >> 8) & 0xff,
+            h3 & 0xff,
+            (h4 >> 24) & 0xff,
+            (h4 >> 16) & 0xff,
+            (h4 >> 8) & 0xff,
+            h4 & 0xff,
+            (h5 >> 24) & 0xff,
+            (h5 >> 16) & 0xff,
+            (h5 >> 8) & 0xff,
+            h5 & 0xff,
+            (h6 >> 24) & 0xff,
+            (h6 >> 16) & 0xff,
+            (h6 >> 8) & 0xff,
+            h6 & 0xff,
+        ];
+        if (!__classPrivateFieldGet(this, _Sha256_is224, "f")) {
+            arr.push((h7 >> 24) & 0xff, (h7 >> 16) & 0xff, (h7 >> 8) & 0xff, h7 & 0xff);
+        }
+        return arr;
+    }
+    /** Return hash in integer array. */
+    array() {
+        return this.digest();
+    }
+    /** Return hash in ArrayBuffer. */
+    arrayBuffer() {
+        this.finalize();
+        const buffer = new ArrayBuffer(__classPrivateFieldGet(this, _Sha256_is224, "f") ? 28 : 32);
+        const dataView = new DataView(buffer);
+        dataView.setUint32(0, __classPrivateFieldGet(this, _Sha256_h0, "f"));
+        dataView.setUint32(4, __classPrivateFieldGet(this, _Sha256_h1, "f"));
+        dataView.setUint32(8, __classPrivateFieldGet(this, _Sha256_h2, "f"));
+        dataView.setUint32(12, __classPrivateFieldGet(this, _Sha256_h3, "f"));
+        dataView.setUint32(16, __classPrivateFieldGet(this, _Sha256_h4, "f"));
+        dataView.setUint32(20, __classPrivateFieldGet(this, _Sha256_h5, "f"));
+        dataView.setUint32(24, __classPrivateFieldGet(this, _Sha256_h6, "f"));
+        if (!__classPrivateFieldGet(this, _Sha256_is224, "f")) {
+            dataView.setUint32(28, __classPrivateFieldGet(this, _Sha256_h7, "f"));
+        }
+        return buffer;
+    }
+}
+_Sha256_block = new WeakMap(), _Sha256_blocks = new WeakMap(), _Sha256_bytes = new WeakMap(), _Sha256_finalized = new WeakMap(), _Sha256_first = new WeakMap(), _Sha256_h0 = new WeakMap(), _Sha256_h1 = new WeakMap(), _Sha256_h2 = new WeakMap(), _Sha256_h3 = new WeakMap(), _Sha256_h4 = new WeakMap(), _Sha256_h5 = new WeakMap(), _Sha256_h6 = new WeakMap(), _Sha256_h7 = new WeakMap(), _Sha256_hashed = new WeakMap(), _Sha256_hBytes = new WeakMap(), _Sha256_is224 = new WeakMap(), _Sha256_lastByteIndex = new WeakMap(), _Sha256_start = new WeakMap();
+class HmacSha256 extends Sha256 {
+    constructor(secretKey, is224 = false, sharedMemory = false) {
+        super(is224, sharedMemory);
+        _HmacSha256_inner.set(this, void 0);
+        _HmacSha256_is224.set(this, void 0);
+        _HmacSha256_oKeyPad.set(this, void 0);
+        _HmacSha256_sharedMemory.set(this, void 0);
+        let key;
+        if (typeof secretKey === "string") {
+            const bytes = [];
+            const length = secretKey.length;
+            let index = 0;
+            for (let i = 0; i < length; ++i) {
+                let code = secretKey.charCodeAt(i);
+                if (code < 0x80) {
+                    bytes[index++] = code;
+                }
+                else if (code < 0x800) {
+                    bytes[index++] = 0xc0 | (code >> 6);
+                    bytes[index++] = 0x80 | (code & 0x3f);
+                }
+                else if (code < 0xd800 || code >= 0xe000) {
+                    bytes[index++] = 0xe0 | (code >> 12);
+                    bytes[index++] = 0x80 | ((code >> 6) & 0x3f);
+                    bytes[index++] = 0x80 | (code & 0x3f);
+                }
+                else {
+                    code = 0x10000 +
+                        (((code & 0x3ff) << 10) | (secretKey.charCodeAt(++i) & 0x3ff));
+                    bytes[index++] = 0xf0 | (code >> 18);
+                    bytes[index++] = 0x80 | ((code >> 12) & 0x3f);
+                    bytes[index++] = 0x80 | ((code >> 6) & 0x3f);
+                    bytes[index++] = 0x80 | (code & 0x3f);
+                }
+            }
+            key = bytes;
+        }
+        else {
+            if (secretKey instanceof ArrayBuffer) {
+                key = new Uint8Array(secretKey);
+            }
+            else {
+                key = secretKey;
+            }
+        }
+        if (key.length > 64) {
+            key = new Sha256(is224, true).update(key).array();
+        }
+        const oKeyPad = [];
+        const iKeyPad = [];
+        for (let i = 0; i < 64; ++i) {
+            const b = key[i] || 0;
+            oKeyPad[i] = 0x5c ^ b;
+            iKeyPad[i] = 0x36 ^ b;
+        }
+        this.update(iKeyPad);
+        __classPrivateFieldSet(this, _HmacSha256_oKeyPad, oKeyPad, "f");
+        __classPrivateFieldSet(this, _HmacSha256_inner, true, "f");
+        __classPrivateFieldSet(this, _HmacSha256_is224, is224, "f");
+        __classPrivateFieldSet(this, _HmacSha256_sharedMemory, sharedMemory, "f");
+    }
+    finalize() {
+        super.finalize();
+        if (__classPrivateFieldGet(this, _HmacSha256_inner, "f")) {
+            __classPrivateFieldSet(this, _HmacSha256_inner, false, "f");
+            const innerHash = this.array();
+            super.init(__classPrivateFieldGet(this, _HmacSha256_is224, "f"), __classPrivateFieldGet(this, _HmacSha256_sharedMemory, "f"));
+            this.update(__classPrivateFieldGet(this, _HmacSha256_oKeyPad, "f"));
+            this.update(innerHash);
+            super.finalize();
+        }
+    }
+}
+_HmacSha256_inner = new WeakMap(), _HmacSha256_is224 = new WeakMap(), _HmacSha256_oKeyPad = new WeakMap(), _HmacSha256_sharedMemory = new WeakMap();
diff --git a/share/server/sha256.ts b/share/server/sha256.ts
new file mode 100755
index 000000000..a566f838a
--- /dev/null
+++ b/share/server/sha256.ts
@@ -0,0 +1,543 @@
+// Copyright 2018-2021 the Deno authors. All rights reserved. MIT license.
+/*
+ * Adapted to deno from:
+ *
+ * [js-sha256]{@link https://github.com/emn178/js-sha256}
+ *
+ * @version 0.9.0
+ * @author Chen, Yi-Cyuan [emn178@gmail.com]
+ * @copyright Chen, Yi-Cyuan 2014-2017
+ * @license MIT
+ */
+
+export type Message = string | number[] | ArrayBuffer;
+
+const HEX_CHARS = "0123456789abcdef".split("");
+const EXTRA = [-2147483648, 8388608, 32768, 128] as const;
+const SHIFT = [24, 16, 8, 0] as const;
+// deno-fmt-ignore
+const K = [
+  0x428a2f98, 0x71374491, 0xb5c0fbcf, 0xe9b5dba5, 0x3956c25b, 0x59f111f1,
+  0x923f82a4, 0xab1c5ed5, 0xd807aa98, 0x12835b01, 0x243185be, 0x550c7dc3,
+  0x72be5d74, 0x80deb1fe, 0x9bdc06a7, 0xc19bf174, 0xe49b69c1, 0xefbe4786,
+  0x0fc19dc6, 0x240ca1cc, 0x2de92c6f, 0x4a7484aa, 0x5cb0a9dc, 0x76f988da,
+  0x983e5152, 0xa831c66d, 0xb00327c8, 0xbf597fc7, 0xc6e00bf3, 0xd5a79147,
+  0x06ca6351, 0x14292967, 0x27b70a85, 0x2e1b2138, 0x4d2c6dfc, 0x53380d13,
+  0x650a7354, 0x766a0abb, 0x81c2c92e, 0x92722c85, 0xa2bfe8a1, 0xa81a664b,
+  0xc24b8b70, 0xc76c51a3, 0xd192e819, 0xd6990624, 0xf40e3585, 0x106aa070,
+  0x19a4c116, 0x1e376c08, 0x2748774c, 0x34b0bcb5, 0x391c0cb3, 0x4ed8aa4a,
+  0x5b9cca4f, 0x682e6ff3, 0x748f82ee, 0x78a5636f, 0x84c87814, 0x8cc70208,
+  0x90befffa, 0xa4506ceb, 0xbef9a3f7, 0xc67178f2,
+] as const;
+
+const blocks: number[] = [];
+
+export class Sha256 {
+  #block!: number;
+  #blocks!: number[];
+  #bytes!: number;
+  #finalized!: boolean;
+  #first!: boolean;
+  #h0!: number;
+  #h1!: number;
+  #h2!: number;
+  #h3!: number;
+  #h4!: number;
+  #h5!: number;
+  #h6!: number;
+  #h7!: number;
+  #hashed!: boolean;
+  #hBytes!: number;
+  #is224!: boolean;
+  #lastByteIndex = 0;
+  #start!: number;
+
+  constructor(is224 = false, sharedMemory = false) {
+    this.init(is224, sharedMemory);
+  }
+
+  protected init(is224: boolean, sharedMemory: boolean): void {
+    if (sharedMemory) {
+      // deno-fmt-ignore
+      blocks[0] = blocks[16] = blocks[1] = blocks[2] = blocks[3] = blocks[4] = blocks[5] = blocks[6] = blocks[7] = blocks[8] = blocks[9] = blocks[10] = blocks[11] = blocks[12] = blocks[13] = blocks[14] = blocks[15] = 0;
+      this.#blocks = blocks;
+    } else {
+      this.#blocks = [0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0];
+    }
+
+    if (is224) {
+      this.#h0 = 0xc1059ed8;
+      this.#h1 = 0x367cd507;
+      this.#h2 = 0x3070dd17;
+      this.#h3 = 0xf70e5939;
+      this.#h4 = 0xffc00b31;
+      this.#h5 = 0x68581511;
+      this.#h6 = 0x64f98fa7;
+      this.#h7 = 0xbefa4fa4;
+    } else {
+      // 256
+      this.#h0 = 0x6a09e667;
+      this.#h1 = 0xbb67ae85;
+      this.#h2 = 0x3c6ef372;
+      this.#h3 = 0xa54ff53a;
+      this.#h4 = 0x510e527f;
+      this.#h5 = 0x9b05688c;
+      this.#h6 = 0x1f83d9ab;
+      this.#h7 = 0x5be0cd19;
+    }
+
+    this.#block = this.#start = this.#bytes = this.#hBytes = 0;
+    this.#finalized = this.#hashed = false;
+    this.#first = true;
+    this.#is224 = is224;
+  }
+
+  /** Update hash
+   *
+   * @param message The message you want to hash.
+   */
+  update(message: Message): this {
+    if (this.#finalized) {
+      return this;
+    }
+
+    let msg: string | number[] | Uint8Array | undefined;
+    if (message instanceof ArrayBuffer) {
+      msg = new Uint8Array(message);
+    } else {
+      msg = message;
+    }
+
+    let index = 0;
+    const length = msg.length;
+    const blocks = this.#blocks;
+
+    while (index < length) {
+      let i: number;
+      if (this.#hashed) {
+        this.#hashed = false;
+        blocks[0] = this.#block;
+        // deno-fmt-ignore
+        blocks[16] = blocks[1] = blocks[2] = blocks[3] = blocks[4] = blocks[5] = blocks[6] = blocks[7] = blocks[8] = blocks[9] = blocks[10] = blocks[11] = blocks[12] = blocks[13] = blocks[14] = blocks[15] = 0;
+      }
+
+      if (typeof msg !== "string") {
+        for (i = this.#start; index < length && i < 64; ++index) {
+          blocks[i >> 2] |= msg[index] << SHIFT[i++ & 3];
+        }
+      } else {
+        for (i = this.#start; index < length && i < 64; ++index) {
+          let code = msg.charCodeAt(index);
+          if (code < 0x80) {
+            blocks[i >> 2] |= code << SHIFT[i++ & 3];
+          } else if (code < 0x800) {
+            blocks[i >> 2] |= (0xc0 | (code >> 6)) << SHIFT[i++ & 3];
+            blocks[i >> 2] |= (0x80 | (code & 0x3f)) << SHIFT[i++ & 3];
+          } else if (code < 0xd800 || code >= 0xe000) {
+            blocks[i >> 2] |= (0xe0 | (code >> 12)) << SHIFT[i++ & 3];
+            blocks[i >> 2] |= (0x80 | ((code >> 6) & 0x3f)) << SHIFT[i++ & 3];
+            blocks[i >> 2] |= (0x80 | (code & 0x3f)) << SHIFT[i++ & 3];
+          } else {
+            code = 0x10000 +
+              (((code & 0x3ff) << 10) | (msg.charCodeAt(++index) & 0x3ff));
+            blocks[i >> 2] |= (0xf0 | (code >> 18)) << SHIFT[i++ & 3];
+            blocks[i >> 2] |= (0x80 | ((code >> 12) & 0x3f)) << SHIFT[i++ & 3];
+            blocks[i >> 2] |= (0x80 | ((code >> 6) & 0x3f)) << SHIFT[i++ & 3];
+            blocks[i >> 2] |= (0x80 | (code & 0x3f)) << SHIFT[i++ & 3];
+          }
+        }
+      }
+
+      this.#lastByteIndex = i;
+      this.#bytes += i - this.#start;
+      if (i >= 64) {
+        this.#block = blocks[16];
+        this.#start = i - 64;
+        this.hash();
+        this.#hashed = true;
+      } else {
+        this.#start = i;
+      }
+    }
+    if (this.#bytes > 4294967295) {
+      this.#hBytes += (this.#bytes / 4294967296) << 0;
+      this.#bytes = this.#bytes % 4294967296;
+    }
+    return this;
+  }
+
+  protected finalize(): void {
+    if (this.#finalized) {
+      return;
+    }
+    this.#finalized = true;
+    const blocks = this.#blocks;
+    const i = this.#lastByteIndex;
+    blocks[16] = this.#block;
+    blocks[i >> 2] |= EXTRA[i & 3];
+    this.#block = blocks[16];
+    if (i >= 56) {
+      if (!this.#hashed) {
+        this.hash();
+      }
+      blocks[0] = this.#block;
+      // deno-fmt-ignore
+      blocks[16] = blocks[1] = blocks[2] = blocks[3] = blocks[4] = blocks[5] = blocks[6] = blocks[7] = blocks[8] = blocks[9] = blocks[10] = blocks[11] = blocks[12] = blocks[13] = blocks[14] = blocks[15] = 0;
+    }
+    blocks[14] = (this.#hBytes << 3) | (this.#bytes >>> 29);
+    blocks[15] = this.#bytes << 3;
+    this.hash();
+  }
+
+  protected hash(): void {
+    let a = this.#h0;
+    let b = this.#h1;
+    let c = this.#h2;
+    let d = this.#h3;
+    let e = this.#h4;
+    let f = this.#h5;
+    let g = this.#h6;
+    let h = this.#h7;
+    const blocks = this.#blocks;
+    let s0: number;
+    let s1: number;
+    let maj: number;
+    let t1: number;
+    let t2: number;
+    let ch: number;
+    let ab: number;
+    let da: number;
+    let cd: number;
+    let bc: number;
+
+    for (let j = 16; j < 64; ++j) {
+      // rightrotate
+      t1 = blocks[j - 15];
+      s0 = ((t1 >>> 7) | (t1 << 25)) ^ ((t1 >>> 18) | (t1 << 14)) ^ (t1 >>> 3);
+      t1 = blocks[j - 2];
+      s1 = ((t1 >>> 17) | (t1 << 15)) ^ ((t1 >>> 19) | (t1 << 13)) ^
+        (t1 >>> 10);
+      blocks[j] = (blocks[j - 16] + s0 + blocks[j - 7] + s1) << 0;
+    }
+
+    bc = b & c;
+    for (let j = 0; j < 64; j += 4) {
+      if (this.#first) {
+        if (this.#is224) {
+          ab = 300032;
+          t1 = blocks[0] - 1413257819;
+          h = (t1 - 150054599) << 0;
+          d = (t1 + 24177077) << 0;
+        } else {
+          ab = 704751109;
+          t1 = blocks[0] - 210244248;
+          h = (t1 - 1521486534) << 0;
+          d = (t1 + 143694565) << 0;
+        }
+        this.#first = false;
+      } else {
+        s0 = ((a >>> 2) | (a << 30)) ^
+          ((a >>> 13) | (a << 19)) ^
+          ((a >>> 22) | (a << 10));
+        s1 = ((e >>> 6) | (e << 26)) ^
+          ((e >>> 11) | (e << 21)) ^
+          ((e >>> 25) | (e << 7));
+        ab = a & b;
+        maj = ab ^ (a & c) ^ bc;
+        ch = (e & f) ^ (~e & g);
+        t1 = h + s1 + ch + K[j] + blocks[j];
+        t2 = s0 + maj;
+        h = (d + t1) << 0;
+        d = (t1 + t2) << 0;
+      }
+      s0 = ((d >>> 2) | (d << 30)) ^
+        ((d >>> 13) | (d << 19)) ^
+        ((d >>> 22) | (d << 10));
+      s1 = ((h >>> 6) | (h << 26)) ^
+        ((h >>> 11) | (h << 21)) ^
+        ((h >>> 25) | (h << 7));
+      da = d & a;
+      maj = da ^ (d & b) ^ ab;
+      ch = (h & e) ^ (~h & f);
+      t1 = g + s1 + ch + K[j + 1] + blocks[j + 1];
+      t2 = s0 + maj;
+      g = (c + t1) << 0;
+      c = (t1 + t2) << 0;
+      s0 = ((c >>> 2) | (c << 30)) ^
+        ((c >>> 13) | (c << 19)) ^
+        ((c >>> 22) | (c << 10));
+      s1 = ((g >>> 6) | (g << 26)) ^
+        ((g >>> 11) | (g << 21)) ^
+        ((g >>> 25) | (g << 7));
+      cd = c & d;
+      maj = cd ^ (c & a) ^ da;
+      ch = (g & h) ^ (~g & e);
+      t1 = f + s1 + ch + K[j + 2] + blocks[j + 2];
+      t2 = s0 + maj;
+      f = (b + t1) << 0;
+      b = (t1 + t2) << 0;
+      s0 = ((b >>> 2) | (b << 30)) ^
+        ((b >>> 13) | (b << 19)) ^
+        ((b >>> 22) | (b << 10));
+      s1 = ((f >>> 6) | (f << 26)) ^
+        ((f >>> 11) | (f << 21)) ^
+        ((f >>> 25) | (f << 7));
+      bc = b & c;
+      maj = bc ^ (b & d) ^ cd;
+      ch = (f & g) ^ (~f & h);
+      t1 = e + s1 + ch + K[j + 3] + blocks[j + 3];
+      t2 = s0 + maj;
+      e = (a + t1) << 0;
+      a = (t1 + t2) << 0;
+    }
+
+    this.#h0 = (this.#h0 + a) << 0;
+    this.#h1 = (this.#h1 + b) << 0;
+    this.#h2 = (this.#h2 + c) << 0;
+    this.#h3 = (this.#h3 + d) << 0;
+    this.#h4 = (this.#h4 + e) << 0;
+    this.#h5 = (this.#h5 + f) << 0;
+    this.#h6 = (this.#h6 + g) << 0;
+    this.#h7 = (this.#h7 + h) << 0;
+  }
+
+  /** Return hash in hex string. */
+  hex(): string {
+    this.finalize();
+
+    const h0 = this.#h0;
+    const h1 = this.#h1;
+    const h2 = this.#h2;
+    const h3 = this.#h3;
+    const h4 = this.#h4;
+    const h5 = this.#h5;
+    const h6 = this.#h6;
+    const h7 = this.#h7;
+
+    let hex = HEX_CHARS[(h0 >> 28) & 0x0f] +
+      HEX_CHARS[(h0 >> 24) & 0x0f] +
+      HEX_CHARS[(h0 >> 20) & 0x0f] +
+      HEX_CHARS[(h0 >> 16) & 0x0f] +
+      HEX_CHARS[(h0 >> 12) & 0x0f] +
+      HEX_CHARS[(h0 >> 8) & 0x0f] +
+      HEX_CHARS[(h0 >> 4) & 0x0f] +
+      HEX_CHARS[h0 & 0x0f] +
+      HEX_CHARS[(h1 >> 28) & 0x0f] +
+      HEX_CHARS[(h1 >> 24) & 0x0f] +
+      HEX_CHARS[(h1 >> 20) & 0x0f] +
+      HEX_CHARS[(h1 >> 16) & 0x0f] +
+      HEX_CHARS[(h1 >> 12) & 0x0f] +
+      HEX_CHARS[(h1 >> 8) & 0x0f] +
+      HEX_CHARS[(h1 >> 4) & 0x0f] +
+      HEX_CHARS[h1 & 0x0f] +
+      HEX_CHARS[(h2 >> 28) & 0x0f] +
+      HEX_CHARS[(h2 >> 24) & 0x0f] +
+      HEX_CHARS[(h2 >> 20) & 0x0f] +
+      HEX_CHARS[(h2 >> 16) & 0x0f] +
+      HEX_CHARS[(h2 >> 12) & 0x0f] +
+      HEX_CHARS[(h2 >> 8) & 0x0f] +
+      HEX_CHARS[(h2 >> 4) & 0x0f] +
+      HEX_CHARS[h2 & 0x0f] +
+      HEX_CHARS[(h3 >> 28) & 0x0f] +
+      HEX_CHARS[(h3 >> 24) & 0x0f] +
+      HEX_CHARS[(h3 >> 20) & 0x0f] +
+      HEX_CHARS[(h3 >> 16) & 0x0f] +
+      HEX_CHARS[(h3 >> 12) & 0x0f] +
+      HEX_CHARS[(h3 >> 8) & 0x0f] +
+      HEX_CHARS[(h3 >> 4) & 0x0f] +
+      HEX_CHARS[h3 & 0x0f] +
+      HEX_CHARS[(h4 >> 28) & 0x0f] +
+      HEX_CHARS[(h4 >> 24) & 0x0f] +
+      HEX_CHARS[(h4 >> 20) & 0x0f] +
+      HEX_CHARS[(h4 >> 16) & 0x0f] +
+      HEX_CHARS[(h4 >> 12) & 0x0f] +
+      HEX_CHARS[(h4 >> 8) & 0x0f] +
+      HEX_CHARS[(h4 >> 4) & 0x0f] +
+      HEX_CHARS[h4 & 0x0f] +
+      HEX_CHARS[(h5 >> 28) & 0x0f] +
+      HEX_CHARS[(h5 >> 24) & 0x0f] +
+      HEX_CHARS[(h5 >> 20) & 0x0f] +
+      HEX_CHARS[(h5 >> 16) & 0x0f] +
+      HEX_CHARS[(h5 >> 12) & 0x0f] +
+      HEX_CHARS[(h5 >> 8) & 0x0f] +
+      HEX_CHARS[(h5 >> 4) & 0x0f] +
+      HEX_CHARS[h5 & 0x0f] +
+      HEX_CHARS[(h6 >> 28) & 0x0f] +
+      HEX_CHARS[(h6 >> 24) & 0x0f] +
+      HEX_CHARS[(h6 >> 20) & 0x0f] +
+      HEX_CHARS[(h6 >> 16) & 0x0f] +
+      HEX_CHARS[(h6 >> 12) & 0x0f] +
+      HEX_CHARS[(h6 >> 8) & 0x0f] +
+      HEX_CHARS[(h6 >> 4) & 0x0f] +
+      HEX_CHARS[h6 & 0x0f];
+    if (!this.#is224) {
+      hex += HEX_CHARS[(h7 >> 28) & 0x0f] +
+        HEX_CHARS[(h7 >> 24) & 0x0f] +
+        HEX_CHARS[(h7 >> 20) & 0x0f] +
+        HEX_CHARS[(h7 >> 16) & 0x0f] +
+        HEX_CHARS[(h7 >> 12) & 0x0f] +
+        HEX_CHARS[(h7 >> 8) & 0x0f] +
+        HEX_CHARS[(h7 >> 4) & 0x0f] +
+        HEX_CHARS[h7 & 0x0f];
+    }
+    return hex;
+  }
+
+  /** Return hash in hex string. */
+  toString(): string {
+    return this.hex();
+  }
+
+  /** Return hash in integer array. */
+  digest(): number[] {
+    this.finalize();
+
+    const h0 = this.#h0;
+    const h1 = this.#h1;
+    const h2 = this.#h2;
+    const h3 = this.#h3;
+    const h4 = this.#h4;
+    const h5 = this.#h5;
+    const h6 = this.#h6;
+    const h7 = this.#h7;
+
+    const arr = [
+      (h0 >> 24) & 0xff,
+      (h0 >> 16) & 0xff,
+      (h0 >> 8) & 0xff,
+      h0 & 0xff,
+      (h1 >> 24) & 0xff,
+      (h1 >> 16) & 0xff,
+      (h1 >> 8) & 0xff,
+      h1 & 0xff,
+      (h2 >> 24) & 0xff,
+      (h2 >> 16) & 0xff,
+      (h2 >> 8) & 0xff,
+      h2 & 0xff,
+      (h3 >> 24) & 0xff,
+      (h3 >> 16) & 0xff,
+      (h3 >> 8) & 0xff,
+      h3 & 0xff,
+      (h4 >> 24) & 0xff,
+      (h4 >> 16) & 0xff,
+      (h4 >> 8) & 0xff,
+      h4 & 0xff,
+      (h5 >> 24) & 0xff,
+      (h5 >> 16) & 0xff,
+      (h5 >> 8) & 0xff,
+      h5 & 0xff,
+      (h6 >> 24) & 0xff,
+      (h6 >> 16) & 0xff,
+      (h6 >> 8) & 0xff,
+      h6 & 0xff,
+    ];
+    if (!this.#is224) {
+      arr.push(
+        (h7 >> 24) & 0xff,
+        (h7 >> 16) & 0xff,
+        (h7 >> 8) & 0xff,
+        h7 & 0xff,
+      );
+    }
+    return arr;
+  }
+
+  /** Return hash in integer array. */
+  array(): number[] {
+    return this.digest();
+  }
+
+  /** Return hash in ArrayBuffer. */
+  arrayBuffer(): ArrayBuffer {
+    this.finalize();
+
+    const buffer = new ArrayBuffer(this.#is224 ? 28 : 32);
+    const dataView = new DataView(buffer);
+    dataView.setUint32(0, this.#h0);
+    dataView.setUint32(4, this.#h1);
+    dataView.setUint32(8, this.#h2);
+    dataView.setUint32(12, this.#h3);
+    dataView.setUint32(16, this.#h4);
+    dataView.setUint32(20, this.#h5);
+    dataView.setUint32(24, this.#h6);
+    if (!this.#is224) {
+      dataView.setUint32(28, this.#h7);
+    }
+    return buffer;
+  }
+}
+
+export class HmacSha256 extends Sha256 {
+  #inner: boolean;
+  #is224: boolean;
+  #oKeyPad: number[];
+  #sharedMemory: boolean;
+
+  constructor(secretKey: Message, is224 = false, sharedMemory = false) {
+    super(is224, sharedMemory);
+
+    let key: number[] | Uint8Array | undefined;
+    if (typeof secretKey === "string") {
+      const bytes: number[] = [];
+      const length = secretKey.length;
+      let index = 0;
+      for (let i = 0; i < length; ++i) {
+        let code = secretKey.charCodeAt(i);
+        if (code < 0x80) {
+          bytes[index++] = code;
+        } else if (code < 0x800) {
+          bytes[index++] = 0xc0 | (code >> 6);
+          bytes[index++] = 0x80 | (code & 0x3f);
+        } else if (code < 0xd800 || code >= 0xe000) {
+          bytes[index++] = 0xe0 | (code >> 12);
+          bytes[index++] = 0x80 | ((code >> 6) & 0x3f);
+          bytes[index++] = 0x80 | (code & 0x3f);
+        } else {
+          code = 0x10000 +
+            (((code & 0x3ff) << 10) | (secretKey.charCodeAt(++i) & 0x3ff));
+          bytes[index++] = 0xf0 | (code >> 18);
+          bytes[index++] = 0x80 | ((code >> 12) & 0x3f);
+          bytes[index++] = 0x80 | ((code >> 6) & 0x3f);
+          bytes[index++] = 0x80 | (code & 0x3f);
+        }
+      }
+      key = bytes;
+    } else {
+      if (secretKey instanceof ArrayBuffer) {
+        key = new Uint8Array(secretKey);
+      } else {
+        key = secretKey;
+      }
+    }
+
+    if (key.length > 64) {
+      key = new Sha256(is224, true).update(key).array();
+    }
+
+    const oKeyPad: number[] = [];
+    const iKeyPad: number[] = [];
+    for (let i = 0; i < 64; ++i) {
+      const b = key[i] || 0;
+      oKeyPad[i] = 0x5c ^ b;
+      iKeyPad[i] = 0x36 ^ b;
+    }
+
+    this.update(iKeyPad);
+    this.#oKeyPad = oKeyPad;
+    this.#inner = true;
+    this.#is224 = is224;
+    this.#sharedMemory = sharedMemory;
+  }
+
+  protected finalize(): void {
+    super.finalize();
+    if (this.#inner) {
+      this.#inner = false;
+      const innerHash = this.array();
+      super.init(this.#is224, this.#sharedMemory);
+      this.update(this.#oKeyPad);
+      this.update(innerHash);
+      super.finalize();
+    }
+  }
+}
diff --git a/share/server/state.js b/share/server/state.js
index ff553dd57..71ab48e05 100644
--- a/share/server/state.js
+++ b/share/server/state.js
@@ -22,10 +22,12 @@ var State = {
   addFun : function(newFun) {
     // Compile to a function and add it to funs array
     State.funs.push(Couch.compileFunction(newFun, {views : {lib : State.lib}}));
+    State.cache = {}; // reset cache only when we add new map funs
     print("true");
   },
   addLib : function(lib) {
     State.lib = lib;
     print("true");
-  }
+  },
+  cache: {}
 };
diff --git a/support/build_js.escript b/support/build_js.escript
index 5f1e92015..68a44297e 100644
--- a/support/build_js.escript
+++ b/support/build_js.escript
@@ -34,6 +34,7 @@ main([]) ->
     end,
 
     JsFiles =  [
+        "share/server/sha256.js",
         "share/server/json2.js",
         "share/server/dreyfus.js",
         "share/server/filter.js",
@@ -47,6 +48,7 @@ main([]) ->
     ],
 
     CoffeeFiles = [
+        "share/server/sha256.js",
         "share/server/json2.js",
         "share/server/dreyfus.js",
         "share/server/filter.js",