diff --git a/LICENSE b/LICENSE
index 048ee41..9ab8743 100644
--- a/LICENSE
+++ b/LICENSE
@@ -2267,3 +2267,25 @@
 (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 8fd1bef..8c8554c 100644
--- a/NOTICE
+++ b/NOTICE
@@ -197,3 +197,8 @@
 * 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 1b27a9d..8ebae3f 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 @@
     }
 
     // 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 0000000..6c6a98f
--- /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 0000000..a566f83
--- /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 ff553dd..71ab48e 100644
--- a/share/server/state.js
+++ b/share/server/state.js
@@ -22,10 +22,12 @@
   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 5f1e920..68a4429 100644
--- a/support/build_js.escript
+++ b/support/build_js.escript
@@ -34,6 +34,7 @@
     end,
 
     JsFiles =  [
+        "share/server/sha256.js",
         "share/server/json2.js",
         "share/server/dreyfus.js",
         "share/server/filter.js",
@@ -47,6 +48,7 @@
     ],
 
     CoffeeFiles = [
+        "share/server/sha256.js",
         "share/server/json2.js",
         "share/server/dreyfus.js",
         "share/server/filter.js",