1 files changed, 157 insertions, 0 deletions
diff --git a/cli/rt/07_base64.js b/cli/rt/07_base64.js
new file mode 100644
index 000000000..7e7f5ca78
--- /dev/null
+++ b/cli/rt/07_base64.js
@@ -0,0 +1,157 @@
+// Copyright 2018-2020 the Deno authors. All rights reserved. MIT license.
+
+// Forked from https://github.com/beatgammit/base64-js
+// Copyright (c) 2014 Jameson Little. MIT License.
+
+((window) => {
+  const lookup = [];
+  const revLookup = [];
+
+  const code =
+    "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
+  for (let i = 0, len = code.length; i < len; ++i) {
+    lookup[i] = code[i];
+    revLookup[code.charCodeAt(i)] = i;
+  }
+
+  // Support decoding URL-safe base64 strings, as Node.js does.
+  // See: https://en.wikipedia.org/wiki/Base64#URL_applications
+  revLookup["-".charCodeAt(0)] = 62;
+  revLookup["_".charCodeAt(0)] = 63;
+
+  function getLens(b64) {
+    const len = b64.length;
+
+    if (len % 4 > 0) {
+      throw new Error("Invalid string. Length must be a multiple of 4");
+    }
+
+    // Trim off extra bytes after placeholder bytes are found
+    // See: https://github.com/beatgammit/base64-js/issues/42
+    let validLen = b64.indexOf("=");
+    if (validLen === -1) validLen = len;
+
+    const placeHoldersLen = validLen === len ? 0 : 4 - (validLen % 4);
+
+    return [validLen, placeHoldersLen];
+  }
+
+  // base64 is 4/3 + up to two characters of the original data
+  function byteLength(b64) {
+    const lens = getLens(b64);
+    const validLen = lens[0];
+    const placeHoldersLen = lens[1];
+    return ((validLen + placeHoldersLen) * 3) / 4 - placeHoldersLen;
+  }
+
+  function _byteLength(
+    b64,
+    validLen,
+    placeHoldersLen,
+  ) {
+    return ((validLen + placeHoldersLen) * 3) / 4 - placeHoldersLen;
+  }
+
+  function toByteArray(b64) {
+    let tmp;
+    const lens = getLens(b64);
+    const validLen = lens[0];
+    const placeHoldersLen = lens[1];
+
+    const arr = new Uint8Array(_byteLength(b64, validLen, placeHoldersLen));
+
+    let curByte = 0;
+
+    // if there are placeholders, only get up to the last complete 4 chars
+    const len = placeHoldersLen > 0 ? validLen - 4 : validLen;
+
+    let i;
+    for (i = 0; i < len; i += 4) {
+      tmp = (revLookup[b64.charCodeAt(i)] << 18) |
+        (revLookup[b64.charCodeAt(i + 1)] << 12) |
+        (revLookup[b64.charCodeAt(i + 2)] << 6) |
+        revLookup[b64.charCodeAt(i + 3)];
+      arr[curByte++] = (tmp >> 16) & 0xff;
+      arr[curByte++] = (tmp >> 8) & 0xff;
+      arr[curByte++] = tmp & 0xff;
+    }
+
+    if (placeHoldersLen === 2) {
+      tmp = (revLookup[b64.charCodeAt(i)] << 2) |
+        (revLookup[b64.charCodeAt(i + 1)] >> 4);
+      arr[curByte++] = tmp & 0xff;
+    }
+
+    if (placeHoldersLen === 1) {
+      tmp = (revLookup[b64.charCodeAt(i)] << 10) |
+        (revLookup[b64.charCodeAt(i + 1)] << 4) |
+        (revLookup[b64.charCodeAt(i + 2)] >> 2);
+      arr[curByte++] = (tmp >> 8) & 0xff;
+      arr[curByte++] = tmp & 0xff;
+    }
+
+    return arr;
+  }
+
+  function tripletToBase64(num) {
+    return (
+      lookup[(num >> 18) & 0x3f] +
+      lookup[(num >> 12) & 0x3f] +
+      lookup[(num >> 6) & 0x3f] +
+      lookup[num & 0x3f]
+    );
+  }
+
+  function encodeChunk(uint8, start, end) {
+    let tmp;
+    const output = [];
+    for (let i = start; i < end; i += 3) {
+      tmp = ((uint8[i] << 16) & 0xff0000) +
+        ((uint8[i + 1] << 8) & 0xff00) +
+        (uint8[i + 2] & 0xff);
+      output.push(tripletToBase64(tmp));
+    }
+    return output.join("");
+  }
+
+  function fromByteArray(uint8) {
+    let tmp;
+    const len = uint8.length;
+    const extraBytes = len % 3; // if we have 1 byte left, pad 2 bytes
+    const parts = [];
+    const maxChunkLength = 16383; // must be multiple of 3
+
+    // go through the array every three bytes, we'll deal with trailing stuff later
+    for (let i = 0, len2 = len - extraBytes; i < len2; i += maxChunkLength) {
+      parts.push(
+        encodeChunk(
+          uint8,
+          i,
+          i + maxChunkLength > len2 ? len2 : i + maxChunkLength,
+        ),
+      );
+    }
+
+    // pad the end with zeros, but make sure to not forget the extra bytes
+    if (extraBytes === 1) {
+      tmp = uint8[len - 1];
+      parts.push(lookup[tmp >> 2] + lookup[(tmp << 4) & 0x3f] + "==");
+    } else if (extraBytes === 2) {
+      tmp = (uint8[len - 2] << 8) + uint8[len - 1];
+      parts.push(
+        lookup[tmp >> 10] +
+          lookup[(tmp >> 4) & 0x3f] +
+          lookup[(tmp << 2) & 0x3f] +
+          "=",
+      );
+    }
+
+    return parts.join("");
+  }
+
+  window.__base64 = {
+    byteLength,
+    toByteArray,
+    fromByteArray,
+  };
+})(this);