1 files changed, 97 insertions, 0 deletions
diff --git a/node_modules/mysql2/lib/packets/change_user.js b/node_modules/mysql2/lib/packets/change_user.js
new file mode 100644
index 0000000..3fa3937
--- /dev/null
+++ b/node_modules/mysql2/lib/packets/change_user.js
@@ -0,0 +1,97 @@
+'use strict';
+
+const CommandCode = require('../constants/commands.js');
+const ClientConstants = require('../constants/client.js');
+const Packet = require('../packets/packet.js');
+const auth41 = require('../auth_41.js');
+const CharsetToEncoding = require('../constants/charset_encodings.js');
+
+// https://dev.mysql.com/doc/internals/en/com-change-user.html#packet-COM_CHANGE_USER
+class ChangeUser {
+  constructor(opts) {
+    this.flags = opts.flags;
+    this.user = opts.user || '';
+    this.database = opts.database || '';
+    this.password = opts.password || '';
+    this.passwordSha1 = opts.passwordSha1;
+    this.authPluginData1 = opts.authPluginData1;
+    this.authPluginData2 = opts.authPluginData2;
+    this.connectAttributes = opts.connectAttrinutes || {};
+    let authToken;
+    if (this.passwordSha1) {
+      authToken = auth41.calculateTokenFromPasswordSha(
+        this.passwordSha1,
+        this.authPluginData1,
+        this.authPluginData2
+      );
+    } else {
+      authToken = auth41.calculateToken(
+        this.password,
+        this.authPluginData1,
+        this.authPluginData2
+      );
+    }
+    this.authToken = authToken;
+    this.charsetNumber = opts.charsetNumber;
+  }
+
+  // TODO
+  // ChangeUser.fromPacket = function(packet)
+  // };
+  serializeToBuffer(buffer) {
+    const isSet = flag => this.flags & ClientConstants[flag];
+    const packet = new Packet(0, buffer, 0, buffer.length);
+    packet.offset = 4;
+    const encoding = CharsetToEncoding[this.charsetNumber];
+    packet.writeInt8(CommandCode.CHANGE_USER);
+    packet.writeNullTerminatedString(this.user, encoding);
+    if (isSet('SECURE_CONNECTION')) {
+      packet.writeInt8(this.authToken.length);
+      packet.writeBuffer(this.authToken);
+    } else {
+      packet.writeBuffer(this.authToken);
+      packet.writeInt8(0);
+    }
+    packet.writeNullTerminatedString(this.database, encoding);
+    packet.writeInt16(this.charsetNumber);
+    if (isSet('PLUGIN_AUTH')) {
+      // TODO: read this from parameters
+      packet.writeNullTerminatedString('mysql_native_password', 'latin1');
+    }
+    if (isSet('CONNECT_ATTRS')) {
+      const connectAttributes = this.connectAttributes;
+      const attrNames = Object.keys(connectAttributes);
+      let keysLength = 0;
+      for (let k = 0; k < attrNames.length; ++k) {
+        keysLength += Packet.lengthCodedStringLength(attrNames[k], encoding);
+        keysLength += Packet.lengthCodedStringLength(
+          connectAttributes[attrNames[k]],
+          encoding
+        );
+      }
+      packet.writeLengthCodedNumber(keysLength);
+      for (let k = 0; k < attrNames.length; ++k) {
+        packet.writeLengthCodedString(attrNames[k], encoding);
+        packet.writeLengthCodedString(
+          connectAttributes[attrNames[k]],
+          encoding
+        );
+      }
+    }
+    return packet;
+  }
+
+  toPacket() {
+    if (typeof this.user !== 'string') {
+      throw new Error('"user" connection config property must be a string');
+    }
+    if (typeof this.database !== 'string') {
+      throw new Error('"database" connection config property must be a string');
+    }
+    // dry run: calculate resulting packet length
+    const p = this.serializeToBuffer(Packet.MockBuffer());
+    return this.serializeToBuffer(Buffer.allocUnsafe(p.offset));
+  }
+}
+
+module.exports = ChangeUser;