Crypto_MCP

Instructions

Implementation Reference

• src/service/des.ts:495-540 (handler)

  The main handler function for the 'des_decrypt' tool. It dispatches to the appropriate DESUtil.decrypt* method based on the 'mode' parameter (ECB, CBC, CFB, OFB, CTR) and returns the decrypted text.

  async ({ content, key, iv, padding, inputFormat, mode }) => {
    let result = "";
    if (mode === "ECB") {
      result = DESUtil.decryptECB(content, key ?? "your-key");
    } else if (mode === "CBC") {
      result = DESUtil.decryptCBC(
        content,
        key ?? "your-key",
        iv ?? "your-iv-",
        (padding ?? "Pkcs7") as PaddingMode,
        (inputFormat ?? "base64") as OutputFormat
      );
    } else if (mode === "CFB") {
      result = DESUtil.decryptCFB(
        content,
        key ?? "your-key",
        iv ?? "your-iv-",
        (padding ?? "Pkcs7") as PaddingMode,
        (inputFormat ?? "base64") as OutputFormat
      );
    } else if (mode === "OFB") {
      result = DESUtil.decryptOFB(
        content,
        key ?? "your-key",
        iv ?? "your-iv-",
        (padding ?? "Pkcs7") as PaddingMode,
        (inputFormat ?? "base64") as OutputFormat
      );
    } else if (mode === "CTR") {
      result = DESUtil.decryptCTR(
        content,
        key ?? "your-key",
        iv ?? "your-iv-",
        (padding ?? "Pkcs7") as PaddingMode,
        (inputFormat ?? "base64") as OutputFormat
      );
    }
    return {
      content: [
        {
          type: "text",
          text: result,
        },
      ],
    };
  }

• src/service/des.ts:461-494 (schema)

  Zod schema for input validation of the 'des_decrypt' tool parameters: content (encrypted text), key, iv, padding, inputFormat, and mode.

  {
    content: z.string().describe("text to decrypt"),
    key: z
      .string()
      .optional()
      .describe("decryption key, default is your-key"),
    iv: z
      .string()
      .optional()
      .describe("initialization vector, default is your-iv-")
      .default("your-iv-"),
    padding: z
      .enum([
        "Pkcs7",
        "Iso97971",
        "AnsiX923",
        "Iso10126",
        "ZeroPadding",
        "NoPadding",
      ])
      .optional()
      .describe("padding mode, default is Pkcs7")
      .default("Pkcs7"),
    inputFormat: z
      .enum(["base64", "hex"])
      .optional()
      .describe("input format, default is base64")
      .default("base64"),
    mode: z
      .enum(["ECB", "CBC", "CFB", "OFB", "CTR"])
      .optional()
      .describe("mode, default is ECB")
      .default("ECB"),
  },

• src/service/des.ts:458-541 (registration)

  The server.tool registration for the 'des_decrypt' tool, including name, description, schema, and handler.

  server.tool(
    "des_decrypt",
    "decrypt text with des",
    {
      content: z.string().describe("text to decrypt"),
      key: z
        .string()
        .optional()
        .describe("decryption key, default is your-key"),
      iv: z
        .string()
        .optional()
        .describe("initialization vector, default is your-iv-")
        .default("your-iv-"),
      padding: z
        .enum([
          "Pkcs7",
          "Iso97971",
          "AnsiX923",
          "Iso10126",
          "ZeroPadding",
          "NoPadding",
        ])
        .optional()
        .describe("padding mode, default is Pkcs7")
        .default("Pkcs7"),
      inputFormat: z
        .enum(["base64", "hex"])
        .optional()
        .describe("input format, default is base64")
        .default("base64"),
      mode: z
        .enum(["ECB", "CBC", "CFB", "OFB", "CTR"])
        .optional()
        .describe("mode, default is ECB")
        .default("ECB"),
    },
    async ({ content, key, iv, padding, inputFormat, mode }) => {
      let result = "";
      if (mode === "ECB") {
        result = DESUtil.decryptECB(content, key ?? "your-key");
      } else if (mode === "CBC") {
        result = DESUtil.decryptCBC(
          content,
          key ?? "your-key",
          iv ?? "your-iv-",
          (padding ?? "Pkcs7") as PaddingMode,
          (inputFormat ?? "base64") as OutputFormat
        );
      } else if (mode === "CFB") {
        result = DESUtil.decryptCFB(
          content,
          key ?? "your-key",
          iv ?? "your-iv-",
          (padding ?? "Pkcs7") as PaddingMode,
          (inputFormat ?? "base64") as OutputFormat
        );
      } else if (mode === "OFB") {
        result = DESUtil.decryptOFB(
          content,
          key ?? "your-key",
          iv ?? "your-iv-",
          (padding ?? "Pkcs7") as PaddingMode,
          (inputFormat ?? "base64") as OutputFormat
        );
      } else if (mode === "CTR") {
        result = DESUtil.decryptCTR(
          content,
          key ?? "your-key",
          iv ?? "your-iv-",
          (padding ?? "Pkcs7") as PaddingMode,
          (inputFormat ?? "base64") as OutputFormat
        );
      }
      return {
        content: [
          {
            type: "text",
            text: result,
          },
        ],
      };
    }
  );

• src/service/des.ts:50-76 (helper)

  DESUtil.decryptECB: Helper function for ECB mode decryption, called by the handler when mode='ECB' (default). Uses CryptoJS.DES.decrypt.

  static decryptECB(
    ciphertext: string,
    key: string,
    padding: PaddingMode = "Pkcs7",
    inputFormat: OutputFormat = "base64"
  ): string {
    const keyHex = CryptoJS.enc.Utf8.parse(key);
    let decrypted;
  
    if (inputFormat === "hex") {
      const ciphertextHex = CryptoJS.enc.Hex.parse(ciphertext);
      const ciphertextParams = CryptoJS.lib.CipherParams.create({
        ciphertext: ciphertextHex,
      });
      decrypted = CryptoJS.DES.decrypt(ciphertextParams, keyHex, {
        mode: CryptoJS.mode.ECB,
        padding: CryptoJS.pad[padding],
      });
    } else {
      decrypted = CryptoJS.DES.decrypt(ciphertext, keyHex, {
        mode: CryptoJS.mode.ECB,
        padding: CryptoJS.pad[padding],
      });
    }
  
    return decrypted.toString(CryptoJS.enc.Utf8);
  }

• src/index.ts:17-17 (registration)

  Top-level call to registerDESTool, which registers the 'des_decrypt' tool among others.

  registerDESTool(server);