Security

Digital Signature Generator

Sign a message with a private key or verify a signature with a public key — supports RSA-PSS (SHA-256), ECDSA (P-256), and Ed25519. Pure client-side crypto (Node crypto.createSign/createVerify), no network. Paste a PEM key to sign or to verify a base64 signature. This tool signs/verifies; it does not generate key pairs.

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Quick start

Call this tool from your code in three languages.

cURL

curl -X POST 'https://api.elysiatools.com/en/api/tools/digital-signature-generator' \
  -H 'Content-Type: application/json' \
  -d '{"mode":"sign","algorithm":"ed25519","message":"This document is authentic.","privateKey":"-----BEGIN PRIVATE KEY-----\nMC4CAQAwBQYDK2VwBCIEILoP...\n-----END PRIVATE KEY-----","publicKey":"-----BEGIN PUBLIC KEY-----\n...\n-----END PUBLIC KEY-----\n\n(Used in Verify mode.)","signature":"Paste the base64 signature to verify. (Used in Verify mode.)"}'

API reference

Send a POST request with your inputs as JSON. File parameters require a separate upload first.

Endpoint

HTTP

POST https://api.elysiatools.com/en/api/tools/digital-signature-generator

Parameters

Name	Type	Required	Description
mode	select	No	—
algorithm	select	No	—
message	textarea	Yes	—
privateKey	textarea	No	—
publicKey	textarea	No	—
signature

MCP integration

Add this tool to your Model Context Protocol server so AI agents can list and call it.

Server configuration

Add this block to your MCP client configuration:

mcp.json

{
  "mcpServers": {
    "elysiatools-digital-signature-generator": {
      "name": "digital-signature-generator",
      "description": "Sign a message with a private key or verify a signature with a public key — supports RSA-PSS (SHA-256), ECDSA (P-256), and Ed25519. Pure client-side crypto (Node crypto.createSign/createVerify), no network. Paste a PEM key to sign or to verify a base64 signature. This tool signs/verifies; it does not generate key pairs.",
      "baseUrl": "https://api.elysiatools.com/mcp/sse?toolId=digital-signature-generator",
      "command": "",
      "args": [],
      "env": {},
      "isActive": true,
      "type": "sse"
    }
  }
}

List available tools

After connecting to the SSE endpoint, list the exposed tools:

tools/list

{
  "jsonrpc": "2.0",
  "id": 1,
  "method": "tools/list"
}

Call this tool

Invoke the tool by its id, passing arguments built from its parameters:

tools/call

{
  "jsonrpc": "2.0",
  "id": 2,
  "method": "tools/call",
  "params": {
    "name": "digital-signature-generator",
    "arguments": {
  "mode": "sign",
  "algorithm": "ed25519",
  "message": "This document is authentic.",
  "privateKey": "-----BEGIN PRIVATE KEY-----\nMC4CAQAwBQYDK2VwBCIEILoP...\n-----END PRIVATE KEY-----",
  "publicKey": "-----BEGIN PUBLIC KEY-----\n...\n-----END PUBLIC KEY-----\n\n(Used in Verify mode.)",
  "signature": "Paste the base64 signature to verify. (Used in Verify mode.)"
}
  }
}