How to create mail signature jwt

A mail signature JWT (JSON Web Token) is a digital signature that can be added to an email message to verify its authenticity and integrity. Here's a step-by-step guide on how to create a mail signature JWT:

Prerequisites:

You have a private key (e.g., RSA or ECDSA) to sign the JWT.
You have a public key (e.g., RSA or ECDSA) to verify the JWT.
You have a JSON Web Token (JWT) library or implementation for your programming language of choice.

Step 1: Create a JSON payload

Create a JSON object that contains the information you want to include in the mail signature. This can include:

Your name
Your email address
A timestamp
Any other relevant information

Example JSON payload:

{
  "name": "John Doe",
  "email": "[email protected]",
  "timestamp": 1643723400
}

Step 2: Create a JWT header

Create a JWT header that specifies the algorithm used to sign the JWT and the type of token. For example:

{
  "alg": "RS256",
  "typ": "JWT"
}

Step 3: Create a JWT payload

Combine the JSON payload and the JWT header to create a JWT payload. Use the . character to separate the header and payload.

Example JWT payload:

eyJhbGciOiJSUzI1NiIsInR5cCI6IkpXVCJ9.eyJmb3JtIjoiSm9obiBEYXRhIiwiZW1haWwiOiJqb2huQGV4YW1wbGUuY29tIiwiZXhwIjoxNjQzNzIzNDAwfQ==

Step 4: Sign the JWT

Use your private key to sign the JWT payload. This will create a digital signature that can be used to verify the authenticity of the JWT.

Example signing using OpenSSL:

openssl dgst -sha256 -sign private_key.pem -out signature -binary < jwt_payload.json

Step 5: Add the JWT to the email signature

Add the signed JWT to the email signature. You can do this by including the JWT in the Content-Type header or as a separate attachment.

Example email signature:

Content-Type: application/jwt
X-JWT-Signature: eyJhbGciOiJSUzI1NiIsInR5cCI6IkpXVCJ9.eyJmb3JtIjoiSm9obiBEYXRhIiwiZW1haWwiOiJqb2huQGV4YW1wbGUuY29tIiwiZXhwIjoxNjQzNzIzNDAwfQ==

Step 6: Verify the JWT

When the email is received, use the public key to verify the JWT signature. If the signature is valid, you can trust the authenticity and integrity of the email.

Example verification using OpenSSL:

openssl dgst -sha256 -verify public_key.pem -signature signature -binary < jwt_payload.json

That's it! You have now created a mail signature JWT.

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How to create mail signature jwt