Anatomy of a JSON Web Token (JWT)

JWT_Anatomy.txt

//header

{
  "alg": "HS256",
  "typ": "JWT"
}

//payload/claims

{
  "sub": "1234567890",
  "name": "John Doe",
  "admin": true
}

//the formula

encoded_part = base64Of(header) + "." base64Of(payload)
signature = signedUsingHS256WithSecret(encoded_part) //assume that algo is HS256 and secret key is 'secret'
JWT = encoded_part + "." + sigature

//the JWT ( notice the separator/period --> "." )

eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9 //base-64 encoded header
.eyJzdWIiOiIxMjM0NTY3ODkwIiwibmFtZSI6IkpvaG4gRG9lIiwiYWRtaW4iOnRydWV9 //base-64 encoded payload
.TJVA95OrM7E2cBab30RMHrHDcEfxjoYZgeFONFh7HgQ //the signature