1. Construct a JWT header with this format: {"alg":"RS256"}.
2. Base64url encode the JWT header as defined in http://tools.ietf.org/html/rfc4648#page-7. The result issimilar to eyJhbGciOiJSUzI1NiJ9.
3. Construct a JSON Claims Set for the JWT with iss, sub, aud,and exp.{"iss": "3MVG99OxTyEMCQ3gNp2PjkqeZKxnmAiG1xV4oHh9AKL_rSK.BoSVPGZHQukXnVjzRgSuQqGn75NL7yfkQcyy7", "sub": "my@email.com", "aud": "https://login.salesforce.com", "exp": "1333685628"}
4. Base64url encode the JWT Claims Set without any line breaks. For example:eyJpc3MiOiAiM01WRzk5T3hUeUVNQ1EzZ05wMlBqa3FlWkt4bm1BaUcxeFY0b0hoOUFLTF9yU0suQm9TVlBHWkhRdWtYblZqelJnU3VRcUduNzVOTDd5ZmtRY3l5NyIsICJwcm4iOiAibXlAZW1haWwuY29tIiwgImF1ZCI6ICJodHRwczovL2xvZ2luLnNhbGVzZm9yY2UuY29tIiwgImV4cCI6ICIxMzMzNjg1NjI4In0=
5. Create a string for the encoded JWT Header and the encodedJWT Claims Set in thisformat.encoded_JWT_Header + "." + encoded_JWT_Claims_SetInthe following example, the encoded JWT Header ishighlighted.eyJhbGciOiJSUzI1NiJ9.eyJpc3MiOiAiM01WRzk5T3hUeUVNQ1EzZ05wMlBqa3FlWkt4bm1BaUcxeFY0b0hoOUFLTF9yU0suQm9TVlBHWkhRdWtYblZqelJnU3VRcUduNzVOTDd5ZmtRY3l5NyIsICJwcm4iOiAibXlAZW1haWwuY29tIiwgImF1ZCI6ICJodHRwczovL2xvZ2luLnNhbGVzZm9yY2UuY29tIiwgImV4cCI6ICIxMzMzNjg1NjI4In0=
6. Sign the resulting string using SHA256 with RSA.
7. Create a string of the string from this step in the followingformat.existing_string + "." + base64_encoded_signatureInthe following example, the start of the base64 encoded signature ishighlighted.eyJhbGciOiJSUzI1NiJ9.eyJpc3MiOiAiM01WRzk5T3hUeUVNQ1EzZ05wMlBqa3FlWkt4bm1BaUcxeFY0b0hoOUFLTF9yU0suQm9TVlBHWkhRdWtYblZqelJnU3VRcUduNzVOTDd5ZmtRY3l5NyIsICJwcm4iOiAibXlAZW1haWwuY29tIiwgImF1ZCI6ICJodHRwczovL2xvZ2luLnNhbGVzZm9yY2UuY29tIiwgImV4cCI6ICIxMzMzNjg1NjI4In0=.iYCthqWCQucwi35yFs-nWNgpF5NA_a46fXDTNIY8ACko6BaEtQ9E6h4Hn1l_pcwcK​I_GlmfUO2dJDg1A610t09TeoPagJsZDm_H83bsoZUoI8LpAA1s-2aj_Wbysqb1j4uDToz​480WtEbkwIv09sIeS_-QuWak2RXOl1Krnf72mpVGS4WWSULodgNzlKHHyjAMAHiBHIDNt​36y2L2Bh7M8TNWiKa_BNM6s1FNKDAwHEWQrNtAeReXgRy0MZgQY2rZtqT2FcDyjY3JVQb​En_CSjH2WV7ZlUwsKHqGfI7hzeEvVdfOjH9NuaJozxvhPF489IgW6cntPuT2V647JWi7ng