Go Requires Chilkat v11.0.0+

Validate a JWS Using ECDSA P-521 SHA-512

See more JSON Web Signatures (JWS) Examples

Validates a JSON Web Signature (JWS) that uses ECDSA P-521 SHA-512 Go

    success := false

    //  This requires the Chilkat API to have been previously unlocked.
    //  See Global Unlock Sample for sample code.

    //  This example takes a JSON signature in compact serialization format,
    //  and uses an ECDSA public key to validate and recover the protected header and payload.

    //  We only need a public key for signature validation.  This is the ECDSA public key
    //  that is used:

    //       {"kty":"EC", 
    //        "crv":"P-521", 
    //        "x":"AekpBQ8ST8a8VcfVOTNl353vSrDCLLJXmPk06wTjxrrjcBpXp5EOnYG_NjFZ6OvLFV1jSfS9tsz4qUxcWceqwQGk", 
    //        "y":"ADSmRA43Z1DSNx_RvcLI87cdL07l6jQyyBXMoxVg_l2Th-x3S1WDhjDly79ajL4Kkd0AZMaZmh9ubmf63e3kyMj2" 
    //       } 

    sbPubKey := chilkat.NewStringBuilder()
    sbPubKey.Append("{\"kty\":\"EC\",")
    sbPubKey.Append("\"crv\":\"P-521\",")
    sbPubKey.Append("\"x\":\"AekpBQ8ST8a8VcfVOTNl353vSrDCLLJXmPk06wTjxrrjcBpXp5EOnYG_NjFZ6OvLFV1jSfS9tsz4qUxcWceqwQGk\",")
    sbPubKey.Append("\"y\":\"ADSmRA43Z1DSNx_RvcLI87cdL07l6jQyyBXMoxVg_l2Th-x3S1WDhjDly79ajL4Kkd0AZMaZmh9ubmf63e3kyMj2\"")
    sbPubKey.Append("}")

    pubKey := chilkat.NewPublicKey()
    success = pubKey.LoadFromString(*sbPubKey.GetAsString())
    if success == false {
        fmt.Println(pubKey.LastErrorText())
        sbPubKey.DisposeStringBuilder()
        pubKey.DisposePublicKey()
        return
    }

    jws := chilkat.NewJws()

    //  Set the ECC public key:
    signatureIndex := 0
    jws.SetPublicKey(signatureIndex,pubKey)

    //  Load the JWS.
    sbJws := chilkat.NewStringBuilder()
    sbJws.Append("eyJhbGciOiJFUzUxMiJ9")
    sbJws.Append(".")
    sbJws.Append("UGF5bG9hZA")
    sbJws.Append(".")
    sbJws.Append("AdwMgeerwtHoh-l192l60hp9wAHZFVJbLfD_UxMi70cwnZOYaRI1bKPWROc-mZZq")
    sbJws.Append("wqT2SI-KGDKB34XO0aw_7XdtAG8GaSwFKdCAPZgoXD2YBJZCPEX3xKpRwcdOO8Kp")
    sbJws.Append("EHwJjyqOgzDO7iKvU8vcnwNrmxYbSW9ERBXukOXolLzeO_Jn")

    success = jws.LoadJwsSb(sbJws)
    if success == false {
        fmt.Println(jws.LastErrorText())
        sbPubKey.DisposeStringBuilder()
        pubKey.DisposePublicKey()
        jws.DisposeJws()
        sbJws.DisposeStringBuilder()
        return
    }

    //  Validate the 1st (and only) signature at index 0..
    v := jws.Validate(signatureIndex)
    if v < 0 {
        //  Perhaps Chilkat was not unlocked or the trial expired..
        fmt.Println("Method call failed for some other reason.")
        fmt.Println(jws.LastErrorText())
        sbPubKey.DisposeStringBuilder()
        pubKey.DisposePublicKey()
        jws.DisposeJws()
        sbJws.DisposeStringBuilder()
        return
    }

    if v == 0 {
        fmt.Println("Invalid signature.  The ECC key was incorrect, the JWS was invalid, or both.")
        sbPubKey.DisposeStringBuilder()
        pubKey.DisposePublicKey()
        jws.DisposeJws()
        sbJws.DisposeStringBuilder()
        return
    }

    //  If we get here, the signature was validated..
    fmt.Println("Signature validated.")
    fmt.Println("--")

    //  Recover the original content:
    fmt.Println("Recovered content:")
    fmt.Println(*jws.GetPayload("utf-8"))
    fmt.Println("--")

    //  Examine the protected header:

    joseHeader := chilkat.NewJsonObject()
    success = jws.GetProtectedH(signatureIndex,joseHeader)
    if success == false {
        fmt.Println(jws.LastErrorText())
        sbPubKey.DisposeStringBuilder()
        pubKey.DisposePublicKey()
        jws.DisposeJws()
        sbJws.DisposeStringBuilder()
        joseHeader.DisposeJsonObject()
        return
    }

    joseHeader.SetEmitCompact(false)

    fmt.Println("Protected (JOSE) header:")
    fmt.Println(*joseHeader.Emit())

    //  Output:
    //  (the string "Payload" was the content that was signed.)

    //  	Signature validated.
    //  	--
    //  	Recovered content:
    //  	Payload
    //  	--
    //  	Protected (JOSE) header:
    //  	{
    //  	  "alg": "ES512"
    //  	}

    sbPubKey.DisposeStringBuilder()
    pubKey.DisposePublicKey()
    jws.DisposeJws()
    sbJws.DisposeStringBuilder()
    joseHeader.DisposeJsonObject()