(PowerBuilder) Create a JWS Using ECDSA P-521 SHA-512

Creates and verifies a JSON Web Signature (JWS) that uses ECDSA P-521 SHA-512

Note: This example requires Chilkat v9.5.0.66 or greater.

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integer li_rc
oleobject loo_SbJwk
oleobject loo_EccKey
integer li_Success
oleobject loo_JwsProtHdr
oleobject loo_Jws
integer li_SignatureIndex
integer li_BIncludeBom
string ls_PayloadStr
string ls_JwsCompact
oleobject loo_Jws2
oleobject loo_EccPubKey
integer v
oleobject loo_JoseHeader

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

// Note: This example requires Chilkat v9.5.0.66 or greater.

// Use the following ECC key loaded from JWK format.
loo_SbJwk = create oleobject
// Use "Chilkat_9_5_0.StringBuilder" for versions of Chilkat < 10.0.0
li_rc = loo_SbJwk.ConnectToNewObject("Chilkat.StringBuilder")
if li_rc < 0 then
    destroy loo_SbJwk
    MessageBox("Error","Connecting to COM object failed")
    return
end if
loo_SbJwk.Append("{~"kty~":~"EC~",")
loo_SbJwk.Append("~"crv~":~"P-521~",")
loo_SbJwk.Append("~"x~":~"AekpBQ8ST8a8VcfVOTNl353vSrDCLLJXmPk06wTjxrrjcBpXp5EOnYG_NjFZ6OvLFV1jSfS9tsz4qUxcWceqwQGk~",")
loo_SbJwk.Append("~"y~":~"ADSmRA43Z1DSNx_RvcLI87cdL07l6jQyyBXMoxVg_l2Th-x3S1WDhjDly79ajL4Kkd0AZMaZmh9ubmf63e3kyMj2~",")
loo_SbJwk.Append("~"d~":~"AY5pb7A0UFiB3RELSD64fTLOSV_jazdF7fLYyuTw8lOfRhWg6Y6rUrPAxerEzgdRhajnu0ferB0d53vM9mE15j2C~"")
loo_SbJwk.Append("}")

loo_EccKey = create oleobject
// Use "Chilkat_9_5_0.PrivateKey" for versions of Chilkat < 10.0.0
li_rc = loo_EccKey.ConnectToNewObject("Chilkat.PrivateKey")

// Note: This example loads the ECDSA key from JWK format.  Any format can be loaded
// into the private key object. (See the online reference documentation..)
li_Success = loo_EccKey.LoadJwk(loo_SbJwk.GetAsString())
if li_Success <> 1 then
    Write-Debug loo_EccKey.LastErrorText
    destroy loo_SbJwk
    destroy loo_EccKey
    return
end if

// Create the JWS Protected Header
loo_JwsProtHdr = create oleobject
// Use "Chilkat_9_5_0.JsonObject" for versions of Chilkat < 10.0.0
li_rc = loo_JwsProtHdr.ConnectToNewObject("Chilkat.JsonObject")

loo_JwsProtHdr.AppendString("alg","ES512")

loo_Jws = create oleobject
// Use "Chilkat_9_5_0.Jws" for versions of Chilkat < 10.0.0
li_rc = loo_Jws.ConnectToNewObject("Chilkat.Jws")

// Set the protected header:
li_SignatureIndex = 0
loo_Jws.SetProtectedHeader(li_SignatureIndex,loo_JwsProtHdr)

// Set the ECC key:
loo_Jws.SetPrivateKey(li_SignatureIndex,loo_EccKey)

// Set the payload.
li_BIncludeBom = 0
ls_PayloadStr = "In our village, folks say God crumbles up the old moon into stars."
loo_Jws.SetPayload(ls_PayloadStr,"utf-8",li_BIncludeBom)

// Create the JWS
// By default, the compact serialization is used.
ls_JwsCompact = loo_Jws.CreateJws()
if loo_Jws.LastMethodSuccess <> 1 then
    Write-Debug loo_Jws.LastErrorText
    destroy loo_SbJwk
    destroy loo_EccKey
    destroy loo_JwsProtHdr
    destroy loo_Jws
    return
end if

Write-Debug "JWS: " + ls_JwsCompact

// Note: ECC signatures use random values, so the output will be different each time a signature is produced.
// sample output:
// JWS: eyJhbGciOiJFUzUxMiJ9.SW4gb3VyIHZpbGxhZ2UsIGZvbGtzIHNheSBHb2QgY3J1bWJsZXMgdXAgdGhlIG9sZCBtb29uIGludG8gc3RhcnMu.AFOnOtZ8UTp-ed1PfLfXxwGU7zT_jnmGGxew-d1CP6SfKa5RUhav5mF4szhSof22JaoQ742VIa0eZ0s1rhBnj8y6APr6g6vKzIpYZlJsnjzjUwAjDQOLmcsjxrrRfATh-NEv7G0Z9FrjdJasS44tCG2EnG6aT2TW-sPG0dy5o9jUWCzi

// Now load the JWS, validate, and recover the original text.
loo_Jws2 = create oleobject
// Use "Chilkat_9_5_0.Jws" for versions of Chilkat < 10.0.0
li_rc = loo_Jws2.ConnectToNewObject("Chilkat.Jws")

// Load the JWS.
li_Success = loo_Jws2.LoadJws(ls_JwsCompact)

loo_EccPubKey = loo_EccKey.GetPublicKey()

// Set the ECC public key used for validation.
li_SignatureIndex = 0
loo_Jws2.SetPublicKey(li_SignatureIndex,loo_EccPubKey)
destroy loo_EccPubKey

// Validate the 1st (and only) signature at index 0..
v = loo_Jws2.Validate(li_SignatureIndex)
if v < 0 then
    // Perhaps Chilkat was not unlocked or the trial expired..
    Write-Debug "Method call failed for some other reason."
    Write-Debug loo_Jws2.LastErrorText
    destroy loo_SbJwk
    destroy loo_EccKey
    destroy loo_JwsProtHdr
    destroy loo_Jws
    destroy loo_Jws2
    return
end if

if v = 0 then
    Write-Debug "Invalid signature.  The ECC key was incorrect, the JWS was invalid, or both."
    destroy loo_SbJwk
    destroy loo_EccKey
    destroy loo_JwsProtHdr
    destroy loo_Jws
    destroy loo_Jws2
    return
end if

// If we get here, the signature was validated..
Write-Debug "Signature validated."

// Recover the original content:
Write-Debug loo_Jws2.GetPayload("utf-8")

// Examine the protected header:
loo_JoseHeader = loo_Jws2.GetProtectedHeader(li_SignatureIndex)
if loo_Jws2.LastMethodSuccess <> 1 then
    Write-Debug "No protected header found at the given index."
    destroy loo_SbJwk
    destroy loo_EccKey
    destroy loo_JwsProtHdr
    destroy loo_Jws
    destroy loo_Jws2
    return
end if

loo_JoseHeader.EmitCompact = 0

Write-Debug "Protected (JOSE) header:"
Write-Debug loo_JoseHeader.Emit()
destroy loo_JoseHeader

// Output:
// 	Signature validated.
// 	In our village, folks say God crumbles up the old moon into stars.
// 	Protected (JOSE) header:
// 	{
// 	  "alg": "ES512"
// 	}


destroy loo_SbJwk
destroy loo_EccKey
destroy loo_JwsProtHdr
destroy loo_Jws
destroy loo_Jws2