B4X Requires Chilkat v11.0.0+

Sign Mexico Pedimento

See more Misc Examples

Add a signature to a Mexico pedimento file. B4X

Dim success As Boolean = False

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

'  This is the contents before signing:

'  500|1|3621|4199800|400||
'  601|3621|4199800|400|IN|1||EKU9003173C9|EKU9003173C9FRNN09|1||
'  507|4199800|IM|2006-7888">
'  507|4199800|MS|2">
'  800|4199800|1">
'  801|M3621037.222|1|5|011|

'  This is the contents after signing

'  500|1|3621|4199800|400||
'  601|3621|4199800|400|IN|1||EKU9003173C9|EKU9003173C9FRNN09|1||
'  507|4199800|IM|2006-7888">
'  507|4199800|MS|2">
'  800|4199800|1|fhP2Ker54D2+3+UZch23F0E72 .... 9qNSPIuAqpj524qLZbbA==|30001000000500003416|
'  801|M3621037.222|1|5|011|

'  First create the text to be signed.
Dim bCRLF As Boolean = True
Dim sb As ChilkatStringBuilder
sb.Initialize
'  Use CRLF line endings.
sb.AppendLine("500|1|3621|4199800|400||", bCRLF)
sb.AppendLine("601|3621|4199800|400|IN|1||EKU9003173C9|EKU9003173C9FRNN09|1||", bCRLF)
sb.AppendLine("507|4199800|IM|2006-7888">", bCRLF)
sb.AppendLine("507|4199800|MS|2">", bCRLF)

'  Generate the MD5 hash of what we have so far..
Dim md5_base64 As String = sb.GetHash("md5", "base64", "utf-8")
Log("MD5 hash = " & md5_base64)

'  Complete the original file.
'  After signing, we'll update the BASE64_SIGNATURE and CERT_SERIAL
sb.AppendLine("800|4199800|1|BASE64_SIGNATURE|CERT_SERIAL|", bCRLF)
sb.AppendLine("801|M3621037.222|1|5|011|", bCRLF)

'  We're going to sign the MD5 hash using the private key.
Dim privKey As ChilkatPrivateKey
privKey.Initialize("privKey")
success = privKey.LoadAnyFormatFile("qa_data/certs/mexico_test/Certificados_de_Prueba/Certificados_Pruebas/Personas Morales/EKU9003173C9_20230517223532/CSD_EKU9003173C9_20230517223903/CSD_Sucursal_1_EKU9003173C9_20230517_223850.key", "12345678a")
If success = False Then
    Log(privKey.LastErrorText)
    Return
End If


'  Generate the ASN.1 to be signed.

'  <sequence>
'      <sequence>
'          <oid>1.2.840.113549.2.5</oid>
'          <null/>
'      </sequence>
'      <octets>SwxHfaJhG+N3pPqay6UzVA==</octets>
'  </sequence>

Dim xml As ChilkatXml
xml.Initialize
xml.Tag = "sequence"
xml.UpdateChildContent("sequence|oid", "1.2.840.113549.2.5")
xml.UpdateChildContent("sequence|null", "")
xml.UpdateChildContent("octets", md5_base64)

Dim asn As ChilkatAsn
asn.Initialize
asn.LoadAsnXml(xml.GetXml)
Log("ASN.1 = " & asn.GetEncodedDer("base64"))

'  Sign with the private key.
Dim rsa As ChilkatRsa
rsa.Initialize
success = rsa.UsePrivateKey(privKey)
If success = False Then
    Log(rsa.LastErrorText)
    Return
End If


'  Create the opaque signature.
Dim bdSig As ChilkatBinData
bdSig.Initialize
bdSig.AppendEncoded(asn.GetEncodedDer("base64"), "base64")
success = rsa.SignRawBd(bdSig)
If success = False Then
    Log(rsa.LastErrorText)
    Return
End If


'  bd now contains the opaque signature, which embeds the ASN.1, which contains the MD5 hash.
'  We're going to add this line:
'  800|4199800|1|BASE64_SIGNATURE|CERT_SERIAL_NUM|

Dim cert As ChilkatCert
cert.Initialize("cert")
success = cert.LoadFromFile("qa_data/certs/mexico_test/Certificados_de_Prueba/Certificados_Pruebas/Personas Morales/EKU9003173C9_20230517223532/CSD_EKU9003173C9_20230517223903/CSD_Sucursal_1_EKU9003173C9_20230517_223850.cer")
If success = False Then
    Log(cert.LastErrorText)
    Return
End If


Dim serialHex As String = cert.SerialNumber
'  The serial in hex form looks like this:   3330303031303030303030353030303033343136
'  Decode to us-ascii.
Dim sbSerial As ChilkatStringBuilder
sbSerial.Initialize
sbSerial.DecodeAndAppend(serialHex, "hex", "us-ascii")
Log("serial number in us-ascii: " & sbSerial.GetAsString)

Dim numReplaced As Int = sb.Replace("CERT_SERIAL", sbSerial.GetAsString)
numReplaced = sb.Replace("BASE64_SIGNATURE", bdSig.GetEncoded("base64"))

Log("------------------------------------")
Log("Result:")
Log(sb.GetAsString)