(Objective-C) Sign Mexico Pedimento

Add a signature to a Mexico pedimento file.

Chilkat Objective-C Library Downloads MAC OS X (Cocoa) Libs iOS Libs

#import <CkoStringBuilder.h>
#import <NSString.h>
#import <CkoPrivateKey.h>
#import <CkoXml.h>
#import <CkoAsn.h>
#import <CkoRsa.h>
#import <CkoBinData.h>
#import <CkoCert.h>

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

BOOL success;

// 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.
BOOL bCRLF = YES;
CkoStringBuilder *sb = [[CkoStringBuilder alloc] init];
// Use CRLF line endings.
[sb AppendLine: @"500|1|3621|4199800|400||" crlf: bCRLF];
[sb AppendLine: @"601|3621|4199800|400|IN|1||EKU9003173C9|EKU9003173C9FRNN09|1||" crlf: bCRLF];
[sb AppendLine: @"507|4199800|IM|2006-7888">" crlf: bCRLF];
[sb AppendLine: @"507|4199800|MS|2">" crlf: bCRLF];

// Generate the MD5 hash of what we have so far..
NSString *md5_base64 = [sb GetHash: @"md5" encoding: @"base64" charset: @"utf-8"];
NSLog(@"%@%@",@"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|" crlf: bCRLF];
[sb AppendLine: @"801|M3621037.222|1|5|011|" crlf: bCRLF];

// We're going to sign the MD5 hash using the private key.
CkoPrivateKey *privKey = [[CkoPrivateKey alloc] init];
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" password: @"12345678a"];
if (success == NO) {
    NSLog(@"%@",privKey.LastErrorText);
    return;
}

// Generate the ASN.1 to be signed.

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

CkoXml *xml = [[CkoXml alloc] init];
xml.Tag = @"sequence";
[xml UpdateChildContent: @"sequence|oid" value: @"1.2.840.113549.2.5"];
[xml UpdateChildContent: @"sequence|null" value: @""];
[xml UpdateChildContent: @"octets" value: md5_base64];

CkoAsn *asn = [[CkoAsn alloc] init];
[asn LoadAsnXml: [xml GetXml]];
NSLog(@"%@%@",@"ASN.1 = ",[asn GetEncodedDer: @"base64"]);

// Sign with the private key.
CkoRsa *rsa = [[CkoRsa alloc] init];
success = [rsa ImportPrivateKeyObj: privKey];
if (success == NO) {
    NSLog(@"%@",rsa.LastErrorText);
    return;
}

// Create the opaque signature.
CkoBinData *bdSig = [[CkoBinData alloc] init];
[bdSig AppendEncoded: [asn GetEncodedDer: @"base64"] encoding: @"base64"];
success = [rsa OpenSslSignBd: bdSig];
if (success == NO) {
    NSLog(@"%@",rsa.LastErrorText);
    return;
}

// 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|

CkoCert *cert = [[CkoCert alloc] init];
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 == NO) {
    NSLog(@"%@",cert.LastErrorText);
    return;
}

NSString *serialHex = cert.SerialNumber;
// The serial in hex form looks like this:   3330303031303030303030353030303033343136
// Decode to us-ascii.
CkoStringBuilder *sbSerial = [[CkoStringBuilder alloc] init];
[sbSerial DecodeAndAppend: serialHex encoding: @"hex" charset: @"us-ascii"];
NSLog(@"%@%@",@"serial number in us-ascii: ",[sbSerial GetAsString]);

int numReplaced = [[sb Replace: @"CERT_SERIAL" replacement: [sbSerial GetAsString]] intValue];
numReplaced = [[sb Replace: @"BASE64_SIGNATURE" replacement: [bdSig GetEncoded: @"base64"]] intValue];

NSLog(@"%@",@"------------------------------------");
NSLog(@"%@",@"Result:");
NSLog(@"%@",[sb GetAsString]);