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Objective-C

XML Signature Multiple External References

See more XML Digital Signatures Examples

Demonstrates how to add multiple external references to an XML digital signature.

Chilkat Objective-C Downloads

Objective-C
#import <CkoXmlDSigGen.h>
#import <CkoXml.h>
#import <CkoHttp.h>
#import <CkoBinData.h>
#import <NSString.h>
#import <CkoCert.h>
#import <CkoStringBuilder.h>
#import <CkoXmlDSig.h>

BOOL success = NO;

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

// This example creates the following signed XML with multiple external references:

// <?xml version="1.0" encoding="UTF-8"?>
// <ds:Signature xmlns:ds="http://www.w3.org/2000/09/xmldsig#" Id="xmldsig-2dde88a8-def0-43e4-8570-b031015a46b4">
//     <ds:SignedInfo>
//         <ds:CanonicalizationMethod Algorithm="http://www.w3.org/TR/2001/REC-xml-c14n-20010315"/>
//         <ds:SignatureMethod Algorithm="http://www.w3.org/2001/04/xmldsig-more#rsa-sha256"/>
//         <ds:Reference Id="xmldsig-2dde88a8-def0-43e4-8570-b031015a46b4-ref0" URI="https://isus.ezdrowie.gov.pl/fhir/Patient/123/_history/456">
//             <ds:DigestMethod Algorithm="http://www.w3.org/2001/04/xmlenc#sha256"/>
//             <ds:DigestValue>...</ds:DigestValue>
//         </ds:Reference>
//         <ds:Reference Id="xmldsig-2dde88a8-def0-43e4-8570-b031015a46b4-ref1" URI="https://isus.ezdrowie.gov.pl/fhir/Encounter/124/_history/22">
//             <ds:DigestMethod Algorithm="http://www.w3.org/2001/04/xmlenc#sha256"/>
//             <ds:DigestValue>...</ds:DigestValue>
//         </ds:Reference>
//         <ds:Reference Id="xmldsig-2dde88a8-def0-43e4-8570-b031015a46b4-ref2" URI="https://isus.ezdrowie.gov.pl/fhir/Condition/125/_history/1">
//             <ds:DigestMethod Algorithm="http://www.w3.org/2001/04/xmlenc#sha256"/>
//             <ds:DigestValue>...</ds:DigestValue>
//         </ds:Reference>
//         <ds:Reference Id="xmldsig-2dde88a8-def0-43e4-8570-b031015a46b4-ref3" URI="https://isus.ezdrowie.gov.pl/fhir/Procedure/126/_history/1">
//             <ds:DigestMethod Algorithm="http://www.w3.org/2001/04/xmlenc#sha256"/>
//             <ds:DigestValue>...</ds:DigestValue>
//         </ds:Reference>
//         <ds:Reference Type="http://uri.etsi.org/01903#SignedProperties" URI="#xmldsig-2dde88a8-def0-43e4-8570-b031015a46b4-signedprops">
//             <ds:Transforms>
//                 <ds:Transform Algorithm="http://www.w3.org/TR/2001/REC-xml-c14n-20010315"/>
//             </ds:Transforms>
//             <ds:DigestMethod Algorithm="http://www.w3.org/2001/04/xmlenc#sha256"/>
//             <ds:DigestValue>...</ds:DigestValue>
//         </ds:Reference>
//     </ds:SignedInfo>
//     <ds:SignatureValue Id="xmldsig-2dde88a8-def0-43e4-8570-b031015a46b4-sigvalue">...</ds:SignatureValue>
//     <ds:KeyInfo>
//         <ds:X509Data>
//             <ds:X509Certificate>...</ds:X509Certificate>
//             <ds:X509SubjectName>...</ds:X509SubjectName>
//             <ds:X509IssuerSerial>
//                 <ds:X509IssuerName>...</ds:X509IssuerName>
//                 <ds:X509SerialNumber>...</ds:X509SerialNumber>
//             </ds:X509IssuerSerial>
//         </ds:X509Data>
//     </ds:KeyInfo>
//     <ds:Object>
//         <xades:QualifyingProperties xmlns:xades="http://uri.etsi.org/01903/v1.3.2#" xmlns:xades141="http://uri.etsi.org/01903/v1.4.1#" Target="#xmldsig-2dde88a8-def0-43e4-8570-b031015a46b4">
//             <xades:SignedProperties Id="xmldsig-2dde88a8-def0-43e4-8570-b031015a46b4-signedprops">
//                 <xades:SignedSignatureProperties>
//                     <xades:SigningTime>2021-06-02T07:10:13.306+02:00</xades:SigningTime>
//                     <xades:SigningCertificate>
//                         <xades:Cert>
//                             <xades:CertDigest>
//                                 <ds:DigestMethod Algorithm="http://www.w3.org/2001/04/xmlenc#sha256"/>
//                                 <ds:DigestValue>...</ds:DigestValue>
//                             </xades:CertDigest>
//                             <xades:IssuerSerial>
//                                 <ds:X509IssuerName>...</ds:X509IssuerName>
//                                 <ds:X509SerialNumber>...</ds:X509SerialNumber>
//                             </xades:IssuerSerial>
//                         </xades:Cert>
//                         <xades:Cert>
//                             <xades:CertDigest>
//                                 <ds:DigestMethod Algorithm="http://www.w3.org/2001/04/xmlenc#sha256"/>
//                                 <ds:DigestValue>...</ds:DigestValue>
//                             </xades:CertDigest>
//                             <xades:IssuerSerial>
//                                 <ds:X509IssuerName>...</ds:X509IssuerName>
//                                 <ds:X509SerialNumber>...</ds:X509SerialNumber>
//                             </xades:IssuerSerial>
//                         </xades:Cert>
//                         <xades:Cert>
//                             <xades:CertDigest>
//                                 <ds:DigestMethod Algorithm="http://www.w3.org/2001/04/xmlenc#sha256"/>
//                                 <ds:DigestValue>...</ds:DigestValue>
//                             </xades:CertDigest>
//                             <xades:IssuerSerial>
//                                 <ds:X509IssuerName>...</ds:X509IssuerName>
//                                 <ds:X509SerialNumber>...</ds:X509SerialNumber>
//                             </xades:IssuerSerial>
//                         </xades:Cert>
//                     </xades:SigningCertificate>
//                 </xades:SignedSignatureProperties>
//             </xades:SignedProperties>
//         </xades:QualifyingProperties>
//     </ds:Object>
// </ds:Signature>
// 

success = YES;
CkoXmlDSigGen *gen = [[CkoXmlDSigGen alloc] init];

gen.SigLocation = @"";
gen.SigLocationMod = [NSNumber numberWithInt:0];
// Note: ID's simply need to be unique values in the signed XML document.  They don't necessarily need to be GUID/UUID formatted.
gen.SigId = @"xmldsig-2dde88a8-def0-43e4-8570-b031015a46b4";
gen.SigNamespacePrefix = @"ds";
gen.SigNamespaceUri = @"http://www.w3.org/2000/09/xmldsig#";
gen.SigValueId = @"xmldsig-2dde88a8-def0-43e4-8570-b031015a46b4-sigvalue";
gen.SignedInfoCanonAlg = @"C14N";
gen.SignedInfoDigestMethod = @"sha256";

// Create an Object to be added to the Signature.
CkoXml *object1 = [[CkoXml alloc] init];
object1.Tag = @"xades:QualifyingProperties";
[object1 AddAttribute: @"xmlns:xades" value: @"http://uri.etsi.org/01903/v1.3.2#"];
[object1 AddAttribute: @"xmlns:xades141" value: @"http://uri.etsi.org/01903/v1.4.1#"];
[object1 AddAttribute: @"Target" value: @"#xmldsig-2dde88a8-def0-43e4-8570-b031015a46b4"];
[object1 UpdateAttrAt: @"xades:SignedProperties" autoCreate: YES attrName: @"Id" attrValue: @"xmldsig-2dde88a8-def0-43e4-8570-b031015a46b4-signedprops"];
[object1 UpdateChildContent: @"xades:SignedProperties|xades:SignedSignatureProperties|xades:SigningTime" value: @"TO BE GENERATED BY CHILKAT"];
// This assumes there are 3 certs in the certificate chain:  The signing certificate, an intermediate root, and the root CA.
// Remove the lines with "Cert[2]" if there is no intermediate root...
[object1 UpdateAttrAt: @"xades:SignedProperties|xades:SignedSignatureProperties|xades:SigningCertificateV2|xades:Cert|xades:CertDigest|ds:DigestMethod" autoCreate: YES attrName: @"Algorithm" attrValue: @"http://www.w3.org/2001/04/xmlenc#sha256"];
[object1 UpdateChildContent: @"xades:SignedProperties|xades:SignedSignatureProperties|xades:SigningCertificateV2|xades:Cert|xades:CertDigest|ds:DigestValue" value: @"TO BE GENERATED BY CHILKAT"];
[object1 UpdateChildContent: @"xades:SignedProperties|xades:SignedSignatureProperties|xades:SigningCertificateV2|xades:Cert|xades:IssuerSerialV2" value: @"TO BE GENERATED BY CHILKAT"];

[gen AddObject: @"" content: [object1 GetXml] mimeType: @"" encoding: @""];

CkoHttp *http = [[CkoHttp alloc] init];
CkoBinData *bd = [[CkoBinData alloc] init];

NSString *url = @"https://isus.ezdrowie.gov.pl/fhir/Patient/123/_history/456";
success = [http QuickGetBd: url binData: bd];
if (success != YES) {
    NSLog(@"%@",http.LastErrorText);
    return;
}

// -------- Reference 1 --------
[gen AddExternalBinaryRef: url content: bd digestMethod: @"sha256" refType: @""];
[gen SetRefIdAttr: url value: @"xmldsig-2dde88a8-def0-43e4-8570-b031015a46b4-ref0"];

// -------- Reference 2 --------
[bd Clear];
url = @"https://isus.ezdrowie.gov.pl/fhir/Encounter/789/_history/1";
success = [http QuickGetBd: url binData: bd];
if (success != YES) {
    NSLog(@"%@",http.LastErrorText);
    return;
}

[gen AddExternalBinaryRef: url content: bd digestMethod: @"sha256" refType: @""];
[gen SetRefIdAttr: url value: @"xmldsig-2dde88a8-def0-43e4-8570-b031015a46b4-ref1"];

// -------- Reference 3 --------
[bd Clear];
url = @"https://isus.ezdrowie.gov.pl/fhir/Condition/123456/_history/1";
success = [http QuickGetBd: url binData: bd];
if (success != YES) {
    NSLog(@"%@",http.LastErrorText);
    return;
}

[gen AddExternalBinaryRef: url content: bd digestMethod: @"sha256" refType: @""];
[gen SetRefIdAttr: url value: @"xmldsig-2dde88a8-def0-43e4-8570-b031015a46b4-ref2"];

// -------- Reference 4 --------
[bd Clear];
url = @"https://isus.ezdrowie.gov.pl/fhir/Procedure/123456/_history/1";
success = [http QuickGetBd: url binData: bd];
if (success != YES) {
    NSLog(@"%@",http.LastErrorText);
    return;
}

[gen AddExternalBinaryRef: url content: bd digestMethod: @"sha256" refType: @""];
[gen SetRefIdAttr: url value: @"xmldsig-2dde88a8-def0-43e4-8570-b031015a46b4-ref3"];

// -------- Reference 5 --------
[gen AddObjectRef: @"xmldsig-2dde88a8-def0-43e4-8570-b031015a46b4-signedprops" digestMethod: @"sha256" canonMethod: @"C14N" prefixList: @"" refType: @"http://uri.etsi.org/01903#SignedProperties"];

// Provide a certificate + private key. (PFX password is test123)
CkoCert *cert = [[CkoCert alloc] init];
success = [cert LoadPfxFile: @"qa_data/pfx/cert_test123.pfx" password: @"test123"];
if (success != YES) {
    NSLog(@"%@",cert.LastErrorText);
    return;
}

[gen SetX509Cert: cert usePrivateKey: YES];

gen.KeyInfoType = @"X509Data";
gen.X509Type = @"IssuerSerial,SubjectName,Certificate";

// This will be an enveloping signature where the Signature element
// is the XML document root, the signed data is contained within Object
// tag(s) within the Signature.
// Therefore, pass an empty sbXml to CreateXmlDsigSb.
CkoStringBuilder *sbXml = [[CkoStringBuilder alloc] init];

gen.Behaviors = @"IndentedSignature";

// Sign the XML...
success = [gen CreateXmlDSigSb: sbXml];
if (success != YES) {
    NSLog(@"%@",gen.LastErrorText);
    return;
}

// -----------------------------------------------

// Save the signed XML to a file.
success = [sbXml WriteFile: @"qa_output/signedXml.xml" charset: @"utf-8" emitBom: NO];

NSLog(@"%@",[sbXml GetAsString]);

// ----------------------------------------
// Verify the signature we just produced...
CkoXmlDSig *verifier = [[CkoXmlDSig alloc] init];
success = [verifier LoadSignatureSb: sbXml];
if (success != YES) {
    NSLog(@"%@",verifier.LastErrorText);
    return;
}

BOOL verified = [verifier VerifySignature: YES];
if (verified != YES) {
    NSLog(@"%@",verifier.LastErrorText);
    return;
}

NSLog(@"%@",@"This signature was successfully verified.");