Correct way to sign and verify signature using bouncycastle
Solution 1
The
gen.generate(msg, false)
means the signed data is not encapsulated in the signature. This is fine if you want to create a detached signature, but it does mean that when you go to verify the SignedData you have to use the CMSSignedData constructor that takes a copy of the data as well - in this case the code is using the single argument constructor which has to assume the signed data was encapsulated (so for this case will be empty), with the result that the attempt at verification is failing.
Solution 2
There are two kinds of CMSSignedData object generated using CMSSignedDataGenerator They are generated by the following way:
The one below generates a CMSSignedData object carrying a detached CMS signature
gen.generate(cmsdata);
The code below creates a CMSSignedData carrying a detached CMS signature, having the data encapsulated
gen.generate(cmsdata, true);
So verifying them requires 2 approaches
Approach No.1 to verify detached signature with encapsulated data
//sig is the Signature object
CMSSignedData signedData = new CMSSignedData(Base64.decode(sig.getBytes()));
Approach No.2 to verify detached signature without encapsulated data, just the detached signature
//Create a CMSProcessable object, specify any encoding, I have used mine
CMSProcessable signedContent = new CMSProcessableByteArray(content.getBytes("ISO-8859-1"));
//Create a InputStream object
InputStream is = new ByteArrayInputStream(Base64.decode(sig.getBytes()));
//Pass them both to CMSSignedData constructor
CMSSignedData signedData = new CMSSignedData(signedContent, is);
Rest of the code for verification remains the same
Store store = signedData.getCertificates();
SignerInformationStore signers = signedData.getSignerInfos();
Collection c = signers.getSigners();
Iterator it = c.iterator();
while (it.hasNext()) {
SignerInformation signer = (SignerInformation)it.next();
Collection certCollection = store.getMatches(signer.getSID());
Iterator certIt = certCollection.iterator();
X509CertificateHolder certHolder = (X509CertificateHolder)certIt.next();
X509Certificate cert = new JcaX509CertificateConverter().setProvider("BC").getCertificate(certHolder);
if (signer.verify(new JcaSimpleSignerInfoVerifierBuilder().setProvider("BC").build(cert))) {
ret = true;
}
}
Solution 3
If we use signature.sign() as in the OP's answer, we won't be able to retrieve the original message, because its only the signature.
You should just input the original text bytes rather than the signed content. Basically, ignore this part:
//Sign
PrivateKey privKey = (PrivateKey) key;
Signature signature = Signature.getInstance("SHA1WithRSA", "BC");
signature.initSign(privKey);
signature.update(text.getBytes());
and just input as:
CMSTypedData msg = new CMSProcessableByteArray(text.getBytes());
Solution 4
Got it working for detached signature :D
package signature;
import java.security.Provider;
import java.security.Security;
import java.security.cert.X509Certificate;
import java.util.Collection;
import java.util.Iterator;
import org.bouncycastle.cert.X509CertificateHolder;
import org.bouncycastle.cert.jcajce.JcaX509CertificateConverter;
import org.bouncycastle.cms.CMSProcessable;
import org.bouncycastle.cms.CMSProcessableByteArray;
import org.bouncycastle.cms.CMSSignedData;
import org.bouncycastle.cms.SignerInformation;
import org.bouncycastle.cms.SignerInformationStore;
import org.bouncycastle.cms.jcajce.JcaSimpleSignerInfoVerifierBuilder;
import org.bouncycastle.jce.provider.BouncyCastleProvider;
import org.bouncycastle.util.Store;
import org.bouncycastle.util.encoders.Base64;
public class VerifySignature {
static final String DIGEST_SHA1 = "SHA1withRSA";
static final String BC_PROVIDER = "BC";
public static void main(String[] args) throws Exception {
String envelopedData = "MIAGCSqGSIb3DQEHAqCAMIACAQExCzAJBgUrDgMCGgUAMIAGCSqGSIb3DQEHAQAAoIAwggLQMIIC" +
"OQIEQ479uzANBgkqhkiG9w0BAQUFADCBrjEmMCQGCSqGSIb3DQEJARYXcm9zZXR0YW5ldEBtZW5k" +
"ZWxzb24uZGUxCzAJBgNVBAYTAkRFMQ8wDQYDVQQIEwZCZXJsaW4xDzANBgNVBAcTBkJlcmxpbjEi" +
"MCAGA1UEChMZbWVuZGVsc29uLWUtY29tbWVyY2UgR21iSDEiMCAGA1UECxMZbWVuZGVsc29uLWUt" +
"Y29tbWVyY2UgR21iSDENMAsGA1UEAxMEbWVuZDAeFw0wNTEyMDExMzQyMTlaFw0xOTA4MTAxMzQy" +
"MTlaMIGuMSYwJAYJKoZIhvcNAQkBFhdyb3NldHRhbmV0QG1lbmRlbHNvbi5kZTELMAkGA1UEBhMC" +
"REUxDzANBgNVBAgTBkJlcmxpbjEPMA0GA1UEBxMGQmVybGluMSIwIAYDVQQKExltZW5kZWxzb24t" +
"ZS1jb21tZXJjZSBHbWJIMSIwIAYDVQQLExltZW5kZWxzb24tZS1jb21tZXJjZSBHbWJIMQ0wCwYD" +
"VQQDEwRtZW5kMIGfMA0GCSqGSIb3DQEBAQUAA4GNADCBiQKBgQC+X1g6JvbdwJI6mQMNT41GcycH" +
"UbwCFWKJ4qHDaHffz3n4h+uQJJoQvc8yLTCfnl109GB0yL2Y5YQtTohOS9IwyyMWBhh77WJtCN8r" +
"dOfD2DW17877te+NlpugRvg6eOH6np9Vn3RZODVxxTyyJ8pI8VMnn13YeyMMw7VVaEO5hQIDAQAB" +
"MA0GCSqGSIb3DQEBBQUAA4GBALwOIc/rWMAANdEh/GgO/DSkVMwxM5UBr3TkYbLU/5jg0Lwj3Y++" +
"KhumYSrxnYewSLqK+JXA4Os9NJ+b3eZRZnnYQ9eKeUZgdE/QP9XE04y8WL6ZHLB4sDnmsgVaTU+p" +
"0lFyH0Te9NyPBG0J88109CXKdXCTSN5gq0S1CfYn0staAAAxggG9MIIBuQIBATCBtzCBrjEmMCQG" +
"CSqGSIb3DQEJARYXcm9zZXR0YW5ldEBtZW5kZWxzb24uZGUxCzAJBgNVBAYTAkRFMQ8wDQYDVQQI" +
"EwZCZXJsaW4xDzANBgNVBAcTBkJlcmxpbjEiMCAGA1UEChMZbWVuZGVsc29uLWUtY29tbWVyY2Ug" +
"R21iSDEiMCAGA1UECxMZbWVuZGVsc29uLWUtY29tbWVyY2UgR21iSDENMAsGA1UEAxMEbWVuZAIE" +
"Q479uzAJBgUrDgMCGgUAoF0wGAYJKoZIhvcNAQkDMQsGCSqGSIb3DQEHATAcBgkqhkiG9w0BCQUx" +
"DxcNMTMwNTIxMDE1MDUzWjAjBgkqhkiG9w0BCQQxFgQU8mE6gw6iudxLUc9379lWK0lUSWcwDQYJ" +
"KoZIhvcNAQEBBQAEgYB5mVhqJu1iX9nUqfqk7hTYJb1lR/hQiCaxruEuInkuVTglYuyzivZjAR54" +
"zx7Cfm5lkcRyyxQ35ztqoq/V5JzBa+dYkisKcHGptJX3CbmmDIa1s65mEye4eLS4MTBvXCNCUTb9" +
"STYSWvr4VPenN80mbpqSS6JpVxjM0gF3QTAhHwAAAAAAAA==";
String Sig_Bytes ="YduK22AlMLSXV3ajX5r/pX5OQ0xjj58uhGT9I9MvOrz912xNHo+9OiOKeMOD+Ys2/LUW3XaN6T+/"+
"tuRM5bi4RK7yjaqaJCZWtr/O4I968BQGgt0cyNvK8u0Jagbr9MYk6G7nnejbRXYHyAOaunqD05lW"+
"U/+g92i18dl0OMc50m4=";
Provider provider = new BouncyCastleProvider();
Security.addProvider(provider);
CMSSignedData signedData = new CMSSignedData(Base64.decode(envelopedData.getBytes()));
CMSProcessable cmsProcesableContent = new CMSProcessableByteArray(Base64.decode(Sig_Bytes.getBytes()));
signedData = new CMSSignedData(cmsProcesableContent, Base64.decode(envelopedData.getBytes()));
// Verify signature
Store store = signedData.getCertificates();
SignerInformationStore signers = signedData.getSignerInfos();
Collection c = signers.getSigners();
Iterator it = c.iterator();
while (it.hasNext()) {
SignerInformation signer = (SignerInformation) it.next();
Collection certCollection = store.getMatches(signer.getSID());
Iterator certIt = certCollection.iterator();
X509CertificateHolder certHolder = (X509CertificateHolder) certIt.next();
X509Certificate certFromSignedData = new JcaX509CertificateConverter().setProvider(BC_PROVIDER).getCertificate(certHolder);
if (signer.verify(new JcaSimpleSignerInfoVerifierBuilder().setProvider(BC_PROVIDER).build(certFromSignedData))) {
System.out.println("Signature verified");
} else {
System.out.println("Signature verification failed");
}
}
}
}
Solution 5
You can find answer at this link here You need to just add some headers to message or just add one blank line before message then sign the message then it will work fine.
Oscar Jara
Updated on May 10, 2021Comments
-
Oscar Jara almost 3 years
I am using
bcmail-jdk16-1.46.jar
andbcprov-jdk16-1.46.jar
(Bouncycastle libraries) to sign astring
and then verify thesignature
.This is my
code
to sign astring
:package my.package; import java.io.FileInputStream; import java.security.Key; import java.security.KeyStore; import java.security.PrivateKey; import java.security.Security; import java.security.Signature; import java.security.cert.X509Certificate; import java.util.ArrayList; import java.util.List; import org.bouncycastle.cert.jcajce.JcaCertStore; import org.bouncycastle.cms.CMSProcessableByteArray; import org.bouncycastle.cms.CMSSignedData; import org.bouncycastle.cms.CMSSignedDataGenerator; import org.bouncycastle.cms.CMSTypedData; import org.bouncycastle.cms.jcajce.JcaSignerInfoGeneratorBuilder; import org.bouncycastle.jce.provider.BouncyCastleProvider; import org.bouncycastle.operator.ContentSigner; import org.bouncycastle.operator.jcajce.JcaContentSignerBuilder; import org.bouncycastle.operator.jcajce.JcaDigestCalculatorProviderBuilder; import org.bouncycastle.util.Store; import sun.misc.BASE64Encoder; public class SignMessage { static final String KEYSTORE_FILE = "keys/certificates.p12"; static final String KEYSTORE_INSTANCE = "PKCS12"; static final String KEYSTORE_PWD = "test"; static final String KEYSTORE_ALIAS = "Key1"; public static void main(String[] args) throws Exception { String text = "This is a message"; Security.addProvider(new BouncyCastleProvider()); KeyStore ks = KeyStore.getInstance(KEYSTORE_INSTANCE); ks.load(new FileInputStream(KEYSTORE_FILE), KEYSTORE_PWD.toCharArray()); Key key = ks.getKey(KEYSTORE_ALIAS, KEYSTORE_PWD.toCharArray()); //Sign PrivateKey privKey = (PrivateKey) key; Signature signature = Signature.getInstance("SHA1WithRSA", "BC"); signature.initSign(privKey); signature.update(text.getBytes()); //Build CMS X509Certificate cert = (X509Certificate) ks.getCertificate(KEYSTORE_ALIAS); List certList = new ArrayList(); CMSTypedData msg = new CMSProcessableByteArray(signature.sign()); certList.add(cert); Store certs = new JcaCertStore(certList); CMSSignedDataGenerator gen = new CMSSignedDataGenerator(); ContentSigner sha1Signer = new JcaContentSignerBuilder("SHA1withRSA").setProvider("BC").build(privKey); gen.addSignerInfoGenerator(new JcaSignerInfoGeneratorBuilder(new JcaDigestCalculatorProviderBuilder().setProvider("BC").build()).build(sha1Signer, cert)); gen.addCertificates(certs); CMSSignedData sigData = gen.generate(msg, false); BASE64Encoder encoder = new BASE64Encoder(); String signedContent = encoder.encode((byte[]) sigData.getSignedContent().getContent()); System.out.println("Signed content: " + signedContent + "\n"); String envelopedData = encoder.encode(sigData.getEncoded()); System.out.println("Enveloped data: " + envelopedData); } }
Now, the
EnvelopedData
output will be used in the process toverify
thesignature
:package my.package; import java.security.Security; import java.security.cert.X509Certificate; import java.util.Collection; import java.util.Iterator; import org.bouncycastle.cert.X509CertificateHolder; import org.bouncycastle.cert.jcajce.JcaX509CertificateConverter; import org.bouncycastle.cms.CMSSignedData; import org.bouncycastle.cms.SignerInformation; import org.bouncycastle.cms.SignerInformationStore; import org.bouncycastle.cms.jcajce.JcaSimpleSignerInfoVerifierBuilder; import org.bouncycastle.jce.provider.BouncyCastleProvider; import org.bouncycastle.util.Store; import org.bouncycastle.util.encoders.Base64; public class VerifySignature { public static void main(String[] args) throws Exception { String envelopedData = "MIAGCSqGSIb3DQEHAqCAMIACAQExCzAJBgUrDgMCGgUAMIAGCSqGSIb3DQEHAQAAoIAwggLQMIIC" + "OQIEQ479uzANBgkqhkiG9w0BAQUFADCBrjEmMCQGCSqGSIb3DQEJARYXcm9zZXR0YW5ldEBtZW5k" + "ZWxzb24uZGUxCzAJBgNVBAYTAkRFMQ8wDQYDVQQIEwZCZXJsaW4xDzANBgNVBAcTBkJlcmxpbjEi" + "MCAGA1UEChMZbWVuZGVsc29uLWUtY29tbWVyY2UgR21iSDEiMCAGA1UECxMZbWVuZGVsc29uLWUt" + "Y29tbWVyY2UgR21iSDENMAsGA1UEAxMEbWVuZDAeFw0wNTEyMDExMzQyMTlaFw0xOTA4MTAxMzQy" + "MTlaMIGuMSYwJAYJKoZIhvcNAQkBFhdyb3NldHRhbmV0QG1lbmRlbHNvbi5kZTELMAkGA1UEBhMC" + "REUxDzANBgNVBAgTBkJlcmxpbjEPMA0GA1UEBxMGQmVybGluMSIwIAYDVQQKExltZW5kZWxzb24t" + "ZS1jb21tZXJjZSBHbWJIMSIwIAYDVQQLExltZW5kZWxzb24tZS1jb21tZXJjZSBHbWJIMQ0wCwYD" + "VQQDEwRtZW5kMIGfMA0GCSqGSIb3DQEBAQUAA4GNADCBiQKBgQC+X1g6JvbdwJI6mQMNT41GcycH" + "UbwCFWKJ4qHDaHffz3n4h+uQJJoQvc8yLTCfnl109GB0yL2Y5YQtTohOS9IwyyMWBhh77WJtCN8r" + "dOfD2DW17877te+NlpugRvg6eOH6np9Vn3RZODVxxTyyJ8pI8VMnn13YeyMMw7VVaEO5hQIDAQAB" + "MA0GCSqGSIb3DQEBBQUAA4GBALwOIc/rWMAANdEh/GgO/DSkVMwxM5UBr3TkYbLU/5jg0Lwj3Y++" + "KhumYSrxnYewSLqK+JXA4Os9NJ+b3eZRZnnYQ9eKeUZgdE/QP9XE04y8WL6ZHLB4sDnmsgVaTU+p" + "0lFyH0Te9NyPBG0J88109CXKdXCTSN5gq0S1CfYn0staAAAxggG9MIIBuQIBATCBtzCBrjEmMCQG" + "CSqGSIb3DQEJARYXcm9zZXR0YW5ldEBtZW5kZWxzb24uZGUxCzAJBgNVBAYTAkRFMQ8wDQYDVQQI" + "EwZCZXJsaW4xDzANBgNVBAcTBkJlcmxpbjEiMCAGA1UEChMZbWVuZGVsc29uLWUtY29tbWVyY2Ug" + "R21iSDEiMCAGA1UECxMZbWVuZGVsc29uLWUtY29tbWVyY2UgR21iSDENMAsGA1UEAxMEbWVuZAIE" + "Q479uzAJBgUrDgMCGgUAoF0wGAYJKoZIhvcNAQkDMQsGCSqGSIb3DQEHATAcBgkqhkiG9w0BCQUx" + "DxcNMTMwNTIxMDE1MDUzWjAjBgkqhkiG9w0BCQQxFgQU8mE6gw6iudxLUc9379lWK0lUSWcwDQYJ" + "KoZIhvcNAQEBBQAEgYB5mVhqJu1iX9nUqfqk7hTYJb1lR/hQiCaxruEuInkuVTglYuyzivZjAR54" + "zx7Cfm5lkcRyyxQ35ztqoq/V5JzBa+dYkisKcHGptJX3CbmmDIa1s65mEye4eLS4MTBvXCNCUTb9" + "STYSWvr4VPenN80mbpqSS6JpVxjM0gF3QTAhHwAAAAAAAA=="; Security.addProvider(new BouncyCastleProvider()); CMSSignedData cms = new CMSSignedData(Base64.decode(envelopedData.getBytes())); Store store = cms.getCertificates(); SignerInformationStore signers = cms.getSignerInfos(); Collection c = signers.getSigners(); Iterator it = c.iterator(); while (it.hasNext()) { SignerInformation signer = (SignerInformation) it.next(); Collection certCollection = store.getMatches(signer.getSID()); Iterator certIt = certCollection.iterator(); X509CertificateHolder certHolder = (X509CertificateHolder) certIt.next(); X509Certificate cert = new JcaX509CertificateConverter().setProvider("BC").getCertificate(certHolder); if (signer.verify(new JcaSimpleSignerInfoVerifierBuilder().setProvider("BC").build(cert))) { System.out.println("verified"); } } } }
Everything works fine until
signer.verify(..)
due to the followingException
:Exception in thread "main" org.bouncycastle.cms.CMSSignerDigestMismatchException: message-digest attribute value does not match calculated value at org.bouncycastle.cms.SignerInformation.doVerify(Unknown Source) at org.bouncycastle.cms.SignerInformation.verify(Unknown Source) at my.package.VerifySignature.main(VerifySignature.java:64)
Can someone please give me a hint of what could be happening?
PS. If someone wants to test above
code
you will need the testcertificate
file that I am using to replicate this, justdownload
it from here:https://www.dropbox.com/s/zs4jo1a86v8qamw/certificates.p12?dl=0