OpenSSL always fails verifying signature generated from Bouncy Castle in Java

Question

I'am trying to generate signatures from files, in order to verify them by clients using OpenSSL, so to implement the corresponding openSSL command in Java using Bouncy Castle :

openssl.exe dgst -sha256 -sign privateKey.pem -out \data.txt.sig \data.txt

using bouncy castle 1.57 and java, we get bytes array signature from file, which i could verify it in the code. Private, public and certificate are generated from openSSL.

so to generate certificates :

read the private key from the pem private key file:

PEMParser pemParser = new PEMParser(new FileReader(PRIVATE_FILE_PATH));
                    PKCS8EncryptedPrivateKeyInfo encryptedPrivateKeyInfo = (PKCS8EncryptedPrivateKeyInfo) pemParser.readObject();
JceOpenSSLPKCS8DecryptorProviderBuilder jce = new JceOpenSSLPKCS8DecryptorProviderBuilder();
jce.setProvider("BC");
InputDecryptorProvider decProv = jce.build(password.toCharArray());
PrivateKeyInfo info = encryptedPrivateKeyInfo.decryptPrivateKeyInfo(decProv);
JcaPEMKeyConverter pemKeyConverter = new JcaPEMKeyConverter();
PrivateKey pk = pemKeyConverter.getPrivateKey(info);

and generate the RSA SHA 256 signature and write the result in the signature file:

byte[] data = Files.readAllBytes(Paths.get(txtFileToSignPath));
Signature sig = Signature.getInstance("SHA256withRSA");
sig.initSign(pk);
sig.update(data);
byte[] signature = sig.sign();
FileOutputStream dfis = new FileOutputStream(SignaturefilePath);
dfis.write(bytesToWrite);
dfis.close();

programmatically i could verify signatures generated from the code above as well as from open SSL:

Signature verifySignature = Signature.getInstance("SHA256withRSA"); 
byte[] signatureBytes =  
Files.readAllBytes(Paths.get(SignaturefilePath);
verifySignature.initVerify(getPublicKeyFromCertFile(CERT_PEM));
verifySignature.update(data);
verifySignature.verify(signatureBytes);

on the other hand openSSL is getting always "verification failure" by verifiying signatures generated from code.

is OpenSSL able to verify array of bytes signatures directly, or am I missing anything ?

Answer 1

code above works fine, was verifying the signature against another file. Question maitained for learning purpose.