PKCS7 Digital Signature

Hello

New to Java here coming from .NET
Trying to implement PKCS7 signing using Java similar to a previous .NET implementation.
Problem is am not able to get the same output.
Same keystore converted from P12 to JKS.

.NET Code


Java Code


Please advise on what I might be doing wrong. I picked up this method online and am open to alternatives if someone has an easier method to implement this.

Thanks

Can't you use an established crypto library such as those made by Bouncy Castle? Their CMS library supports PKCS#7: https://www.bouncycastle.org/docs/pkixdocs1.5on/index.html?org/bouncycastle/cms/package-summary.html

so it is not supported out of the box with JDK ? I need to use some external library ?

Too difficult a question for this forum. Let's try the security forum.