I am working in a project to replace my old third party crypto library with openSSL crypto library. I have requirement to maintain the compatibility across the library. i.e. any IP encrypted with older crypto library should be decrypted by openSSL library. I am facing issue in RC5 algorithm even if I am using all the parameters (word size, rounds and key length) same. The older library currently in use is RSA library. They are out of business now and I have to replace it with openSSL.
OpenSSL library being used is: openssl-1.1.0-stable-SNAP-20180501
Please let me know if I am missing something (any setting/ unknown parameter etc) or if there is an issue with RC5. Any pointer in this direction is really appreciated.