RSA encryption to sign license files

Hello Coders, I have different applications which uses a license file to be registered. In the license file goes information about Name + Address, etc. So, we want to encrypt that information with RSA (and maybe hash it first with SHA1) and create the license file. When the application is running, it will check for the license file and will decrypt it to get the user information in the license. We want to avoid that someone else creates a fake license file, so we need to sign the license file also. We require the following functions to be implemented: 1) EncryptAndSign(char* LicenseInfo, ..., BufferOut) Where "License" contains a pointer to the license information. Other parameters like "private key" or "public key" and BufferOut The function will encrypt and sigh the license information and generate the output in "BufferOut" 2) DecryptAndVerify(LicenseInfoEncrypted, ...,BufferOut) That function will verify that the license is not tampered and will decrypt the encrypted information. Requeriments ------------- 1) strong RSA encryption (possibility to choose the number of bits 1024, 2048...) 2) Generation of different multiple public and private keys 3) The code must be developed in C (using Visual Studio 2003/2005). If you are using code from libraries like "LibTomCrypt", do not include the whole library but just the necessary functions 4) Simple tests examples to see that the solution works If you have any question, just drop me a line Thank you! ## Deliverables 1) Complete and fully-functional working program(s) in executable form as well as complete source code of all work done. 2) Deliverables must be in ready-to-run condition, as follows (depending on the nature of the deliverables): a) For web sites or other server-side deliverables intended to only ever exist in one place in the Buyer's environment--Deliverables must be installed by the Seller in ready-to-run condition in the Buyer's environment. b) For all others including desktop software or software the buyer intends to distribute: A software installation package that will install the software in ready-to-run condition on the platform(s) specified in this bid request. 3) All deliverables will be considered "work made for hire" under U.S. Copyright law. Buyer will receive exclusive and complete copyrights to all work purchased. (No GPL, GNU, 3rd party components, etc. unless all copyright ramifications are explained AND AGREED TO by the buyer on the site per the coder's Seller Legal Agreement). ## Platform Windows