Hello Michel, Thanks for the link. I have the following code. int main() {
RSA *key; unsigned char input_ptext[] = "58FD6F1C310FC9D0194FB8B0E99070A6CBA3473BFE69F953E60E99070A6CBA3473BFE69F953E0E99070A6CBA3473BFE69F953E0E99070A6CBAE"; unsigned char ctext[256]; unsigned char ptext[256]; int n,i; ERR_clear_error(); key = RSA_generate_key(1024,65537,NULL,NULL); printf("the size of input_text is %ld\n", sizeof(input_ptext)); if (!key) return 0; n = RSA_size(key); n = RSA_public_encrypt(sizeof(input_ptext) - 1,input_ptext,ctext,key,RSA_PKCS1_PADDING); if (n < 0) return 0; n = RSA_private_decrypt(n,ctext,ptext,key,RSA_PKCS1_PADDING); if (n < 0) return 0; RSA_free(key); printf("the decrypted text is %s\n",ptext); if (memcmp(input_ptext,ptext,sizeof(input_ptext) - 1)) return 0; printf("Finished\n"); printf("the decrypted text is %s\n",ptext); return 1; } But the problem is, I have to encrypt it at clients side and decrypt it at servers side. In the above program I generated the key at clients side. But How do I transport the public key to the other party for it to generate the private key? If I send the key using TCP/IP channel, that makes the system vulnerable, which is not desirable. So how do I transport the keys between client and the server. Thanks and Regards, Yamini. On Tue, Jun 18, 2013 at 1:43 AM, Michel <msa...@paybox.com> wrote: > Hi Yamini, > > I would suggest looking at the 'EVP Envelope' API : > https://www.openssl.org/docs/**crypto/EVP_SealInit.html<https://www.openssl.org/docs/crypto/EVP_SealInit.html> > > > Le 17/06/2013 19:26, yamini a écrit : > >> Hello, >> >> I am implementing the DES algorithm between my client and server systems >> for >> encryption. The DES key is transmitted in encrypted form between Client >> and >> Server using RSA encryption and decryption. >> My idea of implementing the above task is creating RSA key >> (RSA_generate_key) and using the public key for encryption and private key >> for decryption. I have looked for sample codes to do this in C language >> but >> found nothing. So if anyone has any code snippets for this task please >> post >> them here. It would be very helpful. >> The code for RSA encryption and Decryption between client and >> server(client >> and server are on different machines). >> >> >> Thanks and Regards, >> Yamini. >> > >