You can also use the RAND_status() function that implicitly calls RAND_poll(). RAND_poll() actually uses memory state, processes, handles, screen state... to initialize the PRNG. If it is not sufficiant (it usually is), you can read some entropy from a file using RAND_read() function.
Marc. > -----Message d'origine----- > De : lbfi [mailto:[EMAIL PROTECTED] > Envoyé : mardi 10 août 2004 12:59 > À : openssl-users > Objet : Re:Random number seed in RSA > > > You can use these functions: > > void RAND_seed(const void *buf, int num); > > void RAND_add(const void *buf, int num, double > entropy); > > int RAND_status(void); > > int RAND_event(UINT iMsg, WPARAM wParam, LPARAM > lParam); > void RAND_screen(void); > > You need to seed PRNG before the function > RSA_generate_key(...). a good explanation you will find > in: > http://www.openssl.org/docs/crypto/RAND_add.html > > > Hi, > > I have a snippet that encrypts/decrypts using RSA. > > > > > > #include <stdio.h> > > > > #include <openssl/rsa.h> > > > > #include <string.h> > > > > // RSATest: Program illustrating Simple RSA > Encryption/Decryption > > > > int main() > > > > { > > > > char *plain="Sample text"; //Sample text (plain text) > to Encrypt/Decrypt > > > > char *ciphertext; > > > > char *plain1; > > > > int enclen,i,declen; > > > > printf("%s\n",plain); > > > > > > > > // Generate RSA key > > > > RSA *rsa1= RSA_generate_key(1024,65537,NULL,NULL); > > > > // RSA_size() will determine how much memory must be > allocated for an RSA encrypted value > > > > ciphertext = (char *)malloc(RSA_size(rsa1)); > > > > printf("RSA size %d",RSA_size(rsa1)); > > > > > > > > I am using Cygwin. My question is this....Where and > How do I seed the random number generator? > > > > Thanks, > > > > Joe > > > > > > > > > > > > --------------------------------- > > Do you Yahoo!? > > New and Improved Yahoo! Mail - Send 10MB messages! > > Leandro Barros de Figueiredo > Eng. Controle e Automação - UFMG > > ______________________________________________________________ > ____________ > Acabe com aquelas janelinhas que pulam na sua tela. > AntiPop-up UOL - É grátis! > http://antipopup.uol.com.br/ > > > ______________________________________________________________________ > OpenSSL Project http://www.openssl.org > User Support Mailing List [EMAIL PROTECTED] > Automated List Manager [EMAIL PROTECTED] > ______________________________________________________________________ OpenSSL Project http://www.openssl.org User Support Mailing List [EMAIL PROTECTED] Automated List Manager [EMAIL PROTECTED]
