On 9/24/05, Saber Zrelli <[EMAIL PROTECTED]> wrote:
you are not allocating memory for res; so it will result in seg fault.
either chage it to a staic array or malloc. :-),
I found where is the mistake ,
I forgot to initialize n to 0 in
DES_cfb64_encrypt(Msg, Res,20, &schedule, &Key2, &n, DES_ENCRYPT);
Thanks any way,
Saber.
* On 05:35, Sat 24 Sep 05, Saber Zrelli wrote:
> Hi ,
>
> Thanks Nils for the tip,
>
> I could make my code run, but the results are not what I expect :S
> The encryption works fine, after trying to decrypt using the same
> key. I dont find the initial string. I dont see where is my mistake.
>
> I attached a compilable source file.
>
> Regards,
> Saber.
>
>
>
>
> * On 20:33, Fri 23 Sep 05, Nils Larsch wrote:
> > Saber Zrelli wrote:
> > > Hi ,
> > >
> > > I am trying to use openssl's crypto library to encrypt packets
> > > before transmitting them into a TCP connection.
> > >
> > > I have some difficulties on using DES funcions.
> > >
> > > below is the code I wrote, it compiles but core-dump occurs at line 48.
> > >
> > >
> > > char *
> > > 35 Encrypt(int Etype, char *Key, void *Msg)
> > > 36 {
> > > 37
> > > 38 >_______char *CypherText;
> > > 39 >_______char *dec;
> > > 40 >_______int *n;
> > > 41
> > > 42 >_______DES_cblock>_____Key2;
> > > 43 >_______DES_key_schedule *schedule;
> > > 44
> > > 45
> > > 46 >_______memcpy(Key2, Key, 8);
> > > 47 >_______DES_set_odd_parity(&Key2);
> > > 48 >_______DES_set_key_checked(&Key2, schedule);
> >
> > the schedule pointer is uninitialzed => core dump, as schedule
> > is used in DES_set_key_unchecked (called by DES_set_key_checked).
> > Try to do something like:
> > DES_key_schedule schedule;
> > ...
> > DES_set_key_checked(&Key2, &schedule);
> >
> > > 49 >_______DES_cfb64_encrypt((char *)Msg, CypherText, strlen(Msg), schedule, &Key2, n, 1);
> > > 50 >_______printf("Encrypted message : %s\n", CypherText);
> > > 51 >_______DES_cfb64_encrypt(CypherText, dec, strlen(Msg), schedule, &Key2, n, 0);
> > > 52 >_______printf("decrypted message : %s\n", dec);
> > >
> > >
> > > Any help links to sample code is appreciated.
> >
> > perhaps crypto/des/destest.c
> >
> > Cheers,
> > Nils
> > ______________________________________________________________________
> > OpenSSL Project http://www.openssl.org
> > User Support Mailing List openssl-users@openssl.org
> > Automated List Manager [EMAIL PROTECTED]
>
> --
> Saber ZRELLI <[EMAIL PROTECTED]>
> Japan Advanced Institute of Science and Technology
> Center of Information Science
> Shinoda Laboratory
> url : http://www.jaist.ac.jp/~zrelli
> gpg-id : 0x7119EA78
> #include <time.h>
> #include <stdio.h>
> #include <unistd.h>
> #include <openssl/des.h>
>
>
> char *
> Decrypt(char *Key, void *Msg)
> {
>
>
> static char dec [30];
> int n;
>
> DES_cblock Key2;
> DES_key_schedule schedule;
>
> memcpy(Key2, Key, 8);
> DES_set_odd_parity(&Key2);
> DES_set_key_checked(&Key2, &schedule);
> n = 0;
> DES_cfb64_encrypt((char *)Msg, dec, strlen((char *)Msg), &schedule, &Key2,
> &n, DES_DECRYPT);
> printf("decrypted message : %s\n", dec);
>
> return (dec);
>
>
> }
>
> char *
> Encrypt(char *Key, void *Msg)
> {
>
> char *Res;
you are not allocating memory for res; so it will result in seg fault.
either chage it to a staic array or malloc. :-),
> int n;
>
> DES_cblock Key2;
> DES_key_schedule schedule;
>
> memcpy(Key2, Key, 8);
> DES_set_odd_parity(&Key2);
> DES_set_key_checked(&Key2, &schedule);
> DES_cfb64_encrypt((char *)Msg, Res, strlen((char *)Msg),
> &schedule, &Key2, &n, DES_ENCRYPT);
> printf("Encrypted message : %s\n", Res);
>
>
> return (Res);
> }
>
>
> int
> main()
> {
>
> char Msg [20];
> char *res;
>
> strcpy(Msg, "KKKKKKBB");
> res = Encrypt("123456789778", Msg);
> Decrypt("123456789778", res);
>
> return (0);
>
> }
