Re: EVP_CipherFinal()

[Aleix Conchillo]

Stella Power <[EMAIL PROTECTED]> writes:

> okidokey, the code is attached.
> The encryption/decryption function is in do_crypt.c
> 

hi,

i think you have the problem when you get the size of your buffer.

inlen = strlen(i_p);

you are treating the result as a string. this is not correct because it
could have lots of \0 characters. so strlen() will stop at the first
\0 and give you a wrong length. you must treat your buffers as buffers
with any characters not as simple strings (encrypt does not return
strings).

hope this helps.

regards,

aleix

__
OpenSSL Project http://www.openssl.org
User Support Mailing List[EMAIL PROTECTED]
Automated List Manager   [EMAIL PROTECTED]

Re: EVP_CipherFinal()

[Stella Power]

okidokey, the code is attached.
The encryption/decryption function is in do_crypt.c

thanks
Stella

On Mon, May 27, 2002 at 06:03:46PM +0200, Aleix Conchillo wrote:
> hi stella,
> 
> could you please post your sample code?
> 
> best regards,
> 
> aleix
> 
> __
> OpenSSL Project http://www.openssl.org
> User Support Mailing List[EMAIL PROTECTED]
> Automated List Manager   [EMAIL PROTECTED]


OPENSSLDIR=/usr/local/ssl
LIBS = -lm -L$(OPENSSLDIR) -lssl -lcrypto -lefence
oflags = -c
CFLAGS = -pedantic -ansi -W -Wall -g
CC = gcc
exec = crypt

default: main.o do_crypt.o parse_keyfile.o
$(CC) -o ${exec} main.o do_crypt.o parse_keyfile.o -o crypt ${LIBS}

main.o:  main.c do_crypt.c parse_keyfile.c header.h
${CC} -c ${CFLAGS} ${INCDIR} main.c do_crypt.c parse_keyfile.c


clean:
rm -f core *.o


#include "header.h"

#define EVP_MAX_BLOCK_LENGTH 6
FILE *out;


char* do_crypt(char *i_p, int docrypt) {

unsigned char outbuf[1024+EVP_MAX_BLOCK_LENGTH];
unsigned char outbuf_final[1024];
int outlen, inlen;
unsigned char iv[] = "12345678";

EVP_CIPHER_CTX ctx;

inlen = strlen(i_p);
EVP_CIPHER_CTX_init(&ctx);
EVP_CipherInit(&ctx, EVP_des_ede3(), NULL, NULL, docrypt);
EVP_CIPHER_CTX_set_key_length(&ctx, key_length);
EVP_CipherInit(&ctx, NULL, key, iv, docrypt);
if(!EVP_CipherUpdate(&ctx, outbuf, &outlen, (unsigned char *)i_p, inlen)) {
fprintf(stderr, "Error crypting in EVP_CipherUpdate\n");
exit(10);
}
if(!EVP_CipherFinal(&ctx, outbuf_final, &outlen)) {
fprintf(stderr, "Error crypting in EVP_CipherFinal\n");
exit(11);
}
sprintf(return_out,"%s%s", outbuf, outbuf_final);
fwrite(return_out,1,outlen, stdout);
fwrite("\n",1,1,stdout);

EVP_CIPHER_CTX_cleanup(&ctx);
return return_out;
}


#include 
#include 
#include 
#include 
#include 
#include 
#include 
#include 
#include 
#include 
#include 
#include 
#include 
#include 

#define BUFSIZE 1024

struct stat tmp;

int f_map_encrypt_p;
FILE *f_session_key_p;

char *session_key_filename;

char *current_line;

char *edata_a, *edata_b;
char *data_a, *data_b;

int docrypt;
int key_length;
char *session_key;
unsigned char key[BUFSIZE];
char *return_out;

char* parse_keyfile(char *current_line);
char* do_crypt(char *i_p, int docrypt);


key : 64556564446546465546546444555665
   
   
   


#include "header.h"


int main(int argc, char** argv) {

int opt, i=0, j=0;
char *temp2;


/* COMMAND LINE OPTION HANDLING */
while((opt = getopt(argc, argv, "k:a:b:"))!=-1)
switch (opt) {
case 'k':
if(optarg) {
session_key_filename = malloc(64);
strncpy(session_key_filename, optarg, 64);
if((stat(optarg, &tmp)!=0)) {
fprintf(stderr,"Error: Illegal 
filename for keyfile\n");
exit(1);
}
}
break;
case 'a':
if(optarg) {
edata_a = malloc(64);
strncpy(edata_a, optarg, 64);
}
break;
case 'b':
if(optarg) {
edata_b = malloc(64);
strncpy(edata_b, optarg, 64);
}
break;
case '?':
default:
printf("Usage: -k session_key_file\n");
exit(2);
}


printf("0: %s\t1: %s\n", edata_a, edata_b);


if (!session_key_filename) {
fprintf(stderr, "Error: Missing option -k\n");
printf("Usage: -k session_key_file\n");
exit(4);
}



if((return_out =(char *)malloc((BUFSIZE)*sizeof(char)))==NULL) {
fprintf(stderr, "Error: malloc error\n");
exit(8);
}




/* IN HERE GOES DECRYPTION