On Tue, Dec 03, 2002 at 03:10:26PM +0100, Stephen Henson via RT wrote:
> What do you mean "buggy behaviour"? OpenSSL ASN1 code expects a complete
> structure only and should produce an error if it is incomplete, at least at
^^^^^^^^^^^^^^^^^^^^^^^
exactly
I mean that OpenSSL not produce any error!
My colleague sent some easy example, that demonstrates this bug.
(example is attached again)
--
Zito
#include <stdio.h>
#include <openssl/ssl.h>
#include <openssl/err.h>
#include <openssl/bio.h>
#include <openssl/asn1t.h>
#include <openssl/asn1.h>
typedef struct { // ASN1 structure for message
ASN1_INTEGER *cislo; // integer number
ASN1_IA5STRING *str; // text
} ZPRAVA;
ASN1_SEQUENCE(ZPRAVA) = {
ASN1_SIMPLE(ZPRAVA, cislo, ASN1_INTEGER),
ASN1_SIMPLE(ZPRAVA, str, ASN1_IA5STRING)
} ASN1_SEQUENCE_END(ZPRAVA)
IMPLEMENT_ASN1_FUNCTIONS(ZPRAVA)
// macro for BIO reading ZPRAVA
#define d2i_ZPRAVA_bio(b, zprava) (ZPRAVA*) ASN1_d2i_bio((char *(*)()) ZPRAVA_new,\
(char *(*)()) d2i_ZPRAVA, (b), (unsigned char **)(zprava))
ZPRAVA *read_ZPRAVA_bio(BIO *io, ZPRAVA **z)
{
// there are two posibilities, how to read
return d2i_ZPRAVA_bio(io, z);
// return ASN1_item_d2i_bio(ASN1_ITEM_rptr(ZPRAVA), io, z);
}
void write_der_file(ZPRAVA *z, char *fn, int size)
{
int len;
unsigned char *dd;
FILE *f;
dd = NULL; // converting to DER format according
len = i2d_ZPRAVA(z, &dd); // the examples from man pages
if (len < 0)
exit(1);
if ((size >= 0) && (size < len)) // if size is positive
dd[size] = '\0'; // dd is shortered to size
f = fopen(fn, "w");
fputs((char *) dd, f); // writting to a file
fclose(f);
}
int main(int argc, char *agv[])
{
ZPRAVA *z, *z1, *z2; // ASN1 structures
BIO *io; // BIO object
SSL_library_init();
SSL_load_error_strings();
z = ZPRAVA_new(); // creating a structure and filling
ASN1_INTEGER_set(z->cislo, 123);
ASN1_STRING_set(z->str, "aaaaaaaaaaaaaaaaaaaa", 20);
write_der_file(z, "test1.der", -1); // writting structure to a file
io = BIO_new_file("test1.der", "r"); // opening BIO
z1 = ZPRAVA_new();
read_ZPRAVA_bio(io, &z1); // reading from BIO
// printing to stdout
fprintf(stdout, "ASN1\nCislo: %ld\nText: %s\n\n",
ASN1_INTEGER_get(z1->cislo), (char *) ASN1_STRING_data(z1->str));
BIO_free(io);
write_der_file(z, "test2.der", 10); // writting incomplete structure
ERR_clear_error(); // clearing an error queue
io = BIO_new_file("test2.der", "r"); // opening BIO
z2 = ZPRAVA_new();
read_ZPRAVA_bio(io, &z2); // reading from BIO
ERR_print_errors_fp(stdout); // writing errors to stderr
// printing to stdout
fprintf(stdout, "ASN1\nCislo: %ld\nText: %s\n\n",
ASN1_INTEGER_get(z2->cislo), (char *) ASN1_STRING_data(z2->str));
BIO_free(io);
return 0;
}
