openssh/fingerprint.c

40 lines
947 B
C

#include "includes.h"
RCSID("$Id: fingerprint.c,v 1.1 1999/11/16 22:49:28 markus Exp $");
#include "ssh.h"
#include "xmalloc.h"
#include <ssl/md5.h>
#define FPRINT "%02x:%02x:%02x:%02x:%02x:%02x:%02x:%02x:%02x:%02x:%02x:%02x:%02x:%02x:%02x:%02x"
/* Generate key fingerprint in ascii format.
Based on ideas and code from Bjoern Groenvall <bg@sics.se> */
char *
fingerprint(BIGNUM *e, BIGNUM *n)
{
static char retval[80];
MD5_CTX md;
unsigned char d[16];
char *buf;
int nlen, elen;
nlen = BN_num_bytes(n);
elen = BN_num_bytes(e);
buf = xmalloc(nlen + elen);
BN_bn2bin(n, buf);
BN_bn2bin(e, buf + nlen);
MD5_Init(&md);
MD5_Update(&md, buf, nlen + elen);
MD5_Final(d, &md);
snprintf(retval, sizeof(retval), FPRINT,
d[0], d[1], d[2], d[3], d[4], d[5], d[6], d[7],
d[8], d[9], d[10], d[11], d[12], d[13], d[14], d[15]);
memset(buf, 0, nlen + elen);
xfree(buf);
return retval;
}