int32_t
krb_rd_safe(void *in, u_int32_t in_length, des_cblock *key,
struct sockaddr_in *sender, struct sockaddr_in *receiver,
MSG_DAT *m_data)
{
unsigned char *p = (unsigned char*)in, *start;
unsigned char pvno, type;
int little_endian;
struct timeval tv;
u_int32_t src_addr;
int delta_t;
pvno = *p++;
if(pvno != KRB_PROT_VERSION)
return RD_AP_VERSION;
type = *p++;
little_endian = type & 1;
type &= ~1;
if(type != AUTH_MSG_SAFE)
return RD_AP_MSG_TYPE;
start = p;
p += krb_get_int(p, &m_data->app_length, 4, little_endian);
if(m_data->app_length + 31 > in_length)
return RD_AP_MODIFIED;
m_data->app_data = p;
p += m_data->app_length;
m_data->time_5ms = *p++;
p += krb_get_address(p, &src_addr);
if (!krb_equiv(src_addr, sender->sin_addr.s_addr))
return RD_AP_BADD;
p += krb_get_int(p, (u_int32_t *)&m_data->time_sec, 4, little_endian);
m_data->time_sec = lsb_time(m_data->time_sec, sender, receiver);
gettimeofday(&tv, NULL);
delta_t = abs((int)((long) tv.tv_sec - m_data->time_sec));
if (delta_t > CLOCK_SKEW) return RD_AP_TIME;
/*
* caller must check timestamps for proper order and replays, since
* server might have multiple clients each with its own timestamps
* and we don't assume tightly synchronized clocks.
*/
{
unsigned char new_checksum[16];
unsigned char old_checksum[16];
fixup_quad_cksum(start, p - start, key,
new_checksum, old_checksum, little_endian);
if((dqc_type == DES_QUAD_GUESS || dqc_type == DES_QUAD_NEW) &&
memcmp(new_checksum, p, 16) == 0)
dqc_type = DES_QUAD_NEW;
else if((dqc_type == DES_QUAD_GUESS || dqc_type == DES_QUAD_OLD) &&
memcmp(old_checksum, p, 16) == 0)
dqc_type = DES_QUAD_OLD;
else
return RD_AP_MODIFIED;
}
return KSUCCESS;
}
int32_t
krb_rd_priv(void *in, u_int32_t in_length,
struct des_ks_struct *schedule, des_cblock *key,
struct sockaddr_in *sender, struct sockaddr_in *receiver,
MSG_DAT *m_data)
{
unsigned char *p = (unsigned char*)in;
int little_endian;
u_int32_t clen;
struct timeval tv;
u_int32_t src_addr;
int delta_t;
unsigned char pvno, type;
pvno = *p++;
if(pvno != KRB_PROT_VERSION)
return RD_AP_VERSION;
type = *p++;
little_endian = type & 1;
type &= ~1;
p += krb_get_int(p, &clen, 4, little_endian);
if(clen + 2 > in_length)
return RD_AP_MODIFIED;
des_pcbc_encrypt((des_cblock*)p, (des_cblock*)p, clen,
schedule, key, DES_DECRYPT);
p += krb_get_int(p, &m_data->app_length, 4, little_endian);
if(m_data->app_length + 17 > in_length)
return RD_AP_MODIFIED;
m_data->app_data = p;
p += m_data->app_length;
m_data->time_5ms = *p++;
p += krb_get_address(p, &src_addr);
if (!krb_equiv(src_addr, sender->sin_addr.s_addr))
return RD_AP_BADD;
p += krb_get_int(p, (u_int32_t *)&m_data->time_sec, 4, little_endian);
m_data->time_sec = lsb_time(m_data->time_sec, sender, receiver);
gettimeofday(&tv, NULL);
/* check the time integrity of the msg */
delta_t = abs((int)((long) tv.tv_sec - m_data->time_sec));
if (delta_t > CLOCK_SKEW)
return RD_AP_TIME;
if (krb_debug)
krb_warning("delta_t = %d\n", (int) delta_t);
/*
* caller must check timestamps for proper order and
* replays, since server might have multiple clients
* each with its own timestamps and we don't assume
* tightly synchronized clocks.
*/
return KSUCCESS;
}
