Code_t
ZReadAscii16(char *ptr,
int len,
unsigned short *value_ptr)
{
unsigned char buf[2];
Code_t retval;
retval = ZReadAscii(ptr, len, buf, 2);
if (retval != ZERR_NONE)
return retval;
*value_ptr = (buf[0] << 8) | buf[1];
return ZERR_NONE;
}
static Code_t
ZCheckAuthentication4(ZNotice_t *notice,
struct sockaddr_in *from)
{
int result;
char srcprincipal[ANAME_SZ+INST_SZ+REALM_SZ+4];
KTEXT_ST authent;
AUTH_DAT dat;
ZChecksum_t checksum;
char instance[INST_SZ+1];
if (!notice->z_auth)
return ZAUTH_NO;
/* Check for bogus authentication data length. */
if (notice->z_authent_len <= 0)
return ZAUTH_FAILED;
/* Read in the authentication data. */
if (ZReadAscii(notice->z_ascii_authent,
strlen(notice->z_ascii_authent)+1,
(unsigned char *)authent.dat,
notice->z_authent_len) == ZERR_BADFIELD) {
return ZAUTH_FAILED;
}
authent.length = notice->z_authent_len;
strcpy(instance, SERVER_INSTANCE);
/* We don't have the session key cached; do it the long way. */
result = krb_rd_req(&authent, SERVER_SERVICE, instance,
from->sin_addr.s_addr, &dat, srvtab_file);
if (result == RD_AP_OK) {
ZSetSessionDES(&dat.session);
sprintf(srcprincipal, "%s%s%s@%s", dat.pname, dat.pinst[0] ? "." : "",
dat.pinst, dat.prealm);
if (strcmp(srcprincipal, notice->z_sender))
return ZAUTH_FAILED;
} else {
return ZAUTH_FAILED; /* didn't decode correctly */
}
/* Check the cryptographic checksum. */
checksum = compute_checksum(notice, dat.session);
if (checksum != notice->z_checksum)
return ZAUTH_FAILED;
return ZAUTH_YES;
}
Code_t
ZReadAscii32(char *ptr,
int len,
unsigned long *value_ptr)
{
unsigned char buf[4];
Code_t retval;
retval = ZReadAscii(ptr, len, buf, 4);
if (retval != ZERR_NONE)
return retval;
*value_ptr = (buf[0] << 24) | (buf[1] << 16) | (buf[2] << 8) | buf[3];
return ZERR_NONE;
}
Code_t
ZParseNotice(char *buffer,
int len,
ZNotice_t *notice)
{
char *ptr, *end;
unsigned long temp;
int maj, numfields, i;
#ifndef __LINE__
#define __LINE__ -1
#endif
#define BAD_PACKET(what) return _bad_packet(__LINE__, ptr, notice, what)
(void) memset((char *)notice, 0, sizeof(ZNotice_t));
ptr = buffer;
end = buffer+len;
notice->z_packet = buffer;
notice->z_version = ptr;
if (strncmp(ptr, ZVERSIONHDR, sizeof(ZVERSIONHDR) - 1))
return (ZERR_VERS);
ptr += sizeof(ZVERSIONHDR) - 1;
if (!*ptr)
BAD_PACKET("null version string");
maj = atoi(ptr);
if (maj != ZVERSIONMAJOR)
return (ZERR_VERS);
ptr = next_field(ptr, end);
if (ZReadAscii32(ptr, end-ptr, &temp) == ZERR_BADFIELD)
BAD_PACKET("parsing num_hdr_fields");
numfields = temp;
notice->z_num_hdr_fields = numfields;
ptr = next_field(ptr, end);
/*XXX 3 */
numfields -= 2; /* numfields, version, and checksum */
if (numfields < 0)
BAD_PACKET("no header fields");
if (numfields && ptr < end) {
if (ZReadAscii32(ptr, end-ptr, &temp) == ZERR_BADFIELD)
BAD_PACKET("parsing kind");
notice->z_kind = (ZNotice_Kind_t)temp;
numfields--;
ptr = next_field(ptr, end);
}
else
BAD_PACKET("missing kind");
if (numfields && ptr < end) {
if (ZReadAscii(ptr, end-ptr, (unsigned char *)¬ice->z_uid,
sizeof(ZUnique_Id_t)) == ZERR_BADFIELD)
BAD_PACKET("parsing uid");
notice->z_time.tv_sec = ntohl((u_long) notice->z_uid.tv.tv_sec);
notice->z_time.tv_usec = ntohl((u_long) notice->z_uid.tv.tv_usec);
numfields--;
ptr = next_field(ptr, end);
}
else
BAD_PACKET("missing uid");
if (numfields && ptr < end) {
if (ZReadAscii16(ptr, end-ptr, ¬ice->z_port) == ZERR_BADFIELD)
BAD_PACKET("parsing port");
notice->z_port = htons(notice->z_port);
numfields--;
ptr = next_field(ptr, end);
}
else
BAD_PACKET("missing port");
if (numfields && ptr < end) {
if (ZReadAscii32(ptr, end-ptr, &temp) == ZERR_BADFIELD)
BAD_PACKET("parsing auth");
notice->z_auth = temp;
numfields--;
ptr = next_field(ptr, end);
}
else
BAD_PACKET("missing auth");
notice->z_checked_auth = ZAUTH_UNSET;
if (numfields && ptr < end) {
if (ZReadAscii32(ptr, end-ptr, &temp) == ZERR_BADFIELD)
BAD_PACKET("parsing authenticator length");
notice->z_authent_len = temp;
numfields--;
ptr = next_field(ptr, end);
}
else
BAD_PACKET("missing authenticator length");
if (numfields && ptr < end) {
notice->z_ascii_authent = ptr;
numfields--;
ptr = next_field(ptr, end);
}
else
BAD_PACKET("missing authenticator field");
if (numfields && ptr < end) {
notice->z_class = ptr;
numfields--;
ptr = next_field(ptr, end);
}
else
notice->z_class = "";
if (numfields && ptr < end) {
notice->z_class_inst = ptr;
numfields--;
ptr = next_field(ptr, end);
}
else
notice->z_class_inst = "";
if (numfields && ptr < end) {
notice->z_opcode = ptr;
numfields--;
ptr = next_field(ptr, end);
}
else
notice->z_opcode = "";
if (numfields && ptr < end) {
notice->z_sender = ptr;
numfields--;
ptr = next_field(ptr, end);
}
else
notice->z_sender = "";
if (numfields && ptr < end) {
notice->z_recipient = ptr;
numfields--;
ptr = next_field(ptr, end);
}
else
notice->z_recipient = "";
if (numfields && ptr < end) {
notice->z_default_format = ptr;
numfields--;
ptr = next_field(ptr, end);
}
else
notice->z_default_format = "";
if (numfields && ptr < end) {
notice->z_ascii_checksum = ptr;
if (ZReadAscii32(ptr, end-ptr, &temp) == ZERR_BADFIELD)
notice->z_checksum = 0;
else
notice->z_checksum = temp;
numfields--;
ptr = next_field (ptr, end);
}
else
{
notice->z_ascii_checksum = "";
notice->z_checksum = 0;
}
if (numfields && ptr < end) {
notice->z_multinotice = ptr;
numfields--;
ptr = next_field(ptr, end);
}
else
notice->z_multinotice = "";
if (numfields && ptr < end) {
if (ZReadAscii(ptr, end-ptr, (unsigned char *)¬ice->z_multiuid,
sizeof(ZUnique_Id_t)) == ZERR_BADFIELD)
BAD_PACKET("parsing multiuid");
notice->z_time.tv_sec = ntohl((u_long) notice->z_multiuid.tv.tv_sec);
notice->z_time.tv_usec = ntohl((u_long) notice->z_multiuid.tv.tv_usec);
numfields--;
ptr = next_field(ptr, end);
}
else
notice->z_multiuid = notice->z_uid;
if (numfields && ptr < end) {
/* we will take it on faith that ipv6 addresses are longer than ipv4
addresses */
unsigned char addrbuf[sizeof(notice->z_sender_sockaddr.ip6.sin6_addr)];
int alen;
/* because we're paranoid about naughtily misformatted packets */
if (memchr(ptr, '\0', end - ptr) == NULL)
BAD_PACKET("unterminated address field");
if (*ptr == 'Z') {
if (ZReadZcode((unsigned char *)ptr, addrbuf,
sizeof(addrbuf), &alen) == ZERR_BADFIELD)
BAD_PACKET("parsing Zcode address");
} else {
alen = sizeof(notice->z_sender_sockaddr.ip4.sin_addr);
if (ZReadAscii(ptr, end - ptr, (unsigned char *)addrbuf,
alen) == ZERR_BADFIELD)
BAD_PACKET("parsing NetASCII address");
}
if (alen == sizeof(notice->z_sender_sockaddr.ip6.sin6_addr)) {
notice->z_sender_sockaddr.ip6.sin6_family = AF_INET6;
memcpy(¬ice->z_sender_sockaddr.ip6.sin6_addr, addrbuf, alen);
#ifdef HAVE_SOCKADDR_IN6_SIN6_LEN
notice->z_sender_sockaddr.ip6.sin6_len = sizeof(notice->z_sender_sockaddr.ip6);
#endif
} else if (alen == sizeof(notice->z_sender_sockaddr.ip4.sin_addr)) {
notice->z_sender_sockaddr.ip4.sin_family = AF_INET;
memcpy(¬ice->z_sender_sockaddr.ip4.sin_addr, addrbuf, alen);
#ifdef HAVE_SOCKADDR_IN_SIN_LEN
notice->z_sender_sockaddr.ip4.sin_len = sizeof(notice->z_sender_sockaddr.ip4);
#endif
} else
BAD_PACKET("address claims to be neither IPv4 or IPv6");
numfields--;
ptr = next_field(ptr, end);
} else {
memset(¬ice->z_sender_sockaddr, 0,
sizeof notice->z_sender_sockaddr);
notice->z_sender_sockaddr.ip4.sin_family = AF_INET;
notice->z_sender_sockaddr.ip4.sin_addr = notice->z_uid.zuid_addr;
#ifdef HAVE_SOCKADDR_IN_SIN_LEN
notice->z_sender_sockaddr.ip4.sin_len = sizeof(notice->z_sender_sockaddr.ip4);
#endif
}
if (numfields && ptr < end) {
if (ZReadAscii16(ptr, end-ptr, ¬ice->z_charset) == ZERR_BADFIELD)
BAD_PACKET("parsing charset");
notice->z_charset = htons(notice->z_charset);
numfields--;
ptr = next_field(ptr, end);
} else
notice->z_charset = ZCHARSET_UNKNOWN;
for (i=0;ptr < end && i<Z_MAXOTHERFIELDS && numfields;i++,numfields--) {
notice->z_other_fields[i] = ptr;
ptr = next_field(ptr, end);
}
notice->z_num_other_fields = i;
for (i=0;ptr < end && numfields;numfields--)
ptr = next_field(ptr, end);
if (numfields || *(ptr - 1) != '\0')
BAD_PACKET("end of headers");
notice->z_message = (void *)ptr;
notice->z_message_len = len-(ptr-buffer);
return (ZERR_NONE);
}
