linux/fs/cifs/asn1.c
Hyunchul Lee 0475c3655e cifs: decoding negTokenInit with generic ASN1 decoder
Decode negTokenInit with lib/asn1_decoder. For that,
add OIDs in linux/oid_registry.h and a negTokenInit
ASN1 file, "spnego_negtokeninit.asn1".
And define decoder's callback functions, which
are the gssapi_this_mech for checking SPENGO oid and
the neg_token_init_mech_type for getting authentication
mechanisms supported by a server.

Signed-off-by: Hyunchul Lee <hyc.lee@gmail.com>
Reviewed-by: Aurelien Aptel <aaptel@suse.com>
Reviewed-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Signed-off-by: Steve French <stfrench@microsoft.com>
2021-06-20 21:28:17 -05:00

64 lines
1.4 KiB
C

// SPDX-License-Identifier: GPL-2.0-or-later
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/oid_registry.h>
#include "cifsglob.h"
#include "cifs_debug.h"
#include "cifsproto.h"
#include "cifs_spnego_negtokeninit.asn1.h"
int
decode_negTokenInit(unsigned char *security_blob, int length,
struct TCP_Server_Info *server)
{
if (asn1_ber_decoder(&cifs_spnego_negtokeninit_decoder, server,
security_blob, length) == 0)
return 1;
else
return 0;
}
int cifs_gssapi_this_mech(void *context, size_t hdrlen,
unsigned char tag, const void *value, size_t vlen)
{
enum OID oid;
oid = look_up_OID(value, vlen);
if (oid != OID_spnego) {
char buf[50];
sprint_oid(value, vlen, buf, sizeof(buf));
cifs_dbg(FYI, "Error decoding negTokenInit header: unexpected OID %s\n",
buf);
return -EBADMSG;
}
return 0;
}
int cifs_neg_token_init_mech_type(void *context, size_t hdrlen,
unsigned char tag,
const void *value, size_t vlen)
{
struct TCP_Server_Info *server = context;
enum OID oid;
oid = look_up_OID(value, vlen);
if (oid == OID_mskrb5)
server->sec_mskerberos = true;
else if (oid == OID_krb5u2u)
server->sec_kerberosu2u = true;
else if (oid == OID_krb5)
server->sec_kerberos = true;
else if (oid == OID_ntlmssp)
server->sec_ntlmssp = true;
else {
char buf[50];
sprint_oid(value, vlen, buf, sizeof(buf));
cifs_dbg(FYI, "Decoding negTokenInit: unsupported OID %s\n",
buf);
}
return 0;
}