[PATCH v4] cifs: decoding negTokenInit with generic ASN1 decoder

Steve French smfrench at gmail.com
Sun Jun 6 07:11:36 UTC 2021


"make M=fs/cifs"  from the top of the kernel tree worked, but my usual
script failed

"cd fs/cifs"
then
"make C=1 -C /usr/src/linux-headers-`uname -r` M=`pwd` modules
CF=-D__CHECK_ENDIAN__"

failed with (even after generating the files with the "make M=fs/cifs" earlier):

ASN.1   /home/smfrench/cifs-2.6/fs/cifs/spnego_negtokeninit.asn1.[ch]
  CC [M]  /home/smfrench/cifs-2.6/fs/cifs/asn1.o
/home/smfrench/cifs-2.6/fs/cifs/asn1.c: In function ‘gssapi_this_mech’:
/home/smfrench/cifs-2.6/fs/cifs/asn1.c:28:13: error: ‘OID_spnego’
undeclared (first use in this function)
   28 |  if (oid != OID_spnego) {
      |             ^~~~~~~~~~
/home/smfrench/cifs-2.6/fs/cifs/asn1.c:28:13: note: each undeclared
identifier is reported only once for each function it appears in
/home/smfrench/cifs-2.6/fs/cifs/asn1.c: In function ‘neg_token_init_mech_type’:
/home/smfrench/cifs-2.6/fs/cifs/asn1.c:47:13: error: ‘OID_mskrb5’
undeclared (first use in this function); did you mean ‘OID_md5’?
   47 |  if (oid == OID_mskrb5)
      |             ^~~~~~~~~~
      |             OID_md5
/home/smfrench/cifs-2.6/fs/cifs/asn1.c:49:18: error: ‘OID_krb5u2u’
undeclared (first use in this function)
   49 |  else if (oid == OID_krb5u2u)
      |                  ^~~~~~~~~~~
/home/smfrench/cifs-2.6/fs/cifs/asn1.c:51:18: error: ‘OID_krb5’
undeclared (first use in this function)
   51 |  else if (oid == OID_krb5)
      |                  ^~~~~~~~
/home/smfrench/cifs-2.6/fs/cifs/asn1.c:53:18: error: ‘OID_ntlmssp’
undeclared (first use in this function)
   53 |  else if (oid == OID_ntlmssp)
      |                  ^~~~~~~~~~~
make[1]: *** [scripts/Makefile.build:272:
/home/smfrench/cifs-2.6/fs/cifs/asn1.o] Error 1
make: *** [Makefile:1845: /home/smfrench/cifs-2.6/fs/cifs] Error 2
make: Leaving directory
'/usr/src/linux-headers-5.13.0-051300rc3daily20210526-generic

On Sat, Jun 5, 2021 at 8:07 PM Hyunchul Lee <hyc.lee at gmail.com> wrote:
>
> 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 at gmail.com>
> ---
> changes from v3:
>  - Change Makefile to fix a compile error, "spnego_negtokeninit.asn1.h: No such file or directory".
> changes from v2:
>  - Change Makefile to fix a compile error(kernel test bot).
>  - Add cifsproto.h into asn1.c to fix a compile warning(kernel test bot).
> chnages from v1:
>  - Select CONFIG_OID_REGISTRY
>
>  fs/cifs/Kconfig                  |   2 +
>  fs/cifs/Makefile                 |   8 +-
>  fs/cifs/asn1.c                   | 623 ++-----------------------------
>  fs/cifs/spnego_negtokeninit.asn1 |  40 ++
>  include/linux/oid_registry.h     |   8 +
>  5 files changed, 93 insertions(+), 588 deletions(-)
>  create mode 100644 fs/cifs/spnego_negtokeninit.asn1
>
> diff --git a/fs/cifs/Kconfig b/fs/cifs/Kconfig
> index bf52e9326ebe..7de5c893c181 100644
> --- a/fs/cifs/Kconfig
> +++ b/fs/cifs/Kconfig
> @@ -19,6 +19,8 @@ config CIFS
>         select CRYPTO_LIB_DES
>         select KEYS
>         select DNS_RESOLVER
> +       select ASN1
> +       select OID_REGISTRY
>         help
>           This is the client VFS module for the SMB3 family of NAS protocols,
>           (including support for the most recent, most secure dialect SMB3.1.1)
> diff --git a/fs/cifs/Makefile b/fs/cifs/Makefile
> index 3ee3b7de4ded..9d877eafd350 100644
> --- a/fs/cifs/Makefile
> +++ b/fs/cifs/Makefile
> @@ -6,12 +6,16 @@ ccflags-y += -I$(src)         # needed for trace events
>  obj-$(CONFIG_CIFS) += cifs.o
>
>  cifs-y := trace.o cifsfs.o cifssmb.o cifs_debug.o connect.o dir.o file.o \
> -         inode.o link.o misc.o netmisc.o smbencrypt.o transport.o asn1.o \
> +         inode.o link.o misc.o netmisc.o smbencrypt.o transport.o \
>           cifs_unicode.o nterr.o cifsencrypt.o \
>           readdir.o ioctl.o sess.o export.o smb1ops.o unc.o winucase.o \
>           smb2ops.o smb2maperror.o smb2transport.o \
>           smb2misc.o smb2pdu.o smb2inode.o smb2file.o cifsacl.o fs_context.o \
> -         dns_resolve.o
> +         dns_resolve.o spnego_negtokeninit.asn1.o asn1.o
> +
> +$(obj)/asn1.o: $(obj)/spnego_negtokeninit.asn1.h
> +
> +$(obj)/spnego_negtokeninit.asn1.o: $(obj)/spnego_negtokeninit.asn1.c $(obj)/spnego_negtokeninit.asn1.h
>
>  cifs-$(CONFIG_CIFS_XATTR) += xattr.o
>
> diff --git a/fs/cifs/asn1.c b/fs/cifs/asn1.c
> index 3150c19cdc2f..2db95fe3abfb 100644
> --- a/fs/cifs/asn1.c
> +++ b/fs/cifs/asn1.c
> @@ -1,612 +1,63 @@
>  // SPDX-License-Identifier: GPL-2.0-or-later
> -/*
> - * The ASB.1/BER parsing code is derived from ip_nat_snmp_basic.c which was in
> - * turn derived from the gxsnmp package by Gregory McLean & Jochen Friedrich
> - *
> - * Copyright (c) 2000 RP Internet (www.rpi.net.au).
> - */
>
>  #include <linux/module.h>
> -#include <linux/types.h>
>  #include <linux/kernel.h>
> -#include <linux/mm.h>
> -#include <linux/slab.h>
> -#include "cifspdu.h"
> +#include <linux/oid_registry.h>
>  #include "cifsglob.h"
>  #include "cifs_debug.h"
>  #include "cifsproto.h"
> +#include "spnego_negtokeninit.asn1.h"
>
> -/*****************************************************************************
> - *
> - * Basic ASN.1 decoding routines (gxsnmp author Dirk Wisse)
> - *
> - *****************************************************************************/
> -
> -/* Class */
> -#define ASN1_UNI       0       /* Universal */
> -#define ASN1_APL       1       /* Application */
> -#define ASN1_CTX       2       /* Context */
> -#define ASN1_PRV       3       /* Private */
> -
> -/* Tag */
> -#define ASN1_EOC       0       /* End Of Contents or N/A */
> -#define ASN1_BOL       1       /* Boolean */
> -#define ASN1_INT       2       /* Integer */
> -#define ASN1_BTS       3       /* Bit String */
> -#define ASN1_OTS       4       /* Octet String */
> -#define ASN1_NUL       5       /* Null */
> -#define ASN1_OJI       6       /* Object Identifier  */
> -#define ASN1_OJD       7       /* Object Description */
> -#define ASN1_EXT       8       /* External */
> -#define ASN1_ENUM      10      /* Enumerated */
> -#define ASN1_SEQ       16      /* Sequence */
> -#define ASN1_SET       17      /* Set */
> -#define ASN1_NUMSTR    18      /* Numerical String */
> -#define ASN1_PRNSTR    19      /* Printable String */
> -#define ASN1_TEXSTR    20      /* Teletext String */
> -#define ASN1_VIDSTR    21      /* Video String */
> -#define ASN1_IA5STR    22      /* IA5 String */
> -#define ASN1_UNITIM    23      /* Universal Time */
> -#define ASN1_GENTIM    24      /* General Time */
> -#define ASN1_GRASTR    25      /* Graphical String */
> -#define ASN1_VISSTR    26      /* Visible String */
> -#define ASN1_GENSTR    27      /* General String */
> -
> -/* Primitive / Constructed methods*/
> -#define ASN1_PRI       0       /* Primitive */
> -#define ASN1_CON       1       /* Constructed */
> -
> -/*
> - * Error codes.
> - */
> -#define ASN1_ERR_NOERROR               0
> -#define ASN1_ERR_DEC_EMPTY             2
> -#define ASN1_ERR_DEC_EOC_MISMATCH      3
> -#define ASN1_ERR_DEC_LENGTH_MISMATCH   4
> -#define ASN1_ERR_DEC_BADVALUE          5
> -
> -#define SPNEGO_OID_LEN 7
> -#define NTLMSSP_OID_LEN  10
> -#define KRB5_OID_LEN  7
> -#define KRB5U2U_OID_LEN  8
> -#define MSKRB5_OID_LEN  7
> -static unsigned long SPNEGO_OID[7] = { 1, 3, 6, 1, 5, 5, 2 };
> -static unsigned long NTLMSSP_OID[10] = { 1, 3, 6, 1, 4, 1, 311, 2, 2, 10 };
> -static unsigned long KRB5_OID[7] = { 1, 2, 840, 113554, 1, 2, 2 };
> -static unsigned long KRB5U2U_OID[8] = { 1, 2, 840, 113554, 1, 2, 2, 3 };
> -static unsigned long MSKRB5_OID[7] = { 1, 2, 840, 48018, 1, 2, 2 };
> -
> -/*
> - * ASN.1 context.
> - */
> -struct asn1_ctx {
> -       int error;              /* Error condition */
> -       unsigned char *pointer; /* Octet just to be decoded */
> -       unsigned char *begin;   /* First octet */
> -       unsigned char *end;     /* Octet after last octet */
> -};
> -
> -/*
> - * Octet string (not null terminated)
> - */
> -struct asn1_octstr {
> -       unsigned char *data;
> -       unsigned int len;
> -};
> -
> -static void
> -asn1_open(struct asn1_ctx *ctx, unsigned char *buf, unsigned int len)
> -{
> -       ctx->begin = buf;
> -       ctx->end = buf + len;
> -       ctx->pointer = buf;
> -       ctx->error = ASN1_ERR_NOERROR;
> -}
> -
> -static unsigned char
> -asn1_octet_decode(struct asn1_ctx *ctx, unsigned char *ch)
> -{
> -       if (ctx->pointer >= ctx->end) {
> -               ctx->error = ASN1_ERR_DEC_EMPTY;
> -               return 0;
> -       }
> -       *ch = *(ctx->pointer)++;
> -       return 1;
> -}
> -
> -#if 0 /* will be needed later by spnego decoding/encoding of ntlmssp */
> -static unsigned char
> -asn1_enum_decode(struct asn1_ctx *ctx, __le32 *val)
> -{
> -       unsigned char ch;
> -
> -       if (ctx->pointer >= ctx->end) {
> -               ctx->error = ASN1_ERR_DEC_EMPTY;
> -               return 0;
> -       }
> -
> -       ch = *(ctx->pointer)++; /* ch has 0xa, ptr points to length octet */
> -       if ((ch) == ASN1_ENUM)  /* if ch value is ENUM, 0xa */
> -               *val = *(++(ctx->pointer)); /* value has enum value */
> -       else
> -               return 0;
> -
> -       ctx->pointer++;
> -       return 1;
> -}
> -#endif
> -
> -static unsigned char
> -asn1_tag_decode(struct asn1_ctx *ctx, unsigned int *tag)
> -{
> -       unsigned char ch;
> -
> -       *tag = 0;
> -
> -       do {
> -               if (!asn1_octet_decode(ctx, &ch))
> -                       return 0;
> -               *tag <<= 7;
> -               *tag |= ch & 0x7F;
> -       } while ((ch & 0x80) == 0x80);
> -       return 1;
> -}
> -
> -static unsigned char
> -asn1_id_decode(struct asn1_ctx *ctx,
> -              unsigned int *cls, unsigned int *con, unsigned int *tag)
> -{
> -       unsigned char ch;
> -
> -       if (!asn1_octet_decode(ctx, &ch))
> -               return 0;
> -
> -       *cls = (ch & 0xC0) >> 6;
> -       *con = (ch & 0x20) >> 5;
> -       *tag = (ch & 0x1F);
> -
> -       if (*tag == 0x1F) {
> -               if (!asn1_tag_decode(ctx, tag))
> -                       return 0;
> -       }
> -       return 1;
> -}
> -
> -static unsigned char
> -asn1_length_decode(struct asn1_ctx *ctx, unsigned int *def, unsigned int *len)
> -{
> -       unsigned char ch, cnt;
> -
> -       if (!asn1_octet_decode(ctx, &ch))
> -               return 0;
> -
> -       if (ch == 0x80)
> -               *def = 0;
> -       else {
> -               *def = 1;
> -
> -               if (ch < 0x80)
> -                       *len = ch;
> -               else {
> -                       cnt = (unsigned char) (ch & 0x7F);
> -                       *len = 0;
> -
> -                       while (cnt > 0) {
> -                               if (!asn1_octet_decode(ctx, &ch))
> -                                       return 0;
> -                               *len <<= 8;
> -                               *len |= ch;
> -                               cnt--;
> -                       }
> -               }
> -       }
> -
> -       /* don't trust len bigger than ctx buffer */
> -       if (*len > ctx->end - ctx->pointer)
> -               return 0;
> -
> -       return 1;
> -}
> -
> -static unsigned char
> -asn1_header_decode(struct asn1_ctx *ctx,
> -                  unsigned char **eoc,
> -                  unsigned int *cls, unsigned int *con, unsigned int *tag)
> -{
> -       unsigned int def = 0;
> -       unsigned int len = 0;
> -
> -       if (!asn1_id_decode(ctx, cls, con, tag))
> -               return 0;
> -
> -       if (!asn1_length_decode(ctx, &def, &len))
> -               return 0;
> -
> -       /* primitive shall be definite, indefinite shall be constructed */
> -       if (*con == ASN1_PRI && !def)
> -               return 0;
> -
> -       if (def)
> -               *eoc = ctx->pointer + len;
> -       else
> -               *eoc = NULL;
> -       return 1;
> -}
> -
> -static unsigned char
> -asn1_eoc_decode(struct asn1_ctx *ctx, unsigned char *eoc)
> +int
> +decode_negTokenInit(unsigned char *security_blob, int length,
> +                   struct TCP_Server_Info *server)
>  {
> -       unsigned char ch;
> -
> -       if (eoc == NULL) {
> -               if (!asn1_octet_decode(ctx, &ch))
> -                       return 0;
> -
> -               if (ch != 0x00) {
> -                       ctx->error = ASN1_ERR_DEC_EOC_MISMATCH;
> -                       return 0;
> -               }
> -
> -               if (!asn1_octet_decode(ctx, &ch))
> -                       return 0;
> -
> -               if (ch != 0x00) {
> -                       ctx->error = ASN1_ERR_DEC_EOC_MISMATCH;
> -                       return 0;
> -               }
> -               return 1;
> -       } else {
> -               if (ctx->pointer != eoc) {
> -                       ctx->error = ASN1_ERR_DEC_LENGTH_MISMATCH;
> -                       return 0;
> -               }
> +       if (asn1_ber_decoder(&spnego_negtokeninit_decoder, server,
> +                            security_blob, length) == 0)
>                 return 1;
> -       }
> -}
> -
> -/* static unsigned char asn1_null_decode(struct asn1_ctx *ctx,
> -                                     unsigned char *eoc)
> -{
> -       ctx->pointer = eoc;
> -       return 1;
> -}
> -
> -static unsigned char asn1_long_decode(struct asn1_ctx *ctx,
> -                                     unsigned char *eoc, long *integer)
> -{
> -       unsigned char ch;
> -       unsigned int len;
> -
> -       if (!asn1_octet_decode(ctx, &ch))
> -               return 0;
> -
> -       *integer = (signed char) ch;
> -       len = 1;
> -
> -       while (ctx->pointer < eoc) {
> -               if (++len > sizeof(long)) {
> -                       ctx->error = ASN1_ERR_DEC_BADVALUE;
> -                       return 0;
> -               }
> -
> -               if (!asn1_octet_decode(ctx, &ch))
> -                       return 0;
> -
> -               *integer <<= 8;
> -               *integer |= ch;
> -       }
> -       return 1;
> -}
> -
> -static unsigned char asn1_uint_decode(struct asn1_ctx *ctx,
> -                                     unsigned char *eoc,
> -                                     unsigned int *integer)
> -{
> -       unsigned char ch;
> -       unsigned int len;
> -
> -       if (!asn1_octet_decode(ctx, &ch))
> -               return 0;
> -
> -       *integer = ch;
> -       if (ch == 0)
> -               len = 0;
>         else
> -               len = 1;
> -
> -       while (ctx->pointer < eoc) {
> -               if (++len > sizeof(unsigned int)) {
> -                       ctx->error = ASN1_ERR_DEC_BADVALUE;
> -                       return 0;
> -               }
> -
> -               if (!asn1_octet_decode(ctx, &ch))
> -                       return 0;
> -
> -               *integer <<= 8;
> -               *integer |= ch;
> -       }
> -       return 1;
> -}
> -
> -static unsigned char asn1_ulong_decode(struct asn1_ctx *ctx,
> -                                      unsigned char *eoc,
> -                                      unsigned long *integer)
> -{
> -       unsigned char ch;
> -       unsigned int len;
> -
> -       if (!asn1_octet_decode(ctx, &ch))
>                 return 0;
> -
> -       *integer = ch;
> -       if (ch == 0)
> -               len = 0;
> -       else
> -               len = 1;
> -
> -       while (ctx->pointer < eoc) {
> -               if (++len > sizeof(unsigned long)) {
> -                       ctx->error = ASN1_ERR_DEC_BADVALUE;
> -                       return 0;
> -               }
> -
> -               if (!asn1_octet_decode(ctx, &ch))
> -                       return 0;
> -
> -               *integer <<= 8;
> -               *integer |= ch;
> -       }
> -       return 1;
>  }
>
> -static unsigned char
> -asn1_octets_decode(struct asn1_ctx *ctx,
> -                  unsigned char *eoc,
> -                  unsigned char **octets, unsigned int *len)
> +int gssapi_this_mech(void *context, size_t hdrlen,
> +                    unsigned char tag, const void *value, size_t vlen)
>  {
> -       unsigned char *ptr;
> -
> -       *len = 0;
> -
> -       *octets = kmalloc(eoc - ctx->pointer, GFP_ATOMIC);
> -       if (*octets == NULL) {
> -               return 0;
> -       }
> -
> -       ptr = *octets;
> -       while (ctx->pointer < eoc) {
> -               if (!asn1_octet_decode(ctx, (unsigned char *) ptr++)) {
> -                       kfree(*octets);
> -                       *octets = NULL;
> -                       return 0;
> -               }
> -               (*len)++;
> -       }
> -       return 1;
> -} */
> -
> -static unsigned char
> -asn1_subid_decode(struct asn1_ctx *ctx, unsigned long *subid)
> -{
> -       unsigned char ch;
> -
> -       *subid = 0;
> -
> -       do {
> -               if (!asn1_octet_decode(ctx, &ch))
> -                       return 0;
> -
> -               *subid <<= 7;
> -               *subid |= ch & 0x7F;
> -       } while ((ch & 0x80) == 0x80);
> -       return 1;
> -}
> -
> -static int
> -asn1_oid_decode(struct asn1_ctx *ctx,
> -               unsigned char *eoc, unsigned long **oid, unsigned int *len)
> -{
> -       unsigned long subid;
> -       unsigned int size;
> -       unsigned long *optr;
> -
> -       size = eoc - ctx->pointer + 1;
> -
> -       /* first subid actually encodes first two subids */
> -       if (size < 2 || size > UINT_MAX/sizeof(unsigned long))
> -               return 0;
> -
> -       *oid = kmalloc_array(size, sizeof(unsigned long), GFP_ATOMIC);
> -       if (*oid == NULL)
> -               return 0;
> -
> -       optr = *oid;
> -
> -       if (!asn1_subid_decode(ctx, &subid)) {
> -               kfree(*oid);
> -               *oid = NULL;
> -               return 0;
> -       }
> -
> -       if (subid < 40) {
> -               optr[0] = 0;
> -               optr[1] = subid;
> -       } else if (subid < 80) {
> -               optr[0] = 1;
> -               optr[1] = subid - 40;
> -       } else {
> -               optr[0] = 2;
> -               optr[1] = subid - 80;
> -       }
> -
> -       *len = 2;
> -       optr += 2;
> +       enum OID oid;
>
> -       while (ctx->pointer < eoc) {
> -               if (++(*len) > size) {
> -                       ctx->error = ASN1_ERR_DEC_BADVALUE;
> -                       kfree(*oid);
> -                       *oid = NULL;
> -                       return 0;
> -               }
> +       oid = look_up_OID(value, vlen);
> +       if (oid != OID_spnego) {
> +               char buf[50];
>
> -               if (!asn1_subid_decode(ctx, optr++)) {
> -                       kfree(*oid);
> -                       *oid = NULL;
> -                       return 0;
> -               }
> +               sprint_oid(value, vlen, buf, sizeof(buf));
> +               cifs_dbg(FYI, "Error decoding negTokenInit header: unexpected OID %s\n",
> +                        buf);
> +               return -EBADMSG;
>         }
> -       return 1;
> +       return 0;
>  }
>
> -static int
> -compare_oid(unsigned long *oid1, unsigned int oid1len,
> -           unsigned long *oid2, unsigned int oid2len)
> +int neg_token_init_mech_type(void *context, size_t hdrlen,
> +                            unsigned char tag,
> +                            const void *value, size_t vlen)
>  {
> -       unsigned int i;
> +       struct TCP_Server_Info *server = context;
> +       enum OID oid;
>
> -       if (oid1len != oid2len)
> -               return 0;
> +       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 {
> -               for (i = 0; i < oid1len; i++) {
> -                       if (oid1[i] != oid2[i])
> -                               return 0;
> -               }
> -               return 1;
> -       }
> -}
> -
> -       /* BB check for endian conversion issues here */
> -
> -int
> -decode_negTokenInit(unsigned char *security_blob, int length,
> -                   struct TCP_Server_Info *server)
> -{
> -       struct asn1_ctx ctx;
> -       unsigned char *end;
> -       unsigned char *sequence_end;
> -       unsigned long *oid = NULL;
> -       unsigned int cls, con, tag, oidlen, rc;
> -
> -       /* cifs_dump_mem(" Received SecBlob ", security_blob, length); */
> -
> -       asn1_open(&ctx, security_blob, length);
> +               char buf[50];
>
> -       /* GSSAPI header */
> -       if (asn1_header_decode(&ctx, &end, &cls, &con, &tag) == 0) {
> -               cifs_dbg(FYI, "Error decoding negTokenInit header\n");
> -               return 0;
> -       } else if ((cls != ASN1_APL) || (con != ASN1_CON)
> -                  || (tag != ASN1_EOC)) {
> -               cifs_dbg(FYI, "cls = %d con = %d tag = %d\n", cls, con, tag);
> -               return 0;
> +               sprint_oid(value, vlen, buf, sizeof(buf));
> +               cifs_dbg(FYI, "Decoding negTokenInit: unsupported OID %s\n",
> +                        buf);
>         }
> -
> -       /* Check for SPNEGO OID -- remember to free obj->oid */
> -       rc = asn1_header_decode(&ctx, &end, &cls, &con, &tag);
> -       if (rc) {
> -               if ((tag == ASN1_OJI) && (con == ASN1_PRI) &&
> -                   (cls == ASN1_UNI)) {
> -                       rc = asn1_oid_decode(&ctx, end, &oid, &oidlen);
> -                       if (rc) {
> -                               rc = compare_oid(oid, oidlen, SPNEGO_OID,
> -                                                SPNEGO_OID_LEN);
> -                               kfree(oid);
> -                       }
> -               } else
> -                       rc = 0;
> -       }
> -
> -       /* SPNEGO OID not present or garbled -- bail out */
> -       if (!rc) {
> -               cifs_dbg(FYI, "Error decoding negTokenInit header\n");
> -               return 0;
> -       }
> -
> -       /* SPNEGO */
> -       if (asn1_header_decode(&ctx, &end, &cls, &con, &tag) == 0) {
> -               cifs_dbg(FYI, "Error decoding negTokenInit\n");
> -               return 0;
> -       } else if ((cls != ASN1_CTX) || (con != ASN1_CON)
> -                  || (tag != ASN1_EOC)) {
> -               cifs_dbg(FYI, "cls = %d con = %d tag = %d end = %p exit 0\n",
> -                        cls, con, tag, end);
> -               return 0;
> -       }
> -
> -       /* negTokenInit */
> -       if (asn1_header_decode(&ctx, &end, &cls, &con, &tag) == 0) {
> -               cifs_dbg(FYI, "Error decoding negTokenInit\n");
> -               return 0;
> -       } else if ((cls != ASN1_UNI) || (con != ASN1_CON)
> -                  || (tag != ASN1_SEQ)) {
> -               cifs_dbg(FYI, "cls = %d con = %d tag = %d end = %p exit 1\n",
> -                        cls, con, tag, end);
> -               return 0;
> -       }
> -
> -       /* sequence */
> -       if (asn1_header_decode(&ctx, &end, &cls, &con, &tag) == 0) {
> -               cifs_dbg(FYI, "Error decoding 2nd part of negTokenInit\n");
> -               return 0;
> -       } else if ((cls != ASN1_CTX) || (con != ASN1_CON)
> -                  || (tag != ASN1_EOC)) {
> -               cifs_dbg(FYI, "cls = %d con = %d tag = %d end = %p exit 0\n",
> -                        cls, con, tag, end);
> -               return 0;
> -       }
> -
> -       /* sequence of */
> -       if (asn1_header_decode
> -           (&ctx, &sequence_end, &cls, &con, &tag) == 0) {
> -               cifs_dbg(FYI, "Error decoding 2nd part of negTokenInit\n");
> -               return 0;
> -       } else if ((cls != ASN1_UNI) || (con != ASN1_CON)
> -                  || (tag != ASN1_SEQ)) {
> -               cifs_dbg(FYI, "cls = %d con = %d tag = %d sequence_end = %p exit 1\n",
> -                        cls, con, tag, sequence_end);
> -               return 0;
> -       }
> -
> -       /* list of security mechanisms */
> -       while (!asn1_eoc_decode(&ctx, sequence_end)) {
> -               rc = asn1_header_decode(&ctx, &end, &cls, &con, &tag);
> -               if (!rc) {
> -                       cifs_dbg(FYI, "Error decoding negTokenInit hdr exit2\n");
> -                       return 0;
> -               }
> -               if ((tag == ASN1_OJI) && (con == ASN1_PRI)) {
> -                       if (asn1_oid_decode(&ctx, end, &oid, &oidlen)) {
> -
> -                               cifs_dbg(FYI, "OID len = %d oid = 0x%lx 0x%lx 0x%lx 0x%lx\n",
> -                                        oidlen, *oid, *(oid + 1), *(oid + 2),
> -                                        *(oid + 3));
> -
> -                               if (compare_oid(oid, oidlen, MSKRB5_OID,
> -                                               MSKRB5_OID_LEN))
> -                                       server->sec_mskerberos = true;
> -                               else if (compare_oid(oid, oidlen, KRB5U2U_OID,
> -                                                    KRB5U2U_OID_LEN))
> -                                       server->sec_kerberosu2u = true;
> -                               else if (compare_oid(oid, oidlen, KRB5_OID,
> -                                                    KRB5_OID_LEN))
> -                                       server->sec_kerberos = true;
> -                               else if (compare_oid(oid, oidlen, NTLMSSP_OID,
> -                                                    NTLMSSP_OID_LEN))
> -                                       server->sec_ntlmssp = true;
> -
> -                               kfree(oid);
> -                       }
> -               } else {
> -                       cifs_dbg(FYI, "Should be an oid what is going on?\n");
> -               }
> -       }
> -
> -       /*
> -        * We currently ignore anything at the end of the SPNEGO blob after
> -        * the mechTypes have been parsed, since none of that info is
> -        * used at the moment.
> -        */
> -       return 1;
> +       return 0;
>  }
> diff --git a/fs/cifs/spnego_negtokeninit.asn1 b/fs/cifs/spnego_negtokeninit.asn1
> new file mode 100644
> index 000000000000..aa5b4a61b3f5
> --- /dev/null
> +++ b/fs/cifs/spnego_negtokeninit.asn1
> @@ -0,0 +1,40 @@
> +GSSAPI ::=
> +       [APPLICATION 0] IMPLICIT SEQUENCE {
> +               thisMech
> +                       OBJECT IDENTIFIER ({gssapi_this_mech}),
> +               negotiationToken
> +                       NegotiationToken
> +       }
> +
> +MechType ::= OBJECT IDENTIFIER ({neg_token_init_mech_type})
> +
> +MechTypeList ::= SEQUENCE OF MechType
> +
> +NegHints ::= SEQUENCE {
> +       hintName
> +               [0] GeneralString OPTIONAL,
> +       hintAddress
> +               [1] OCTET STRING OPTIONAL
> +       }
> +
> +NegTokenInit2 ::=
> +       SEQUENCE {
> +               mechTypes
> +                       [0] MechTypeList OPTIONAL,
> +               reqFlags
> +                       [1] BIT STRING OPTIONAL,
> +               mechToken
> +                       [2] OCTET STRING OPTIONAL,
> +               negHints
> +                       [3] NegHints OPTIONAL,
> +               mechListMIC
> +                       [3] OCTET STRING OPTIONAL
> +       }
> +
> +NegotiationToken ::=
> +       CHOICE {
> +               negTokenInit
> +                       [0] NegTokenInit2,
> +               negTokenTarg
> +                       [1] ANY
> +       }
> diff --git a/include/linux/oid_registry.h b/include/linux/oid_registry.h
> index 461b7aa587ba..3d8db1f6a5db 100644
> --- a/include/linux/oid_registry.h
> +++ b/include/linux/oid_registry.h
> @@ -54,6 +54,10 @@ enum OID {
>         OID_md4,                        /* 1.2.840.113549.2.4 */
>         OID_md5,                        /* 1.2.840.113549.2.5 */
>
> +       OID_mskrb5,                     /* 1.2.840.48018.1.2.2 */
> +       OID_krb5,                       /* 1.2.840.113554.1.2.2 */
> +       OID_krb5u2u,                    /* 1.2.840.113554.1.2.2.3 */
> +
>         /* Microsoft Authenticode & Software Publishing */
>         OID_msIndirectData,             /* 1.3.6.1.4.1.311.2.1.4 */
>         OID_msStatementType,            /* 1.3.6.1.4.1.311.2.1.11 */
> @@ -62,6 +66,10 @@ enum OID {
>         OID_msIndividualSPKeyPurpose,   /* 1.3.6.1.4.1.311.2.1.21 */
>         OID_msOutlookExpress,           /* 1.3.6.1.4.1.311.16.4 */
>
> +       OID_ntlmssp,                    /* 1.3.6.1.4.1.311.2.2.10 */
> +
> +       OID_spnego,                     /* 1.3.6.1.5.5.2 */
> +
>         OID_certAuthInfoAccess,         /* 1.3.6.1.5.5.7.1.1 */
>         OID_sha1,                       /* 1.3.14.3.2.26 */
>         OID_id_ansip384r1,              /* 1.3.132.0.34 */
> --
> 2.25.1
>


-- 
Thanks,

Steve



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