624 lines
14 KiB
C
624 lines
14 KiB
C
/*
|
|
* 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).
|
|
*
|
|
* This program is free software; you can redistribute it and/or modify
|
|
* it under the terms of the GNU General Public License as published by
|
|
* the Free Software Foundation; either version 2 of the License, or
|
|
* (at your option) any later version.
|
|
* This program is distributed in the hope that it will be useful,
|
|
* but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
|
* GNU General Public License for more details.
|
|
* You should have received a copy of the GNU General Public License
|
|
* along with this program; if not, write to the Free Software
|
|
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
|
|
*/
|
|
|
|
#include <linux/module.h>
|
|
#include <linux/types.h>
|
|
#include <linux/kernel.h>
|
|
#include <linux/mm.h>
|
|
#include <linux/slab.h>
|
|
#include "cifspdu.h"
|
|
#include "cifsglob.h"
|
|
#include "cifs_debug.h"
|
|
#include "cifsproto.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)
|
|
{
|
|
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;
|
|
}
|
|
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)
|
|
{
|
|
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(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;
|
|
|
|
while (ctx->pointer < eoc) {
|
|
if (++(*len) > size) {
|
|
ctx->error = ASN1_ERR_DEC_BADVALUE;
|
|
kfree(*oid);
|
|
*oid = NULL;
|
|
return 0;
|
|
}
|
|
|
|
if (!asn1_subid_decode(ctx, optr++)) {
|
|
kfree(*oid);
|
|
*oid = NULL;
|
|
return 0;
|
|
}
|
|
}
|
|
return 1;
|
|
}
|
|
|
|
static int
|
|
compare_oid(unsigned long *oid1, unsigned int oid1len,
|
|
unsigned long *oid2, unsigned int oid2len)
|
|
{
|
|
unsigned int i;
|
|
|
|
if (oid1len != oid2len)
|
|
return 0;
|
|
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);
|
|
|
|
/* 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;
|
|
}
|
|
|
|
/* 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 (%d) exit 0\n",
|
|
cls, con, tag, end, *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 (%d) exit 1\n",
|
|
cls, con, tag, end, *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 (%d) exit 0\n",
|
|
cls, con, tag, end, *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 end = %p (%d) exit 1\n",
|
|
cls, con, tag, end, *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;
|
|
}
|