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-rw-r--r--fs/cifs/asn1.c618
1 files changed, 618 insertions, 0 deletions
diff --git a/fs/cifs/asn1.c b/fs/cifs/asn1.c
new file mode 100644
index 000000000000..e02010dd73ec
--- /dev/null
+++ b/fs/cifs/asn1.c
@@ -0,0 +1,618 @@
+/*
+ * 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/config.h>
+#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_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
+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 };
+
+/*
+ * 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;
+}
+
+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--;
+ }
+ }
+ }
+ 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, len;
+
+ if (!asn1_id_decode(ctx, cls, con, tag))
+ return 0;
+
+ if (!asn1_length_decode(ctx, &def, &len))
+ 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;
+ *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,
+ enum securityEnum *secType)
+{
+ struct asn1_ctx ctx;
+ unsigned char *end;
+ unsigned char *sequence_end;
+ unsigned long *oid = NULL;
+ unsigned int cls, con, tag, oidlen, rc;
+ int use_ntlmssp = FALSE;
+
+ *secType = NTLM; /* BB eventually make Kerberos or NLTMSSP the default */
+
+ /* cifs_dump_mem(" Received SecBlob ", security_blob, length); */
+
+ asn1_open(&ctx, security_blob, length);
+
+ if (asn1_header_decode(&ctx, &end, &cls, &con, &tag) == 0) {
+ cFYI(1, ("Error decoding negTokenInit header "));
+ return 0;
+ } else if ((cls != ASN1_APL) || (con != ASN1_CON)
+ || (tag != ASN1_EOC)) {
+ cFYI(1, ("cls = %d con = %d tag = %d", cls, con, tag));
+ return 0;
+ } else {
+ /* remember to free obj->oid */
+ rc = asn1_header_decode(&ctx, &end, &cls, &con, &tag);
+ if (rc) {
+ if ((tag == ASN1_OJI) && (cls == ASN1_PRI)) {
+ 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;
+ }
+
+ if (!rc) {
+ cFYI(1, ("Error decoding negTokenInit header"));
+ return 0;
+ }
+
+ if (asn1_header_decode(&ctx, &end, &cls, &con, &tag) == 0) {
+ cFYI(1, ("Error decoding negTokenInit "));
+ return 0;
+ } else if ((cls != ASN1_CTX) || (con != ASN1_CON)
+ || (tag != ASN1_EOC)) {
+ cFYI(1,("cls = %d con = %d tag = %d end = %p (%d) exit 0",
+ cls, con, tag, end, *end));
+ return 0;
+ }
+
+ if (asn1_header_decode(&ctx, &end, &cls, &con, &tag) == 0) {
+ cFYI(1, ("Error decoding negTokenInit "));
+ return 0;
+ } else if ((cls != ASN1_UNI) || (con != ASN1_CON)
+ || (tag != ASN1_SEQ)) {
+ cFYI(1,("cls = %d con = %d tag = %d end = %p (%d) exit 1",
+ cls, con, tag, end, *end));
+ return 0;
+ }
+
+ if (asn1_header_decode(&ctx, &end, &cls, &con, &tag) == 0) {
+ cFYI(1, ("Error decoding 2nd part of negTokenInit "));
+ return 0;
+ } else if ((cls != ASN1_CTX) || (con != ASN1_CON)
+ || (tag != ASN1_EOC)) {
+ cFYI(1,
+ ("cls = %d con = %d tag = %d end = %p (%d) exit 0",
+ cls, con, tag, end, *end));
+ return 0;
+ }
+
+ if (asn1_header_decode
+ (&ctx, &sequence_end, &cls, &con, &tag) == 0) {
+ cFYI(1, ("Error decoding 2nd part of negTokenInit "));
+ return 0;
+ } else if ((cls != ASN1_UNI) || (con != ASN1_CON)
+ || (tag != ASN1_SEQ)) {
+ cFYI(1,
+ ("cls = %d con = %d tag = %d end = %p (%d) exit 1",
+ cls, con, tag, end, *end));
+ return 0;
+ }
+
+ while (!asn1_eoc_decode(&ctx, sequence_end)) {
+ rc = asn1_header_decode(&ctx, &end, &cls, &con, &tag);
+ if (!rc) {
+ cFYI(1,
+ ("Error 1 decoding negTokenInit header exit 2"));
+ return 0;
+ }
+ if ((tag == ASN1_OJI) && (con == ASN1_PRI)) {
+ rc = asn1_oid_decode(&ctx, end, &oid, &oidlen);
+ if(rc) {
+ cFYI(1,
+ ("OID len = %d oid = 0x%lx 0x%lx 0x%lx 0x%lx",
+ oidlen, *oid, *(oid + 1), *(oid + 2),
+ *(oid + 3)));
+ rc = compare_oid(oid, oidlen, NTLMSSP_OID,
+ NTLMSSP_OID_LEN);
+ if(oid)
+ kfree(oid);
+ if (rc)
+ use_ntlmssp = TRUE;
+ }
+ } else {
+ cFYI(1,("This should be an oid what is going on? "));
+ }
+ }
+
+ if (asn1_header_decode(&ctx, &end, &cls, &con, &tag) == 0) {
+ cFYI(1,
+ ("Error decoding last part of negTokenInit exit 3"));
+ return 0;
+ } else if ((cls != ASN1_CTX) || (con != ASN1_CON)) { /* tag = 3 indicating mechListMIC */
+ cFYI(1,
+ ("Exit 4 cls = %d con = %d tag = %d end = %p (%d)",
+ cls, con, tag, end, *end));
+ return 0;
+ }
+ if (asn1_header_decode(&ctx, &end, &cls, &con, &tag) == 0) {
+ cFYI(1,
+ ("Error decoding last part of negTokenInit exit 5"));
+ return 0;
+ } else if ((cls != ASN1_UNI) || (con != ASN1_CON)
+ || (tag != ASN1_SEQ)) {
+ cFYI(1,
+ ("Exit 6 cls = %d con = %d tag = %d end = %p (%d)",
+ cls, con, tag, end, *end));
+ }
+
+ if (asn1_header_decode(&ctx, &end, &cls, &con, &tag) == 0) {
+ cFYI(1,
+ ("Error decoding last part of negTokenInit exit 7"));
+ return 0;
+ } else if ((cls != ASN1_CTX) || (con != ASN1_CON)) {
+ cFYI(1,
+ ("Exit 8 cls = %d con = %d tag = %d end = %p (%d)",
+ cls, con, tag, end, *end));
+ return 0;
+ }
+ if (asn1_header_decode(&ctx, &end, &cls, &con, &tag) == 0) {
+ cFYI(1,
+ ("Error decoding last part of negTokenInit exit 9"));
+ return 0;
+ } else if ((cls != ASN1_UNI) || (con != ASN1_PRI)
+ || (tag != ASN1_GENSTR)) {
+ cFYI(1,
+ ("Exit 10 cls = %d con = %d tag = %d end = %p (%d)",
+ cls, con, tag, end, *end));
+ return 0;
+ }
+ cFYI(1, ("Need to call asn1_octets_decode() function for this %s", ctx.pointer)); /* is this UTF-8 or ASCII? */
+ }
+
+ /* if (use_kerberos)
+ *secType = Kerberos
+ else */
+ if (use_ntlmssp) {
+ *secType = NTLMSSP;
+ }
+
+ return 1;
+}
generated by cgit v1.2.3 (git 2.0.4) at 2024-11-08 18:38:50 +0000