Initial import

1 files changed, 623 insertions, 0 deletions

diff --git a/fs/cifs/asn1.c b/fs/cifs/asn1.c
new file mode 100644
index 000000000..a3b56544c
--- /dev/null
+++ b/fs/cifs/asn1.c
@@ -0,0 +1,623 @@
+/*
+ * 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;
+}