cifsd: decoding gss token using lib/asn1_decoder.c
Decode gss token of SMB2_SESSSION_SETUP using
lib/asn1_decoder.c
Signed-off-by: Hyunchul Lee <hyc.lee@gmail.com>
Signed-off-by: Namjae Jeon <namjae.jeon@samsung.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
diff --git a/fs/cifsd/asn1.c b/fs/cifsd/asn1.c
index aa702b6..aa6ea85 100644
--- a/fs/cifsd/asn1.c
+++ b/fs/cifsd/asn1.c
@@ -11,61 +11,15 @@
#include <linux/kernel.h>
#include <linux/mm.h>
#include <linux/slab.h>
+#include <linux/oid_registry.h>
#include "glob.h"
#include "asn1.h"
#include "connection.h"
#include "auth.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
+#include "spnego_negtokeninit.asn1.h"
+#include "spnego_negtokentarg.asn1.h"
#define SPNEGO_OID_LEN 7
#define NTLMSSP_OID_LEN 10
@@ -81,212 +35,49 @@ static unsigned long MSKRB5_OID[7] = { 1, 2, 840, 48018, 1, 2, 2 };
static char NTLMSSP_OID_STR[NTLMSSP_OID_LEN] = { 0x2b, 0x06, 0x01, 0x04, 0x01,
0x82, 0x37, 0x02, 0x02, 0x0a };
-/*
- * 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)
+static bool
+asn1_subid_decode(const unsigned char **begin, const unsigned char *end,
+ unsigned long *subid)
{
- 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--;
- }
- }
- }
-
- /* 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) {
- 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;
- }
- } else {
- if (ctx->pointer != eoc) {
- ctx->error = ASN1_ERR_DEC_LENGTH_MISMATCH;
- return 0;
- }
- }
- return 1;
-}
-
-static unsigned char
-asn1_subid_decode(struct asn1_ctx *ctx, unsigned long *subid)
-{
+ const unsigned char *ptr = *begin;
unsigned char ch;
*subid = 0;
do {
- if (!asn1_octet_decode(ctx, &ch))
- return 0;
+ if (ptr >= end)
+ return false;
+ ch = *ptr++;
*subid <<= 7;
*subid |= ch & 0x7F;
} while ((ch & 0x80) == 0x80);
- return 1;
+
+ *begin = ptr;
+ return true;
}
-static int
-asn1_oid_decode(struct asn1_ctx *ctx,
- unsigned char *eoc, unsigned long **oid, unsigned int *len)
+static bool asn1_oid_decode(const unsigned char *value, size_t vlen,
+ unsigned long **oid, size_t *oidlen)
{
- unsigned long subid;
- unsigned int size;
+ const unsigned char *iptr = value, *end = value + vlen;
unsigned long *optr;
+ unsigned long subid;
- size = eoc - ctx->pointer + 1;
+ vlen += 1;
+ if (vlen < 2 || vlen > UINT_MAX/sizeof(unsigned long))
+ return false;
- /* 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_KERNEL);
+ *oid = kmalloc(vlen * sizeof(unsigned long), GFP_KERNEL);
if (!*oid)
- return 0;
+ return false;
optr = *oid;
- if (!asn1_subid_decode(ctx, &subid)) {
+ if (!asn1_subid_decode(&iptr, end, &subid)) {
kfree(*oid);
*oid = NULL;
- return 0;
+ return false;
}
if (subid < 40) {
@@ -300,285 +91,55 @@ asn1_oid_decode(struct asn1_ctx *ctx,
optr[1] = subid - 80;
}
- *len = 2;
+ *oidlen = 2;
optr += 2;
- while (ctx->pointer < eoc) {
- if (++(*len) > size) {
- ctx->error = ASN1_ERR_DEC_BADVALUE;
+ while (iptr < end) {
+ if (++(*oidlen) > vlen) {
kfree(*oid);
*oid = NULL;
- return 0;
+ return false;
}
- if (!asn1_subid_decode(ctx, optr++)) {
+ if (!asn1_subid_decode(&iptr, end, optr++)) {
kfree(*oid);
*oid = NULL;
- return 0;
+ return false;
}
}
- return 1;
+ return true;
}
-static int
-compare_oid(unsigned long *oid1, unsigned int oid1len,
- unsigned long *oid2, unsigned int oid2len)
+static bool
+oid_eq(unsigned long *oid1, unsigned int oid1len,
+ unsigned long *oid2, unsigned int oid2len)
{
unsigned int i;
if (oid1len != oid2len)
- return 0;
+ return false;
for (i = 0; i < oid1len; i++) {
if (oid1[i] != oid2[i])
- return 0;
+ return false;
}
- return 1;
+ return true;
}
-/* BB check for endian conversion issues here */
-
int
ksmbd_decode_negTokenInit(unsigned char *security_blob, int length,
- struct ksmbd_conn *conn)
+ struct ksmbd_conn *conn)
{
- struct asn1_ctx ctx;
- unsigned char *end;
- unsigned char *sequence_end;
- unsigned long *oid = NULL;
- unsigned int cls, con, tag, oidlen, rc, mechTokenlen;
- unsigned int mech_type;
-
- ksmbd_debug(AUTH, "Received SecBlob: length %d\n", length);
-
- asn1_open(&ctx, security_blob, length);
-
- /* GSSAPI header */
- if (asn1_header_decode(&ctx, &end, &cls, &con, &tag) == 0) {
- ksmbd_debug(AUTH, "Error decoding negTokenInit header\n");
- return 0;
- } else if ((cls != ASN1_APL) || (con != ASN1_CON)
- || (tag != ASN1_EOC)) {
- ksmbd_debug(AUTH, "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) {
- ksmbd_debug(AUTH, "Error decoding negTokenInit header\n");
- return 0;
- }
-
- /* SPNEGO */
- if (asn1_header_decode(&ctx, &end, &cls, &con, &tag) == 0) {
- ksmbd_debug(AUTH, "Error decoding negTokenInit\n");
- return 0;
- } else if ((cls != ASN1_CTX) || (con != ASN1_CON)
- || (tag != ASN1_EOC)) {
- ksmbd_debug(AUTH,
- "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) {
- ksmbd_debug(AUTH, "Error decoding negTokenInit\n");
- return 0;
- } else if ((cls != ASN1_UNI) || (con != ASN1_CON)
- || (tag != ASN1_SEQ)) {
- ksmbd_debug(AUTH,
- "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) {
- ksmbd_debug(AUTH, "Error decoding 2nd part of negTokenInit\n");
- return 0;
- } else if ((cls != ASN1_CTX) || (con != ASN1_CON)
- || (tag != ASN1_EOC)) {
- ksmbd_debug(AUTH,
- "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) {
- ksmbd_debug(AUTH, "Error decoding 2nd part of negTokenInit\n");
- return 0;
- } else if ((cls != ASN1_UNI) || (con != ASN1_CON)
- || (tag != ASN1_SEQ)) {
- ksmbd_debug(AUTH,
- "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) {
- ksmbd_debug(AUTH,
- "Error decoding negTokenInit hdr exit2\n");
- return 0;
- }
- if ((tag == ASN1_OJI) && (con == ASN1_PRI)) {
- if (asn1_oid_decode(&ctx, end, &oid, &oidlen)) {
- if (compare_oid(oid, oidlen, MSKRB5_OID,
- MSKRB5_OID_LEN))
- mech_type = KSMBD_AUTH_MSKRB5;
- else if (compare_oid(oid, oidlen, KRB5U2U_OID,
- KRB5U2U_OID_LEN))
- mech_type = KSMBD_AUTH_KRB5U2U;
- else if (compare_oid(oid, oidlen, KRB5_OID,
- KRB5_OID_LEN))
- mech_type = KSMBD_AUTH_KRB5;
- else if (compare_oid(oid, oidlen, NTLMSSP_OID,
- NTLMSSP_OID_LEN))
- mech_type = KSMBD_AUTH_NTLMSSP;
- else {
- kfree(oid);
- continue;
- }
-
- conn->auth_mechs |= mech_type;
- if (conn->preferred_auth_mech == 0)
- conn->preferred_auth_mech = mech_type;
- kfree(oid);
- }
- } else {
- ksmbd_debug(AUTH,
- "Should be an oid what is going on?\n");
- }
- }
-
- /* sequence */
- if (asn1_header_decode(&ctx, &end, &cls, &con, &tag) == 0) {
- ksmbd_debug(AUTH, "Error decoding 2nd part of negTokenInit\n");
- return 0;
- } else if ((cls != ASN1_CTX) || (con != ASN1_CON)
- || (tag != ASN1_INT)) {
- ksmbd_debug(AUTH,
- "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, &end, &cls, &con, &tag) == 0) {
- ksmbd_debug(AUTH, "Error decoding 2nd part of negTokenInit\n");
- return 0;
- } else if ((cls != ASN1_UNI) || (con != ASN1_PRI)
- || (tag != ASN1_OTS)) {
- ksmbd_debug(AUTH,
- "cls = %d con = %d tag = %d end = %p (%d) exit 0\n",
- cls, con, tag, end, *end);
- return 0;
- }
-
- mechTokenlen = ctx.end - ctx.pointer;
- conn->mechToken = kmalloc(mechTokenlen + 1, GFP_KERNEL);
- if (!conn->mechToken) {
- ksmbd_err("memory allocation error\n");
- return 0;
- }
-
- memcpy(conn->mechToken, ctx.pointer, mechTokenlen);
- conn->mechToken[mechTokenlen] = '\0';
-
- return 1;
+ return asn1_ber_decoder(&spnego_negtokeninit_decoder, conn,
+ security_blob, length);
}
int
ksmbd_decode_negTokenTarg(unsigned char *security_blob, int length,
- struct ksmbd_conn *conn)
+ struct ksmbd_conn *conn)
{
- struct asn1_ctx ctx;
- unsigned char *end;
- unsigned int cls, con, tag, mechTokenlen;
-
- ksmbd_debug(AUTH, "Received Auth SecBlob: length %d\n", length);
-
- asn1_open(&ctx, security_blob, length);
-
- /* GSSAPI header */
- if (asn1_header_decode(&ctx, &end, &cls, &con, &tag) == 0) {
- ksmbd_debug(AUTH, "Error decoding negTokenInit header\n");
- return 0;
- } else if ((cls != ASN1_CTX) || (con != ASN1_CON)
- || (tag != ASN1_BOL)) {
- ksmbd_debug(AUTH, "cls = %d con = %d tag = %d\n", cls, con,
- tag);
- return 0;
- }
-
- /* SPNEGO */
- if (asn1_header_decode(&ctx, &end, &cls, &con, &tag) == 0) {
- ksmbd_debug(AUTH, "Error decoding negTokenInit\n");
- return 0;
- } else if ((cls != ASN1_UNI) || (con != ASN1_CON)
- || (tag != ASN1_SEQ)) {
- ksmbd_debug(AUTH,
- "cls = %d con = %d tag = %d end = %p (%d) exit 0\n",
- cls, con, tag, end, *end);
- return 0;
- }
-
- /* negTokenTarg */
- if (asn1_header_decode(&ctx, &end, &cls, &con, &tag) == 0) {
- ksmbd_debug(AUTH, "Error decoding negTokenInit\n");
- return 0;
- } else if ((cls != ASN1_CTX) || (con != ASN1_CON)
- || (tag != ASN1_INT)) {
- ksmbd_debug(AUTH,
- "cls = %d con = %d tag = %d end = %p (%d) exit 1\n",
- cls, con, tag, end, *end);
- return 0;
- }
-
- /* negTokenTarg */
- if (asn1_header_decode(&ctx, &end, &cls, &con, &tag) == 0) {
- ksmbd_debug(AUTH, "Error decoding negTokenInit\n");
- return 0;
- } else if ((cls != ASN1_UNI) || (con != ASN1_PRI)
- || (tag != ASN1_OTS)) {
- ksmbd_debug(AUTH,
- "cls = %d con = %d tag = %d end = %p (%d) exit 1\n",
- cls, con, tag, end, *end);
- return 0;
- }
-
- mechTokenlen = ctx.end - ctx.pointer;
- conn->mechToken = kmalloc(mechTokenlen + 1, GFP_KERNEL);
- if (!conn->mechToken) {
- ksmbd_err("memory allocation error\n");
- return 0;
- }
-
- memcpy(conn->mechToken, ctx.pointer, mechTokenlen);
- conn->mechToken[mechTokenlen] = '\0';
-
- return 1;
+ return asn1_ber_decoder(&spnego_negtokentarg_decoder, conn,
+ security_blob, length);
}
static int compute_asn_hdr_len_bytes(int len)
@@ -700,3 +261,92 @@ int build_spnego_ntlmssp_auth_blob(unsigned char **pbuffer, u16 *buflen,
*buflen = total_len;
return 0;
}
+
+int gssapi_this_mech(void *context, size_t hdrlen,
+ unsigned char tag, const void *value, size_t vlen)
+{
+ unsigned long *oid;
+ size_t oidlen;
+ int err = 0;
+
+ if (!asn1_oid_decode(value, vlen, &oid, &oidlen)) {
+ err = -EBADMSG;
+ goto out;
+ }
+
+ if (!oid_eq(oid, oidlen, SPNEGO_OID, SPNEGO_OID_LEN))
+ err = -EBADMSG;
+ kfree(oid);
+out:
+ if (err) {
+ char buf[50];
+
+ sprint_oid(value, vlen, buf, sizeof(buf));
+ ksmbd_debug(AUTH, "Unexpected OID: %s\n", buf);
+ }
+ return err;
+}
+
+int neg_token_init_mech_type(void *context, size_t hdrlen,
+ unsigned char tag, const void *value, size_t vlen)
+{
+ struct ksmbd_conn *conn = context;
+ unsigned long *oid;
+ size_t oidlen;
+ int mech_type;
+
+ if (!asn1_oid_decode(value, vlen, &oid, &oidlen)) {
+ char buf[50];
+
+ sprint_oid(value, vlen, buf, sizeof(buf));
+ ksmbd_debug(AUTH, "Unexpected OID: %s\n", buf);
+ return -EBADMSG;
+ }
+
+ if (oid_eq(oid, oidlen, NTLMSSP_OID, NTLMSSP_OID_LEN))
+ mech_type = KSMBD_AUTH_NTLMSSP;
+ else if (oid_eq(oid, oidlen, MSKRB5_OID, MSKRB5_OID_LEN))
+ mech_type = KSMBD_AUTH_MSKRB5;
+ else if (oid_eq(oid, oidlen, KRB5_OID, KRB5_OID_LEN))
+ mech_type = KSMBD_AUTH_KRB5;
+ else if (oid_eq(oid, oidlen, KRB5U2U_OID, KRB5U2U_OID_LEN))
+ mech_type = KSMBD_AUTH_KRB5U2U;
+ else
+ goto out;
+
+ conn->auth_mechs |= mech_type;
+ if (conn->preferred_auth_mech == 0)
+ conn->preferred_auth_mech = mech_type;
+
+out:
+ kfree(oid);
+ return 0;
+}
+
+int neg_token_init_mech_token(void *context, size_t hdrlen,
+ unsigned char tag, const void *value, size_t vlen)
+{
+ struct ksmbd_conn *conn = context;
+
+ conn->mechToken = kmalloc(vlen + 1, GFP_KERNEL);
+ if (!conn->mechToken)
+ return -ENOMEM;
+
+ memcpy(conn->mechToken, value, vlen);
+ conn->mechToken[vlen] = '\0';
+ return 0;
+}
+
+int neg_token_targ_resp_token(void *context, size_t hdrlen,
+ unsigned char tag, const void *value, size_t vlen)
+{
+ struct ksmbd_conn *conn = context;
+
+ conn->mechToken = kmalloc(vlen + 1, GFP_KERNEL);
+ if (!conn->mechToken)
+ return -ENOMEM;
+
+ memcpy(conn->mechToken, value, vlen);
+ conn->mechToken[vlen] = '\0';
+ return 0;
+}