--- /dev/null
+/*
+ * linux/net/sunrpc/gss_spkm3_token.c
+ *
+ * Copyright (c) 2003 The Regents of the University of Michigan.
+ * All rights reserved.
+ *
+ * Andy Adamson <andros@umich.edu>
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the distribution.
+ * 3. Neither the name of the University nor the names of its
+ * contributors may be used to endorse or promote products derived
+ * from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED
+ * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
+ * BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
+ * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
+ * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+ * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ */
+
+#include <linux/types.h>
+#include <linux/slab.h>
+#include <linux/jiffies.h>
+#include <linux/sunrpc/gss_spkm3.h>
+#include <linux/random.h>
+#include <linux/crypto.h>
+
+#ifdef RPC_DEBUG
+# define RPCDBG_FACILITY RPCDBG_AUTH
+#endif
+
+/*
+ * asn1_bitstring_len()
+ *
+ * calculate the asn1 bitstring length of the xdr_netobject
+ */
+void
+asn1_bitstring_len(struct xdr_netobj *in, int *enclen, int *zerobits)
+{
+ int i, zbit = 0,elen = in->len;
+ char *ptr;
+
+ ptr = &in->data[in->len -1];
+
+ /* count trailing 0's */
+ for(i = in->len; i > 0; i--) {
+ if (*ptr == 0) {
+ ptr--;
+ elen--;
+ } else
+ break;
+ }
+
+ /* count number of 0 bits in final octet */
+ ptr = &in->data[elen - 1];
+ for(i = 0; i < 8; i++) {
+ short mask = 0x01;
+
+ if (!((mask << i) & *ptr))
+ zbit++;
+ else
+ break;
+ }
+ *enclen = elen;
+ *zerobits = zbit;
+}
+
+/*
+ * decode_asn1_bitstring()
+ *
+ * decode a bitstring into a buffer of the expected length.
+ * enclen = bit string length
+ * explen = expected length (define in rfc)
+ */
+int
+decode_asn1_bitstring(struct xdr_netobj *out, char *in, int enclen, int explen)
+{
+ if (!(out->data = kmalloc(explen,GFP_KERNEL)))
+ return 0;
+ out->len = explen;
+ memset(out->data, 0, explen);
+ memcpy(out->data, in, enclen);
+ return 1;
+}
+
+/*
+ * SPKMInnerContextToken choice SPKM_MIC asn1 token layout
+ *
+ * contextid is always 16 bytes plain data. max asn1 bitstring len = 17.
+ *
+ * tokenlen = pos[0] to end of token (max pos[45] with MD5 cksum)
+ *
+ * pos value
+ * ----------
+ * [0] a4 SPKM-MIC tag
+ * [1] ?? innertoken length (max 44)
+ *
+ *
+ * tok_hdr piece of checksum data starts here
+ *
+ * the maximum mic-header len = 9 + 17 = 26
+ * mic-header
+ * ----------
+ * [2] 30 SEQUENCE tag
+ * [3] ?? mic-header length: (max 23) = TokenID + ContextID
+ *
+ * TokenID - all fields constant and can be hardcoded
+ * -------
+ * [4] 02 Type 2
+ * [5] 02 Length 2
+ * [6][7] 01 01 TokenID (SPKM_MIC_TOK)
+ *
+ * ContextID - encoded length not constant, calculated
+ * ---------
+ * [8] 03 Type 3
+ * [9] ?? encoded length
+ * [10] ?? ctxzbit
+ * [11] contextid
+ *
+ * mic_header piece of checksum data ends here.
+ *
+ * int-cksum - encoded length not constant, calculated
+ * ---------
+ * [??] 03 Type 3
+ * [??] ?? encoded length
+ * [??] ?? md5zbit
+ * [??] int-cksum (NID_md5 = 16)
+ *
+ * maximum SPKM-MIC innercontext token length =
+ * 10 + encoded contextid_size(17 max) + 2 + encoded
+ * cksum_size (17 maxfor NID_md5) = 46
+ */
+
+/*
+ * spkm3_mic_header()
+ *
+ * Prepare the SPKM_MIC_TOK mic-header for check-sum calculation
+ * elen: 16 byte context id asn1 bitstring encoded length
+ */
+void
+spkm3_mic_header(unsigned char **hdrbuf, unsigned int *hdrlen, unsigned char *ctxdata, int elen, int zbit)
+{
+ char *hptr = *hdrbuf;
+ char *top = *hdrbuf;
+
+ *(u8 *)hptr++ = 0x30;
+ *(u8 *)hptr++ = elen + 7; /* on the wire header length */
+
+ /* tokenid */
+ *(u8 *)hptr++ = 0x02;
+ *(u8 *)hptr++ = 0x02;
+ *(u8 *)hptr++ = 0x01;
+ *(u8 *)hptr++ = 0x01;
+
+ /* coniextid */
+ *(u8 *)hptr++ = 0x03;
+ *(u8 *)hptr++ = elen + 1; /* add 1 to include zbit */
+ *(u8 *)hptr++ = zbit;
+ memcpy(hptr, ctxdata, elen);
+ hptr += elen;
+ *hdrlen = hptr - top;
+}
+
+/*
+ * spkm3_mic_innercontext_token()
+ *
+ * *tokp points to the beginning of the SPKM_MIC token described
+ * in rfc 2025, section 3.2.1:
+ *
+ */
+void
+spkm3_make_mic_token(unsigned char **tokp, int toklen, struct xdr_netobj *mic_hdr, struct xdr_netobj *md5cksum, int md5elen, int md5zbit)
+{
+ unsigned char *ict = *tokp;
+
+ *(u8 *)ict++ = 0xa4;
+ *(u8 *)ict++ = toklen - 2;
+ memcpy(ict, mic_hdr->data, mic_hdr->len);
+ ict += mic_hdr->len;
+
+ *(u8 *)ict++ = 0x03;
+ *(u8 *)ict++ = md5elen + 1; /* add 1 to include zbit */
+ *(u8 *)ict++ = md5zbit;
+ memcpy(ict, md5cksum->data, md5elen);
+}
+
+u32
+spkm3_verify_mic_token(unsigned char **tokp, int *mic_hdrlen, unsigned char **cksum)
+{
+ struct xdr_netobj spkm3_ctx_id = {.len =0, .data = NULL};
+ unsigned char *ptr = *tokp;
+ int ctxelen;
+ u32 ret = GSS_S_DEFECTIVE_TOKEN;
+
+ /* spkm3 innercontext token preamble */
+ if ((ptr[0] != 0xa4) || (ptr[2] != 0x30)) {
+ dprintk("RPC: BAD SPKM ictoken preamble\n");
+ goto out;
+ }
+
+ *mic_hdrlen = ptr[3];
+
+ /* token type */
+ if ((ptr[4] != 0x02) || (ptr[5] != 0x02)) {
+ dprintk("RPC: BAD asn1 SPKM3 token type\n");
+ goto out;
+ }
+
+ /* only support SPKM_MIC_TOK */
+ if((ptr[6] != 0x01) || (ptr[7] != 0x01)) {
+ dprintk("RPC: ERROR unsupported SPKM3 token \n");
+ goto out;
+ }
+
+ /* contextid */
+ if (ptr[8] != 0x03) {
+ dprintk("RPC: BAD SPKM3 asn1 context-id type\n");
+ goto out;
+ }
+
+ ctxelen = ptr[9];
+ if (ctxelen > 17) { /* length includes asn1 zbit octet */
+ dprintk("RPC: BAD SPKM3 contextid len %d\n", ctxelen);
+ goto out;
+ }
+
+ /* ignore ptr[10] */
+
+ if(!decode_asn1_bitstring(&spkm3_ctx_id, &ptr[11], ctxelen - 1, 16))
+ goto out;
+
+ /*
+ * in the current implementation: the optional int-alg is not present
+ * so the default int-alg (md5) is used the optional snd-seq field is
+ * also not present
+ */
+
+ if (*mic_hdrlen != 6 + ctxelen) {
+ dprintk("RPC: BAD SPKM_ MIC_TOK header len %d: we only support default int-alg (should be absent) and do not support snd-seq\n", *mic_hdrlen);
+ goto out;
+ }
+ /* checksum */
+ *cksum = (&ptr[10] + ctxelen); /* ctxelen includes ptr[10] */
+
+ ret = GSS_S_COMPLETE;
+out:
+ if (spkm3_ctx_id.data)
+ kfree(spkm3_ctx_id.data);
+ return ret;
+}
+
git://git.onelab.eu / linux-2.6.git / blobdiff