diff options
Diffstat (limited to 'net/sunrpc/auth_gss/gss_spkm3_token.c')
| -rw-r--r-- | net/sunrpc/auth_gss/gss_spkm3_token.c | 266 |
1 files changed, 266 insertions, 0 deletions
diff --git a/net/sunrpc/auth_gss/gss_spkm3_token.c b/net/sunrpc/auth_gss/gss_spkm3_token.c new file mode 100644 index 000000000000..46c08a0710f6 --- /dev/null +++ b/net/sunrpc/auth_gss/gss_spkm3_token.c @@ -0,0 +1,266 @@ +/* + * 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; +} + |