1 /*
2 * linux/net/sunrpc/gss_spkm3_seal.c
3 *
4 * Copyright (c) 2003 The Regents of the University of Michigan.
5 * All rights reserved.
6 *
7 * Andy Adamson <andros@umich.edu>
8 *
9 * Redistribution and use in source and binary forms, with or without
10 * modification, are permitted provided that the following conditions
11 * are met:
12 *
13 * 1. Redistributions of source code must retain the above copyright
14 * notice, this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright
16 * notice, this list of conditions and the following disclaimer in the
17 * documentation and/or other materials provided with the distribution.
18 * 3. Neither the name of the University nor the names of its
19 * contributors may be used to endorse or promote products derived
20 * from this software without specific prior written permission.
21 *
22 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED
23 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
24 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
25 * DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
27 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
28 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
29 * BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
30 * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
31 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
32 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
33 *
34 */
35
36 #include <linux/types.h>
37 #include <linux/slab.h>
38 #include <linux/jiffies.h>
39 #include <linux/sunrpc/gss_spkm3.h>
40 #include <linux/random.h>
41 #include <linux/crypto.h>
42 #include <linux/pagemap.h>
43 #include <linux/scatterlist.h>
44 #include <linux/sunrpc/xdr.h>
45
46 #ifdef RPC_DEBUG
47 # define RPCDBG_FACILITY RPCDBG_AUTH
48 #endif
49
50 const struct xdr_netobj hmac_md5_oid = { 8, "\x2B\x06\x01\x05\x05\x08\x01\x01"};
51 const struct xdr_netobj cast5_cbc_oid = {9, "\x2A\x86\x48\x86\xF6\x7D\x07\x42\x0A"};
52
53 /*
54 * spkm3_make_token()
55 *
56 * Only SPKM_MIC_TOK with md5 intg-alg is supported
57 */
58
59 u32
spkm3_make_token(struct spkm3_ctx * ctx,struct xdr_buf * text,struct xdr_netobj * token,int toktype)60 spkm3_make_token(struct spkm3_ctx *ctx,
61 struct xdr_buf * text, struct xdr_netobj * token,
62 int toktype)
63 {
64 s32 checksum_type;
65 char tokhdrbuf[25];
66 char cksumdata[16];
67 struct xdr_netobj md5cksum = {.len = 0, .data = cksumdata};
68 struct xdr_netobj mic_hdr = {.len = 0, .data = tokhdrbuf};
69 int tokenlen = 0;
70 unsigned char *ptr;
71 s32 now;
72 int ctxelen = 0, ctxzbit = 0;
73 int md5elen = 0, md5zbit = 0;
74
75 now = jiffies;
76
77 if (ctx->ctx_id.len != 16) {
78 dprintk("RPC: spkm3_make_token BAD ctx_id.len %d\n",
79 ctx->ctx_id.len);
80 goto out_err;
81 }
82
83 if (!g_OID_equal(&ctx->intg_alg, &hmac_md5_oid)) {
84 dprintk("RPC: gss_spkm3_seal: unsupported I-ALG "
85 "algorithm. only support hmac-md5 I-ALG.\n");
86 goto out_err;
87 } else
88 checksum_type = CKSUMTYPE_HMAC_MD5;
89
90 if (!g_OID_equal(&ctx->conf_alg, &cast5_cbc_oid)) {
91 dprintk("RPC: gss_spkm3_seal: unsupported C-ALG "
92 "algorithm\n");
93 goto out_err;
94 }
95
96 if (toktype == SPKM_MIC_TOK) {
97 /* Calculate checksum over the mic-header */
98 asn1_bitstring_len(&ctx->ctx_id, &ctxelen, &ctxzbit);
99 spkm3_mic_header(&mic_hdr.data, &mic_hdr.len, ctx->ctx_id.data,
100 ctxelen, ctxzbit);
101 if (make_spkm3_checksum(checksum_type, &ctx->derived_integ_key,
102 (char *)mic_hdr.data, mic_hdr.len,
103 text, 0, &md5cksum))
104 goto out_err;
105
106 asn1_bitstring_len(&md5cksum, &md5elen, &md5zbit);
107 tokenlen = 10 + ctxelen + 1 + md5elen + 1;
108
109 /* Create token header using generic routines */
110 token->len = g_token_size(&ctx->mech_used, tokenlen + 2);
111
112 ptr = token->data;
113 g_make_token_header(&ctx->mech_used, tokenlen + 2, &ptr);
114
115 spkm3_make_mic_token(&ptr, tokenlen, &mic_hdr, &md5cksum, md5elen, md5zbit);
116 } else if (toktype == SPKM_WRAP_TOK) { /* Not Supported */
117 dprintk("RPC: gss_spkm3_seal: SPKM_WRAP_TOK "
118 "not supported\n");
119 goto out_err;
120 }
121
122 /* XXX need to implement sequence numbers, and ctx->expired */
123
124 return GSS_S_COMPLETE;
125 out_err:
126 token->data = NULL;
127 token->len = 0;
128 return GSS_S_FAILURE;
129 }
130
131 static int
spkm3_checksummer(struct scatterlist * sg,void * data)132 spkm3_checksummer(struct scatterlist *sg, void *data)
133 {
134 struct hash_desc *desc = data;
135
136 return crypto_hash_update(desc, sg, sg->length);
137 }
138
139 /* checksum the plaintext data and hdrlen bytes of the token header */
140 s32
make_spkm3_checksum(s32 cksumtype,struct xdr_netobj * key,char * header,unsigned int hdrlen,struct xdr_buf * body,unsigned int body_offset,struct xdr_netobj * cksum)141 make_spkm3_checksum(s32 cksumtype, struct xdr_netobj *key, char *header,
142 unsigned int hdrlen, struct xdr_buf *body,
143 unsigned int body_offset, struct xdr_netobj *cksum)
144 {
145 char *cksumname;
146 struct hash_desc desc; /* XXX add to ctx? */
147 struct scatterlist sg[1];
148 int err;
149
150 switch (cksumtype) {
151 case CKSUMTYPE_HMAC_MD5:
152 cksumname = "hmac(md5)";
153 break;
154 default:
155 dprintk("RPC: spkm3_make_checksum:"
156 " unsupported checksum %d", cksumtype);
157 return GSS_S_FAILURE;
158 }
159
160 if (key->data == NULL || key->len <= 0) return GSS_S_FAILURE;
161
162 desc.tfm = crypto_alloc_hash(cksumname, 0, CRYPTO_ALG_ASYNC);
163 if (IS_ERR(desc.tfm))
164 return GSS_S_FAILURE;
165 cksum->len = crypto_hash_digestsize(desc.tfm);
166 desc.flags = CRYPTO_TFM_REQ_MAY_SLEEP;
167
168 err = crypto_hash_setkey(desc.tfm, key->data, key->len);
169 if (err)
170 goto out;
171
172 err = crypto_hash_init(&desc);
173 if (err)
174 goto out;
175
176 sg_init_one(sg, header, hdrlen);
177 crypto_hash_update(&desc, sg, sg->length);
178
179 xdr_process_buf(body, body_offset, body->len - body_offset,
180 spkm3_checksummer, &desc);
181 crypto_hash_final(&desc, cksum->data);
182
183 out:
184 crypto_free_hash(desc.tfm);
185
186 return err ? GSS_S_FAILURE : 0;
187 }
188