1 /*
2  * This file and its contents are supplied under the terms of the
3  * Common Development and Distribution License ("CDDL"), version 1.0.
4  * You may only use this file in accordance with the terms of version
5  * 1.0 of the CDDL.
6  *
7  * A full copy of the text of the CDDL should have accompanied this
8  * source.  A copy of the CDDL is also available via the Internet at
9  * http://www.illumos.org/license/CDDL.
10  */
11 
12 /*
13  * Copyright 2017 Nexenta Systems, Inc.  All rights reserved.
14  */
15 
16 /*
17  * Helper functions for SMB signing using PKCS#11
18  *
19  * There are two implementations of these functions:
20  * This one (for user space) and another for kernel.
21  * See: uts/common/fs/smbclnt/netsmb/smb_sign_kcf.c
22  */
23 
24 #include <stdlib.h>
25 #include <strings.h>
26 #include <sys/cmn_err.h>
27 #include <netsmb/smb_signing.h>
28 #include <security/cryptoki.h>
29 #include <security/pkcs11.h>
30 
31 /*
32  * Common function to see if a mech is available.
33  */
34 static int
find_mech(smb_sign_mech_t * mech,ulong_t mid)35 find_mech(smb_sign_mech_t *mech, ulong_t mid)
36 {
37 	CK_SESSION_HANDLE hdl;
38 	CK_RV rv;
39 
40 	rv = SUNW_C_GetMechSession(mid, &hdl);
41 	if (rv != CKR_OK) {
42 		cmn_err(CE_NOTE, "PKCS#11: no mech 0x%x",
43 		    (unsigned int)mid);
44 		return (-1);
45 	}
46 	(void) C_CloseSession(hdl);
47 
48 	mech->mechanism = mid;
49 	mech->pParameter = NULL;
50 	mech->ulParameterLen = 0;
51 	return (0);
52 }
53 
54 /*
55  * SMB1 signing helpers:
56  * (getmech, init, update, final)
57  */
58 
59 /*
60  * Find out if we have this mech.
61  */
62 int
smb_md5_getmech(smb_sign_mech_t * mech)63 smb_md5_getmech(smb_sign_mech_t *mech)
64 {
65 	return (find_mech(mech, CKM_MD5));
66 }
67 
68 /*
69  * Start PKCS#11 session.
70  */
71 int
smb_md5_init(smb_sign_ctx_t * ctxp,smb_sign_mech_t * mech)72 smb_md5_init(smb_sign_ctx_t *ctxp, smb_sign_mech_t *mech)
73 {
74 	CK_RV rv;
75 
76 	rv = SUNW_C_GetMechSession(mech->mechanism, ctxp);
77 	if (rv != CKR_OK)
78 		return (-1);
79 
80 	rv = C_DigestInit(*ctxp, mech);
81 
82 	return (rv == CKR_OK ? 0 : -1);
83 }
84 
85 /*
86  * Digest one segment
87  */
88 int
smb_md5_update(smb_sign_ctx_t ctx,void * buf,size_t len)89 smb_md5_update(smb_sign_ctx_t ctx, void *buf, size_t len)
90 {
91 	CK_RV rv;
92 
93 	rv = C_DigestUpdate(ctx, buf, len);
94 	if (rv != CKR_OK)
95 		(void) C_CloseSession(ctx);
96 
97 	return (rv == CKR_OK ? 0 : -1);
98 }
99 
100 /*
101  * Get the final digest.
102  */
103 int
smb_md5_final(smb_sign_ctx_t ctx,uint8_t * digest16)104 smb_md5_final(smb_sign_ctx_t ctx, uint8_t *digest16)
105 {
106 	CK_ULONG len = MD5_DIGEST_LENGTH;
107 	CK_RV rv;
108 
109 	rv = C_DigestFinal(ctx, digest16, &len);
110 	(void) C_CloseSession(ctx);
111 
112 	return (rv == CKR_OK ? 0 : -1);
113 }
114 
115 /*
116  * SMB2 signing helpers:
117  * (getmech, init, update, final)
118  */
119 
120 /*
121  * Find out if we have this mech.
122  */
123 int
smb2_hmac_getmech(smb_sign_mech_t * mech)124 smb2_hmac_getmech(smb_sign_mech_t *mech)
125 {
126 	return (find_mech(mech, CKM_SHA256_HMAC));
127 }
128 
129 /*
130  * Start PKCS#11 session, load the key.
131  */
132 int
smb2_hmac_init(smb_sign_ctx_t * ctxp,smb_sign_mech_t * mech,uint8_t * key,size_t key_len)133 smb2_hmac_init(smb_sign_ctx_t *ctxp, smb_sign_mech_t *mech,
134     uint8_t *key, size_t key_len)
135 {
136 	CK_OBJECT_HANDLE hkey = 0;
137 	CK_RV rv;
138 
139 	rv = SUNW_C_GetMechSession(mech->mechanism, ctxp);
140 	if (rv != CKR_OK)
141 		return (-1);
142 
143 	rv = SUNW_C_KeyToObject(*ctxp, mech->mechanism,
144 	    key, key_len, &hkey);
145 	if (rv != CKR_OK)
146 		return (-1);
147 
148 	rv = C_SignInit(*ctxp, mech, hkey);
149 	(void) C_DestroyObject(*ctxp, hkey);
150 
151 	return (rv == CKR_OK ? 0 : -1);
152 }
153 
154 /*
155  * Digest one segment
156  */
157 int
smb2_hmac_update(smb_sign_ctx_t ctx,uint8_t * in,size_t len)158 smb2_hmac_update(smb_sign_ctx_t ctx, uint8_t *in, size_t len)
159 {
160 	CK_RV rv;
161 
162 	rv = C_SignUpdate(ctx, in, len);
163 	if (rv != CKR_OK)
164 		(void) C_CloseSession(ctx);
165 
166 	return (rv == CKR_OK ? 0 : -1);
167 }
168 
169 /*
170  * Note, the SMB2 signature is the first 16 bytes of the
171  * 32-byte SHA256 HMAC digest.
172  */
173 int
smb2_hmac_final(smb_sign_ctx_t ctx,uint8_t * digest16)174 smb2_hmac_final(smb_sign_ctx_t ctx, uint8_t *digest16)
175 {
176 	uint8_t full_digest[SHA256_DIGEST_LENGTH];
177 	CK_ULONG len = SHA256_DIGEST_LENGTH;
178 	CK_RV rv;
179 
180 	rv = C_SignFinal(ctx, full_digest, &len);
181 	if (rv == CKR_OK)
182 		bcopy(full_digest, digest16, 16);
183 
184 	(void) C_CloseSession(ctx);
185 
186 	return (rv == CKR_OK ? 0 : -1);
187 }
188 
189 /*
190  * SMB3 signing helpers:
191  * (getmech, init, update, final)
192  */
193 
194 /*
195  * Find out if we have this mech.
196  */
197 int
smb3_cmac_getmech(smb_sign_mech_t * mech)198 smb3_cmac_getmech(smb_sign_mech_t *mech)
199 {
200 	return (find_mech(mech, CKM_AES_CMAC));
201 }
202 
203 /*
204  * Start PKCS#11 session, load the key.
205  */
206 int
smb3_cmac_init(smb_sign_ctx_t * ctxp,smb_sign_mech_t * mech,uint8_t * key,size_t key_len)207 smb3_cmac_init(smb_sign_ctx_t *ctxp, smb_sign_mech_t *mech,
208     uint8_t *key, size_t key_len)
209 {
210 	CK_OBJECT_HANDLE hkey = 0;
211 	CK_RV rv;
212 
213 	rv = SUNW_C_GetMechSession(mech->mechanism, ctxp);
214 	if (rv != CKR_OK)
215 		return (-1);
216 
217 	rv = SUNW_C_KeyToObject(*ctxp, mech->mechanism,
218 	    key, key_len, &hkey);
219 	if (rv != CKR_OK) {
220 		(void) C_CloseSession(*ctxp);
221 		return (-1);
222 	}
223 
224 	rv = C_SignInit(*ctxp, mech, hkey);
225 	(void) C_DestroyObject(*ctxp, hkey);
226 	if (rv != CKR_OK) {
227 		(void) C_CloseSession(*ctxp);
228 		return (-1);
229 	}
230 
231 	return (0);
232 }
233 
234 /*
235  * Digest one segment
236  */
237 int
smb3_cmac_update(smb_sign_ctx_t ctx,uint8_t * in,size_t len)238 smb3_cmac_update(smb_sign_ctx_t ctx, uint8_t *in, size_t len)
239 {
240 	CK_RV rv;
241 
242 	rv = C_SignUpdate(ctx, in, len);
243 	if (rv != CKR_OK)
244 		(void) C_CloseSession(ctx);
245 
246 	return (rv == CKR_OK ? 0 : -1);
247 }
248 
249 /*
250  * Note, the SMB2 signature is just the AES CMAC digest.
251  * (both are 16 bytes long)
252  */
253 int
smb3_cmac_final(smb_sign_ctx_t ctx,uint8_t * digest)254 smb3_cmac_final(smb_sign_ctx_t ctx, uint8_t *digest)
255 {
256 	CK_ULONG len = SMB2_SIG_SIZE;
257 	CK_RV rv;
258 
259 	rv = C_SignFinal(ctx, digest, &len);
260 	(void) C_CloseSession(ctx);
261 
262 	return (rv == CKR_OK ? 0 : -1);
263 }
264