xref: /illumos-gate/usr/src/lib/smbclnt/libfknsmb/common/fksmb_sign_pkcs.c (revision 5016ae894be01e501342a67035ea848043662a45)
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  * Copyright 2022-2024 RackTop Systems, Inc.
15  */
16 
17 /*
18  * Helper functions for SMB signing using PKCS#11
19  *
20  * There are two implementations of these functions:
21  * This one (for user space) and another for kernel.
22  * See: uts/common/fs/smbclnt/netsmb/smb_sign_kcf.c
23  *
24  * Contrary to what one might assume from the file name,
25  * there should be NO SMB implementation knowledge here
26  * beyond a few carefully selected things (nsmb_kcrypt.h).
27  */
28 
29 #include <security/cryptoki.h>
30 #include <security/pkcs11.h>
31 #include <netsmb/nsmb_kcrypt.h>
32 
33 #include <stdlib.h>
34 #include <strings.h>
35 #include <sys/cmn_err.h>
36 
37 /*
38  * Common function to see if a mech is available.
39  */
40 static int
41 find_mech(smb_crypto_mech_t *mech, ulong_t mid)
42 {
43 	CK_SESSION_HANDLE hdl;
44 	CK_RV rv;
45 
46 	rv = SUNW_C_GetMechSession(mid, &hdl);
47 	if (rv != CKR_OK) {
48 		cmn_err(CE_NOTE, "PKCS#11: no mech 0x%x",
49 		    (unsigned int)mid);
50 		return (-1);
51 	}
52 	(void) C_CloseSession(hdl);
53 
54 	mech->mechanism = mid;
55 	mech->pParameter = NULL;
56 	mech->ulParameterLen = 0;
57 	return (0);
58 }
59 
60 /*
61  * SMB1 signing helpers:
62  * (getmech, init, update, final)
63  */
64 
65 /*
66  * Find out if we have this mech.
67  */
68 int
69 nsmb_md5_getmech(smb_crypto_mech_t *mech)
70 {
71 	return (find_mech(mech, CKM_MD5));
72 }
73 
74 /*
75  * Start PKCS#11 session.
76  */
77 int
78 nsmb_md5_init(smb_sign_ctx_t *ctxp, smb_crypto_mech_t *mech)
79 {
80 	CK_RV rv;
81 
82 	rv = SUNW_C_GetMechSession(mech->mechanism, ctxp);
83 	if (rv != CKR_OK)
84 		return (-1);
85 
86 	rv = C_DigestInit(*ctxp, mech);
87 
88 	return (rv == CKR_OK ? 0 : -1);
89 }
90 
91 /*
92  * Digest one segment
93  */
94 int
95 nsmb_md5_update(smb_sign_ctx_t ctx, void *buf, size_t len)
96 {
97 	CK_RV rv;
98 
99 	rv = C_DigestUpdate(ctx, buf, len);
100 	if (rv != CKR_OK)
101 		(void) C_CloseSession(ctx);
102 
103 	return (rv == CKR_OK ? 0 : -1);
104 }
105 
106 /*
107  * Get the final digest.
108  */
109 int
110 nsmb_md5_final(smb_sign_ctx_t ctx, uint8_t *digest16)
111 {
112 	CK_ULONG len = MD5_DIGEST_LENGTH;
113 	CK_RV rv;
114 
115 	rv = C_DigestFinal(ctx, digest16, &len);
116 	(void) C_CloseSession(ctx);
117 
118 	return (rv == CKR_OK ? 0 : -1);
119 }
120 
121 /*
122  * SMB2 signing helpers:
123  * (getmech, init, update, final)
124  */
125 
126 /*
127  * Find out if we have this mech.
128  */
129 int
130 nsmb_hmac_getmech(smb_crypto_mech_t *mech)
131 {
132 	return (find_mech(mech, CKM_SHA256_HMAC));
133 }
134 
135 /*
136  * Start PKCS#11 session, load the key.
137  */
138 int
139 nsmb_hmac_init(smb_sign_ctx_t *ctxp, smb_crypto_mech_t *mech,
140     uint8_t *key, size_t key_len)
141 {
142 	CK_OBJECT_HANDLE hkey = 0;
143 	CK_RV rv;
144 
145 	rv = SUNW_C_GetMechSession(mech->mechanism, ctxp);
146 	if (rv != CKR_OK)
147 		return (-1);
148 
149 	rv = SUNW_C_KeyToObject(*ctxp, mech->mechanism,
150 	    key, key_len, &hkey);
151 	if (rv != CKR_OK)
152 		return (-1);
153 
154 	rv = C_SignInit(*ctxp, mech, hkey);
155 	(void) C_DestroyObject(*ctxp, hkey);
156 
157 	return (rv == CKR_OK ? 0 : -1);
158 }
159 
160 /*
161  * Digest one segment
162  */
163 int
164 nsmb_hmac_update(smb_sign_ctx_t ctx, uint8_t *in, size_t len)
165 {
166 	CK_RV rv;
167 
168 	rv = C_SignUpdate(ctx, in, len);
169 	if (rv != CKR_OK)
170 		(void) C_CloseSession(ctx);
171 
172 	return (rv == CKR_OK ? 0 : -1);
173 }
174 
175 /*
176  * Note, the SMB2 signature is the first 16 bytes of the
177  * 32-byte SHA256 HMAC digest.  This is specifically for
178  * SMB2 signing, and NOT a generic HMAC function.
179  */
180 int
181 nsmb_hmac_final(smb_sign_ctx_t ctx, uint8_t *digest16)
182 {
183 	uint8_t full_digest[SHA256_DIGEST_LENGTH];
184 	CK_ULONG len = SHA256_DIGEST_LENGTH;
185 	CK_RV rv;
186 
187 	rv = C_SignFinal(ctx, full_digest, &len);
188 	if (rv == CKR_OK)
189 		bcopy(full_digest, digest16, 16);
190 
191 	(void) C_CloseSession(ctx);
192 
193 	return (rv == CKR_OK ? 0 : -1);
194 }
195 
196 /*
197  * One-shot HMAC function used in smb3_kdf
198  */
199 int
200 nsmb_hmac_one(smb_crypto_mech_t *mech,
201     uint8_t *key, size_t key_len,
202     uint8_t *data, size_t data_len,
203     uint8_t *mac, size_t mac_len)
204 {
205 	CK_SESSION_HANDLE hssn = 0;
206 	CK_OBJECT_HANDLE hkey = 0;
207 	CK_ULONG ck_maclen = mac_len;
208 	CK_RV rv;
209 	int rc = 0;
210 
211 	rv = SUNW_C_GetMechSession(mech->mechanism, &hssn);
212 	if (rv != CKR_OK)
213 		return (-1);
214 
215 	rv = SUNW_C_KeyToObject(hssn, mech->mechanism,
216 	    key, key_len, &hkey);
217 	if (rv != CKR_OK) {
218 		rc = -2;
219 		goto out;
220 	}
221 
222 	rv = C_SignInit(hssn, mech, hkey);
223 	if (rv != CKR_OK) {
224 		rc = -3;
225 		goto out;
226 	}
227 
228 	rv = C_Sign(hssn, data, data_len, mac, &ck_maclen);
229 	if (rv != CKR_OK) {
230 		rc = -4;
231 		goto out;
232 	}
233 
234 	if (ck_maclen != mac_len) {
235 		rc = -5;
236 		goto out;
237 	}
238 	rc = 0;
239 
240 out:
241 	if (hkey != 0)
242 		(void) C_DestroyObject(hssn, hkey);
243 	if (hssn != 0)
244 		(void) C_CloseSession(hssn);
245 
246 	return (rc);
247 }
248 
249 /*
250  * SMB3 signing helpers:
251  * (getmech, init, update, final)
252  */
253 
254 /*
255  * Find out if we have this mech.
256  */
257 int
258 nsmb_cmac_getmech(smb_crypto_mech_t *mech)
259 {
260 	return (find_mech(mech, CKM_AES_CMAC));
261 }
262 
263 /*
264  * Start PKCS#11 session, load the key.
265  */
266 int
267 nsmb_cmac_init(smb_sign_ctx_t *ctxp, smb_crypto_mech_t *mech,
268     uint8_t *key, size_t key_len)
269 {
270 	CK_OBJECT_HANDLE hkey = 0;
271 	CK_RV rv;
272 
273 	rv = SUNW_C_GetMechSession(mech->mechanism, ctxp);
274 	if (rv != CKR_OK)
275 		return (-1);
276 
277 	rv = SUNW_C_KeyToObject(*ctxp, mech->mechanism,
278 	    key, key_len, &hkey);
279 	if (rv != CKR_OK) {
280 		(void) C_CloseSession(*ctxp);
281 		return (-1);
282 	}
283 
284 	rv = C_SignInit(*ctxp, mech, hkey);
285 	(void) C_DestroyObject(*ctxp, hkey);
286 	if (rv != CKR_OK) {
287 		(void) C_CloseSession(*ctxp);
288 		return (-1);
289 	}
290 
291 	return (0);
292 }
293 
294 /*
295  * Digest one segment
296  */
297 int
298 nsmb_cmac_update(smb_sign_ctx_t ctx, uint8_t *in, size_t len)
299 {
300 	CK_RV rv;
301 
302 	rv = C_SignUpdate(ctx, in, len);
303 	if (rv != CKR_OK)
304 		(void) C_CloseSession(ctx);
305 
306 	return (rv == CKR_OK ? 0 : -1);
307 }
308 
309 /*
310  * Note, the SMB2 signature is just the AES CMAC digest.
311  * (both are 16 bytes long)
312  */
313 int
314 nsmb_cmac_final(smb_sign_ctx_t ctx, uint8_t *digest)
315 {
316 	CK_ULONG len = SMB2_SIG_SIZE;
317 	CK_RV rv;
318 
319 	rv = C_SignFinal(ctx, digest, &len);
320 	(void) C_CloseSession(ctx);
321 
322 	return (rv == CKR_OK ? 0 : -1);
323 }
324