1 /*
2  *  zcrypt 2.1.0
3  *
4  *  Copyright IBM Corp. 2001, 2006
5  *  Author(s): Robert Burroughs
6  *	       Eric Rossman (edrossma@us.ibm.com)
7  *
8  *  Hotplug & misc device support: Jochen Roehrig (roehrig@de.ibm.com)
9  *  Major cleanup & driver split: Martin Schwidefsky <schwidefsky@de.ibm.com>
10  *				  Ralph Wuerthner <rwuerthn@de.ibm.com>
11  *
12  * This program is free software; you can redistribute it and/or modify
13  * it under the terms of the GNU General Public License as published by
14  * the Free Software Foundation; either version 2, or (at your option)
15  * any later version.
16  *
17  * This program is distributed in the hope that it will be useful,
18  * but WITHOUT ANY WARRANTY; without even the implied warranty of
19  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
20  * GNU General Public License for more details.
21  *
22  * You should have received a copy of the GNU General Public License
23  * along with this program; if not, write to the Free Software
24  * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
25  */
26 
27 #define KMSG_COMPONENT "zcrypt"
28 #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
29 
30 #include <linux/module.h>
31 #include <linux/slab.h>
32 #include <linux/init.h>
33 #include <linux/err.h>
34 #include <linux/atomic.h>
35 #include <asm/uaccess.h>
36 
37 #include "ap_bus.h"
38 #include "zcrypt_api.h"
39 #include "zcrypt_error.h"
40 #include "zcrypt_pcica.h"
41 
42 #define PCICA_MIN_MOD_SIZE	  1	/*    8 bits	*/
43 #define PCICA_MAX_MOD_SIZE	256	/* 2048 bits	*/
44 
45 #define PCICA_SPEED_RATING	2800
46 
47 #define PCICA_MAX_MESSAGE_SIZE	0x3a0	/* sizeof(struct type4_lcr)	     */
48 #define PCICA_MAX_RESPONSE_SIZE 0x110	/* max outputdatalength + type80_hdr */
49 
50 #define PCICA_CLEANUP_TIME	(15*HZ)
51 
52 static struct ap_device_id zcrypt_pcica_ids[] = {
53 	{ AP_DEVICE(AP_DEVICE_TYPE_PCICA) },
54 	{ /* end of list */ },
55 };
56 
57 MODULE_DEVICE_TABLE(ap, zcrypt_pcica_ids);
58 MODULE_AUTHOR("IBM Corporation");
59 MODULE_DESCRIPTION("PCICA Cryptographic Coprocessor device driver, "
60 		   "Copyright IBM Corp. 2001, 2006");
61 MODULE_LICENSE("GPL");
62 
63 static int zcrypt_pcica_probe(struct ap_device *ap_dev);
64 static void zcrypt_pcica_remove(struct ap_device *ap_dev);
65 static void zcrypt_pcica_receive(struct ap_device *, struct ap_message *,
66 				 struct ap_message *);
67 
68 static struct ap_driver zcrypt_pcica_driver = {
69 	.probe = zcrypt_pcica_probe,
70 	.remove = zcrypt_pcica_remove,
71 	.ids = zcrypt_pcica_ids,
72 	.request_timeout = PCICA_CLEANUP_TIME,
73 };
74 
75 /**
76  * Convert a ICAMEX message to a type4 MEX message.
77  *
78  * @zdev: crypto device pointer
79  * @zreq: crypto request pointer
80  * @mex: pointer to user input data
81  *
82  * Returns 0 on success or -EFAULT.
83  */
ICAMEX_msg_to_type4MEX_msg(struct zcrypt_device * zdev,struct ap_message * ap_msg,struct ica_rsa_modexpo * mex)84 static int ICAMEX_msg_to_type4MEX_msg(struct zcrypt_device *zdev,
85 				      struct ap_message *ap_msg,
86 				      struct ica_rsa_modexpo *mex)
87 {
88 	unsigned char *modulus, *exponent, *message;
89 	int mod_len;
90 
91 	mod_len = mex->inputdatalength;
92 
93 	if (mod_len <= 128) {
94 		struct type4_sme *sme = ap_msg->message;
95 		memset(sme, 0, sizeof(*sme));
96 		ap_msg->length = sizeof(*sme);
97 		sme->header.msg_fmt = TYPE4_SME_FMT;
98 		sme->header.msg_len = sizeof(*sme);
99 		sme->header.msg_type_code = TYPE4_TYPE_CODE;
100 		sme->header.request_code = TYPE4_REQU_CODE;
101 		modulus = sme->modulus + sizeof(sme->modulus) - mod_len;
102 		exponent = sme->exponent + sizeof(sme->exponent) - mod_len;
103 		message = sme->message + sizeof(sme->message) - mod_len;
104 	} else {
105 		struct type4_lme *lme = ap_msg->message;
106 		memset(lme, 0, sizeof(*lme));
107 		ap_msg->length = sizeof(*lme);
108 		lme->header.msg_fmt = TYPE4_LME_FMT;
109 		lme->header.msg_len = sizeof(*lme);
110 		lme->header.msg_type_code = TYPE4_TYPE_CODE;
111 		lme->header.request_code = TYPE4_REQU_CODE;
112 		modulus = lme->modulus + sizeof(lme->modulus) - mod_len;
113 		exponent = lme->exponent + sizeof(lme->exponent) - mod_len;
114 		message = lme->message + sizeof(lme->message) - mod_len;
115 	}
116 
117 	if (copy_from_user(modulus, mex->n_modulus, mod_len) ||
118 	    copy_from_user(exponent, mex->b_key, mod_len) ||
119 	    copy_from_user(message, mex->inputdata, mod_len))
120 		return -EFAULT;
121 	return 0;
122 }
123 
124 /**
125  * Convert a ICACRT message to a type4 CRT message.
126  *
127  * @zdev: crypto device pointer
128  * @zreq: crypto request pointer
129  * @crt: pointer to user input data
130  *
131  * Returns 0 on success or -EFAULT.
132  */
ICACRT_msg_to_type4CRT_msg(struct zcrypt_device * zdev,struct ap_message * ap_msg,struct ica_rsa_modexpo_crt * crt)133 static int ICACRT_msg_to_type4CRT_msg(struct zcrypt_device *zdev,
134 				      struct ap_message *ap_msg,
135 				      struct ica_rsa_modexpo_crt *crt)
136 {
137 	unsigned char *p, *q, *dp, *dq, *u, *inp;
138 	int mod_len, short_len, long_len;
139 
140 	mod_len = crt->inputdatalength;
141 	short_len = mod_len / 2;
142 	long_len = mod_len / 2 + 8;
143 
144 	if (mod_len <= 128) {
145 		struct type4_scr *scr = ap_msg->message;
146 		memset(scr, 0, sizeof(*scr));
147 		ap_msg->length = sizeof(*scr);
148 		scr->header.msg_type_code = TYPE4_TYPE_CODE;
149 		scr->header.request_code = TYPE4_REQU_CODE;
150 		scr->header.msg_fmt = TYPE4_SCR_FMT;
151 		scr->header.msg_len = sizeof(*scr);
152 		p = scr->p + sizeof(scr->p) - long_len;
153 		q = scr->q + sizeof(scr->q) - short_len;
154 		dp = scr->dp + sizeof(scr->dp) - long_len;
155 		dq = scr->dq + sizeof(scr->dq) - short_len;
156 		u = scr->u + sizeof(scr->u) - long_len;
157 		inp = scr->message + sizeof(scr->message) - mod_len;
158 	} else {
159 		struct type4_lcr *lcr = ap_msg->message;
160 		memset(lcr, 0, sizeof(*lcr));
161 		ap_msg->length = sizeof(*lcr);
162 		lcr->header.msg_type_code = TYPE4_TYPE_CODE;
163 		lcr->header.request_code = TYPE4_REQU_CODE;
164 		lcr->header.msg_fmt = TYPE4_LCR_FMT;
165 		lcr->header.msg_len = sizeof(*lcr);
166 		p = lcr->p + sizeof(lcr->p) - long_len;
167 		q = lcr->q + sizeof(lcr->q) - short_len;
168 		dp = lcr->dp + sizeof(lcr->dp) - long_len;
169 		dq = lcr->dq + sizeof(lcr->dq) - short_len;
170 		u = lcr->u + sizeof(lcr->u) - long_len;
171 		inp = lcr->message + sizeof(lcr->message) - mod_len;
172 	}
173 
174 	if (copy_from_user(p, crt->np_prime, long_len) ||
175 	    copy_from_user(q, crt->nq_prime, short_len) ||
176 	    copy_from_user(dp, crt->bp_key, long_len) ||
177 	    copy_from_user(dq, crt->bq_key, short_len) ||
178 	    copy_from_user(u, crt->u_mult_inv, long_len) ||
179 	    copy_from_user(inp, crt->inputdata, mod_len))
180 		return -EFAULT;
181 	return 0;
182 }
183 
184 /**
185  * Copy results from a type 84 reply message back to user space.
186  *
187  * @zdev: crypto device pointer
188  * @reply: reply AP message.
189  * @data: pointer to user output data
190  * @length: size of user output data
191  *
192  * Returns 0 on success or -EFAULT.
193  */
convert_type84(struct zcrypt_device * zdev,struct ap_message * reply,char __user * outputdata,unsigned int outputdatalength)194 static int convert_type84(struct zcrypt_device *zdev,
195 			  struct ap_message *reply,
196 			  char __user *outputdata,
197 			  unsigned int outputdatalength)
198 {
199 	struct type84_hdr *t84h = reply->message;
200 	char *data;
201 
202 	if (t84h->len < sizeof(*t84h) + outputdatalength) {
203 		/* The result is too short, the PCICA card may not do that.. */
204 		zdev->online = 0;
205 		pr_err("Cryptographic device %x failed and was set offline\n",
206 		       zdev->ap_dev->qid);
207 		ZCRYPT_DBF_DEV(DBF_ERR, zdev, "dev%04xo%drc%d",
208 			       zdev->ap_dev->qid, zdev->online, t84h->code);
209 		return -EAGAIN;	/* repeat the request on a different device. */
210 	}
211 	BUG_ON(t84h->len > PCICA_MAX_RESPONSE_SIZE);
212 	data = reply->message + t84h->len - outputdatalength;
213 	if (copy_to_user(outputdata, data, outputdatalength))
214 		return -EFAULT;
215 	return 0;
216 }
217 
convert_response(struct zcrypt_device * zdev,struct ap_message * reply,char __user * outputdata,unsigned int outputdatalength)218 static int convert_response(struct zcrypt_device *zdev,
219 			    struct ap_message *reply,
220 			    char __user *outputdata,
221 			    unsigned int outputdatalength)
222 {
223 	/* Response type byte is the second byte in the response. */
224 	switch (((unsigned char *) reply->message)[1]) {
225 	case TYPE82_RSP_CODE:
226 	case TYPE88_RSP_CODE:
227 		return convert_error(zdev, reply);
228 	case TYPE84_RSP_CODE:
229 		return convert_type84(zdev, reply,
230 				      outputdata, outputdatalength);
231 	default: /* Unknown response type, this should NEVER EVER happen */
232 		zdev->online = 0;
233 		pr_err("Cryptographic device %x failed and was set offline\n",
234 		       zdev->ap_dev->qid);
235 		ZCRYPT_DBF_DEV(DBF_ERR, zdev, "dev%04xo%dfail",
236 			       zdev->ap_dev->qid, zdev->online);
237 		return -EAGAIN;	/* repeat the request on a different device. */
238 	}
239 }
240 
241 /**
242  * This function is called from the AP bus code after a crypto request
243  * "msg" has finished with the reply message "reply".
244  * It is called from tasklet context.
245  * @ap_dev: pointer to the AP device
246  * @msg: pointer to the AP message
247  * @reply: pointer to the AP reply message
248  */
zcrypt_pcica_receive(struct ap_device * ap_dev,struct ap_message * msg,struct ap_message * reply)249 static void zcrypt_pcica_receive(struct ap_device *ap_dev,
250 				 struct ap_message *msg,
251 				 struct ap_message *reply)
252 {
253 	static struct error_hdr error_reply = {
254 		.type = TYPE82_RSP_CODE,
255 		.reply_code = REP82_ERROR_MACHINE_FAILURE,
256 	};
257 	struct type84_hdr *t84h;
258 	int length;
259 
260 	/* Copy the reply message to the request message buffer. */
261 	if (IS_ERR(reply)) {
262 		memcpy(msg->message, &error_reply, sizeof(error_reply));
263 		goto out;
264 	}
265 	t84h = reply->message;
266 	if (t84h->code == TYPE84_RSP_CODE) {
267 		length = min(PCICA_MAX_RESPONSE_SIZE, (int) t84h->len);
268 		memcpy(msg->message, reply->message, length);
269 	} else
270 		memcpy(msg->message, reply->message, sizeof error_reply);
271 out:
272 	complete((struct completion *) msg->private);
273 }
274 
275 static atomic_t zcrypt_step = ATOMIC_INIT(0);
276 
277 /**
278  * The request distributor calls this function if it picked the PCICA
279  * device to handle a modexpo request.
280  * @zdev: pointer to zcrypt_device structure that identifies the
281  *	  PCICA device to the request distributor
282  * @mex: pointer to the modexpo request buffer
283  */
zcrypt_pcica_modexpo(struct zcrypt_device * zdev,struct ica_rsa_modexpo * mex)284 static long zcrypt_pcica_modexpo(struct zcrypt_device *zdev,
285 				 struct ica_rsa_modexpo *mex)
286 {
287 	struct ap_message ap_msg;
288 	struct completion work;
289 	int rc;
290 
291 	ap_init_message(&ap_msg);
292 	ap_msg.message = kmalloc(PCICA_MAX_MESSAGE_SIZE, GFP_KERNEL);
293 	if (!ap_msg.message)
294 		return -ENOMEM;
295 	ap_msg.receive = zcrypt_pcica_receive;
296 	ap_msg.psmid = (((unsigned long long) current->pid) << 32) +
297 				atomic_inc_return(&zcrypt_step);
298 	ap_msg.private = &work;
299 	rc = ICAMEX_msg_to_type4MEX_msg(zdev, &ap_msg, mex);
300 	if (rc)
301 		goto out_free;
302 	init_completion(&work);
303 	ap_queue_message(zdev->ap_dev, &ap_msg);
304 	rc = wait_for_completion_interruptible(&work);
305 	if (rc == 0)
306 		rc = convert_response(zdev, &ap_msg, mex->outputdata,
307 				      mex->outputdatalength);
308 	else
309 		/* Signal pending. */
310 		ap_cancel_message(zdev->ap_dev, &ap_msg);
311 out_free:
312 	kfree(ap_msg.message);
313 	return rc;
314 }
315 
316 /**
317  * The request distributor calls this function if it picked the PCICA
318  * device to handle a modexpo_crt request.
319  * @zdev: pointer to zcrypt_device structure that identifies the
320  *	  PCICA device to the request distributor
321  * @crt: pointer to the modexpoc_crt request buffer
322  */
zcrypt_pcica_modexpo_crt(struct zcrypt_device * zdev,struct ica_rsa_modexpo_crt * crt)323 static long zcrypt_pcica_modexpo_crt(struct zcrypt_device *zdev,
324 				     struct ica_rsa_modexpo_crt *crt)
325 {
326 	struct ap_message ap_msg;
327 	struct completion work;
328 	int rc;
329 
330 	ap_init_message(&ap_msg);
331 	ap_msg.message = kmalloc(PCICA_MAX_MESSAGE_SIZE, GFP_KERNEL);
332 	if (!ap_msg.message)
333 		return -ENOMEM;
334 	ap_msg.receive = zcrypt_pcica_receive;
335 	ap_msg.psmid = (((unsigned long long) current->pid) << 32) +
336 				atomic_inc_return(&zcrypt_step);
337 	ap_msg.private = &work;
338 	rc = ICACRT_msg_to_type4CRT_msg(zdev, &ap_msg, crt);
339 	if (rc)
340 		goto out_free;
341 	init_completion(&work);
342 	ap_queue_message(zdev->ap_dev, &ap_msg);
343 	rc = wait_for_completion_interruptible(&work);
344 	if (rc == 0)
345 		rc = convert_response(zdev, &ap_msg, crt->outputdata,
346 				      crt->outputdatalength);
347 	else
348 		/* Signal pending. */
349 		ap_cancel_message(zdev->ap_dev, &ap_msg);
350 out_free:
351 	kfree(ap_msg.message);
352 	return rc;
353 }
354 
355 /**
356  * The crypto operations for a PCICA card.
357  */
358 static struct zcrypt_ops zcrypt_pcica_ops = {
359 	.rsa_modexpo = zcrypt_pcica_modexpo,
360 	.rsa_modexpo_crt = zcrypt_pcica_modexpo_crt,
361 };
362 
363 /**
364  * Probe function for PCICA cards. It always accepts the AP device
365  * since the bus_match already checked the hardware type.
366  * @ap_dev: pointer to the AP device.
367  */
zcrypt_pcica_probe(struct ap_device * ap_dev)368 static int zcrypt_pcica_probe(struct ap_device *ap_dev)
369 {
370 	struct zcrypt_device *zdev;
371 	int rc;
372 
373 	zdev = zcrypt_device_alloc(PCICA_MAX_RESPONSE_SIZE);
374 	if (!zdev)
375 		return -ENOMEM;
376 	zdev->ap_dev = ap_dev;
377 	zdev->ops = &zcrypt_pcica_ops;
378 	zdev->online = 1;
379 	zdev->user_space_type = ZCRYPT_PCICA;
380 	zdev->type_string = "PCICA";
381 	zdev->min_mod_size = PCICA_MIN_MOD_SIZE;
382 	zdev->max_mod_size = PCICA_MAX_MOD_SIZE;
383 	zdev->speed_rating = PCICA_SPEED_RATING;
384 	zdev->max_exp_bit_length = PCICA_MAX_MOD_SIZE;
385 	ap_dev->reply = &zdev->reply;
386 	ap_dev->private = zdev;
387 	rc = zcrypt_device_register(zdev);
388 	if (rc)
389 		goto out_free;
390 	return 0;
391 
392 out_free:
393 	ap_dev->private = NULL;
394 	zcrypt_device_free(zdev);
395 	return rc;
396 }
397 
398 /**
399  * This is called to remove the extended PCICA driver information
400  * if an AP device is removed.
401  */
zcrypt_pcica_remove(struct ap_device * ap_dev)402 static void zcrypt_pcica_remove(struct ap_device *ap_dev)
403 {
404 	struct zcrypt_device *zdev = ap_dev->private;
405 
406 	zcrypt_device_unregister(zdev);
407 }
408 
zcrypt_pcica_init(void)409 int __init zcrypt_pcica_init(void)
410 {
411 	return ap_driver_register(&zcrypt_pcica_driver, THIS_MODULE, "pcica");
412 }
413 
zcrypt_pcica_exit(void)414 void zcrypt_pcica_exit(void)
415 {
416 	ap_driver_unregister(&zcrypt_pcica_driver);
417 }
418 
419 module_init(zcrypt_pcica_init);
420 module_exit(zcrypt_pcica_exit);
421