1/*
2 *  zcrypt 2.1.0
3 *
4 *  Copyright IBM Corp. 2001, 2012
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 *  MSGTYPE restruct:		  Holger Dengler <hd@linux.vnet.ibm.com>
12 *
13 * This program is free software; you can redistribute it and/or modify
14 * it under the terms of the GNU General Public License as published by
15 * the Free Software Foundation; either version 2, or (at your option)
16 * any later version.
17 *
18 * This program is distributed in the hope that it will be useful,
19 * but WITHOUT ANY WARRANTY; without even the implied warranty of
20 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
21 * GNU General Public License for more details.
22 *
23 * You should have received a copy of the GNU General Public License
24 * along with this program; if not, write to the Free Software
25 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
26 */
27
28#define KMSG_COMPONENT "zcrypt"
29#define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
30
31#include <linux/module.h>
32#include <linux/slab.h>
33#include <linux/init.h>
34#include <linux/err.h>
35#include <linux/atomic.h>
36#include <linux/uaccess.h>
37
38#include "ap_bus.h"
39#include "zcrypt_api.h"
40#include "zcrypt_error.h"
41#include "zcrypt_msgtype50.h"
42
43#define CEX3A_MAX_MOD_SIZE	512	/* 4096 bits	*/
44
45#define CEX2A_MAX_RESPONSE_SIZE 0x110	/* max outputdatalength + type80_hdr */
46
47#define CEX3A_MAX_RESPONSE_SIZE	0x210	/* 512 bit modulus
48					 * (max outputdatalength) +
49					 * type80_hdr*/
50
51MODULE_AUTHOR("IBM Corporation");
52MODULE_DESCRIPTION("Cryptographic Accelerator (message type 50), " \
53		   "Copyright IBM Corp. 2001, 2012");
54MODULE_LICENSE("GPL");
55
56static void zcrypt_cex2a_receive(struct ap_device *, struct ap_message *,
57				 struct ap_message *);
58
59/**
60 * The type 50 message family is associated with a CEX2A card.
61 *
62 * The four members of the family are described below.
63 *
64 * Note that all unsigned char arrays are right-justified and left-padded
65 * with zeroes.
66 *
67 * Note that all reserved fields must be zeroes.
68 */
69struct type50_hdr {
70	unsigned char	reserved1;
71	unsigned char	msg_type_code;	/* 0x50 */
72	unsigned short	msg_len;
73	unsigned char	reserved2;
74	unsigned char	ignored;
75	unsigned short	reserved3;
76} __packed;
77
78#define TYPE50_TYPE_CODE	0x50
79
80#define TYPE50_MEB1_FMT		0x0001
81#define TYPE50_MEB2_FMT		0x0002
82#define TYPE50_MEB3_FMT		0x0003
83#define TYPE50_CRB1_FMT		0x0011
84#define TYPE50_CRB2_FMT		0x0012
85#define TYPE50_CRB3_FMT		0x0013
86
87/* Mod-Exp, with a small modulus */
88struct type50_meb1_msg {
89	struct type50_hdr header;
90	unsigned short	keyblock_type;	/* 0x0001 */
91	unsigned char	reserved[6];
92	unsigned char	exponent[128];
93	unsigned char	modulus[128];
94	unsigned char	message[128];
95} __packed;
96
97/* Mod-Exp, with a large modulus */
98struct type50_meb2_msg {
99	struct type50_hdr header;
100	unsigned short	keyblock_type;	/* 0x0002 */
101	unsigned char	reserved[6];
102	unsigned char	exponent[256];
103	unsigned char	modulus[256];
104	unsigned char	message[256];
105} __packed;
106
107/* Mod-Exp, with a larger modulus */
108struct type50_meb3_msg {
109	struct type50_hdr header;
110	unsigned short	keyblock_type;	/* 0x0003 */
111	unsigned char	reserved[6];
112	unsigned char	exponent[512];
113	unsigned char	modulus[512];
114	unsigned char	message[512];
115} __packed;
116
117/* CRT, with a small modulus */
118struct type50_crb1_msg {
119	struct type50_hdr header;
120	unsigned short	keyblock_type;	/* 0x0011 */
121	unsigned char	reserved[6];
122	unsigned char	p[64];
123	unsigned char	q[64];
124	unsigned char	dp[64];
125	unsigned char	dq[64];
126	unsigned char	u[64];
127	unsigned char	message[128];
128} __packed;
129
130/* CRT, with a large modulus */
131struct type50_crb2_msg {
132	struct type50_hdr header;
133	unsigned short	keyblock_type;	/* 0x0012 */
134	unsigned char	reserved[6];
135	unsigned char	p[128];
136	unsigned char	q[128];
137	unsigned char	dp[128];
138	unsigned char	dq[128];
139	unsigned char	u[128];
140	unsigned char	message[256];
141} __packed;
142
143/* CRT, with a larger modulus */
144struct type50_crb3_msg {
145	struct type50_hdr header;
146	unsigned short	keyblock_type;	/* 0x0013 */
147	unsigned char	reserved[6];
148	unsigned char	p[256];
149	unsigned char	q[256];
150	unsigned char	dp[256];
151	unsigned char	dq[256];
152	unsigned char	u[256];
153	unsigned char	message[512];
154} __packed;
155
156/**
157 * The type 80 response family is associated with a CEX2A card.
158 *
159 * Note that all unsigned char arrays are right-justified and left-padded
160 * with zeroes.
161 *
162 * Note that all reserved fields must be zeroes.
163 */
164
165#define TYPE80_RSP_CODE 0x80
166
167struct type80_hdr {
168	unsigned char	reserved1;
169	unsigned char	type;		/* 0x80 */
170	unsigned short	len;
171	unsigned char	code;		/* 0x00 */
172	unsigned char	reserved2[3];
173	unsigned char	reserved3[8];
174} __packed;
175
176/**
177 * Convert a ICAMEX message to a type50 MEX message.
178 *
179 * @zdev: crypto device pointer
180 * @zreq: crypto request pointer
181 * @mex: pointer to user input data
182 *
183 * Returns 0 on success or -EFAULT.
184 */
185static int ICAMEX_msg_to_type50MEX_msg(struct zcrypt_device *zdev,
186				       struct ap_message *ap_msg,
187				       struct ica_rsa_modexpo *mex)
188{
189	unsigned char *mod, *exp, *inp;
190	int mod_len;
191
192	mod_len = mex->inputdatalength;
193
194	if (mod_len <= 128) {
195		struct type50_meb1_msg *meb1 = ap_msg->message;
196		memset(meb1, 0, sizeof(*meb1));
197		ap_msg->length = sizeof(*meb1);
198		meb1->header.msg_type_code = TYPE50_TYPE_CODE;
199		meb1->header.msg_len = sizeof(*meb1);
200		meb1->keyblock_type = TYPE50_MEB1_FMT;
201		mod = meb1->modulus + sizeof(meb1->modulus) - mod_len;
202		exp = meb1->exponent + sizeof(meb1->exponent) - mod_len;
203		inp = meb1->message + sizeof(meb1->message) - mod_len;
204	} else if (mod_len <= 256) {
205		struct type50_meb2_msg *meb2 = ap_msg->message;
206		memset(meb2, 0, sizeof(*meb2));
207		ap_msg->length = sizeof(*meb2);
208		meb2->header.msg_type_code = TYPE50_TYPE_CODE;
209		meb2->header.msg_len = sizeof(*meb2);
210		meb2->keyblock_type = TYPE50_MEB2_FMT;
211		mod = meb2->modulus + sizeof(meb2->modulus) - mod_len;
212		exp = meb2->exponent + sizeof(meb2->exponent) - mod_len;
213		inp = meb2->message + sizeof(meb2->message) - mod_len;
214	} else {
215		/* mod_len > 256 = 4096 bit RSA Key */
216		struct type50_meb3_msg *meb3 = ap_msg->message;
217		memset(meb3, 0, sizeof(*meb3));
218		ap_msg->length = sizeof(*meb3);
219		meb3->header.msg_type_code = TYPE50_TYPE_CODE;
220		meb3->header.msg_len = sizeof(*meb3);
221		meb3->keyblock_type = TYPE50_MEB3_FMT;
222		mod = meb3->modulus + sizeof(meb3->modulus) - mod_len;
223		exp = meb3->exponent + sizeof(meb3->exponent) - mod_len;
224		inp = meb3->message + sizeof(meb3->message) - mod_len;
225	}
226
227	if (copy_from_user(mod, mex->n_modulus, mod_len) ||
228	    copy_from_user(exp, mex->b_key, mod_len) ||
229	    copy_from_user(inp, mex->inputdata, mod_len))
230		return -EFAULT;
231	return 0;
232}
233
234/**
235 * Convert a ICACRT message to a type50 CRT message.
236 *
237 * @zdev: crypto device pointer
238 * @zreq: crypto request pointer
239 * @crt: pointer to user input data
240 *
241 * Returns 0 on success or -EFAULT.
242 */
243static int ICACRT_msg_to_type50CRT_msg(struct zcrypt_device *zdev,
244				       struct ap_message *ap_msg,
245				       struct ica_rsa_modexpo_crt *crt)
246{
247	int mod_len, short_len;
248	unsigned char *p, *q, *dp, *dq, *u, *inp;
249
250	mod_len = crt->inputdatalength;
251	short_len = mod_len / 2;
252
253	/*
254	 * CEX2A and CEX3A w/o FW update can handle requests up to
255	 * 256 byte modulus (2k keys).
256	 * CEX3A with FW update and CEX4A cards are able to handle
257	 * 512 byte modulus (4k keys).
258	 */
259	if (mod_len <= 128) {		/* up to 1024 bit key size */
260		struct type50_crb1_msg *crb1 = ap_msg->message;
261		memset(crb1, 0, sizeof(*crb1));
262		ap_msg->length = sizeof(*crb1);
263		crb1->header.msg_type_code = TYPE50_TYPE_CODE;
264		crb1->header.msg_len = sizeof(*crb1);
265		crb1->keyblock_type = TYPE50_CRB1_FMT;
266		p = crb1->p + sizeof(crb1->p) - short_len;
267		q = crb1->q + sizeof(crb1->q) - short_len;
268		dp = crb1->dp + sizeof(crb1->dp) - short_len;
269		dq = crb1->dq + sizeof(crb1->dq) - short_len;
270		u = crb1->u + sizeof(crb1->u) - short_len;
271		inp = crb1->message + sizeof(crb1->message) - mod_len;
272	} else if (mod_len <= 256) {	/* up to 2048 bit key size */
273		struct type50_crb2_msg *crb2 = ap_msg->message;
274		memset(crb2, 0, sizeof(*crb2));
275		ap_msg->length = sizeof(*crb2);
276		crb2->header.msg_type_code = TYPE50_TYPE_CODE;
277		crb2->header.msg_len = sizeof(*crb2);
278		crb2->keyblock_type = TYPE50_CRB2_FMT;
279		p = crb2->p + sizeof(crb2->p) - short_len;
280		q = crb2->q + sizeof(crb2->q) - short_len;
281		dp = crb2->dp + sizeof(crb2->dp) - short_len;
282		dq = crb2->dq + sizeof(crb2->dq) - short_len;
283		u = crb2->u + sizeof(crb2->u) - short_len;
284		inp = crb2->message + sizeof(crb2->message) - mod_len;
285	} else if ((mod_len <= 512) &&	/* up to 4096 bit key size */
286		   (zdev->max_mod_size == CEX3A_MAX_MOD_SIZE)) { /* >= CEX3A */
287		struct type50_crb3_msg *crb3 = ap_msg->message;
288		memset(crb3, 0, sizeof(*crb3));
289		ap_msg->length = sizeof(*crb3);
290		crb3->header.msg_type_code = TYPE50_TYPE_CODE;
291		crb3->header.msg_len = sizeof(*crb3);
292		crb3->keyblock_type = TYPE50_CRB3_FMT;
293		p = crb3->p + sizeof(crb3->p) - short_len;
294		q = crb3->q + sizeof(crb3->q) - short_len;
295		dp = crb3->dp + sizeof(crb3->dp) - short_len;
296		dq = crb3->dq + sizeof(crb3->dq) - short_len;
297		u = crb3->u + sizeof(crb3->u) - short_len;
298		inp = crb3->message + sizeof(crb3->message) - mod_len;
299	} else
300		return -EINVAL;
301
302	/*
303	 * correct the offset of p, bp and mult_inv according zcrypt.h
304	 * block size right aligned (skip the first byte)
305	 */
306	if (copy_from_user(p, crt->np_prime + MSGTYPE_ADJUSTMENT, short_len) ||
307	    copy_from_user(q, crt->nq_prime, short_len) ||
308	    copy_from_user(dp, crt->bp_key + MSGTYPE_ADJUSTMENT, short_len) ||
309	    copy_from_user(dq, crt->bq_key, short_len) ||
310	    copy_from_user(u, crt->u_mult_inv + MSGTYPE_ADJUSTMENT, short_len) ||
311	    copy_from_user(inp, crt->inputdata, mod_len))
312		return -EFAULT;
313
314	return 0;
315}
316
317/**
318 * Copy results from a type 80 reply message back to user space.
319 *
320 * @zdev: crypto device pointer
321 * @reply: reply AP message.
322 * @data: pointer to user output data
323 * @length: size of user output data
324 *
325 * Returns 0 on success or -EFAULT.
326 */
327static int convert_type80(struct zcrypt_device *zdev,
328			  struct ap_message *reply,
329			  char __user *outputdata,
330			  unsigned int outputdatalength)
331{
332	struct type80_hdr *t80h = reply->message;
333	unsigned char *data;
334
335	if (t80h->len < sizeof(*t80h) + outputdatalength) {
336		/* The result is too short, the CEX2A card may not do that.. */
337		zdev->online = 0;
338		pr_err("Cryptographic device %x failed and was set offline\n",
339		       zdev->ap_dev->qid);
340		ZCRYPT_DBF_DEV(DBF_ERR, zdev, "dev%04xo%drc%d",
341			       zdev->ap_dev->qid, zdev->online, t80h->code);
342
343		return -EAGAIN;	/* repeat the request on a different device. */
344	}
345	if (zdev->user_space_type == ZCRYPT_CEX2A)
346		BUG_ON(t80h->len > CEX2A_MAX_RESPONSE_SIZE);
347	else
348		BUG_ON(t80h->len > CEX3A_MAX_RESPONSE_SIZE);
349	data = reply->message + t80h->len - outputdatalength;
350	if (copy_to_user(outputdata, data, outputdatalength))
351		return -EFAULT;
352	return 0;
353}
354
355static int convert_response(struct zcrypt_device *zdev,
356			    struct ap_message *reply,
357			    char __user *outputdata,
358			    unsigned int outputdatalength)
359{
360	/* Response type byte is the second byte in the response. */
361	switch (((unsigned char *) reply->message)[1]) {
362	case TYPE82_RSP_CODE:
363	case TYPE88_RSP_CODE:
364		return convert_error(zdev, reply);
365	case TYPE80_RSP_CODE:
366		return convert_type80(zdev, reply,
367				      outputdata, outputdatalength);
368	default: /* Unknown response type, this should NEVER EVER happen */
369		zdev->online = 0;
370		pr_err("Cryptographic device %x failed and was set offline\n",
371		       zdev->ap_dev->qid);
372		ZCRYPT_DBF_DEV(DBF_ERR, zdev, "dev%04xo%dfail",
373			       zdev->ap_dev->qid, zdev->online);
374		return -EAGAIN;	/* repeat the request on a different device. */
375	}
376}
377
378/**
379 * This function is called from the AP bus code after a crypto request
380 * "msg" has finished with the reply message "reply".
381 * It is called from tasklet context.
382 * @ap_dev: pointer to the AP device
383 * @msg: pointer to the AP message
384 * @reply: pointer to the AP reply message
385 */
386static void zcrypt_cex2a_receive(struct ap_device *ap_dev,
387				 struct ap_message *msg,
388				 struct ap_message *reply)
389{
390	static struct error_hdr error_reply = {
391		.type = TYPE82_RSP_CODE,
392		.reply_code = REP82_ERROR_MACHINE_FAILURE,
393	};
394	struct type80_hdr *t80h;
395	int length;
396
397	/* Copy the reply message to the request message buffer. */
398	if (IS_ERR(reply)) {
399		memcpy(msg->message, &error_reply, sizeof(error_reply));
400		goto out;
401	}
402	t80h = reply->message;
403	if (t80h->type == TYPE80_RSP_CODE) {
404		if (ap_dev->device_type == AP_DEVICE_TYPE_CEX2A)
405			length = min_t(int,
406				       CEX2A_MAX_RESPONSE_SIZE, t80h->len);
407		else
408			length = min_t(int,
409				       CEX3A_MAX_RESPONSE_SIZE, t80h->len);
410		memcpy(msg->message, reply->message, length);
411	} else
412		memcpy(msg->message, reply->message, sizeof(error_reply));
413out:
414	complete((struct completion *) msg->private);
415}
416
417static atomic_t zcrypt_step = ATOMIC_INIT(0);
418
419/**
420 * The request distributor calls this function if it picked the CEX2A
421 * device to handle a modexpo request.
422 * @zdev: pointer to zcrypt_device structure that identifies the
423 *	  CEX2A device to the request distributor
424 * @mex: pointer to the modexpo request buffer
425 */
426static long zcrypt_cex2a_modexpo(struct zcrypt_device *zdev,
427				 struct ica_rsa_modexpo *mex)
428{
429	struct ap_message ap_msg;
430	struct completion work;
431	int rc;
432
433	ap_init_message(&ap_msg);
434	if (zdev->user_space_type == ZCRYPT_CEX2A)
435		ap_msg.message = kmalloc(MSGTYPE50_CRB2_MAX_MSG_SIZE,
436					 GFP_KERNEL);
437	else
438		ap_msg.message = kmalloc(MSGTYPE50_CRB3_MAX_MSG_SIZE,
439					 GFP_KERNEL);
440	if (!ap_msg.message)
441		return -ENOMEM;
442	ap_msg.receive = zcrypt_cex2a_receive;
443	ap_msg.psmid = (((unsigned long long) current->pid) << 32) +
444				atomic_inc_return(&zcrypt_step);
445	ap_msg.private = &work;
446	rc = ICAMEX_msg_to_type50MEX_msg(zdev, &ap_msg, mex);
447	if (rc)
448		goto out_free;
449	init_completion(&work);
450	ap_queue_message(zdev->ap_dev, &ap_msg);
451	rc = wait_for_completion_interruptible(&work);
452	if (rc == 0)
453		rc = convert_response(zdev, &ap_msg, mex->outputdata,
454				      mex->outputdatalength);
455	else
456		/* Signal pending. */
457		ap_cancel_message(zdev->ap_dev, &ap_msg);
458out_free:
459	kfree(ap_msg.message);
460	return rc;
461}
462
463/**
464 * The request distributor calls this function if it picked the CEX2A
465 * device to handle a modexpo_crt request.
466 * @zdev: pointer to zcrypt_device structure that identifies the
467 *	  CEX2A device to the request distributor
468 * @crt: pointer to the modexpoc_crt request buffer
469 */
470static long zcrypt_cex2a_modexpo_crt(struct zcrypt_device *zdev,
471				     struct ica_rsa_modexpo_crt *crt)
472{
473	struct ap_message ap_msg;
474	struct completion work;
475	int rc;
476
477	ap_init_message(&ap_msg);
478	if (zdev->user_space_type == ZCRYPT_CEX2A)
479		ap_msg.message = kmalloc(MSGTYPE50_CRB2_MAX_MSG_SIZE,
480					 GFP_KERNEL);
481	else
482		ap_msg.message = kmalloc(MSGTYPE50_CRB3_MAX_MSG_SIZE,
483					 GFP_KERNEL);
484	if (!ap_msg.message)
485		return -ENOMEM;
486	ap_msg.receive = zcrypt_cex2a_receive;
487	ap_msg.psmid = (((unsigned long long) current->pid) << 32) +
488				atomic_inc_return(&zcrypt_step);
489	ap_msg.private = &work;
490	rc = ICACRT_msg_to_type50CRT_msg(zdev, &ap_msg, crt);
491	if (rc)
492		goto out_free;
493	init_completion(&work);
494	ap_queue_message(zdev->ap_dev, &ap_msg);
495	rc = wait_for_completion_interruptible(&work);
496	if (rc == 0)
497		rc = convert_response(zdev, &ap_msg, crt->outputdata,
498				      crt->outputdatalength);
499	else
500		/* Signal pending. */
501		ap_cancel_message(zdev->ap_dev, &ap_msg);
502out_free:
503	kfree(ap_msg.message);
504	return rc;
505}
506
507/**
508 * The crypto operations for message type 50.
509 */
510static struct zcrypt_ops zcrypt_msgtype50_ops = {
511	.rsa_modexpo = zcrypt_cex2a_modexpo,
512	.rsa_modexpo_crt = zcrypt_cex2a_modexpo_crt,
513	.owner = THIS_MODULE,
514	.variant = MSGTYPE50_VARIANT_DEFAULT,
515};
516
517int __init zcrypt_msgtype50_init(void)
518{
519	zcrypt_msgtype_register(&zcrypt_msgtype50_ops);
520	return 0;
521}
522
523void __exit zcrypt_msgtype50_exit(void)
524{
525	zcrypt_msgtype_unregister(&zcrypt_msgtype50_ops);
526}
527
528module_init(zcrypt_msgtype50_init);
529module_exit(zcrypt_msgtype50_exit);
530