drivers/s390/crypto/zcrypt_cex2a.c

   1 /*
   2  *  linux/drivers/s390/crypto/zcrypt_cex2a.c
   3  *
   4  *  zcrypt 2.1.0
   5  *
   6  *  Copyright (C)  2001, 2006 IBM Corporation
   7  *  Author(s): Robert Burroughs
   8  *             Eric Rossman (edrossma@us.ibm.com)
   9  *
  10  *  Hotplug & misc device support: Jochen Roehrig (roehrig@de.ibm.com)
  11  *  Major cleanup & driver split: Martin Schwidefsky <schwidefsky@de.ibm.com>
  12  *                                Ralph Wuerthner <rwuerthn@de.ibm.com>
  13  *
  14  * This program is free software; you can redistribute it and/or modify
  15  * it under the terms of the GNU General Public License as published by
  16  * the Free Software Foundation; either version 2, or (at your option)
  17  * any later version.
  18  *
  19  * This program is distributed in the hope that it will be useful,
  20  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  21  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  22  * GNU General Public License for more details.
  23  *
  24  * You should have received a copy of the GNU General Public License
  25  * along with this program; if not, write to the Free Software
  26  * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  27  */
  28
  29 #include <linux/module.h>
  30 #include <linux/slab.h>
  31 #include <linux/init.h>
  32 #include <linux/err.h>
  33 #include <asm/atomic.h>
  34 #include <asm/uaccess.h>
  35
  36 #include "ap_bus.h"
  37 #include "zcrypt_api.h"
  38 #include "zcrypt_error.h"
  39 #include "zcrypt_cex2a.h"
  40
  41 #define CEX2A_MIN_MOD_SIZE        1     /*    8 bits    */
  42 #define CEX2A_MAX_MOD_SIZE      256     /* 2048 bits    */
  43 #define CEX3A_MIN_MOD_SIZE      CEX2A_MIN_MOD_SIZE
  44 #define CEX3A_MAX_MOD_SIZE      CEX2A_MAX_MOD_SIZE
  45
  46 #define CEX2A_SPEED_RATING      970
  47 #define CEX3A_SPEED_RATING      900 /* Fixme: Needs finetuning */
  48
  49 #define CEX2A_MAX_MESSAGE_SIZE  0x390   /* sizeof(struct type50_crb2_msg)    */
  50 #define CEX2A_MAX_RESPONSE_SIZE 0x110   /* max outputdatalength + type80_hdr */
  51
  52 #define CEX3A_MAX_MESSAGE_SIZE  CEX2A_MAX_MESSAGE_SIZE
  53 #define CEX3A_MAX_RESPONSE_SIZE CEX2A_MAX_RESPONSE_SIZE
  54
  55 #define CEX2A_CLEANUP_TIME      (15*HZ)
  56 #define CEX3A_CLEANUP_TIME      CEX2A_CLEANUP_TIME
  57
  58 static struct ap_device_id zcrypt_cex2a_ids[] = {
  59         { AP_DEVICE(AP_DEVICE_TYPE_CEX2A) },
  60         { AP_DEVICE(AP_DEVICE_TYPE_CEX3A) },
  61         { /* end of list */ },
  62 };
  63
  64 #ifndef CONFIG_ZCRYPT_MONOLITHIC
  65 MODULE_DEVICE_TABLE(ap, zcrypt_cex2a_ids);
  66 MODULE_AUTHOR("IBM Corporation");
  67 MODULE_DESCRIPTION("CEX2A Cryptographic Coprocessor device driver, "
  68                    "Copyright 2001, 2006 IBM Corporation");
  69 MODULE_LICENSE("GPL");
  70 #endif
  71
  72 static int zcrypt_cex2a_probe(struct ap_device *ap_dev);
  73 static void zcrypt_cex2a_remove(struct ap_device *ap_dev);
  74 static void zcrypt_cex2a_receive(struct ap_device *, struct ap_message *,
  75                                  struct ap_message *);
  76
  77 static struct ap_driver zcrypt_cex2a_driver = {
  78         .probe = zcrypt_cex2a_probe,
  79         .remove = zcrypt_cex2a_remove,
  80         .receive = zcrypt_cex2a_receive,
  81         .ids = zcrypt_cex2a_ids,
  82         .request_timeout = CEX2A_CLEANUP_TIME,
  83 };
  84
  85 /**
  86  * Convert a ICAMEX message to a type50 MEX message.
  87  *
  88  * @zdev: crypto device pointer
  89  * @zreq: crypto request pointer
  90  * @mex: pointer to user input data
  91  *
  92  * Returns 0 on success or -EFAULT.
  93  */
  94 static int ICAMEX_msg_to_type50MEX_msg(struct zcrypt_device *zdev,
  95                                        struct ap_message *ap_msg,
  96                                        struct ica_rsa_modexpo *mex)
  97 {
  98         unsigned char *mod, *exp, *inp;
  99         int mod_len;
 100
 101         mod_len = mex->inputdatalength;
 102
 103         if (mod_len <= 128) {
 104                 struct type50_meb1_msg *meb1 = ap_msg->message;
 105                 memset(meb1, 0, sizeof(*meb1));
 106                 ap_msg->length = sizeof(*meb1);
 107                 meb1->header.msg_type_code = TYPE50_TYPE_CODE;
 108                 meb1->header.msg_len = sizeof(*meb1);
 109                 meb1->keyblock_type = TYPE50_MEB1_FMT;
 110                 mod = meb1->modulus + sizeof(meb1->modulus) - mod_len;
 111                 exp = meb1->exponent + sizeof(meb1->exponent) - mod_len;
 112                 inp = meb1->message + sizeof(meb1->message) - mod_len;
 113         } else {
 114                 struct type50_meb2_msg *meb2 = ap_msg->message;
 115                 memset(meb2, 0, sizeof(*meb2));
 116                 ap_msg->length = sizeof(*meb2);
 117                 meb2->header.msg_type_code = TYPE50_TYPE_CODE;
 118                 meb2->header.msg_len = sizeof(*meb2);
 119                 meb2->keyblock_type = TYPE50_MEB2_FMT;
 120                 mod = meb2->modulus + sizeof(meb2->modulus) - mod_len;
 121                 exp = meb2->exponent + sizeof(meb2->exponent) - mod_len;
 122                 inp = meb2->message + sizeof(meb2->message) - mod_len;
 123         }
 124
 125         if (copy_from_user(mod, mex->n_modulus, mod_len) ||
 126             copy_from_user(exp, mex->b_key, mod_len) ||
 127             copy_from_user(inp, mex->inputdata, mod_len))
 128                 return -EFAULT;
 129         return 0;
 130 }
 131
 132 /**
 133  * Convert a ICACRT message to a type50 CRT message.
 134  *
 135  * @zdev: crypto device pointer
 136  * @zreq: crypto request pointer
 137  * @crt: pointer to user input data
 138  *
 139  * Returns 0 on success or -EFAULT.
 140  */
 141 static int ICACRT_msg_to_type50CRT_msg(struct zcrypt_device *zdev,
 142                                        struct ap_message *ap_msg,
 143                                        struct ica_rsa_modexpo_crt *crt)
 144 {
 145         int mod_len, short_len, long_len, long_offset;
 146         unsigned char *p, *q, *dp, *dq, *u, *inp;
 147
 148         mod_len = crt->inputdatalength;
 149         short_len = mod_len / 2;
 150         long_len = mod_len / 2 + 8;
 151
 152         /*
 153          * CEX2A cannot handle p, dp, or U > 128 bytes.
 154          * If we have one of these, we need to do extra checking.
 155          */
 156         if (long_len > 128) {
 157                 /*
 158                  * zcrypt_rsa_crt already checked for the leading
 159                  * zeroes of np_prime, bp_key and u_mult_inc.
 160                  */
 161                 long_offset = long_len - 128;
 162                 long_len = 128;
 163         } else
 164                 long_offset = 0;
 165
 166         /*
 167          * Instead of doing extra work for p, dp, U > 64 bytes, we'll just use
 168          * the larger message structure.
 169          */
 170         if (long_len <= 64) {
 171                 struct type50_crb1_msg *crb1 = ap_msg->message;
 172                 memset(crb1, 0, sizeof(*crb1));
 173                 ap_msg->length = sizeof(*crb1);
 174                 crb1->header.msg_type_code = TYPE50_TYPE_CODE;
 175                 crb1->header.msg_len = sizeof(*crb1);
 176                 crb1->keyblock_type = TYPE50_CRB1_FMT;
 177                 p = crb1->p + sizeof(crb1->p) - long_len;
 178                 q = crb1->q + sizeof(crb1->q) - short_len;
 179                 dp = crb1->dp + sizeof(crb1->dp) - long_len;
 180                 dq = crb1->dq + sizeof(crb1->dq) - short_len;
 181                 u = crb1->u + sizeof(crb1->u) - long_len;
 182                 inp = crb1->message + sizeof(crb1->message) - mod_len;
 183         } else {
 184                 struct type50_crb2_msg *crb2 = ap_msg->message;
 185                 memset(crb2, 0, sizeof(*crb2));
 186                 ap_msg->length = sizeof(*crb2);
 187                 crb2->header.msg_type_code = TYPE50_TYPE_CODE;
 188                 crb2->header.msg_len = sizeof(*crb2);
 189                 crb2->keyblock_type = TYPE50_CRB2_FMT;
 190                 p = crb2->p + sizeof(crb2->p) - long_len;
 191                 q = crb2->q + sizeof(crb2->q) - short_len;
 192                 dp = crb2->dp + sizeof(crb2->dp) - long_len;
 193                 dq = crb2->dq + sizeof(crb2->dq) - short_len;
 194                 u = crb2->u + sizeof(crb2->u) - long_len;
 195                 inp = crb2->message + sizeof(crb2->message) - mod_len;
 196         }
 197
 198         if (copy_from_user(p, crt->np_prime + long_offset, long_len) ||
 199             copy_from_user(q, crt->nq_prime, short_len) ||
 200             copy_from_user(dp, crt->bp_key + long_offset, long_len) ||
 201             copy_from_user(dq, crt->bq_key, short_len) ||
 202             copy_from_user(u, crt->u_mult_inv + long_offset, long_len) ||
 203             copy_from_user(inp, crt->inputdata, mod_len))
 204                 return -EFAULT;
 205
 206
 207         return 0;
 208 }
 209
 210 /**
 211  * Copy results from a type 80 reply message back to user space.
 212  *
 213  * @zdev: crypto device pointer
 214  * @reply: reply AP message.
 215  * @data: pointer to user output data
 216  * @length: size of user output data
 217  *
 218  * Returns 0 on success or -EFAULT.
 219  */
 220 static int convert_type80(struct zcrypt_device *zdev,
 221                           struct ap_message *reply,
 222                           char __user *outputdata,
 223                           unsigned int outputdatalength)
 224 {
 225         struct type80_hdr *t80h = reply->message;
 226         unsigned char *data;
 227
 228         if (t80h->len < sizeof(*t80h) + outputdatalength) {
 229                 /* The result is too short, the CEX2A card may not do that.. */
 230                 zdev->online = 0;
 231                 return -EAGAIN; /* repeat the request on a different device. */
 232         }
 233         BUG_ON(t80h->len > CEX2A_MAX_RESPONSE_SIZE);
 234         data = reply->message + t80h->len - outputdatalength;
 235         if (copy_to_user(outputdata, data, outputdatalength))
 236                 return -EFAULT;
 237         return 0;
 238 }
 239
 240 static int convert_response(struct zcrypt_device *zdev,
 241                             struct ap_message *reply,
 242                             char __user *outputdata,
 243                             unsigned int outputdatalength)
 244 {
 245         /* Response type byte is the second byte in the response. */
 246         switch (((unsigned char *) reply->message)[1]) {
 247         case TYPE82_RSP_CODE:
 248         case TYPE88_RSP_CODE:
 249                 return convert_error(zdev, reply);
 250         case TYPE80_RSP_CODE:
 251                 return convert_type80(zdev, reply,
 252                                       outputdata, outputdatalength);
 253         default: /* Unknown response type, this should NEVER EVER happen */
 254                 zdev->online = 0;
 255                 return -EAGAIN; /* repeat the request on a different device. */
 256         }
 257 }
 258
 259 /**
 260  * This function is called from the AP bus code after a crypto request
 261  * "msg" has finished with the reply message "reply".
 262  * It is called from tasklet context.
 263  * @ap_dev: pointer to the AP device
 264  * @msg: pointer to the AP message
 265  * @reply: pointer to the AP reply message
 266  */
 267 static void zcrypt_cex2a_receive(struct ap_device *ap_dev,
 268                                  struct ap_message *msg,
 269                                  struct ap_message *reply)
 270 {
 271         static struct error_hdr error_reply = {
 272                 .type = TYPE82_RSP_CODE,
 273                 .reply_code = REP82_ERROR_MACHINE_FAILURE,
 274         };
 275         struct type80_hdr *t80h;
 276         int length;
 277
 278         /* Copy the reply message to the request message buffer. */
 279         if (IS_ERR(reply)) {
 280                 memcpy(msg->message, &error_reply, sizeof(error_reply));
 281                 goto out;
 282         }
 283         t80h = reply->message;
 284         if (t80h->type == TYPE80_RSP_CODE) {
 285                 length = min(CEX2A_MAX_RESPONSE_SIZE, (int) t80h->len);
 286                 memcpy(msg->message, reply->message, length);
 287         } else
 288                 memcpy(msg->message, reply->message, sizeof error_reply);
 289 out:
 290         complete((struct completion *) msg->private);
 291 }
 292
 293 static atomic_t zcrypt_step = ATOMIC_INIT(0);
 294
 295 /**
 296  * The request distributor calls this function if it picked the CEX2A
 297  * device to handle a modexpo request.
 298  * @zdev: pointer to zcrypt_device structure that identifies the
 299  *        CEX2A device to the request distributor
 300  * @mex: pointer to the modexpo request buffer
 301  */
 302 static long zcrypt_cex2a_modexpo(struct zcrypt_device *zdev,
 303                                  struct ica_rsa_modexpo *mex)
 304 {
 305         struct ap_message ap_msg;
 306         struct completion work;
 307         int rc;
 308
 309         ap_init_message(&ap_msg);
 310         ap_msg.message = kmalloc(CEX2A_MAX_MESSAGE_SIZE, GFP_KERNEL);
 311         if (!ap_msg.message)
 312                 return -ENOMEM;
 313         ap_msg.psmid = (((unsigned long long) current->pid) << 32) +
 314                                 atomic_inc_return(&zcrypt_step);
 315         ap_msg.private = &work;
 316         rc = ICAMEX_msg_to_type50MEX_msg(zdev, &ap_msg, mex);
 317         if (rc)
 318                 goto out_free;
 319         init_completion(&work);
 320         ap_queue_message(zdev->ap_dev, &ap_msg);
 321         rc = wait_for_completion_interruptible(&work);
 322         if (rc == 0)
 323                 rc = convert_response(zdev, &ap_msg, mex->outputdata,
 324                                       mex->outputdatalength);
 325         else
 326                 /* Signal pending. */
 327                 ap_cancel_message(zdev->ap_dev, &ap_msg);
 328 out_free:
 329         kfree(ap_msg.message);
 330         return rc;
 331 }
 332
 333 /**
 334  * The request distributor calls this function if it picked the CEX2A
 335  * device to handle a modexpo_crt request.
 336  * @zdev: pointer to zcrypt_device structure that identifies the
 337  *        CEX2A device to the request distributor
 338  * @crt: pointer to the modexpoc_crt request buffer
 339  */
 340 static long zcrypt_cex2a_modexpo_crt(struct zcrypt_device *zdev,
 341                                      struct ica_rsa_modexpo_crt *crt)
 342 {
 343         struct ap_message ap_msg;
 344         struct completion work;
 345         int rc;
 346
 347         ap_init_message(&ap_msg);
 348         ap_msg.message = kmalloc(CEX2A_MAX_MESSAGE_SIZE, GFP_KERNEL);
 349         if (!ap_msg.message)
 350                 return -ENOMEM;
 351         ap_msg.psmid = (((unsigned long long) current->pid) << 32) +
 352                                 atomic_inc_return(&zcrypt_step);
 353         ap_msg.private = &work;
 354         rc = ICACRT_msg_to_type50CRT_msg(zdev, &ap_msg, crt);
 355         if (rc)
 356                 goto out_free;
 357         init_completion(&work);
 358         ap_queue_message(zdev->ap_dev, &ap_msg);
 359         rc = wait_for_completion_interruptible(&work);
 360         if (rc == 0)
 361                 rc = convert_response(zdev, &ap_msg, crt->outputdata,
 362                                       crt->outputdatalength);
 363         else
 364                 /* Signal pending. */
 365                 ap_cancel_message(zdev->ap_dev, &ap_msg);
 366 out_free:
 367         kfree(ap_msg.message);
 368         return rc;
 369 }
 370
 371 /**
 372  * The crypto operations for a CEX2A card.
 373  */
 374 static struct zcrypt_ops zcrypt_cex2a_ops = {
 375         .rsa_modexpo = zcrypt_cex2a_modexpo,
 376         .rsa_modexpo_crt = zcrypt_cex2a_modexpo_crt,
 377 };
 378
 379 /**
 380  * Probe function for CEX2A cards. It always accepts the AP device
 381  * since the bus_match already checked the hardware type.
 382  * @ap_dev: pointer to the AP device.
 383  */
 384 static int zcrypt_cex2a_probe(struct ap_device *ap_dev)
 385 {
 386         struct zcrypt_device *zdev = NULL;
 387         int rc = 0;
 388
 389         switch (ap_dev->device_type) {
 390         case AP_DEVICE_TYPE_CEX2A:
 391                 zdev = zcrypt_device_alloc(CEX2A_MAX_RESPONSE_SIZE);
 392                 if (!zdev)
 393                         return -ENOMEM;
 394                 zdev->user_space_type = ZCRYPT_CEX2A;
 395                 zdev->type_string = "CEX2A";
 396                 zdev->min_mod_size = CEX2A_MIN_MOD_SIZE;
 397                 zdev->max_mod_size = CEX2A_MAX_MOD_SIZE;
 398                 zdev->short_crt = 1;
 399                 zdev->speed_rating = CEX2A_SPEED_RATING;
 400                 break;
 401         case AP_DEVICE_TYPE_CEX3A:
 402                 zdev = zcrypt_device_alloc(CEX3A_MAX_RESPONSE_SIZE);
 403                 if (!zdev)
 404                         return -ENOMEM;
 405                 zdev->user_space_type = ZCRYPT_CEX3A;
 406                 zdev->type_string = "CEX3A";
 407                 zdev->min_mod_size = CEX3A_MIN_MOD_SIZE;
 408                 zdev->max_mod_size = CEX3A_MAX_MOD_SIZE;
 409                 zdev->short_crt = 1;
 410                 zdev->speed_rating = CEX3A_SPEED_RATING;
 411                 break;
 412         }
 413         if (zdev != NULL) {
 414                 zdev->ap_dev = ap_dev;
 415                 zdev->ops = &zcrypt_cex2a_ops;
 416                 zdev->online = 1;
 417                 ap_dev->reply = &zdev->reply;
 418                 ap_dev->private = zdev;
 419                 rc = zcrypt_device_register(zdev);
 420         }
 421         if (rc) {
 422                 ap_dev->private = NULL;
 423                 zcrypt_device_free(zdev);
 424         }
 425         return rc;
 426 }
 427
 428 /**
 429  * This is called to remove the extended CEX2A driver information
 430  * if an AP device is removed.
 431  */
 432 static void zcrypt_cex2a_remove(struct ap_device *ap_dev)
 433 {
 434         struct zcrypt_device *zdev = ap_dev->private;
 435
 436         zcrypt_device_unregister(zdev);
 437 }
 438
 439 int __init zcrypt_cex2a_init(void)
 440 {
 441         return ap_driver_register(&zcrypt_cex2a_driver, THIS_MODULE, "cex2a");
 442 }
 443
 444 void __exit zcrypt_cex2a_exit(void)
 445 {
 446         ap_driver_unregister(&zcrypt_cex2a_driver);
 447 }
 448
 449 #ifndef CONFIG_ZCRYPT_MONOLITHIC
 450 module_init(zcrypt_cex2a_init);
 451 module_exit(zcrypt_cex2a_exit);
 452 #endif