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 <linux/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      512     /* 4096 bits    */
  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_RESPONSE_SIZE 0x210   /* 512 bit modulus
  53                                          * (max outputdatalength) +
  54                                          * type80_hdr*/
  55 #define CEX3A_MAX_MESSAGE_SIZE  sizeof(struct type50_crb3_msg)
  56
  57 #define CEX2A_CLEANUP_TIME      (15*HZ)
  58 #define CEX3A_CLEANUP_TIME      CEX2A_CLEANUP_TIME
  59
  60 static struct ap_device_id zcrypt_cex2a_ids[] = {
  61         { AP_DEVICE(AP_DEVICE_TYPE_CEX2A) },
  62         { AP_DEVICE(AP_DEVICE_TYPE_CEX3A) },
  63         { /* end of list */ },
  64 };
  65
  66 #ifndef CONFIG_ZCRYPT_MONOLITHIC
  67 MODULE_DEVICE_TABLE(ap, zcrypt_cex2a_ids);
  68 MODULE_AUTHOR("IBM Corporation");
  69 MODULE_DESCRIPTION("CEX2A Cryptographic Coprocessor device driver, "
  70                    "Copyright 2001, 2006 IBM Corporation");
  71 MODULE_LICENSE("GPL");
  72 #endif
  73
  74 static int zcrypt_cex2a_probe(struct ap_device *ap_dev);
  75 static void zcrypt_cex2a_remove(struct ap_device *ap_dev);
  76 static void zcrypt_cex2a_receive(struct ap_device *, struct ap_message *,
  77                                  struct ap_message *);
  78
  79 static struct ap_driver zcrypt_cex2a_driver = {
  80         .probe = zcrypt_cex2a_probe,
  81         .remove = zcrypt_cex2a_remove,
  82         .receive = zcrypt_cex2a_receive,
  83         .ids = zcrypt_cex2a_ids,
  84         .request_timeout = CEX2A_CLEANUP_TIME,
  85 };
  86
  87 /**
  88  * Convert a ICAMEX message to a type50 MEX message.
  89  *
  90  * @zdev: crypto device pointer
  91  * @zreq: crypto request pointer
  92  * @mex: pointer to user input data
  93  *
  94  * Returns 0 on success or -EFAULT.
  95  */
  96 static int ICAMEX_msg_to_type50MEX_msg(struct zcrypt_device *zdev,
  97                                        struct ap_message *ap_msg,
  98                                        struct ica_rsa_modexpo *mex)
  99 {
 100         unsigned char *mod, *exp, *inp;
 101         int mod_len;
 102
 103         mod_len = mex->inputdatalength;
 104
 105         if (mod_len <= 128) {
 106                 struct type50_meb1_msg *meb1 = ap_msg->message;
 107                 memset(meb1, 0, sizeof(*meb1));
 108                 ap_msg->length = sizeof(*meb1);
 109                 meb1->header.msg_type_code = TYPE50_TYPE_CODE;
 110                 meb1->header.msg_len = sizeof(*meb1);
 111                 meb1->keyblock_type = TYPE50_MEB1_FMT;
 112                 mod = meb1->modulus + sizeof(meb1->modulus) - mod_len;
 113                 exp = meb1->exponent + sizeof(meb1->exponent) - mod_len;
 114                 inp = meb1->message + sizeof(meb1->message) - mod_len;
 115         } else if (mod_len <= 256) {
 116                 struct type50_meb2_msg *meb2 = ap_msg->message;
 117                 memset(meb2, 0, sizeof(*meb2));
 118                 ap_msg->length = sizeof(*meb2);
 119                 meb2->header.msg_type_code = TYPE50_TYPE_CODE;
 120                 meb2->header.msg_len = sizeof(*meb2);
 121                 meb2->keyblock_type = TYPE50_MEB2_FMT;
 122                 mod = meb2->modulus + sizeof(meb2->modulus) - mod_len;
 123                 exp = meb2->exponent + sizeof(meb2->exponent) - mod_len;
 124                 inp = meb2->message + sizeof(meb2->message) - mod_len;
 125         } else {
 126                 /* mod_len > 256 = 4096 bit RSA Key */
 127                 struct type50_meb3_msg *meb3 = ap_msg->message;
 128                 memset(meb3, 0, sizeof(*meb3));
 129                 ap_msg->length = sizeof(*meb3);
 130                 meb3->header.msg_type_code = TYPE50_TYPE_CODE;
 131                 meb3->header.msg_len = sizeof(*meb3);
 132                 meb3->keyblock_type = TYPE50_MEB3_FMT;
 133                 mod = meb3->modulus + sizeof(meb3->modulus) - mod_len;
 134                 exp = meb3->exponent + sizeof(meb3->exponent) - mod_len;
 135                 inp = meb3->message + sizeof(meb3->message) - mod_len;
 136         }
 137
 138         if (copy_from_user(mod, mex->n_modulus, mod_len) ||
 139             copy_from_user(exp, mex->b_key, mod_len) ||
 140             copy_from_user(inp, mex->inputdata, mod_len))
 141                 return -EFAULT;
 142         return 0;
 143 }
 144
 145 /**
 146  * Convert a ICACRT message to a type50 CRT message.
 147  *
 148  * @zdev: crypto device pointer
 149  * @zreq: crypto request pointer
 150  * @crt: pointer to user input data
 151  *
 152  * Returns 0 on success or -EFAULT.
 153  */
 154 static int ICACRT_msg_to_type50CRT_msg(struct zcrypt_device *zdev,
 155                                        struct ap_message *ap_msg,
 156                                        struct ica_rsa_modexpo_crt *crt)
 157 {
 158         int mod_len, short_len, long_len, long_offset, limit;
 159         unsigned char *p, *q, *dp, *dq, *u, *inp;
 160
 161         mod_len = crt->inputdatalength;
 162         short_len = mod_len / 2;
 163         long_len = mod_len / 2 + 8;
 164
 165         /*
 166          * CEX2A cannot handle p, dp, or U > 128 bytes.
 167          * If we have one of these, we need to do extra checking.
 168          * For CEX3A the limit is 256 bytes.
 169          */
 170         if (zdev->max_mod_size == CEX3A_MAX_MOD_SIZE)
 171                 limit = 256;
 172         else
 173                 limit = 128;
 174
 175         if (long_len > limit) {
 176                 /*
 177                  * zcrypt_rsa_crt already checked for the leading
 178                  * zeroes of np_prime, bp_key and u_mult_inc.
 179                  */
 180                 long_offset = long_len - limit;
 181                 long_len = limit;
 182         } else
 183                 long_offset = 0;
 184
 185         /*
 186          * Instead of doing extra work for p, dp, U > 64 bytes, we'll just use
 187          * the larger message structure.
 188          */
 189         if (long_len <= 64) {
 190                 struct type50_crb1_msg *crb1 = ap_msg->message;
 191                 memset(crb1, 0, sizeof(*crb1));
 192                 ap_msg->length = sizeof(*crb1);
 193                 crb1->header.msg_type_code = TYPE50_TYPE_CODE;
 194                 crb1->header.msg_len = sizeof(*crb1);
 195                 crb1->keyblock_type = TYPE50_CRB1_FMT;
 196                 p = crb1->p + sizeof(crb1->p) - long_len;
 197                 q = crb1->q + sizeof(crb1->q) - short_len;
 198                 dp = crb1->dp + sizeof(crb1->dp) - long_len;
 199                 dq = crb1->dq + sizeof(crb1->dq) - short_len;
 200                 u = crb1->u + sizeof(crb1->u) - long_len;
 201                 inp = crb1->message + sizeof(crb1->message) - mod_len;
 202         } else if (long_len <= 128) {
 203                 struct type50_crb2_msg *crb2 = ap_msg->message;
 204                 memset(crb2, 0, sizeof(*crb2));
 205                 ap_msg->length = sizeof(*crb2);
 206                 crb2->header.msg_type_code = TYPE50_TYPE_CODE;
 207                 crb2->header.msg_len = sizeof(*crb2);
 208                 crb2->keyblock_type = TYPE50_CRB2_FMT;
 209                 p = crb2->p + sizeof(crb2->p) - long_len;
 210                 q = crb2->q + sizeof(crb2->q) - short_len;
 211                 dp = crb2->dp + sizeof(crb2->dp) - long_len;
 212                 dq = crb2->dq + sizeof(crb2->dq) - short_len;
 213                 u = crb2->u + sizeof(crb2->u) - long_len;
 214                 inp = crb2->message + sizeof(crb2->message) - mod_len;
 215         } else {
 216                 /* long_len >= 256 */
 217                 struct type50_crb3_msg *crb3 = ap_msg->message;
 218                 memset(crb3, 0, sizeof(*crb3));
 219                 ap_msg->length = sizeof(*crb3);
 220                 crb3->header.msg_type_code = TYPE50_TYPE_CODE;
 221                 crb3->header.msg_len = sizeof(*crb3);
 222                 crb3->keyblock_type = TYPE50_CRB3_FMT;
 223                 p = crb3->p + sizeof(crb3->p) - long_len;
 224                 q = crb3->q + sizeof(crb3->q) - short_len;
 225                 dp = crb3->dp + sizeof(crb3->dp) - long_len;
 226                 dq = crb3->dq + sizeof(crb3->dq) - short_len;
 227                 u = crb3->u + sizeof(crb3->u) - long_len;
 228                 inp = crb3->message + sizeof(crb3->message) - mod_len;
 229         }
 230
 231         if (copy_from_user(p, crt->np_prime + long_offset, long_len) ||
 232             copy_from_user(q, crt->nq_prime, short_len) ||
 233             copy_from_user(dp, crt->bp_key + long_offset, long_len) ||
 234             copy_from_user(dq, crt->bq_key, short_len) ||
 235             copy_from_user(u, crt->u_mult_inv + long_offset, long_len) ||
 236             copy_from_user(inp, crt->inputdata, mod_len))
 237                 return -EFAULT;
 238
 239         return 0;
 240 }
 241
 242 /**
 243  * Copy results from a type 80 reply message back to user space.
 244  *
 245  * @zdev: crypto device pointer
 246  * @reply: reply AP message.
 247  * @data: pointer to user output data
 248  * @length: size of user output data
 249  *
 250  * Returns 0 on success or -EFAULT.
 251  */
 252 static int convert_type80(struct zcrypt_device *zdev,
 253                           struct ap_message *reply,
 254                           char __user *outputdata,
 255                           unsigned int outputdatalength)
 256 {
 257         struct type80_hdr *t80h = reply->message;
 258         unsigned char *data;
 259
 260         if (t80h->len < sizeof(*t80h) + outputdatalength) {
 261                 /* The result is too short, the CEX2A card may not do that.. */
 262                 zdev->online = 0;
 263                 return -EAGAIN; /* repeat the request on a different device. */
 264         }
 265         if (zdev->user_space_type == ZCRYPT_CEX2A)
 266                 BUG_ON(t80h->len > CEX2A_MAX_RESPONSE_SIZE);
 267         else
 268                 BUG_ON(t80h->len > CEX3A_MAX_RESPONSE_SIZE);
 269         data = reply->message + t80h->len - outputdatalength;
 270         if (copy_to_user(outputdata, data, outputdatalength))
 271                 return -EFAULT;
 272         return 0;
 273 }
 274
 275 static int convert_response(struct zcrypt_device *zdev,
 276                             struct ap_message *reply,
 277                             char __user *outputdata,
 278                             unsigned int outputdatalength)
 279 {
 280         /* Response type byte is the second byte in the response. */
 281         switch (((unsigned char *) reply->message)[1]) {
 282         case TYPE82_RSP_CODE:
 283         case TYPE88_RSP_CODE:
 284                 return convert_error(zdev, reply);
 285         case TYPE80_RSP_CODE:
 286                 return convert_type80(zdev, reply,
 287                                       outputdata, outputdatalength);
 288         default: /* Unknown response type, this should NEVER EVER happen */
 289                 zdev->online = 0;
 290                 return -EAGAIN; /* repeat the request on a different device. */
 291         }
 292 }
 293
 294 /**
 295  * This function is called from the AP bus code after a crypto request
 296  * "msg" has finished with the reply message "reply".
 297  * It is called from tasklet context.
 298  * @ap_dev: pointer to the AP device
 299  * @msg: pointer to the AP message
 300  * @reply: pointer to the AP reply message
 301  */
 302 static void zcrypt_cex2a_receive(struct ap_device *ap_dev,
 303                                  struct ap_message *msg,
 304                                  struct ap_message *reply)
 305 {
 306         static struct error_hdr error_reply = {
 307                 .type = TYPE82_RSP_CODE,
 308                 .reply_code = REP82_ERROR_MACHINE_FAILURE,
 309         };
 310         struct type80_hdr *t80h;
 311         int length;
 312
 313         /* Copy the reply message to the request message buffer. */
 314         if (IS_ERR(reply)) {
 315                 memcpy(msg->message, &error_reply, sizeof(error_reply));
 316                 goto out;
 317         }
 318         t80h = reply->message;
 319         if (t80h->type == TYPE80_RSP_CODE) {
 320                 if (ap_dev->device_type == AP_DEVICE_TYPE_CEX2A)
 321                         length = min(CEX2A_MAX_RESPONSE_SIZE, (int) t80h->len);
 322                 else
 323                         length = min(CEX3A_MAX_RESPONSE_SIZE, (int) t80h->len);
 324                 memcpy(msg->message, reply->message, length);
 325         } else
 326                 memcpy(msg->message, reply->message, sizeof error_reply);
 327 out:
 328         complete((struct completion *) msg->private);
 329 }
 330
 331 static atomic_t zcrypt_step = ATOMIC_INIT(0);
 332
 333 /**
 334  * The request distributor calls this function if it picked the CEX2A
 335  * device to handle a modexpo request.
 336  * @zdev: pointer to zcrypt_device structure that identifies the
 337  *        CEX2A device to the request distributor
 338  * @mex: pointer to the modexpo request buffer
 339  */
 340 static long zcrypt_cex2a_modexpo(struct zcrypt_device *zdev,
 341                                  struct ica_rsa_modexpo *mex)
 342 {
 343         struct ap_message ap_msg;
 344         struct completion work;
 345         int rc;
 346
 347         ap_init_message(&ap_msg);
 348         if (zdev->user_space_type == ZCRYPT_CEX2A)
 349                 ap_msg.message = kmalloc(CEX2A_MAX_MESSAGE_SIZE, GFP_KERNEL);
 350         else
 351                 ap_msg.message = kmalloc(CEX3A_MAX_MESSAGE_SIZE, GFP_KERNEL);
 352         if (!ap_msg.message)
 353                 return -ENOMEM;
 354         ap_msg.psmid = (((unsigned long long) current->pid) << 32) +
 355                                 atomic_inc_return(&zcrypt_step);
 356         ap_msg.private = &work;
 357         rc = ICAMEX_msg_to_type50MEX_msg(zdev, &ap_msg, mex);
 358         if (rc)
 359                 goto out_free;
 360         init_completion(&work);
 361         ap_queue_message(zdev->ap_dev, &ap_msg);
 362         rc = wait_for_completion_interruptible(&work);
 363         if (rc == 0)
 364                 rc = convert_response(zdev, &ap_msg, mex->outputdata,
 365                                       mex->outputdatalength);
 366         else
 367                 /* Signal pending. */
 368                 ap_cancel_message(zdev->ap_dev, &ap_msg);
 369 out_free:
 370         kfree(ap_msg.message);
 371         return rc;
 372 }
 373
 374 /**
 375  * The request distributor calls this function if it picked the CEX2A
 376  * device to handle a modexpo_crt request.
 377  * @zdev: pointer to zcrypt_device structure that identifies the
 378  *        CEX2A device to the request distributor
 379  * @crt: pointer to the modexpoc_crt request buffer
 380  */
 381 static long zcrypt_cex2a_modexpo_crt(struct zcrypt_device *zdev,
 382                                      struct ica_rsa_modexpo_crt *crt)
 383 {
 384         struct ap_message ap_msg;
 385         struct completion work;
 386         int rc;
 387
 388         ap_init_message(&ap_msg);
 389         if (zdev->user_space_type == ZCRYPT_CEX2A)
 390                 ap_msg.message = kmalloc(CEX2A_MAX_MESSAGE_SIZE, GFP_KERNEL);
 391         else
 392                 ap_msg.message = kmalloc(CEX3A_MAX_MESSAGE_SIZE, GFP_KERNEL);
 393         if (!ap_msg.message)
 394                 return -ENOMEM;
 395         ap_msg.psmid = (((unsigned long long) current->pid) << 32) +
 396                                 atomic_inc_return(&zcrypt_step);
 397         ap_msg.private = &work;
 398         rc = ICACRT_msg_to_type50CRT_msg(zdev, &ap_msg, crt);
 399         if (rc)
 400                 goto out_free;
 401         init_completion(&work);
 402         ap_queue_message(zdev->ap_dev, &ap_msg);
 403         rc = wait_for_completion_interruptible(&work);
 404         if (rc == 0)
 405                 rc = convert_response(zdev, &ap_msg, crt->outputdata,
 406                                       crt->outputdatalength);
 407         else
 408                 /* Signal pending. */
 409                 ap_cancel_message(zdev->ap_dev, &ap_msg);
 410 out_free:
 411         kfree(ap_msg.message);
 412         return rc;
 413 }
 414
 415 /**
 416  * The crypto operations for a CEX2A card.
 417  */
 418 static struct zcrypt_ops zcrypt_cex2a_ops = {
 419         .rsa_modexpo = zcrypt_cex2a_modexpo,
 420         .rsa_modexpo_crt = zcrypt_cex2a_modexpo_crt,
 421 };
 422
 423 /**
 424  * Probe function for CEX2A cards. It always accepts the AP device
 425  * since the bus_match already checked the hardware type.
 426  * @ap_dev: pointer to the AP device.
 427  */
 428 static int zcrypt_cex2a_probe(struct ap_device *ap_dev)
 429 {
 430         struct zcrypt_device *zdev = NULL;
 431         int rc = 0;
 432
 433         switch (ap_dev->device_type) {
 434         case AP_DEVICE_TYPE_CEX2A:
 435                 zdev = zcrypt_device_alloc(CEX2A_MAX_RESPONSE_SIZE);
 436                 if (!zdev)
 437                         return -ENOMEM;
 438                 zdev->user_space_type = ZCRYPT_CEX2A;
 439                 zdev->type_string = "CEX2A";
 440                 zdev->min_mod_size = CEX2A_MIN_MOD_SIZE;
 441                 zdev->max_mod_size = CEX2A_MAX_MOD_SIZE;
 442                 zdev->short_crt = 1;
 443                 zdev->speed_rating = CEX2A_SPEED_RATING;
 444                 zdev->max_exp_bit_length = CEX2A_MAX_MOD_SIZE;
 445                 break;
 446         case AP_DEVICE_TYPE_CEX3A:
 447                 zdev = zcrypt_device_alloc(CEX3A_MAX_RESPONSE_SIZE);
 448                 if (!zdev)
 449                         return -ENOMEM;
 450                 zdev->user_space_type = ZCRYPT_CEX3A;
 451                 zdev->type_string = "CEX3A";
 452                 zdev->min_mod_size = CEX2A_MIN_MOD_SIZE;
 453                 zdev->max_mod_size = CEX2A_MAX_MOD_SIZE;
 454                 zdev->max_exp_bit_length = CEX2A_MAX_MOD_SIZE;
 455                 if (ap_4096_commands_available(ap_dev->qid)) {
 456                         zdev->max_mod_size = CEX3A_MAX_MOD_SIZE;
 457                         zdev->max_exp_bit_length = CEX3A_MAX_MOD_SIZE;
 458                 }
 459                 zdev->short_crt = 1;
 460                 zdev->speed_rating = CEX3A_SPEED_RATING;
 461                 break;
 462         }
 463         if (zdev != NULL) {
 464                 zdev->ap_dev = ap_dev;
 465                 zdev->ops = &zcrypt_cex2a_ops;
 466                 zdev->online = 1;
 467                 ap_dev->reply = &zdev->reply;
 468                 ap_dev->private = zdev;
 469                 rc = zcrypt_device_register(zdev);
 470         }
 471         if (rc) {
 472                 ap_dev->private = NULL;
 473                 zcrypt_device_free(zdev);
 474         }
 475         return rc;
 476 }
 477
 478 /**
 479  * This is called to remove the extended CEX2A driver information
 480  * if an AP device is removed.
 481  */
 482 static void zcrypt_cex2a_remove(struct ap_device *ap_dev)
 483 {
 484         struct zcrypt_device *zdev = ap_dev->private;
 485
 486         zcrypt_device_unregister(zdev);
 487 }
 488
 489 int __init zcrypt_cex2a_init(void)
 490 {
 491         return ap_driver_register(&zcrypt_cex2a_driver, THIS_MODULE, "cex2a");
 492 }
 493
 494 void __exit zcrypt_cex2a_exit(void)
 495 {
 496         ap_driver_unregister(&zcrypt_cex2a_driver);
 497 }
 498
 499 #ifndef CONFIG_ZCRYPT_MONOLITHIC
 500 module_init(zcrypt_cex2a_init);
 501 module_exit(zcrypt_cex2a_exit);
 502 #endif