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