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
  43 #define CEX2A_SPEED_RATING      970
  44
  45 #define CEX2A_MAX_MESSAGE_SIZE  0x390   /* sizeof(struct type50_crb2_msg)    */
  46 #define CEX2A_MAX_RESPONSE_SIZE 0x110   /* max outputdatalength + type80_hdr */
  47
  48 #define CEX2A_CLEANUP_TIME      (15*HZ)
  49
  50 static struct ap_device_id zcrypt_cex2a_ids[] = {
  51         { AP_DEVICE(AP_DEVICE_TYPE_CEX2A) },
  52         { /* end of list */ },
  53 };
  54
  55 #ifndef CONFIG_ZCRYPT_MONOLITHIC
  56 MODULE_DEVICE_TABLE(ap, zcrypt_cex2a_ids);
  57 MODULE_AUTHOR("IBM Corporation");
  58 MODULE_DESCRIPTION("CEX2A Cryptographic Coprocessor device driver, "
  59                    "Copyright 2001, 2006 IBM Corporation");
  60 MODULE_LICENSE("GPL");
  61 #endif
  62
  63 static int zcrypt_cex2a_probe(struct ap_device *ap_dev);
  64 static void zcrypt_cex2a_remove(struct ap_device *ap_dev);
  65 static void zcrypt_cex2a_receive(struct ap_device *, struct ap_message *,
  66                                  struct ap_message *);
  67
  68 static struct ap_driver zcrypt_cex2a_driver = {
  69         .probe = zcrypt_cex2a_probe,
  70         .remove = zcrypt_cex2a_remove,
  71         .receive = zcrypt_cex2a_receive,
  72         .ids = zcrypt_cex2a_ids,
  73 };
  74
  75 /**
  76  * Convert a ICAMEX message to a type50 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  */
  84 static int ICAMEX_msg_to_type50MEX_msg(struct zcrypt_device *zdev,
  85                                        struct ap_message *ap_msg,
  86                                        struct ica_rsa_modexpo *mex)
  87 {
  88         unsigned char *mod, *exp, *inp;
  89         int mod_len;
  90
  91         mod_len = mex->inputdatalength;
  92
  93         if (mod_len <= 128) {
  94                 struct type50_meb1_msg *meb1 = ap_msg->message;
  95                 memset(meb1, 0, sizeof(*meb1));
  96                 ap_msg->length = sizeof(*meb1);
  97                 meb1->header.msg_type_code = TYPE50_TYPE_CODE;
  98                 meb1->header.msg_len = sizeof(*meb1);
  99                 meb1->keyblock_type = TYPE50_MEB1_FMT;
 100                 mod = meb1->modulus + sizeof(meb1->modulus) - mod_len;
 101                 exp = meb1->exponent + sizeof(meb1->exponent) - mod_len;
 102                 inp = meb1->message + sizeof(meb1->message) - mod_len;
 103         } else {
 104                 struct type50_meb2_msg *meb2 = ap_msg->message;
 105                 memset(meb2, 0, sizeof(*meb2));
 106                 ap_msg->length = sizeof(*meb2);
 107                 meb2->header.msg_type_code = TYPE50_TYPE_CODE;
 108                 meb2->header.msg_len = sizeof(*meb2);
 109                 meb2->keyblock_type = TYPE50_MEB2_FMT;
 110                 mod = meb2->modulus + sizeof(meb2->modulus) - mod_len;
 111                 exp = meb2->exponent + sizeof(meb2->exponent) - mod_len;
 112                 inp = meb2->message + sizeof(meb2->message) - mod_len;
 113         }
 114
 115         if (copy_from_user(mod, mex->n_modulus, mod_len) ||
 116             copy_from_user(exp, mex->b_key, mod_len) ||
 117             copy_from_user(inp, mex->inputdata, mod_len))
 118                 return -EFAULT;
 119         return 0;
 120 }
 121
 122 /**
 123  * Convert a ICACRT message to a type50 CRT message.
 124  *
 125  * @zdev: crypto device pointer
 126  * @zreq: crypto request pointer
 127  * @crt: pointer to user input data
 128  *
 129  * Returns 0 on success or -EFAULT.
 130  */
 131 static int ICACRT_msg_to_type50CRT_msg(struct zcrypt_device *zdev,
 132                                        struct ap_message *ap_msg,
 133                                        struct ica_rsa_modexpo_crt *crt)
 134 {
 135         int mod_len, short_len, long_len, long_offset;
 136         unsigned char *p, *q, *dp, *dq, *u, *inp;
 137
 138         mod_len = crt->inputdatalength;
 139         short_len = mod_len / 2;
 140         long_len = mod_len / 2 + 8;
 141
 142         /*
 143          * CEX2A cannot handle p, dp, or U > 128 bytes.
 144          * If we have one of these, we need to do extra checking.
 145          */
 146         if (long_len > 128) {
 147                 /*
 148                  * zcrypt_rsa_crt already checked for the leading
 149                  * zeroes of np_prime, bp_key and u_mult_inc.
 150                  */
 151                 long_offset = long_len - 128;
 152                 long_len = 128;
 153         } else
 154                 long_offset = 0;
 155
 156         /*
 157          * Instead of doing extra work for p, dp, U > 64 bytes, we'll just use
 158          * the larger message structure.
 159          */
 160         if (long_len <= 64) {
 161                 struct type50_crb1_msg *crb1 = ap_msg->message;
 162                 memset(crb1, 0, sizeof(*crb1));
 163                 ap_msg->length = sizeof(*crb1);
 164                 crb1->header.msg_type_code = TYPE50_TYPE_CODE;
 165                 crb1->header.msg_len = sizeof(*crb1);
 166                 crb1->keyblock_type = TYPE50_CRB1_FMT;
 167                 p = crb1->p + sizeof(crb1->p) - long_len;
 168                 q = crb1->q + sizeof(crb1->q) - short_len;
 169                 dp = crb1->dp + sizeof(crb1->dp) - long_len;
 170                 dq = crb1->dq + sizeof(crb1->dq) - short_len;
 171                 u = crb1->u + sizeof(crb1->u) - long_len;
 172                 inp = crb1->message + sizeof(crb1->message) - mod_len;
 173         } else {
 174                 struct type50_crb2_msg *crb2 = ap_msg->message;
 175                 memset(crb2, 0, sizeof(*crb2));
 176                 ap_msg->length = sizeof(*crb2);
 177                 crb2->header.msg_type_code = TYPE50_TYPE_CODE;
 178                 crb2->header.msg_len = sizeof(*crb2);
 179                 crb2->keyblock_type = TYPE50_CRB2_FMT;
 180                 p = crb2->p + sizeof(crb2->p) - long_len;
 181                 q = crb2->q + sizeof(crb2->q) - short_len;
 182                 dp = crb2->dp + sizeof(crb2->dp) - long_len;
 183                 dq = crb2->dq + sizeof(crb2->dq) - short_len;
 184                 u = crb2->u + sizeof(crb2->u) - long_len;
 185                 inp = crb2->message + sizeof(crb2->message) - mod_len;
 186         }
 187
 188         if (copy_from_user(p, crt->np_prime + long_offset, long_len) ||
 189             copy_from_user(q, crt->nq_prime, short_len) ||
 190             copy_from_user(dp, crt->bp_key + long_offset, long_len) ||
 191             copy_from_user(dq, crt->bq_key, short_len) ||
 192             copy_from_user(u, crt->u_mult_inv + long_offset, long_len) ||
 193             copy_from_user(inp, crt->inputdata, mod_len))
 194                 return -EFAULT;
 195
 196
 197         return 0;
 198 }
 199
 200 /**
 201  * Copy results from a type 80 reply message back to user space.
 202  *
 203  * @zdev: crypto device pointer
 204  * @reply: reply AP message.
 205  * @data: pointer to user output data
 206  * @length: size of user output data
 207  *
 208  * Returns 0 on success or -EFAULT.
 209  */
 210 static int convert_type80(struct zcrypt_device *zdev,
 211                           struct ap_message *reply,
 212                           char __user *outputdata,
 213                           unsigned int outputdatalength)
 214 {
 215         struct type80_hdr *t80h = reply->message;
 216         unsigned char *data;
 217
 218         if (t80h->len < sizeof(*t80h) + outputdatalength) {
 219                 /* The result is too short, the CEX2A card may not do that.. */
 220                 zdev->online = 0;
 221                 return -EAGAIN; /* repeat the request on a different device. */
 222         }
 223         BUG_ON(t80h->len > CEX2A_MAX_RESPONSE_SIZE);
 224         data = reply->message + t80h->len - outputdatalength;
 225         if (copy_to_user(outputdata, data, outputdatalength))
 226                 return -EFAULT;
 227         return 0;
 228 }
 229
 230 static int convert_response(struct zcrypt_device *zdev,
 231                             struct ap_message *reply,
 232                             char __user *outputdata,
 233                             unsigned int outputdatalength)
 234 {
 235         /* Response type byte is the second byte in the response. */
 236         switch (((unsigned char *) reply->message)[1]) {
 237         case TYPE82_RSP_CODE:
 238         case TYPE88_RSP_CODE:
 239                 return convert_error(zdev, reply);
 240         case TYPE80_RSP_CODE:
 241                 return convert_type80(zdev, reply,
 242                                       outputdata, outputdatalength);
 243         default: /* Unknown response type, this should NEVER EVER happen */
 244                 PRINTK("Unrecognized Message Header: %08x%08x\n",
 245                        *(unsigned int *) reply->message,
 246                        *(unsigned int *) (reply->message+4));
 247                 zdev->online = 0;
 248                 return -EAGAIN; /* repeat the request on a different device. */
 249         }
 250 }
 251
 252 /**
 253  * This function is called from the AP bus code after a crypto request
 254  * "msg" has finished with the reply message "reply".
 255  * It is called from tasklet context.
 256  * @ap_dev: pointer to the AP device
 257  * @msg: pointer to the AP message
 258  * @reply: pointer to the AP reply message
 259  */
 260 static void zcrypt_cex2a_receive(struct ap_device *ap_dev,
 261                                  struct ap_message *msg,
 262                                  struct ap_message *reply)
 263 {
 264         static struct error_hdr error_reply = {
 265                 .type = TYPE82_RSP_CODE,
 266                 .reply_code = REP82_ERROR_MACHINE_FAILURE,
 267         };
 268         struct type80_hdr *t80h = reply->message;
 269         int length;
 270
 271         /* Copy the reply message to the request message buffer. */
 272         if (IS_ERR(reply))
 273                 memcpy(msg->message, &error_reply, sizeof(error_reply));
 274         else if (t80h->type == TYPE80_RSP_CODE) {
 275                 length = min(CEX2A_MAX_RESPONSE_SIZE, (int) t80h->len);
 276                 memcpy(msg->message, reply->message, length);
 277         } else
 278                 memcpy(msg->message, reply->message, sizeof error_reply);
 279         complete((struct completion *) msg->private);
 280 }
 281
 282 static atomic_t zcrypt_step = ATOMIC_INIT(0);
 283
 284 /**
 285  * The request distributor calls this function if it picked the CEX2A
 286  * device to handle a modexpo request.
 287  * @zdev: pointer to zcrypt_device structure that identifies the
 288  *        CEX2A device to the request distributor
 289  * @mex: pointer to the modexpo request buffer
 290  */
 291 static long zcrypt_cex2a_modexpo(struct zcrypt_device *zdev,
 292                                  struct ica_rsa_modexpo *mex)
 293 {
 294         struct ap_message ap_msg;
 295         struct completion work;
 296         int rc;
 297
 298         ap_msg.message = kmalloc(CEX2A_MAX_MESSAGE_SIZE, GFP_KERNEL);
 299         if (!ap_msg.message)
 300                 return -ENOMEM;
 301         ap_msg.psmid = (((unsigned long long) current->pid) << 32) +
 302                                 atomic_inc_return(&zcrypt_step);
 303         ap_msg.private = &work;
 304         rc = ICAMEX_msg_to_type50MEX_msg(zdev, &ap_msg, mex);
 305         if (rc)
 306                 goto out_free;
 307         init_completion(&work);
 308         ap_queue_message(zdev->ap_dev, &ap_msg);
 309         rc = wait_for_completion_interruptible_timeout(
 310                                 &work, CEX2A_CLEANUP_TIME);
 311         if (rc > 0)
 312                 rc = convert_response(zdev, &ap_msg, mex->outputdata,
 313                                       mex->outputdatalength);
 314         else {
 315                 /* Signal pending or message timed out. */
 316                 ap_cancel_message(zdev->ap_dev, &ap_msg);
 317                 if (rc == 0)
 318                         /* Message timed out. */
 319                         rc = -ETIME;
 320         }
 321 out_free:
 322         kfree(ap_msg.message);
 323         return rc;
 324 }
 325
 326 /**
 327  * The request distributor calls this function if it picked the CEX2A
 328  * device to handle a modexpo_crt request.
 329  * @zdev: pointer to zcrypt_device structure that identifies the
 330  *        CEX2A device to the request distributor
 331  * @crt: pointer to the modexpoc_crt request buffer
 332  */
 333 static long zcrypt_cex2a_modexpo_crt(struct zcrypt_device *zdev,
 334                                      struct ica_rsa_modexpo_crt *crt)
 335 {
 336         struct ap_message ap_msg;
 337         struct completion work;
 338         int rc;
 339
 340         ap_msg.message = kmalloc(CEX2A_MAX_MESSAGE_SIZE, GFP_KERNEL);
 341         if (!ap_msg.message)
 342                 return -ENOMEM;
 343         ap_msg.psmid = (((unsigned long long) current->pid) << 32) +
 344                                 atomic_inc_return(&zcrypt_step);
 345         ap_msg.private = &work;
 346         rc = ICACRT_msg_to_type50CRT_msg(zdev, &ap_msg, crt);
 347         if (rc)
 348                 goto out_free;
 349         init_completion(&work);
 350         ap_queue_message(zdev->ap_dev, &ap_msg);
 351         rc = wait_for_completion_interruptible_timeout(
 352                                 &work, CEX2A_CLEANUP_TIME);
 353         if (rc > 0)
 354                 rc = convert_response(zdev, &ap_msg, crt->outputdata,
 355                                       crt->outputdatalength);
 356         else {
 357                 /* Signal pending or message timed out. */
 358                 ap_cancel_message(zdev->ap_dev, &ap_msg);
 359                 if (rc == 0)
 360                         /* Message timed out. */
 361                         rc = -ETIME;
 362         }
 363 out_free:
 364         kfree(ap_msg.message);
 365         return rc;
 366 }
 367
 368 /**
 369  * The crypto operations for a CEX2A card.
 370  */
 371 static struct zcrypt_ops zcrypt_cex2a_ops = {
 372         .rsa_modexpo = zcrypt_cex2a_modexpo,
 373         .rsa_modexpo_crt = zcrypt_cex2a_modexpo_crt,
 374 };
 375
 376 /**
 377  * Probe function for CEX2A cards. It always accepts the AP device
 378  * since the bus_match already checked the hardware type.
 379  * @ap_dev: pointer to the AP device.
 380  */
 381 static int zcrypt_cex2a_probe(struct ap_device *ap_dev)
 382 {
 383         struct zcrypt_device *zdev;
 384         int rc;
 385
 386         zdev = zcrypt_device_alloc(CEX2A_MAX_RESPONSE_SIZE);
 387         if (!zdev)
 388                 return -ENOMEM;
 389         zdev->ap_dev = ap_dev;
 390         zdev->ops = &zcrypt_cex2a_ops;
 391         zdev->online = 1;
 392         zdev->user_space_type = ZCRYPT_CEX2A;
 393         zdev->type_string = "CEX2A";
 394         zdev->min_mod_size = CEX2A_MIN_MOD_SIZE;
 395         zdev->max_mod_size = CEX2A_MAX_MOD_SIZE;
 396         zdev->short_crt = 1;
 397         zdev->speed_rating = CEX2A_SPEED_RATING;
 398         ap_dev->reply = &zdev->reply;
 399         ap_dev->private = zdev;
 400         rc = zcrypt_device_register(zdev);
 401         if (rc)
 402                 goto out_free;
 403         return 0;
 404
 405 out_free:
 406         ap_dev->private = NULL;
 407         zcrypt_device_free(zdev);
 408         return rc;
 409 }
 410
 411 /**
 412  * This is called to remove the extended CEX2A driver information
 413  * if an AP device is removed.
 414  */
 415 static void zcrypt_cex2a_remove(struct ap_device *ap_dev)
 416 {
 417         struct zcrypt_device *zdev = ap_dev->private;
 418
 419         zcrypt_device_unregister(zdev);
 420 }
 421
 422 int __init zcrypt_cex2a_init(void)
 423 {
 424         return ap_driver_register(&zcrypt_cex2a_driver, THIS_MODULE, "cex2a");
 425 }
 426
 427 void __exit zcrypt_cex2a_exit(void)
 428 {
 429         ap_driver_unregister(&zcrypt_cex2a_driver);
 430 }
 431
 432 #ifndef CONFIG_ZCRYPT_MONOLITHIC
 433 module_init(zcrypt_cex2a_init);
 434 module_exit(zcrypt_cex2a_exit);
 435 #endif