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         .request_timeout = CEX2A_CLEANUP_TIME,
  74 };
  75
  76 /**
  77  * Convert a ICAMEX message to a type50 MEX message.
  78  *
  79  * @zdev: crypto device pointer
  80  * @zreq: crypto request pointer
  81  * @mex: pointer to user input data
  82  *
  83  * Returns 0 on success or -EFAULT.
  84  */
  85 static int ICAMEX_msg_to_type50MEX_msg(struct zcrypt_device *zdev,
  86                                        struct ap_message *ap_msg,
  87                                        struct ica_rsa_modexpo *mex)
  88 {
  89         unsigned char *mod, *exp, *inp;
  90         int mod_len;
  91
  92         mod_len = mex->inputdatalength;
  93
  94         if (mod_len <= 128) {
  95                 struct type50_meb1_msg *meb1 = ap_msg->message;
  96                 memset(meb1, 0, sizeof(*meb1));
  97                 ap_msg->length = sizeof(*meb1);
  98                 meb1->header.msg_type_code = TYPE50_TYPE_CODE;
  99                 meb1->header.msg_len = sizeof(*meb1);
 100                 meb1->keyblock_type = TYPE50_MEB1_FMT;
 101                 mod = meb1->modulus + sizeof(meb1->modulus) - mod_len;
 102                 exp = meb1->exponent + sizeof(meb1->exponent) - mod_len;
 103                 inp = meb1->message + sizeof(meb1->message) - mod_len;
 104         } else {
 105                 struct type50_meb2_msg *meb2 = ap_msg->message;
 106                 memset(meb2, 0, sizeof(*meb2));
 107                 ap_msg->length = sizeof(*meb2);
 108                 meb2->header.msg_type_code = TYPE50_TYPE_CODE;
 109                 meb2->header.msg_len = sizeof(*meb2);
 110                 meb2->keyblock_type = TYPE50_MEB2_FMT;
 111                 mod = meb2->modulus + sizeof(meb2->modulus) - mod_len;
 112                 exp = meb2->exponent + sizeof(meb2->exponent) - mod_len;
 113                 inp = meb2->message + sizeof(meb2->message) - mod_len;
 114         }
 115
 116         if (copy_from_user(mod, mex->n_modulus, mod_len) ||
 117             copy_from_user(exp, mex->b_key, mod_len) ||
 118             copy_from_user(inp, mex->inputdata, mod_len))
 119                 return -EFAULT;
 120         return 0;
 121 }
 122
 123 /**
 124  * Convert a ICACRT message to a type50 CRT message.
 125  *
 126  * @zdev: crypto device pointer
 127  * @zreq: crypto request pointer
 128  * @crt: pointer to user input data
 129  *
 130  * Returns 0 on success or -EFAULT.
 131  */
 132 static int ICACRT_msg_to_type50CRT_msg(struct zcrypt_device *zdev,
 133                                        struct ap_message *ap_msg,
 134                                        struct ica_rsa_modexpo_crt *crt)
 135 {
 136         int mod_len, short_len, long_len, long_offset;
 137         unsigned char *p, *q, *dp, *dq, *u, *inp;
 138
 139         mod_len = crt->inputdatalength;
 140         short_len = mod_len / 2;
 141         long_len = mod_len / 2 + 8;
 142
 143         /*
 144          * CEX2A cannot handle p, dp, or U > 128 bytes.
 145          * If we have one of these, we need to do extra checking.
 146          */
 147         if (long_len > 128) {
 148                 /*
 149                  * zcrypt_rsa_crt already checked for the leading
 150                  * zeroes of np_prime, bp_key and u_mult_inc.
 151                  */
 152                 long_offset = long_len - 128;
 153                 long_len = 128;
 154         } else
 155                 long_offset = 0;
 156
 157         /*
 158          * Instead of doing extra work for p, dp, U > 64 bytes, we'll just use
 159          * the larger message structure.
 160          */
 161         if (long_len <= 64) {
 162                 struct type50_crb1_msg *crb1 = ap_msg->message;
 163                 memset(crb1, 0, sizeof(*crb1));
 164                 ap_msg->length = sizeof(*crb1);
 165                 crb1->header.msg_type_code = TYPE50_TYPE_CODE;
 166                 crb1->header.msg_len = sizeof(*crb1);
 167                 crb1->keyblock_type = TYPE50_CRB1_FMT;
 168                 p = crb1->p + sizeof(crb1->p) - long_len;
 169                 q = crb1->q + sizeof(crb1->q) - short_len;
 170                 dp = crb1->dp + sizeof(crb1->dp) - long_len;
 171                 dq = crb1->dq + sizeof(crb1->dq) - short_len;
 172                 u = crb1->u + sizeof(crb1->u) - long_len;
 173                 inp = crb1->message + sizeof(crb1->message) - mod_len;
 174         } else {
 175                 struct type50_crb2_msg *crb2 = ap_msg->message;
 176                 memset(crb2, 0, sizeof(*crb2));
 177                 ap_msg->length = sizeof(*crb2);
 178                 crb2->header.msg_type_code = TYPE50_TYPE_CODE;
 179                 crb2->header.msg_len = sizeof(*crb2);
 180                 crb2->keyblock_type = TYPE50_CRB2_FMT;
 181                 p = crb2->p + sizeof(crb2->p) - long_len;
 182                 q = crb2->q + sizeof(crb2->q) - short_len;
 183                 dp = crb2->dp + sizeof(crb2->dp) - long_len;
 184                 dq = crb2->dq + sizeof(crb2->dq) - short_len;
 185                 u = crb2->u + sizeof(crb2->u) - long_len;
 186                 inp = crb2->message + sizeof(crb2->message) - mod_len;
 187         }
 188
 189         if (copy_from_user(p, crt->np_prime + long_offset, long_len) ||
 190             copy_from_user(q, crt->nq_prime, short_len) ||
 191             copy_from_user(dp, crt->bp_key + long_offset, long_len) ||
 192             copy_from_user(dq, crt->bq_key, short_len) ||
 193             copy_from_user(u, crt->u_mult_inv + long_offset, long_len) ||
 194             copy_from_user(inp, crt->inputdata, mod_len))
 195                 return -EFAULT;
 196
 197
 198         return 0;
 199 }
 200
 201 /**
 202  * Copy results from a type 80 reply message back to user space.
 203  *
 204  * @zdev: crypto device pointer
 205  * @reply: reply AP message.
 206  * @data: pointer to user output data
 207  * @length: size of user output data
 208  *
 209  * Returns 0 on success or -EFAULT.
 210  */
 211 static int convert_type80(struct zcrypt_device *zdev,
 212                           struct ap_message *reply,
 213                           char __user *outputdata,
 214                           unsigned int outputdatalength)
 215 {
 216         struct type80_hdr *t80h = reply->message;
 217         unsigned char *data;
 218
 219         if (t80h->len < sizeof(*t80h) + outputdatalength) {
 220                 /* The result is too short, the CEX2A card may not do that.. */
 221                 zdev->online = 0;
 222                 return -EAGAIN; /* repeat the request on a different device. */
 223         }
 224         BUG_ON(t80h->len > CEX2A_MAX_RESPONSE_SIZE);
 225         data = reply->message + t80h->len - outputdatalength;
 226         if (copy_to_user(outputdata, data, outputdatalength))
 227                 return -EFAULT;
 228         return 0;
 229 }
 230
 231 static int convert_response(struct zcrypt_device *zdev,
 232                             struct ap_message *reply,
 233                             char __user *outputdata,
 234                             unsigned int outputdatalength)
 235 {
 236         /* Response type byte is the second byte in the response. */
 237         switch (((unsigned char *) reply->message)[1]) {
 238         case TYPE82_RSP_CODE:
 239         case TYPE88_RSP_CODE:
 240                 return convert_error(zdev, reply);
 241         case TYPE80_RSP_CODE:
 242                 return convert_type80(zdev, reply,
 243                                       outputdata, outputdatalength);
 244         default: /* Unknown response type, this should NEVER EVER happen */
 245                 PRINTK("Unrecognized Message Header: %08x%08x\n",
 246                        *(unsigned int *) reply->message,
 247                        *(unsigned int *) (reply->message+4));
 248                 zdev->online = 0;
 249                 return -EAGAIN; /* repeat the request on a different device. */
 250         }
 251 }
 252
 253 /**
 254  * This function is called from the AP bus code after a crypto request
 255  * "msg" has finished with the reply message "reply".
 256  * It is called from tasklet context.
 257  * @ap_dev: pointer to the AP device
 258  * @msg: pointer to the AP message
 259  * @reply: pointer to the AP reply message
 260  */
 261 static void zcrypt_cex2a_receive(struct ap_device *ap_dev,
 262                                  struct ap_message *msg,
 263                                  struct ap_message *reply)
 264 {
 265         static struct error_hdr error_reply = {
 266                 .type = TYPE82_RSP_CODE,
 267                 .reply_code = REP82_ERROR_MACHINE_FAILURE,
 268         };
 269         struct type80_hdr *t80h = reply->message;
 270         int length;
 271
 272         /* Copy the reply message to the request message buffer. */
 273         if (IS_ERR(reply))
 274                 memcpy(msg->message, &error_reply, sizeof(error_reply));
 275         else if (t80h->type == TYPE80_RSP_CODE) {
 276                 length = min(CEX2A_MAX_RESPONSE_SIZE, (int) t80h->len);
 277                 memcpy(msg->message, reply->message, length);
 278         } else
 279                 memcpy(msg->message, reply->message, sizeof error_reply);
 280         complete((struct completion *) msg->private);
 281 }
 282
 283 static atomic_t zcrypt_step = ATOMIC_INIT(0);
 284
 285 /**
 286  * The request distributor calls this function if it picked the CEX2A
 287  * device to handle a modexpo request.
 288  * @zdev: pointer to zcrypt_device structure that identifies the
 289  *        CEX2A device to the request distributor
 290  * @mex: pointer to the modexpo request buffer
 291  */
 292 static long zcrypt_cex2a_modexpo(struct zcrypt_device *zdev,
 293                                  struct ica_rsa_modexpo *mex)
 294 {
 295         struct ap_message ap_msg;
 296         struct completion work;
 297         int rc;
 298
 299         ap_msg.message = kmalloc(CEX2A_MAX_MESSAGE_SIZE, GFP_KERNEL);
 300         if (!ap_msg.message)
 301                 return -ENOMEM;
 302         ap_msg.psmid = (((unsigned long long) current->pid) << 32) +
 303                                 atomic_inc_return(&zcrypt_step);
 304         ap_msg.private = &work;
 305         rc = ICAMEX_msg_to_type50MEX_msg(zdev, &ap_msg, mex);
 306         if (rc)
 307                 goto out_free;
 308         init_completion(&work);
 309         ap_queue_message(zdev->ap_dev, &ap_msg);
 310         rc = wait_for_completion_interruptible(&work);
 311         if (rc == 0)
 312                 rc = convert_response(zdev, &ap_msg, mex->outputdata,
 313                                       mex->outputdatalength);
 314         else
 315                 /* Signal pending. */
 316                 ap_cancel_message(zdev->ap_dev, &ap_msg);
 317 out_free:
 318         kfree(ap_msg.message);
 319         return rc;
 320 }
 321
 322 /**
 323  * The request distributor calls this function if it picked the CEX2A
 324  * device to handle a modexpo_crt request.
 325  * @zdev: pointer to zcrypt_device structure that identifies the
 326  *        CEX2A device to the request distributor
 327  * @crt: pointer to the modexpoc_crt request buffer
 328  */
 329 static long zcrypt_cex2a_modexpo_crt(struct zcrypt_device *zdev,
 330                                      struct ica_rsa_modexpo_crt *crt)
 331 {
 332         struct ap_message ap_msg;
 333         struct completion work;
 334         int rc;
 335
 336         ap_msg.message = kmalloc(CEX2A_MAX_MESSAGE_SIZE, GFP_KERNEL);
 337         if (!ap_msg.message)
 338                 return -ENOMEM;
 339         ap_msg.psmid = (((unsigned long long) current->pid) << 32) +
 340                                 atomic_inc_return(&zcrypt_step);
 341         ap_msg.private = &work;
 342         rc = ICACRT_msg_to_type50CRT_msg(zdev, &ap_msg, crt);
 343         if (rc)
 344                 goto out_free;
 345         init_completion(&work);
 346         ap_queue_message(zdev->ap_dev, &ap_msg);
 347         rc = wait_for_completion_interruptible(&work);
 348         if (rc == 0)
 349                 rc = convert_response(zdev, &ap_msg, crt->outputdata,
 350                                       crt->outputdatalength);
 351         else
 352                 /* Signal pending. */
 353                 ap_cancel_message(zdev->ap_dev, &ap_msg);
 354 out_free:
 355         kfree(ap_msg.message);
 356         return rc;
 357 }
 358
 359 /**
 360  * The crypto operations for a CEX2A card.
 361  */
 362 static struct zcrypt_ops zcrypt_cex2a_ops = {
 363         .rsa_modexpo = zcrypt_cex2a_modexpo,
 364         .rsa_modexpo_crt = zcrypt_cex2a_modexpo_crt,
 365 };
 366
 367 /**
 368  * Probe function for CEX2A cards. It always accepts the AP device
 369  * since the bus_match already checked the hardware type.
 370  * @ap_dev: pointer to the AP device.
 371  */
 372 static int zcrypt_cex2a_probe(struct ap_device *ap_dev)
 373 {
 374         struct zcrypt_device *zdev;
 375         int rc;
 376
 377         zdev = zcrypt_device_alloc(CEX2A_MAX_RESPONSE_SIZE);
 378         if (!zdev)
 379                 return -ENOMEM;
 380         zdev->ap_dev = ap_dev;
 381         zdev->ops = &zcrypt_cex2a_ops;
 382         zdev->online = 1;
 383         zdev->user_space_type = ZCRYPT_CEX2A;
 384         zdev->type_string = "CEX2A";
 385         zdev->min_mod_size = CEX2A_MIN_MOD_SIZE;
 386         zdev->max_mod_size = CEX2A_MAX_MOD_SIZE;
 387         zdev->short_crt = 1;
 388         zdev->speed_rating = CEX2A_SPEED_RATING;
 389         ap_dev->reply = &zdev->reply;
 390         ap_dev->private = zdev;
 391         rc = zcrypt_device_register(zdev);
 392         if (rc)
 393                 goto out_free;
 394         return 0;
 395
 396 out_free:
 397         ap_dev->private = NULL;
 398         zcrypt_device_free(zdev);
 399         return rc;
 400 }
 401
 402 /**
 403  * This is called to remove the extended CEX2A driver information
 404  * if an AP device is removed.
 405  */
 406 static void zcrypt_cex2a_remove(struct ap_device *ap_dev)
 407 {
 408         struct zcrypt_device *zdev = ap_dev->private;
 409
 410         zcrypt_device_unregister(zdev);
 411 }
 412
 413 int __init zcrypt_cex2a_init(void)
 414 {
 415         return ap_driver_register(&zcrypt_cex2a_driver, THIS_MODULE, "cex2a");
 416 }
 417
 418 void __exit zcrypt_cex2a_exit(void)
 419 {
 420         ap_driver_unregister(&zcrypt_cex2a_driver);
 421 }
 422
 423 #ifndef CONFIG_ZCRYPT_MONOLITHIC
 424 module_init(zcrypt_cex2a_init);
 425 module_exit(zcrypt_cex2a_exit);
 426 #endif