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         { AP_DEVICE(AP_DEVICE_TYPE_CEX2A2) },
  53         { /* end of list */ },
  54 };
  55
  56 #ifndef CONFIG_ZCRYPT_MONOLITHIC
  57 MODULE_DEVICE_TABLE(ap, zcrypt_cex2a_ids);
  58 MODULE_AUTHOR("IBM Corporation");
  59 MODULE_DESCRIPTION("CEX2A Cryptographic Coprocessor device driver, "
  60                    "Copyright 2001, 2006 IBM Corporation");
  61 MODULE_LICENSE("GPL");
  62 #endif
  63
  64 static int zcrypt_cex2a_probe(struct ap_device *ap_dev);
  65 static void zcrypt_cex2a_remove(struct ap_device *ap_dev);
  66 static void zcrypt_cex2a_receive(struct ap_device *, struct ap_message *,
  67                                  struct ap_message *);
  68
  69 static struct ap_driver zcrypt_cex2a_driver = {
  70         .probe = zcrypt_cex2a_probe,
  71         .remove = zcrypt_cex2a_remove,
  72         .receive = zcrypt_cex2a_receive,
  73         .ids = zcrypt_cex2a_ids,
  74         .request_timeout = CEX2A_CLEANUP_TIME,
  75 };
  76
  77 /**
  78  * Convert a ICAMEX message to a type50 MEX message.
  79  *
  80  * @zdev: crypto device pointer
  81  * @zreq: crypto request pointer
  82  * @mex: pointer to user input data
  83  *
  84  * Returns 0 on success or -EFAULT.
  85  */
  86 static int ICAMEX_msg_to_type50MEX_msg(struct zcrypt_device *zdev,
  87                                        struct ap_message *ap_msg,
  88                                        struct ica_rsa_modexpo *mex)
  89 {
  90         unsigned char *mod, *exp, *inp;
  91         int mod_len;
  92
  93         mod_len = mex->inputdatalength;
  94
  95         if (mod_len <= 128) {
  96                 struct type50_meb1_msg *meb1 = ap_msg->message;
  97                 memset(meb1, 0, sizeof(*meb1));
  98                 ap_msg->length = sizeof(*meb1);
  99                 meb1->header.msg_type_code = TYPE50_TYPE_CODE;
 100                 meb1->header.msg_len = sizeof(*meb1);
 101                 meb1->keyblock_type = TYPE50_MEB1_FMT;
 102                 mod = meb1->modulus + sizeof(meb1->modulus) - mod_len;
 103                 exp = meb1->exponent + sizeof(meb1->exponent) - mod_len;
 104                 inp = meb1->message + sizeof(meb1->message) - mod_len;
 105         } else {
 106                 struct type50_meb2_msg *meb2 = ap_msg->message;
 107                 memset(meb2, 0, sizeof(*meb2));
 108                 ap_msg->length = sizeof(*meb2);
 109                 meb2->header.msg_type_code = TYPE50_TYPE_CODE;
 110                 meb2->header.msg_len = sizeof(*meb2);
 111                 meb2->keyblock_type = TYPE50_MEB2_FMT;
 112                 mod = meb2->modulus + sizeof(meb2->modulus) - mod_len;
 113                 exp = meb2->exponent + sizeof(meb2->exponent) - mod_len;
 114                 inp = meb2->message + sizeof(meb2->message) - mod_len;
 115         }
 116
 117         if (copy_from_user(mod, mex->n_modulus, mod_len) ||
 118             copy_from_user(exp, mex->b_key, mod_len) ||
 119             copy_from_user(inp, mex->inputdata, mod_len))
 120                 return -EFAULT;
 121         return 0;
 122 }
 123
 124 /**
 125  * Convert a ICACRT message to a type50 CRT message.
 126  *
 127  * @zdev: crypto device pointer
 128  * @zreq: crypto request pointer
 129  * @crt: pointer to user input data
 130  *
 131  * Returns 0 on success or -EFAULT.
 132  */
 133 static int ICACRT_msg_to_type50CRT_msg(struct zcrypt_device *zdev,
 134                                        struct ap_message *ap_msg,
 135                                        struct ica_rsa_modexpo_crt *crt)
 136 {
 137         int mod_len, short_len, long_len, long_offset;
 138         unsigned char *p, *q, *dp, *dq, *u, *inp;
 139
 140         mod_len = crt->inputdatalength;
 141         short_len = mod_len / 2;
 142         long_len = mod_len / 2 + 8;
 143
 144         /*
 145          * CEX2A cannot handle p, dp, or U > 128 bytes.
 146          * If we have one of these, we need to do extra checking.
 147          */
 148         if (long_len > 128) {
 149                 /*
 150                  * zcrypt_rsa_crt already checked for the leading
 151                  * zeroes of np_prime, bp_key and u_mult_inc.
 152                  */
 153                 long_offset = long_len - 128;
 154                 long_len = 128;
 155         } else
 156                 long_offset = 0;
 157
 158         /*
 159          * Instead of doing extra work for p, dp, U > 64 bytes, we'll just use
 160          * the larger message structure.
 161          */
 162         if (long_len <= 64) {
 163                 struct type50_crb1_msg *crb1 = ap_msg->message;
 164                 memset(crb1, 0, sizeof(*crb1));
 165                 ap_msg->length = sizeof(*crb1);
 166                 crb1->header.msg_type_code = TYPE50_TYPE_CODE;
 167                 crb1->header.msg_len = sizeof(*crb1);
 168                 crb1->keyblock_type = TYPE50_CRB1_FMT;
 169                 p = crb1->p + sizeof(crb1->p) - long_len;
 170                 q = crb1->q + sizeof(crb1->q) - short_len;
 171                 dp = crb1->dp + sizeof(crb1->dp) - long_len;
 172                 dq = crb1->dq + sizeof(crb1->dq) - short_len;
 173                 u = crb1->u + sizeof(crb1->u) - long_len;
 174                 inp = crb1->message + sizeof(crb1->message) - mod_len;
 175         } else {
 176                 struct type50_crb2_msg *crb2 = ap_msg->message;
 177                 memset(crb2, 0, sizeof(*crb2));
 178                 ap_msg->length = sizeof(*crb2);
 179                 crb2->header.msg_type_code = TYPE50_TYPE_CODE;
 180                 crb2->header.msg_len = sizeof(*crb2);
 181                 crb2->keyblock_type = TYPE50_CRB2_FMT;
 182                 p = crb2->p + sizeof(crb2->p) - long_len;
 183                 q = crb2->q + sizeof(crb2->q) - short_len;
 184                 dp = crb2->dp + sizeof(crb2->dp) - long_len;
 185                 dq = crb2->dq + sizeof(crb2->dq) - short_len;
 186                 u = crb2->u + sizeof(crb2->u) - long_len;
 187                 inp = crb2->message + sizeof(crb2->message) - mod_len;
 188         }
 189
 190         if (copy_from_user(p, crt->np_prime + long_offset, long_len) ||
 191             copy_from_user(q, crt->nq_prime, short_len) ||
 192             copy_from_user(dp, crt->bp_key + long_offset, long_len) ||
 193             copy_from_user(dq, crt->bq_key, short_len) ||
 194             copy_from_user(u, crt->u_mult_inv + long_offset, long_len) ||
 195             copy_from_user(inp, crt->inputdata, mod_len))
 196                 return -EFAULT;
 197
 198
 199         return 0;
 200 }
 201
 202 /**
 203  * Copy results from a type 80 reply message back to user space.
 204  *
 205  * @zdev: crypto device pointer
 206  * @reply: reply AP message.
 207  * @data: pointer to user output data
 208  * @length: size of user output data
 209  *
 210  * Returns 0 on success or -EFAULT.
 211  */
 212 static int convert_type80(struct zcrypt_device *zdev,
 213                           struct ap_message *reply,
 214                           char __user *outputdata,
 215                           unsigned int outputdatalength)
 216 {
 217         struct type80_hdr *t80h = reply->message;
 218         unsigned char *data;
 219
 220         if (t80h->len < sizeof(*t80h) + outputdatalength) {
 221                 /* The result is too short, the CEX2A card may not do that.. */
 222                 zdev->online = 0;
 223                 return -EAGAIN; /* repeat the request on a different device. */
 224         }
 225         BUG_ON(t80h->len > CEX2A_MAX_RESPONSE_SIZE);
 226         data = reply->message + t80h->len - outputdatalength;
 227         if (copy_to_user(outputdata, data, outputdatalength))
 228                 return -EFAULT;
 229         return 0;
 230 }
 231
 232 static int convert_response(struct zcrypt_device *zdev,
 233                             struct ap_message *reply,
 234                             char __user *outputdata,
 235                             unsigned int outputdatalength)
 236 {
 237         /* Response type byte is the second byte in the response. */
 238         switch (((unsigned char *) reply->message)[1]) {
 239         case TYPE82_RSP_CODE:
 240         case TYPE88_RSP_CODE:
 241                 return convert_error(zdev, reply);
 242         case TYPE80_RSP_CODE:
 243                 return convert_type80(zdev, reply,
 244                                       outputdata, outputdatalength);
 245         default: /* Unknown response type, this should NEVER EVER happen */
 246                 zdev->online = 0;
 247                 return -EAGAIN; /* repeat the request on a different device. */
 248         }
 249 }
 250
 251 /**
 252  * This function is called from the AP bus code after a crypto request
 253  * "msg" has finished with the reply message "reply".
 254  * It is called from tasklet context.
 255  * @ap_dev: pointer to the AP device
 256  * @msg: pointer to the AP message
 257  * @reply: pointer to the AP reply message
 258  */
 259 static void zcrypt_cex2a_receive(struct ap_device *ap_dev,
 260                                  struct ap_message *msg,
 261                                  struct ap_message *reply)
 262 {
 263         static struct error_hdr error_reply = {
 264                 .type = TYPE82_RSP_CODE,
 265                 .reply_code = REP82_ERROR_MACHINE_FAILURE,
 266         };
 267         struct type80_hdr *t80h;
 268         int length;
 269
 270         /* Copy the reply message to the request message buffer. */
 271         if (IS_ERR(reply)) {
 272                 memcpy(msg->message, &error_reply, sizeof(error_reply));
 273                 goto out;
 274         }
 275         t80h = reply->message;
 276         if (t80h->type == TYPE80_RSP_CODE) {
 277                 length = min(CEX2A_MAX_RESPONSE_SIZE, (int) t80h->len);
 278                 memcpy(msg->message, reply->message, length);
 279         } else
 280                 memcpy(msg->message, reply->message, sizeof error_reply);
 281 out:
 282         complete((struct completion *) msg->private);
 283 }
 284
 285 static atomic_t zcrypt_step = ATOMIC_INIT(0);
 286
 287 /**
 288  * The request distributor calls this function if it picked the CEX2A
 289  * device to handle a modexpo request.
 290  * @zdev: pointer to zcrypt_device structure that identifies the
 291  *        CEX2A device to the request distributor
 292  * @mex: pointer to the modexpo request buffer
 293  */
 294 static long zcrypt_cex2a_modexpo(struct zcrypt_device *zdev,
 295                                  struct ica_rsa_modexpo *mex)
 296 {
 297         struct ap_message ap_msg;
 298         struct completion work;
 299         int rc;
 300
 301         ap_msg.message = kmalloc(CEX2A_MAX_MESSAGE_SIZE, GFP_KERNEL);
 302         if (!ap_msg.message)
 303                 return -ENOMEM;
 304         ap_msg.psmid = (((unsigned long long) current->pid) << 32) +
 305                                 atomic_inc_return(&zcrypt_step);
 306         ap_msg.private = &work;
 307         rc = ICAMEX_msg_to_type50MEX_msg(zdev, &ap_msg, mex);
 308         if (rc)
 309                 goto out_free;
 310         init_completion(&work);
 311         ap_queue_message(zdev->ap_dev, &ap_msg);
 312         rc = wait_for_completion_interruptible(&work);
 313         if (rc == 0)
 314                 rc = convert_response(zdev, &ap_msg, mex->outputdata,
 315                                       mex->outputdatalength);
 316         else
 317                 /* Signal pending. */
 318                 ap_cancel_message(zdev->ap_dev, &ap_msg);
 319 out_free:
 320         kfree(ap_msg.message);
 321         return rc;
 322 }
 323
 324 /**
 325  * The request distributor calls this function if it picked the CEX2A
 326  * device to handle a modexpo_crt request.
 327  * @zdev: pointer to zcrypt_device structure that identifies the
 328  *        CEX2A device to the request distributor
 329  * @crt: pointer to the modexpoc_crt request buffer
 330  */
 331 static long zcrypt_cex2a_modexpo_crt(struct zcrypt_device *zdev,
 332                                      struct ica_rsa_modexpo_crt *crt)
 333 {
 334         struct ap_message ap_msg;
 335         struct completion work;
 336         int rc;
 337
 338         ap_msg.message = kmalloc(CEX2A_MAX_MESSAGE_SIZE, GFP_KERNEL);
 339         if (!ap_msg.message)
 340                 return -ENOMEM;
 341         ap_msg.psmid = (((unsigned long long) current->pid) << 32) +
 342                                 atomic_inc_return(&zcrypt_step);
 343         ap_msg.private = &work;
 344         rc = ICACRT_msg_to_type50CRT_msg(zdev, &ap_msg, crt);
 345         if (rc)
 346                 goto out_free;
 347         init_completion(&work);
 348         ap_queue_message(zdev->ap_dev, &ap_msg);
 349         rc = wait_for_completion_interruptible(&work);
 350         if (rc == 0)
 351                 rc = convert_response(zdev, &ap_msg, crt->outputdata,
 352                                       crt->outputdatalength);
 353         else
 354                 /* Signal pending. */
 355                 ap_cancel_message(zdev->ap_dev, &ap_msg);
 356 out_free:
 357         kfree(ap_msg.message);
 358         return rc;
 359 }
 360
 361 /**
 362  * The crypto operations for a CEX2A card.
 363  */
 364 static struct zcrypt_ops zcrypt_cex2a_ops = {
 365         .rsa_modexpo = zcrypt_cex2a_modexpo,
 366         .rsa_modexpo_crt = zcrypt_cex2a_modexpo_crt,
 367 };
 368
 369 /**
 370  * Probe function for CEX2A cards. It always accepts the AP device
 371  * since the bus_match already checked the hardware type.
 372  * @ap_dev: pointer to the AP device.
 373  */
 374 static int zcrypt_cex2a_probe(struct ap_device *ap_dev)
 375 {
 376         struct zcrypt_device *zdev;
 377         int rc;
 378
 379         zdev = zcrypt_device_alloc(CEX2A_MAX_RESPONSE_SIZE);
 380         if (!zdev)
 381                 return -ENOMEM;
 382         zdev->ap_dev = ap_dev;
 383         zdev->ops = &zcrypt_cex2a_ops;
 384         zdev->online = 1;
 385         zdev->user_space_type = ZCRYPT_CEX2A;
 386         zdev->type_string = "CEX2A";
 387         zdev->min_mod_size = CEX2A_MIN_MOD_SIZE;
 388         zdev->max_mod_size = CEX2A_MAX_MOD_SIZE;
 389         zdev->short_crt = 1;
 390         zdev->speed_rating = CEX2A_SPEED_RATING;
 391         ap_dev->reply = &zdev->reply;
 392         ap_dev->private = zdev;
 393         rc = zcrypt_device_register(zdev);
 394         if (rc)
 395                 goto out_free;
 396         return 0;
 397
 398 out_free:
 399         ap_dev->private = NULL;
 400         zcrypt_device_free(zdev);
 401         return rc;
 402 }
 403
 404 /**
 405  * This is called to remove the extended CEX2A driver information
 406  * if an AP device is removed.
 407  */
 408 static void zcrypt_cex2a_remove(struct ap_device *ap_dev)
 409 {
 410         struct zcrypt_device *zdev = ap_dev->private;
 411
 412         zcrypt_device_unregister(zdev);
 413 }
 414
 415 int __init zcrypt_cex2a_init(void)
 416 {
 417         return ap_driver_register(&zcrypt_cex2a_driver, THIS_MODULE, "cex2a");
 418 }
 419
 420 void __exit zcrypt_cex2a_exit(void)
 421 {
 422         ap_driver_unregister(&zcrypt_cex2a_driver);
 423 }
 424
 425 #ifndef CONFIG_ZCRYPT_MONOLITHIC
 426 module_init(zcrypt_cex2a_init);
 427 module_exit(zcrypt_cex2a_exit);
 428 #endif