drivers/s390/crypto/zcrypt_pcica.c

   1 /*
   2  *  zcrypt 2.1.0
   3  *
   4  *  Copyright IBM Corp. 2001, 2006
   5  *  Author(s): Robert Burroughs
   6  *             Eric Rossman (edrossma@us.ibm.com)
   7  *
   8  *  Hotplug & misc device support: Jochen Roehrig (roehrig@de.ibm.com)
   9  *  Major cleanup & driver split: Martin Schwidefsky <schwidefsky@de.ibm.com>
  10  *                                Ralph Wuerthner <rwuerthn@de.ibm.com>
  11  *
  12  * This program is free software; you can redistribute it and/or modify
  13  * it under the terms of the GNU General Public License as published by
  14  * the Free Software Foundation; either version 2, or (at your option)
  15  * any later version.
  16  *
  17  * This program is distributed in the hope that it will be useful,
  18  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  19  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  20  * GNU General Public License for more details.
  21  *
  22  * You should have received a copy of the GNU General Public License
  23  * along with this program; if not, write to the Free Software
  24  * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  25  */
  26
  27 #include <linux/module.h>
  28 #include <linux/slab.h>
  29 #include <linux/init.h>
  30 #include <linux/err.h>
  31 #include <linux/atomic.h>
  32 #include <asm/uaccess.h>
  33
  34 #include "ap_bus.h"
  35 #include "zcrypt_api.h"
  36 #include "zcrypt_error.h"
  37 #include "zcrypt_pcica.h"
  38
  39 #define PCICA_MIN_MOD_SIZE        1     /*    8 bits    */
  40 #define PCICA_MAX_MOD_SIZE      256     /* 2048 bits    */
  41
  42 #define PCICA_SPEED_RATING      2800
  43
  44 #define PCICA_MAX_MESSAGE_SIZE  0x3a0   /* sizeof(struct type4_lcr)          */
  45 #define PCICA_MAX_RESPONSE_SIZE 0x110   /* max outputdatalength + type80_hdr */
  46
  47 #define PCICA_CLEANUP_TIME      (15*HZ)
  48
  49 static struct ap_device_id zcrypt_pcica_ids[] = {
  50         { AP_DEVICE(AP_DEVICE_TYPE_PCICA) },
  51         { /* end of list */ },
  52 };
  53
  54 MODULE_DEVICE_TABLE(ap, zcrypt_pcica_ids);
  55 MODULE_AUTHOR("IBM Corporation");
  56 MODULE_DESCRIPTION("PCICA Cryptographic Coprocessor device driver, "
  57                    "Copyright IBM Corp. 2001, 2006");
  58 MODULE_LICENSE("GPL");
  59
  60 static int zcrypt_pcica_probe(struct ap_device *ap_dev);
  61 static void zcrypt_pcica_remove(struct ap_device *ap_dev);
  62 static void zcrypt_pcica_receive(struct ap_device *, struct ap_message *,
  63                                  struct ap_message *);
  64
  65 static struct ap_driver zcrypt_pcica_driver = {
  66         .probe = zcrypt_pcica_probe,
  67         .remove = zcrypt_pcica_remove,
  68         .ids = zcrypt_pcica_ids,
  69         .request_timeout = PCICA_CLEANUP_TIME,
  70 };
  71
  72 /**
  73  * Convert a ICAMEX message to a type4 MEX message.
  74  *
  75  * @zdev: crypto device pointer
  76  * @zreq: crypto request pointer
  77  * @mex: pointer to user input data
  78  *
  79  * Returns 0 on success or -EFAULT.
  80  */
  81 static int ICAMEX_msg_to_type4MEX_msg(struct zcrypt_device *zdev,
  82                                       struct ap_message *ap_msg,
  83                                       struct ica_rsa_modexpo *mex)
  84 {
  85         unsigned char *modulus, *exponent, *message;
  86         int mod_len;
  87
  88         mod_len = mex->inputdatalength;
  89
  90         if (mod_len <= 128) {
  91                 struct type4_sme *sme = ap_msg->message;
  92                 memset(sme, 0, sizeof(*sme));
  93                 ap_msg->length = sizeof(*sme);
  94                 sme->header.msg_fmt = TYPE4_SME_FMT;
  95                 sme->header.msg_len = sizeof(*sme);
  96                 sme->header.msg_type_code = TYPE4_TYPE_CODE;
  97                 sme->header.request_code = TYPE4_REQU_CODE;
  98                 modulus = sme->modulus + sizeof(sme->modulus) - mod_len;
  99                 exponent = sme->exponent + sizeof(sme->exponent) - mod_len;
 100                 message = sme->message + sizeof(sme->message) - mod_len;
 101         } else {
 102                 struct type4_lme *lme = ap_msg->message;
 103                 memset(lme, 0, sizeof(*lme));
 104                 ap_msg->length = sizeof(*lme);
 105                 lme->header.msg_fmt = TYPE4_LME_FMT;
 106                 lme->header.msg_len = sizeof(*lme);
 107                 lme->header.msg_type_code = TYPE4_TYPE_CODE;
 108                 lme->header.request_code = TYPE4_REQU_CODE;
 109                 modulus = lme->modulus + sizeof(lme->modulus) - mod_len;
 110                 exponent = lme->exponent + sizeof(lme->exponent) - mod_len;
 111                 message = lme->message + sizeof(lme->message) - mod_len;
 112         }
 113
 114         if (copy_from_user(modulus, mex->n_modulus, mod_len) ||
 115             copy_from_user(exponent, mex->b_key, mod_len) ||
 116             copy_from_user(message, mex->inputdata, mod_len))
 117                 return -EFAULT;
 118         return 0;
 119 }
 120
 121 /**
 122  * Convert a ICACRT message to a type4 CRT message.
 123  *
 124  * @zdev: crypto device pointer
 125  * @zreq: crypto request pointer
 126  * @crt: pointer to user input data
 127  *
 128  * Returns 0 on success or -EFAULT.
 129  */
 130 static int ICACRT_msg_to_type4CRT_msg(struct zcrypt_device *zdev,
 131                                       struct ap_message *ap_msg,
 132                                       struct ica_rsa_modexpo_crt *crt)
 133 {
 134         unsigned char *p, *q, *dp, *dq, *u, *inp;
 135         int mod_len, short_len, long_len;
 136
 137         mod_len = crt->inputdatalength;
 138         short_len = mod_len / 2;
 139         long_len = mod_len / 2 + 8;
 140
 141         if (mod_len <= 128) {
 142                 struct type4_scr *scr = ap_msg->message;
 143                 memset(scr, 0, sizeof(*scr));
 144                 ap_msg->length = sizeof(*scr);
 145                 scr->header.msg_type_code = TYPE4_TYPE_CODE;
 146                 scr->header.request_code = TYPE4_REQU_CODE;
 147                 scr->header.msg_fmt = TYPE4_SCR_FMT;
 148                 scr->header.msg_len = sizeof(*scr);
 149                 p = scr->p + sizeof(scr->p) - long_len;
 150                 q = scr->q + sizeof(scr->q) - short_len;
 151                 dp = scr->dp + sizeof(scr->dp) - long_len;
 152                 dq = scr->dq + sizeof(scr->dq) - short_len;
 153                 u = scr->u + sizeof(scr->u) - long_len;
 154                 inp = scr->message + sizeof(scr->message) - mod_len;
 155         } else {
 156                 struct type4_lcr *lcr = ap_msg->message;
 157                 memset(lcr, 0, sizeof(*lcr));
 158                 ap_msg->length = sizeof(*lcr);
 159                 lcr->header.msg_type_code = TYPE4_TYPE_CODE;
 160                 lcr->header.request_code = TYPE4_REQU_CODE;
 161                 lcr->header.msg_fmt = TYPE4_LCR_FMT;
 162                 lcr->header.msg_len = sizeof(*lcr);
 163                 p = lcr->p + sizeof(lcr->p) - long_len;
 164                 q = lcr->q + sizeof(lcr->q) - short_len;
 165                 dp = lcr->dp + sizeof(lcr->dp) - long_len;
 166                 dq = lcr->dq + sizeof(lcr->dq) - short_len;
 167                 u = lcr->u + sizeof(lcr->u) - long_len;
 168                 inp = lcr->message + sizeof(lcr->message) - mod_len;
 169         }
 170
 171         if (copy_from_user(p, crt->np_prime, long_len) ||
 172             copy_from_user(q, crt->nq_prime, short_len) ||
 173             copy_from_user(dp, crt->bp_key, long_len) ||
 174             copy_from_user(dq, crt->bq_key, short_len) ||
 175             copy_from_user(u, crt->u_mult_inv, long_len) ||
 176             copy_from_user(inp, crt->inputdata, mod_len))
 177                 return -EFAULT;
 178         return 0;
 179 }
 180
 181 /**
 182  * Copy results from a type 84 reply message back to user space.
 183  *
 184  * @zdev: crypto device pointer
 185  * @reply: reply AP message.
 186  * @data: pointer to user output data
 187  * @length: size of user output data
 188  *
 189  * Returns 0 on success or -EFAULT.
 190  */
 191 static int convert_type84(struct zcrypt_device *zdev,
 192                           struct ap_message *reply,
 193                           char __user *outputdata,
 194                           unsigned int outputdatalength)
 195 {
 196         struct type84_hdr *t84h = reply->message;
 197         char *data;
 198
 199         if (t84h->len < sizeof(*t84h) + outputdatalength) {
 200                 /* The result is too short, the PCICA card may not do that.. */
 201                 zdev->online = 0;
 202                 return -EAGAIN; /* repeat the request on a different device. */
 203         }
 204         BUG_ON(t84h->len > PCICA_MAX_RESPONSE_SIZE);
 205         data = reply->message + t84h->len - outputdatalength;
 206         if (copy_to_user(outputdata, data, outputdatalength))
 207                 return -EFAULT;
 208         return 0;
 209 }
 210
 211 static int convert_response(struct zcrypt_device *zdev,
 212                             struct ap_message *reply,
 213                             char __user *outputdata,
 214                             unsigned int outputdatalength)
 215 {
 216         /* Response type byte is the second byte in the response. */
 217         switch (((unsigned char *) reply->message)[1]) {
 218         case TYPE82_RSP_CODE:
 219         case TYPE88_RSP_CODE:
 220                 return convert_error(zdev, reply);
 221         case TYPE84_RSP_CODE:
 222                 return convert_type84(zdev, reply,
 223                                       outputdata, outputdatalength);
 224         default: /* Unknown response type, this should NEVER EVER happen */
 225                 zdev->online = 0;
 226                 return -EAGAIN; /* repeat the request on a different device. */
 227         }
 228 }
 229
 230 /**
 231  * This function is called from the AP bus code after a crypto request
 232  * "msg" has finished with the reply message "reply".
 233  * It is called from tasklet context.
 234  * @ap_dev: pointer to the AP device
 235  * @msg: pointer to the AP message
 236  * @reply: pointer to the AP reply message
 237  */
 238 static void zcrypt_pcica_receive(struct ap_device *ap_dev,
 239                                  struct ap_message *msg,
 240                                  struct ap_message *reply)
 241 {
 242         static struct error_hdr error_reply = {
 243                 .type = TYPE82_RSP_CODE,
 244                 .reply_code = REP82_ERROR_MACHINE_FAILURE,
 245         };
 246         struct type84_hdr *t84h;
 247         int length;
 248
 249         /* Copy the reply message to the request message buffer. */
 250         if (IS_ERR(reply)) {
 251                 memcpy(msg->message, &error_reply, sizeof(error_reply));
 252                 goto out;
 253         }
 254         t84h = reply->message;
 255         if (t84h->code == TYPE84_RSP_CODE) {
 256                 length = min(PCICA_MAX_RESPONSE_SIZE, (int) t84h->len);
 257                 memcpy(msg->message, reply->message, length);
 258         } else
 259                 memcpy(msg->message, reply->message, sizeof error_reply);
 260 out:
 261         complete((struct completion *) msg->private);
 262 }
 263
 264 static atomic_t zcrypt_step = ATOMIC_INIT(0);
 265
 266 /**
 267  * The request distributor calls this function if it picked the PCICA
 268  * device to handle a modexpo request.
 269  * @zdev: pointer to zcrypt_device structure that identifies the
 270  *        PCICA device to the request distributor
 271  * @mex: pointer to the modexpo request buffer
 272  */
 273 static long zcrypt_pcica_modexpo(struct zcrypt_device *zdev,
 274                                  struct ica_rsa_modexpo *mex)
 275 {
 276         struct ap_message ap_msg;
 277         struct completion work;
 278         int rc;
 279
 280         ap_init_message(&ap_msg);
 281         ap_msg.message = kmalloc(PCICA_MAX_MESSAGE_SIZE, GFP_KERNEL);
 282         if (!ap_msg.message)
 283                 return -ENOMEM;
 284         ap_msg.receive = zcrypt_pcica_receive;
 285         ap_msg.psmid = (((unsigned long long) current->pid) << 32) +
 286                                 atomic_inc_return(&zcrypt_step);
 287         ap_msg.private = &work;
 288         rc = ICAMEX_msg_to_type4MEX_msg(zdev, &ap_msg, mex);
 289         if (rc)
 290                 goto out_free;
 291         init_completion(&work);
 292         ap_queue_message(zdev->ap_dev, &ap_msg);
 293         rc = wait_for_completion_interruptible(&work);
 294         if (rc == 0)
 295                 rc = convert_response(zdev, &ap_msg, mex->outputdata,
 296                                       mex->outputdatalength);
 297         else
 298                 /* Signal pending. */
 299                 ap_cancel_message(zdev->ap_dev, &ap_msg);
 300 out_free:
 301         kfree(ap_msg.message);
 302         return rc;
 303 }
 304
 305 /**
 306  * The request distributor calls this function if it picked the PCICA
 307  * device to handle a modexpo_crt request.
 308  * @zdev: pointer to zcrypt_device structure that identifies the
 309  *        PCICA device to the request distributor
 310  * @crt: pointer to the modexpoc_crt request buffer
 311  */
 312 static long zcrypt_pcica_modexpo_crt(struct zcrypt_device *zdev,
 313                                      struct ica_rsa_modexpo_crt *crt)
 314 {
 315         struct ap_message ap_msg;
 316         struct completion work;
 317         int rc;
 318
 319         ap_init_message(&ap_msg);
 320         ap_msg.message = kmalloc(PCICA_MAX_MESSAGE_SIZE, GFP_KERNEL);
 321         if (!ap_msg.message)
 322                 return -ENOMEM;
 323         ap_msg.receive = zcrypt_pcica_receive;
 324         ap_msg.psmid = (((unsigned long long) current->pid) << 32) +
 325                                 atomic_inc_return(&zcrypt_step);
 326         ap_msg.private = &work;
 327         rc = ICACRT_msg_to_type4CRT_msg(zdev, &ap_msg, crt);
 328         if (rc)
 329                 goto out_free;
 330         init_completion(&work);
 331         ap_queue_message(zdev->ap_dev, &ap_msg);
 332         rc = wait_for_completion_interruptible(&work);
 333         if (rc == 0)
 334                 rc = convert_response(zdev, &ap_msg, crt->outputdata,
 335                                       crt->outputdatalength);
 336         else
 337                 /* Signal pending. */
 338                 ap_cancel_message(zdev->ap_dev, &ap_msg);
 339 out_free:
 340         kfree(ap_msg.message);
 341         return rc;
 342 }
 343
 344 /**
 345  * The crypto operations for a PCICA card.
 346  */
 347 static struct zcrypt_ops zcrypt_pcica_ops = {
 348         .rsa_modexpo = zcrypt_pcica_modexpo,
 349         .rsa_modexpo_crt = zcrypt_pcica_modexpo_crt,
 350 };
 351
 352 /**
 353  * Probe function for PCICA cards. It always accepts the AP device
 354  * since the bus_match already checked the hardware type.
 355  * @ap_dev: pointer to the AP device.
 356  */
 357 static int zcrypt_pcica_probe(struct ap_device *ap_dev)
 358 {
 359         struct zcrypt_device *zdev;
 360         int rc;
 361
 362         zdev = zcrypt_device_alloc(PCICA_MAX_RESPONSE_SIZE);
 363         if (!zdev)
 364                 return -ENOMEM;
 365         zdev->ap_dev = ap_dev;
 366         zdev->ops = &zcrypt_pcica_ops;
 367         zdev->online = 1;
 368         zdev->user_space_type = ZCRYPT_PCICA;
 369         zdev->type_string = "PCICA";
 370         zdev->min_mod_size = PCICA_MIN_MOD_SIZE;
 371         zdev->max_mod_size = PCICA_MAX_MOD_SIZE;
 372         zdev->speed_rating = PCICA_SPEED_RATING;
 373         zdev->max_exp_bit_length = PCICA_MAX_MOD_SIZE;
 374         ap_dev->reply = &zdev->reply;
 375         ap_dev->private = zdev;
 376         rc = zcrypt_device_register(zdev);
 377         if (rc)
 378                 goto out_free;
 379         return 0;
 380
 381 out_free:
 382         ap_dev->private = NULL;
 383         zcrypt_device_free(zdev);
 384         return rc;
 385 }
 386
 387 /**
 388  * This is called to remove the extended PCICA driver information
 389  * if an AP device is removed.
 390  */
 391 static void zcrypt_pcica_remove(struct ap_device *ap_dev)
 392 {
 393         struct zcrypt_device *zdev = ap_dev->private;
 394
 395         zcrypt_device_unregister(zdev);
 396 }
 397
 398 int __init zcrypt_pcica_init(void)
 399 {
 400         return ap_driver_register(&zcrypt_pcica_driver, THIS_MODULE, "pcica");
 401 }
 402
 403 void zcrypt_pcica_exit(void)
 404 {
 405         ap_driver_unregister(&zcrypt_pcica_driver);
 406 }
 407
 408 module_init(zcrypt_pcica_init);
 409 module_exit(zcrypt_pcica_exit);