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 429