| 1 | /****************************************************************************** |
| 2 | ** |
| 3 | ** FILE NAME : ifxmips_arc4.c |
| 4 | ** PROJECT : IFX UEIP |
| 5 | ** MODULES : DEU Module |
| 6 | ** |
| 7 | ** DATE : September 8, 2009 |
| 8 | ** AUTHOR : Mohammad Firdaus |
| 9 | ** DESCRIPTION : Data Encryption Unit Driver for ARC4 Algorithm |
| 10 | ** COPYRIGHT : Copyright (c) 2009 |
| 11 | ** Infineon Technologies AG |
| 12 | ** Am Campeon 1-12, 85579 Neubiberg, Germany |
| 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 of the License, or |
| 17 | ** (at your option) any later version. |
| 18 | ** |
| 19 | ** HISTORY |
| 20 | ** $Date $Author $Comment |
| 21 | ** 08 Sept 2009 Mohammad Firdaus Initial UEIP release |
| 22 | *******************************************************************************/ |
| 23 | |
| 24 | /*! |
| 25 | \defgroup IFX_DEU IFX_DEU_DRIVERS |
| 26 | \ingroup API |
| 27 | \brief ifx deu driver module |
| 28 | */ |
| 29 | |
| 30 | /*! |
| 31 | \file ifxmips_arc4.c |
| 32 | \ingroup IFX_DEU |
| 33 | \brief ARC4 encryption DEU driver file |
| 34 | */ |
| 35 | |
| 36 | /*! |
| 37 | \defgroup IFX_ARC4_FUNCTIONS IFX_ARC4_FUNCTIONS |
| 38 | \ingroup IFX_DEU |
| 39 | \brief IFX deu driver functions |
| 40 | */ |
| 41 | |
| 42 | /* Project header */ |
| 43 | #include <linux/version.h> |
| 44 | #include <linux/module.h> |
| 45 | #include <linux/init.h> |
| 46 | #include <linux/types.h> |
| 47 | #include <linux/errno.h> |
| 48 | #include <linux/crypto.h> |
| 49 | #include <crypto/algapi.h> |
| 50 | #include <linux/interrupt.h> |
| 51 | #include <asm/byteorder.h> |
| 52 | #include <linux/delay.h> |
| 53 | |
| 54 | /* Board specific header files */ |
| 55 | #ifdef CONFIG_AR9 |
| 56 | #include "ifxmips_deu_ar9.h" |
| 57 | #endif |
| 58 | #ifdef CONFIG_VR9 |
| 59 | #include "ifxmips_deu_vr9.h" |
| 60 | #endif |
| 61 | |
| 62 | static spinlock_t lock; |
| 63 | #define CRTCL_SECT_INIT spin_lock_init(&lock) |
| 64 | #define CRTCL_SECT_START spin_lock_irqsave(&lock, flag) |
| 65 | #define CRTCL_SECT_END spin_unlock_irqrestore(&lock, flag) |
| 66 | |
| 67 | /* Preprocessor declerations */ |
| 68 | #define ARC4_MIN_KEY_SIZE 1 |
| 69 | //#define ARC4_MAX_KEY_SIZE 256 |
| 70 | #define ARC4_MAX_KEY_SIZE 16 |
| 71 | #define ARC4_BLOCK_SIZE 1 |
| 72 | #define ARC4_START IFX_ARC4_CON |
| 73 | #ifdef CRYPTO_DEBUG |
| 74 | extern char debug_level; |
| 75 | #define DPRINTF(level, format, args...) if (level < debug_level) printk(KERN_INFO "[%s %s %d]: " format, __FILE__, __func__, __LINE__, ##args); |
| 76 | #else |
| 77 | #define DPRINTF(level, format, args...) |
| 78 | #endif |
| 79 | |
| 80 | /* |
| 81 | * \brief arc4 private structure |
| 82 | */ |
| 83 | struct arc4_ctx { |
| 84 | int key_length; |
| 85 | u8 buf[120]; |
| 86 | }; |
| 87 | |
| 88 | extern int disable_deudma; |
| 89 | extern int disable_multiblock; |
| 90 | |
| 91 | |
| 92 | /*! \fn static void _deu_arc4 (void *ctx_arg, u8 *out_arg, const u8 *in_arg, u8 *iv_arg, u32 nbytes, int encdec, int mode) |
| 93 | \ingroup IFX_ARC4_FUNCTIONS |
| 94 | \brief main interface to ARC4 hardware |
| 95 | \param ctx_arg crypto algo context |
| 96 | \param out_arg output bytestream |
| 97 | \param in_arg input bytestream |
| 98 | \param iv_arg initialization vector |
| 99 | \param nbytes length of bytestream |
| 100 | \param encdec 1 for encrypt; 0 for decrypt |
| 101 | \param mode operation mode such as ebc, cbc, ctr |
| 102 | */ |
| 103 | static void _deu_arc4 (void *ctx_arg, u8 *out_arg, const u8 *in_arg, |
| 104 | u8 *iv_arg, u32 nbytes, int encdec, int mode) |
| 105 | { |
| 106 | volatile struct arc4_t *arc4 = (struct arc4_t *) ARC4_START; |
| 107 | |
| 108 | int i = 0; |
| 109 | unsigned long flag; |
| 110 | |
| 111 | #if 1 // need to handle nbytes not multiple of 16 |
| 112 | volatile u32 tmp_array32[4]; |
| 113 | volatile u8 *tmp_ptr8; |
| 114 | int remaining_bytes, j; |
| 115 | #endif |
| 116 | |
| 117 | CRTCL_SECT_START; |
| 118 | |
| 119 | arc4->IDLEN = nbytes; |
| 120 | |
| 121 | #if 1 |
| 122 | while (i < nbytes) { |
| 123 | arc4->ID3R = *((u32 *) in_arg + (i>>2) + 0); |
| 124 | arc4->ID2R = *((u32 *) in_arg + (i>>2) + 1); |
| 125 | arc4->ID1R = *((u32 *) in_arg + (i>>2) + 2); |
| 126 | arc4->ID0R = *((u32 *) in_arg + (i>>2) + 3); |
| 127 | |
| 128 | arc4->controlr.GO = 1; |
| 129 | |
| 130 | while (arc4->controlr.BUS) { |
| 131 | // this will not take long |
| 132 | } |
| 133 | |
| 134 | #if 1 |
| 135 | // need to handle nbytes not multiple of 16 |
| 136 | tmp_array32[0] = arc4->OD3R; |
| 137 | tmp_array32[1] = arc4->OD2R; |
| 138 | tmp_array32[2] = arc4->OD1R; |
| 139 | tmp_array32[3] = arc4->OD0R; |
| 140 | |
| 141 | remaining_bytes = nbytes - i; |
| 142 | if (remaining_bytes > 16) |
| 143 | remaining_bytes = 16; |
| 144 | |
| 145 | tmp_ptr8 = (u8 *)&tmp_array32[0]; |
| 146 | for (j = 0; j < remaining_bytes; j++) |
| 147 | *out_arg++ = *tmp_ptr8++; |
| 148 | #else |
| 149 | *((u32 *) out_arg + (i>>2) + 0) = arc4->OD3R; |
| 150 | *((u32 *) out_arg + (i>>2) + 1) = arc4->OD2R; |
| 151 | *((u32 *) out_arg + (i>>2) + 2) = arc4->OD1R; |
| 152 | *((u32 *) out_arg + (i>>2) + 3) = arc4->OD0R; |
| 153 | #endif |
| 154 | |
| 155 | i += 16; |
| 156 | } |
| 157 | #else // dma |
| 158 | |
| 159 | #endif // dma |
| 160 | |
| 161 | CRTCL_SECT_END; |
| 162 | } |
| 163 | |
| 164 | /*! \fn arc4_chip_init (void) |
| 165 | \ingroup IFX_ARC4_FUNCTIONS |
| 166 | \brief initialize arc4 hardware |
| 167 | */ |
| 168 | static void arc4_chip_init (void) |
| 169 | { |
| 170 | //do nothing |
| 171 | } |
| 172 | |
| 173 | /*! \fn static int arc4_set_key(struct crypto_tfm *tfm, const u8 *in_key, unsigned int key_len) |
| 174 | \ingroup IFX_ARC4_FUNCTIONS |
| 175 | \brief sets ARC4 key |
| 176 | \param tfm linux crypto algo transform |
| 177 | \param in_key input key |
| 178 | \param key_len key lengths less than or equal to 16 bytes supported |
| 179 | */ |
| 180 | static int arc4_set_key(struct crypto_tfm *tfm, const u8 *inkey, |
| 181 | unsigned int key_len) |
| 182 | { |
| 183 | //struct arc4_ctx *ctx = crypto_tfm_ctx(tfm); |
| 184 | volatile struct arc4_t *arc4 = (struct arc4_t *) ARC4_START; |
| 185 | u32 *in_key = (u32 *)inkey; |
| 186 | |
| 187 | // must program all bits at one go?!!! |
| 188 | //#if 1 |
| 189 | *IFX_ARC4_CON = ( (1<<31) | ((key_len - 1)<<27) | (1<<26) | (3<<16) ); |
| 190 | //NDC=1,ENDI=1,GO=0,KSAE=1,SM=0 |
| 191 | |
| 192 | arc4->K3R = *((u32 *) in_key + 0); |
| 193 | arc4->K2R = *((u32 *) in_key + 1); |
| 194 | arc4->K1R = *((u32 *) in_key + 2); |
| 195 | arc4->K0R = *((u32 *) in_key + 3); |
| 196 | |
| 197 | #if 0 // arc4 is a ugly state machine, KSAE can only be set once per session |
| 198 | ctx->key_length = key_len; |
| 199 | |
| 200 | memcpy ((u8 *) (ctx->buf), in_key, key_len); |
| 201 | #endif |
| 202 | |
| 203 | return 0; |
| 204 | } |
| 205 | |
| 206 | /*! \fn static void _deu_arc4_ecb(void *ctx, uint8_t *dst, const uint8_t *src, uint8_t *iv, size_t nbytes, int encdec, int inplace) |
| 207 | \ingroup IFX_ARC4_FUNCTIONS |
| 208 | \brief sets ARC4 hardware to ECB mode |
| 209 | \param ctx crypto algo context |
| 210 | \param dst output bytestream |
| 211 | \param src input bytestream |
| 212 | \param iv initialization vector |
| 213 | \param nbytes length of bytestream |
| 214 | \param encdec 1 for encrypt; 0 for decrypt |
| 215 | \param inplace not used |
| 216 | */ |
| 217 | static void _deu_arc4_ecb(void *ctx, uint8_t *dst, const uint8_t *src, |
| 218 | uint8_t *iv, size_t nbytes, int encdec, int inplace) |
| 219 | { |
| 220 | _deu_arc4 (ctx, dst, src, NULL, nbytes, encdec, 0); |
| 221 | } |
| 222 | |
| 223 | /*! \fn static void arc4_crypt(struct crypto_tfm *tfm, u8 *out, const u8 *in) |
| 224 | \ingroup IFX_ARC4_FUNCTIONS |
| 225 | \brief encrypt/decrypt ARC4_BLOCK_SIZE of data |
| 226 | \param tfm linux crypto algo transform |
| 227 | \param out output bytestream |
| 228 | \param in input bytestream |
| 229 | */ |
| 230 | static void arc4_crypt(struct crypto_tfm *tfm, u8 *out, const u8 *in) |
| 231 | { |
| 232 | struct arc4_ctx *ctx = crypto_tfm_ctx(tfm); |
| 233 | |
| 234 | _deu_arc4 (ctx, out, in, NULL, ARC4_BLOCK_SIZE, |
| 235 | CRYPTO_DIR_DECRYPT, 0); |
| 236 | |
| 237 | } |
| 238 | |
| 239 | /* |
| 240 | * \brief ARC4 function mappings |
| 241 | */ |
| 242 | static struct crypto_alg ifxdeu_arc4_alg = { |
| 243 | .cra_name = "arc4", |
| 244 | .cra_driver_name = "ifxdeu-arc4", |
| 245 | .cra_flags = CRYPTO_ALG_TYPE_CIPHER, |
| 246 | .cra_blocksize = ARC4_BLOCK_SIZE, |
| 247 | .cra_ctxsize = sizeof(struct arc4_ctx), |
| 248 | .cra_module = THIS_MODULE, |
| 249 | .cra_list = LIST_HEAD_INIT(ifxdeu_arc4_alg.cra_list), |
| 250 | .cra_u = { |
| 251 | .cipher = { |
| 252 | .cia_min_keysize = ARC4_MIN_KEY_SIZE, |
| 253 | .cia_max_keysize = ARC4_MAX_KEY_SIZE, |
| 254 | .cia_setkey = arc4_set_key, |
| 255 | .cia_encrypt = arc4_crypt, |
| 256 | .cia_decrypt = arc4_crypt, |
| 257 | } |
| 258 | } |
| 259 | }; |
| 260 | |
| 261 | /*! \fn static int ecb_arc4_encrypt(struct blkcipher_desc *desc, struct scatterlist *dst, struct scatterlist *src, unsigned int nbytes) |
| 262 | \ingroup IFX_ARC4_FUNCTIONS |
| 263 | \brief ECB ARC4 encrypt using linux crypto blkcipher |
| 264 | \param desc blkcipher descriptor |
| 265 | \param dst output scatterlist |
| 266 | \param src input scatterlist |
| 267 | \param nbytes data size in bytes |
| 268 | */ |
| 269 | static int ecb_arc4_encrypt(struct blkcipher_desc *desc, |
| 270 | struct scatterlist *dst, struct scatterlist *src, |
| 271 | unsigned int nbytes) |
| 272 | { |
| 273 | struct arc4_ctx *ctx = crypto_blkcipher_ctx(desc->tfm); |
| 274 | struct blkcipher_walk walk; |
| 275 | int err; |
| 276 | |
| 277 | DPRINTF(1, "\n"); |
| 278 | blkcipher_walk_init(&walk, dst, src, nbytes); |
| 279 | err = blkcipher_walk_virt(desc, &walk); |
| 280 | |
| 281 | while ((nbytes = walk.nbytes)) { |
| 282 | _deu_arc4_ecb(ctx, walk.dst.virt.addr, walk.src.virt.addr, |
| 283 | NULL, nbytes, CRYPTO_DIR_ENCRYPT, 0); |
| 284 | nbytes &= ARC4_BLOCK_SIZE - 1; |
| 285 | err = blkcipher_walk_done(desc, &walk, nbytes); |
| 286 | } |
| 287 | |
| 288 | return err; |
| 289 | } |
| 290 | |
| 291 | /*! \fn static int ecb_arc4_decrypt(struct blkcipher_desc *desc, struct scatterlist *dst, struct scatterlist *src, unsigned int nbytes) |
| 292 | \ingroup IFX_ARC4_FUNCTIONS |
| 293 | \brief ECB ARC4 decrypt using linux crypto blkcipher |
| 294 | \param desc blkcipher descriptor |
| 295 | \param dst output scatterlist |
| 296 | \param src input scatterlist |
| 297 | \param nbytes data size in bytes |
| 298 | */ |
| 299 | static int ecb_arc4_decrypt(struct blkcipher_desc *desc, |
| 300 | struct scatterlist *dst, struct scatterlist *src, |
| 301 | unsigned int nbytes) |
| 302 | { |
| 303 | struct arc4_ctx *ctx = crypto_blkcipher_ctx(desc->tfm); |
| 304 | struct blkcipher_walk walk; |
| 305 | int err; |
| 306 | |
| 307 | DPRINTF(1, "\n"); |
| 308 | blkcipher_walk_init(&walk, dst, src, nbytes); |
| 309 | err = blkcipher_walk_virt(desc, &walk); |
| 310 | |
| 311 | while ((nbytes = walk.nbytes)) { |
| 312 | _deu_arc4_ecb(ctx, walk.dst.virt.addr, walk.src.virt.addr, |
| 313 | NULL, nbytes, CRYPTO_DIR_DECRYPT, 0); |
| 314 | nbytes &= ARC4_BLOCK_SIZE - 1; |
| 315 | err = blkcipher_walk_done(desc, &walk, nbytes); |
| 316 | } |
| 317 | |
| 318 | return err; |
| 319 | } |
| 320 | |
| 321 | /* |
| 322 | * \brief ARC4 function mappings |
| 323 | */ |
| 324 | static struct crypto_alg ifxdeu_ecb_arc4_alg = { |
| 325 | .cra_name = "ecb(arc4)", |
| 326 | .cra_driver_name = "ifxdeu-ecb(arc4)", |
| 327 | .cra_flags = CRYPTO_ALG_TYPE_BLKCIPHER, |
| 328 | .cra_blocksize = ARC4_BLOCK_SIZE, |
| 329 | .cra_ctxsize = sizeof(struct arc4_ctx), |
| 330 | .cra_type = &crypto_blkcipher_type, |
| 331 | .cra_module = THIS_MODULE, |
| 332 | .cra_list = LIST_HEAD_INIT(ifxdeu_ecb_arc4_alg.cra_list), |
| 333 | .cra_u = { |
| 334 | .blkcipher = { |
| 335 | .min_keysize = ARC4_MIN_KEY_SIZE, |
| 336 | .max_keysize = ARC4_MAX_KEY_SIZE, |
| 337 | .setkey = arc4_set_key, |
| 338 | .encrypt = ecb_arc4_encrypt, |
| 339 | .decrypt = ecb_arc4_decrypt, |
| 340 | } |
| 341 | } |
| 342 | }; |
| 343 | |
| 344 | /*! \fn int __init ifxdeu_init_arc4(void) |
| 345 | \ingroup IFX_ARC4_FUNCTIONS |
| 346 | \brief initialize arc4 driver |
| 347 | */ |
| 348 | int __init ifxdeu_init_arc4(void) |
| 349 | { |
| 350 | int ret = -ENOSYS; |
| 351 | |
| 352 | |
| 353 | if ((ret = crypto_register_alg(&ifxdeu_arc4_alg))) |
| 354 | goto arc4_err; |
| 355 | |
| 356 | if ((ret = crypto_register_alg(&ifxdeu_ecb_arc4_alg))) |
| 357 | goto ecb_arc4_err; |
| 358 | |
| 359 | arc4_chip_init (); |
| 360 | |
| 361 | CRTCL_SECT_INIT; |
| 362 | |
| 363 | printk (KERN_NOTICE "IFX DEU ARC4 initialized%s%s.\n", disable_multiblock ? "" : " (multiblock)", disable_deudma ? "" : " (DMA)"); |
| 364 | return ret; |
| 365 | |
| 366 | arc4_err: |
| 367 | crypto_unregister_alg(&ifxdeu_arc4_alg); |
| 368 | printk(KERN_ERR "IFX arc4 initialization failed!\n"); |
| 369 | return ret; |
| 370 | ecb_arc4_err: |
| 371 | crypto_unregister_alg(&ifxdeu_ecb_arc4_alg); |
| 372 | printk (KERN_ERR "IFX ecb_arc4 initialization failed!\n"); |
| 373 | return ret; |
| 374 | |
| 375 | } |
| 376 | |
| 377 | /*! \fn void __exit ifxdeu_fini_arc4(void) |
| 378 | \ingroup IFX_ARC4_FUNCTIONS |
| 379 | \brief unregister arc4 driver |
| 380 | */ |
| 381 | void __exit ifxdeu_fini_arc4(void) |
| 382 | { |
| 383 | crypto_unregister_alg (&ifxdeu_arc4_alg); |
| 384 | crypto_unregister_alg (&ifxdeu_ecb_arc4_alg); |
| 385 | |
| 386 | |
| 387 | } |
| 388 | |
| 389 | |
| 390 | |
