6 * Copyright (c) 2002 James Morris <jmorris@intercode.com.au>
7 * Copyright (c) 2005 Herbert Xu <herbert@gondor.apana.org.au>
9 * This program is free software; you can redistribute it and/or modify it
10 * under the terms of the GNU General Public License as published by the Free
11 * Software Foundation; either version 2 of the License, or (at your option)
15 #include <linux/compiler.h>
16 #include <linux/kernel.h>
17 #include <linux/crypto.h>
18 #include <linux/errno.h>
20 #include <linux/slab.h>
21 #include <linux/string.h>
22 #include <asm/scatterlist.h>
24 #include "scatterwalk.h"
26 static inline void xor_64(u8 *a, const u8 *b)
28 ((u32 *)a)[0] ^= ((u32 *)b)[0];
29 ((u32 *)a)[1] ^= ((u32 *)b)[1];
32 static inline void xor_128(u8 *a, const u8 *b)
34 ((u32 *)a)[0] ^= ((u32 *)b)[0];
35 ((u32 *)a)[1] ^= ((u32 *)b)[1];
36 ((u32 *)a)[2] ^= ((u32 *)b)[2];
37 ((u32 *)a)[3] ^= ((u32 *)b)[3];
40 static unsigned int crypt_slow(const struct cipher_desc *desc,
41 struct scatter_walk *in,
42 struct scatter_walk *out, unsigned int bsize)
44 unsigned long alignmask = crypto_tfm_alg_alignmask(desc->tfm);
45 u8 buffer[bsize * 2 + alignmask];
46 u8 *src = (u8 *)ALIGN((unsigned long)buffer, alignmask + 1);
47 u8 *dst = src + bsize;
49 scatterwalk_copychunks(src, in, bsize, 0);
50 desc->prfn(desc, dst, src, bsize);
51 scatterwalk_copychunks(dst, out, bsize, 1);
56 static inline unsigned int crypt_fast(const struct cipher_desc *desc,
57 struct scatter_walk *in,
58 struct scatter_walk *out,
59 unsigned int nbytes, u8 *tmp)
62 u8 *real_src, *real_dst;
64 real_src = scatterwalk_map(in, 0);
65 real_dst = scatterwalk_map(out, 1);
68 dst = scatterwalk_samebuf(in, out) ? src : real_dst;
71 memcpy(tmp, src, nbytes);
76 nbytes = desc->prfn(desc, dst, src, nbytes);
79 memcpy(real_dst, tmp, nbytes);
81 scatterwalk_unmap(real_src, 0);
82 scatterwalk_unmap(real_dst, 1);
84 scatterwalk_advance(in, nbytes);
85 scatterwalk_advance(out, nbytes);
91 * Generic encrypt/decrypt wrapper for ciphers, handles operations across
92 * multiple page boundaries by using temporary blocks. In user context,
93 * the kernel is given a chance to schedule us once per page.
95 static int crypt(const struct cipher_desc *desc,
96 struct scatterlist *dst,
97 struct scatterlist *src,
100 struct scatter_walk walk_in, walk_out;
101 struct crypto_tfm *tfm = desc->tfm;
102 const unsigned int bsize = crypto_tfm_alg_blocksize(tfm);
103 unsigned int alignmask = crypto_tfm_alg_alignmask(tfm);
104 unsigned long buffer = 0;
109 if (nbytes % bsize) {
110 tfm->crt_flags |= CRYPTO_TFM_RES_BAD_BLOCK_LEN;
114 scatterwalk_start(&walk_in, src);
115 scatterwalk_start(&walk_out, dst);
118 unsigned int n = nbytes;
121 if (!scatterwalk_aligned(&walk_in, alignmask) ||
122 !scatterwalk_aligned(&walk_out, alignmask)) {
124 buffer = __get_free_page(GFP_ATOMIC);
131 n = scatterwalk_clamp(&walk_in, n);
132 n = scatterwalk_clamp(&walk_out, n);
134 if (likely(n >= bsize))
135 n = crypt_fast(desc, &walk_in, &walk_out, n, tmp);
137 n = crypt_slow(desc, &walk_in, &walk_out, bsize);
141 scatterwalk_done(&walk_in, 0, nbytes);
142 scatterwalk_done(&walk_out, 1, nbytes);
147 crypto_yield(tfm->crt_flags);
156 static int crypt_iv_unaligned(struct cipher_desc *desc,
157 struct scatterlist *dst,
158 struct scatterlist *src,
161 struct crypto_tfm *tfm = desc->tfm;
162 unsigned long alignmask = crypto_tfm_alg_alignmask(tfm);
165 if (unlikely(((unsigned long)iv & alignmask))) {
166 unsigned int ivsize = tfm->crt_cipher.cit_ivsize;
167 u8 buffer[ivsize + alignmask];
168 u8 *tmp = (u8 *)ALIGN((unsigned long)buffer, alignmask + 1);
171 desc->info = memcpy(tmp, iv, ivsize);
172 err = crypt(desc, dst, src, nbytes);
173 memcpy(iv, tmp, ivsize);
178 return crypt(desc, dst, src, nbytes);
181 static unsigned int cbc_process_encrypt(const struct cipher_desc *desc,
182 u8 *dst, const u8 *src,
185 struct crypto_tfm *tfm = desc->tfm;
186 void (*xor)(u8 *, const u8 *) = tfm->crt_u.cipher.cit_xor_block;
187 int bsize = crypto_tfm_alg_blocksize(tfm);
189 void (*fn)(struct crypto_tfm *, u8 *, const u8 *) = desc->crfn;
191 unsigned int done = 0;
198 memcpy(iv, dst, bsize);
202 } while ((done += bsize) <= nbytes);
207 static unsigned int cbc_process_decrypt(const struct cipher_desc *desc,
208 u8 *dst, const u8 *src,
211 struct crypto_tfm *tfm = desc->tfm;
212 void (*xor)(u8 *, const u8 *) = tfm->crt_u.cipher.cit_xor_block;
213 int bsize = crypto_tfm_alg_blocksize(tfm);
214 unsigned long alignmask = crypto_tfm_alg_alignmask(desc->tfm);
216 u8 stack[src == dst ? bsize + alignmask : 0];
217 u8 *buf = (u8 *)ALIGN((unsigned long)stack, alignmask + 1);
218 u8 **dst_p = src == dst ? &buf : &dst;
220 void (*fn)(struct crypto_tfm *, u8 *, const u8 *) = desc->crfn;
222 unsigned int done = 0;
227 u8 *tmp_dst = *dst_p;
229 fn(tfm, tmp_dst, src);
231 memcpy(iv, src, bsize);
233 memcpy(dst, tmp_dst, bsize);
237 } while ((done += bsize) <= nbytes);
242 static unsigned int ecb_process(const struct cipher_desc *desc, u8 *dst,
243 const u8 *src, unsigned int nbytes)
245 struct crypto_tfm *tfm = desc->tfm;
246 int bsize = crypto_tfm_alg_blocksize(tfm);
247 void (*fn)(struct crypto_tfm *, u8 *, const u8 *) = desc->crfn;
248 unsigned int done = 0;
257 } while ((done += bsize) <= nbytes);
262 static int setkey(struct crypto_tfm *tfm, const u8 *key, unsigned int keylen)
264 struct cipher_alg *cia = &tfm->__crt_alg->cra_cipher;
266 tfm->crt_flags &= ~CRYPTO_TFM_RES_MASK;
267 if (keylen < cia->cia_min_keysize || keylen > cia->cia_max_keysize) {
268 tfm->crt_flags |= CRYPTO_TFM_RES_BAD_KEY_LEN;
271 return cia->cia_setkey(tfm, key, keylen);
274 static int ecb_encrypt(struct crypto_tfm *tfm,
275 struct scatterlist *dst,
276 struct scatterlist *src, unsigned int nbytes)
278 struct cipher_desc desc;
279 struct cipher_alg *cipher = &tfm->__crt_alg->cra_cipher;
282 desc.crfn = cipher->cia_encrypt;
283 desc.prfn = cipher->cia_encrypt_ecb ?: ecb_process;
285 return crypt(&desc, dst, src, nbytes);
288 static int ecb_decrypt(struct crypto_tfm *tfm,
289 struct scatterlist *dst,
290 struct scatterlist *src,
293 struct cipher_desc desc;
294 struct cipher_alg *cipher = &tfm->__crt_alg->cra_cipher;
297 desc.crfn = cipher->cia_decrypt;
298 desc.prfn = cipher->cia_decrypt_ecb ?: ecb_process;
300 return crypt(&desc, dst, src, nbytes);
303 static int cbc_encrypt(struct crypto_tfm *tfm,
304 struct scatterlist *dst,
305 struct scatterlist *src,
308 struct cipher_desc desc;
309 struct cipher_alg *cipher = &tfm->__crt_alg->cra_cipher;
312 desc.crfn = cipher->cia_encrypt;
313 desc.prfn = cipher->cia_encrypt_cbc ?: cbc_process_encrypt;
314 desc.info = tfm->crt_cipher.cit_iv;
316 return crypt(&desc, dst, src, nbytes);
319 static int cbc_encrypt_iv(struct crypto_tfm *tfm,
320 struct scatterlist *dst,
321 struct scatterlist *src,
322 unsigned int nbytes, u8 *iv)
324 struct cipher_desc desc;
325 struct cipher_alg *cipher = &tfm->__crt_alg->cra_cipher;
328 desc.crfn = cipher->cia_encrypt;
329 desc.prfn = cipher->cia_encrypt_cbc ?: cbc_process_encrypt;
332 return crypt_iv_unaligned(&desc, dst, src, nbytes);
335 static int cbc_decrypt(struct crypto_tfm *tfm,
336 struct scatterlist *dst,
337 struct scatterlist *src,
340 struct cipher_desc desc;
341 struct cipher_alg *cipher = &tfm->__crt_alg->cra_cipher;
344 desc.crfn = cipher->cia_decrypt;
345 desc.prfn = cipher->cia_decrypt_cbc ?: cbc_process_decrypt;
346 desc.info = tfm->crt_cipher.cit_iv;
348 return crypt(&desc, dst, src, nbytes);
351 static int cbc_decrypt_iv(struct crypto_tfm *tfm,
352 struct scatterlist *dst,
353 struct scatterlist *src,
354 unsigned int nbytes, u8 *iv)
356 struct cipher_desc desc;
357 struct cipher_alg *cipher = &tfm->__crt_alg->cra_cipher;
360 desc.crfn = cipher->cia_decrypt;
361 desc.prfn = cipher->cia_decrypt_cbc ?: cbc_process_decrypt;
364 return crypt_iv_unaligned(&desc, dst, src, nbytes);
367 static int nocrypt(struct crypto_tfm *tfm,
368 struct scatterlist *dst,
369 struct scatterlist *src,
375 static int nocrypt_iv(struct crypto_tfm *tfm,
376 struct scatterlist *dst,
377 struct scatterlist *src,
378 unsigned int nbytes, u8 *iv)
383 int crypto_init_cipher_flags(struct crypto_tfm *tfm, u32 flags)
385 u32 mode = flags & CRYPTO_TFM_MODE_MASK;
386 tfm->crt_cipher.cit_mode = mode ? mode : CRYPTO_TFM_MODE_ECB;
390 static void cipher_crypt_unaligned(void (*fn)(struct crypto_tfm *, u8 *,
392 struct crypto_tfm *tfm,
393 u8 *dst, const u8 *src)
395 unsigned long alignmask = crypto_tfm_alg_alignmask(tfm);
396 unsigned int size = crypto_tfm_alg_blocksize(tfm);
397 u8 buffer[size + alignmask];
398 u8 *tmp = (u8 *)ALIGN((unsigned long)buffer, alignmask + 1);
400 memcpy(tmp, src, size);
402 memcpy(dst, tmp, size);
405 static void cipher_encrypt_unaligned(struct crypto_tfm *tfm,
406 u8 *dst, const u8 *src)
408 unsigned long alignmask = crypto_tfm_alg_alignmask(tfm);
409 struct cipher_alg *cipher = &tfm->__crt_alg->cra_cipher;
411 if (unlikely(((unsigned long)dst | (unsigned long)src) & alignmask)) {
412 cipher_crypt_unaligned(cipher->cia_encrypt, tfm, dst, src);
416 cipher->cia_encrypt(tfm, dst, src);
419 static void cipher_decrypt_unaligned(struct crypto_tfm *tfm,
420 u8 *dst, const u8 *src)
422 unsigned long alignmask = crypto_tfm_alg_alignmask(tfm);
423 struct cipher_alg *cipher = &tfm->__crt_alg->cra_cipher;
425 if (unlikely(((unsigned long)dst | (unsigned long)src) & alignmask)) {
426 cipher_crypt_unaligned(cipher->cia_decrypt, tfm, dst, src);
430 cipher->cia_decrypt(tfm, dst, src);
433 int crypto_init_cipher_ops(struct crypto_tfm *tfm)
436 struct cipher_tfm *ops = &tfm->crt_cipher;
437 struct cipher_alg *cipher = &tfm->__crt_alg->cra_cipher;
439 ops->cit_setkey = setkey;
440 ops->cit_encrypt_one = crypto_tfm_alg_alignmask(tfm) ?
441 cipher_encrypt_unaligned : cipher->cia_encrypt;
442 ops->cit_decrypt_one = crypto_tfm_alg_alignmask(tfm) ?
443 cipher_decrypt_unaligned : cipher->cia_decrypt;
445 switch (tfm->crt_cipher.cit_mode) {
446 case CRYPTO_TFM_MODE_ECB:
447 ops->cit_encrypt = ecb_encrypt;
448 ops->cit_decrypt = ecb_decrypt;
449 ops->cit_encrypt_iv = nocrypt_iv;
450 ops->cit_decrypt_iv = nocrypt_iv;
453 case CRYPTO_TFM_MODE_CBC:
454 ops->cit_encrypt = cbc_encrypt;
455 ops->cit_decrypt = cbc_decrypt;
456 ops->cit_encrypt_iv = cbc_encrypt_iv;
457 ops->cit_decrypt_iv = cbc_decrypt_iv;
460 case CRYPTO_TFM_MODE_CFB:
461 ops->cit_encrypt = nocrypt;
462 ops->cit_decrypt = nocrypt;
463 ops->cit_encrypt_iv = nocrypt_iv;
464 ops->cit_decrypt_iv = nocrypt_iv;
467 case CRYPTO_TFM_MODE_CTR:
468 ops->cit_encrypt = nocrypt;
469 ops->cit_decrypt = nocrypt;
470 ops->cit_encrypt_iv = nocrypt_iv;
471 ops->cit_decrypt_iv = nocrypt_iv;
478 if (ops->cit_mode == CRYPTO_TFM_MODE_CBC) {
482 switch (crypto_tfm_alg_blocksize(tfm)) {
484 ops->cit_xor_block = xor_64;
488 ops->cit_xor_block = xor_128;
492 printk(KERN_WARNING "%s: block size %u not supported\n",
493 crypto_tfm_alg_name(tfm),
494 crypto_tfm_alg_blocksize(tfm));
499 ops->cit_ivsize = crypto_tfm_alg_blocksize(tfm);
500 align = crypto_tfm_alg_alignmask(tfm) + 1;
501 addr = (unsigned long)crypto_tfm_ctx(tfm);
502 addr = ALIGN(addr, align);
503 addr += ALIGN(tfm->__crt_alg->cra_ctxsize, align);
504 ops->cit_iv = (void *)addr;
511 void crypto_exit_cipher_ops(struct crypto_tfm *tfm)