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 int 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;
50 n = scatterwalk_copychunks(src, in, bsize, 0);
51 scatterwalk_advance(in, n);
53 desc->prfn(desc, dst, src, bsize);
55 n = scatterwalk_copychunks(dst, out, bsize, 1);
56 scatterwalk_advance(out, n);
61 static inline unsigned int crypt_fast(const struct cipher_desc *desc,
62 struct scatter_walk *in,
63 struct scatter_walk *out,
64 unsigned int nbytes, u8 *tmp)
69 dst = scatterwalk_samebuf(in, out) ? src : out->data;
72 memcpy(tmp, in->data, nbytes);
77 nbytes = desc->prfn(desc, dst, src, nbytes);
80 memcpy(out->data, tmp, nbytes);
82 scatterwalk_advance(in, nbytes);
83 scatterwalk_advance(out, nbytes);
89 * Generic encrypt/decrypt wrapper for ciphers, handles operations across
90 * multiple page boundaries by using temporary blocks. In user context,
91 * the kernel is given a chance to schedule us once per page.
93 static int crypt(const struct cipher_desc *desc,
94 struct scatterlist *dst,
95 struct scatterlist *src,
98 struct scatter_walk walk_in, walk_out;
99 struct crypto_tfm *tfm = desc->tfm;
100 const unsigned int bsize = crypto_tfm_alg_blocksize(tfm);
101 unsigned int alignmask = crypto_tfm_alg_alignmask(tfm);
102 unsigned long buffer = 0;
107 if (nbytes % bsize) {
108 tfm->crt_flags |= CRYPTO_TFM_RES_BAD_BLOCK_LEN;
112 scatterwalk_start(&walk_in, src);
113 scatterwalk_start(&walk_out, dst);
116 unsigned int n = nbytes;
119 if (!scatterwalk_aligned(&walk_in, alignmask) ||
120 !scatterwalk_aligned(&walk_out, alignmask)) {
122 buffer = __get_free_page(GFP_ATOMIC);
129 scatterwalk_map(&walk_in, 0);
130 scatterwalk_map(&walk_out, 1);
132 n = scatterwalk_clamp(&walk_in, n);
133 n = scatterwalk_clamp(&walk_out, n);
135 if (likely(n >= bsize))
136 n = crypt_fast(desc, &walk_in, &walk_out, n, tmp);
138 n = crypt_slow(desc, &walk_in, &walk_out, bsize);
142 scatterwalk_done(&walk_in, 0, nbytes);
143 scatterwalk_done(&walk_out, 1, nbytes);
157 static unsigned int cbc_process_encrypt(const struct cipher_desc *desc,
158 u8 *dst, const u8 *src,
161 struct crypto_tfm *tfm = desc->tfm;
162 void (*xor)(u8 *, const u8 *) = tfm->crt_u.cipher.cit_xor_block;
163 int bsize = crypto_tfm_alg_blocksize(tfm);
165 void (*fn)(void *, u8 *, const u8 *) = desc->crfn;
167 unsigned int done = 0;
171 fn(crypto_tfm_ctx(tfm), dst, iv);
172 memcpy(iv, dst, bsize);
176 } while ((done += bsize) < nbytes);
181 static unsigned int cbc_process_decrypt(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 u8 stack[src == dst ? bsize : 0];
191 u8 **dst_p = src == dst ? &buf : &dst;
193 void (*fn)(void *, u8 *, const u8 *) = desc->crfn;
195 unsigned int done = 0;
198 u8 *tmp_dst = *dst_p;
200 fn(crypto_tfm_ctx(tfm), tmp_dst, src);
202 memcpy(iv, src, bsize);
204 memcpy(dst, tmp_dst, bsize);
208 } while ((done += bsize) < nbytes);
213 static unsigned int ecb_process(const struct cipher_desc *desc, u8 *dst,
214 const u8 *src, unsigned int nbytes)
216 struct crypto_tfm *tfm = desc->tfm;
217 int bsize = crypto_tfm_alg_blocksize(tfm);
218 void (*fn)(void *, u8 *, const u8 *) = desc->crfn;
219 unsigned int done = 0;
222 fn(crypto_tfm_ctx(tfm), dst, src);
226 } while ((done += bsize) < nbytes);
231 static int setkey(struct crypto_tfm *tfm, const u8 *key, unsigned int keylen)
233 struct cipher_alg *cia = &tfm->__crt_alg->cra_cipher;
235 if (keylen < cia->cia_min_keysize || keylen > cia->cia_max_keysize) {
236 tfm->crt_flags |= CRYPTO_TFM_RES_BAD_KEY_LEN;
239 return cia->cia_setkey(crypto_tfm_ctx(tfm), key, keylen,
243 static int ecb_encrypt(struct crypto_tfm *tfm,
244 struct scatterlist *dst,
245 struct scatterlist *src, unsigned int nbytes)
247 struct cipher_desc desc;
248 struct cipher_alg *cipher = &tfm->__crt_alg->cra_cipher;
251 desc.crfn = cipher->cia_encrypt;
252 desc.prfn = cipher->cia_encrypt_ecb ?: ecb_process;
254 return crypt(&desc, dst, src, nbytes);
257 static int ecb_decrypt(struct crypto_tfm *tfm,
258 struct scatterlist *dst,
259 struct scatterlist *src,
262 struct cipher_desc desc;
263 struct cipher_alg *cipher = &tfm->__crt_alg->cra_cipher;
266 desc.crfn = cipher->cia_decrypt;
267 desc.prfn = cipher->cia_decrypt_ecb ?: ecb_process;
269 return crypt(&desc, dst, src, nbytes);
272 static int cbc_encrypt(struct crypto_tfm *tfm,
273 struct scatterlist *dst,
274 struct scatterlist *src,
277 struct cipher_desc desc;
278 struct cipher_alg *cipher = &tfm->__crt_alg->cra_cipher;
281 desc.crfn = cipher->cia_encrypt;
282 desc.prfn = cipher->cia_encrypt_cbc ?: cbc_process_encrypt;
283 desc.info = tfm->crt_cipher.cit_iv;
285 return crypt(&desc, dst, src, nbytes);
288 static int cbc_encrypt_iv(struct crypto_tfm *tfm,
289 struct scatterlist *dst,
290 struct scatterlist *src,
291 unsigned int nbytes, u8 *iv)
293 struct cipher_desc desc;
294 struct cipher_alg *cipher = &tfm->__crt_alg->cra_cipher;
297 desc.crfn = cipher->cia_encrypt;
298 desc.prfn = cipher->cia_encrypt_cbc ?: cbc_process_encrypt;
301 return crypt(&desc, dst, src, nbytes);
304 static int cbc_decrypt(struct crypto_tfm *tfm,
305 struct scatterlist *dst,
306 struct scatterlist *src,
309 struct cipher_desc desc;
310 struct cipher_alg *cipher = &tfm->__crt_alg->cra_cipher;
313 desc.crfn = cipher->cia_decrypt;
314 desc.prfn = cipher->cia_decrypt_cbc ?: cbc_process_decrypt;
315 desc.info = tfm->crt_cipher.cit_iv;
317 return crypt(&desc, dst, src, nbytes);
320 static int cbc_decrypt_iv(struct crypto_tfm *tfm,
321 struct scatterlist *dst,
322 struct scatterlist *src,
323 unsigned int nbytes, u8 *iv)
325 struct cipher_desc desc;
326 struct cipher_alg *cipher = &tfm->__crt_alg->cra_cipher;
329 desc.crfn = cipher->cia_decrypt;
330 desc.prfn = cipher->cia_decrypt_cbc ?: cbc_process_decrypt;
333 return crypt(&desc, dst, src, nbytes);
336 static int nocrypt(struct crypto_tfm *tfm,
337 struct scatterlist *dst,
338 struct scatterlist *src,
344 static int nocrypt_iv(struct crypto_tfm *tfm,
345 struct scatterlist *dst,
346 struct scatterlist *src,
347 unsigned int nbytes, u8 *iv)
352 int crypto_init_cipher_flags(struct crypto_tfm *tfm, u32 flags)
354 u32 mode = flags & CRYPTO_TFM_MODE_MASK;
356 tfm->crt_cipher.cit_mode = mode ? mode : CRYPTO_TFM_MODE_ECB;
357 if (flags & CRYPTO_TFM_REQ_WEAK_KEY)
358 tfm->crt_flags = CRYPTO_TFM_REQ_WEAK_KEY;
363 int crypto_init_cipher_ops(struct crypto_tfm *tfm)
366 struct cipher_tfm *ops = &tfm->crt_cipher;
368 ops->cit_setkey = setkey;
370 switch (tfm->crt_cipher.cit_mode) {
371 case CRYPTO_TFM_MODE_ECB:
372 ops->cit_encrypt = ecb_encrypt;
373 ops->cit_decrypt = ecb_decrypt;
376 case CRYPTO_TFM_MODE_CBC:
377 ops->cit_encrypt = cbc_encrypt;
378 ops->cit_decrypt = cbc_decrypt;
379 ops->cit_encrypt_iv = cbc_encrypt_iv;
380 ops->cit_decrypt_iv = cbc_decrypt_iv;
383 case CRYPTO_TFM_MODE_CFB:
384 ops->cit_encrypt = nocrypt;
385 ops->cit_decrypt = nocrypt;
386 ops->cit_encrypt_iv = nocrypt_iv;
387 ops->cit_decrypt_iv = nocrypt_iv;
390 case CRYPTO_TFM_MODE_CTR:
391 ops->cit_encrypt = nocrypt;
392 ops->cit_decrypt = nocrypt;
393 ops->cit_encrypt_iv = nocrypt_iv;
394 ops->cit_decrypt_iv = nocrypt_iv;
401 if (ops->cit_mode == CRYPTO_TFM_MODE_CBC) {
405 switch (crypto_tfm_alg_blocksize(tfm)) {
407 ops->cit_xor_block = xor_64;
411 ops->cit_xor_block = xor_128;
415 printk(KERN_WARNING "%s: block size %u not supported\n",
416 crypto_tfm_alg_name(tfm),
417 crypto_tfm_alg_blocksize(tfm));
422 ops->cit_ivsize = crypto_tfm_alg_blocksize(tfm);
423 align = crypto_tfm_alg_alignmask(tfm) + 1;
424 addr = (unsigned long)crypto_tfm_ctx(tfm);
425 addr = ALIGN(addr, align);
426 addr += ALIGN(tfm->__crt_alg->cra_ctxsize, align);
427 ops->cit_iv = (void *)addr;
434 void crypto_exit_cipher_ops(struct crypto_tfm *tfm)