dma-debug: Fix the overlap() function to be correct and readable
[linux-2.6.git] / crypto / cipher.c
index 6926449..9a1a731 100644 (file)
@@ -4,6 +4,7 @@
  * Cipher operations.
  *
  * Copyright (c) 2002 James Morris <jmorris@intercode.com.au>
+ * Copyright (c) 2005 Herbert Xu <herbert@gondor.apana.org.au>
  *
  * This program is free software; you can redistribute it and/or modify it
  * under the terms of the GNU General Public License as published by the Free
  * any later version.
  *
  */
-#include <linux/compiler.h>
+
 #include <linux/kernel.h>
 #include <linux/crypto.h>
 #include <linux/errno.h>
-#include <linux/mm.h>
 #include <linux/slab.h>
 #include <linux/string.h>
-#include <asm/scatterlist.h>
 #include "internal.h"
-#include "scatterwalk.h"
-
-typedef void (cryptfn_t)(void *, u8 *, const u8 *);
-typedef void (procfn_t)(struct crypto_tfm *, u8 *,
-                        u8*, cryptfn_t, void *);
-
-static inline void xor_64(u8 *a, const u8 *b)
-{
-       ((u32 *)a)[0] ^= ((u32 *)b)[0];
-       ((u32 *)a)[1] ^= ((u32 *)b)[1];
-}
-
-static inline void xor_128(u8 *a, const u8 *b)
-{
-       ((u32 *)a)[0] ^= ((u32 *)b)[0];
-       ((u32 *)a)[1] ^= ((u32 *)b)[1];
-       ((u32 *)a)[2] ^= ((u32 *)b)[2];
-       ((u32 *)a)[3] ^= ((u32 *)b)[3];
-}
-static inline void *prepare_src(struct scatter_walk *walk, int bsize,
-                               void *tmp, int in_place)
-{
-       void *src = walk->data;
-       int n = bsize;
-
-       if (unlikely(scatterwalk_across_pages(walk, bsize))) {
-               src = tmp;
-               n = scatterwalk_copychunks(src, walk, bsize, 0);
-       }
-       scatterwalk_advance(walk, n);
-       return src;
-}
-
-static inline void *prepare_dst(struct scatter_walk *walk, int bsize,
-                               void *tmp, int in_place)
-{
-       void *dst = walk->data;
-
-       if (unlikely(scatterwalk_across_pages(walk, bsize)) || in_place)
-               dst = tmp;
-       return dst;
-}
-
-static inline void complete_src(struct scatter_walk *walk, int bsize,
-                               void *src, int in_place)
-{
-}
-
-static inline void complete_dst(struct scatter_walk *walk, int bsize,
-                               void *dst, int in_place)
-{
-       int n = bsize;
-
-       if (unlikely(scatterwalk_across_pages(walk, bsize)))
-               n = scatterwalk_copychunks(dst, walk, bsize, 1);
-       else if (in_place)
-               memcpy(walk->data, dst, bsize);
-       scatterwalk_advance(walk, n);
-}
-
-/* 
- * Generic encrypt/decrypt wrapper for ciphers, handles operations across
- * multiple page boundaries by using temporary blocks.  In user context,
- * the kernel is given a chance to schedule us once per block.
- */
-static int crypt(struct crypto_tfm *tfm,
-                struct scatterlist *dst,
-                struct scatterlist *src,
-                 unsigned int nbytes, cryptfn_t crfn,
-                 procfn_t prfn, void *info)
-{
-       struct scatter_walk walk_in, walk_out;
-       const unsigned int bsize = crypto_tfm_alg_blocksize(tfm);
-       u8 tmp_src[bsize];
-       u8 tmp_dst[bsize];
-
-       if (!nbytes)
-               return 0;
-
-       if (nbytes % bsize) {
-               tfm->crt_flags |= CRYPTO_TFM_RES_BAD_BLOCK_LEN;
-               return -EINVAL;
-       }
-
-       scatterwalk_start(&walk_in, src);
-       scatterwalk_start(&walk_out, dst);
-
-       for(;;) {
-               u8 *src_p, *dst_p;
-               int in_place;
-
-               scatterwalk_map(&walk_in, 0);
-               scatterwalk_map(&walk_out, 1);
-
-               in_place = scatterwalk_samebuf(&walk_in, &walk_out);
-
-               do {
-                       src_p = prepare_src(&walk_in, bsize, tmp_src,
-                                           in_place);
-                       dst_p = prepare_dst(&walk_out, bsize, tmp_dst,
-                                           in_place);
-
-                       prfn(tfm, dst_p, src_p, crfn, info);
-
-                       complete_src(&walk_in, bsize, src_p, in_place);
-                       complete_dst(&walk_out, bsize, dst_p, in_place);
-
-                       nbytes -= bsize;
-               } while (nbytes &&
-                        !scatterwalk_across_pages(&walk_in, bsize) &&
-                        !scatterwalk_across_pages(&walk_out, bsize));
 
-               scatterwalk_done(&walk_in, 0, nbytes);
-               scatterwalk_done(&walk_out, 1, nbytes);
-
-               if (!nbytes)
-                       return 0;
-
-               crypto_yield(tfm);
-       }
-}
-
-static void cbc_process_encrypt(struct crypto_tfm *tfm, u8 *dst, u8 *src,
-                               cryptfn_t fn, void *info)
+static int setkey_unaligned(struct crypto_tfm *tfm, const u8 *key,
+                           unsigned int keylen)
 {
-       u8 *iv = info;
-
-       tfm->crt_u.cipher.cit_xor_block(iv, src);
-       fn(crypto_tfm_ctx(tfm), dst, iv);
-       memcpy(iv, dst, crypto_tfm_alg_blocksize(tfm));
-}
-
-static void cbc_process_decrypt(struct crypto_tfm *tfm, u8 *dst, u8 *src,
-                               cryptfn_t fn, void *info)
-{
-       u8 *iv = info;
-
-       fn(crypto_tfm_ctx(tfm), dst, src);
-       tfm->crt_u.cipher.cit_xor_block(dst, iv);
-       memcpy(iv, src, crypto_tfm_alg_blocksize(tfm));
-}
+       struct cipher_alg *cia = &tfm->__crt_alg->cra_cipher;
+       unsigned long alignmask = crypto_tfm_alg_alignmask(tfm);
+       int ret;
+       u8 *buffer, *alignbuffer;
+       unsigned long absize;
+
+       absize = keylen + alignmask;
+       buffer = kmalloc(absize, GFP_ATOMIC);
+       if (!buffer)
+               return -ENOMEM;
+
+       alignbuffer = (u8 *)ALIGN((unsigned long)buffer, alignmask + 1);
+       memcpy(alignbuffer, key, keylen);
+       ret = cia->cia_setkey(tfm, alignbuffer, keylen);
+       memset(alignbuffer, 0, keylen);
+       kfree(buffer);
+       return ret;
 
-static void ecb_process(struct crypto_tfm *tfm, u8 *dst, u8 *src,
-                       cryptfn_t fn, void *info)
-{
-       fn(crypto_tfm_ctx(tfm), dst, src);
 }
 
 static int setkey(struct crypto_tfm *tfm, const u8 *key, unsigned int keylen)
 {
        struct cipher_alg *cia = &tfm->__crt_alg->cra_cipher;
-       
+       unsigned long alignmask = crypto_tfm_alg_alignmask(tfm);
+
+       tfm->crt_flags &= ~CRYPTO_TFM_RES_MASK;
        if (keylen < cia->cia_min_keysize || keylen > cia->cia_max_keysize) {
                tfm->crt_flags |= CRYPTO_TFM_RES_BAD_KEY_LEN;
                return -EINVAL;
-       } else
-               return cia->cia_setkey(crypto_tfm_ctx(tfm), key, keylen,
-                                      &tfm->crt_flags);
-}
+       }
 
-static int ecb_encrypt(struct crypto_tfm *tfm,
-                      struct scatterlist *dst,
-                       struct scatterlist *src, unsigned int nbytes)
-{
-       return crypt(tfm, dst, src, nbytes,
-                    tfm->__crt_alg->cra_cipher.cia_encrypt,
-                    ecb_process, NULL);
-}
+       if ((unsigned long)key & alignmask)
+               return setkey_unaligned(tfm, key, keylen);
 
-static int ecb_decrypt(struct crypto_tfm *tfm,
-                       struct scatterlist *dst,
-                       struct scatterlist *src,
-                      unsigned int nbytes)
-{
-       return crypt(tfm, dst, src, nbytes,
-                    tfm->__crt_alg->cra_cipher.cia_decrypt,
-                    ecb_process, NULL);
+       return cia->cia_setkey(tfm, key, keylen);
 }
 
-static int cbc_encrypt(struct crypto_tfm *tfm,
-                       struct scatterlist *dst,
-                       struct scatterlist *src,
-                      unsigned int nbytes)
+static void cipher_crypt_unaligned(void (*fn)(struct crypto_tfm *, u8 *,
+                                             const u8 *),
+                                  struct crypto_tfm *tfm,
+                                  u8 *dst, const u8 *src)
 {
-       return crypt(tfm, dst, src, nbytes,
-                    tfm->__crt_alg->cra_cipher.cia_encrypt,
-                    cbc_process_encrypt, tfm->crt_cipher.cit_iv);
-}
+       unsigned long alignmask = crypto_tfm_alg_alignmask(tfm);
+       unsigned int size = crypto_tfm_alg_blocksize(tfm);
+       u8 buffer[size + alignmask];
+       u8 *tmp = (u8 *)ALIGN((unsigned long)buffer, alignmask + 1);
 
-static int cbc_encrypt_iv(struct crypto_tfm *tfm,
-                          struct scatterlist *dst,
-                          struct scatterlist *src,
-                          unsigned int nbytes, u8 *iv)
-{
-       return crypt(tfm, dst, src, nbytes,
-                    tfm->__crt_alg->cra_cipher.cia_encrypt,
-                    cbc_process_encrypt, iv);
+       memcpy(tmp, src, size);
+       fn(tfm, tmp, tmp);
+       memcpy(dst, tmp, size);
 }
 
-static int cbc_decrypt(struct crypto_tfm *tfm,
-                       struct scatterlist *dst,
-                       struct scatterlist *src,
-                      unsigned int nbytes)
+static void cipher_encrypt_unaligned(struct crypto_tfm *tfm,
+                                    u8 *dst, const u8 *src)
 {
-       return crypt(tfm, dst, src, nbytes,
-                    tfm->__crt_alg->cra_cipher.cia_decrypt,
-                    cbc_process_decrypt, tfm->crt_cipher.cit_iv);
-}
+       unsigned long alignmask = crypto_tfm_alg_alignmask(tfm);
+       struct cipher_alg *cipher = &tfm->__crt_alg->cra_cipher;
 
-static int cbc_decrypt_iv(struct crypto_tfm *tfm,
-                          struct scatterlist *dst,
-                          struct scatterlist *src,
-                          unsigned int nbytes, u8 *iv)
-{
-       return crypt(tfm, dst, src, nbytes,
-                    tfm->__crt_alg->cra_cipher.cia_decrypt,
-                    cbc_process_decrypt, iv);
-}
+       if (unlikely(((unsigned long)dst | (unsigned long)src) & alignmask)) {
+               cipher_crypt_unaligned(cipher->cia_encrypt, tfm, dst, src);
+               return;
+       }
 
-static int nocrypt(struct crypto_tfm *tfm,
-                   struct scatterlist *dst,
-                   struct scatterlist *src,
-                  unsigned int nbytes)
-{
-       return -ENOSYS;
+       cipher->cia_encrypt(tfm, dst, src);
 }
 
-static int nocrypt_iv(struct crypto_tfm *tfm,
-                      struct scatterlist *dst,
-                      struct scatterlist *src,
-                      unsigned int nbytes, u8 *iv)
+static void cipher_decrypt_unaligned(struct crypto_tfm *tfm,
+                                    u8 *dst, const u8 *src)
 {
-       return -ENOSYS;
-}
+       unsigned long alignmask = crypto_tfm_alg_alignmask(tfm);
+       struct cipher_alg *cipher = &tfm->__crt_alg->cra_cipher;
 
-int crypto_init_cipher_flags(struct crypto_tfm *tfm, u32 flags)
-{
-       u32 mode = flags & CRYPTO_TFM_MODE_MASK;
-       
-       tfm->crt_cipher.cit_mode = mode ? mode : CRYPTO_TFM_MODE_ECB;
-       if (flags & CRYPTO_TFM_REQ_WEAK_KEY)
-               tfm->crt_flags = CRYPTO_TFM_REQ_WEAK_KEY;
-       
-       return 0;
+       if (unlikely(((unsigned long)dst | (unsigned long)src) & alignmask)) {
+               cipher_crypt_unaligned(cipher->cia_decrypt, tfm, dst, src);
+               return;
+       }
+
+       cipher->cia_decrypt(tfm, dst, src);
 }
 
 int crypto_init_cipher_ops(struct crypto_tfm *tfm)
 {
-       int ret = 0;
        struct cipher_tfm *ops = &tfm->crt_cipher;
+       struct cipher_alg *cipher = &tfm->__crt_alg->cra_cipher;
 
        ops->cit_setkey = setkey;
+       ops->cit_encrypt_one = crypto_tfm_alg_alignmask(tfm) ?
+               cipher_encrypt_unaligned : cipher->cia_encrypt;
+       ops->cit_decrypt_one = crypto_tfm_alg_alignmask(tfm) ?
+               cipher_decrypt_unaligned : cipher->cia_decrypt;
 
-       switch (tfm->crt_cipher.cit_mode) {
-       case CRYPTO_TFM_MODE_ECB:
-               ops->cit_encrypt = ecb_encrypt;
-               ops->cit_decrypt = ecb_decrypt;
-               break;
-               
-       case CRYPTO_TFM_MODE_CBC:
-               ops->cit_encrypt = cbc_encrypt;
-               ops->cit_decrypt = cbc_decrypt;
-               ops->cit_encrypt_iv = cbc_encrypt_iv;
-               ops->cit_decrypt_iv = cbc_decrypt_iv;
-               break;
-               
-       case CRYPTO_TFM_MODE_CFB:
-               ops->cit_encrypt = nocrypt;
-               ops->cit_decrypt = nocrypt;
-               ops->cit_encrypt_iv = nocrypt_iv;
-               ops->cit_decrypt_iv = nocrypt_iv;
-               break;
-       
-       case CRYPTO_TFM_MODE_CTR:
-               ops->cit_encrypt = nocrypt;
-               ops->cit_decrypt = nocrypt;
-               ops->cit_encrypt_iv = nocrypt_iv;
-               ops->cit_decrypt_iv = nocrypt_iv;
-               break;
-
-       default:
-               BUG();
-       }
-       
-       if (ops->cit_mode == CRYPTO_TFM_MODE_CBC) {
-               
-               switch (crypto_tfm_alg_blocksize(tfm)) {
-               case 8:
-                       ops->cit_xor_block = xor_64;
-                       break;
-                       
-               case 16:
-                       ops->cit_xor_block = xor_128;
-                       break;
-                       
-               default:
-                       printk(KERN_WARNING "%s: block size %u not supported\n",
-                              crypto_tfm_alg_name(tfm),
-                              crypto_tfm_alg_blocksize(tfm));
-                       ret = -EINVAL;
-                       goto out;
-               }
-               
-               ops->cit_ivsize = crypto_tfm_alg_blocksize(tfm);
-               ops->cit_iv = kmalloc(ops->cit_ivsize, GFP_KERNEL);
-               if (ops->cit_iv == NULL)
-                       ret = -ENOMEM;
-       }
-
-out:   
-       return ret;
+       return 0;
 }
 
 void crypto_exit_cipher_ops(struct crypto_tfm *tfm)
 {
-       kfree(tfm->crt_cipher.cit_iv);
 }