Merge branch 'modsplit-Oct31_2011' of git://git.kernel.org/pub/scm/linux/kernel/git...
[linux-2.6.git] / crypto / cipher.c
index 8da6443..39541e0 100644 (file)
  *
  * 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
- * Software Foundation; either version 2 of the License, or (at your option) 
+ * Software Foundation; either version 2 of the License, or (at your option)
  * 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"
-
-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 unsigned int crypt_slow(const struct cipher_desc *desc,
-                              struct scatter_walk *in,
-                              struct scatter_walk *out, unsigned int bsize)
-{
-       unsigned long alignmask = crypto_tfm_alg_alignmask(desc->tfm);
-       u8 buffer[bsize * 2 + alignmask];
-       u8 *src = (u8 *)ALIGN((unsigned long)buffer, alignmask + 1);
-       u8 *dst = src + bsize;
-       unsigned int n;
-
-       n = scatterwalk_copychunks(src, in, bsize, 0);
-       scatterwalk_advance(in, n);
-
-       desc->prfn(desc, dst, src, bsize);
-
-       n = scatterwalk_copychunks(dst, out, bsize, 1);
-       scatterwalk_advance(out, n);
-
-       return bsize;
-}
-
-static inline unsigned int crypt_fast(const struct cipher_desc *desc,
-                                     struct scatter_walk *in,
-                                     struct scatter_walk *out,
-                                     unsigned int nbytes, u8 *tmp)
-{
-       u8 *src, *dst;
-
-       src = in->data;
-       dst = scatterwalk_samebuf(in, out) ? src : out->data;
-
-       if (tmp) {
-               memcpy(tmp, in->data, nbytes);
-               src = tmp;
-               dst = tmp;
-       }
 
-       nbytes = desc->prfn(desc, dst, src, nbytes);
-
-       if (tmp)
-               memcpy(out->data, tmp, nbytes);
-
-       scatterwalk_advance(in, nbytes);
-       scatterwalk_advance(out, nbytes);
-
-       return nbytes;
-}
-
-/* 
- * 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 page.
- */
-static int crypt(const struct cipher_desc *desc,
-                struct scatterlist *dst,
-                struct scatterlist *src,
-                unsigned int nbytes)
+static int setkey_unaligned(struct crypto_tfm *tfm, const u8 *key,
+                           unsigned int keylen)
 {
-       struct scatter_walk walk_in, walk_out;
-       struct crypto_tfm *tfm = desc->tfm;
-       const unsigned int bsize = crypto_tfm_alg_blocksize(tfm);
-       unsigned int alignmask = crypto_tfm_alg_alignmask(tfm);
-       unsigned long buffer = 0;
-
-       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(;;) {
-               unsigned int n = nbytes;
-               u8 *tmp = NULL;
-
-               if (!scatterwalk_aligned(&walk_in, alignmask) ||
-                   !scatterwalk_aligned(&walk_out, alignmask)) {
-                       if (!buffer) {
-                               buffer = __get_free_page(GFP_ATOMIC);
-                               if (!buffer)
-                                       n = 0;
-                       }
-                       tmp = (u8 *)buffer;
-               }
-
-               scatterwalk_map(&walk_in, 0);
-               scatterwalk_map(&walk_out, 1);
-
-               n = scatterwalk_clamp(&walk_in, n);
-               n = scatterwalk_clamp(&walk_out, n);
-
-               if (likely(n >= bsize))
-                       n = crypt_fast(desc, &walk_in, &walk_out, n, tmp);
-               else
-                       n = crypt_slow(desc, &walk_in, &walk_out, bsize);
-
-               nbytes -= n;
-
-               scatterwalk_done(&walk_in, 0, nbytes);
-               scatterwalk_done(&walk_out, 1, nbytes);
-
-               if (!nbytes)
-                       break;
-
-               crypto_yield(tfm);
-       }
-
-       if (buffer)
-               free_page(buffer);
-
-       return 0;
-}
-
-static int crypt_iv_unaligned(struct cipher_desc *desc,
-                             struct scatterlist *dst,
-                             struct scatterlist *src,
-                             unsigned int nbytes)
-{
-       struct crypto_tfm *tfm = desc->tfm;
+       struct cipher_alg *cia = &tfm->__crt_alg->cra_cipher;
        unsigned long alignmask = crypto_tfm_alg_alignmask(tfm);
-       u8 *iv = desc->info;
-
-       if (unlikely(((unsigned long)iv & alignmask))) {
-               unsigned int ivsize = tfm->crt_cipher.cit_ivsize;
-               u8 buffer[ivsize + alignmask];
-               u8 *tmp = (u8 *)ALIGN((unsigned long)buffer, alignmask + 1);
-               int err;
-
-               desc->info = memcpy(tmp, iv, ivsize);
-               err = crypt(desc, dst, src, nbytes);
-               memcpy(iv, tmp, ivsize);
-
-               return err;
-       }
-
-       return crypt(desc, dst, src, nbytes);
-}
-
-static unsigned int cbc_process_encrypt(const struct cipher_desc *desc,
-                                       u8 *dst, const u8 *src,
-                                       unsigned int nbytes)
-{
-       struct crypto_tfm *tfm = desc->tfm;
-       void (*xor)(u8 *, const u8 *) = tfm->crt_u.cipher.cit_xor_block;
-       int bsize = crypto_tfm_alg_blocksize(tfm);
-
-       void (*fn)(void *, u8 *, const u8 *) = desc->crfn;
-       u8 *iv = desc->info;
-       unsigned int done = 0;
-
-       do {
-               xor(iv, src);
-               fn(crypto_tfm_ctx(tfm), dst, iv);
-               memcpy(iv, dst, bsize);
-
-               src += bsize;
-               dst += bsize;
-       } while ((done += bsize) < nbytes);
-
-       return done;
-}
-
-static unsigned int cbc_process_decrypt(const struct cipher_desc *desc,
-                                       u8 *dst, const u8 *src,
-                                       unsigned int nbytes)
-{
-       struct crypto_tfm *tfm = desc->tfm;
-       void (*xor)(u8 *, const u8 *) = tfm->crt_u.cipher.cit_xor_block;
-       int bsize = crypto_tfm_alg_blocksize(tfm);
-
-       u8 stack[src == dst ? bsize : 0];
-       u8 *buf = stack;
-       u8 **dst_p = src == dst ? &buf : &dst;
-
-       void (*fn)(void *, u8 *, const u8 *) = desc->crfn;
-       u8 *iv = desc->info;
-       unsigned int done = 0;
-
-       do {
-               u8 *tmp_dst = *dst_p;
-
-               fn(crypto_tfm_ctx(tfm), tmp_dst, src);
-               xor(tmp_dst, iv);
-               memcpy(iv, src, bsize);
-               if (tmp_dst != dst)
-                       memcpy(dst, tmp_dst, bsize);
-
-               src += bsize;
-               dst += bsize;
-       } while ((done += bsize) < nbytes);
-
-       return done;
-}
-
-static unsigned int ecb_process(const struct cipher_desc *desc, u8 *dst,
-                               const u8 *src, unsigned int nbytes)
-{
-       struct crypto_tfm *tfm = desc->tfm;
-       int bsize = crypto_tfm_alg_blocksize(tfm);
-       void (*fn)(void *, u8 *, const u8 *) = desc->crfn;
-       unsigned int done = 0;
-
-       do {
-               fn(crypto_tfm_ctx(tfm), dst, src);
-
-               src += bsize;
-               dst += bsize;
-       } while ((done += bsize) < nbytes);
+       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;
 
-       return done;
 }
 
 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)
-{
-       struct cipher_desc desc;
-       struct cipher_alg *cipher = &tfm->__crt_alg->cra_cipher;
-
-       desc.tfm = tfm;
-       desc.crfn = cipher->cia_encrypt;
-       desc.prfn = cipher->cia_encrypt_ecb ?: ecb_process;
-
-       return crypt(&desc, dst, src, nbytes);
-}
-
-static int ecb_decrypt(struct crypto_tfm *tfm,
-                       struct scatterlist *dst,
-                       struct scatterlist *src,
-                      unsigned int nbytes)
-{
-       struct cipher_desc desc;
-       struct cipher_alg *cipher = &tfm->__crt_alg->cra_cipher;
-
-       desc.tfm = tfm;
-       desc.crfn = cipher->cia_decrypt;
-       desc.prfn = cipher->cia_decrypt_ecb ?: ecb_process;
-
-       return crypt(&desc, dst, src, nbytes);
-}
-
-static int cbc_encrypt(struct crypto_tfm *tfm,
-                       struct scatterlist *dst,
-                       struct scatterlist *src,
-                      unsigned int nbytes)
-{
-       struct cipher_desc desc;
-       struct cipher_alg *cipher = &tfm->__crt_alg->cra_cipher;
+       }
 
-       desc.tfm = tfm;
-       desc.crfn = cipher->cia_encrypt;
-       desc.prfn = cipher->cia_encrypt_cbc ?: cbc_process_encrypt;
-       desc.info = tfm->crt_cipher.cit_iv;
+       if ((unsigned long)key & alignmask)
+               return setkey_unaligned(tfm, key, keylen);
 
-       return crypt(&desc, dst, src, nbytes);
+       return cia->cia_setkey(tfm, key, keylen);
 }
 
-static int cbc_encrypt_iv(struct crypto_tfm *tfm,
-                          struct scatterlist *dst,
-                          struct scatterlist *src,
-                          unsigned int nbytes, u8 *iv)
+static void cipher_crypt_unaligned(void (*fn)(struct crypto_tfm *, u8 *,
+                                             const u8 *),
+                                  struct crypto_tfm *tfm,
+                                  u8 *dst, const u8 *src)
 {
-       struct cipher_desc desc;
-       struct cipher_alg *cipher = &tfm->__crt_alg->cra_cipher;
-
-       desc.tfm = tfm;
-       desc.crfn = cipher->cia_encrypt;
-       desc.prfn = cipher->cia_encrypt_cbc ?: cbc_process_encrypt;
-       desc.info = 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);
 
-       return crypt_iv_unaligned(&desc, dst, src, nbytes);
+       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)
 {
-       struct cipher_desc desc;
+       unsigned long alignmask = crypto_tfm_alg_alignmask(tfm);
        struct cipher_alg *cipher = &tfm->__crt_alg->cra_cipher;
 
-       desc.tfm = tfm;
-       desc.crfn = cipher->cia_decrypt;
-       desc.prfn = cipher->cia_decrypt_cbc ?: cbc_process_decrypt;
-       desc.info = tfm->crt_cipher.cit_iv;
+       if (unlikely(((unsigned long)dst | (unsigned long)src) & alignmask)) {
+               cipher_crypt_unaligned(cipher->cia_encrypt, tfm, dst, src);
+               return;
+       }
 
-       return crypt(&desc, dst, src, nbytes);
+       cipher->cia_encrypt(tfm, dst, src);
 }
 
-static int cbc_decrypt_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)
 {
-       struct cipher_desc desc;
+       unsigned long alignmask = crypto_tfm_alg_alignmask(tfm);
        struct cipher_alg *cipher = &tfm->__crt_alg->cra_cipher;
 
-       desc.tfm = tfm;
-       desc.crfn = cipher->cia_decrypt;
-       desc.prfn = cipher->cia_decrypt_cbc ?: cbc_process_decrypt;
-       desc.info = iv;
-
-       return crypt_iv_unaligned(&desc, dst, src, nbytes);
-}
-
-static int nocrypt(struct crypto_tfm *tfm,
-                   struct scatterlist *dst,
-                   struct scatterlist *src,
-                  unsigned int nbytes)
-{
-       return -ENOSYS;
-}
-
-static int nocrypt_iv(struct crypto_tfm *tfm,
-                      struct scatterlist *dst,
-                      struct scatterlist *src,
-                      unsigned int nbytes, u8 *iv)
-{
-       return -ENOSYS;
-}
+       if (unlikely(((unsigned long)dst | (unsigned long)src) & alignmask)) {
+               cipher_crypt_unaligned(cipher->cia_decrypt, tfm, dst, src);
+               return;
+       }
 
-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;
+       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) {
-               unsigned long align;
-               unsigned long addr;
-               
-               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);
-               align = crypto_tfm_alg_alignmask(tfm) + 1;
-               addr = (unsigned long)crypto_tfm_ctx(tfm);
-               addr = ALIGN(addr, align);
-               addr += ALIGN(tfm->__crt_alg->cra_ctxsize, align);
-               ops->cit_iv = (void *)addr;
-       }
-
-out:   
-       return ret;
+       return 0;
 }
 
 void crypto_exit_cipher_ops(struct crypto_tfm *tfm)