Commit graph

216 commits

Author SHA1 Message Date
Herbert Xu
d0b9007a27 [CRYPTO] pcbc: Use crypto_xor
This patch replaces the custom xor in CBC with the generic crypto_xor.

It changes the operations for in-place encryption slightly to avoid
calling crypto_xor with tmpbuf since it is not necessarily aligned.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2008-01-11 08:16:19 +11:00
Herbert Xu
50b6544e13 [CRYPTO] cbc: Require block size to be a power of 2
All common block ciphers have a block size that's a power of 2.  In fact,
all of our block ciphers obey this rule.

If we require this then CBC can be optimised to avoid an expensive divide
on in-place decryption.

I've also changed the saving of the first IV in the in-place decryption
case to the last IV because that lets us use walk->iv (which is already
aligned) for the xor operation where alignment is required.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2008-01-11 08:16:19 +11:00
Herbert Xu
3c7f076da5 [CRYPTO] cbc: Use crypto_xor
This patch replaces the custom xor in CBC with the generic crypto_xor.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2008-01-11 08:16:18 +11:00
Herbert Xu
7613636def [CRYPTO] api: Add crypto_inc and crypto_xor
With the addition of more stream ciphers we need to curb the proliferation
of ad-hoc xor functions.  This patch creates a generic pair of functions,
crypto_inc and crypto_xor which does big-endian increment and exclusive or,
respectively.

For optimum performance, they both use u32 operations so alignment must be
as that of u32 even though the arguments are of type u8 *.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2008-01-11 08:16:17 +11:00
Tan Swee Heng
2407d60872 [CRYPTO] salsa20: Salsa20 stream cipher
This patch implements the Salsa20 stream cipher using the blkcipher interface.

The core cipher code comes from Daniel Bernstein's submission to eSTREAM:
  http://www.ecrypt.eu.org/stream/svn/viewcvs.cgi/ecrypt/trunk/submissions/salsa20/full/ref/

The test vectors comes from:
  http://www.ecrypt.eu.org/stream/svn/viewcvs.cgi/ecrypt/trunk/submissions/salsa20/full/

It has been tested successfully with "modprobe tcrypt mode=34" on an
UML instance.

Signed-off-by: Tan Swee Heng <thesweeheng@gmail.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2008-01-11 08:16:15 +11:00
Herbert Xu
332f8840f7 [CRYPTO] ablkcipher: Add distinct ABLKCIPHER type
Up until now we have ablkcipher algorithms have been identified as
type BLKCIPHER with the ASYNC bit set.  This is suboptimal because
ablkcipher refers to two things.  On the one hand it refers to the
top-level ablkcipher interface with requests.  On the other hand it
refers to and algorithm type underneath.

As it is you cannot request a synchronous block cipher algorithm
with the ablkcipher interface on top.  This is a problem because
we want to be able to eventually phase out the blkcipher top-level
interface.

This patch fixes this by making ABLKCIPHER its own type, just as
we have distinct types for HASH and DIGEST.  The type it associated
with the algorithm implementation only.

Which top-level interface is used for synchronous block ciphers is
then determined by the mask that's used.  If it's a specific mask
then the old blkcipher interface is given, otherwise we go with the
new ablkcipher interface.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2008-01-11 08:16:15 +11:00
Herbert Xu
468577abe3 [CRYPTO] scatterwalk: Use generic scatterlist chaining
This patch converts the crypto scatterwalk code to use the generic
scatterlist chaining rather the version specific to crypto.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2008-01-11 08:16:14 +11:00
Jonathan Lynch
cd12fb906d [CRYPTO] sha256-generic: Extend sha256_generic.c to support SHA-224
Resubmitting this patch which extends sha256_generic.c to support SHA-224 as
described in FIPS 180-2 and RFC 3874. HMAC-SHA-224 as described in RFC4231
is then supported through the hmac interface.

Patch includes test vectors for SHA-224 and HMAC-SHA-224.

SHA-224 chould be chosen as a hash algorithm when 112 bits of security
strength is required.

Patch generated against the 2.6.24-rc1 kernel and tested against
2.6.24-rc1-git14 which includes fix for scatter gather implementation for HMAC.

Signed-off-by: Jonathan Lynch <jonathan.lynch@intel.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2008-01-11 08:16:12 +11:00
Sebastian Siewior
5157dea813 [CRYPTO] aes-i586: Remove setkey
The setkey() function can be shared with the generic algorithm.

Signed-off-by: Sebastian Siewior <sebastian@breakpoint.cc>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2008-01-11 08:16:10 +11:00
Sebastian Siewior
b345cee90a [CRYPTO] ctr: Remove default M
NO other block mode is M by default.

Signed-off-by: Sebastian Siewior <sebastian@breakpoint.cc>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2008-01-11 08:16:10 +11:00
Sebastian Siewior
81190b3215 [CRYPTO] aes-x86-64: Remove setkey
The setkey() function can be shared with the generic algorithm.

Signed-off-by: Sebastian Siewior <sebastian@breakpoint.cc>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2008-01-11 08:16:10 +11:00
Sebastian Siewior
96e82e4551 [CRYPTO] aes-generic: Make key generation exportable
This patch exports four tables and the set_key() routine. This ressources
can be shared by other AES implementations (aes-x86_64 for instance).
The decryption key has been turned around (deckey[0] is the first piece
of the key instead of deckey[keylen+20]). The encrypt/decrypt functions
are looking now identical (except they are using different tables and
key).

Signed-off-by: Sebastian Siewior <sebastian@breakpoint.cc>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2008-01-11 08:16:09 +11:00
Sebastian Siewior
be5fb27012 [CRYPTO] aes-generic: Coding style cleanup
Signed-off-by: Sebastian Siewior <sebastian@breakpoint.cc>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2008-01-11 08:16:09 +11:00
Joy Latten
41fdab3dd3 [CRYPTO] ctr: Add countersize
This patch adds countersize to CTR mode.
The template is now ctr(algo,noncesize,ivsize,countersize).

For example, ctr(aes,4,8,4) indicates the counterblock
will be composed of a salt/nonce that is 4 bytes, an iv
that is 8 bytes and the counter is 4 bytes.

When noncesize + ivsize < blocksize, CTR initializes the
last block - ivsize - noncesize portion of the block to
zero.  Otherwise the counter block is composed of the IV
(and nonce if necessary).

If noncesize + ivsize == blocksize, then this indicates that
user is passing in entire counterblock. Thus countersize
indicates the amount of bytes in counterblock to use as
the counter for incrementing. CTR will increment counter
portion by 1, and begin encryption with that value.

Note that CTR assumes the counter portion of the block that
will be incremented is stored in big endian.

Signed-off-by: Joy Latten <latten@austin.ibm.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2008-01-11 08:16:08 +11:00
Denys Vlasenko
d3e7480572 [CRYPTO] camellia: De-unrolling
Move huge unrolled pieces of code (3 screenfuls) at the end of
128/256 key setup routines into common camellia_setup_tail(),
convert it to loop there.
Loop is still unrolled six times, so performance hit is very small,
code size win is big.

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
Acked-by: Noriaki TAKAMIYA <takamiya@po.ntts.co.jp>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2008-01-11 08:16:08 +11:00
Denys Vlasenko
1ce73e8d6d [CRYPTO] camellia: Code cleanup
Optimize GETU32 to use 4-byte memcpy (modern gcc will convert
such memcpy to single move instruction on i386).
Original GETU32 did four byte fetches, and shifted/XORed those.

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
Acked-by: Noriaki TAKAMIYA <takamiya@po.ntts.co.jp>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2008-01-11 08:16:07 +11:00
Denys Vlasenko
3a5e5f8108 [CRYPTO] camellia: Code cleanup
Rename some macros to shorter names: CAMELLIA_RR8 -> ROR8,
making it easier to understand that it is just a right rotation,
nothing camellia-specific in it.
CAMELLIA_SUBKEY_L() -> SUBKEY_L() - just shorter.

Move be32 <-> cpu conversions out of en/decrypt128/256 and into
camellia_en/decrypt - no reason to have that code duplicated twice.

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
Acked-by: Noriaki TAKAMIYA <takamiya@po.ntts.co.jp>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2008-01-11 08:16:07 +11:00
Denys Vlasenko
1721a81256 [CRYPTO] camellia: Code cleanup
Move code blocks around so that related pieces are closer together:
e.g. CAMELLIA_ROUNDSM macro does not need to be separated
from the rest of the code by huge array of constants.

Remove unused macros (COPY4WORD, SWAP4WORD, XOR4WORD[2])

Drop SUBL(), SUBR() macros which only obscure things.
Same for CAMELLIA_SP1110() macro and KEY_TABLE_TYPE typedef.

Remove useless comments:
/* encryption */ -- well it's obvious enough already!
void camellia_encrypt128(...)

Combine swap with copying at the beginning/end of encrypt/decrypt.

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
Acked-by: Noriaki TAKAMIYA <takamiya@po.ntts.co.jp>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2008-01-11 08:16:06 +11:00
Denys Vlasenko
e2b21b5002 [CRYPTO] twofish: Do not unroll big stuff in twofish key setup
Currently twofish cipher key setup code
has unrolled loops - approximately 70-100
instructions are repeated 40 times.

As a result, twofish module is the biggest module
in crypto/*.

Unrolling produces x2.5 more code (+18k on i386), and speeds up key
setup by 7%:

	unrolled: twofish_setkey/sec: 41128
	    loop: twofish_setkey/sec: 38148
	CALC_K256: ~100 insns each
	CALC_K192: ~90 insns
	   CALC_K: ~70 insns

Attached patch removes this unrolling.

$ size */twofish_common.o
   text    data     bss     dec     hex filename
  37920       0       0   37920    9420 crypto.org/twofish_common.o
  13209       0       0   13209    3399 crypto/twofish_common.o

Run tested (modprobe tcrypt reports ok). Please apply.

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2008-01-11 08:16:06 +11:00
Sebastian Siewior
89e1265431 [CRYPTO] aes: Move common defines into a header file
This three defines are used in all AES related hardware.

Signed-off-by: Sebastian Siewior <sebastian@breakpoint.cc>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2008-01-11 08:16:04 +11:00
Evgeniy Polyakov
c3041f9c93 [CRYPTO] hifn_795x: Detect weak keys
HIFN driver update to use DES weak key checks (exported in this patch).

Signed-off-by: Evgeniy Polyakov <johnpol@2ka.mipt.ru>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2008-01-11 08:16:03 +11:00
Evgeniy Polyakov
16d004a2ed [CRYPTO] des: Create header file for common macros
This patch creates include/crypto/des.h for common macros shared between
DES implementations.

Signed-off-by: Evgeniy Polyakov <johnpol@2ka.mipt.ru>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2008-01-11 08:16:02 +11:00
Joy Latten
23e353c8a6 [CRYPTO] ctr: Add CTR (Counter) block cipher mode
This patch implements CTR mode for IPsec.
It is based off of RFC 3686.

Please note:
1. CTR turns a block cipher into a stream cipher.
Encryption is done in blocks, however the last block
may be a partial block.

A "counter block" is encrypted, creating a keystream
that is xor'ed with the plaintext. The counter portion
of the counter block is incremented after each block
of plaintext is encrypted.
Decryption is performed in same manner.

2. The CTR counterblock is composed of,
        nonce + IV + counter

The size of the counterblock is equivalent to the
blocksize of the cipher.
        sizeof(nonce) + sizeof(IV) + sizeof(counter) = blocksize

The CTR template requires the name of the cipher
algorithm, the sizeof the nonce, and the sizeof the iv.
        ctr(cipher,sizeof_nonce,sizeof_iv)

So for example,
        ctr(aes,4,8)
specifies the counterblock will be composed of 4 bytes
from a nonce, 8 bytes from the iv, and 4 bytes for counter
since aes has a blocksize of 16 bytes.

3. The counter portion of the counter block is stored
in big endian for conformance to rfc 3686.

Signed-off-by: Joy Latten <latten@austin.ibm.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2008-01-11 08:16:01 +11:00
Herbert Xu
38cb2419f5 [CRYPTO] api: Fix potential race in crypto_remove_spawn
As it is crypto_remove_spawn may try to unregister an instance which is
yet to be registered.  This patch fixes this by checking whether the
instance has been registered before attempting to remove it.

It also removes a bogus cra_destroy check in crypto_register_instance as
1) it's outside the mutex;
2) we have a check in __crypto_register_alg already.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2007-11-23 19:32:09 +08:00
Herbert Xu
f347c4facf [CRYPTO] authenc: Move initialisations up to shut up gcc
It seems that newer versions of gcc have regressed in their abilities to
analyse initialisations.  This patch moves the initialisations up to avoid
the warnings.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2007-11-23 19:32:09 +08:00
Adrian Bunk
87ae9afdca cleanup asm/scatterlist.h includes
Not architecture specific code should not #include <asm/scatterlist.h>.

This patch therefore either replaces them with
#include <linux/scatterlist.h> or simply removes them if they were
unused.

Signed-off-by: Adrian Bunk <bunk@kernel.org>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2007-11-02 08:47:06 +01:00
Herbert Xu
a5a613a429 [CRYPTO] tcrypt: Move sg_init_table out of timing loops
This patch moves the sg_init_table out of the timing loops for hash
algorithms so that it doesn't impact on the speed test results.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
2007-10-27 00:51:21 -07:00
David S. Miller
b733588559 [CRYPTO]: Initialize TCRYPT on-stack scatterlist objects correctly.
Use sg_init_one() and sg_init_table() as needed.

Signed-off-by: David S. Miller <davem@davemloft.net>
2007-10-26 00:38:10 -07:00
David S. Miller
a6767721a5 [CRYPTO]: HMAC needs some more scatterlist fixups.
hmac_setkey(), hmac_init(), and hmac_final() have
a singular on-stack scatterlist.  Initialit is
using sg_init_one() instead of using sg_set_buf().

Signed-off-by: David S. Miller <davem@davemloft.net>
2007-10-26 00:37:12 -07:00
Vlad Yasevich
41fb285430 [CRYPTO]: Fix hmac_digest from the SG breakage.
Crypto now uses SG helper functions.  Fix hmac_digest to use those
functions correctly and fix the oops associated with it.

Signed-off-by: Vlad Yasevich <vladislav.yasevich@hp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2007-10-25 18:46:26 -07:00
Jens Axboe
642f149031 SG: Change sg_set_page() to take length and offset argument
Most drivers need to set length and offset as well, so may as well fold
those three lines into one.

Add sg_assign_page() for those two locations that only needed to set
the page, where the offset/length is set outside of the function context.

Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2007-10-24 11:20:47 +02:00
Jens Axboe
78c2f0b8c2 [SG] Update crypto/ to sg helpers
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2007-10-22 19:40:16 +02:00
John Anthony Kazos Jr
991d17403c crypto: convert "crypto" subdirectory to UTF-8
Convert the subdirectory "crypto" to UTF-8. The files changed are
<crypto/fcrypt.c> and <crypto/api.c>.

Signed-off-by: John Anthony Kazos Jr. <jakj@j-a-k-j.com>
Signed-off-by: Adrian Bunk <bunk@kernel.org>
2007-10-19 23:06:17 +02:00
Jens Axboe
ab83407e9e crypto: don't pollute the global namespace with sg_next()
It's a subsystem function, prefix it as such.

Acked-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2007-10-16 11:07:09 +02:00
Jan Glauber
5265eeb2b0 [CRYPTO] sha: Add header file for SHA definitions
There are currently several SHA implementations that all define their own
initialization vectors and size values. Since this values are idential
move them to a header file under include/crypto.

Signed-off-by: Jan Glauber <jang@de.ibm.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2007-10-10 16:55:50 -07:00
Sebastian Siewior
ad5d27899f [CRYPTO] sha: Load the SHA[1|256] module by an alias
Loading the crypto algorithm by the alias instead of by module directly
has the advantage that all possible implementations of this algorithm
are loaded automatically and the crypto API can choose the best one
depending on its priority.

Additionally it ensures that the generic implementation as well as the
HW driver (if available) is loaded in case the HW driver needs the
generic version as fallback in corner cases.

Also remove the probe for sha1 in padlock's init code.

Quote from Herbert:
  The probe is actually pointless since we can always probe when
  the algorithm is actually used which does not lead to dead-locks
  like this.

Signed-off-by: Sebastian Siewior <sebastian@breakpoint.cc>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2007-10-10 16:55:50 -07:00
Sebastian Siewior
f8246af005 [CRYPTO] aes: Rename aes to aes-generic
Loading the crypto algorithm by the alias instead of by module directly
has the advantage that all possible implementations of this algorithm
are loaded automatically and the crypto API can choose the best one
depending on its priority.

Additionally it ensures that the generic implementation as well as the
HW driver (if available) is loaded in case the HW driver needs the
generic version as fallback in corner cases.

Signed-off-by: Sebastian Siewior <sebastian@breakpoint.cc>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2007-10-10 16:55:49 -07:00
Sebastian Siewior
c5a511f1cd [CRYPTO] des: Rename des to des-generic
Loading the crypto algorithm by the alias instead of by module directly
has the advantage that all possible implementations of this algorithm
are loaded automatically and the crypto API can choose the best one
depending on its priority.

Signed-off-by: Sebastian Siewior <sebastian@breakpoint.cc>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2007-10-10 16:55:49 -07:00
Herbert Xu
7607bd8ff0 [CRYPTO] blkcipher: Added blkcipher_walk_virt_block
This patch adds the helper blkcipher_walk_virt_block which is similar to
blkcipher_walk_virt but uses a supplied block size instead of the block
size of the block cipher.  This is useful for CTR where the block size is
1 but we still want to walk by the block size of the underlying cipher.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2007-10-10 16:55:48 -07:00
Herbert Xu
2614de1b9a [CRYPTO] blkcipher: Increase kmalloc amount to aligned block size
Now that the block size is no longer a multiple of the alignment, we need to
increase the kmalloc amount in blkcipher_next_slow to use the aligned block
size.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2007-10-10 16:55:48 -07:00
Herbert Xu
d8058480b3 [CRYPTO] api: Explain the comparison on larval cra_name
This patch adds a comment to explain why we compare the cra_driver_name of
the algorithm being registered against the cra_name of a larval as opposed
to the cra_driver_name of the larval.

In fact larvals have only one name, cra_name which is the name that was
requested by the user.  The test here is simply trying to find out whether
the algorithm being registered can or can not satisfy the larval.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2007-10-10 16:55:47 -07:00
Herbert Xu
70613783fc [CRYPTO] blkcipher: Remove alignment restriction on block size
Previously we assumed for convenience that the block size is a multiple of
the algorithm's required alignment.  With the pending addition of CTR this
will no longer be the case as the block size will be 1 due to it being a
stream cipher.  However, the alignment requirement will be that of the
underlying implementation which will most likely be greater than 1.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2007-10-10 16:55:46 -07:00
Herbert Xu
e4c5c6c9b0 [CRYPTO] authenc: Kill spaces in algorithm names
We do not allow spaces in algorithm names or parameters.  Thanks to Joy Latten
for pointing this out.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2007-10-10 16:55:46 -07:00
Herbert Xu
720a650f8a [CRYPTO] cryptomgr: Fix parsing of recursive algorithms
As Joy Latten points out, inner algorithm parameters will miss the closing
bracket which will also cause the outer algorithm to terminate prematurely.

This patch fixes that also kills the WARN_ON if the number of parameters
exceed the maximum as that is a user error.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2007-10-10 16:55:45 -07:00
Rik Snel
f19f5111c9 [CRYPTO] xts: XTS blockcipher mode implementation without partial blocks
XTS currently considered to be the successor of the LRW mode by the IEEE1619
workgroup. LRW was discarded, because it was not secure if the encyption key
itself is encrypted with LRW.

XTS does not have this problem. The implementation is pretty straightforward,
a new function was added to gf128mul to handle GF(128) elements in ble format.
Four testvectors from the specification
	http://grouper.ieee.org/groups/1619/email/pdf00086.pdf
were added, and they verify on my system.

Signed-off-by: Rik Snel <rsnel@cube.dyndns.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2007-10-10 16:55:45 -07:00
Ingo Oeser
5aaff0c8f7 [CRYPTO] blkcipher: Use max() in blkcipher_get_spot() to state the intention
Use max in blkcipher_get_spot() instead of open coding it.

Signed-off-by: Ingo Oeser <ioe-lkml@rameria.de>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2007-10-10 16:55:44 -07:00
Herbert Xu
70dec235d8 [CRYPTO] api: Kill crypto_km_types
When scatterwalk is built as a module digest.c was broken because it
requires the crypto_km_types structure which is in scatterwalk.  This
patch removes the crypto_km_types structure by encoding the logic into
crypto_kmap_type directly.

In fact, this even saves a few bytes of code (not to mention the data
structure itself) on i386 which is about the only place where it's
needed.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2007-10-10 16:55:44 -07:00
Herbert Xu
3c09f17c3d [CRYPTO] aead: Add authenc
This patch adds the authenc algorithm which constructs an AEAD algorithm
from an asynchronous block cipher and a hash.  The construction is done
by concatenating the encrypted result from the cipher with the output
from the hash, as is used by the IPsec ESP protocol.

The authenc algorithm exists as a template with four parameters:

	authenc(auth, authsize, enc, enckeylen).

The authentication algorithm, the authentication size (i.e., truncating
the output of the authentication algorithm), the encryption algorithm,
and the encryption key length.  Both the size field and the key length
field are in bytes.  For example, AES-128 with SHA1-HMAC would be
represented by

	authenc(hmac(sha1), 12, cbc(aes), 16)

The key for the authenc algorithm is the concatenation of the keys for
the authentication algorithm with the encryption algorithm.  For the
above example, if a key of length 36 bytes is given, then hmac(sha1)
would receive the first 20 bytes while the last 16 would be given to
cbc(aes).

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2007-10-10 16:55:43 -07:00
Herbert Xu
5fa0fea274 [CRYPTO] scatterwalk: Add scatterwalk_map_and_copy
This patch adds the function scatterwalk_map_and_copy which reads or
writes a chunk of data from a scatterlist at a given offset.  It will
be used by authenc which would read/write the authentication data at
the end of the cipher/plain text.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2007-10-10 16:55:42 -07:00
Herbert Xu
e962a653f3 [CRYPTO] api: Move scatterwalk into algapi
The scatterwalk code is only used by algorithms that can be built as
a module.  Therefore we can move it into algapi.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2007-10-10 16:55:41 -07:00