+++ /dev/null
-crypto-API support for z990 Message Security Assist (MSA) instructions
-~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
-
-AUTHOR: Thomas Spatzier (tspat@de.ibm.com)
-
-
-1. Introduction crypto-API
-~~~~~~~~~~~~~~~~~~~~~~~~~~
-See Documentation/crypto/api-intro.txt for an introduction/description of the
-kernel crypto API.
-According to api-intro.txt support for z990 crypto instructions has been added
-in the algorithm api layer of the crypto API. Several files containing z990
-optimized implementations of crypto algorithms are placed in the
-arch/s390/crypto directory.
-
-
-2. Probing for availability of MSA
-~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
-It should be possible to use Kernels with the z990 crypto implementations both
-on machines with MSA available and on those without MSA (pre z990 or z990
-without MSA). Therefore a simple probing mechanism has been implemented:
-In the init function of each crypto module the availability of MSA and of the
-respective crypto algorithm in particular will be tested. If the algorithm is
-available the module will load and register its algorithm with the crypto API.
-
-If the respective crypto algorithm is not available, the init function will
-return -ENOSYS. In that case a fallback to the standard software implementation
-of the crypto algorithm must be taken ( -> the standard crypto modules are
-also built when compiling the kernel).
-
-
-3. Ensuring z990 crypto module preference
-~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
-If z990 crypto instructions are available the optimized modules should be
-preferred instead of standard modules.
-
-3.1. compiled-in modules
-~~~~~~~~~~~~~~~~~~~~~~~~
-For compiled-in modules it has to be ensured that the z990 modules are linked
-before the standard crypto modules. Then, on system startup the init functions
-of z990 crypto modules will be called first and query for availability of z990
-crypto instructions. If instruction is available, the z990 module will register
-its crypto algorithm implementation -> the load of the standard module will fail
-since the algorithm is already registered.
-If z990 crypto instruction is not available the load of the z990 module will
-fail -> the standard module will load and register its algorithm.
-
-3.2. dynamic modules
-~~~~~~~~~~~~~~~~~~~~
-A system administrator has to take care of giving preference to z990 crypto
-modules. If MSA is available appropriate lines have to be added to
-/etc/modprobe.conf.
-
-Example: z990 crypto instruction for SHA1 algorithm is available
-
- add the following line to /etc/modprobe.conf (assuming the
- z990 crypto modules for SHA1 is called sha1_z990):
-
- alias sha1 sha1_z990
-
- -> when the sha1 algorithm is requested through the crypto API
- (which has a module autoloader) the z990 module will be loaded.
-
-TBD: a userspace module probing mechanism
- something like 'probe sha1 sha1_z990 sha1' in modprobe.conf
- -> try module sha1_z990, if it fails to load standard module sha1
- the 'probe' statement is currently not supported in modprobe.conf
-
-
-4. Currently implemented z990 crypto algorithms
-~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
-The following crypto algorithms with z990 MSA support are currently implemented.
-The name of each algorithm under which it is registered in crypto API and the
-name of the respective module is given in square brackets.
-
-- SHA1 Digest Algorithm [sha1 -> sha1_z990]
-- DES Encrypt/Decrypt Algorithm (64bit key) [des -> des_z990]
-- Triple DES Encrypt/Decrypt Algorithm (128bit key) [des3_ede128 -> des_z990]
-- Triple DES Encrypt/Decrypt Algorithm (192bit key) [des3_ede -> des_z990]
-
-In order to load, for example, the sha1_z990 module when the sha1 algorithm is
-requested (see 3.2.) add 'alias sha1 sha1_z990' to /etc/modprobe.conf.
-
*/
#include <linux/init.h>
#include <linux/module.h>
-#include <linux/mm.h>
#include <linux/crypto.h>
-#include <asm/scatterlist.h>
-#include <asm/byteorder.h>
+
#include "crypt_s390.h"
#define SHA1_DIGEST_SIZE 20
#define SHA1_BLOCK_SIZE 64
-struct crypt_s390_sha1_ctx {
- u64 count;
+struct s390_sha1_ctx {
+ u64 count; /* message length */
u32 state[5];
- u32 buf_len;
- u8 buffer[2 * SHA1_BLOCK_SIZE];
+ u8 buf[2 * SHA1_BLOCK_SIZE];
};
static void sha1_init(struct crypto_tfm *tfm)
{
- struct crypt_s390_sha1_ctx *ctx = crypto_tfm_ctx(tfm);
-
- ctx->state[0] = 0x67452301;
- ctx->state[1] = 0xEFCDAB89;
- ctx->state[2] = 0x98BADCFE;
- ctx->state[3] = 0x10325476;
- ctx->state[4] = 0xC3D2E1F0;
-
- ctx->count = 0;
- ctx->buf_len = 0;
+ struct s390_sha1_ctx *sctx = crypto_tfm_ctx(tfm);
+
+ sctx->state[0] = 0x67452301;
+ sctx->state[1] = 0xEFCDAB89;
+ sctx->state[2] = 0x98BADCFE;
+ sctx->state[3] = 0x10325476;
+ sctx->state[4] = 0xC3D2E1F0;
+ sctx->count = 0;
}
static void sha1_update(struct crypto_tfm *tfm, const u8 *data,
unsigned int len)
{
- struct crypt_s390_sha1_ctx *sctx;
- long imd_len;
-
- sctx = crypto_tfm_ctx(tfm);
- sctx->count += len * 8; /* message bit length */
-
- /* anything in buffer yet? -> must be completed */
- if (sctx->buf_len && (sctx->buf_len + len) >= SHA1_BLOCK_SIZE) {
- /* complete full block and hash */
- memcpy(sctx->buffer + sctx->buf_len, data,
- SHA1_BLOCK_SIZE - sctx->buf_len);
- crypt_s390_kimd(KIMD_SHA_1, sctx->state, sctx->buffer,
- SHA1_BLOCK_SIZE);
- data += SHA1_BLOCK_SIZE - sctx->buf_len;
- len -= SHA1_BLOCK_SIZE - sctx->buf_len;
- sctx->buf_len = 0;
+ struct s390_sha1_ctx *sctx = crypto_tfm_ctx(tfm);
+ unsigned int index;
+ int ret;
+
+ /* how much is already in the buffer? */
+ index = sctx->count & 0x3f;
+
+ sctx->count += len;
+
+ if (index + len < SHA1_BLOCK_SIZE)
+ goto store;
+
+ /* process one stored block */
+ if (index) {
+ memcpy(sctx->buf + index, data, SHA1_BLOCK_SIZE - index);
+ ret = crypt_s390_kimd(KIMD_SHA_1, sctx->state, sctx->buf,
+ SHA1_BLOCK_SIZE);
+ BUG_ON(ret != SHA1_BLOCK_SIZE);
+ data += SHA1_BLOCK_SIZE - index;
+ len -= SHA1_BLOCK_SIZE - index;
}
- /* rest of data contains full blocks? */
- imd_len = len & ~0x3ful;
- if (imd_len) {
- crypt_s390_kimd(KIMD_SHA_1, sctx->state, data, imd_len);
- data += imd_len;
- len -= imd_len;
+ /* process as many blocks as possible */
+ if (len >= SHA1_BLOCK_SIZE) {
+ ret = crypt_s390_kimd(KIMD_SHA_1, sctx->state, data,
+ len & ~(SHA1_BLOCK_SIZE - 1));
+ BUG_ON(ret != (len & ~(SHA1_BLOCK_SIZE - 1)));
+ data += ret;
+ len -= ret;
}
- /* anything left? store in buffer */
- if (len) {
- memcpy(sctx->buffer + sctx->buf_len , data, len);
- sctx->buf_len += len;
- }
-}
+store:
+ /* anything left? */
+ if (len)
+ memcpy(sctx->buf + index , data, len);
+}
-static void pad_message(struct crypt_s390_sha1_ctx* sctx)
+/* Add padding and return the message digest. */
+static void sha1_final(struct crypto_tfm *tfm, u8 *out)
{
- int index;
+ struct s390_sha1_ctx *sctx = crypto_tfm_ctx(tfm);
+ u64 bits;
+ unsigned int index, end;
+ int ret;
+
+ /* must perform manual padding */
+ index = sctx->count & 0x3f;
+ end = (index < 56) ? SHA1_BLOCK_SIZE : (2 * SHA1_BLOCK_SIZE);
- index = sctx->buf_len;
- sctx->buf_len = (sctx->buf_len < 56) ?
- SHA1_BLOCK_SIZE:2 * SHA1_BLOCK_SIZE;
/* start pad with 1 */
- sctx->buffer[index] = 0x80;
+ sctx->buf[index] = 0x80;
+
/* pad with zeros */
index++;
- memset(sctx->buffer + index, 0x00, sctx->buf_len - index);
- /* append length */
- memcpy(sctx->buffer + sctx->buf_len - 8, &sctx->count,
- sizeof sctx->count);
-}
+ memset(sctx->buf + index, 0x00, end - index - 8);
-/* Add padding and return the message digest. */
-static void sha1_final(struct crypto_tfm *tfm, u8 *out)
-{
- struct crypt_s390_sha1_ctx *sctx = crypto_tfm_ctx(tfm);
+ /* append message length */
+ bits = sctx->count * 8;
+ memcpy(sctx->buf + end - 8, &bits, sizeof(bits));
+
+ ret = crypt_s390_kimd(KIMD_SHA_1, sctx->state, sctx->buf, end);
+ BUG_ON(ret != end);
- /* must perform manual padding */
- pad_message(sctx);
- crypt_s390_kimd(KIMD_SHA_1, sctx->state, sctx->buffer, sctx->buf_len);
/* copy digest to out */
memcpy(out, sctx->state, SHA1_DIGEST_SIZE);
+
/* wipe context */
memset(sctx, 0, sizeof *sctx);
}
.cra_priority = CRYPT_S390_PRIORITY,
.cra_flags = CRYPTO_ALG_TYPE_DIGEST,
.cra_blocksize = SHA1_BLOCK_SIZE,
- .cra_ctxsize = sizeof(struct crypt_s390_sha1_ctx),
+ .cra_ctxsize = sizeof(struct s390_sha1_ctx),
.cra_module = THIS_MODULE,
.cra_list = LIST_HEAD_INIT(alg.cra_list),
.cra_u = { .digest = {
#define SHA256_BLOCK_SIZE 64
struct s390_sha256_ctx {
- u64 count;
+ u64 count; /* message length */
u32 state[8];
u8 buf[2 * SHA256_BLOCK_SIZE];
};
int ret;
/* how much is already in the buffer? */
- index = sctx->count / 8 & 0x3f;
+ index = sctx->count & 0x3f;
- /* update message bit length */
- sctx->count += len * 8;
+ sctx->count += len;
if ((index + len) < SHA256_BLOCK_SIZE)
goto store;
memcpy(sctx->buf + index , data, len);
}
-static void pad_message(struct s390_sha256_ctx* sctx)
+/* Add padding and return the message digest */
+static void sha256_final(struct crypto_tfm *tfm, u8 *out)
{
- int index, end;
+ struct s390_sha256_ctx *sctx = crypto_tfm_ctx(tfm);
+ u64 bits;
+ unsigned int index, end;
+ int ret;
- index = sctx->count / 8 & 0x3f;
- end = index < 56 ? SHA256_BLOCK_SIZE : 2 * SHA256_BLOCK_SIZE;
+ /* must perform manual padding */
+ index = sctx->count & 0x3f;
+ end = (index < 56) ? SHA256_BLOCK_SIZE : (2 * SHA256_BLOCK_SIZE);
/* start pad with 1 */
sctx->buf[index] = 0x80;
memset(sctx->buf + index, 0x00, end - index - 8);
/* append message length */
- memcpy(sctx->buf + end - 8, &sctx->count, sizeof sctx->count);
-
- sctx->count = end * 8;
-}
-
-/* Add padding and return the message digest */
-static void sha256_final(struct crypto_tfm *tfm, u8 *out)
-{
- struct s390_sha256_ctx *sctx = crypto_tfm_ctx(tfm);
-
- /* must perform manual padding */
- pad_message(sctx);
+ bits = sctx->count * 8;
+ memcpy(sctx->buf + end - 8, &bits, sizeof(bits));
- crypt_s390_kimd(KIMD_SHA_256, sctx->state, sctx->buf,
- sctx->count / 8);
+ ret = crypt_s390_kimd(KIMD_SHA_256, sctx->state, sctx->buf, end);
+ BUG_ON(ret != end);
/* copy digest to out */
memcpy(out, sctx->state, SHA256_DIGEST_SIZE);
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