[PATCH] s390: sha256 support

[pandora-kernel.git] / arch / s390 / crypto / sha256_s390.c

diff --git a/arch/s390/crypto/sha256_s390.c b/arch/s390/crypto/sha256_s390.c
new file mode 100644 (file)
index 0000000..b75bdbd
--- /dev/null
+++ b/arch/s390/crypto/sha256_s390.c
@@ -0,0 +1,151 @@
+/*
+ * Cryptographic API.
+ *
+ * s390 implementation of the SHA256 Secure Hash Algorithm.
+ *
+ * s390 Version:
+ *   Copyright (C) 2005 IBM Deutschland GmbH, IBM Corporation
+ *   Author(s): Jan Glauber (jang@de.ibm.com)
+ *
+ * Derived from "crypto/sha256.c"
+ * and "arch/s390/crypto/sha1_s390.c"
+ *
+ * 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)
+ * any later version.
+ *
+ */
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/crypto.h>
+
+#include "crypt_s390.h"
+
+#define SHA256_DIGEST_SIZE     32
+#define SHA256_BLOCK_SIZE      64
+
+struct s390_sha256_ctx {
+       u64 count;
+       u32 state[8];
+       u8 buf[2 * SHA256_BLOCK_SIZE];
+};
+
+static void sha256_init(void *ctx)
+{
+       struct s390_sha256_ctx *sctx = ctx;
+
+       sctx->state[0] = 0x6a09e667;
+       sctx->state[1] = 0xbb67ae85;
+       sctx->state[2] = 0x3c6ef372;
+       sctx->state[3] = 0xa54ff53a;
+       sctx->state[4] = 0x510e527f;
+       sctx->state[5] = 0x9b05688c;
+       sctx->state[6] = 0x1f83d9ab;
+       sctx->state[7] = 0x5be0cd19;
+       sctx->count = 0;
+       memset(sctx->buf, 0, sizeof(sctx->buf));
+}
+
+static void sha256_update(void *ctx, const u8 *data, unsigned int len)
+{
+       struct s390_sha256_ctx *sctx = ctx;
+       unsigned int index;
+
+       /* how much is already in the buffer? */
+       index = sctx->count / 8 & 0x3f;
+
+       /* update message bit length */
+       sctx->count += len * 8;
+
+       /* process one block */
+       if ((index + len) >= SHA256_BLOCK_SIZE) {
+               memcpy(sctx->buf + index, data, SHA256_BLOCK_SIZE - index);
+               crypt_s390_kimd(KIMD_SHA_256, sctx->state, sctx->buf,
+                               SHA256_BLOCK_SIZE);
+               data += SHA256_BLOCK_SIZE - index;
+               len -= SHA256_BLOCK_SIZE - index;
+       }
+
+       /* anything left? */
+       if (len)
+               memcpy(sctx->buf + index , data, len);
+}
+
+static void pad_message(struct s390_sha256_ctx* sctx)
+{
+       int index, end;
+
+       index = sctx->count / 8 & 0x3f;
+       end = index < 56 ? SHA256_BLOCK_SIZE : 2 * SHA256_BLOCK_SIZE;
+
+       /* start pad with 1 */
+       sctx->buf[index] = 0x80;
+
+       /* pad with zeros */
+       index++;
+       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(void* ctx, u8 *out)
+{
+       struct s390_sha256_ctx *sctx = ctx;
+
+       /* must perform manual padding */
+       pad_message(sctx);
+
+       crypt_s390_kimd(KIMD_SHA_256, sctx->state, sctx->buf,
+                       sctx->count / 8);
+
+       /* copy digest to out */
+       memcpy(out, sctx->state, SHA256_DIGEST_SIZE);
+
+       /* wipe context */
+       memset(sctx, 0, sizeof *sctx);
+}
+
+static struct crypto_alg alg = {
+       .cra_name       =       "sha256",
+       .cra_flags      =       CRYPTO_ALG_TYPE_DIGEST,
+       .cra_blocksize  =       SHA256_BLOCK_SIZE,
+       .cra_ctxsize    =       sizeof(struct s390_sha256_ctx),
+       .cra_module     =       THIS_MODULE,
+       .cra_list       =       LIST_HEAD_INIT(alg.cra_list),
+       .cra_u          =       { .digest = {
+       .dia_digestsize =       SHA256_DIGEST_SIZE,
+       .dia_init       =       sha256_init,
+       .dia_update     =       sha256_update,
+       .dia_final      =       sha256_final } }
+};
+
+static int init(void)
+{
+       int ret;
+
+       if (!crypt_s390_func_available(KIMD_SHA_256))
+               return -ENOSYS;
+
+       ret = crypto_register_alg(&alg);
+       if (ret != 0)
+               printk(KERN_INFO "crypt_s390: sha256_s390 couldn't be loaded.");
+       return ret;
+}
+
+static void __exit fini(void)
+{
+       crypto_unregister_alg(&alg);
+}
+
+module_init(init);
+module_exit(fini);
+
+MODULE_ALIAS("sha256");
+
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("SHA256 Secure Hash Algorithm");