[CRYPTO] s390: Generic sha_update and sha_final

The sha_{update|final} functions are similar for every sha variant.
Since that is error-prone and redundant replace these functions by
a shared generic implementation for s390.

Signed-off-by: Jan Glauber <jang@linux.vnet.ibm.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

1 files changed, 90 insertions, 0 deletions

diff --git a/arch/s390/crypto/sha_common.c b/arch/s390/crypto/sha_common.c
new file mode 100644
index 0000000..80b6f2b
--- /dev/null
+++ b/arch/s390/crypto/sha_common.c
@@ -0,0 +1,90 @@
+/*
+ * Cryptographic API.
+ *
+ * s390 generic implementation of the SHA Secure Hash Algorithms.
+ *
+ * Copyright IBM Corp. 2007
+ * Author(s): Jan Glauber (jang@de.ibm.com)
+ *
+ * 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/crypto.h>
+#include "sha.h"
+#include "crypt_s390.h"
+
+void s390_sha_update(struct crypto_tfm *tfm, const u8 *data, unsigned int len)
+{
+	struct s390_sha_ctx *ctx = crypto_tfm_ctx(tfm);
+	unsigned int bsize = crypto_tfm_alg_blocksize(tfm);
+	unsigned int index;
+	int ret;
+
+	/* how much is already in the buffer? */
+	index = ctx->count & (bsize - 1);
+	ctx->count += len;
+
+	if ((index + len) < bsize)
+		goto store;
+
+	/* process one stored block */
+	if (index) {
+		memcpy(ctx->buf + index, data, bsize - index);
+		ret = crypt_s390_kimd(ctx->func, ctx->state, ctx->buf, bsize);
+		BUG_ON(ret != bsize);
+		data += bsize - index;
+		len -= bsize - index;
+	}
+
+	/* process as many blocks as possible */
+	if (len >= bsize) {
+		ret = crypt_s390_kimd(ctx->func, ctx->state, data,
+				      len & ~(bsize - 1));
+		BUG_ON(ret != (len & ~(bsize - 1)));
+		data += ret;
+		len -= ret;
+	}
+store:
+	if (len)
+		memcpy(ctx->buf + index , data, len);
+}
+EXPORT_SYMBOL_GPL(s390_sha_update);
+
+void s390_sha_final(struct crypto_tfm *tfm, u8 *out)
+{
+	struct s390_sha_ctx *ctx = crypto_tfm_ctx(tfm);
+	unsigned int bsize = crypto_tfm_alg_blocksize(tfm);
+	u64 bits;
+	unsigned int index, end;
+	int ret;
+
+	/* must perform manual padding */
+	index = ctx->count & (bsize - 1);
+	end = (index < bsize - 8) ? bsize : (2 * bsize);
+
+	/* start pad with 1 */
+	ctx->buf[index] = 0x80;
+	index++;
+
+	/* pad with zeros */
+	memset(ctx->buf + index, 0x00, end - index - 8);
+
+	bits = ctx->count * 8;
+	memcpy(ctx->buf + end - 8, &bits, sizeof(bits));
+
+	ret = crypt_s390_kimd(ctx->func, ctx->state, ctx->buf, end);
+	BUG_ON(ret != end);
+
+	/* copy digest to out */
+	memcpy(out, ctx->state, crypto_hash_digestsize(crypto_hash_cast(tfm)));
+	/* wipe context */
+	memset(ctx, 0, sizeof *ctx);
+}
+EXPORT_SYMBOL_GPL(s390_sha_final);
+
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("s390 SHA cipher common functions");