1 files changed, 239 insertions, 0 deletions
diff --git a/drivers/staging/skein/skein_api.c b/drivers/staging/skein/skein_api.c
new file mode 100644
index 000000000000..6e700eefc00c
--- /dev/null
+++ b/drivers/staging/skein/skein_api.c
@@ -0,0 +1,239 @@
+/*
+Copyright (c) 2010 Werner Dittmann
+
+Permission is hereby granted, free of charge, to any person
+obtaining a copy of this software and associated documentation
+files (the "Software"), to deal in the Software without
+restriction, including without limitation the rights to use,
+copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the
+Software is furnished to do so, subject to the following
+conditions:
+
+The above copyright notice and this permission notice shall be
+included in all copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
+OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
+HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
+WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
+OTHER DEALINGS IN THE SOFTWARE.
+
+*/
+
+#include <linux/string.h>
+#include "skein_api.h"
+
+int skein_ctx_prepare(struct skein_ctx *ctx, enum skein_size size)
+{
+	skein_assert_ret(ctx && size, SKEIN_FAIL);
+
+	memset(ctx , 0, sizeof(struct skein_ctx));
+	ctx->skein_size = size;
+
+	return SKEIN_SUCCESS;
+}
+
+int skein_init(struct skein_ctx *ctx, size_t hash_bit_len)
+{
+	int ret = SKEIN_FAIL;
+	size_t x_len = 0;
+	u64 *x = NULL;
+	u64 tree_info = SKEIN_CFG_TREE_INFO_SEQUENTIAL;
+
+	skein_assert_ret(ctx, SKEIN_FAIL);
+	/*
+	 * The following two lines rely of the fact that the real Skein
+	 * contexts are a union in out context and thus have tha maximum
+	 * memory available.  The beauty of C :-) .
+	 */
+	x = ctx->m.s256.x;
+	x_len = ctx->skein_size/8;
+	/*
+	 * If size is the same and hash bit length is zero then reuse
+	 * the save chaining variables.
+	 */
+	switch (ctx->skein_size) {
+	case SKEIN_256:
+		ret = skein_256_init_ext(&ctx->m.s256, hash_bit_len,
+					 tree_info, NULL, 0);
+		break;
+	case SKEIN_512:
+		ret = skein_512_init_ext(&ctx->m.s512, hash_bit_len,
+					 tree_info, NULL, 0);
+		break;
+	case SKEIN_1024:
+		ret = skein_1024_init_ext(&ctx->m.s1024, hash_bit_len,
+					  tree_info, NULL, 0);
+		break;
+	}
+
+	if (ret == SKEIN_SUCCESS) {
+		/*
+		 * Save chaining variables for this combination of size and
+		 * hash_bit_len
+		 */
+		memcpy(ctx->x_save, x, x_len);
+	}
+	return ret;
+}
+
+int skein_mac_init(struct skein_ctx *ctx, const u8 *key, size_t key_len,
+		   size_t hash_bit_len)
+{
+	int ret = SKEIN_FAIL;
+	u64 *x = NULL;
+	size_t x_len = 0;
+	u64 tree_info = SKEIN_CFG_TREE_INFO_SEQUENTIAL;
+
+	skein_assert_ret(ctx, SKEIN_FAIL);
+
+	x = ctx->m.s256.x;
+	x_len = ctx->skein_size/8;
+
+	skein_assert_ret(hash_bit_len, SKEIN_BAD_HASHLEN);
+
+	switch (ctx->skein_size) {
+	case SKEIN_256:
+		ret = skein_256_init_ext(&ctx->m.s256, hash_bit_len,
+					 tree_info,
+					 (const u8 *)key, key_len);
+
+		break;
+	case SKEIN_512:
+		ret = skein_512_init_ext(&ctx->m.s512, hash_bit_len,
+					 tree_info,
+					 (const u8 *)key, key_len);
+		break;
+	case SKEIN_1024:
+		ret = skein_1024_init_ext(&ctx->m.s1024, hash_bit_len,
+					  tree_info,
+					  (const u8 *)key, key_len);
+
+		break;
+	}
+	if (ret == SKEIN_SUCCESS) {
+		/*
+		 * Save chaining variables for this combination of key,
+		 * key_len, hash_bit_len
+		 */
+		memcpy(ctx->x_save, x, x_len);
+	}
+	return ret;
+}
+
+void skein_reset(struct skein_ctx *ctx)
+{
+	size_t x_len = 0;
+	u64 *x = NULL;
+
+	/*
+	 * The following two lines rely of the fact that the real Skein
+	 * contexts are a union in out context and thus have tha maximum
+	 * memory available.  The beautiy of C :-) .
+	 */
+	x = ctx->m.s256.x;
+	x_len = ctx->skein_size/8;
+	/* Restore the chaing variable, reset byte counter */
+	memcpy(x, ctx->x_save, x_len);
+
+	/* Setup context to process the message */
+	skein_start_new_type(&ctx->m, MSG);
+}
+
+int skein_update(struct skein_ctx *ctx, const u8 *msg,
+		 size_t msg_byte_cnt)
+{
+	int ret = SKEIN_FAIL;
+
+	skein_assert_ret(ctx, SKEIN_FAIL);
+
+	switch (ctx->skein_size) {
+	case SKEIN_256:
+		ret = skein_256_update(&ctx->m.s256, (const u8 *)msg,
+				       msg_byte_cnt);
+		break;
+	case SKEIN_512:
+		ret = skein_512_update(&ctx->m.s512, (const u8 *)msg,
+				       msg_byte_cnt);
+		break;
+	case SKEIN_1024:
+		ret = skein_1024_update(&ctx->m.s1024, (const u8 *)msg,
+					msg_byte_cnt);
+		break;
+	}
+	return ret;
+
+}
+
+int skein_update_bits(struct skein_ctx *ctx, const u8 *msg,
+		      size_t msg_bit_cnt)
+{
+	/*
+	 * I've used the bit pad implementation from skein_test.c (see NIST CD)
+	 * and modified it to use the convenience functions and added some
+	 * pointer arithmetic.
+	 */
+	size_t length;
+	u8 mask;
+	u8 *up;
+
+	/*
+	 * only the final Update() call is allowed do partial bytes, else
+	 * assert an error
+	 */
+	skein_assert_ret((ctx->m.h.T[1] & SKEIN_T1_FLAG_BIT_PAD) == 0 ||
+			 msg_bit_cnt == 0, SKEIN_FAIL);
+
+	/* if number of bits is a multiple of bytes - that's easy */
+	if ((msg_bit_cnt & 0x7) == 0)
+		return skein_update(ctx, msg, msg_bit_cnt >> 3);
+
+	skein_update(ctx, msg, (msg_bit_cnt >> 3) + 1);
+
+	/*
+	 * The next line rely on the fact that the real Skein contexts
+	 * are a union in our context. After the addition the pointer points to
+	 * Skein's real partial block buffer.
+	 * If this layout ever changes we have to adapt this as well.
+	 */
+	up = (u8 *)ctx->m.s256.x + ctx->skein_size / 8;
+
+	/* set tweak flag for the skein_final call */
+	skein_set_bit_pad_flag(ctx->m.h);
+
+	/* now "pad" the final partial byte the way NIST likes */
+	/* get the b_cnt value (same location for all block sizes) */
+	length = ctx->m.h.b_cnt;
+	/* internal sanity check: there IS a partial byte in the buffer! */
+	skein_assert(length != 0);
+	/* partial byte bit mask */
+	mask = (u8) (1u << (7 - (msg_bit_cnt & 7)));
+	/* apply bit padding on final byte (in the buffer) */
+	up[length-1]  = (u8)((up[length-1] & (0-mask))|mask);
+
+	return SKEIN_SUCCESS;
+}
+
+int skein_final(struct skein_ctx *ctx, u8 *hash)
+{
+	int ret = SKEIN_FAIL;
+
+	skein_assert_ret(ctx, SKEIN_FAIL);
+
+	switch (ctx->skein_size) {
+	case SKEIN_256:
+		ret = skein_256_final(&ctx->m.s256, (u8 *)hash);
+		break;
+	case SKEIN_512:
+		ret = skein_512_final(&ctx->m.s512, (u8 *)hash);
+		break;
+	case SKEIN_1024:
+		ret = skein_1024_final(&ctx->m.s1024, (u8 *)hash);
+		break;
+	}
+	return ret;
+}