common/sha256: Move to third_party

The code originally comes from vboot_reference, and is now
found on github: https://github.com/ogay/sha2 .

BRANCH=none
BUG=chromium:884905
TEST=make buildall -j, which also include basic tests.

Change-Id: I8beac95430b2126f625a3981a9ebe038ab588212
Signed-off-by: Nicolas Boichat <drinkcat@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/ec/+/1599763
Reviewed-by: Aseda Aboagye <aaboagye@chromium.org>

4 files changed, 337 insertions, 297 deletions

diff --git a/common/sha256.c b/common/sha256.c
index 2d6eaa43f2..8c0778c3e6 100644..120000
--- a/common/sha256.c
+++ b/common/sha256.c
@@ -1,297 +1 @@
-/* SHA-256 and SHA-512 implementation based on code by Oliver Gay
- * <olivier.gay@a3.epfl.ch> under a BSD-style license. See below.
- */
-
-/*
- * FIPS 180-2 SHA-224/256/384/512 implementation
- * Last update: 02/02/2007
- * Issue date:  04/30/2005
- *
- * Copyright (C) 2005, 2007 Olivier Gay <olivier.gay@a3.epfl.ch>
- * All rights reserved.
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions
- * are met:
- * 1. Redistributions of source code must retain the above copyright
- *    notice, this list of conditions and the following disclaimer.
- * 2. Redistributions in binary form must reproduce the above copyright
- *    notice, this list of conditions and the following disclaimer in the
- *    documentation and/or other materials provided with the distribution.
- * 3. Neither the name of the project nor the names of its contributors
- *    may be used to endorse or promote products derived from this software
- *    without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
- * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
- * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
- * ARE DISCLAIMED.  IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
- * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
- * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
- * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
- * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
- * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
- * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
- * SUCH DAMAGE.
- */
-
-#include "sha256.h"
-#include "util.h"
-
-#define SHFR(x, n)    (x >> n)
-#define ROTR(x, n)   ((x >> n) | (x << ((sizeof(x) << 3) - n)))
-#define ROTL(x, n)   ((x << n) | (x >> ((sizeof(x) << 3) - n)))
-#define CH(x, y, z)  ((x & y) ^ (~x & z))
-#define MAJ(x, y, z) ((x & y) ^ (x & z) ^ (y & z))
-
-#define SHA256_F1(x) (ROTR(x,  2) ^ ROTR(x, 13) ^ ROTR(x, 22))
-#define SHA256_F2(x) (ROTR(x,  6) ^ ROTR(x, 11) ^ ROTR(x, 25))
-#define SHA256_F3(x) (ROTR(x,  7) ^ ROTR(x, 18) ^ SHFR(x,  3))
-#define SHA256_F4(x) (ROTR(x, 17) ^ ROTR(x, 19) ^ SHFR(x, 10))
-
-#define UNPACK32(x, str)				\
-	{						\
-		*((str) + 3) = (uint8_t) ((x));		\
-		*((str) + 2) = (uint8_t) ((x) >>  8);	\
-		*((str) + 1) = (uint8_t) ((x) >> 16);	\
-		*((str) + 0) = (uint8_t) ((x) >> 24);	\
-	}
-
-#define PACK32(str, x)						\
-	{							\
-		*(x) = ((uint32_t) *((str) + 3))		\
-			| ((uint32_t) *((str) + 2) <<  8)	\
-			| ((uint32_t) *((str) + 1) << 16)	\
-			| ((uint32_t) *((str) + 0) << 24);	\
-	}
-
-/* Macros used for loops unrolling */
-
-#define SHA256_SCR(i)						\
-	{							\
-		w[i] =  SHA256_F4(w[i -  2]) + w[i -  7]	\
-			+ SHA256_F3(w[i - 15]) + w[i - 16];	\
-	}
-
-#define SHA256_EXP(a, b, c, d, e, f, g, h, j)				\
-	{								\
-		t1 = wv[h] + SHA256_F2(wv[e]) + CH(wv[e], wv[f], wv[g])	\
-			+ sha256_k[j] + w[j];				\
-		t2 = SHA256_F1(wv[a]) + MAJ(wv[a], wv[b], wv[c]);	\
-		wv[d] += t1;						\
-		wv[h] = t1 + t2;					\
-	}
-
-static const uint32_t sha256_h0[8] = {
-	0x6a09e667, 0xbb67ae85, 0x3c6ef372, 0xa54ff53a,
-	0x510e527f, 0x9b05688c, 0x1f83d9ab, 0x5be0cd19};
-
-static const uint32_t sha256_k[64] = {
-	0x428a2f98, 0x71374491, 0xb5c0fbcf, 0xe9b5dba5,
-	0x3956c25b, 0x59f111f1, 0x923f82a4, 0xab1c5ed5,
-	0xd807aa98, 0x12835b01, 0x243185be, 0x550c7dc3,
-	0x72be5d74, 0x80deb1fe, 0x9bdc06a7, 0xc19bf174,
-	0xe49b69c1, 0xefbe4786, 0x0fc19dc6, 0x240ca1cc,
-	0x2de92c6f, 0x4a7484aa, 0x5cb0a9dc, 0x76f988da,
-	0x983e5152, 0xa831c66d, 0xb00327c8, 0xbf597fc7,
-	0xc6e00bf3, 0xd5a79147, 0x06ca6351, 0x14292967,
-	0x27b70a85, 0x2e1b2138, 0x4d2c6dfc, 0x53380d13,
-	0x650a7354, 0x766a0abb, 0x81c2c92e, 0x92722c85,
-	0xa2bfe8a1, 0xa81a664b, 0xc24b8b70, 0xc76c51a3,
-	0xd192e819, 0xd6990624, 0xf40e3585, 0x106aa070,
-	0x19a4c116, 0x1e376c08, 0x2748774c, 0x34b0bcb5,
-	0x391c0cb3, 0x4ed8aa4a, 0x5b9cca4f, 0x682e6ff3,
-	0x748f82ee, 0x78a5636f, 0x84c87814, 0x8cc70208,
-	0x90befffa, 0xa4506ceb, 0xbef9a3f7, 0xc67178f2};
-
-void SHA256_init(struct sha256_ctx *ctx)
-{
-	int i;
-
-	for (i = 0; i < 8; i++)
-		ctx->h[i] = sha256_h0[i];
-
-	ctx->len = 0;
-	ctx->tot_len = 0;
-}
-
-static void SHA256_transform(struct sha256_ctx *ctx, const uint8_t *message,
-			     unsigned int block_nb)
-{
-	/* Note: this function requires a considerable amount of stack */
-	uint32_t w[64];
-	uint32_t wv[8];
-	uint32_t t1, t2;
-	const unsigned char *sub_block;
-	int i, j;
-
-	for (i = 0; i < (int) block_nb; i++) {
-		sub_block = message + (i << 6);
-
-		for (j = 0; j < 16; j++)
-			PACK32(&sub_block[j << 2], &w[j]);
-
-#ifdef CONFIG_SHA256_UNROLLED
-		for (j = 16; j < 64; j += 8) {
-			SHA256_SCR(j);
-			SHA256_SCR(j+1);
-			SHA256_SCR(j+2);
-			SHA256_SCR(j+3);
-			SHA256_SCR(j+4);
-			SHA256_SCR(j+5);
-			SHA256_SCR(j+6);
-			SHA256_SCR(j+7);
-		}
-#else
-		for (j = 16; j < 64; j++)
-			SHA256_SCR(j);
-#endif
-
-		for (j = 0; j < 8; j++)
-			wv[j] = ctx->h[j];
-
-#ifdef CONFIG_SHA256_UNROLLED
-		for (j = 0; j < 64; j += 8) {
-			SHA256_EXP(0, 1, 2, 3, 4, 5, 6, 7, j);
-			SHA256_EXP(7, 0, 1, 2, 3, 4, 5, 6, j+1);
-			SHA256_EXP(6, 7, 0, 1, 2, 3, 4, 5, j+2);
-			SHA256_EXP(5, 6, 7, 0, 1, 2, 3, 4, j+3);
-			SHA256_EXP(4, 5, 6, 7, 0, 1, 2, 3, j+4);
-			SHA256_EXP(3, 4, 5, 6, 7, 0, 1, 2, j+5);
-			SHA256_EXP(2, 3, 4, 5, 6, 7, 0, 1, j+6);
-			SHA256_EXP(1, 2, 3, 4, 5, 6, 7, 0, j+7);
-		}
-#else
-		for (j = 0; j < 64; j++) {
-			t1 = wv[7] + SHA256_F2(wv[4]) + CH(wv[4], wv[5], wv[6])
-				+ sha256_k[j] + w[j];
-			t2 = SHA256_F1(wv[0]) + MAJ(wv[0], wv[1], wv[2]);
-			wv[7] = wv[6];
-			wv[6] = wv[5];
-			wv[5] = wv[4];
-			wv[4] = wv[3] + t1;
-			wv[3] = wv[2];
-			wv[2] = wv[1];
-			wv[1] = wv[0];
-			wv[0] = t1 + t2;
-		}
-#endif
-
-		for (j = 0; j < 8; j++)
-			ctx->h[j] += wv[j];
-	}
-}
-
-void SHA256_update(struct sha256_ctx *ctx, const uint8_t *data, uint32_t len)
-{
-	unsigned int block_nb;
-	unsigned int new_len, rem_len, tmp_len;
-	const uint8_t *shifted_data;
-
-	tmp_len = SHA256_BLOCK_SIZE - ctx->len;
-	rem_len = len < tmp_len ? len : tmp_len;
-
-	memcpy(&ctx->block[ctx->len], data, rem_len);
-
-	if (ctx->len + len < SHA256_BLOCK_SIZE) {
-		ctx->len += len;
-		return;
-	}
-
-	new_len = len - rem_len;
-	block_nb = new_len / SHA256_BLOCK_SIZE;
-
-	shifted_data = data + rem_len;
-
-	SHA256_transform(ctx, ctx->block, 1);
-	SHA256_transform(ctx, shifted_data, block_nb);
-
-	rem_len = new_len % SHA256_BLOCK_SIZE;
-
-	memcpy(ctx->block, &shifted_data[block_nb << 6], rem_len);
-
-	ctx->len = rem_len;
-	ctx->tot_len += (block_nb + 1) << 6;
-}
-
-/*
- * Specialized SHA256_init + SHA256_update that takes the first data block of
- * size SHA256_BLOCK_SIZE as input.
- */
-static void SHA256_init_1b(struct sha256_ctx *ctx, const uint8_t *data)
-{
-	int i;
-
-	for (i = 0; i < 8; i++)
-		ctx->h[i] = sha256_h0[i];
-
-	SHA256_transform(ctx, data, 1);
-
-	ctx->len = 0;
-	ctx->tot_len = SHA256_BLOCK_SIZE;
-}
-
-uint8_t *SHA256_final(struct sha256_ctx *ctx)
-{
-	unsigned int block_nb;
-	unsigned int pm_len;
-	unsigned int len_b;
-	int i;
-
-	block_nb = (1 + ((SHA256_BLOCK_SIZE - 9)
-			 < (ctx->len % SHA256_BLOCK_SIZE)));
-
-	len_b = (ctx->tot_len + ctx->len) << 3;
-	pm_len = block_nb << 6;
-
-	memset(ctx->block + ctx->len, 0, pm_len - ctx->len);
-	ctx->block[ctx->len] = 0x80;
-	UNPACK32(len_b, ctx->block + pm_len - 4);
-
-	SHA256_transform(ctx, ctx->block, block_nb);
-
-	for (i = 0; i < 8; i++)
-		UNPACK32(ctx->h[i], &ctx->buf[i << 2]);
-
-	return ctx->buf;
-}
-
-static void hmac_SHA256_step(uint8_t *output, uint8_t mask,
-			const uint8_t *key, const int key_len,
-			const uint8_t *data, const int data_len) {
-	struct sha256_ctx ctx;
-	uint8_t *key_pad = ctx.block;
-	uint8_t *tmp;
-	int i;
-
-	/* key_pad = key (zero-padded) ^ mask */
-	memset(key_pad, mask, SHA256_BLOCK_SIZE);
-	for (i = 0; i < key_len; i++)
-		key_pad[i] ^= key[i];
-
-	/* tmp = hash(key_pad || message) */
-	SHA256_init_1b(&ctx, key_pad);
-	SHA256_update(&ctx, data, data_len);
-	tmp = SHA256_final(&ctx);
-	memcpy(output, tmp, SHA256_DIGEST_SIZE);
-}
-
-void hmac_SHA256(uint8_t *output, const uint8_t *key, const int key_len,
-		 const uint8_t *message, const int message_len) {
-	/* This code does not support key_len > block_size. */
-	ASSERT(key_len <= SHA256_BLOCK_SIZE);
-
-	/*
-	 * i_key_pad = key (zero-padded) ^ 0x36
-	 * output = hash(i_key_pad || message)
-	 * (Use output as temporary buffer)
-	 */
-	hmac_SHA256_step(output, 0x36, key, key_len, message, message_len);
-
-	/*
-	 * o_key_pad = key (zero-padded) ^ 0x5c
-	 * output = hash(o_key_pad || output)
-	 */
-	hmac_SHA256_step(output, 0x5c,
-			 key, key_len, output, SHA256_DIGEST_SIZE);
-}
+../third_party/sha2//sha256.c
\ No newline at end of file
diff --git a/third_party/sha2/LICENSE b/third_party/sha2/LICENSE
new file mode 100644
index 0000000000..87e21badf3
--- /dev/null
+++ b/third_party/sha2/LICENSE
@@ -0,0 +1,23 @@
+Redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions
+are met:
+1. Redistributions of source code must retain the above copyright
+   notice, this list of conditions and the following disclaimer.
+2. Redistributions in binary form must reproduce the above copyright
+   notice, this list of conditions and the following disclaimer in the
+   documentation and/or other materials provided with the distribution.
+3. Neither the name of the project nor the names of its contributors
+   may be used to endorse or promote products derived from this software
+   without specific prior written permission.
+
+THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
+ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ARE DISCLAIMED.  IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
+FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+SUCH DAMAGE.
\ No newline at end of file
diff --git a/third_party/sha2/METADATA b/third_party/sha2/METADATA
new file mode 100644
index 0000000000..50b90022a9
--- /dev/null
+++ b/third_party/sha2/METADATA
@@ -0,0 +1,16 @@
+name: "SHA-256 implementation"
+description:
+    "Fast software implementation in C of the FIPS 180-2 hash algorithms"
+    "SHA-224, SHA-256, SHA-384 and SHA-512"
+
+third_party {
+  url {
+    type: GIT
+    value: "https://github.com/ogay/sha2"
+  }
+  version: "79116b5d5d449311c27a24e16c99d8bccb4d1301"
+  last_upgrade_date { year: 2014 month: 04 day: 01 }
+  license_type: NOTICE
+  local_modifications: "See git log. "
+    "Created LICENSE file."
+}
\ No newline at end of file
diff --git a/third_party/sha2/sha256.c b/third_party/sha2/sha256.c
new file mode 100644
index 0000000000..2d6eaa43f2
--- /dev/null
+++ b/third_party/sha2/sha256.c
@@ -0,0 +1,297 @@
+/* SHA-256 and SHA-512 implementation based on code by Oliver Gay
+ * <olivier.gay@a3.epfl.ch> under a BSD-style license. See below.
+ */
+
+/*
+ * FIPS 180-2 SHA-224/256/384/512 implementation
+ * Last update: 02/02/2007
+ * Issue date:  04/30/2005
+ *
+ * Copyright (C) 2005, 2007 Olivier Gay <olivier.gay@a3.epfl.ch>
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. Neither the name of the project nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#include "sha256.h"
+#include "util.h"
+
+#define SHFR(x, n)    (x >> n)
+#define ROTR(x, n)   ((x >> n) | (x << ((sizeof(x) << 3) - n)))
+#define ROTL(x, n)   ((x << n) | (x >> ((sizeof(x) << 3) - n)))
+#define CH(x, y, z)  ((x & y) ^ (~x & z))
+#define MAJ(x, y, z) ((x & y) ^ (x & z) ^ (y & z))
+
+#define SHA256_F1(x) (ROTR(x,  2) ^ ROTR(x, 13) ^ ROTR(x, 22))
+#define SHA256_F2(x) (ROTR(x,  6) ^ ROTR(x, 11) ^ ROTR(x, 25))
+#define SHA256_F3(x) (ROTR(x,  7) ^ ROTR(x, 18) ^ SHFR(x,  3))
+#define SHA256_F4(x) (ROTR(x, 17) ^ ROTR(x, 19) ^ SHFR(x, 10))
+
+#define UNPACK32(x, str)				\
+	{						\
+		*((str) + 3) = (uint8_t) ((x));		\
+		*((str) + 2) = (uint8_t) ((x) >>  8);	\
+		*((str) + 1) = (uint8_t) ((x) >> 16);	\
+		*((str) + 0) = (uint8_t) ((x) >> 24);	\
+	}
+
+#define PACK32(str, x)						\
+	{							\
+		*(x) = ((uint32_t) *((str) + 3))		\
+			| ((uint32_t) *((str) + 2) <<  8)	\
+			| ((uint32_t) *((str) + 1) << 16)	\
+			| ((uint32_t) *((str) + 0) << 24);	\
+	}
+
+/* Macros used for loops unrolling */
+
+#define SHA256_SCR(i)						\
+	{							\
+		w[i] =  SHA256_F4(w[i -  2]) + w[i -  7]	\
+			+ SHA256_F3(w[i - 15]) + w[i - 16];	\
+	}
+
+#define SHA256_EXP(a, b, c, d, e, f, g, h, j)				\
+	{								\
+		t1 = wv[h] + SHA256_F2(wv[e]) + CH(wv[e], wv[f], wv[g])	\
+			+ sha256_k[j] + w[j];				\
+		t2 = SHA256_F1(wv[a]) + MAJ(wv[a], wv[b], wv[c]);	\
+		wv[d] += t1;						\
+		wv[h] = t1 + t2;					\
+	}
+
+static const uint32_t sha256_h0[8] = {
+	0x6a09e667, 0xbb67ae85, 0x3c6ef372, 0xa54ff53a,
+	0x510e527f, 0x9b05688c, 0x1f83d9ab, 0x5be0cd19};
+
+static const uint32_t sha256_k[64] = {
+	0x428a2f98, 0x71374491, 0xb5c0fbcf, 0xe9b5dba5,
+	0x3956c25b, 0x59f111f1, 0x923f82a4, 0xab1c5ed5,
+	0xd807aa98, 0x12835b01, 0x243185be, 0x550c7dc3,
+	0x72be5d74, 0x80deb1fe, 0x9bdc06a7, 0xc19bf174,
+	0xe49b69c1, 0xefbe4786, 0x0fc19dc6, 0x240ca1cc,
+	0x2de92c6f, 0x4a7484aa, 0x5cb0a9dc, 0x76f988da,
+	0x983e5152, 0xa831c66d, 0xb00327c8, 0xbf597fc7,
+	0xc6e00bf3, 0xd5a79147, 0x06ca6351, 0x14292967,
+	0x27b70a85, 0x2e1b2138, 0x4d2c6dfc, 0x53380d13,
+	0x650a7354, 0x766a0abb, 0x81c2c92e, 0x92722c85,
+	0xa2bfe8a1, 0xa81a664b, 0xc24b8b70, 0xc76c51a3,
+	0xd192e819, 0xd6990624, 0xf40e3585, 0x106aa070,
+	0x19a4c116, 0x1e376c08, 0x2748774c, 0x34b0bcb5,
+	0x391c0cb3, 0x4ed8aa4a, 0x5b9cca4f, 0x682e6ff3,
+	0x748f82ee, 0x78a5636f, 0x84c87814, 0x8cc70208,
+	0x90befffa, 0xa4506ceb, 0xbef9a3f7, 0xc67178f2};
+
+void SHA256_init(struct sha256_ctx *ctx)
+{
+	int i;
+
+	for (i = 0; i < 8; i++)
+		ctx->h[i] = sha256_h0[i];
+
+	ctx->len = 0;
+	ctx->tot_len = 0;
+}
+
+static void SHA256_transform(struct sha256_ctx *ctx, const uint8_t *message,
+			     unsigned int block_nb)
+{
+	/* Note: this function requires a considerable amount of stack */
+	uint32_t w[64];
+	uint32_t wv[8];
+	uint32_t t1, t2;
+	const unsigned char *sub_block;
+	int i, j;
+
+	for (i = 0; i < (int) block_nb; i++) {
+		sub_block = message + (i << 6);
+
+		for (j = 0; j < 16; j++)
+			PACK32(&sub_block[j << 2], &w[j]);
+
+#ifdef CONFIG_SHA256_UNROLLED
+		for (j = 16; j < 64; j += 8) {
+			SHA256_SCR(j);
+			SHA256_SCR(j+1);
+			SHA256_SCR(j+2);
+			SHA256_SCR(j+3);
+			SHA256_SCR(j+4);
+			SHA256_SCR(j+5);
+			SHA256_SCR(j+6);
+			SHA256_SCR(j+7);
+		}
+#else
+		for (j = 16; j < 64; j++)
+			SHA256_SCR(j);
+#endif
+
+		for (j = 0; j < 8; j++)
+			wv[j] = ctx->h[j];
+
+#ifdef CONFIG_SHA256_UNROLLED
+		for (j = 0; j < 64; j += 8) {
+			SHA256_EXP(0, 1, 2, 3, 4, 5, 6, 7, j);
+			SHA256_EXP(7, 0, 1, 2, 3, 4, 5, 6, j+1);
+			SHA256_EXP(6, 7, 0, 1, 2, 3, 4, 5, j+2);
+			SHA256_EXP(5, 6, 7, 0, 1, 2, 3, 4, j+3);
+			SHA256_EXP(4, 5, 6, 7, 0, 1, 2, 3, j+4);
+			SHA256_EXP(3, 4, 5, 6, 7, 0, 1, 2, j+5);
+			SHA256_EXP(2, 3, 4, 5, 6, 7, 0, 1, j+6);
+			SHA256_EXP(1, 2, 3, 4, 5, 6, 7, 0, j+7);
+		}
+#else
+		for (j = 0; j < 64; j++) {
+			t1 = wv[7] + SHA256_F2(wv[4]) + CH(wv[4], wv[5], wv[6])
+				+ sha256_k[j] + w[j];
+			t2 = SHA256_F1(wv[0]) + MAJ(wv[0], wv[1], wv[2]);
+			wv[7] = wv[6];
+			wv[6] = wv[5];
+			wv[5] = wv[4];
+			wv[4] = wv[3] + t1;
+			wv[3] = wv[2];
+			wv[2] = wv[1];
+			wv[1] = wv[0];
+			wv[0] = t1 + t2;
+		}
+#endif
+
+		for (j = 0; j < 8; j++)
+			ctx->h[j] += wv[j];
+	}
+}
+
+void SHA256_update(struct sha256_ctx *ctx, const uint8_t *data, uint32_t len)
+{
+	unsigned int block_nb;
+	unsigned int new_len, rem_len, tmp_len;
+	const uint8_t *shifted_data;
+
+	tmp_len = SHA256_BLOCK_SIZE - ctx->len;
+	rem_len = len < tmp_len ? len : tmp_len;
+
+	memcpy(&ctx->block[ctx->len], data, rem_len);
+
+	if (ctx->len + len < SHA256_BLOCK_SIZE) {
+		ctx->len += len;
+		return;
+	}
+
+	new_len = len - rem_len;
+	block_nb = new_len / SHA256_BLOCK_SIZE;
+
+	shifted_data = data + rem_len;
+
+	SHA256_transform(ctx, ctx->block, 1);
+	SHA256_transform(ctx, shifted_data, block_nb);
+
+	rem_len = new_len % SHA256_BLOCK_SIZE;
+
+	memcpy(ctx->block, &shifted_data[block_nb << 6], rem_len);
+
+	ctx->len = rem_len;
+	ctx->tot_len += (block_nb + 1) << 6;
+}
+
+/*
+ * Specialized SHA256_init + SHA256_update that takes the first data block of
+ * size SHA256_BLOCK_SIZE as input.
+ */
+static void SHA256_init_1b(struct sha256_ctx *ctx, const uint8_t *data)
+{
+	int i;
+
+	for (i = 0; i < 8; i++)
+		ctx->h[i] = sha256_h0[i];
+
+	SHA256_transform(ctx, data, 1);
+
+	ctx->len = 0;
+	ctx->tot_len = SHA256_BLOCK_SIZE;
+}
+
+uint8_t *SHA256_final(struct sha256_ctx *ctx)
+{
+	unsigned int block_nb;
+	unsigned int pm_len;
+	unsigned int len_b;
+	int i;
+
+	block_nb = (1 + ((SHA256_BLOCK_SIZE - 9)
+			 < (ctx->len % SHA256_BLOCK_SIZE)));
+
+	len_b = (ctx->tot_len + ctx->len) << 3;
+	pm_len = block_nb << 6;
+
+	memset(ctx->block + ctx->len, 0, pm_len - ctx->len);
+	ctx->block[ctx->len] = 0x80;
+	UNPACK32(len_b, ctx->block + pm_len - 4);
+
+	SHA256_transform(ctx, ctx->block, block_nb);
+
+	for (i = 0; i < 8; i++)
+		UNPACK32(ctx->h[i], &ctx->buf[i << 2]);
+
+	return ctx->buf;
+}
+
+static void hmac_SHA256_step(uint8_t *output, uint8_t mask,
+			const uint8_t *key, const int key_len,
+			const uint8_t *data, const int data_len) {
+	struct sha256_ctx ctx;
+	uint8_t *key_pad = ctx.block;
+	uint8_t *tmp;
+	int i;
+
+	/* key_pad = key (zero-padded) ^ mask */
+	memset(key_pad, mask, SHA256_BLOCK_SIZE);
+	for (i = 0; i < key_len; i++)
+		key_pad[i] ^= key[i];
+
+	/* tmp = hash(key_pad || message) */
+	SHA256_init_1b(&ctx, key_pad);
+	SHA256_update(&ctx, data, data_len);
+	tmp = SHA256_final(&ctx);
+	memcpy(output, tmp, SHA256_DIGEST_SIZE);
+}
+
+void hmac_SHA256(uint8_t *output, const uint8_t *key, const int key_len,
+		 const uint8_t *message, const int message_len) {
+	/* This code does not support key_len > block_size. */
+	ASSERT(key_len <= SHA256_BLOCK_SIZE);
+
+	/*
+	 * i_key_pad = key (zero-padded) ^ 0x36
+	 * output = hash(i_key_pad || message)
+	 * (Use output as temporary buffer)
+	 */
+	hmac_SHA256_step(output, 0x36, key, key_len, message, message_len);
+
+	/*
+	 * o_key_pad = key (zero-padded) ^ 0x5c
+	 * output = hash(o_key_pad || output)
+	 */
+	hmac_SHA256_step(output, 0x5c,
+			 key, key_len, output, SHA256_DIGEST_SIZE);
+}