Diff: cyclone_crypto/sha256.c

Revision:

0:8918a71cdbe9

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/cyclone_crypto/sha256.c	Sat Feb 04 18:15:49 2017 +0000
@@ -0,0 +1,294 @@
+/**
+ * @file sha256.c
+ * @brief SHA-256 (Secure Hash Algorithm 256)
+ *
+ * @section License
+ *
+ * Copyright (C) 2010-2017 Oryx Embedded SARL. All rights reserved.
+ *
+ * This file is part of CycloneCrypto Open.
+ *
+ * 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.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+ *
+ * @section Description
+ *
+ * SHA-256 is a secure hash algorithm for computing a condensed representation
+ * of an electronic message. Refer to FIPS 180-4 for more details
+ *
+ * @author Oryx Embedded SARL (www.oryx-embedded.com)
+ * @version 1.7.6
+ **/
+
+//Switch to the appropriate trace level
+#define TRACE_LEVEL CRYPTO_TRACE_LEVEL
+
+//Dependencies
+#include <string.h>
+#include "crypto.h"
+#include "sha256.h"
+
+//Check crypto library configuration
+#if (SHA224_SUPPORT == ENABLED || SHA256_SUPPORT == ENABLED)
+
+//Macro to access the workspace as a circular buffer
+#define W(t) w[(t) & 0x0F]
+
+//SHA-256 auxiliary functions
+#define CH(x, y, z) (((x) & (y)) | (~(x) & (z)))
+#define MAJ(x, y, z) (((x) & (y)) | ((x) & (z)) | ((y) & (z)))
+#define SIGMA1(x) (ROR32(x, 2) ^ ROR32(x, 13) ^ ROR32(x, 22))
+#define SIGMA2(x) (ROR32(x, 6) ^ ROR32(x, 11) ^ ROR32(x, 25))
+#define SIGMA3(x) (ROR32(x, 7) ^ ROR32(x, 18) ^ SHR32(x, 3))
+#define SIGMA4(x) (ROR32(x, 17) ^ ROR32(x, 19) ^ SHR32(x, 10))
+
+//SHA-256 padding
+static const uint8_t padding[64] =
+{
+   0x80, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+   0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+   0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+   0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00
+};
+
+//SHA-256 constants
+static const uint32_t 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
+};
+
+//SHA-256 object identifier (2.16.840.1.101.3.4.2.1)
+static const uint8_t sha256Oid[] = {0x60, 0x86, 0x48, 0x01, 0x65, 0x03, 0x04, 0x02, 0x01};
+
+//Common interface for hash algorithms
+const HashAlgo sha256HashAlgo =
+{
+   "SHA-256",
+   sha256Oid,
+   sizeof(sha256Oid),
+   sizeof(Sha256Context),
+   SHA256_BLOCK_SIZE,
+   SHA256_DIGEST_SIZE,
+   (HashAlgoCompute) sha256Compute,
+   (HashAlgoInit) sha256Init,
+   (HashAlgoUpdate) sha256Update,
+   (HashAlgoFinal) sha256Final
+};
+
+
+/**
+ * @brief Digest a message using SHA-256
+ * @param[in] data Pointer to the message being hashed
+ * @param[in] length Length of the message
+ * @param[out] digest Pointer to the calculated digest
+ * @return Error code
+ **/
+
+error_t sha256Compute(const void *data, size_t length, uint8_t *digest)
+{
+   //Allocate a memory buffer to hold the SHA-256 context
+   Sha256Context *context = cryptoAllocMem(sizeof(Sha256Context));
+   //Failed to allocate memory?
+   if(context == NULL)
+      return ERROR_OUT_OF_MEMORY;
+
+   //Initialize the SHA-256 context
+   sha256Init(context);
+   //Digest the message
+   sha256Update(context, data, length);
+   //Finalize the SHA-256 message digest
+   sha256Final(context, digest);
+
+   //Free previously allocated memory
+   cryptoFreeMem(context);
+   //Successful processing
+   return NO_ERROR;
+}
+
+
+/**
+ * @brief Initialize SHA-256 message digest context
+ * @param[in] context Pointer to the SHA-256 context to initialize
+ **/
+
+void sha256Init(Sha256Context *context)
+{
+   //Set initial hash value
+   context->h[0] = 0x6A09E667;
+   context->h[1] = 0xBB67AE85;
+   context->h[2] = 0x3C6EF372;
+   context->h[3] = 0xA54FF53A;
+   context->h[4] = 0x510E527F;
+   context->h[5] = 0x9B05688C;
+   context->h[6] = 0x1F83D9AB;
+   context->h[7] = 0x5BE0CD19;
+
+   //Number of bytes in the buffer
+   context->size = 0;
+   //Total length of the message
+   context->totalSize = 0;
+}
+
+
+/**
+ * @brief Update the SHA-256 context with a portion of the message being hashed
+ * @param[in] context Pointer to the SHA-256 context
+ * @param[in] data Pointer to the buffer being hashed
+ * @param[in] length Length of the buffer
+ **/
+
+void sha256Update(Sha256Context *context, const void *data, size_t length)
+{
+   size_t n;
+
+   //Process the incoming data
+   while(length > 0)
+   {
+      //The buffer can hold at most 64 bytes
+      n = MIN(length, 64 - context->size);
+
+      //Copy the data to the buffer
+      memcpy(context->buffer + context->size, data, n);
+
+      //Update the SHA-256 context
+      context->size += n;
+      context->totalSize += n;
+      //Advance the data pointer
+      data = (uint8_t *) data + n;
+      //Remaining bytes to process
+      length -= n;
+
+      //Process message in 16-word blocks
+      if(context->size == 64)
+      {
+         //Transform the 16-word block
+         sha256ProcessBlock(context);
+         //Empty the buffer
+         context->size = 0;
+      }
+   }
+}
+
+
+/**
+ * @brief Finish the SHA-256 message digest
+ * @param[in] context Pointer to the SHA-256 context
+ * @param[out] digest Calculated digest (optional parameter)
+ **/
+
+void sha256Final(Sha256Context *context, uint8_t *digest)
+{
+   uint_t i;
+   size_t paddingSize;
+   uint64_t totalSize;
+
+   //Length of the original message (before padding)
+   totalSize = context->totalSize * 8;
+
+   //Pad the message so that its length is congruent to 56 modulo 64
+   if(context->size < 56)
+      paddingSize = 56 - context->size;
+   else
+      paddingSize = 64 + 56 - context->size;
+
+   //Append padding
+   sha256Update(context, padding, paddingSize);
+
+   //Append the length of the original message
+   context->w[14] = htobe32((uint32_t) (totalSize >> 32));
+   context->w[15] = htobe32((uint32_t) totalSize);
+
+   //Calculate the message digest
+   sha256ProcessBlock(context);
+
+   //Convert from host byte order to big-endian byte order
+   for(i = 0; i < 8; i++)
+      context->h[i] = htobe32(context->h[i]);
+
+   //Copy the resulting digest
+   if(digest != NULL)
+      memcpy(digest, context->digest, SHA256_DIGEST_SIZE);
+}
+
+
+/**
+ * @brief Process message in 16-word blocks
+ * @param[in] context Pointer to the SHA-256 context
+ **/
+
+void sha256ProcessBlock(Sha256Context *context)
+{
+   uint_t t;
+   uint32_t temp1;
+   uint32_t temp2;
+
+   //Initialize the 8 working registers
+   uint32_t a = context->h[0];
+   uint32_t b = context->h[1];
+   uint32_t c = context->h[2];
+   uint32_t d = context->h[3];
+   uint32_t e = context->h[4];
+   uint32_t f = context->h[5];
+   uint32_t g = context->h[6];
+   uint32_t h = context->h[7];
+
+   //Process message in 16-word blocks
+   uint32_t *w = context->w;
+
+   //Convert from big-endian byte order to host byte order
+   for(t = 0; t < 16; t++)
+      w[t] = betoh32(w[t]);
+
+   //SHA-256 hash computation (alternate method)
+   for(t = 0; t < 64; t++)
+   {
+      //Prepare the message schedule
+      if(t >= 16)
+         W(t) += SIGMA4(W(t + 14)) + W(t + 9) + SIGMA3(W(t + 1));
+
+      //Calculate T1 and T2
+      temp1 = h + SIGMA2(e) + CH(e, f, g) + k[t] + W(t);
+      temp2 = SIGMA1(a) + MAJ(a, b, c);
+
+      //Update the working registers
+      h = g;
+      g = f;
+      f = e;
+      e = d + temp1;
+      d = c;
+      c = b;
+      b = a;
+      a = temp1 + temp2;
+   }
+
+   //Update the hash value
+   context->h[0] += a;
+   context->h[1] += b;
+   context->h[2] += c;
+   context->h[3] += d;
+   context->h[4] += e;
+   context->h[5] += f;
+   context->h[6] += g;
+   context->h[7] += h;
+}
+
+#endif
+