tech-invite   World Map     

IETF     RFCs     Groups     SIP     ABNFs    |    3GPP     Specs     Glossaries     Architecture     IMS     UICC    |    search     info

RFC 6234

 
 
 

US Secure Hash Algorithms (SHA and SHA-based HMAC and HKDF)

Part 3 of 5, p. 30 to 79
Prev RFC Part       Next RFC Part

 


prevText      Top      Up      ToC       Page 30 
8.2.  The SHA Code

   This code is primarily intended as expository reference code and
   could be optimized further.  For example, the assignment rotations
   through the variables a, b, ..., h could be treated as a cycle and
   the loop unrolled, rather than doing the explicit copying.

   Note that there are alternative representations of the Ch() and Maj()
   functions controlled by an ifdef.

8.2.1.  sha1.c

/**************************** sha1.c ***************************/
/***************** See RFC 6234 for details. *******************/
/* Copyright (c) 2011 IETF Trust and the persons identified as */
/* authors of the code.  All rights reserved.                  */
/* See sha.h for terms of use and redistribution.              */

/*
 *  Description:
 *      This file implements the Secure Hash Algorithm SHA-1
 *      as defined in the U.S. National Institute of Standards
 *      and Technology Federal Information Processing Standards
 *      Publication (FIPS PUB) 180-3 published in October 2008
 *      and formerly defined in its predecessors, FIPS PUB 180-1
 *      and FIP PUB 180-2.
 *
 *      A combined document showing all algorithms is available at
 *              http://csrc.nist.gov/publications/fips/
 *                     fips180-3/fips180-3_final.pdf
 *

Top      Up      ToC       Page 31 
 *      The SHA-1 algorithm produces a 160-bit message digest for a
 *      given data stream that can serve as a means of providing a
 *      "fingerprint" for a message.
 *
 *  Portability Issues:
 *      SHA-1 is defined in terms of 32-bit "words".  This code
 *      uses <stdint.h> (included via "sha.h") to define 32- and
 *      8-bit unsigned integer types.  If your C compiler does
 *      not support 32-bit unsigned integers, this code is not
 *      appropriate.
 *
 *  Caveats:
 *      SHA-1 is designed to work with messages less than 2^64 bits
 *      long.  This implementation uses SHA1Input() to hash the bits
 *      that are a multiple of the size of an 8-bit octet, and then
 *      optionally uses SHA1FinalBits() to hash the final few bits of
 *      the input.
 */

#include "sha.h"
#include "sha-private.h"

/*
 *  Define the SHA1 circular left shift macro
 */
#define SHA1_ROTL(bits,word) \
                (((word) << (bits)) | ((word) >> (32-(bits))))

/*
 * Add "length" to the length.
 * Set Corrupted when overflow has occurred.
 */
static uint32_t addTemp;
#define SHA1AddLength(context, length)                     \
    (addTemp = (context)->Length_Low,                      \
     (context)->Corrupted =                                \
        (((context)->Length_Low += (length)) < addTemp) && \
        (++(context)->Length_High == 0) ? shaInputTooLong  \
                                        : (context)->Corrupted )

/* Local Function Prototypes */
static void SHA1ProcessMessageBlock(SHA1Context *context);
static void SHA1Finalize(SHA1Context *context, uint8_t Pad_Byte);
static void SHA1PadMessage(SHA1Context *context, uint8_t Pad_Byte);

Top      Up      ToC       Page 32 
/*
 *  SHA1Reset
 *
 *  Description:
 *      This function will initialize the SHA1Context in preparation
 *      for computing a new SHA1 message digest.
 *
 *  Parameters:
 *      context: [in/out]
 *          The context to reset.
 *
 *  Returns:
 *      sha Error Code.
 *
 */
int SHA1Reset(SHA1Context *context)
{
  if (!context) return shaNull;

  context->Length_High = context->Length_Low = 0;
  context->Message_Block_Index = 0;

  /* Initial Hash Values: FIPS 180-3 section 5.3.1 */
  context->Intermediate_Hash[0]   = 0x67452301;
  context->Intermediate_Hash[1]   = 0xEFCDAB89;
  context->Intermediate_Hash[2]   = 0x98BADCFE;
  context->Intermediate_Hash[3]   = 0x10325476;
  context->Intermediate_Hash[4]   = 0xC3D2E1F0;

  context->Computed   = 0;
  context->Corrupted  = shaSuccess;

  return shaSuccess;
}

/*
 *  SHA1Input
 *
 *  Description:
 *      This function accepts an array of octets as the next portion
 *      of the message.
 *
 *  Parameters:
 *      context: [in/out]
 *          The SHA context to update.
 *      message_array[ ]: [in]
 *          An array of octets representing the next portion of
 *          the message.

Top      Up      ToC       Page 33 
 *      length: [in]
 *          The length of the message in message_array.
 *
 *  Returns:
 *      sha Error Code.
 *
 */
int SHA1Input(SHA1Context *context,
    const uint8_t *message_array, unsigned length)
{
  if (!context) return shaNull;
  if (!length) return shaSuccess;
  if (!message_array) return shaNull;
  if (context->Computed) return context->Corrupted = shaStateError;
  if (context->Corrupted) return context->Corrupted;

  while (length--) {
    context->Message_Block[context->Message_Block_Index++] =
      *message_array;

    if ((SHA1AddLength(context, 8) == shaSuccess) &&
      (context->Message_Block_Index == SHA1_Message_Block_Size))
      SHA1ProcessMessageBlock(context);

    message_array++;
  }

  return context->Corrupted;
}

/*
 * SHA1FinalBits
 *
 * Description:
 *   This function will add in any final bits of the message.
 *
 * Parameters:
 *   context: [in/out]
 *     The SHA context to update.
 *   message_bits: [in]
 *     The final bits of the message, in the upper portion of the
 *     byte.  (Use 0b###00000 instead of 0b00000### to input the
 *     three bits ###.)
 *   length: [in]
 *     The number of bits in message_bits, between 1 and 7.
 *
 * Returns:
 *   sha Error Code.

Top      Up      ToC       Page 34 
 */
int SHA1FinalBits(SHA1Context *context, uint8_t message_bits,
    unsigned int length)
{
  static uint8_t masks[8] = {
      /* 0 0b00000000 */ 0x00, /* 1 0b10000000 */ 0x80,
      /* 2 0b11000000 */ 0xC0, /* 3 0b11100000 */ 0xE0,
      /* 4 0b11110000 */ 0xF0, /* 5 0b11111000 */ 0xF8,
      /* 6 0b11111100 */ 0xFC, /* 7 0b11111110 */ 0xFE
  };

  static uint8_t markbit[8] = {
      /* 0 0b10000000 */ 0x80, /* 1 0b01000000 */ 0x40,
      /* 2 0b00100000 */ 0x20, /* 3 0b00010000 */ 0x10,
      /* 4 0b00001000 */ 0x08, /* 5 0b00000100 */ 0x04,
      /* 6 0b00000010 */ 0x02, /* 7 0b00000001 */ 0x01
  };

  if (!context) return shaNull;
  if (!length) return shaSuccess;
  if (context->Corrupted) return context->Corrupted;
  if (context->Computed) return context->Corrupted = shaStateError;
  if (length >= 8) return context->Corrupted = shaBadParam;

  SHA1AddLength(context, length);
  SHA1Finalize(context,
    (uint8_t) ((message_bits & masks[length]) | markbit[length]));

  return context->Corrupted;
}

/*
 * SHA1Result
 *
 * Description:
 *   This function will return the 160-bit message digest
 *   into the Message_Digest array provided by the caller.
 *   NOTE:
 *    The first octet of hash is stored in the element with index 0,
 *      the last octet of hash in the element with index 19.
 *
 * Parameters:
 *   context: [in/out]
 *     The context to use to calculate the SHA-1 hash.
 *   Message_Digest[ ]: [out]
 *     Where the digest is returned.
 *

Top      Up      ToC       Page 35 
 * Returns:
 *   sha Error Code.
 *
 */
int SHA1Result(SHA1Context *context,
    uint8_t Message_Digest[SHA1HashSize])
{
  int i;

  if (!context) return shaNull;
  if (!Message_Digest) return shaNull;
  if (context->Corrupted) return context->Corrupted;

  if (!context->Computed)
    SHA1Finalize(context, 0x80);

  for (i = 0; i < SHA1HashSize; ++i)
    Message_Digest[i] = (uint8_t) (context->Intermediate_Hash[i>>2]
                                   >> (8 * ( 3 - ( i & 0x03 ) )));

  return shaSuccess;
}

/*
 * SHA1ProcessMessageBlock
 *
 * Description:
 *   This helper function will process the next 512 bits of the
 *   message stored in the Message_Block array.
 *
 * Parameters:
 *   context: [in/out]
 *     The SHA context to update.
 *
 * Returns:
 *   Nothing.
 *
 * Comments:
 *   Many of the variable names in this code, especially the
 *   single character names, were used because those were the
 *   names used in the Secure Hash Standard.
 */
static void SHA1ProcessMessageBlock(SHA1Context *context)
{
  /* Constants defined in FIPS 180-3, section 4.2.1 */
  const uint32_t K[4] = {
      0x5A827999, 0x6ED9EBA1, 0x8F1BBCDC, 0xCA62C1D6
  };

Top      Up      ToC       Page 36 
  int        t;               /* Loop counter */
  uint32_t   temp;            /* Temporary word value */
  uint32_t   W[80];           /* Word sequence */
  uint32_t   A, B, C, D, E;   /* Word buffers */

  /*
   * Initialize the first 16 words in the array W
   */
  for (t = 0; t < 16; t++) {
    W[t]  = ((uint32_t)context->Message_Block[t * 4]) << 24;
    W[t] |= ((uint32_t)context->Message_Block[t * 4 + 1]) << 16;
    W[t] |= ((uint32_t)context->Message_Block[t * 4 + 2]) << 8;
    W[t] |= ((uint32_t)context->Message_Block[t * 4 + 3]);
  }

  for (t = 16; t < 80; t++)
    W[t] = SHA1_ROTL(1, W[t-3] ^ W[t-8] ^ W[t-14] ^ W[t-16]);

  A = context->Intermediate_Hash[0];
  B = context->Intermediate_Hash[1];
  C = context->Intermediate_Hash[2];
  D = context->Intermediate_Hash[3];
  E = context->Intermediate_Hash[4];

  for (t = 0; t < 20; t++) {
    temp = SHA1_ROTL(5,A) + SHA_Ch(B, C, D) + E + W[t] + K[0];
    E = D;
    D = C;
    C = SHA1_ROTL(30,B);
    B = A;
    A = temp;
  }

  for (t = 20; t < 40; t++) {
    temp = SHA1_ROTL(5,A) + SHA_Parity(B, C, D) + E + W[t] + K[1];
    E = D;
    D = C;
    C = SHA1_ROTL(30,B);
    B = A;
    A = temp;
  }

  for (t = 40; t < 60; t++) {
    temp = SHA1_ROTL(5,A) + SHA_Maj(B, C, D) + E + W[t] + K[2];
    E = D;
    D = C;
    C = SHA1_ROTL(30,B);
    B = A;

Top      Up      ToC       Page 37 
    A = temp;
  }

  for (t = 60; t < 80; t++) {
    temp = SHA1_ROTL(5,A) + SHA_Parity(B, C, D) + E + W[t] + K[3];
    E = D;
    D = C;
    C = SHA1_ROTL(30,B);
    B = A;
    A = temp;
  }

  context->Intermediate_Hash[0] += A;
  context->Intermediate_Hash[1] += B;
  context->Intermediate_Hash[2] += C;
  context->Intermediate_Hash[3] += D;
  context->Intermediate_Hash[4] += E;
  context->Message_Block_Index = 0;
}

/*
 * SHA1Finalize
 *
 * Description:
 *   This helper function finishes off the digest calculations.
 *
 * Parameters:
 *   context: [in/out]
 *     The SHA context to update.
 *   Pad_Byte: [in]
 *     The last byte to add to the message block before the 0-padding
 *     and length.  This will contain the last bits of the message
 *     followed by another single bit.  If the message was an
 *     exact multiple of 8-bits long, Pad_Byte will be 0x80.
 *
 * Returns:
 *   sha Error Code.
 *
 */
static void SHA1Finalize(SHA1Context *context, uint8_t Pad_Byte)
{
  int i;
  SHA1PadMessage(context, Pad_Byte);
  /* message may be sensitive, clear it out */
  for (i = 0; i < SHA1_Message_Block_Size; ++i)
    context->Message_Block[i] = 0;
  context->Length_High = 0;     /* and clear length */
  context->Length_Low = 0;

Top      Up      ToC       Page 38 
  context->Computed = 1;
}

/*
 * SHA1PadMessage
 *
 * Description:
 *   According to the standard, the message must be padded to the next
 *   even multiple of 512 bits.  The first padding bit must be a '1'.
 *   The last 64 bits represent the length of the original message.
 *   All bits in between should be 0.  This helper function will pad
 *   the message according to those rules by filling the Message_Block
 *   array accordingly.  When it returns, it can be assumed that the
 *   message digest has been computed.
 *
 * Parameters:
 *   context: [in/out]
 *     The context to pad.
 *   Pad_Byte: [in]
 *     The last byte to add to the message block before the 0-padding
 *     and length.  This will contain the last bits of the message
 *     followed by another single bit.  If the message was an
 *     exact multiple of 8-bits long, Pad_Byte will be 0x80.
 *
 * Returns:
 *   Nothing.
 */
static void SHA1PadMessage(SHA1Context *context, uint8_t Pad_Byte)
{
  /*
   * Check to see if the current message block is too small to hold
   * the initial padding bits and length.  If so, we will pad the
   * block, process it, and then continue padding into a second
   * block.
   */
  if (context->Message_Block_Index >= (SHA1_Message_Block_Size - 8)) {
    context->Message_Block[context->Message_Block_Index++] = Pad_Byte;
    while (context->Message_Block_Index < SHA1_Message_Block_Size)
      context->Message_Block[context->Message_Block_Index++] = 0;

    SHA1ProcessMessageBlock(context);
  } else
    context->Message_Block[context->Message_Block_Index++] = Pad_Byte;

  while (context->Message_Block_Index < (SHA1_Message_Block_Size - 8))
    context->Message_Block[context->Message_Block_Index++] = 0;

Top      Up      ToC       Page 39 
  /*
   * Store the message length as the last 8 octets
   */
  context->Message_Block[56] = (uint8_t) (context->Length_High >> 24);
  context->Message_Block[57] = (uint8_t) (context->Length_High >> 16);
  context->Message_Block[58] = (uint8_t) (context->Length_High >> 8);
  context->Message_Block[59] = (uint8_t) (context->Length_High);
  context->Message_Block[60] = (uint8_t) (context->Length_Low >> 24);
  context->Message_Block[61] = (uint8_t) (context->Length_Low >> 16);
  context->Message_Block[62] = (uint8_t) (context->Length_Low >> 8);
  context->Message_Block[63] = (uint8_t) (context->Length_Low);

  SHA1ProcessMessageBlock(context);
}

8.2.2.  sha224-256.c

/************************* sha224-256.c ************************/
/***************** See RFC 6234 for details. *******************/
/* Copyright (c) 2011 IETF Trust and the persons identified as */
/* authors of the code.  All rights reserved.                  */
/* See sha.h for terms of use and redistribution.              */

/*
 * Description:
 *   This file implements the Secure Hash Algorithms SHA-224 and
 *   SHA-256 as defined in the U.S. National Institute of Standards
 *   and Technology Federal Information Processing Standards
 *   Publication (FIPS PUB) 180-3 published in October 2008
 *   and formerly defined in its predecessors, FIPS PUB 180-1
 *   and FIP PUB 180-2.
 *
 *   A combined document showing all algorithms is available at
 *       http://csrc.nist.gov/publications/fips/
 *              fips180-3/fips180-3_final.pdf
 *
 *   The SHA-224 and SHA-256 algorithms produce 224-bit and 256-bit
 *   message digests for a given data stream.  It should take about
 *   2**n steps to find a message with the same digest as a given
 *   message and 2**(n/2) to find any two messages with the same
 *   digest, when n is the digest size in bits.  Therefore, this
 *   algorithm can serve as a means of providing a
 *   "fingerprint" for a message.
 *
 * Portability Issues:
 *   SHA-224 and SHA-256 are defined in terms of 32-bit "words".
 *   This code uses <stdint.h> (included via "sha.h") to define 32-
 *   and 8-bit unsigned integer types.  If your C compiler does not

Top      Up      ToC       Page 40 
 *   support 32-bit unsigned integers, this code is not
 *   appropriate.
 *
 * Caveats:
 *   SHA-224 and SHA-256 are designed to work with messages less
 *   than 2^64 bits long.  This implementation uses SHA224/256Input()
 *   to hash the bits that are a multiple of the size of an 8-bit
 *   octet, and then optionally uses SHA224/256FinalBits()
 *   to hash the final few bits of the input.
 */

#include "sha.h"
#include "sha-private.h"

/* Define the SHA shift, rotate left, and rotate right macros */
#define SHA256_SHR(bits,word)      ((word) >> (bits))
#define SHA256_ROTL(bits,word)                         \
  (((word) << (bits)) | ((word) >> (32-(bits))))
#define SHA256_ROTR(bits,word)                         \
  (((word) >> (bits)) | ((word) << (32-(bits))))

/* Define the SHA SIGMA and sigma macros */
#define SHA256_SIGMA0(word)   \
  (SHA256_ROTR( 2,word) ^ SHA256_ROTR(13,word) ^ SHA256_ROTR(22,word))
#define SHA256_SIGMA1(word)   \
  (SHA256_ROTR( 6,word) ^ SHA256_ROTR(11,word) ^ SHA256_ROTR(25,word))
#define SHA256_sigma0(word)   \
  (SHA256_ROTR( 7,word) ^ SHA256_ROTR(18,word) ^ SHA256_SHR( 3,word))
#define SHA256_sigma1(word)   \
  (SHA256_ROTR(17,word) ^ SHA256_ROTR(19,word) ^ SHA256_SHR(10,word))

/*
 * Add "length" to the length.
 * Set Corrupted when overflow has occurred.
 */
static uint32_t addTemp;
#define SHA224_256AddLength(context, length)               \
  (addTemp = (context)->Length_Low, (context)->Corrupted = \
    (((context)->Length_Low += (length)) < addTemp) &&     \
    (++(context)->Length_High == 0) ? shaInputTooLong :    \
                                      (context)->Corrupted )

/* Local Function Prototypes */
static int SHA224_256Reset(SHA256Context *context, uint32_t *H0);
static void SHA224_256ProcessMessageBlock(SHA256Context *context);
static void SHA224_256Finalize(SHA256Context *context,
  uint8_t Pad_Byte);
static void SHA224_256PadMessage(SHA256Context *context,

Top      Up      ToC       Page 41 
  uint8_t Pad_Byte);
static int SHA224_256ResultN(SHA256Context *context,
  uint8_t Message_Digest[ ], int HashSize);

/* Initial Hash Values: FIPS 180-3 section 5.3.2 */
static uint32_t SHA224_H0[SHA256HashSize/4] = {
    0xC1059ED8, 0x367CD507, 0x3070DD17, 0xF70E5939,
    0xFFC00B31, 0x68581511, 0x64F98FA7, 0xBEFA4FA4
};

/* Initial Hash Values: FIPS 180-3 section 5.3.3 */
static uint32_t SHA256_H0[SHA256HashSize/4] = {
  0x6A09E667, 0xBB67AE85, 0x3C6EF372, 0xA54FF53A,
  0x510E527F, 0x9B05688C, 0x1F83D9AB, 0x5BE0CD19
};

/*
 * SHA224Reset
 *
 * Description:
 *   This function will initialize the SHA224Context in preparation
 *   for computing a new SHA224 message digest.
 *
 * Parameters:
 *   context: [in/out]
 *     The context to reset.
 *
 * Returns:
 *   sha Error Code.
 */
int SHA224Reset(SHA224Context *context)
{
  return SHA224_256Reset(context, SHA224_H0);
}

/*
 * SHA224Input
 *
 * Description:
 *   This function accepts an array of octets as the next portion
 *   of the message.
 *
 * Parameters:
 *   context: [in/out]
 *     The SHA context to update.
 *   message_array[ ]: [in]
 *     An array of octets representing the next portion of
 *     the message.

Top      Up      ToC       Page 42 
 *   length: [in]
 *     The length of the message in message_array.
 *
 * Returns:
 *   sha Error Code.
 *
 */
int SHA224Input(SHA224Context *context, const uint8_t *message_array,
    unsigned int length)
{
  return SHA256Input(context, message_array, length);
}

/*
 * SHA224FinalBits
 *
 * Description:
 *   This function will add in any final bits of the message.
 *
 * Parameters:
 *   context: [in/out]
 *     The SHA context to update.
 *   message_bits: [in]
 *     The final bits of the message, in the upper portion of the
 *     byte.  (Use 0b###00000 instead of 0b00000### to input the
 *     three bits ###.)
 *   length: [in]
 *     The number of bits in message_bits, between 1 and 7.
 *
 * Returns:
 *   sha Error Code.
 */
int SHA224FinalBits(SHA224Context *context,
                    uint8_t message_bits, unsigned int length)
{
  return SHA256FinalBits(context, message_bits, length);
}

/*
 * SHA224Result
 *
 * Description:
 *   This function will return the 224-bit message digest
 *   into the Message_Digest array provided by the caller.
 *   NOTE:
 *    The first octet of hash is stored in the element with index 0,
 *    the last octet of hash in the element with index 27.
 *

Top      Up      ToC       Page 43 
 * Parameters:
 *   context: [in/out]
 *     The context to use to calculate the SHA hash.
 *   Message_Digest[ ]: [out]
 *     Where the digest is returned.
 *
 * Returns:
 *   sha Error Code.
 */
int SHA224Result(SHA224Context *context,
    uint8_t Message_Digest[SHA224HashSize])
{
  return SHA224_256ResultN(context, Message_Digest, SHA224HashSize);
}

/*
 * SHA256Reset
 *
 * Description:
 *   This function will initialize the SHA256Context in preparation
 *   for computing a new SHA256 message digest.
 *
 * Parameters:
 *   context: [in/out]
 *     The context to reset.
 *
 * Returns:
 *   sha Error Code.
 */
int SHA256Reset(SHA256Context *context)
{
  return SHA224_256Reset(context, SHA256_H0);
}

/*
 * SHA256Input
 *
 * Description:
 *   This function accepts an array of octets as the next portion
 *   of the message.
 *
 * Parameters:
 *   context: [in/out]
 *     The SHA context to update.
 *   message_array[ ]: [in]
 *     An array of octets representing the next portion of
 *     the message.

Top      Up      ToC       Page 44 
 *   length: [in]
 *     The length of the message in message_array.
 *
 * Returns:
 *   sha Error Code.
 */
int SHA256Input(SHA256Context *context, const uint8_t *message_array,
    unsigned int length)
{
  if (!context) return shaNull;
  if (!length) return shaSuccess;
  if (!message_array) return shaNull;
  if (context->Computed) return context->Corrupted = shaStateError;
  if (context->Corrupted) return context->Corrupted;

  while (length--) {
    context->Message_Block[context->Message_Block_Index++] =
            *message_array;

    if ((SHA224_256AddLength(context, 8) == shaSuccess) &&
      (context->Message_Block_Index == SHA256_Message_Block_Size))
      SHA224_256ProcessMessageBlock(context);

    message_array++;
  }

  return context->Corrupted;

}

/*
 * SHA256FinalBits
 *
 * Description:
 *   This function will add in any final bits of the message.
 *
 * Parameters:
 *   context: [in/out]
 *     The SHA context to update.
 *   message_bits: [in]
 *     The final bits of the message, in the upper portion of the
 *     byte.  (Use 0b###00000 instead of 0b00000### to input the
 *     three bits ###.)
 *   length: [in]
 *     The number of bits in message_bits, between 1 and 7.
 *
 * Returns:
 *   sha Error Code.

Top      Up      ToC       Page 45 
 */
int SHA256FinalBits(SHA256Context *context,
                    uint8_t message_bits, unsigned int length)
{
  static uint8_t masks[8] = {
      /* 0 0b00000000 */ 0x00, /* 1 0b10000000 */ 0x80,
      /* 2 0b11000000 */ 0xC0, /* 3 0b11100000 */ 0xE0,
      /* 4 0b11110000 */ 0xF0, /* 5 0b11111000 */ 0xF8,
      /* 6 0b11111100 */ 0xFC, /* 7 0b11111110 */ 0xFE
  };
  static uint8_t markbit[8] = {
      /* 0 0b10000000 */ 0x80, /* 1 0b01000000 */ 0x40,
      /* 2 0b00100000 */ 0x20, /* 3 0b00010000 */ 0x10,
      /* 4 0b00001000 */ 0x08, /* 5 0b00000100 */ 0x04,
      /* 6 0b00000010 */ 0x02, /* 7 0b00000001 */ 0x01
  };

  if (!context) return shaNull;
  if (!length) return shaSuccess;
  if (context->Corrupted) return context->Corrupted;
  if (context->Computed) return context->Corrupted = shaStateError;
  if (length >= 8) return context->Corrupted = shaBadParam;

  SHA224_256AddLength(context, length);
  SHA224_256Finalize(context, (uint8_t)
    ((message_bits & masks[length]) | markbit[length]));

  return context->Corrupted;
}

/*
 * SHA256Result
 *
 * Description:
 *   This function will return the 256-bit message digest
 *   into the Message_Digest array provided by the caller.
 *   NOTE:
 *    The first octet of hash is stored in the element with index 0,
 *    the last octet of hash in the element with index 31.
 *
 * Parameters:
 *   context: [in/out]
 *     The context to use to calculate the SHA hash.
 *   Message_Digest[ ]: [out]
 *     Where the digest is returned.
 *
 * Returns:
 *   sha Error Code.

Top      Up      ToC       Page 46 
 */
int SHA256Result(SHA256Context *context,
                 uint8_t Message_Digest[SHA256HashSize])
{
  return SHA224_256ResultN(context, Message_Digest, SHA256HashSize);
}

/*
 * SHA224_256Reset
 *
 * Description:
 *   This helper function will initialize the SHA256Context in
 *   preparation for computing a new SHA-224 or SHA-256 message digest.
 *
 * Parameters:
 *   context: [in/out]
 *     The context to reset.
 *   H0[ ]: [in]
 *     The initial hash value array to use.
 *
 * Returns:
 *   sha Error Code.
 */
static int SHA224_256Reset(SHA256Context *context, uint32_t *H0)
{
  if (!context) return shaNull;

  context->Length_High = context->Length_Low = 0;
  context->Message_Block_Index  = 0;

  context->Intermediate_Hash[0] = H0[0];
  context->Intermediate_Hash[1] = H0[1];
  context->Intermediate_Hash[2] = H0[2];
  context->Intermediate_Hash[3] = H0[3];
  context->Intermediate_Hash[4] = H0[4];
  context->Intermediate_Hash[5] = H0[5];
  context->Intermediate_Hash[6] = H0[6];
  context->Intermediate_Hash[7] = H0[7];

  context->Computed  = 0;
  context->Corrupted = shaSuccess;

  return shaSuccess;
}

/*
 * SHA224_256ProcessMessageBlock
 *

Top      Up      ToC       Page 47 
 * Description:
 *   This helper function will process the next 512 bits of the
 *   message stored in the Message_Block array.
 *
 * Parameters:
 *   context: [in/out]
 *     The SHA context to update.
 *
 * Returns:
 *   Nothing.
 *
 * Comments:
 *   Many of the variable names in this code, especially the
 *   single character names, were used because those were the
 *   names used in the Secure Hash Standard.
 */
static void SHA224_256ProcessMessageBlock(SHA256Context *context)
{
  /* Constants defined in FIPS 180-3, section 4.2.2 */
  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
  };
  int        t, t4;                   /* Loop counter */
  uint32_t   temp1, temp2;            /* Temporary word value */
  uint32_t   W[64];                   /* Word sequence */
  uint32_t   A, B, C, D, E, F, G, H;  /* Word buffers */

  /*
   * Initialize the first 16 words in the array W
   */
  for (t = t4 = 0; t < 16; t++, t4 += 4)
    W[t] = (((uint32_t)context->Message_Block[t4]) << 24) |
           (((uint32_t)context->Message_Block[t4 + 1]) << 16) |
           (((uint32_t)context->Message_Block[t4 + 2]) << 8) |
           (((uint32_t)context->Message_Block[t4 + 3]));

Top      Up      ToC       Page 48 
  for (t = 16; t < 64; t++)
    W[t] = SHA256_sigma1(W[t-2]) + W[t-7] +
        SHA256_sigma0(W[t-15]) + W[t-16];

  A = context->Intermediate_Hash[0];
  B = context->Intermediate_Hash[1];
  C = context->Intermediate_Hash[2];
  D = context->Intermediate_Hash[3];
  E = context->Intermediate_Hash[4];
  F = context->Intermediate_Hash[5];
  G = context->Intermediate_Hash[6];
  H = context->Intermediate_Hash[7];

  for (t = 0; t < 64; t++) {
    temp1 = H + SHA256_SIGMA1(E) + SHA_Ch(E,F,G) + K[t] + W[t];
    temp2 = SHA256_SIGMA0(A) + SHA_Maj(A,B,C);
    H = G;
    G = F;
    F = E;
    E = D + temp1;
    D = C;
    C = B;
    B = A;
    A = temp1 + temp2;
  }

  context->Intermediate_Hash[0] += A;
  context->Intermediate_Hash[1] += B;
  context->Intermediate_Hash[2] += C;
  context->Intermediate_Hash[3] += D;
  context->Intermediate_Hash[4] += E;
  context->Intermediate_Hash[5] += F;
  context->Intermediate_Hash[6] += G;
  context->Intermediate_Hash[7] += H;

  context->Message_Block_Index = 0;
}

/*
 * SHA224_256Finalize
 *
 * Description:
 *   This helper function finishes off the digest calculations.
 *
 * Parameters:
 *   context: [in/out]
 *     The SHA context to update.
 *   Pad_Byte: [in]

Top      Up      ToC       Page 49 
 *     The last byte to add to the message block before the 0-padding
 *     and length.  This will contain the last bits of the message
 *     followed by another single bit.  If the message was an
 *     exact multiple of 8-bits long, Pad_Byte will be 0x80.
 *
 * Returns:
 *   sha Error Code.
 */
static void SHA224_256Finalize(SHA256Context *context,
    uint8_t Pad_Byte)
{
  int i;
  SHA224_256PadMessage(context, Pad_Byte);
  /* message may be sensitive, so clear it out */
  for (i = 0; i < SHA256_Message_Block_Size; ++i)
    context->Message_Block[i] = 0;
  context->Length_High = 0;     /* and clear length */
  context->Length_Low = 0;
  context->Computed = 1;
}

/*
 * SHA224_256PadMessage
 *
 * Description:
 *   According to the standard, the message must be padded to the next
 *   even multiple of 512 bits.  The first padding bit must be a '1'.
 *   The last 64 bits represent the length of the original message.
 *   All bits in between should be 0.  This helper function will pad
 *   the message according to those rules by filling the
 *   Message_Block array accordingly.  When it returns, it can be
 *   assumed that the message digest has been computed.
 *
 * Parameters:
 *   context: [in/out]
 *     The context to pad.
 *   Pad_Byte: [in]
 *     The last byte to add to the message block before the 0-padding
 *     and length.  This will contain the last bits of the message
 *     followed by another single bit.  If the message was an
 *     exact multiple of 8-bits long, Pad_Byte will be 0x80.
 *
 * Returns:
 *   Nothing.
 */
static void SHA224_256PadMessage(SHA256Context *context,
    uint8_t Pad_Byte)
{

Top      Up      ToC       Page 50 
  /*
   * Check to see if the current message block is too small to hold
   * the initial padding bits and length.  If so, we will pad the
   * block, process it, and then continue padding into a second
   * block.
   */
  if (context->Message_Block_Index >= (SHA256_Message_Block_Size-8)) {
    context->Message_Block[context->Message_Block_Index++] = Pad_Byte;
    while (context->Message_Block_Index < SHA256_Message_Block_Size)
      context->Message_Block[context->Message_Block_Index++] = 0;
    SHA224_256ProcessMessageBlock(context);
  } else
    context->Message_Block[context->Message_Block_Index++] = Pad_Byte;

  while (context->Message_Block_Index < (SHA256_Message_Block_Size-8))
    context->Message_Block[context->Message_Block_Index++] = 0;

  /*
   * Store the message length as the last 8 octets
   */
  context->Message_Block[56] = (uint8_t)(context->Length_High >> 24);
  context->Message_Block[57] = (uint8_t)(context->Length_High >> 16);
  context->Message_Block[58] = (uint8_t)(context->Length_High >> 8);
  context->Message_Block[59] = (uint8_t)(context->Length_High);
  context->Message_Block[60] = (uint8_t)(context->Length_Low >> 24);
  context->Message_Block[61] = (uint8_t)(context->Length_Low >> 16);
  context->Message_Block[62] = (uint8_t)(context->Length_Low >> 8);
  context->Message_Block[63] = (uint8_t)(context->Length_Low);

  SHA224_256ProcessMessageBlock(context);
}

/*
 * SHA224_256ResultN
 *
 * Description:
 *   This helper function will return the 224-bit or 256-bit message
 *   digest into the Message_Digest array provided by the caller.
 *   NOTE:
 *    The first octet of hash is stored in the element with index 0,
 *    the last octet of hash in the element with index 27/31.
 *
 * Parameters:
 *   context: [in/out]
 *     The context to use to calculate the SHA hash.
 *   Message_Digest[ ]: [out]
 *     Where the digest is returned.
 *   HashSize: [in]

Top      Up      ToC       Page 51 
 *     The size of the hash, either 28 or 32.
 *
 * Returns:
 *   sha Error Code.
 */
static int SHA224_256ResultN(SHA256Context *context,
    uint8_t Message_Digest[ ], int HashSize)
{
  int i;

  if (!context) return shaNull;
  if (!Message_Digest) return shaNull;
  if (context->Corrupted) return context->Corrupted;

  if (!context->Computed)
    SHA224_256Finalize(context, 0x80);

  for (i = 0; i < HashSize; ++i)
    Message_Digest[i] = (uint8_t)
      (context->Intermediate_Hash[i>>2] >> 8 * ( 3 - ( i & 0x03 ) ));

  return shaSuccess;
}

8.2.3.  sha384-512.c

/************************* sha384-512.c ************************/
/***************** See RFC 6234 for details. *******************/
/* Copyright (c) 2011 IETF Trust and the persons identified as */
/* authors of the code.  All rights reserved.                  */
/* See sha.h for terms of use and redistribution.              */

/*
 * Description:
 *   This file implements the Secure Hash Algorithms SHA-384 and
 *   SHA-512 as defined in the U.S. National Institute of Standards
 *   and Technology Federal Information Processing Standards
 *   Publication (FIPS PUB) 180-3 published in October 2008
 *   and formerly defined in its predecessors, FIPS PUB 180-1
 *   and FIP PUB 180-2.
 *
 *   A combined document showing all algorithms is available at
 *       http://csrc.nist.gov/publications/fips/
 *              fips180-3/fips180-3_final.pdf
 *
 *   The SHA-384 and SHA-512 algorithms produce 384-bit and 512-bit
 *   message digests for a given data stream.  It should take about
 *   2**n steps to find a message with the same digest as a given

Top      Up      ToC       Page 52 
 *   message and 2**(n/2) to find any two messages with the same
 *   digest, when n is the digest size in bits.  Therefore, this
 *   algorithm can serve as a means of providing a
 *   "fingerprint" for a message.
 *
 * Portability Issues:
 *   SHA-384 and SHA-512 are defined in terms of 64-bit "words",
 *   but if USE_32BIT_ONLY is #defined, this code is implemented in
 *   terms of 32-bit "words".  This code uses <stdint.h> (included
 *   via "sha.h") to define the 64-, 32- and 8-bit unsigned integer
 *   types.  If your C compiler does not support 64-bit unsigned
 *   integers and you do not #define USE_32BIT_ONLY, this code is
 *   not appropriate.
 *
 * Caveats:
 *   SHA-384 and SHA-512 are designed to work with messages less
 *   than 2^128 bits long.  This implementation uses SHA384/512Input()
 *   to hash the bits that are a multiple of the size of an 8-bit
 *   octet, and then optionally uses SHA384/256FinalBits()
 *   to hash the final few bits of the input.
 *
 */

#include "sha.h"

#ifdef USE_32BIT_ONLY
/*
 * Define 64-bit arithmetic in terms of 32-bit arithmetic.
 * Each 64-bit number is represented in a 2-word array.
 * All macros are defined such that the result is the last parameter.
 */

/*
 * Define shift, rotate left, and rotate right functions
 */
#define SHA512_SHR(bits, word, ret) (                          \
    /* (((uint64_t)((word))) >> (bits)) */                     \
    (ret)[0] = (((bits) < 32) && ((bits) >= 0)) ?              \
      ((word)[0] >> (bits)) : 0,                               \
    (ret)[1] = ((bits) > 32) ? ((word)[0] >> ((bits) - 32)) :  \
      ((bits) == 32) ? (word)[0] :                             \
      ((bits) >= 0) ?                                          \
        (((word)[0] << (32 - (bits))) |                        \
        ((word)[1] >> (bits))) : 0 )

#define SHA512_SHL(bits, word, ret) (                          \
    /* (((uint64_t)(word)) << (bits)) */                       \
    (ret)[0] = ((bits) > 32) ? ((word)[1] << ((bits) - 32)) :  \

Top      Up      ToC       Page 53 
         ((bits) == 32) ? (word)[1] :                          \
         ((bits) >= 0) ?                                       \
           (((word)[0] << (bits)) |                            \
           ((word)[1] >> (32 - (bits)))) :                     \
         0,                                                    \
    (ret)[1] = (((bits) < 32) && ((bits) >= 0)) ?              \
        ((word)[1] << (bits)) : 0 )

/*
 * Define 64-bit OR
 */
#define SHA512_OR(word1, word2, ret) (                         \
    (ret)[0] = (word1)[0] | (word2)[0],                        \
    (ret)[1] = (word1)[1] | (word2)[1] )

/*
 * Define 64-bit XOR
 */
#define SHA512_XOR(word1, word2, ret) (                        \
    (ret)[0] = (word1)[0] ^ (word2)[0],                        \
    (ret)[1] = (word1)[1] ^ (word2)[1] )

/*
 * Define 64-bit AND
 */
#define SHA512_AND(word1, word2, ret) (                        \
    (ret)[0] = (word1)[0] & (word2)[0],                        \
    (ret)[1] = (word1)[1] & (word2)[1] )

/*
 * Define 64-bit TILDA
 */
#define SHA512_TILDA(word, ret)                                \
  ( (ret)[0] = ~(word)[0], (ret)[1] = ~(word)[1] )

/*
 * Define 64-bit ADD
 */
#define SHA512_ADD(word1, word2, ret) (                        \
    (ret)[1] = (word1)[1], (ret)[1] += (word2)[1],             \
    (ret)[0] = (word1)[0] + (word2)[0] + ((ret)[1] < (word1)[1]) )

/*
 * Add the 4word value in word2 to word1.
 */
static uint32_t ADDTO4_temp, ADDTO4_temp2;
#define SHA512_ADDTO4(word1, word2) (                          \
    ADDTO4_temp = (word1)[3],                                  \

Top      Up      ToC       Page 54 
    (word1)[3] += (word2)[3],                                  \
    ADDTO4_temp2 = (word1)[2],                                 \
    (word1)[2] += (word2)[2] + ((word1)[3] < ADDTO4_temp),     \
    ADDTO4_temp = (word1)[1],                                  \
    (word1)[1] += (word2)[1] + ((word1)[2] < ADDTO4_temp2),    \
    (word1)[0] += (word2)[0] + ((word1)[1] < ADDTO4_temp) )

/*
 * Add the 2word value in word2 to word1.
 */
static uint32_t ADDTO2_temp;
#define SHA512_ADDTO2(word1, word2) (                          \
    ADDTO2_temp = (word1)[1],                                  \
    (word1)[1] += (word2)[1],                                  \
    (word1)[0] += (word2)[0] + ((word1)[1] < ADDTO2_temp) )

/*
 * SHA rotate   ((word >> bits) | (word << (64-bits)))
 */
static uint32_t ROTR_temp1[2], ROTR_temp2[2];
#define SHA512_ROTR(bits, word, ret) (                         \
    SHA512_SHR((bits), (word), ROTR_temp1),                    \
    SHA512_SHL(64-(bits), (word), ROTR_temp2),                 \
    SHA512_OR(ROTR_temp1, ROTR_temp2, (ret)) )

/*
 * Define the SHA SIGMA and sigma macros
 *
 *  SHA512_ROTR(28,word) ^ SHA512_ROTR(34,word) ^ SHA512_ROTR(39,word)
 */
static uint32_t SIGMA0_temp1[2], SIGMA0_temp2[2],
  SIGMA0_temp3[2], SIGMA0_temp4[2];
#define SHA512_SIGMA0(word, ret) (                             \
    SHA512_ROTR(28, (word), SIGMA0_temp1),                     \
    SHA512_ROTR(34, (word), SIGMA0_temp2),                     \
    SHA512_ROTR(39, (word), SIGMA0_temp3),                     \
    SHA512_XOR(SIGMA0_temp2, SIGMA0_temp3, SIGMA0_temp4),      \
    SHA512_XOR(SIGMA0_temp1, SIGMA0_temp4, (ret)) )

/*
 * SHA512_ROTR(14,word) ^ SHA512_ROTR(18,word) ^ SHA512_ROTR(41,word)
 */
static uint32_t SIGMA1_temp1[2], SIGMA1_temp2[2],
  SIGMA1_temp3[2], SIGMA1_temp4[2];
#define SHA512_SIGMA1(word, ret) (                             \
    SHA512_ROTR(14, (word), SIGMA1_temp1),                     \
    SHA512_ROTR(18, (word), SIGMA1_temp2),                     \
    SHA512_ROTR(41, (word), SIGMA1_temp3),                     \

Top      Up      ToC       Page 55 
    SHA512_XOR(SIGMA1_temp2, SIGMA1_temp3, SIGMA1_temp4),      \
    SHA512_XOR(SIGMA1_temp1, SIGMA1_temp4, (ret)) )

/*
 * (SHA512_ROTR( 1,word) ^ SHA512_ROTR( 8,word) ^ SHA512_SHR( 7,word))
 */
static uint32_t sigma0_temp1[2], sigma0_temp2[2],
  sigma0_temp3[2], sigma0_temp4[2];
#define SHA512_sigma0(word, ret) (                             \
    SHA512_ROTR( 1, (word), sigma0_temp1),                     \
    SHA512_ROTR( 8, (word), sigma0_temp2),                     \
    SHA512_SHR( 7, (word), sigma0_temp3),                      \
    SHA512_XOR(sigma0_temp2, sigma0_temp3, sigma0_temp4),      \
    SHA512_XOR(sigma0_temp1, sigma0_temp4, (ret)) )

/*
 * (SHA512_ROTR(19,word) ^ SHA512_ROTR(61,word) ^ SHA512_SHR( 6,word))
 */
static uint32_t sigma1_temp1[2], sigma1_temp2[2],
  sigma1_temp3[2], sigma1_temp4[2];
#define SHA512_sigma1(word, ret) (                             \
    SHA512_ROTR(19, (word), sigma1_temp1),                     \
    SHA512_ROTR(61, (word), sigma1_temp2),                     \
    SHA512_SHR( 6, (word), sigma1_temp3),                      \
    SHA512_XOR(sigma1_temp2, sigma1_temp3, sigma1_temp4),      \
    SHA512_XOR(sigma1_temp1, sigma1_temp4, (ret)) )

#ifndef USE_MODIFIED_MACROS
/*
 * These definitions are the ones used in FIPS 180-3, section 4.1.3
 *  Ch(x,y,z)   ((x & y) ^ (~x & z))
 */
static uint32_t Ch_temp1[2], Ch_temp2[2], Ch_temp3[2];
#define SHA_Ch(x, y, z, ret) (                                 \
    SHA512_AND(x, y, Ch_temp1),                                \
    SHA512_TILDA(x, Ch_temp2),                                 \
    SHA512_AND(Ch_temp2, z, Ch_temp3),                         \
    SHA512_XOR(Ch_temp1, Ch_temp3, (ret)) )

/*
 *  Maj(x,y,z)  (((x)&(y)) ^ ((x)&(z)) ^ ((y)&(z)))
 */
static uint32_t Maj_temp1[2], Maj_temp2[2],
  Maj_temp3[2], Maj_temp4[2];
#define SHA_Maj(x, y, z, ret) (                                \
    SHA512_AND(x, y, Maj_temp1),                               \
    SHA512_AND(x, z, Maj_temp2),                               \
    SHA512_AND(y, z, Maj_temp3),                               \

Top      Up      ToC       Page 56 
    SHA512_XOR(Maj_temp2, Maj_temp3, Maj_temp4),               \
    SHA512_XOR(Maj_temp1, Maj_temp4, (ret)) )
#else /* !USE_MODIFIED_MACROS */
/*
 * These definitions are potentially faster equivalents for the ones
 * used in FIPS 180-3, section 4.1.3.
 *   ((x & y) ^ (~x & z)) becomes
 *   ((x & (y ^ z)) ^ z)
 */
#define SHA_Ch(x, y, z, ret) (                                 \
   (ret)[0] = (((x)[0] & ((y)[0] ^ (z)[0])) ^ (z)[0]),         \
   (ret)[1] = (((x)[1] & ((y)[1] ^ (z)[1])) ^ (z)[1]) )

/*
 *   ((x & y) ^ (x & z) ^ (y & z)) becomes
 *   ((x & (y | z)) | (y & z))
 */
#define SHA_Maj(x, y, z, ret) (                                 \
   ret[0] = (((x)[0] & ((y)[0] | (z)[0])) | ((y)[0] & (z)[0])), \
   ret[1] = (((x)[1] & ((y)[1] | (z)[1])) | ((y)[1] & (z)[1])) )
#endif /* USE_MODIFIED_MACROS */

/*
 * Add "length" to the length.
 * Set Corrupted when overflow has occurred.
 */
static uint32_t addTemp[4] = { 0, 0, 0, 0 };
#define SHA384_512AddLength(context, length) (                        \
    addTemp[3] = (length), SHA512_ADDTO4((context)->Length, addTemp), \
    (context)->Corrupted = (((context)->Length[3] < (length)) &&      \
       ((context)->Length[2] == 0) && ((context)->Length[1] == 0) &&  \
       ((context)->Length[0] == 0)) ? shaInputTooLong :               \
                                      (context)->Corrupted )

/* Local Function Prototypes */
static int SHA384_512Reset(SHA512Context *context,
                           uint32_t H0[SHA512HashSize/4]);
static void SHA384_512ProcessMessageBlock(SHA512Context *context);
static void SHA384_512Finalize(SHA512Context *context,
  uint8_t Pad_Byte);
static void SHA384_512PadMessage(SHA512Context *context,
  uint8_t Pad_Byte);
static int SHA384_512ResultN( SHA512Context *context,
  uint8_t Message_Digest[ ], int HashSize);

/* Initial Hash Values: FIPS 180-3 sections 5.3.4 and 5.3.5 */
static uint32_t SHA384_H0[SHA512HashSize/4] = {
    0xCBBB9D5D, 0xC1059ED8, 0x629A292A, 0x367CD507, 0x9159015A,

Top      Up      ToC       Page 57 
    0x3070DD17, 0x152FECD8, 0xF70E5939, 0x67332667, 0xFFC00B31,
    0x8EB44A87, 0x68581511, 0xDB0C2E0D, 0x64F98FA7, 0x47B5481D,
    0xBEFA4FA4
};
static uint32_t SHA512_H0[SHA512HashSize/4] = {
    0x6A09E667, 0xF3BCC908, 0xBB67AE85, 0x84CAA73B, 0x3C6EF372,
    0xFE94F82B, 0xA54FF53A, 0x5F1D36F1, 0x510E527F, 0xADE682D1,
    0x9B05688C, 0x2B3E6C1F, 0x1F83D9AB, 0xFB41BD6B, 0x5BE0CD19,
    0x137E2179
};

#else /* !USE_32BIT_ONLY */

#include "sha-private.h"

/* Define the SHA shift, rotate left and rotate right macros */
#define SHA512_SHR(bits,word)  (((uint64_t)(word)) >> (bits))
#define SHA512_ROTR(bits,word) ((((uint64_t)(word)) >> (bits)) | \
                                (((uint64_t)(word)) << (64-(bits))))

/*
 * Define the SHA SIGMA and sigma macros
 *
 *  SHA512_ROTR(28,word) ^ SHA512_ROTR(34,word) ^ SHA512_ROTR(39,word)
 */
#define SHA512_SIGMA0(word)   \
 (SHA512_ROTR(28,word) ^ SHA512_ROTR(34,word) ^ SHA512_ROTR(39,word))
#define SHA512_SIGMA1(word)   \
 (SHA512_ROTR(14,word) ^ SHA512_ROTR(18,word) ^ SHA512_ROTR(41,word))
#define SHA512_sigma0(word)   \
 (SHA512_ROTR( 1,word) ^ SHA512_ROTR( 8,word) ^ SHA512_SHR( 7,word))
#define SHA512_sigma1(word)   \
 (SHA512_ROTR(19,word) ^ SHA512_ROTR(61,word) ^ SHA512_SHR( 6,word))

/*
 * Add "length" to the length.
 * Set Corrupted when overflow has occurred.
 */
static uint64_t addTemp;
#define SHA384_512AddLength(context, length)                   \
   (addTemp = context->Length_Low, context->Corrupted =        \
    ((context->Length_Low += length) < addTemp) &&             \
    (++context->Length_High == 0) ? shaInputTooLong :          \
                                    (context)->Corrupted)

/* Local Function Prototypes */
static int SHA384_512Reset(SHA512Context *context,
                           uint64_t H0[SHA512HashSize/8]);

Top      Up      ToC       Page 58 
static void SHA384_512ProcessMessageBlock(SHA512Context *context);
static void SHA384_512Finalize(SHA512Context *context,
  uint8_t Pad_Byte);
static void SHA384_512PadMessage(SHA512Context *context,
  uint8_t Pad_Byte);
static int SHA384_512ResultN(SHA512Context *context,
  uint8_t Message_Digest[ ], int HashSize);

/* Initial Hash Values: FIPS 180-3 sections 5.3.4 and 5.3.5 */
static uint64_t SHA384_H0[ ] = {
    0xCBBB9D5DC1059ED8ll, 0x629A292A367CD507ll, 0x9159015A3070DD17ll,
    0x152FECD8F70E5939ll, 0x67332667FFC00B31ll, 0x8EB44A8768581511ll,
    0xDB0C2E0D64F98FA7ll, 0x47B5481DBEFA4FA4ll
};
static uint64_t SHA512_H0[ ] = {
    0x6A09E667F3BCC908ll, 0xBB67AE8584CAA73Bll, 0x3C6EF372FE94F82Bll,
    0xA54FF53A5F1D36F1ll, 0x510E527FADE682D1ll, 0x9B05688C2B3E6C1Fll,
    0x1F83D9ABFB41BD6Bll, 0x5BE0CD19137E2179ll
};

#endif /* USE_32BIT_ONLY */

/*
 * SHA384Reset
 *
 * Description:
 *   This function will initialize the SHA384Context in preparation
 *   for computing a new SHA384 message digest.
 *
 * Parameters:
 *   context: [in/out]
 *     The context to reset.
 *
 * Returns:
 *   sha Error Code.
 *
 */
int SHA384Reset(SHA384Context *context)
{
  return SHA384_512Reset(context, SHA384_H0);
}

/*
 * SHA384Input
 *
 * Description:
 *   This function accepts an array of octets as the next portion
 *   of the message.

Top      Up      ToC       Page 59 
 *
 * Parameters:
 *   context: [in/out]
 *     The SHA context to update.
 *   message_array[ ]: [in]
 *     An array of octets representing the next portion of
 *     the message.
 *   length: [in]
 *     The length of the message in message_array.
 *
 * Returns:
 *   sha Error Code.
 *
 */
int SHA384Input(SHA384Context *context,
    const uint8_t *message_array, unsigned int length)
{
  return SHA512Input(context, message_array, length);
}

/*
 * SHA384FinalBits
 *
 * Description:
 *   This function will add in any final bits of the message.
 *
 * Parameters:
 *   context: [in/out]
 *     The SHA context to update.
 *   message_bits: [in]
 *     The final bits of the message, in the upper portion of the
 *     byte.  (Use 0b###00000 instead of 0b00000### to input the
 *     three bits ###.)
 *   length: [in]
 *     The number of bits in message_bits, between 1 and 7.
 *
 * Returns:
 *   sha Error Code.
 *
 */
int SHA384FinalBits(SHA384Context *context,
                    uint8_t message_bits, unsigned int length)
{
  return SHA512FinalBits(context, message_bits, length);
}

/*
 * SHA384Result

Top      Up      ToC       Page 60 
 *
 * Description:
 *   This function will return the 384-bit message digest
 *   into the Message_Digest array provided by the caller.
 *   NOTE:
 *    The first octet of hash is stored in the element with index 0,
 *    the last octet of hash in the element with index 47.
 *
 * Parameters:
 *   context: [in/out]
 *     The context to use to calculate the SHA hash.
 *   Message_Digest[ ]: [out]
 *     Where the digest is returned.
 *
 * Returns:
 *   sha Error Code.
 *
 */
int SHA384Result(SHA384Context *context,
    uint8_t Message_Digest[SHA384HashSize])
{
  return SHA384_512ResultN(context, Message_Digest, SHA384HashSize);
}

/*
 * SHA512Reset
 *
 * Description:
 *   This function will initialize the SHA512Context in preparation
 *   for computing a new SHA512 message digest.
 *
 * Parameters:
 *   context: [in/out]
 *     The context to reset.
 *
 * Returns:
 *   sha Error Code.
 *
 */
int SHA512Reset(SHA512Context *context)
{
  return SHA384_512Reset(context, SHA512_H0);
}

/*
 * SHA512Input
 *
 * Description:

Top      Up      ToC       Page 61 
 *   This function accepts an array of octets as the next portion
 *   of the message.
 *
 * Parameters:
 *   context: [in/out]
 *     The SHA context to update.
 *   message_array[ ]: [in]
 *     An array of octets representing the next portion of
 *     the message.
 *   length: [in]
 *     The length of the message in message_array.
 *
 * Returns:
 *   sha Error Code.
 *
 */
int SHA512Input(SHA512Context *context,
        const uint8_t *message_array,
        unsigned int length)
{
  if (!context) return shaNull;
  if (!length) return shaSuccess;
  if (!message_array) return shaNull;
  if (context->Computed) return context->Corrupted = shaStateError;
  if (context->Corrupted) return context->Corrupted;

  while (length--) {
    context->Message_Block[context->Message_Block_Index++] =
            *message_array;

    if ((SHA384_512AddLength(context, 8) == shaSuccess) &&
      (context->Message_Block_Index == SHA512_Message_Block_Size))
      SHA384_512ProcessMessageBlock(context);

    message_array++;
  }

  return context->Corrupted;
}

/*
 * SHA512FinalBits
 *
 * Description:
 *   This function will add in any final bits of the message.
 *
 * Parameters:
 *   context: [in/out]

Top      Up      ToC       Page 62 
 *     The SHA context to update.
 *   message_bits: [in]
 *     The final bits of the message, in the upper portion of the
 *     byte.  (Use 0b###00000 instead of 0b00000### to input the
 *     three bits ###.)
 *   length: [in]
 *     The number of bits in message_bits, between 1 and 7.
 *
 * Returns:
 *   sha Error Code.
 *
 */
int SHA512FinalBits(SHA512Context *context,
                    uint8_t message_bits, unsigned int length)
{
  static uint8_t masks[8] = {
      /* 0 0b00000000 */ 0x00, /* 1 0b10000000 */ 0x80,
      /* 2 0b11000000 */ 0xC0, /* 3 0b11100000 */ 0xE0,
      /* 4 0b11110000 */ 0xF0, /* 5 0b11111000 */ 0xF8,
      /* 6 0b11111100 */ 0xFC, /* 7 0b11111110 */ 0xFE
  };
  static uint8_t markbit[8] = {
      /* 0 0b10000000 */ 0x80, /* 1 0b01000000 */ 0x40,
      /* 2 0b00100000 */ 0x20, /* 3 0b00010000 */ 0x10,
      /* 4 0b00001000 */ 0x08, /* 5 0b00000100 */ 0x04,
      /* 6 0b00000010 */ 0x02, /* 7 0b00000001 */ 0x01
  };

  if (!context) return shaNull;
  if (!length) return shaSuccess;
  if (context->Corrupted) return context->Corrupted;
  if (context->Computed) return context->Corrupted = shaStateError;
  if (length >= 8) return context->Corrupted = shaBadParam;

  SHA384_512AddLength(context, length);
  SHA384_512Finalize(context, (uint8_t)
    ((message_bits & masks[length]) | markbit[length]));

  return context->Corrupted;
}

/*
 * SHA512Result
 *
 * Description:
 *   This function will return the 512-bit message digest
 *   into the Message_Digest array provided by the caller.
 *   NOTE:

Top      Up      ToC       Page 63 
 *    The first octet of hash is stored in the element with index 0,
 *    the last octet of hash in the element with index 63.
 *
 * Parameters:
 *   context: [in/out]
 *     The context to use to calculate the SHA hash.
 *   Message_Digest[ ]: [out]
 *     Where the digest is returned.
 *
 * Returns:
 *   sha Error Code.
 *
 */
int SHA512Result(SHA512Context *context,
    uint8_t Message_Digest[SHA512HashSize])
{
  return SHA384_512ResultN(context, Message_Digest, SHA512HashSize);
}

/*
 * SHA384_512Reset
 *
 * Description:
 *   This helper function will initialize the SHA512Context in
 *   preparation for computing a new SHA384 or SHA512 message
 *   digest.
 *
 * Parameters:
 *   context: [in/out]
 *     The context to reset.
 *   H0[ ]: [in]
 *     The initial hash value array to use.
 *
 * Returns:
 *   sha Error Code.
 *
 */
#ifdef USE_32BIT_ONLY
static int SHA384_512Reset(SHA512Context *context,
                           uint32_t H0[SHA512HashSize/4])
#else /* !USE_32BIT_ONLY */
static int SHA384_512Reset(SHA512Context *context,
                           uint64_t H0[SHA512HashSize/8])
#endif /* USE_32BIT_ONLY */
{
  int i;
  if (!context) return shaNull;

Top      Up      ToC       Page 64 
  context->Message_Block_Index = 0;

#ifdef USE_32BIT_ONLY
  context->Length[0] = context->Length[1] =
  context->Length[2] = context->Length[3] = 0;

  for (i = 0; i < SHA512HashSize/4; i++)
    context->Intermediate_Hash[i] = H0[i];
#else /* !USE_32BIT_ONLY */
  context->Length_High = context->Length_Low = 0;

  for (i = 0; i < SHA512HashSize/8; i++)
    context->Intermediate_Hash[i] = H0[i];
#endif /* USE_32BIT_ONLY */

  context->Computed = 0;
  context->Corrupted = shaSuccess;

  return shaSuccess;
}

/*
 * SHA384_512ProcessMessageBlock
 *
 * Description:
 *   This helper function will process the next 1024 bits of the
 *   message stored in the Message_Block array.
 *
 * Parameters:
 *   context: [in/out]
 *     The SHA context to update.
 *
 * Returns:
 *   Nothing.
 *
 * Comments:
 *   Many of the variable names in this code, especially the
 *   single character names, were used because those were the
 *   names used in the Secure Hash Standard.
 *
 *
 */
static void SHA384_512ProcessMessageBlock(SHA512Context *context)
{
#ifdef USE_32BIT_ONLY
  /* Constants defined in FIPS 180-3, section 4.2.3 */
  static const uint32_t K[80*2] = {
      0x428A2F98, 0xD728AE22, 0x71374491, 0x23EF65CD, 0xB5C0FBCF,

Top      Up      ToC       Page 65 
      0xEC4D3B2F, 0xE9B5DBA5, 0x8189DBBC, 0x3956C25B, 0xF348B538,
      0x59F111F1, 0xB605D019, 0x923F82A4, 0xAF194F9B, 0xAB1C5ED5,
      0xDA6D8118, 0xD807AA98, 0xA3030242, 0x12835B01, 0x45706FBE,
      0x243185BE, 0x4EE4B28C, 0x550C7DC3, 0xD5FFB4E2, 0x72BE5D74,
      0xF27B896F, 0x80DEB1FE, 0x3B1696B1, 0x9BDC06A7, 0x25C71235,
      0xC19BF174, 0xCF692694, 0xE49B69C1, 0x9EF14AD2, 0xEFBE4786,
      0x384F25E3, 0x0FC19DC6, 0x8B8CD5B5, 0x240CA1CC, 0x77AC9C65,
      0x2DE92C6F, 0x592B0275, 0x4A7484AA, 0x6EA6E483, 0x5CB0A9DC,
      0xBD41FBD4, 0x76F988DA, 0x831153B5, 0x983E5152, 0xEE66DFAB,
      0xA831C66D, 0x2DB43210, 0xB00327C8, 0x98FB213F, 0xBF597FC7,
      0xBEEF0EE4, 0xC6E00BF3, 0x3DA88FC2, 0xD5A79147, 0x930AA725,
      0x06CA6351, 0xE003826F, 0x14292967, 0x0A0E6E70, 0x27B70A85,
      0x46D22FFC, 0x2E1B2138, 0x5C26C926, 0x4D2C6DFC, 0x5AC42AED,
      0x53380D13, 0x9D95B3DF, 0x650A7354, 0x8BAF63DE, 0x766A0ABB,
      0x3C77B2A8, 0x81C2C92E, 0x47EDAEE6, 0x92722C85, 0x1482353B,
      0xA2BFE8A1, 0x4CF10364, 0xA81A664B, 0xBC423001, 0xC24B8B70,
      0xD0F89791, 0xC76C51A3, 0x0654BE30, 0xD192E819, 0xD6EF5218,
      0xD6990624, 0x5565A910, 0xF40E3585, 0x5771202A, 0x106AA070,
      0x32BBD1B8, 0x19A4C116, 0xB8D2D0C8, 0x1E376C08, 0x5141AB53,
      0x2748774C, 0xDF8EEB99, 0x34B0BCB5, 0xE19B48A8, 0x391C0CB3,
      0xC5C95A63, 0x4ED8AA4A, 0xE3418ACB, 0x5B9CCA4F, 0x7763E373,
      0x682E6FF3, 0xD6B2B8A3, 0x748F82EE, 0x5DEFB2FC, 0x78A5636F,
      0x43172F60, 0x84C87814, 0xA1F0AB72, 0x8CC70208, 0x1A6439EC,
      0x90BEFFFA, 0x23631E28, 0xA4506CEB, 0xDE82BDE9, 0xBEF9A3F7,
      0xB2C67915, 0xC67178F2, 0xE372532B, 0xCA273ECE, 0xEA26619C,
      0xD186B8C7, 0x21C0C207, 0xEADA7DD6, 0xCDE0EB1E, 0xF57D4F7F,
      0xEE6ED178, 0x06F067AA, 0x72176FBA, 0x0A637DC5, 0xA2C898A6,
      0x113F9804, 0xBEF90DAE, 0x1B710B35, 0x131C471B, 0x28DB77F5,
      0x23047D84, 0x32CAAB7B, 0x40C72493, 0x3C9EBE0A, 0x15C9BEBC,
      0x431D67C4, 0x9C100D4C, 0x4CC5D4BE, 0xCB3E42B6, 0x597F299C,
      0xFC657E2A, 0x5FCB6FAB, 0x3AD6FAEC, 0x6C44198C, 0x4A475817
  };
  int     t, t2, t8;                  /* Loop counter */
  uint32_t  temp1[2], temp2[2],       /* Temporary word values */
        temp3[2], temp4[2], temp5[2];
  uint32_t  W[2*80];                  /* Word sequence */
  uint32_t  A[2], B[2], C[2], D[2],   /* Word buffers */
        E[2], F[2], G[2], H[2];

  /* Initialize the first 16 words in the array W */
  for (t = t2 = t8 = 0; t < 16; t++, t8 += 8) {
    W[t2++] = ((((uint32_t)context->Message_Block[t8    ])) << 24) |
              ((((uint32_t)context->Message_Block[t8 + 1])) << 16) |
              ((((uint32_t)context->Message_Block[t8 + 2])) << 8) |
              ((((uint32_t)context->Message_Block[t8 + 3])));
    W[t2++] = ((((uint32_t)context->Message_Block[t8 + 4])) << 24) |
              ((((uint32_t)context->Message_Block[t8 + 5])) << 16) |
              ((((uint32_t)context->Message_Block[t8 + 6])) << 8) |

Top      Up      ToC       Page 66 
              ((((uint32_t)context->Message_Block[t8 + 7])));
  }

  for (t = 16; t < 80; t++, t2 += 2) {
    /* W[t] = SHA512_sigma1(W[t-2]) + W[t-7] +
      SHA512_sigma0(W[t-15]) + W[t-16]; */
    uint32_t *Wt2 = &W[t2-2*2];
    uint32_t *Wt7 = &W[t2-7*2];
    uint32_t *Wt15 = &W[t2-15*2];
    uint32_t *Wt16 = &W[t2-16*2];
    SHA512_sigma1(Wt2, temp1);
    SHA512_ADD(temp1, Wt7, temp2);
    SHA512_sigma0(Wt15, temp1);
    SHA512_ADD(temp1, Wt16, temp3);
    SHA512_ADD(temp2, temp3, &W[t2]);
  }

  A[0] = context->Intermediate_Hash[0];
  A[1] = context->Intermediate_Hash[1];
  B[0] = context->Intermediate_Hash[2];
  B[1] = context->Intermediate_Hash[3];
  C[0] = context->Intermediate_Hash[4];
  C[1] = context->Intermediate_Hash[5];
  D[0] = context->Intermediate_Hash[6];
  D[1] = context->Intermediate_Hash[7];
  E[0] = context->Intermediate_Hash[8];
  E[1] = context->Intermediate_Hash[9];
  F[0] = context->Intermediate_Hash[10];
  F[1] = context->Intermediate_Hash[11];
  G[0] = context->Intermediate_Hash[12];
  G[1] = context->Intermediate_Hash[13];
  H[0] = context->Intermediate_Hash[14];
  H[1] = context->Intermediate_Hash[15];

  for (t = t2 = 0; t < 80; t++, t2 += 2) {
    /*
     * temp1 = H + SHA512_SIGMA1(E) + SHA_Ch(E,F,G) + K[t] + W[t];
     */
    SHA512_SIGMA1(E,temp1);
    SHA512_ADD(H, temp1, temp2);
    SHA_Ch(E,F,G,temp3);
    SHA512_ADD(temp2, temp3, temp4);
    SHA512_ADD(&K[t2], &W[t2], temp5);
    SHA512_ADD(temp4, temp5, temp1);
    /*
     * temp2 = SHA512_SIGMA0(A) + SHA_Maj(A,B,C);
     */
    SHA512_SIGMA0(A,temp3);

Top      Up      ToC       Page 67 
    SHA_Maj(A,B,C,temp4);
    SHA512_ADD(temp3, temp4, temp2);
    H[0] = G[0]; H[1] = G[1];
    G[0] = F[0]; G[1] = F[1];
    F[0] = E[0]; F[1] = E[1];
    SHA512_ADD(D, temp1, E);
    D[0] = C[0]; D[1] = C[1];
    C[0] = B[0]; C[1] = B[1];
    B[0] = A[0]; B[1] = A[1];
    SHA512_ADD(temp1, temp2, A);
  }

  SHA512_ADDTO2(&context->Intermediate_Hash[0], A);
  SHA512_ADDTO2(&context->Intermediate_Hash[2], B);
  SHA512_ADDTO2(&context->Intermediate_Hash[4], C);
  SHA512_ADDTO2(&context->Intermediate_Hash[6], D);
  SHA512_ADDTO2(&context->Intermediate_Hash[8], E);
  SHA512_ADDTO2(&context->Intermediate_Hash[10], F);
  SHA512_ADDTO2(&context->Intermediate_Hash[12], G);
  SHA512_ADDTO2(&context->Intermediate_Hash[14], H);

#else /* !USE_32BIT_ONLY */
  /* Constants defined in FIPS 180-3, section 4.2.3 */
  static const uint64_t K[80] = {
      0x428A2F98D728AE22ll, 0x7137449123EF65CDll, 0xB5C0FBCFEC4D3B2Fll,
      0xE9B5DBA58189DBBCll, 0x3956C25BF348B538ll, 0x59F111F1B605D019ll,
      0x923F82A4AF194F9Bll, 0xAB1C5ED5DA6D8118ll, 0xD807AA98A3030242ll,
      0x12835B0145706FBEll, 0x243185BE4EE4B28Cll, 0x550C7DC3D5FFB4E2ll,
      0x72BE5D74F27B896Fll, 0x80DEB1FE3B1696B1ll, 0x9BDC06A725C71235ll,
      0xC19BF174CF692694ll, 0xE49B69C19EF14AD2ll, 0xEFBE4786384F25E3ll,
      0x0FC19DC68B8CD5B5ll, 0x240CA1CC77AC9C65ll, 0x2DE92C6F592B0275ll,
      0x4A7484AA6EA6E483ll, 0x5CB0A9DCBD41FBD4ll, 0x76F988DA831153B5ll,
      0x983E5152EE66DFABll, 0xA831C66D2DB43210ll, 0xB00327C898FB213Fll,
      0xBF597FC7BEEF0EE4ll, 0xC6E00BF33DA88FC2ll, 0xD5A79147930AA725ll,
      0x06CA6351E003826Fll, 0x142929670A0E6E70ll, 0x27B70A8546D22FFCll,
      0x2E1B21385C26C926ll, 0x4D2C6DFC5AC42AEDll, 0x53380D139D95B3DFll,
      0x650A73548BAF63DEll, 0x766A0ABB3C77B2A8ll, 0x81C2C92E47EDAEE6ll,
      0x92722C851482353Bll, 0xA2BFE8A14CF10364ll, 0xA81A664BBC423001ll,
      0xC24B8B70D0F89791ll, 0xC76C51A30654BE30ll, 0xD192E819D6EF5218ll,
      0xD69906245565A910ll, 0xF40E35855771202All, 0x106AA07032BBD1B8ll,
      0x19A4C116B8D2D0C8ll, 0x1E376C085141AB53ll, 0x2748774CDF8EEB99ll,
      0x34B0BCB5E19B48A8ll, 0x391C0CB3C5C95A63ll, 0x4ED8AA4AE3418ACBll,
      0x5B9CCA4F7763E373ll, 0x682E6FF3D6B2B8A3ll, 0x748F82EE5DEFB2FCll,
      0x78A5636F43172F60ll, 0x84C87814A1F0AB72ll, 0x8CC702081A6439ECll,
      0x90BEFFFA23631E28ll, 0xA4506CEBDE82BDE9ll, 0xBEF9A3F7B2C67915ll,
      0xC67178F2E372532Bll, 0xCA273ECEEA26619Cll, 0xD186B8C721C0C207ll,
      0xEADA7DD6CDE0EB1Ell, 0xF57D4F7FEE6ED178ll, 0x06F067AA72176FBAll,
      0x0A637DC5A2C898A6ll, 0x113F9804BEF90DAEll, 0x1B710B35131C471Bll,

Top      Up      ToC       Page 68 
      0x28DB77F523047D84ll, 0x32CAAB7B40C72493ll, 0x3C9EBE0A15C9BEBCll,
      0x431D67C49C100D4Cll, 0x4CC5D4BECB3E42B6ll, 0x597F299CFC657E2All,
      0x5FCB6FAB3AD6FAECll, 0x6C44198C4A475817ll
  };
  int        t, t8;                   /* Loop counter */
  uint64_t   temp1, temp2;            /* Temporary word value */
  uint64_t   W[80];                   /* Word sequence */
  uint64_t   A, B, C, D, E, F, G, H;  /* Word buffers */

  /*
   * Initialize the first 16 words in the array W
   */
  for (t = t8 = 0; t < 16; t++, t8 += 8)
    W[t] = ((uint64_t)(context->Message_Block[t8  ]) << 56) |
           ((uint64_t)(context->Message_Block[t8 + 1]) << 48) |
           ((uint64_t)(context->Message_Block[t8 + 2]) << 40) |
           ((uint64_t)(context->Message_Block[t8 + 3]) << 32) |
           ((uint64_t)(context->Message_Block[t8 + 4]) << 24) |
           ((uint64_t)(context->Message_Block[t8 + 5]) << 16) |
           ((uint64_t)(context->Message_Block[t8 + 6]) << 8) |
           ((uint64_t)(context->Message_Block[t8 + 7]));

  for (t = 16; t < 80; t++)
    W[t] = SHA512_sigma1(W[t-2]) + W[t-7] +
        SHA512_sigma0(W[t-15]) + W[t-16];
  A = context->Intermediate_Hash[0];
  B = context->Intermediate_Hash[1];
  C = context->Intermediate_Hash[2];
  D = context->Intermediate_Hash[3];
  E = context->Intermediate_Hash[4];
  F = context->Intermediate_Hash[5];
  G = context->Intermediate_Hash[6];
  H = context->Intermediate_Hash[7];

  for (t = 0; t < 80; t++) {
    temp1 = H + SHA512_SIGMA1(E) + SHA_Ch(E,F,G) + K[t] + W[t];
    temp2 = SHA512_SIGMA0(A) + SHA_Maj(A,B,C);
    H = G;
    G = F;
    F = E;
    E = D + temp1;
    D = C;
    C = B;
    B = A;
    A = temp1 + temp2;
  }

  context->Intermediate_Hash[0] += A;

Top      Up      ToC       Page 69 
  context->Intermediate_Hash[1] += B;
  context->Intermediate_Hash[2] += C;
  context->Intermediate_Hash[3] += D;
  context->Intermediate_Hash[4] += E;
  context->Intermediate_Hash[5] += F;
  context->Intermediate_Hash[6] += G;
  context->Intermediate_Hash[7] += H;
#endif /* USE_32BIT_ONLY */

  context->Message_Block_Index = 0;
}

/*
 * SHA384_512Finalize
 *
 * Description:
 *   This helper function finishes off the digest calculations.
 *
 * Parameters:
 *   context: [in/out]
 *     The SHA context to update.
 *   Pad_Byte: [in]
 *     The last byte to add to the message block before the 0-padding
 *     and length.  This will contain the last bits of the message
 *     followed by another single bit.  If the message was an
 *     exact multiple of 8-bits long, Pad_Byte will be 0x80.
 *
 * Returns:
 *   sha Error Code.
 *
 */
static void SHA384_512Finalize(SHA512Context *context,
    uint8_t Pad_Byte)
{
  int_least16_t i;
  SHA384_512PadMessage(context, Pad_Byte);
  /* message may be sensitive, clear it out */
  for (i = 0; i < SHA512_Message_Block_Size; ++i)
    context->Message_Block[i] = 0;
#ifdef USE_32BIT_ONLY    /* and clear length */
  context->Length[0] = context->Length[1] = 0;
  context->Length[2] = context->Length[3] = 0;
#else /* !USE_32BIT_ONLY */
  context->Length_High = context->Length_Low = 0;
#endif /* USE_32BIT_ONLY */
  context->Computed = 1;
}

Top      Up      ToC       Page 70 
/*
 * SHA384_512PadMessage
 *
 * Description:
 *   According to the standard, the message must be padded to the next
 *   even multiple of 1024 bits.  The first padding bit must be a '1'.
 *   The last 128 bits represent the length of the original message.
 *   All bits in between should be 0.  This helper function will
 *   pad the message according to those rules by filling the
 *   Message_Block array accordingly.  When it returns, it can be
 *   assumed that the message digest has been computed.
 *
 * Parameters:
 *   context: [in/out]
 *     The context to pad.
 *   Pad_Byte: [in]
 *     The last byte to add to the message block before the 0-padding
 *     and length.  This will contain the last bits of the message
 *     followed by another single bit.  If the message was an
 *     exact multiple of 8-bits long, Pad_Byte will be 0x80.
 *
 * Returns:
 *   Nothing.
 *
 */
static void SHA384_512PadMessage(SHA512Context *context,
    uint8_t Pad_Byte)
{
  /*
   * Check to see if the current message block is too small to hold
   * the initial padding bits and length.  If so, we will pad the
   * block, process it, and then continue padding into a second
   * block.
   */
  if (context->Message_Block_Index >= (SHA512_Message_Block_Size-16)) {
    context->Message_Block[context->Message_Block_Index++] = Pad_Byte;
    while (context->Message_Block_Index < SHA512_Message_Block_Size)
      context->Message_Block[context->Message_Block_Index++] = 0;

    SHA384_512ProcessMessageBlock(context);
  } else
    context->Message_Block[context->Message_Block_Index++] = Pad_Byte;

  while (context->Message_Block_Index < (SHA512_Message_Block_Size-16))
    context->Message_Block[context->Message_Block_Index++] = 0;

  /*
   * Store the message length as the last 16 octets

Top      Up      ToC       Page 71 
   */
#ifdef USE_32BIT_ONLY
  context->Message_Block[112] = (uint8_t)(context->Length[0] >> 24);
  context->Message_Block[113] = (uint8_t)(context->Length[0] >> 16);
  context->Message_Block[114] = (uint8_t)(context->Length[0] >> 8);
  context->Message_Block[115] = (uint8_t)(context->Length[0]);
  context->Message_Block[116] = (uint8_t)(context->Length[1] >> 24);
  context->Message_Block[117] = (uint8_t)(context->Length[1] >> 16);
  context->Message_Block[118] = (uint8_t)(context->Length[1] >> 8);
  context->Message_Block[119] = (uint8_t)(context->Length[1]);

  context->Message_Block[120] = (uint8_t)(context->Length[2] >> 24);
  context->Message_Block[121] = (uint8_t)(context->Length[2] >> 16);
  context->Message_Block[122] = (uint8_t)(context->Length[2] >> 8);
  context->Message_Block[123] = (uint8_t)(context->Length[2]);
  context->Message_Block[124] = (uint8_t)(context->Length[3] >> 24);
  context->Message_Block[125] = (uint8_t)(context->Length[3] >> 16);
  context->Message_Block[126] = (uint8_t)(context->Length[3] >> 8);
  context->Message_Block[127] = (uint8_t)(context->Length[3]);
#else /* !USE_32BIT_ONLY */
  context->Message_Block[112] = (uint8_t)(context->Length_High >> 56);
  context->Message_Block[113] = (uint8_t)(context->Length_High >> 48);
  context->Message_Block[114] = (uint8_t)(context->Length_High >> 40);
  context->Message_Block[115] = (uint8_t)(context->Length_High >> 32);
  context->Message_Block[116] = (uint8_t)(context->Length_High >> 24);
  context->Message_Block[117] = (uint8_t)(context->Length_High >> 16);
  context->Message_Block[118] = (uint8_t)(context->Length_High >> 8);
  context->Message_Block[119] = (uint8_t)(context->Length_High);

  context->Message_Block[120] = (uint8_t)(context->Length_Low >> 56);
  context->Message_Block[121] = (uint8_t)(context->Length_Low >> 48);
  context->Message_Block[122] = (uint8_t)(context->Length_Low >> 40);
  context->Message_Block[123] = (uint8_t)(context->Length_Low >> 32);
  context->Message_Block[124] = (uint8_t)(context->Length_Low >> 24);
  context->Message_Block[125] = (uint8_t)(context->Length_Low >> 16);
  context->Message_Block[126] = (uint8_t)(context->Length_Low >> 8);
  context->Message_Block[127] = (uint8_t)(context->Length_Low);
#endif /* USE_32BIT_ONLY */

  SHA384_512ProcessMessageBlock(context);
}

/*
 * SHA384_512ResultN
 *
 * Description:
 *   This helper function will return the 384-bit or 512-bit message
 *   digest into the Message_Digest array provided by the caller.

Top      Up      ToC       Page 72 
 *   NOTE:
 *    The first octet of hash is stored in the element with index 0,
 *    the last octet of hash in the element with index 47/63.
 *
 * Parameters:
 *   context: [in/out]
 *     The context to use to calculate the SHA hash.
 *   Message_Digest[ ]: [out]
 *     Where the digest is returned.
 *   HashSize: [in]
 *     The size of the hash, either 48 or 64.
 *
 * Returns:
 *   sha Error Code.
 *
 */
static int SHA384_512ResultN(SHA512Context *context,
    uint8_t Message_Digest[ ], int HashSize)
{
  int i;
#ifdef USE_32BIT_ONLY
  int i2;
#endif /* USE_32BIT_ONLY */

  if (!context) return shaNull;
  if (!Message_Digest) return shaNull;
  if (context->Corrupted) return context->Corrupted;

  if (!context->Computed)
    SHA384_512Finalize(context, 0x80);

#ifdef USE_32BIT_ONLY
  for (i = i2 = 0; i < HashSize; ) {
    Message_Digest[i++]=(uint8_t)(context->Intermediate_Hash[i2]>>24);
    Message_Digest[i++]=(uint8_t)(context->Intermediate_Hash[i2]>>16);
    Message_Digest[i++]=(uint8_t)(context->Intermediate_Hash[i2]>>8);
    Message_Digest[i++]=(uint8_t)(context->Intermediate_Hash[i2++]);
    Message_Digest[i++]=(uint8_t)(context->Intermediate_Hash[i2]>>24);
    Message_Digest[i++]=(uint8_t)(context->Intermediate_Hash[i2]>>16);
    Message_Digest[i++]=(uint8_t)(context->Intermediate_Hash[i2]>>8);
    Message_Digest[i++]=(uint8_t)(context->Intermediate_Hash[i2++]);
  }
#else /* !USE_32BIT_ONLY */
  for (i = 0; i < HashSize; ++i)
    Message_Digest[i] = (uint8_t)
      (context->Intermediate_Hash[i>>3] >> 8 * ( 7 - ( i % 8 ) ));
#endif /* USE_32BIT_ONLY */

Top      Up      ToC       Page 73 
  return shaSuccess;
}

8.2.4.  usha.c

/**************************** usha.c ***************************/
/***************** See RFC 6234 for details. *******************/
/* Copyright (c) 2011 IETF Trust and the persons identified as */
/* authors of the code.  All rights reserved.                  */
/* See sha.h for terms of use and redistribution.              */

/*
 *  Description:
 *     This file implements a unified interface to the SHA algorithms.
 */

#include "sha.h"

/*
 *  USHAReset
 *
 *  Description:
 *      This function will initialize the SHA Context in preparation
 *      for computing a new SHA message digest.
 *
 *  Parameters:
 *      context: [in/out]
 *          The context to reset.
 *      whichSha: [in]
 *          Selects which SHA reset to call
 *
 *  Returns:
 *      sha Error Code.
 *
 */
int USHAReset(USHAContext *context, enum SHAversion whichSha)
{
  if (!context) return shaNull;
  context->whichSha = whichSha;
  switch (whichSha) {
    case SHA1:   return SHA1Reset((SHA1Context*)&context->ctx);
    case SHA224: return SHA224Reset((SHA224Context*)&context->ctx);
    case SHA256: return SHA256Reset((SHA256Context*)&context->ctx);
    case SHA384: return SHA384Reset((SHA384Context*)&context->ctx);
    case SHA512: return SHA512Reset((SHA512Context*)&context->ctx);
    default: return shaBadParam;
  }
}

Top      Up      ToC       Page 74 
/*
 *  USHAInput
 *
 *  Description:
 *      This function accepts an array of octets as the next portion
 *      of the message.
 *
 *  Parameters:
 *      context: [in/out]
 *          The SHA context to update.
 *      message_array: [in]
 *          An array of octets representing the next portion of
 *          the message.
 *      length: [in]
 *          The length of the message in message_array.
 *
 *  Returns:
 *      sha Error Code.
 *
 */
int USHAInput(USHAContext *context,
              const uint8_t *bytes, unsigned int bytecount)
{
  if (!context) return shaNull;
  switch (context->whichSha) {
    case SHA1:
      return SHA1Input((SHA1Context*)&context->ctx, bytes,
                       bytecount);
    case SHA224:
      return SHA224Input((SHA224Context*)&context->ctx, bytes,
          bytecount);
    case SHA256:
      return SHA256Input((SHA256Context*)&context->ctx, bytes,
          bytecount);
    case SHA384:
      return SHA384Input((SHA384Context*)&context->ctx, bytes,
          bytecount);
    case SHA512:
      return SHA512Input((SHA512Context*)&context->ctx, bytes,
          bytecount);
    default: return shaBadParam;
  }
}

Top      Up      ToC       Page 75 
/*
 * USHAFinalBits
 *
 * Description:
 *   This function will add in any final bits of the message.
 *
 * Parameters:
 *   context: [in/out]
 *     The SHA context to update.
 *   message_bits: [in]
 *     The final bits of the message, in the upper portion of the
 *     byte.  (Use 0b###00000 instead of 0b00000### to input the
 *     three bits ###.)
 *   length: [in]
 *     The number of bits in message_bits, between 1 and 7.
 *
 * Returns:
 *   sha Error Code.
 */
int USHAFinalBits(USHAContext *context,
                  uint8_t bits, unsigned int bit_count)
{
  if (!context) return shaNull;
  switch (context->whichSha) {
    case SHA1:
      return SHA1FinalBits((SHA1Context*)&context->ctx, bits,
                           bit_count);
    case SHA224:
      return SHA224FinalBits((SHA224Context*)&context->ctx, bits,
          bit_count);
    case SHA256:
      return SHA256FinalBits((SHA256Context*)&context->ctx, bits,
          bit_count);
    case SHA384:
      return SHA384FinalBits((SHA384Context*)&context->ctx, bits,
          bit_count);
    case SHA512:
      return SHA512FinalBits((SHA512Context*)&context->ctx, bits,
          bit_count);
    default: return shaBadParam;
  }
}

Top      Up      ToC       Page 76 
/*
 * USHAResult
 *
 * Description:
 *   This function will return the message digest of the appropriate
 *   bit size, as returned by USHAHashSizeBits(whichSHA) for the
 *   'whichSHA' value used in the preceeding call to USHAReset,
 *   into the Message_Digest array provided by the caller.
 *
 * Parameters:
 *   context: [in/out]
 *     The context to use to calculate the SHA-1 hash.
 *   Message_Digest: [out]
 *     Where the digest is returned.
 *
 * Returns:
 *   sha Error Code.
 *
 */
int USHAResult(USHAContext *context,
               uint8_t Message_Digest[USHAMaxHashSize])
{
  if (!context) return shaNull;
  switch (context->whichSha) {
    case SHA1:
      return SHA1Result((SHA1Context*)&context->ctx, Message_Digest);
    case SHA224:
      return SHA224Result((SHA224Context*)&context->ctx,
                          Message_Digest);
    case SHA256:
      return SHA256Result((SHA256Context*)&context->ctx,
                          Message_Digest);
    case SHA384:
      return SHA384Result((SHA384Context*)&context->ctx,
                          Message_Digest);
    case SHA512:
      return SHA512Result((SHA512Context*)&context->ctx,
                          Message_Digest);
    default: return shaBadParam;
  }
}

/*
 * USHABlockSize
 *
 * Description:
 *   This function will return the blocksize for the given SHA
 *   algorithm.

Top      Up      ToC       Page 77 
 *
 * Parameters:
 *   whichSha:
 *     which SHA algorithm to query
 *
 * Returns:
 *   block size
 *
 */
int USHABlockSize(enum SHAversion whichSha)
{
  switch (whichSha) {
    case SHA1:   return SHA1_Message_Block_Size;
    case SHA224: return SHA224_Message_Block_Size;
    case SHA256: return SHA256_Message_Block_Size;
    case SHA384: return SHA384_Message_Block_Size;
    default:
    case SHA512: return SHA512_Message_Block_Size;
  }
}

/*
 * USHAHashSize
 *
 * Description:
 *   This function will return the hashsize for the given SHA
 *   algorithm.
 *
 * Parameters:
 *   whichSha:
 *     which SHA algorithm to query
 *
 * Returns:
 *   hash size
 *
 */
int USHAHashSize(enum SHAversion whichSha)
{
  switch (whichSha) {
    case SHA1:   return SHA1HashSize;
    case SHA224: return SHA224HashSize;
    case SHA256: return SHA256HashSize;
    case SHA384: return SHA384HashSize;
    default:
    case SHA512: return SHA512HashSize;
  }
}

Top      Up      ToC       Page 78 
/*
 * USHAHashSizeBits
 *
 * Description:
 *   This function will return the hashsize for the given SHA
 *   algorithm, expressed in bits.
 *
 * Parameters:
 *   whichSha:
 *     which SHA algorithm to query
 *
 * Returns:
 *   hash size in bits
 *
 */
int USHAHashSizeBits(enum SHAversion whichSha)
{
  switch (whichSha) {
    case SHA1:   return SHA1HashSizeBits;
    case SHA224: return SHA224HashSizeBits;
    case SHA256: return SHA256HashSizeBits;
    case SHA384: return SHA384HashSizeBits;
    default:
    case SHA512: return SHA512HashSizeBits;
  }
}

/*
 * USHAHashName
 *
 * Description:
 *   This function will return the name of the given SHA algorithm
 *   as a string.
 *
 * Parameters:
 *   whichSha:
 *     which SHA algorithm to query
 *
 * Returns:
 *   character string with the name in it
 *
 */
const char *USHAHashName(enum SHAversion whichSha)
{
  switch (whichSha) {
    case SHA1:   return "SHA1";
    case SHA224: return "SHA224";
    case SHA256: return "SHA256";

Top      Up      ToC       Page 79 
    case SHA384: return "SHA384";
    default:
    case SHA512: return "SHA512";
  }
}



(page 79 continued on part 4)

Next RFC Part