/*! * \copy *     Copyright (c)  1998, 2009 Paul E. Jones <paulej@packetizer.com> *     All rights reserved. * *     Redistribution and use in source and binary forms, with or without *     modification, are permitted provided that the following conditions *     are met: * *        * Redistributions of source code must retain the above copyright *          notice, this list of conditions and the following disclaimer. * *        * 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. * *     THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS 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 *     COPYRIGHT HOLDER 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. * */ /* *  Description: *      This file implements the Secure Hashing Standard as defined *      in FIPS PUB 180-1 published April 17, 1995. * *      The Secure Hashing Standard, which uses the Secure Hashing *      Algorithm (SHA), produces a 160-bit message digest for a *      given data stream.  In theory, it is highly improbable that *      two messages will produce the same message digest.  Therefore, *      this algorithm 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 was *      written with the expectation that the processor has at least *      a 32-bit machine word size.  If the machine word size is larger, *      the code should still function properly.  One caveat to that *      is that the input functions taking characters and character *      arrays assume that only 8 bits of information are stored in each *      character. * *  Caveats: *      SHA-1 is designed to work with messages less than 2^64 bits *      long. Although SHA-1 allows a message digest to be generated for *      messages of any number of bits less than 2^64, this *      implementation only works with messages with a length that is a *      multiple of the size of an 8-bit character. * */ #include "sha1.h" /* *  Define the circular shift macro */#define SHA1CircularShift(bits,word) \                ((((word) << (bits)) & 0xFFFFFFFF) | \                ((word) >> (32-(bits)))) /* Function prototypes */void SHA1ProcessMessageBlock(SHA1Context *);void SHA1PadMessage(SHA1Context *); /* *  SHA1Reset * *  Description: *      This function will initialize the SHA1Context in preparation *      for computing a new message digest. * *  Parameters: *      context: [in/out] *          The context to reset. * *  Returns: *      Nothing. * *  Comments: * */void SHA1Reset(SHA1Context *context){    context->Length_Low             = 0;    context->Length_High            = 0;    context->Message_Block_Index    = 0;     context->Message_Digest[0]      = 0x67452301;    context->Message_Digest[1]      = 0xEFCDAB89;    context->Message_Digest[2]      = 0x98BADCFE;    context->Message_Digest[3]      = 0x10325476;    context->Message_Digest[4]      = 0xC3D2E1F0;     context->Computed   = 0;    context->Corrupted  = 0;} /* *  SHA1Result * *  Description: *      This function will return the 160-bit message digest into the *      digest array provided as a parameter. * *  Parameters: *      context: [in/out] *          The context to use to calculate the SHA-1 hash. *      digest: [out] *          An array of characters where the digest is written. * *  Returns: *      1 if successful, 0 if it failed. * *  Comments: * */int SHA1Result(SHA1Context *context, unsigned char *digest){    int i;     if (context->Corrupted)    {        return 0;    }     if (!context->Computed)    {        SHA1PadMessage(context);        context->Computed = 1;    }     for (i = 0; i < SHA_DIGEST_LENGTH; i++)        digest[i] = context->Message_Digest[i / 4] >> (8 * (3 - (i % 4)));     return 1;} /* *  SHA1Input * *  Description: *      This function accepts an array of octets as the next portion of *      the message. * *  Parameters: *      context: [in/out] *          The SHA-1 context to update *      message_array: [in] *          An array of characters representing the next portion of the *          message. *      length: [in] *          The length of the message in message_array * *  Returns: *      Nothing. * *  Comments: * */void SHA1Input(     SHA1Context         *context,                    const unsigned char *message_array,                    unsigned            length){    if (!length)    {        return;    }     if (context->Computed || context->Corrupted)    {        context->Corrupted = 1;        return;    }     while(length-- && !context->Corrupted)    {        context->Message_Block[context->Message_Block_Index++] =                                                (*message_array & 0xFF);         context->Length_Low += 8;        /* Force it to 32 bits */        context->Length_Low &= 0xFFFFFFFF;        if (context->Length_Low == 0)        {            context->Length_High++;            /* Force it to 32 bits */            context->Length_High &= 0xFFFFFFFF;            if (context->Length_High == 0)            {                /* Message is too long */                context->Corrupted = 1;            }        }         if (context->Message_Block_Index == 64)        {            SHA1ProcessMessageBlock(context);        }         message_array++;    }} /* *  SHA1ProcessMessageBlock * *  Description: *      This function will process the next 512 bits of the message *      stored in the Message_Block array. * *  Parameters: *      None. * *  Returns: *      Nothing. * *  Comments: *      Many of the variable names in the SHAContext, especially the *      single character names, were used because those were the names *      used in the publication. * * */void SHA1ProcessMessageBlock(SHA1Context *context){    const unsigned K[] =            /* Constants defined in SHA-1   */    {        0x5A827999,        0x6ED9EBA1,        0x8F1BBCDC,        0xCA62C1D6    };    int         t;                  /* Loop counter                 */    unsigned    temp;               /* Temporary word value         */    unsigned    W[80];              /* Word sequence                */    unsigned    A, B, C, D, E;      /* Word buffers                 */     /*     *  Initialize the first 16 words in the array W     */    for(t = 0; t < 16; t++)    {        W[t] = ((unsigned) context->Message_Block[t * 4]) << 24;        W[t] |= ((unsigned) context->Message_Block[t * 4 + 1]) << 16;        W[t] |= ((unsigned) context->Message_Block[t * 4 + 2]) << 8;        W[t] |= ((unsigned) context->Message_Block[t * 4 + 3]);    }     for(t = 16; t < 80; t++)    {       W[t] = SHA1CircularShift(1,W[t-3] ^ W[t-8] ^ W[t-14] ^ W[t-16]);    }     A = context->Message_Digest[0];    B = context->Message_Digest[1];    C = context->Message_Digest[2];    D = context->Message_Digest[3];    E = context->Message_Digest[4];     for(t = 0; t < 20; t++)    {        temp =  SHA1CircularShift(5,A) +                ((B & C) | ((~B) & D)) + E + W[t] + K[0];        temp &= 0xFFFFFFFF;        E = D;        D = C;        C = SHA1CircularShift(30,B);        B = A;        A = temp;    }     for(t = 20; t < 40; t++)    {        temp = SHA1CircularShift(5,A) + (B ^ C ^ D) + E + W[t] + K[1];        temp &= 0xFFFFFFFF;        E = D;        D = C;        C = SHA1CircularShift(30,B);        B = A;        A = temp;    }     for(t = 40; t < 60; t++)    {        temp = SHA1CircularShift(5,A) +               ((B & C) | (B & D) | (C & D)) + E + W[t] + K[2];        temp &= 0xFFFFFFFF;        E = D;        D = C;        C = SHA1CircularShift(30,B);        B = A;        A = temp;    }     for(t = 60; t < 80; t++)    {        temp = SHA1CircularShift(5,A) + (B ^ C ^ D) + E + W[t] + K[3];        temp &= 0xFFFFFFFF;        E = D;        D = C;        C = SHA1CircularShift(30,B);        B = A;        A = temp;    }     context->Message_Digest[0] =                        (context->Message_Digest[0] + A) & 0xFFFFFFFF;    context->Message_Digest[1] =                        (context->Message_Digest[1] + B) & 0xFFFFFFFF;    context->Message_Digest[2] =                        (context->Message_Digest[2] + C) & 0xFFFFFFFF;    context->Message_Digest[3] =                        (context->Message_Digest[3] + D) & 0xFFFFFFFF;    context->Message_Digest[4] =                        (context->Message_Digest[4] + E) & 0xFFFFFFFF;     context->Message_Block_Index = 0;} /* *  SHA1PadMessage * *  Description: *      According to the standard, the message must be padded to an even *      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 function will pad the message *      according to those rules by filling the Message_Block array *      accordingly.  It will also call SHA1ProcessMessageBlock() *      appropriately.  When it returns, it can be assumed that the *      message digest has been computed. * *  Parameters: *      context: [in/out] *          The context to pad * *  Returns: *      Nothing. * *  Comments: * */void SHA1PadMessage(SHA1Context *context){    /*     *  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 > 55)    {        context->Message_Block[context->Message_Block_Index++] = 0x80;        while(context->Message_Block_Index < 64)        {            context->Message_Block[context->Message_Block_Index++] = 0;        }         SHA1ProcessMessageBlock(context);         while(context->Message_Block_Index < 56)        {            context->Message_Block[context->Message_Block_Index++] = 0;        }    }    else    {        context->Message_Block[context->Message_Block_Index++] = 0x80;        while(context->Message_Block_Index < 56)        {            context->Message_Block[context->Message_Block_Index++] = 0;        }    }     /*     *  Store the message length as the last 8 octets     */    context->Message_Block[56] = (context->Length_High >> 24) & 0xFF;    context->Message_Block[57] = (context->Length_High >> 16) & 0xFF;    context->Message_Block[58] = (context->Length_High >> 8) & 0xFF;    context->Message_Block[59] = (context->Length_High) & 0xFF;    context->Message_Block[60] = (context->Length_Low >> 24) & 0xFF;    context->Message_Block[61] = (context->Length_Low >> 16) & 0xFF;    context->Message_Block[62] = (context->Length_Low >> 8) & 0xFF;    context->Message_Block[63] = (context->Length_Low) & 0xFF;     SHA1ProcessMessageBlock(context);}