add support for Zaptel transcoders

[asterisk-bristuff.git] / sha1.c

/*
 *
 * Based on the RFC 3174
 * 
 * Full Copyright Statement
 *
 *  Copyright (C) The Internet Society (2001).  All Rights Reserved.
 *
 *  This document and translations of it may be copied and furnished to
 *  others, and derivative works that comment on or otherwise explain it
 *  or assist in its implementation may be prepared, copied, published
 *  and distributed, in whole or in part, without restriction of any
 *  kind, provided that the above copyright notice and this paragraph are
 *  included on all such copies and derivative works.  However, this
 *  document itself may not be modified in any way, such as by removing
 *  the copyright notice or references to the Internet Society or other
 *  Internet organizations, except as needed for the purpose of
 *  developing Internet standards in which case the procedures for
 *  copyrights defined in the Internet Standards process must be
 *  followed, or as required to translate it into languages other than
 *  English.
 *
 *  The limited permissions granted above are perpetual and will not be
 *  revoked by the Internet Society or its successors or assigns.

 *  This document and the information contained herein is provided on an
 *  "AS IS" basis and THE INTERNET SOCIETY AND THE INTERNET ENGINEERING
 *  TASK FORCE DISCLAIMS ALL WARRANTIES, EXPRESS OR IMPLIED, INCLUDING
 *  BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF THE INFORMATION
 *  HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED WARRANTIES OF
 *  MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.
 *
 *
 * 
 *  Description:
 *        This file implements the Secure Hashing Algorithm 1 as
 *        defined in FIPS PUB 180-1 published April 17, 1995.
 *
 *        The SHA-1, produces a 160-bit message digest 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-1 is defined in terms of 32-bit "words".  This code
 *        uses <stdint.h> (included via "sha1.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.  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 "asterisk/sha1.h"

/*
 *  Define the SHA1 circular left shift macro
 */
#define SHA1CircularShift(bits,word) \
                         (((word) << (bits)) | ((word) >> (32-(bits))))

/* Local Function Prototyptes */
void SHA1PadMessage(SHA1Context *);
void SHA1ProcessMessageBlock(SHA1Context *);

/*
 *  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_Low               = 0;
        context->Length_High             = 0;
        context->Message_Block_Index     = 0;

        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  = 0;

        return shaSuccess;
}

/*
 *  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 0th element,
 *                   the last octet of hash in the 19th element.
 *
 *  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 SHA1Result( SHA1Context *context,
                         uint8_t Message_Digest[SHA1HashSize])
{
        int i;

        if (!context || !Message_Digest)
        {
                 return shaNull;
        }

        if (context->Corrupted)
        {
                 return context->Corrupted;
        }

        if (!context->Computed)
        {
                 SHA1PadMessage(context);
                 for(i=0; i<64; ++i)
                 {
                     /* message may be sensitive, clear it out */
                     context->Message_Block[i] = 0;
                 }
                 context->Length_Low = 0;    /* and clear length */
                 context->Length_High = 0;
                 context->Computed = 1;

        }

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

        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 characters representing the next portion of
 *                 the message.
 *        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 (!length)
        {
                 return shaSuccess;
        }

        if (!context || !message_array)
        {
                 return shaNull;
        }

        if (context->Computed)
        {
                 context->Corrupted = shaStateError;
                 return shaStateError;
        }

        if (context->Corrupted)
        {
                  return context->Corrupted;
        }
        while(length-- && !context->Corrupted)
        {
        context->Message_Block[context->Message_Block_Index++] =
                             (*message_array & 0xFF);

        context->Length_Low += 8;
        if (context->Length_Low == 0)
        {
                 context->Length_High++;
                 if (context->Length_High == 0)
                 {
                     /* Message is too long */
                     context->Corrupted = 1;
                 }
        }

        if (context->Message_Block_Index == 64)
        {
                 SHA1ProcessMessageBlock(context);
        }

        message_array++;
        }

        return shaSuccess;
}

/*
 *  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 this code, especially the
 *        single character names, were used because those were the
 *        names used in the publication.
 *
 *
 */
void SHA1ProcessMessageBlock(SHA1Context *context)
{
        const uint32_t K[] =     {       /* Constants defined in SHA-1   */
                                     0x5A827999,
                                     0x6ED9EBA1,
                                     0x8F1BBCDC,
                                     0xCA62C1D6
                                     };
        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] = context->Message_Block[t * 4] << 24;
                 W[t] |= context->Message_Block[t * 4 + 1] << 16;
                 W[t] |= context->Message_Block[t * 4 + 2] << 8;
                 W[t] |= 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->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 =  SHA1CircularShift(5,A) +
                         ((B & C) | ((~B) & D)) + E + W[t] + K[0];
                 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];
                 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];
                 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];
                 E = D;
                 D = C;
                 C = SHA1CircularShift(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;
}


/*
 *  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 the ProcessMessageBlock function
 *        provided appropriately.  When it returns, it can be assumed that
 *        the message digest has been computed.
 *
 *  Parameters:
 *        context: [in/out]
 *                 The context to pad
 *        ProcessMessageBlock: [in]
 *                 The appropriate SHA*ProcessMessageBlock function
 *  Returns:
 *        Nothing.
 *
 */

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;
        context->Message_Block[57] = context->Length_High >> 16;
        context->Message_Block[58] = context->Length_High >> 8;
        context->Message_Block[59] = context->Length_High;
        context->Message_Block[60] = context->Length_Low >> 24;
        context->Message_Block[61] = context->Length_Low >> 16;
        context->Message_Block[62] = context->Length_Low >> 8;
        context->Message_Block[63] = context->Length_Low;

        SHA1ProcessMessageBlock(context);
}