--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/Resources/sha1/sha1.cpp	Fri Nov 09 10:42:00 2012 +0100
@@ -0,0 +1,589 @@
+/*
+ *  sha1.cpp
+ *
+ *  Copyright (C) 1998, 2009
+ *  Paul E. Jones <paulej@packetizer.com>
+ *  All Rights Reserved.
+ *
+ *****************************************************************************
+ *  $Id: sha1.cpp 12 2009-06-22 19:34:25Z paulej $
+ *****************************************************************************
+ *
+ *  Description:
+ *      This class 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 8
+ *      bits.
+ *
+ */
+
+
+#include "sha1.h"
+
+/*  
+ *  SHA1
+ *
+ *  Description:
+ *      This is the constructor for the sha1 class.
+ *
+ *  Parameters:
+ *      None.
+ *
+ *  Returns:
+ *      Nothing.
+ *
+ *  Comments:
+ *
+ */
+SHA1::SHA1()
+{
+    Reset();
+}
+
+/*  
+ *  ~SHA1
+ *
+ *  Description:
+ *      This is the destructor for the sha1 class
+ *
+ *  Parameters:
+ *      None.
+ *
+ *  Returns:
+ *      Nothing.
+ *
+ *  Comments:
+ *
+ */
+SHA1::~SHA1()
+{
+    // The destructor does nothing
+}
+
+/*  
+ *  Reset
+ *
+ *  Description:
+ *      This function will initialize the sha1 class member variables
+ *      in preparation for computing a new message digest.
+ *
+ *  Parameters:
+ *      None.
+ *
+ *  Returns:
+ *      Nothing.
+ *
+ *  Comments:
+ *
+ */
+void SHA1::Reset()
+{
+    Length_Low          = 0;
+    Length_High         = 0;
+    Message_Block_Index = 0;
+
+    H[0]        = 0x67452301;
+    H[1]        = 0xEFCDAB89;
+    H[2]        = 0x98BADCFE;
+    H[3]        = 0x10325476;
+    H[4]        = 0xC3D2E1F0;
+
+    Computed    = false;
+    Corrupted   = false;
+}
+
+/*  
+ *  Result
+ *
+ *  Description:
+ *      This function will return the 160-bit message digest into the
+ *      array provided.
+ *
+ *  Parameters:
+ *      message_digest_array: [out]
+ *          This is an array of five unsigned integers which will be filled
+ *          with the message digest that has been computed.
+ *
+ *  Returns:
+ *      True if successful, false if it failed.
+ *
+ *  Comments:
+ *
+ */
+bool SHA1::Result(unsigned *message_digest_array)
+{
+    int i;                                  // Counter
+
+    if (Corrupted)
+    {
+        return false;
+    }
+
+    if (!Computed)
+    {
+        PadMessage();
+        Computed = true;
+    }
+
+    for(i = 0; i < 5; i++)
+    {
+        message_digest_array[i] = H[i];
+    }
+
+    return true;
+}
+
+/*  
+ *  Input
+ *
+ *  Description:
+ *      This function accepts an array of octets as the next portion of
+ *      the message.
+ *
+ *  Parameters:
+ *      message_array: [in]
+ *          An array of characters representing the next portion of the
+ *          message.
+ *
+ *  Returns:
+ *      Nothing.
+ *
+ *  Comments:
+ *
+ */
+void SHA1::Input(   const unsigned char *message_array,
+                    unsigned            length)
+{
+    if (!length)
+    {
+        return;
+    }
+
+    if (Computed || Corrupted)
+    {
+        Corrupted = true;
+        return;
+    }
+
+    while(length-- && !Corrupted)
+    {
+        Message_Block[Message_Block_Index++] = (*message_array & 0xFF);
+
+        Length_Low += 8;
+        Length_Low &= 0xFFFFFFFF;               // Force it to 32 bits
+        if (Length_Low == 0)
+        {
+            Length_High++;
+            Length_High &= 0xFFFFFFFF;          // Force it to 32 bits
+            if (Length_High == 0)
+            {
+                Corrupted = true;               // Message is too long
+            }
+        }
+
+        if (Message_Block_Index == 64)
+        {
+            ProcessMessageBlock();
+        }
+
+        message_array++;
+    }
+}
+
+/*  
+ *  Input
+ *
+ *  Description:
+ *      This function accepts an array of octets as the next portion of
+ *      the message.
+ *
+ *  Parameters:
+ *      message_array: [in]
+ *          An array of characters representing the next portion of the
+ *          message.
+ *      length: [in]
+ *          The length of the message_array
+ *
+ *  Returns:
+ *      Nothing.
+ *
+ *  Comments:
+ *
+ */
+void SHA1::Input(   const char  *message_array,
+                    unsigned    length)
+{
+    Input((unsigned char *) message_array, length);
+}
+
+/*  
+ *  Input
+ *
+ *  Description:
+ *      This function accepts a single octets as the next message element.
+ *
+ *  Parameters:
+ *      message_element: [in]
+ *          The next octet in the message.
+ *
+ *  Returns:
+ *      Nothing.
+ *
+ *  Comments:
+ *
+ */
+void SHA1::Input(unsigned char message_element)
+{
+    Input(&message_element, 1);
+}
+
+/*  
+ *  Input
+ *
+ *  Description:
+ *      This function accepts a single octet as the next message element.
+ *
+ *  Parameters:
+ *      message_element: [in]
+ *          The next octet in the message.
+ *
+ *  Returns:
+ *      Nothing.
+ *
+ *  Comments:
+ *
+ */
+void SHA1::Input(char message_element)
+{
+    Input((unsigned char *) &message_element, 1);
+}
+
+/*  
+ *  operator<<
+ *
+ *  Description:
+ *      This operator makes it convenient to provide character strings to
+ *      the SHA1 object for processing.
+ *
+ *  Parameters:
+ *      message_array: [in]
+ *          The character array to take as input.
+ *
+ *  Returns:
+ *      A reference to the SHA1 object.
+ *
+ *  Comments:
+ *      Each character is assumed to hold 8 bits of information.
+ *
+ */
+SHA1& SHA1::operator<<(const char *message_array)
+{
+    const char *p = message_array;
+
+    while(*p)
+    {
+        Input(*p);
+        p++;
+    }
+
+    return *this;
+}
+
+/*  
+ *  operator<<
+ *
+ *  Description:
+ *      This operator makes it convenient to provide character strings to
+ *      the SHA1 object for processing.
+ *
+ *  Parameters:
+ *      message_array: [in]
+ *          The character array to take as input.
+ *
+ *  Returns:
+ *      A reference to the SHA1 object.
+ *
+ *  Comments:
+ *      Each character is assumed to hold 8 bits of information.
+ *
+ */
+SHA1& SHA1::operator<<(const unsigned char *message_array)
+{
+    const unsigned char *p = message_array;
+
+    while(*p)
+    {
+        Input(*p);
+        p++;
+    }
+
+    return *this;
+}
+
+/*  
+ *  operator<<
+ *
+ *  Description:
+ *      This function provides the next octet in the message.
+ *
+ *  Parameters:
+ *      message_element: [in]
+ *          The next octet in the message
+ *
+ *  Returns:
+ *      A reference to the SHA1 object.
+ *
+ *  Comments:
+ *      The character is assumed to hold 8 bits of information.
+ *
+ */
+SHA1& SHA1::operator<<(const char message_element)
+{
+    Input((unsigned char *) &message_element, 1);
+
+    return *this;
+}
+
+/*  
+ *  operator<<
+ *
+ *  Description:
+ *      This function provides the next octet in the message.
+ *
+ *  Parameters:
+ *      message_element: [in]
+ *          The next octet in the message
+ *
+ *  Returns:
+ *      A reference to the SHA1 object.
+ *
+ *  Comments:
+ *      The character is assumed to hold 8 bits of information.
+ *
+ */
+SHA1& SHA1::operator<<(const unsigned char message_element)
+{
+    Input(&message_element, 1);
+
+    return *this;
+}
+
+/*  
+ *  ProcessMessageBlock
+ *
+ *  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 function, especially the single
+ *      character names, were used because those were the names used
+ *      in the publication.
+ *
+ */
+void SHA1::ProcessMessageBlock()
+{
+    const unsigned K[] =    {               // Constants defined for 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) Message_Block[t * 4]) << 24;
+        W[t] |= ((unsigned) Message_Block[t * 4 + 1]) << 16;
+        W[t] |= ((unsigned) Message_Block[t * 4 + 2]) << 8;
+        W[t] |= ((unsigned) Message_Block[t * 4 + 3]);
+    }
+
+    for(t = 16; t < 80; t++)
+    {
+       W[t] = CircularShift(1,W[t-3] ^ W[t-8] ^ W[t-14] ^ W[t-16]);
+    }
+
+    A = H[0];
+    B = H[1];
+    C = H[2];
+    D = H[3];
+    E = H[4];
+
+    for(t = 0; t < 20; t++)
+    {
+        temp = CircularShift(5,A) + ((B & C) | ((~B) & D)) + E + W[t] + K[0];
+        temp &= 0xFFFFFFFF;
+        E = D;
+        D = C;
+        C = CircularShift(30,B);
+        B = A;
+        A = temp;
+    }
+
+    for(t = 20; t < 40; t++)
+    {
+        temp = CircularShift(5,A) + (B ^ C ^ D) + E + W[t] + K[1];
+        temp &= 0xFFFFFFFF;
+        E = D;
+        D = C;
+        C = CircularShift(30,B);
+        B = A;
+        A = temp;
+    }
+
+    for(t = 40; t < 60; t++)
+    {
+        temp = CircularShift(5,A) +
+               ((B & C) | (B & D) | (C & D)) + E + W[t] + K[2];
+        temp &= 0xFFFFFFFF;
+        E = D;
+        D = C;
+        C = CircularShift(30,B);
+        B = A;
+        A = temp;
+    }
+
+    for(t = 60; t < 80; t++)
+    {
+        temp = CircularShift(5,A) + (B ^ C ^ D) + E + W[t] + K[3];
+        temp &= 0xFFFFFFFF;
+        E = D;
+        D = C;
+        C = CircularShift(30,B);
+        B = A;
+        A = temp;
+    }
+
+    H[0] = (H[0] + A) & 0xFFFFFFFF;
+    H[1] = (H[1] + B) & 0xFFFFFFFF;
+    H[2] = (H[2] + C) & 0xFFFFFFFF;
+    H[3] = (H[3] + D) & 0xFFFFFFFF;
+    H[4] = (H[4] + E) & 0xFFFFFFFF;
+
+    Message_Block_Index = 0;
+}
+
+/*  
+ *  PadMessage
+ *
+ *  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 ProcessMessageBlock() appropriately.  When it returns, it
+ *      can be assumed that the message digest has been computed.
+ *
+ *  Parameters:
+ *      None.
+ *
+ *  Returns:
+ *      Nothing.
+ *
+ *  Comments:
+ *
+ */
+void SHA1::PadMessage()
+{
+    /*
+     *  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 (Message_Block_Index > 55)
+    {
+        Message_Block[Message_Block_Index++] = 0x80;
+        while(Message_Block_Index < 64)
+        {
+            Message_Block[Message_Block_Index++] = 0;
+        }
+
+        ProcessMessageBlock();
+
+        while(Message_Block_Index < 56)
+        {
+            Message_Block[Message_Block_Index++] = 0;
+        }
+    }
+    else
+    {
+        Message_Block[Message_Block_Index++] = 0x80;
+        while(Message_Block_Index < 56)
+        {
+            Message_Block[Message_Block_Index++] = 0;
+        }
+
+    }
+
+    /*
+     *  Store the message length as the last 8 octets
+     */
+    Message_Block[56] = (Length_High >> 24) & 0xFF;
+    Message_Block[57] = (Length_High >> 16) & 0xFF;
+    Message_Block[58] = (Length_High >> 8) & 0xFF;
+    Message_Block[59] = (Length_High) & 0xFF;
+    Message_Block[60] = (Length_Low >> 24) & 0xFF;
+    Message_Block[61] = (Length_Low >> 16) & 0xFF;
+    Message_Block[62] = (Length_Low >> 8) & 0xFF;
+    Message_Block[63] = (Length_Low) & 0xFF;
+
+    ProcessMessageBlock();
+}
+
+
+/*  
+ *  CircularShift
+ *
+ *  Description:
+ *      This member function will perform a circular shifting operation.
+ *
+ *  Parameters:
+ *      bits: [in]
+ *          The number of bits to shift (1-31)
+ *      word: [in]
+ *          The value to shift (assumes a 32-bit integer)
+ *
+ *  Returns:
+ *      The shifted value.
+ *
+ *  Comments:
+ *
+ */
+unsigned SHA1::CircularShift(int bits, unsigned word)
+{
+    return ((word << bits) & 0xFFFFFFFF) | ((word & 0xFFFFFFFF) >> (32-bits));
+}