sha1.h

SHA家族加密算法实现方式, C语言版本

//
//		  f(t;B,C,D) = B XOR C XOR D                        (60 <= t <= 79).
//
//	   A sequence of constant words K(0), K(1), ... , K(79) is used in the
//	   SHA-1.  In hex these are given by
//
//		  K(t) = 5A827999         ( 0 <= t <= 19)
//
//		  K(t) = 6ED9EBA1         (20 <= t <= 39)
//
//		  K(t) = 8F1BBCDC         (40 <= t <= 59)
//
//		  K(t) = CA62C1D6         (60 <= t <= 79).
//
//	6. Computing the Message Digest
//
//	   The methods given in 6.1 and 6.2 below yield the same message digest.
//	   Although using method 2 saves sixty-four 32-bit words of storage, it
//	   is likely to lengthen execution time due to the increased complexity
//	   of the address computations for the { W[t] } in step (c).  There are
//	   other computation methods which give identical results.
//
//	6.1 Method 1
//
//	   The message digest is computed using the message padded as described
//	   in section 4.  The computation is described using two buffers, each
//	   consisting of five 32-bit words, and a sequence of eighty 32-bit
//	   words.  The words of the first 5-word buffer are labeled A,B,C,D,E.
//	   The words of the second 5-word buffer are labeled H0, H1, H2, H3, H4.
//	   The words of the 80-word sequence are labeled W(0), W(1),..., W(79).
//	   A single word buffer TEMP is also employed.
//
//	   To generate the message digest, the 16-word blocks M(1), M(2),...,
//	   M(n) defined in section 4 are processed in order.  The processing of
//	   each M(i) involves 80 steps.
//
//
//
//
//	Eastlake & Jones             Informational                      [Page 6]
//	
//	RFC 3174           US Secure Hash Algorithm 1 (SHA1)      September 2001
//
//
//	   Before processing any blocks, the H's are initialized as follows: in
//	   hex,
//
//		  H0 = 67452301
//
//		  H1 = EFCDAB89
//
//		  H2 = 98BADCFE
//
//		  H3 = 10325476
//
//		  H4 = C3D2E1F0.
//
//	   Now M(1), M(2), ... , M(n) are processed.  To process M(i), we
//	   proceed as follows:
//
//		  a. Divide M(i) into 16 words W(0), W(1), ... , W(15), where W(0)
//			 is the left-most word.
//
//		  b. For t = 16 to 79 let
//
//			 W(t) = S^1(W(t-3) XOR W(t-8) XOR W(t-14) XOR W(t-16)).
//
//		  c. Let A = H0, B = H1, C = H2, D = H3, E = H4.
//
//		  d. For t = 0 to 79 do
//
//			 TEMP = S^5(A) + f(t;B,C,D) + E + W(t) + K(t);
//
//			 E = D;  D = C;  C = S^30(B);  B = A; A = TEMP;
//
//		  e. Let H0 = H0 + A, H1 = H1 + B, H2 = H2 + C, H3 = H3 + D, H4 = H4
//			 + E.
//
//	   After processing M(n), the message digest is the 160-bit string
//	   represented by the 5 words
//
//			 H0 H1 H2 H3 H4.
//
//	6.2 Method 2
//
//	   The method above assumes that the sequence W(0), ... , W(79) is
//	   implemented as an array of eighty 32-bit words.  This is efficient
//	   from the standpoint of minimization of execution time, since the
//	   addresses of W(t-3), ...  ,W(t-16) in step (b) are easily computed.
//	   If space is at a premium, an alternative is to regard { W(t) } as a
//
//
//
//
//
//	Eastlake & Jones             Informational                      [Page 7]
//	
//	RFC 3174           US Secure Hash Algorithm 1 (SHA1)      September 2001
//
//
//	   circular queue, which may be implemented using an array of sixteen
//	   32-bit words W[0], ... W[15].  In this case, in hex let
//
//	   MASK = 0000000F.  Then processing of M(i) is as follows:
//
//		  a. Divide M(i) into 16 words W[0], ... , W[15], where W[0] is the
//			 left-most word.
//
//		  b. Let A = H0, B = H1, C = H2, D = H3, E = H4.
//
//		  c. For t = 0 to 79 do
//
//			 s = t AND MASK;
//
//			 if (t >= 16) W[s] = S^1(W[(s + 13) AND MASK] XOR W[(s + 8) AND
//			 MASK] XOR W[(s + 2) AND MASK] XOR W[s]);
//
//			 TEMP = S^5(A) + f(t;B,C,D) + E + W[s] + K(t);
//
//			 E = D; D = C; C = S^30(B); B = A; A = TEMP;
//
//		  d. Let H0 = H0 + A, H1 = H1 + B, H2 = H2 + C, H3 = H3 + D, H4 = H4
//			 + E.
//
//	7. C Code
//
//	   Below is a demonstration implementation of SHA-1 in C.  Section 7.1
//	   contains the header file, 7.2 the C code, and 7.3 a test driver.
//
//	7.1 .h file
//
//	/*
//	 *  sha1.h
//	 *
//	 *  Description:
//	 *      This is the header file for code which implements the Secure
//	 *      Hashing Algorithm 1 as defined in FIPS PUB 180-1 published
//	 *      April 17, 1995.
//	 *
//	 *      Many of the variable names in this code, especially the
//	 *      single character names, were used because those were the names
//	 *      used in the publication.
//	 *
//	 *      Please read the file sha1.c for more information.
//	 *
//	 */
//
//
//
//
//
//	Eastlake & Jones             Informational                      [Page 8]
//	
//	RFC 3174           US Secure Hash Algorithm 1 (SHA1)      September 2001
//
//
//	#ifndef _SHA1_H_
//	#define _SHA1_H_
//
//	#include <stdint.h>
//	/*
//	 * If you do not have the ISO standard stdint.h header file, then you
//	 * must typdef the following:
//	 *    name              meaning
//	 *  uint32_t         unsigned 32 bit integer
//	 *  uint8_t          unsigned 8 bit integer (i.e., unsigned char)
//	 *  int_least16_t    integer of >= 16 bits
//	 *
//	 */
//
//	#ifndef _SHA_enum_
//	#define _SHA_enum_
//	enum
//	{
//		shaSuccess = 0,
//		shaNull,            /* Null pointer parameter */
//		shaInputTooLong,    /* input data too long */
//		shaStateError       /* called Input after Result */
//	};
//	#endif
//	#define SHA1HashSize 20
//
//	/*
//	 *  This structure will hold context information for the SHA-1
//	 *  hashing operation
//	 */
//	typedef struct SHA1Context
//	{
//		uint32_t Intermediate_Hash[SHA1HashSize/4]; /* Message Digest  */
//
//		uint32_t Length_Low;            /* Message length in bits      */
//		uint32_t Length_High;           /* Message length in bits      */
//
//								   /* Index into message block array   */
//		int_least16_t Message_Block_Index;
//		uint8_t Message_Block[64];      /* 512-bit message blocks      */
//
//		int Computed;               /* Is the digest computed?         */
//		int Corrupted;             /* Is the message digest corrupted? */
//	} SHA1Context;
//
//	/*
//	 *  Function Prototypes
//	 */
//
//
//
//	Eastlake & Jones             Informational                      [Page 9]
//	
//	RFC 3174           US Secure Hash Algorithm 1 (SHA1)      September 2001
//
//
//	int SHA1Reset(  SHA1Context *);
//	int SHA1Input(  SHA1Context *,
//					const uint8_t *,
//					unsigned int);
//	int SHA1Result( SHA1Context *,
//					uint8_t Message_Digest[SHA1HashSize]);
//
//	#endif
//
//	7.2 .c file
//
//	/*
//	 *  sha1.c
//	 *
//	 *  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.
//	 *
//	 */
//
//
//
//
//
//
//
//
//
//
//	Eastlake & Jones             Informational                     [Page 10]
//	
//	RFC 3174           US Secure Hash Algorithm 1 (SHA1)      September 2001
//
//
//	#include "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;
//
//
//
//
//
//	Eastlake & Jones             Informational                     [Page 11]
//	
//	RFC 3174           US Secure Hash Algorithm 1 (SHA1)      September 2001
//
//
//		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;
//
//
//
//	Eastlake & Jones             Informational                     [Page 12]
//	
//	RFC 3174           US Secure Hash Algorithm 1 (SHA1)      September 2001
//
//
//		}
//
//		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;
//
//
//
//	Eastlake & Jones             Informational                     [Page 13]
//	
//	RFC 3174           US Secure Hash Algorithm 1 (SHA1)      September 2001
//
//
//			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;
//	}