/* * tsf_sha1.c * * Copyright (C) 1998, 2009 * Paul E. Jones * All Rights Reserved * * Freeware Public License (FPL) * * This software is licensed as "freeware." Permission to distribute * this software in source and binary forms, including incorporation * into other products, is hereby granted without a fee. THIS SOFTWARE * IS PROVIDED 'AS IS' AND WITHOUT ANY EXPRESSED OR IMPLIED WARRANTIES, * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY * AND FITNESS FOR A PARTICULAR PURPOSE. THE AUTHOR SHALL NOT BE HELD * LIABLE FOR ANY DAMAGES RESULTING FROM THE USE OF THIS SOFTWARE, EITHER * DIRECTLY OR INDIRECTLY, INCLUDING, BUT NOT LIMITED TO, LOSS OF DATA * OR DATA BEING RENDERED INACCURATE. * ***************************************************************************** * $Id: sha1.c 12 2009-06-22 19:34:25Z paulej $ ***************************************************************************** * * 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 "tsf_sha1.h" /* * Define the circular shift macro */ static TSF_inline uint32_t SHA1CircularShift(uint32_t bits, uint32_t word) { return ((((word) << (bits)) & 0xFFFFFFFF) | ((word) >> (32-(bits)))); } /* Function prototypes */ static void SHA1ProcessMessageBlock(tsf_SHA1Context *); static void SHA1PadMessage(tsf_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 tsf_SHA1Reset(tsf_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 * Message_Digest array within the SHA1Context provided * * Parameters: * context: [in/out] * The context to use to calculate the SHA-1 hash. * * Returns: * 1 if successful, 0 if it failed. * * Comments: * */ int32_t tsf_SHA1Result(tsf_SHA1Context *context) { if (context->Corrupted) { return 0; } if (!context->Computed) { SHA1PadMessage(context); context->Computed = 1; } 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 tsf_SHA1Input( tsf_SHA1Context *context, const uint8_t *message_array, uint32_t 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. * * */ static void SHA1ProcessMessageBlock(tsf_SHA1Context *context) { const unsigned K[] = /* Constants defined in SHA-1 */ { 0x5A827999, 0x6ED9EBA1, 0x8F1BBCDC, 0xCA62C1D6 }; int32_t 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] = ((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: * */ static void SHA1PadMessage(tsf_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); }