Artifact a03e9d2d38e3a88ec774a125d422b68d6c4469b1:
- File
sha1.c
— part of check-in
[02f5cea2da]
at
2011-09-08 01:47:17
on branch trunk
— CACKey 0.6.2
Updated to include sha1.c, md5.c, and asn1-x509.c in the cackey.c translation unit so that these symbols never get exported and conflict with existing programs
Updated to try harder to remove and weaken symbols from shared object (user: rkeene, size: 10311) [annotate] [blame] [check-ins using]
/* * 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. * */ #include "sha1.h" /* * Define the SHA1 circular left shift macro */ #define SHA1CircularShift(bits,word) \ (((word) << (bits)) | ((word) >> (32-(bits)))) /* Local Function Prototyptes */ static void SHA1PadMessage(SHA1Context *); static 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. * */ static 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. * */ static 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. * */ static 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. * * */ static 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. * */ static 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); }