+++ /dev/null
-/*
- * 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 */
-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);
-}
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