@@ -1,47 +1,68 @@ +/**************************** sha1.c ***************************/ +/***************** See RFC 6234 for details. *******************/ +/* Copyright (c) 2011 IETF Trust and the persons identified as */ +/* authors of the code. All rights reserved. */ +/* See sha.h for terms of use and redistribution. */ + /* - * 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 + * This file implements the Secure Hash Algorithm SHA-1 + * as defined in the U.S. National Institute of Standards + * and Technology Federal Information Processing Standards + * Publication (FIPS PUB) 180-3 published in October 2008 + * and formerly defined in its predecessors, FIPS PUB 180-1 + * and FIP PUB 180-2. + * + * A combined document showing all algorithms is available at + * http://csrc.nist.gov/publications/fips/ + * fips180-3/fips180-3_final.pdf + * + * The SHA-1 algorithm produces a 160-bit message digest for a + * given data stream that 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 (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 + * uses (included via "sha.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. - * + * long. This implementation uses SHA1Input() to hash the bits + * that are a multiple of the size of an 8-bit octet, and then + * optionally uses SHA1FinalBits() to hash the final few bits of + * the input. */ -#include "sha1.h" +#include "sha.h" +#include "sha-private.h" /* * Define the SHA1 circular left shift macro */ -#define SHA1CircularShift(bits,word) \ +#define SHA1_ROTL(bits,word) \ (((word) << (bits)) | ((word) >> (32-(bits)))) -/* Local Function Prototyptes */ -static void SHA1PadMessage(SHA1Context *); -static void SHA1ProcessMessageBlock(SHA1Context *); +/* + * Add "length" to the length. + * Set Corrupted when overflow has occurred. + */ +static uint32_t addTemp; +#define SHA1AddLength(context, length) \ + (addTemp = (context)->Length_Low, \ + (context)->Corrupted = \ + (((context)->Length_Low += (length)) < addTemp) && \ + (++(context)->Length_High == 0) ? shaInputTooLong \ + : (context)->Corrupted ) + +/* Local Function Prototypes */ +static void SHA1ProcessMessageBlock(SHA1Context *context); +static void SHA1Finalize(SHA1Context *context, uint8_t Pad_Byte); +static void SHA1PadMessage(SHA1Context *context, uint8_t Pad_Byte); /* * SHA1Reset * * Description: @@ -54,87 +75,28 @@ * * 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; +int SHA1Reset(SHA1Context *context) +{ + if (!context) return shaNull; + + context->Length_High = context->Length_Low = 0; + context->Message_Block_Index = 0; + + /* Initial Hash Values: FIPS 180-3 section 5.3.1 */ + 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 = shaSuccess; + + return shaSuccess; } /* * SHA1Input * @@ -142,244 +104,311 @@ * 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 SHA context to update. + * message_array[ ]: [in] + * An array of octets representing the next portion of * the message. * length: [in] - * The length of the message in message_array + * 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); - } +int SHA1Input(SHA1Context *context, + const uint8_t *message_array, unsigned length) +{ + if (!context) return shaNull; + if (!length) return shaSuccess; + if (!message_array) return shaNull; + if (context->Computed) return context->Corrupted = shaStateError; + if (context->Corrupted) return context->Corrupted; + + while (length--) { + context->Message_Block[context->Message_Block_Index++] = + *message_array; + + if ((SHA1AddLength(context, 8) == shaSuccess) && + (context->Message_Block_Index == SHA1_Message_Block_Size)) + SHA1ProcessMessageBlock(context); message_array++; - } + } + + return context->Corrupted; +} + +/* + * SHA1FinalBits + * + * Description: + * This function will add in any final bits of the message. + * + * Parameters: + * context: [in/out] + * The SHA context to update. + * message_bits: [in] + * The final bits of the message, in the upper portion of the + * byte. (Use 0b###00000 instead of 0b00000### to input the + * three bits ###.) + * length: [in] + * The number of bits in message_bits, between 1 and 7. + * + * Returns: + * sha Error Code. + */ +int SHA1FinalBits(SHA1Context *context, uint8_t message_bits, + unsigned int length) +{ + static uint8_t masks[8] = { + /* 0 0b00000000 */ 0x00, /* 1 0b10000000 */ 0x80, + /* 2 0b11000000 */ 0xC0, /* 3 0b11100000 */ 0xE0, + /* 4 0b11110000 */ 0xF0, /* 5 0b11111000 */ 0xF8, + /* 6 0b11111100 */ 0xFC, /* 7 0b11111110 */ 0xFE + }; + + static uint8_t markbit[8] = { + /* 0 0b10000000 */ 0x80, /* 1 0b01000000 */ 0x40, + /* 2 0b00100000 */ 0x20, /* 3 0b00010000 */ 0x10, + /* 4 0b00001000 */ 0x08, /* 5 0b00000100 */ 0x04, + /* 6 0b00000010 */ 0x02, /* 7 0b00000001 */ 0x01 + }; + + if (!context) return shaNull; + if (!length) return shaSuccess; + if (context->Corrupted) return context->Corrupted; + if (context->Computed) return context->Corrupted = shaStateError; + if (length >= 8) return context->Corrupted = shaBadParam; + + SHA1AddLength(context, length); + SHA1Finalize(context, + (uint8_t) ((message_bits & masks[length]) | markbit[length])); + + return context->Corrupted; +} + +/* + * 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 element with index 0, + * the last octet of hash in the element with index 19. + * + * 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) return shaNull; + if (!Message_Digest) return shaNull; + if (context->Corrupted) return context->Corrupted; + + if (!context->Computed) + SHA1Finalize(context, 0x80); + + for (i = 0; i < SHA1HashSize; ++i) + Message_Digest[i] = (uint8_t) (context->Intermediate_Hash[i>>2] + >> (8 * ( 3 - ( i & 0x03 ) ))); - return shaSuccess; + 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. - * - * + * SHA1ProcessMessageBlock + * + * Description: + * This helper function will process the next 512 bits of the + * message stored in the Message_Block array. + * + * Parameters: + * context: [in/out] + * The SHA context to update. + * + * 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 Secure Hash Standard. */ 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); -} + /* Constants defined in FIPS 180-3, section 4.2.1 */ + const uint32_t K[4] = { + 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] = ((uint32_t)context->Message_Block[t * 4]) << 24; + W[t] |= ((uint32_t)context->Message_Block[t * 4 + 1]) << 16; + W[t] |= ((uint32_t)context->Message_Block[t * 4 + 2]) << 8; + W[t] |= ((uint32_t)context->Message_Block[t * 4 + 3]); + } + + for (t = 16; t < 80; t++) + W[t] = SHA1_ROTL(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 = SHA1_ROTL(5,A) + SHA_Ch(B, C, D) + E + W[t] + K[0]; + E = D; + D = C; + C = SHA1_ROTL(30,B); + B = A; + A = temp; + } + + for (t = 20; t < 40; t++) { + temp = SHA1_ROTL(5,A) + SHA_Parity(B, C, D) + E + W[t] + K[1]; + E = D; + D = C; + C = SHA1_ROTL(30,B); + B = A; + A = temp; + } + + for (t = 40; t < 60; t++) { + temp = SHA1_ROTL(5,A) + SHA_Maj(B, C, D) + E + W[t] + K[2]; + E = D; + D = C; + C = SHA1_ROTL(30,B); + B = A; + A = temp; + } + + for (t = 60; t < 80; t++) { + temp = SHA1_ROTL(5,A) + SHA_Parity(B, C, D) + E + W[t] + K[3]; + E = D; + D = C; + C = SHA1_ROTL(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; +} + +/* + * SHA1Finalize + * + * Description: + * This helper function finishes off the digest calculations. + * + * Parameters: + * context: [in/out] + * The SHA context to update. + * Pad_Byte: [in] + * The last byte to add to the message block before the 0-padding + * and length. This will contain the last bits of the message + * followed by another single bit. If the message was an + * exact multiple of 8-bits long, Pad_Byte will be 0x80. + * + * Returns: + * sha Error Code. + * + */ +static void SHA1Finalize(SHA1Context *context, uint8_t Pad_Byte) +{ + int i; + SHA1PadMessage(context, Pad_Byte); + /* message may be sensitive, clear it out */ + for (i = 0; i < SHA1_Message_Block_Size; ++i) + context->Message_Block[i] = 0; + context->Length_High = 0; /* and clear length */ + context->Length_Low = 0; + context->Computed = 1; +} + +/* + * SHA1PadMessage + * + * Description: + * According to the standard, the message must be padded to the next + * even multiple of 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 helper function will pad + * the message according to those rules by filling the Message_Block + * array accordingly. When it returns, it can be assumed that the + * message digest has been computed. + * + * Parameters: + * context: [in/out] + * The context to pad. + * Pad_Byte: [in] + * The last byte to add to the message block before the 0-padding + * and length. This will contain the last bits of the message + * followed by another single bit. If the message was an + * exact multiple of 8-bits long, Pad_Byte will be 0x80. + * + * Returns: + * Nothing. + */ +static void SHA1PadMessage(SHA1Context *context, uint8_t Pad_Byte) +{ + /* + * 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 >= (SHA1_Message_Block_Size - 8)) { + context->Message_Block[context->Message_Block_Index++] = Pad_Byte; + while (context->Message_Block_Index < SHA1_Message_Block_Size) + context->Message_Block[context->Message_Block_Index++] = 0; + + SHA1ProcessMessageBlock(context); + } else + context->Message_Block[context->Message_Block_Index++] = Pad_Byte; + + while (context->Message_Block_Index < (SHA1_Message_Block_Size - 8)) + context->Message_Block[context->Message_Block_Index++] = 0; + + /* + * Store the message length as the last 8 octets + */ + context->Message_Block[56] = (uint8_t) (context->Length_High >> 24); + context->Message_Block[57] = (uint8_t) (context->Length_High >> 16); + context->Message_Block[58] = (uint8_t) (context->Length_High >> 8); + context->Message_Block[59] = (uint8_t) (context->Length_High); + context->Message_Block[60] = (uint8_t) (context->Length_Low >> 24); + context->Message_Block[61] = (uint8_t) (context->Length_Low >> 16); + context->Message_Block[62] = (uint8_t) (context->Length_Low >> 8); + context->Message_Block[63] = (uint8_t) (context->Length_Low); + + SHA1ProcessMessageBlock(context); +} +