/*************************** sha224-256.c ***************************/ /********************* See RFC 4634 for details *********************/ /* * Description: * This file implements the Secure Hash Signature Standard * algorithms as defined in the National Institute of Standards * and Technology Federal Information Processing Standards * Publication (FIPS PUB) 180-1 published on April 17, 1995, 180-2 * published on August 1, 2002, and the FIPS PUB 180-2 Change * Notice published on February 28, 2004. * * A combined document showing all algorithms is available at * http://csrc.nist.gov/publications/fips/ * fips180-2/fips180-2withchangenotice.pdf * * The SHA-224 and SHA-256 algorithms produce 224-bit and 256-bit * message digests 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-224 and SHA-256 are defined in terms of 32-bit "words". * This code 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-224 and SHA-256 are designed to work with messages less * than 2^64 bits long. This implementation uses SHA224/256Input() * to hash the bits that are a multiple of the size of an 8-bit * character, and then uses SHA224/256FinalBits() to hash the * final few bits of the input. */ #include "sha.h" #include "sha-private.h" /* Define the SHA shift, rotate left and rotate right macro */ #define SHA256_SHR(bits,word) ((word) >> (bits)) #define SHA256_ROTL(bits,word) \ (((word) << (bits)) | ((word) >> (32-(bits)))) #define SHA256_ROTR(bits,word) \ (((word) >> (bits)) | ((word) << (32-(bits)))) /* Define the SHA SIGMA and sigma macros */ #define SHA256_SIGMA0(word) \ (SHA256_ROTR( 2,word) ^ SHA256_ROTR(13,word) ^ SHA256_ROTR(22,word)) #define SHA256_SIGMA1(word) \ (SHA256_ROTR( 6,word) ^ SHA256_ROTR(11,word) ^ SHA256_ROTR(25,word)) #define SHA256_sigma0(word) \ (SHA256_ROTR( 7,word) ^ SHA256_ROTR(18,word) ^ SHA256_SHR( 3,word)) #define SHA256_sigma1(word) \ (SHA256_ROTR(17,word) ^ SHA256_ROTR(19,word) ^ SHA256_SHR(10,word)) /* * add "length" to the length */ static uint32_t addTemp32; #define SHA224_256AddLength(context, length) \ (addTemp32 = (context)->Length_Low, (context)->Corrupted = \ (((context)->Length_Low += (length)) < addTemp32) && \ (++(context)->Length_High == 0) ? 1 : 0) /* Local Function Prototypes */ static void SHA224_256Finalize(SHA256Context *context, uint8_t Pad_Byte); static void SHA224_256PadMessage(SHA256Context *context, uint8_t Pad_Byte); static void SHA224_256ProcessMessageBlock(SHA256Context *context); static int SHA224_256Reset(SHA256Context *context, uint32_t *H0); static int SHA224_256ResultN(SHA256Context *context, uint8_t Message_Digest[], int HashSize); /* Initial Hash Values: FIPS-180-2 Change Notice 1 */ static uint32_t SHA224_H0[SHA256HashSize/4] = { 0xC1059ED8, 0x367CD507, 0x3070DD17, 0xF70E5939, 0xFFC00B31, 0x68581511, 0x64F98FA7, 0xBEFA4FA4 }; /* Initial Hash Values: FIPS-180-2 section 5.3.2 */ static uint32_t SHA256_H0[SHA256HashSize/4] = { 0x6A09E667, 0xBB67AE85, 0x3C6EF372, 0xA54FF53A, 0x510E527F, 0x9B05688C, 0x1F83D9AB, 0x5BE0CD19 }; /* * SHA224Reset * * Description: * This function will initialize the SHA384Context in preparation * for computing a new SHA224 message digest. * * Parameters: * context: [in/out] * The context to reset. * * Returns: * sha Error Code. */ int SHA224Reset(SHA224Context *context) { return SHA224_256Reset(context, SHA224_H0); } /* * SHA224Input * * 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 SHA224Input(SHA224Context *context, const uint8_t *message_array, unsigned int length) { return SHA256Input(context, message_array, length); } /* * SHA224FinalBits * * 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 SHA224FinalBits( SHA224Context *context, const uint8_t message_bits, unsigned int length) { return SHA256FinalBits(context, message_bits, length); } /* * SHA224Result * * Description: * This function will return the 224-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 28th element. * * Parameters: * context: [in/out] * The context to use to calculate the SHA hash. * Message_Digest: [out] * Where the digest is returned. * * Returns: * sha Error Code. */ int SHA224Result(SHA224Context *context, uint8_t Message_Digest[SHA224HashSize]) { return SHA224_256ResultN(context, Message_Digest, SHA224HashSize); } /* * SHA256Reset * * Description: * This function will initialize the SHA256Context in preparation * for computing a new SHA256 message digest. * * Parameters: * context: [in/out] * The context to reset. * * Returns: * sha Error Code. */ int SHA256Reset(SHA256Context *context) { return SHA224_256Reset(context, SHA256_H0); } /* * SHA256Input * * 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 SHA256Input(SHA256Context *context, const uint8_t *message_array, unsigned int 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); if (!SHA224_256AddLength(context, 8) && (context->Message_Block_Index == SHA256_Message_Block_Size)) SHA224_256ProcessMessageBlock(context); message_array++; } return shaSuccess; } /* * SHA256FinalBits * * 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 SHA256FinalBits(SHA256Context *context, const uint8_t message_bits, unsigned int length) { 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 }; 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 (!length) return shaSuccess; if (!context) return shaNull; if ((context->Computed) || (length >= 8) || (length == 0)) { context->Corrupted = shaStateError; return shaStateError; } if (context->Corrupted) return context->Corrupted; SHA224_256AddLength(context, length); SHA224_256Finalize(context, (uint8_t) ((message_bits & masks[length]) | markbit[length])); return shaSuccess; } /* * SHA256Result * * Description: * This function will return the 256-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 32nd element. * * Parameters: * context: [in/out] * The context to use to calculate the SHA hash. * Message_Digest: [out] * Where the digest is returned. * * Returns: * sha Error Code. */ int SHA256Result(SHA256Context *context, uint8_t Message_Digest[]) { return SHA224_256ResultN(context, Message_Digest, SHA256HashSize); } /* * SHA224_256Finalize * * 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 digest 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 SHA224_256Finalize(SHA256Context *context, uint8_t Pad_Byte) { int i; SHA224_256PadMessage(context, Pad_Byte); /* message may be sensitive, so clear it out */ for (i = 0; i < SHA256_Message_Block_Size; ++i) context->Message_Block[i] = 0; context->Length_Low = 0; /* and clear length */ context->Length_High = 0; context->Computed = 1; } /* * SHA224_256PadMessage * * 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 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 digest 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 SHA224_256PadMessage(SHA256Context *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 >= (SHA256_Message_Block_Size-8)) { context->Message_Block[context->Message_Block_Index++] = Pad_Byte; while (context->Message_Block_Index < SHA256_Message_Block_Size) context->Message_Block[context->Message_Block_Index++] = 0; SHA224_256ProcessMessageBlock(context); } else context->Message_Block[context->Message_Block_Index++] = Pad_Byte; while (context->Message_Block_Index < (SHA256_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); SHA224_256ProcessMessageBlock(context); } /* * SHA224_256ProcessMessageBlock * * Description: * This 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 publication. */ static void SHA224_256ProcessMessageBlock(SHA256Context *context) { /* Constants defined in FIPS-180-2, section 4.2.2 */ static const uint32_t K[64] = { 0x428a2f98, 0x71374491, 0xb5c0fbcf, 0xe9b5dba5, 0x3956c25b, 0x59f111f1, 0x923f82a4, 0xab1c5ed5, 0xd807aa98, 0x12835b01, 0x243185be, 0x550c7dc3, 0x72be5d74, 0x80deb1fe, 0x9bdc06a7, 0xc19bf174, 0xe49b69c1, 0xefbe4786, 0x0fc19dc6, 0x240ca1cc, 0x2de92c6f, 0x4a7484aa, 0x5cb0a9dc, 0x76f988da, 0x983e5152, 0xa831c66d, 0xb00327c8, 0xbf597fc7, 0xc6e00bf3, 0xd5a79147, 0x06ca6351, 0x14292967, 0x27b70a85, 0x2e1b2138, 0x4d2c6dfc, 0x53380d13, 0x650a7354, 0x766a0abb, 0x81c2c92e, 0x92722c85, 0xa2bfe8a1, 0xa81a664b, 0xc24b8b70, 0xc76c51a3, 0xd192e819, 0xd6990624, 0xf40e3585, 0x106aa070, 0x19a4c116, 0x1e376c08, 0x2748774c, 0x34b0bcb5, 0x391c0cb3, 0x4ed8aa4a, 0x5b9cca4f, 0x682e6ff3, 0x748f82ee, 0x78a5636f, 0x84c87814, 0x8cc70208, 0x90befffa, 0xa4506ceb, 0xbef9a3f7, 0xc67178f2 }; int t, t4; /* Loop counter */ uint32_t temp1, temp2; /* Temporary word value */ uint32_t W[64]; /* Word sequence */ uint32_t A, B, C, D, E, F, G, H; /* Word buffers */ /* * Initialize the first 16 words in the array W */ for (t = t4 = 0; t < 16; t++, t4 += 4) W[t] = (((uint32_t)context->Message_Block[t4]) << 24) | (((uint32_t)context->Message_Block[t4 + 1]) << 16) | (((uint32_t)context->Message_Block[t4 + 2]) << 8) | (((uint32_t)context->Message_Block[t4 + 3])); for (t = 16; t < 64; t++) W[t] = SHA256_sigma1(W[t-2]) + W[t-7] + SHA256_sigma0(W[t-15]) + 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]; F = context->Intermediate_Hash[5]; G = context->Intermediate_Hash[6]; H = context->Intermediate_Hash[7]; for (t = 0; t < 64; t++) { temp1 = H + SHA256_SIGMA1(E) + SHA_Ch(E,F,G) + K[t] + W[t]; temp2 = SHA256_SIGMA0(A) + SHA_Maj(A,B,C); H = G; G = F; F = E; E = D + temp1; D = C; C = B; B = A; A = temp1 + temp2; } 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->Intermediate_Hash[5] += F; context->Intermediate_Hash[6] += G; context->Intermediate_Hash[7] += H; context->Message_Block_Index = 0; } /* * SHA224_256Reset * * Description: * This helper function will initialize the SHA256Context in * preparation for computing a new SHA256 message digest. * * Parameters: * context: [in/out] * The context to reset. * H0 * The initial hash value to use. * * Returns: * sha Error Code. */ static int SHA224_256Reset(SHA256Context *context, uint32_t *H0) { if (!context) return shaNull; context->Length_Low = 0; context->Length_High = 0; context->Message_Block_Index = 0; context->Intermediate_Hash[0] = H0[0]; context->Intermediate_Hash[1] = H0[1]; context->Intermediate_Hash[2] = H0[2]; context->Intermediate_Hash[3] = H0[3]; context->Intermediate_Hash[4] = H0[4]; context->Intermediate_Hash[5] = H0[5]; context->Intermediate_Hash[6] = H0[6]; context->Intermediate_Hash[7] = H0[7]; context->Computed = 0; context->Corrupted = 0; return shaSuccess; } /* * SHA224_256ResultN * * Description: * This helper function will return the 224-bit or 256-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 28th/32nd element. * * Parameters: * context: [in/out] * The context to use to calculate the SHA hash. * Message_Digest: [out] * Where the digest is returned. * HashSize: [in] * The size of the hash, either 28 or 32. * * Returns: * sha Error Code. */ static int SHA224_256ResultN(SHA256Context *context, uint8_t Message_Digest[], int HashSize) { int i; if (!context || !Message_Digest) return shaNull; if (context->Corrupted) return context->Corrupted; if (!context->Computed) SHA224_256Finalize(context, 0x80); for (i = 0; i < HashSize; ++i) Message_Digest[i] = (uint8_t) (context->Intermediate_Hash[i>>2] >> 8 * ( 3 - ( i & 0x03 ) )); return shaSuccess; }