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Diffstat (limited to 'source4/lib/crypto/sha1.c')
| -rw-r--r-- | source4/lib/crypto/sha1.c | 390 |
1 files changed, 390 insertions, 0 deletions
diff --git a/source4/lib/crypto/sha1.c b/source4/lib/crypto/sha1.c new file mode 100644 index 0000000000..1b91f8a949 --- /dev/null +++ b/source4/lib/crypto/sha1.c @@ -0,0 +1,390 @@ +/* + This file contains the reference implementation of SHA-1 + from http://www.ietf.org/rfc/rfc3174.txt +*/ +/* + * 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 "includes.h" + +#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(struct SHA1Context *); +static void SHA1ProcessMessageBlock(struct SHA1Context *); + +/* + * SHA1Init (SHA1Reset in the rfc) + * + * 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 SHA1Init(struct 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; +} + +/* + * SHA1Final (SHA1Result in the rfc) + * + * 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 SHA1Final(uint8_t Message_Digest[SHA1HashSize], + struct SHA1Context *context) +{ + 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; +} + +/* + * SHA1Update (SHA1Input in the rfc) + * + * 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 SHA1Update(struct SHA1Context *context, + const uint8_t *message_array, + size_t 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(struct 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(struct 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); +} |