Commit 85ced3ae authored by Evan Hunt's avatar Evan Hunt
Browse files

Get SHA-1 from RFC 4634 instead of RFC 3174, since it has a clearer license.


git-svn-id: svn://bind10.isc.org/svn/bind10/trunk@1490 e5f2f494-b856-4b98-b285-d166d9295462
parent 82b9f77b
/*
* sha1.c
* Adapted from RFC 3174, "US Secure Hash Algorithm 1", D. Eastlake et al
*
* Description:
* This file implements the Secure Hashing Algorithm 1 as
* defined in FIPS PUB 180-1 published April 17, 1995.
* 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-1, produces a 160-bit message digest for a given
* data stream. It should take about 2**n steps to find a
* The SHA-1 algorithm 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
......@@ -16,25 +21,76 @@
*
* 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
* uses <stdint.h> (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 character, and then
* uses SHA1FinalBits() to hash the final few bits of the input.
*
* Authorship:
* This file is adapted from RFC 4634, by D. Eastlake et al.
* Copyright (C) The Internet Society (2006).
*
* Permission is granted for all uses, commercial and non-commercial,
* of the sample code found in Section 8. Royalty free license to
* use, copy, modify and distribute the software found in Section 8 is
* granted, provided that this document is identified in all material
* mentioning or referencing this software, and provided that
* redistributed derivative works do not contain misleading author or
* version information.
*
* The authors make no representations concerning either the
* merchantability of this software or the suitability of this
* software for any particular purpose. It is provided "as is"
* without express or implied warranty of any kind.
*
*/
#include "sha1.h"
/* Local Function Prototyptes */
static void SHA1PadMessage(SHA1Context *);
static void SHA1Finalize(SHA1Context *, uint8_t Pad_Byte);
static void SHA1PadMessage(SHA1Context *, uint8_t Pad_Byte);
static void SHA1ProcessMessageBlock(SHA1Context *);
/*
* Define functions used by SHA1 hash
*/
static inline uint32_t
SHA_Ch(const uint32_t x, const uint32_t y, const uint32_t z) {
return (((x) & ((y) ^ (z))) ^ (z));
}
static inline uint32_t
SHA_Maj(const uint32_t x, const uint32_t y, const uint32_t z) {
return (((x) & ((y) | (z))) | ((y) & (z)));
}
static inline uint32_t
SHA_Parity(const uint32_t x, const uint32_t y, const uint32_t z) {
return ((x) ^ (y) ^ (z));
}
static inline int
SHA1CircularShift(uint8_t bits, uint32_t word) {
return ((word << bits) | (word >> (32 - bits)));
}
static inline bool
SHA1AddLength(SHA1Context *context, uint32_t length) {
uint32_t addTemp = context->Length_Low;
context->Length_Low += length;
if (context->Length_Low < addTemp && ++context->Length_High == 0) {
return true;
} else {
return false;
}
}
/*
* SHA1Reset
*
......@@ -71,6 +127,129 @@ SHA1Reset(SHA1Context *context) {
return (SHA_SUCCESS);
}
/*
* 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 (SHA_SUCCESS);
}
if (!context || !message_array) {
return (SHA_NULL);
}
if (context->Computed) {
context->Corrupted = SHA_STATEERROR;
return (SHA_STATEERROR);
}
if (context->Corrupted) {
return (context->Corrupted);
}
while(length-- && !context->Corrupted) {
context->Message_Block[context->Message_Block_Index++] =
(*message_array & 0xFF);
if (!SHA1AddLength(context, 8) &&
(context->Message_Block_Index == SHA1_BLOCKSIZE))
{
SHA1ProcessMessageBlock(context);
}
message_array++;
}
return (SHA_SUCCESS);
}
/*
* 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, 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 (SHA_SUCCESS);
}
if (!context) {
return (SHA_NULL);
}
if (context->Computed || (length >= 8) || (length == 0)) {
context->Corrupted = SHA_STATEERROR;
return (SHA_STATEERROR);
}
if (context->Corrupted) {
return (context->Corrupted);
}
SHA1AddLength(context, length);
SHA1Finalize(context,
(uint8_t) ((message_bits & masks[length]) | markbit[length]));
return (SHA_SUCCESS);
}
/*
* SHA1Result
*
......@@ -103,14 +282,7 @@ SHA1Result(SHA1Context *context, uint8_t Message_Digest[SHA1_HASHSIZE]) {
}
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;
SHA1Finalize(context, 0x80);
}
for(i = 0; i < SHA1_HASHSIZE; ++i) {
......@@ -122,81 +294,104 @@ SHA1Result(SHA1Context *context, uint8_t Message_Digest[SHA1_HASHSIZE]) {
}
/*
* SHA1Input
* 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 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 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_BLOCKSIZE; ++i)
context->Message_Block[i] = 0;
context->Length_Low = 0; /* and clear length */
context->Length_High = 0;
context->Computed = 1;
}
/*
* SHA1PadMessage
*
* Description:
* This function accepts an array of octets as the next portion
* of the message.
* 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 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
* 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:
* sha Error Code.
* Nothing.
*
*/
int
SHA1Input(SHA1Context *context, const uint8_t *message_array, unsigned length) {
if (!length) {
return (SHA_SUCCESS);
}
if (!context || !message_array) {
return (SHA_NULL);
}
if (context->Computed) {
context->Corrupted = SHA_STATEERROR;
return (SHA_STATEERROR);
}
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;
}
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_BLOCKSIZE - 8)) {
context->Message_Block[context->Message_Block_Index++] = Pad_Byte;
while (context->Message_Block_Index < SHA1_BLOCKSIZE) {
context->Message_Block[context->Message_Block_Index++] = 0;
}
if (context->Message_Block_Index == 64) {
SHA1ProcessMessageBlock(context);
}
SHA1ProcessMessageBlock(context);
} else
context->Message_Block[context->Message_Block_Index++] = Pad_Byte;
message_array++;
}
while (context->Message_Block_Index < (SHA1_BLOCKSIZE - 8))
context->Message_Block[context->Message_Block_Index++] = 0;
return (SHA_SUCCESS);
}
/*
* 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);
/*
* Define the SHA1 circular left shift
*/
static inline int
SHA1CircularShift(uint8_t bits, uint32_t word) {
return ((word << bits) | (word >> (32 - bits)));
SHA1ProcessMessageBlock(context);
}
/*
* SHA1ProcessMessageBlock
*
* Description:
* This function will process the next 512 bits of the message
* stored in the Message_Block array.
* This helper function will process the next 512 bits of the
* message stored in the Message_Block array.
*
* Parameters:
* None.
......@@ -213,7 +408,8 @@ SHA1CircularShift(uint8_t bits, uint32_t word) {
*/
static void
SHA1ProcessMessageBlock(SHA1Context *context) {
const uint32_t K[] = { /* Constants defined in SHA-1 */
/* Constants defined in FIPS-180-2, section 4.2.1 */
const uint32_t K[] = {
0x5A827999,
0x6ED9EBA1,
0x8F1BBCDC,
......@@ -225,17 +421,17 @@ SHA1ProcessMessageBlock(SHA1Context *context) {
uint32_t A, B, C, D, E; /* Word buffers */
/*
* Initialize the first 16 words in the array W
* 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 = 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] = SHA1CircularShift(1,W[t-3] ^ W[t-8] ^ W[t-14] ^ W[t-16]);
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];
......@@ -244,9 +440,8 @@ SHA1ProcessMessageBlock(SHA1Context *context) {
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];
for (t = 0; t < 20; t++) {
temp = SHA1CircularShift(5,A) + SHA_Ch(B, C, D) + E + W[t] + K[0];
E = D;
D = C;
C = SHA1CircularShift(30,B);
......@@ -254,8 +449,8 @@ SHA1ProcessMessageBlock(SHA1Context *context) {
A = temp;
}
for(t = 20; t < 40; t++) {
temp = SHA1CircularShift(5,A) + (B ^ C ^ D) + E + W[t] + K[1];
for (t = 20; t < 40; t++) {
temp = SHA1CircularShift(5,A) + SHA_Parity(B, C, D) + E + W[t] + K[1];
E = D;
D = C;
C = SHA1CircularShift(30,B);
......@@ -263,9 +458,8 @@ SHA1ProcessMessageBlock(SHA1Context *context) {
A = temp;
}
for(t = 40; t < 60; t++) {
temp = SHA1CircularShift(5,A) +
((B & C) | (B & D) | (C & D)) + E + W[t] + K[2];
for (t = 40; t < 60; t++) {
temp = SHA1CircularShift(5,A) + SHA_Maj(B, C, D) + E + W[t] + K[2];
E = D;
D = C;
C = SHA1CircularShift(30,B);
......@@ -273,8 +467,8 @@ SHA1ProcessMessageBlock(SHA1Context *context) {
A = temp;
}
for(t = 60; t < 80; t++) {
temp = SHA1CircularShift(5,A) + (B ^ C ^ D) + E + W[t] + K[3];
for (t = 60; t < 80; t++) {
temp = SHA1CircularShift(5,A) + SHA_Parity(B, C, D) + E + W[t] + K[3];
E = D;
D = C;
C = SHA1CircularShift(30,B);
......@@ -290,67 +484,3 @@ SHA1ProcessMessageBlock(SHA1Context *context) {
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);
}
......@@ -10,8 +10,24 @@
* single character names, were used because those were the names
* used in the publication.
*
* Please read the file sha1.c for more information.
* Please read the file sha1.cc for more information.
*
* Authorship:
* This file is adapted from RFC 4634, by D. Eastlake et al.
* Copyright (C) The Internet Society (2006).
*
* Permission is granted for all uses, commercial and non-commercial,
* of the sample code found in Section 8. Royalty free license to
* use, copy, modify and distribute the software found in Section 8 is
* granted, provided that this document is identified in all material
* mentioning or referencing this software, and provided that
* redistributed derivative works do not contain misleading author or
* version information.
*
* The authors make no representations concerning either the
* merchantability of this software or the suitability of this
* software for any particular purpose. It is provided "as is"
* without express or implied warranty of any kind.
*/
#ifndef _SHA1_H_
......@@ -35,7 +51,9 @@ enum {
};
enum {
SHA1_HASHSIZE = 20
SHA1_HASHSIZE = 20,
SHA1_HASHBITS = 20,
SHA1_BLOCKSIZE = 64
};
/*
......@@ -56,8 +74,11 @@ typedef struct SHA1Context
/*
* Function Prototypes
*/
int SHA1Reset(SHA1Context *);
int SHA1Input(SHA1Context *, const uint8_t *, unsigned int);
int SHA1Result(SHA1Context *, uint8_t Message_Digest[SHA1_HASHSIZE]);
extern int SHA1Reset(SHA1Context *);
extern int SHA1Input(SHA1Context *, const uint8_t *bytes,
unsigned int bytecount);
extern int SHA1FinalBits(SHA1Context *, const uint8_t bits,
unsigned int bitcount);
extern int SHA1Result(SHA1Context *, uint8_t Message_Digest[SHA1_HASHSIZE]);
#endif
Markdown is supported
0% or .
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment