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Add SHA-256 code from RFC 6234.
This commit is contained in:
Michael R Sweet
parent
8aef2bfedd
commit
9c05f802fc
1
Makefile
1
Makefile
@ -50,6 +50,7 @@ PUBOBJS = \
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pdfio-object.o \
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pdfio-object.o \
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pdfio-page.o \
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pdfio-page.o \
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pdfio-rc4.o \
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pdfio-rc4.o \
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pdfio-sha256.o \
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pdfio-stream.o \
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pdfio-stream.o \
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pdfio-string.o \
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pdfio-string.o \
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pdfio-token.o \
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pdfio-token.o \
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@ -196,6 +196,16 @@ typedef struct _pdfio_rc4_s // RC4 encryption state
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uint8_t i, j; // Current indices into S boxes
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uint8_t i, j; // Current indices into S boxes
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} _pdfio_rc4_t;
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} _pdfio_rc4_t;
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typedef struct _pdfio_sha265_s // SHA-256 hash state
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{
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uint32_t Intermediate_Hash[8]; // Message Digest
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uint32_t Length_High; // Message length in bits
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uint32_t Length_Low; // Message length in bits
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int Message_Block_Index; // Message_Block array index
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uint8_t Message_Block[64]; // 512-bit message blocks
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int Computed; // Is the hash computed?
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int Corrupted; // Cumulative corruption code
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} _pdfio_sha256_t;
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struct _pdfio_array_s
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struct _pdfio_array_s
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{
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{
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@ -325,6 +335,9 @@ extern void _pdfioCryptoMD5Finish(_pdfio_md5_t *pms, uint8_t digest[16]) _PDFIO
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extern void _pdfioCryptoMD5Init(_pdfio_md5_t *pms) _PDFIO_INTERNAL;
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extern void _pdfioCryptoMD5Init(_pdfio_md5_t *pms) _PDFIO_INTERNAL;
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extern void _pdfioCryptoRC4Init(_pdfio_rc4_t *ctx, const uint8_t *key, size_t keylen) _PDFIO_INTERNAL;
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extern void _pdfioCryptoRC4Init(_pdfio_rc4_t *ctx, const uint8_t *key, size_t keylen) _PDFIO_INTERNAL;
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extern void _pdfioCryptoRC4Crypt(_pdfio_rc4_t *ctx, uint8_t *buffer, size_t len) _PDFIO_INTERNAL;
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extern void _pdfioCryptoRC4Crypt(_pdfio_rc4_t *ctx, uint8_t *buffer, size_t len) _PDFIO_INTERNAL;
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extern void _pdfioCryptoSHA256Append(_pdfio_sha256_t *, const uint8_t *bytes, size_t bytecount) _PDFIO_INTERNAL;
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extern void _pdfioCryptoSHA256Init(_pdfio_sha256_t *ctx) _PDFIO_INTERNAL;
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extern void _pdfioCryptoSHA256Finish(_pdfio_sha256_t *ctx, uint8_t *Message_Digest) _PDFIO_INTERNAL;
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extern void _pdfioDictDebug(pdfio_dict_t *dict, FILE *fp) _PDFIO_INTERNAL;
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extern void _pdfioDictDebug(pdfio_dict_t *dict, FILE *fp) _PDFIO_INTERNAL;
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extern void _pdfioDictDelete(pdfio_dict_t *dict) _PDFIO_INTERNAL;
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extern void _pdfioDictDelete(pdfio_dict_t *dict) _PDFIO_INTERNAL;
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480
pdfio-sha256.c
Normal file
480
pdfio-sha256.c
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@ -0,0 +1,480 @@
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//
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// SHA-256 functions for PDFio.
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//
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// Copyright © 2021 by Michael R Sweet.
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// Copyright © 2011 IETF Trust and the persons identified as authors of the
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// code. All rights reserved.
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//
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// Redistribution and use in source and binary forms, with or
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// without modification, are permitted provided that the following
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// conditions are met:
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//
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// - Redistributions of source code must retain the above
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// copyright notice, this list of conditions and
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// the following disclaimer.
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//
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// - Redistributions in binary form must reproduce the above
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// copyright notice, this list of conditions and the following
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// disclaimer in the documentation and/or other materials provided
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// with the distribution.
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//
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// - Neither the name of Internet Society, IETF or IETF Trust, nor
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// the names of specific contributors, may be used to endorse or
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// promote products derived from this software without specific
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// prior written permission.
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//
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// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND
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// CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES,
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// INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
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// MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
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// DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
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// CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
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// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
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// NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
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// LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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// HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
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// CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
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// OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE,
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// EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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//
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/*
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* Description:
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* This file implements the Secure Hash Algorithms SHA-224 and
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* SHA-256 as defined in the U.S. National Institute of Standards
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* and Technology Federal Information Processing Standards
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* Publication (FIPS PUB) 180-3 published in October 2008
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* and formerly defined in its predecessors, FIPS PUB 180-1
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* and FIP PUB 180-2.
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*
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* A combined document showing all algorithms is available at
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* http://csrc.nist.gov/publications/fips/
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* fips180-3/fips180-3_final.pdf
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*
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* The SHA-224 and SHA-256 algorithms produce 224-bit and 256-bit
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* message digests for a given data stream. It should take about
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* 2**n steps to find a message with the same digest as a given
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* message and 2**(n/2) to find any two messages with the same
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* digest, when n is the digest size in bits. Therefore, this
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* algorithm can serve as a means of providing a
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* "fingerprint" for a message.
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*
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* Portability Issues:
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* SHA-224 and SHA-256 are defined in terms of 32-bit "words".
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* This code uses <stdint.h> (included via "sha.h") to define 32-
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* and 8-bit unsigned integer types. If your C compiler does not
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* support 32-bit unsigned integers, this code is not
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* appropriate.
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*
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* Caveats:
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* SHA-224 and SHA-256 are designed to work with messages less
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* than 2^64 bits long. This implementation uses SHA224/256Input()
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* to hash the bits that are a multiple of the size of an 8-bit
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* octet, and then optionally uses SHA224/256FinalBits()
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* to hash the final few bits of the input.
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*/
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#include "pdfio-private.h"
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/* Constants from sha.h */
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enum {
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SHA256_Message_Block_Size = 64,
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SHA256HashSize = 32,
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SHA256HashSizeBits = 256
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};
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enum {
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shaSuccess = 0,
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shaNull, /* Null pointer parameter */
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shaInputTooLong, /* input data too long */
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shaStateError, /* called Input after FinalBits or Result */
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shaBadParam /* passed a bad parameter */
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};
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/* Macros from sha-private.h */
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#define SHA_Ch(x, y, z) (((x) & ((y) ^ (z))) ^ (z))
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#define SHA_Maj(x, y, z) (((x) & ((y) | (z))) | ((y) & (z)))
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#define SHA_Parity(x, y, z) ((x) ^ (y) ^ (z))
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/* Define the SHA shift, rotate left, and rotate right macros */
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#define SHA256_SHR(bits,word) ((word) >> (bits))
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#define SHA256_ROTL(bits,word) \
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(((word) << (bits)) | ((word) >> (32-(bits))))
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#define SHA256_ROTR(bits,word) \
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(((word) >> (bits)) | ((word) << (32-(bits))))
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/* Define the SHA SIGMA and sigma macros */
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#define SHA256_SIGMA0(word) \
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(SHA256_ROTR( 2,word) ^ SHA256_ROTR(13,word) ^ SHA256_ROTR(22,word))
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#define SHA256_SIGMA1(word) \
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(SHA256_ROTR( 6,word) ^ SHA256_ROTR(11,word) ^ SHA256_ROTR(25,word))
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#define SHA256_sigma0(word) \
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(SHA256_ROTR( 7,word) ^ SHA256_ROTR(18,word) ^ SHA256_SHR( 3,word))
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#define SHA256_sigma1(word) \
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(SHA256_ROTR(17,word) ^ SHA256_ROTR(19,word) ^ SHA256_SHR(10,word))
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/*
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* Add "length" to the length.
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* Set Corrupted when overflow has occurred.
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*/
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static uint32_t addTemp;
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#define SHA224_256AddLength(context, length) \
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(addTemp = (context)->Length_Low, (context)->Corrupted = \
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(((context)->Length_Low += (length)) < addTemp) && \
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(++(context)->Length_High == 0) ? shaInputTooLong : \
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(context)->Corrupted )
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/* Local Function Prototypes */
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static int SHA224_256Reset(_pdfio_sha256_t *context, uint32_t *H0);
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static void SHA224_256ProcessMessageBlock(_pdfio_sha256_t *context);
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static void SHA224_256Finalize(_pdfio_sha256_t *context,
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uint8_t Pad_Byte);
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static void SHA224_256PadMessage(_pdfio_sha256_t *context,
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uint8_t Pad_Byte);
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static int SHA224_256ResultN(_pdfio_sha256_t *context,
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uint8_t Message_Digest[ ], int HashSize);
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/* Initial Hash Values: FIPS 180-3 section 5.3.3 */
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static uint32_t SHA256_H0[SHA256HashSize/4] = {
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0x6A09E667, 0xBB67AE85, 0x3C6EF372, 0xA54FF53A,
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0x510E527F, 0x9B05688C, 0x1F83D9AB, 0x5BE0CD19
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};
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/*
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* _pdfioCryptoSHA256Init
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*
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* Description:
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* This function will initialize the _pdfio_sha256_t in preparation
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* for computing a new SHA256 message digest.
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*
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* Parameters:
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* context: [in/out]
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* The context to reset.
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*
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* Returns:
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* sha Error Code.
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*/
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void _pdfioCryptoSHA256Init(_pdfio_sha256_t *context)
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{
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SHA224_256Reset(context, SHA256_H0);
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}
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/*
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* _pdfioCryptoSHA256Append
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*
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* Description:
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* This function accepts an array of octets as the next portion
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* of the message.
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*
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* Parameters:
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* context: [in/out]
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* The SHA context to update.
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* message_array[ ]: [in]
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* An array of octets representing the next portion of
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* the message.
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* length: [in]
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* The length of the message in message_array.
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*
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* Returns:
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* sha Error Code.
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*/
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void
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_pdfioCryptoSHA256Append(_pdfio_sha256_t *context, const uint8_t *message_array,
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size_t length)
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{
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if (!length) return;
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while (length--) {
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context->Message_Block[context->Message_Block_Index++] =
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*message_array;
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if ((SHA224_256AddLength(context, 8) == shaSuccess) &&
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(context->Message_Block_Index == SHA256_Message_Block_Size))
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SHA224_256ProcessMessageBlock(context);
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message_array++;
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}
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}
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/*
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* _pdfioCryptoSHA256Finish
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*
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* Description:
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* This function will return the 256-bit message digest
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* into the Message_Digest array provided by the caller.
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* NOTE:
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* The first octet of hash is stored in the element with index 0,
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* the last octet of hash in the element with index 31.
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*
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* Parameters:
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* context: [in/out]
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* The context to use to calculate the SHA hash.
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* Message_Digest[ ]: [out]
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* Where the digest is returned.
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*
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* Returns:
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* sha Error Code.
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*/
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void
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_pdfioCryptoSHA256Finish(_pdfio_sha256_t *context,
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uint8_t Message_Digest[SHA256HashSize])
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{
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SHA224_256ResultN(context, Message_Digest, SHA256HashSize);
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}
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/*
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* SHA224_256Reset
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*
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* Description:
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* This helper function will initialize the _pdfio_sha256_t in
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* preparation for computing a new SHA-224 or SHA-256 message digest.
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*
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* Parameters:
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* context: [in/out]
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* The context to reset.
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* H0[ ]: [in]
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* The initial hash value array to use.
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*
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* Returns:
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* sha Error Code.
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*/
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static int SHA224_256Reset(_pdfio_sha256_t *context, uint32_t *H0)
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{
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if (!context) return shaNull;
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context->Length_High = context->Length_Low = 0;
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context->Message_Block_Index = 0;
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context->Intermediate_Hash[0] = H0[0];
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context->Intermediate_Hash[1] = H0[1];
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context->Intermediate_Hash[2] = H0[2];
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context->Intermediate_Hash[3] = H0[3];
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context->Intermediate_Hash[4] = H0[4];
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context->Intermediate_Hash[5] = H0[5];
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context->Intermediate_Hash[6] = H0[6];
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context->Intermediate_Hash[7] = H0[7];
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context->Computed = 0;
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context->Corrupted = shaSuccess;
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return shaSuccess;
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}
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/*
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* SHA224_256ProcessMessageBlock
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*
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* Description:
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* This helper function will process the next 512 bits of the
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* message stored in the Message_Block array.
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*
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* Parameters:
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* context: [in/out]
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* The SHA context to update.
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*
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* Returns:
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* Nothing.
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*
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* Comments:
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* Many of the variable names in this code, especially the
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* single character names, were used because those were the
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* names used in the Secure Hash Standard.
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*/
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static void SHA224_256ProcessMessageBlock(_pdfio_sha256_t *context)
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{
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/* Constants defined in FIPS 180-3, section 4.2.2 */
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static const uint32_t K[64] = {
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0x428a2f98, 0x71374491, 0xb5c0fbcf, 0xe9b5dba5, 0x3956c25b,
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0x59f111f1, 0x923f82a4, 0xab1c5ed5, 0xd807aa98, 0x12835b01,
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0x243185be, 0x550c7dc3, 0x72be5d74, 0x80deb1fe, 0x9bdc06a7,
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0xc19bf174, 0xe49b69c1, 0xefbe4786, 0x0fc19dc6, 0x240ca1cc,
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0x2de92c6f, 0x4a7484aa, 0x5cb0a9dc, 0x76f988da, 0x983e5152,
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0xa831c66d, 0xb00327c8, 0xbf597fc7, 0xc6e00bf3, 0xd5a79147,
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0x06ca6351, 0x14292967, 0x27b70a85, 0x2e1b2138, 0x4d2c6dfc,
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0x53380d13, 0x650a7354, 0x766a0abb, 0x81c2c92e, 0x92722c85,
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0xa2bfe8a1, 0xa81a664b, 0xc24b8b70, 0xc76c51a3, 0xd192e819,
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0xd6990624, 0xf40e3585, 0x106aa070, 0x19a4c116, 0x1e376c08,
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0x2748774c, 0x34b0bcb5, 0x391c0cb3, 0x4ed8aa4a, 0x5b9cca4f,
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||||||
|
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_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 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 SHA224_256Finalize(_pdfio_sha256_t *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_High = 0; /* and clear length */
|
||||||
|
context->Length_Low = 0;
|
||||||
|
context->Computed = 1;
|
||||||
|
}
|
||||||
|
|
||||||
|
/*
|
||||||
|
* SHA224_256PadMessage
|
||||||
|
*
|
||||||
|
* 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 SHA224_256PadMessage(_pdfio_sha256_t *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_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 element with index 0,
|
||||||
|
* the last octet of hash in the element with index 27/31.
|
||||||
|
*
|
||||||
|
* 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(_pdfio_sha256_t *context,
|
||||||
|
uint8_t Message_Digest[ ], int HashSize)
|
||||||
|
{
|
||||||
|
int i;
|
||||||
|
|
||||||
|
if (!context) return shaNull;
|
||||||
|
if (!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;
|
||||||
|
}
|
||||||
Loading…
Reference in New Issue
Block a user