sha2.c revision 68e0fce2df0f4ad679781c5daa205466c6c3bb83
/*
* Copyright (C) 2005, 2006 Internet Systems Consortium, Inc. ("ISC")
*
* Permission to use, copy, modify, and distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH
* REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
* AND FITNESS. IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT,
* INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
* LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE
* OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
* PERFORMANCE OF THIS SOFTWARE.
*/
/* $Id: sha2.c,v 1.4 2006/01/31 00:10:57 marka Exp $ */
/* $KAME: sha2.c,v 1.8 2001/11/08 01:07:52 itojun Exp $ */
/*
* sha2.c
*
* Version 1.0.0beta1
*
* Written by Aaron D. Gifford <me@aarongifford.com>
*
* Copyright 2000 Aaron D. Gifford. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* 3. Neither the name of the copyright holder nor the names of contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR(S) AND CONTRIBUTOR(S) ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR(S) OR CONTRIBUTOR(S) BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
*/
#include <config.h>
#include <isc/assertions.h>
/*
* UNROLLED TRANSFORM LOOP NOTE:
* You can define SHA2_UNROLL_TRANSFORM to use the unrolled transform
* loop version for the hash transform rounds (defined using macros
* later in this file). Either define on the command line, for example:
*
* cc -DISC_SHA2_UNROLL_TRANSFORM -o sha2 sha2.c sha2prog.c
*
* or define below:
*
* #define ISC_SHA2_UNROLL_TRANSFORM
*
*/
/*** SHA-256/384/512 Machine Architecture Definitions *****************/
/*
* BYTE_ORDER NOTE:
*
* Please make sure that your system defines BYTE_ORDER. If your
* architecture is little-endian, make sure it also defines
* LITTLE_ENDIAN and that the two (BYTE_ORDER and LITTLE_ENDIAN) are
* equivilent.
*
* If your system does not define the above, then you can do so by
* hand like this:
*
* #define LITTLE_ENDIAN 1234
* #define BIG_ENDIAN 4321
*
* And for little-endian machines, add:
*
* #define BYTE_ORDER LITTLE_ENDIAN
*
* Or for big-endian machines:
*
* #define BYTE_ORDER BIG_ENDIAN
*
* The FreeBSD machine this was written on defines BYTE_ORDER
* made).
*/
#ifndef BYTE_ORDER
#ifndef BIG_ENDIAN
#define BIG_ENDIAN 4321
#endif
#ifndef LITTLE_ENDIAN
#define LITTLE_ENDIAN 1234
#endif
#ifdef WORDS_BIGENDIAN
#define BYTE_ORDER BIG_ENDIAN
#else
#define BYTE_ORDER LITTLE_ENDIAN
#endif
#else
#endif
#endif
/*** SHA-256/384/512 Various Length Definitions ***********************/
/* NOTE: Most of these are in sha2.h */
/*** ENDIAN REVERSAL MACROS *******************************************/
#if BYTE_ORDER == LITTLE_ENDIAN
#define REVERSE32(w,x) { \
isc_uint32_t tmp = (w); \
}
#define REVERSE64(w,x) { \
isc_uint64_t tmp = (w); \
}
#endif /* BYTE_ORDER == LITTLE_ENDIAN */
/*
* Macro for incrementally adding the unsigned 64-bit integer n to the
* unsigned 128-bit integer (represented using a two-element array of
* 64-bit words):
*/
#define ADDINC128(w,n) { \
(w)[0] += (isc_uint64_t)(n); \
if ((w)[0] < (n)) { \
(w)[1]++; \
} \
}
/*** THE SIX LOGICAL FUNCTIONS ****************************************/
/*
* Bit shifting and rotation (used by the six SHA-XYZ logical functions:
*
* NOTE: The naming of R and S appears backwards here (R is a SHIFT and
* S is a ROTATION) because the SHA-256/384/512 description document
* (see http://csrc.nist.gov/cryptval/shs/sha256-384-512.pdf) uses this
* same "backwards" definition.
*/
/* Shift-right (used in SHA-256, SHA-384, and SHA-512): */
#define R(b,x) ((x) >> (b))
/* 32-bit Rotate-right (used in SHA-256): */
#define S32(b,x) (((x) >> (b)) | ((x) << (32 - (b))))
/* 64-bit Rotate-right (used in SHA-384 and SHA-512): */
#define S64(b,x) (((x) >> (b)) | ((x) << (64 - (b))))
/* Two of six logical functions used in SHA-256, SHA-384, and SHA-512: */
#define Ch(x,y,z) (((x) & (y)) ^ ((~(x)) & (z)))
#define Maj(x,y,z) (((x) & (y)) ^ ((x) & (z)) ^ ((y) & (z)))
/* Four of six logical functions used in SHA-256: */
/* Four of six logical functions used in SHA-384 and SHA-512: */
/*** INTERNAL FUNCTION PROTOTYPES *************************************/
/* NOTE: These should not be accessed directly from outside this
* library -- they are intended for private internal visibility/use
* only.
*/
void isc_sha512_last(isc_sha512_t *);
/*** SHA-XYZ INITIAL HASH VALUES AND CONSTANTS ************************/
/* Hash constant words K for SHA-224 and SHA-256: */
0x428a2f98UL, 0x71374491UL, 0xb5c0fbcfUL, 0xe9b5dba5UL,
0x3956c25bUL, 0x59f111f1UL, 0x923f82a4UL, 0xab1c5ed5UL,
0xd807aa98UL, 0x12835b01UL, 0x243185beUL, 0x550c7dc3UL,
0x72be5d74UL, 0x80deb1feUL, 0x9bdc06a7UL, 0xc19bf174UL,
0xe49b69c1UL, 0xefbe4786UL, 0x0fc19dc6UL, 0x240ca1ccUL,
0x2de92c6fUL, 0x4a7484aaUL, 0x5cb0a9dcUL, 0x76f988daUL,
0x983e5152UL, 0xa831c66dUL, 0xb00327c8UL, 0xbf597fc7UL,
0xc6e00bf3UL, 0xd5a79147UL, 0x06ca6351UL, 0x14292967UL,
0x27b70a85UL, 0x2e1b2138UL, 0x4d2c6dfcUL, 0x53380d13UL,
0x650a7354UL, 0x766a0abbUL, 0x81c2c92eUL, 0x92722c85UL,
0xa2bfe8a1UL, 0xa81a664bUL, 0xc24b8b70UL, 0xc76c51a3UL,
0xd192e819UL, 0xd6990624UL, 0xf40e3585UL, 0x106aa070UL,
0x19a4c116UL, 0x1e376c08UL, 0x2748774cUL, 0x34b0bcb5UL,
0x391c0cb3UL, 0x4ed8aa4aUL, 0x5b9cca4fUL, 0x682e6ff3UL,
0x748f82eeUL, 0x78a5636fUL, 0x84c87814UL, 0x8cc70208UL,
0x90befffaUL, 0xa4506cebUL, 0xbef9a3f7UL, 0xc67178f2UL
};
/* Initial hash value H for SHA-224: */
0xc1059ed8UL,
0x367cd507UL,
0x3070dd17UL,
0xf70e5939UL,
0xffc00b31UL,
0x68581511UL,
0x64f98fa7UL,
0xbefa4fa4UL
};
/* Initial hash value H for SHA-256: */
0x6a09e667UL,
0xbb67ae85UL,
0x3c6ef372UL,
0xa54ff53aUL,
0x510e527fUL,
0x9b05688cUL,
0x1f83d9abUL,
0x5be0cd19UL
};
/* Hash constant words K for SHA-384 and SHA-512: */
0x428a2f98d728ae22ULL, 0x7137449123ef65cdULL,
0xb5c0fbcfec4d3b2fULL, 0xe9b5dba58189dbbcULL,
0x3956c25bf348b538ULL, 0x59f111f1b605d019ULL,
0x923f82a4af194f9bULL, 0xab1c5ed5da6d8118ULL,
0xd807aa98a3030242ULL, 0x12835b0145706fbeULL,
0x243185be4ee4b28cULL, 0x550c7dc3d5ffb4e2ULL,
0x72be5d74f27b896fULL, 0x80deb1fe3b1696b1ULL,
0x9bdc06a725c71235ULL, 0xc19bf174cf692694ULL,
0xe49b69c19ef14ad2ULL, 0xefbe4786384f25e3ULL,
0x0fc19dc68b8cd5b5ULL, 0x240ca1cc77ac9c65ULL,
0x2de92c6f592b0275ULL, 0x4a7484aa6ea6e483ULL,
0x5cb0a9dcbd41fbd4ULL, 0x76f988da831153b5ULL,
0x983e5152ee66dfabULL, 0xa831c66d2db43210ULL,
0xb00327c898fb213fULL, 0xbf597fc7beef0ee4ULL,
0xc6e00bf33da88fc2ULL, 0xd5a79147930aa725ULL,
0x06ca6351e003826fULL, 0x142929670a0e6e70ULL,
0x27b70a8546d22ffcULL, 0x2e1b21385c26c926ULL,
0x4d2c6dfc5ac42aedULL, 0x53380d139d95b3dfULL,
0x650a73548baf63deULL, 0x766a0abb3c77b2a8ULL,
0x81c2c92e47edaee6ULL, 0x92722c851482353bULL,
0xa2bfe8a14cf10364ULL, 0xa81a664bbc423001ULL,
0xc24b8b70d0f89791ULL, 0xc76c51a30654be30ULL,
0xd192e819d6ef5218ULL, 0xd69906245565a910ULL,
0xf40e35855771202aULL, 0x106aa07032bbd1b8ULL,
0x19a4c116b8d2d0c8ULL, 0x1e376c085141ab53ULL,
0x2748774cdf8eeb99ULL, 0x34b0bcb5e19b48a8ULL,
0x391c0cb3c5c95a63ULL, 0x4ed8aa4ae3418acbULL,
0x5b9cca4f7763e373ULL, 0x682e6ff3d6b2b8a3ULL,
0x748f82ee5defb2fcULL, 0x78a5636f43172f60ULL,
0x84c87814a1f0ab72ULL, 0x8cc702081a6439ecULL,
0x90befffa23631e28ULL, 0xa4506cebde82bde9ULL,
0xbef9a3f7b2c67915ULL, 0xc67178f2e372532bULL,
0xca273eceea26619cULL, 0xd186b8c721c0c207ULL,
0xeada7dd6cde0eb1eULL, 0xf57d4f7fee6ed178ULL,
0x06f067aa72176fbaULL, 0x0a637dc5a2c898a6ULL,
0x113f9804bef90daeULL, 0x1b710b35131c471bULL,
0x28db77f523047d84ULL, 0x32caab7b40c72493ULL,
0x3c9ebe0a15c9bebcULL, 0x431d67c49c100d4cULL,
0x4cc5d4becb3e42b6ULL, 0x597f299cfc657e2aULL,
0x5fcb6fab3ad6faecULL, 0x6c44198c4a475817ULL
};
/* Initial hash value H for SHA-384: */
0xcbbb9d5dc1059ed8ULL,
0x629a292a367cd507ULL,
0x9159015a3070dd17ULL,
0x152fecd8f70e5939ULL,
0x67332667ffc00b31ULL,
0x8eb44a8768581511ULL,
0xdb0c2e0d64f98fa7ULL,
0x47b5481dbefa4fa4ULL
};
/* Initial hash value H for SHA-512: */
0x6a09e667f3bcc908ULL,
0xbb67ae8584caa73bULL,
0x3c6ef372fe94f82bULL,
0xa54ff53a5f1d36f1ULL,
0x510e527fade682d1ULL,
0x9b05688c2b3e6c1fULL,
0x1f83d9abfb41bd6bULL,
0x5be0cd19137e2179ULL
};
/*
* Constant used by SHA256/384/512_End() functions for converting the
* digest to a readable hexadecimal character string:
*/
static const char *sha2_hex_digits = "0123456789abcdef";
/*** SHA-224: *********************************************************/
void
if (context == (isc_sha256_t *)0) {
return;
}
}
void
}
void
}
char *
int i;
/* Sanity check: */
if (buffer != (char*)0) {
for (i = 0; i < ISC_SHA224_DIGESTLENGTH; i++) {
d++;
}
*buffer = (char)0;
} else {
}
return buffer;
}
char*
{
}
/*** SHA-256: *********************************************************/
void
if (context == (isc_sha256_t *)0) {
return;
}
}
#ifdef ISC_SHA2_UNROLL_TRANSFORM
/* Unrolled SHA-256 round macros: */
#if BYTE_ORDER == LITTLE_ENDIAN
#define ROUND256_0_TO_15(a,b,c,d,e,f,g,h) \
(d) += T1; \
j++
#else /* BYTE_ORDER == LITTLE_ENDIAN */
#define ROUND256_0_TO_15(a,b,c,d,e,f,g,h) \
(d) += T1; \
j++
#endif /* BYTE_ORDER == LITTLE_ENDIAN */
#define ROUND256(a,b,c,d,e,f,g,h) \
(d) += T1; \
j++
int j;
/* Initialize registers with the prev. intermediate value */
j = 0;
do {
/* Rounds 0 to 15 (unrolled): */
ROUND256_0_TO_15(a,b,c,d,e,f,g,h);
ROUND256_0_TO_15(h,a,b,c,d,e,f,g);
ROUND256_0_TO_15(g,h,a,b,c,d,e,f);
ROUND256_0_TO_15(f,g,h,a,b,c,d,e);
ROUND256_0_TO_15(e,f,g,h,a,b,c,d);
ROUND256_0_TO_15(d,e,f,g,h,a,b,c);
ROUND256_0_TO_15(c,d,e,f,g,h,a,b);
ROUND256_0_TO_15(b,c,d,e,f,g,h,a);
} while (j < 16);
/* Now for the remaining rounds to 64: */
do {
ROUND256(a,b,c,d,e,f,g,h);
ROUND256(h,a,b,c,d,e,f,g);
ROUND256(g,h,a,b,c,d,e,f);
ROUND256(f,g,h,a,b,c,d,e);
ROUND256(e,f,g,h,a,b,c,d);
ROUND256(d,e,f,g,h,a,b,c);
ROUND256(c,d,e,f,g,h,a,b);
ROUND256(b,c,d,e,f,g,h,a);
} while (j < 64);
/* Compute the current intermediate hash value */
/* Clean up */
a = b = c = d = e = f = g = h = T1 = 0;
}
#else /* ISC_SHA2_UNROLL_TRANSFORM */
void
int j;
/* Initialize registers with the prev. intermediate value */
j = 0;
do {
#if BYTE_ORDER == LITTLE_ENDIAN
/* Copy data while converting to host byte order */
/* Apply the SHA-256 compression function to update a..h */
#else /* BYTE_ORDER == LITTLE_ENDIAN */
/* Apply the SHA-256 compression function to update a..h with copy */
#endif /* BYTE_ORDER == LITTLE_ENDIAN */
h = g;
g = f;
f = e;
e = d + T1;
d = c;
c = b;
b = a;
j++;
} while (j < 16);
do {
/* Part of the message block expansion: */
/* Apply the SHA-256 compression function to update a..h */
h = g;
g = f;
f = e;
e = d + T1;
d = c;
c = b;
b = a;
j++;
} while (j < 64);
/* Compute the current intermediate hash value */
/* Clean up */
}
#endif /* ISC_SHA2_UNROLL_TRANSFORM */
void
if (len == 0) {
/* Calling with no data is valid - we do nothing */
return;
}
/* Sanity check: */
if (usedspace > 0) {
/* Calculate how much free space is available in the buffer */
/* Fill the buffer completely and process it */
} else {
/* The buffer is not yet full */
/* Clean up: */
return;
}
}
while (len >= ISC_SHA256_BLOCK_LENGTH) {
/* Process as many complete blocks as we can */
}
if (len > 0) {
/* There's left-overs, so save 'em */
}
/* Clean up: */
}
void
unsigned int usedspace;
/* Sanity check: */
/* If no digest buffer is passed, we don't bother doing this: */
if (digest != (isc_uint8_t*)0) {
#if BYTE_ORDER == LITTLE_ENDIAN
/* Convert FROM host byte order */
#endif
if (usedspace > 0) {
/* Begin padding with a 1 bit: */
if (usedspace <= ISC_SHA256_SHORT_BLOCK_LENGTH) {
/* Set-up for the last transform: */
} else {
if (usedspace < ISC_SHA256_BLOCK_LENGTH) {
}
/* Do second-to-last transform: */
/* And set-up for the last transform: */
}
} else {
/* Set-up for the last transform: */
/* Begin padding with a 1 bit: */
}
/* Set the bit count: */
/* Final transform: */
#if BYTE_ORDER == LITTLE_ENDIAN
{
/* Convert TO host byte order */
int j;
for (j = 0; j < 8; j++) {
}
}
#else
#endif
}
/* Clean up state data: */
usedspace = 0;
}
char *
int i;
/* Sanity check: */
if (buffer != (char*)0) {
for (i = 0; i < ISC_SHA256_DIGESTLENGTH; i++) {
d++;
}
*buffer = (char)0;
} else {
}
return buffer;
}
char *
{
}
/*** SHA-512: *********************************************************/
void
if (context == (isc_sha512_t *)0) {
return;
}
}
#ifdef ISC_SHA2_UNROLL_TRANSFORM
/* Unrolled SHA-512 round macros: */
#if BYTE_ORDER == LITTLE_ENDIAN
#define ROUND512_0_TO_15(a,b,c,d,e,f,g,h) \
(d) += T1, \
j++
#else /* BYTE_ORDER == LITTLE_ENDIAN */
#define ROUND512_0_TO_15(a,b,c,d,e,f,g,h) \
(d) += T1; \
j++
#endif /* BYTE_ORDER == LITTLE_ENDIAN */
#define ROUND512(a,b,c,d,e,f,g,h) \
(d) += T1; \
j++
int j;
/* Initialize registers with the prev. intermediate value */
j = 0;
do {
ROUND512_0_TO_15(a,b,c,d,e,f,g,h);
ROUND512_0_TO_15(h,a,b,c,d,e,f,g);
ROUND512_0_TO_15(g,h,a,b,c,d,e,f);
ROUND512_0_TO_15(f,g,h,a,b,c,d,e);
ROUND512_0_TO_15(e,f,g,h,a,b,c,d);
ROUND512_0_TO_15(d,e,f,g,h,a,b,c);
ROUND512_0_TO_15(c,d,e,f,g,h,a,b);
ROUND512_0_TO_15(b,c,d,e,f,g,h,a);
} while (j < 16);
/* Now for the remaining rounds up to 79: */
do {
ROUND512(a,b,c,d,e,f,g,h);
ROUND512(h,a,b,c,d,e,f,g);
ROUND512(g,h,a,b,c,d,e,f);
ROUND512(f,g,h,a,b,c,d,e);
ROUND512(e,f,g,h,a,b,c,d);
ROUND512(d,e,f,g,h,a,b,c);
ROUND512(c,d,e,f,g,h,a,b);
ROUND512(b,c,d,e,f,g,h,a);
} while (j < 80);
/* Compute the current intermediate hash value */
/* Clean up */
a = b = c = d = e = f = g = h = T1 = 0;
}
#else /* ISC_SHA2_UNROLL_TRANSFORM */
void
int j;
/* Initialize registers with the prev. intermediate value */
j = 0;
do {
#if BYTE_ORDER == LITTLE_ENDIAN
/* Convert TO host byte order */
/* Apply the SHA-512 compression function to update a..h */
#else /* BYTE_ORDER == LITTLE_ENDIAN */
/* Apply the SHA-512 compression function to update a..h with copy */
#endif /* BYTE_ORDER == LITTLE_ENDIAN */
h = g;
g = f;
f = e;
e = d + T1;
d = c;
c = b;
b = a;
j++;
} while (j < 16);
do {
/* Part of the message block expansion: */
/* Apply the SHA-512 compression function to update a..h */
h = g;
g = f;
f = e;
e = d + T1;
d = c;
c = b;
b = a;
j++;
} while (j < 80);
/* Compute the current intermediate hash value */
/* Clean up */
}
#endif /* ISC_SHA2_UNROLL_TRANSFORM */
if (len == 0) {
/* Calling with no data is valid - we do nothing */
return;
}
/* Sanity check: */
if (usedspace > 0) {
/* Calculate how much free space is available in the buffer */
/* Fill the buffer completely and process it */
} else {
/* The buffer is not yet full */
/* Clean up: */
return;
}
}
while (len >= ISC_SHA512_BLOCK_LENGTH) {
/* Process as many complete blocks as we can */
}
if (len > 0) {
/* There's left-overs, so save 'em */
}
/* Clean up: */
}
unsigned int usedspace;
#if BYTE_ORDER == LITTLE_ENDIAN
/* Convert FROM host byte order */
#endif
if (usedspace > 0) {
/* Begin padding with a 1 bit: */
if (usedspace <= ISC_SHA512_SHORT_BLOCK_LENGTH) {
/* Set-up for the last transform: */
} else {
if (usedspace < ISC_SHA512_BLOCK_LENGTH) {
}
/* Do second-to-last transform: */
/* And set-up for the last transform: */
}
} else {
/* Prepare for final transform: */
/* Begin padding with a 1 bit: */
}
/* Store the length of input data (in bits): */
/* Final transform: */
}
/* Sanity check: */
/* If no digest buffer is passed, we don't bother doing this: */
if (digest != (isc_uint8_t*)0) {
/* Save the hash data for output: */
#if BYTE_ORDER == LITTLE_ENDIAN
{
/* Convert TO host byte order */
int j;
for (j = 0; j < 8; j++) {
}
}
#else
#endif
}
/* Zero out state data */
}
char *
int i;
/* Sanity check: */
if (buffer != (char*)0) {
for (i = 0; i < ISC_SHA512_DIGESTLENGTH; i++) {
d++;
}
*buffer = (char)0;
} else {
}
return buffer;
}
char *
{
}
/*** SHA-384: *********************************************************/
void
if (context == (isc_sha384_t *)0) {
return;
}
}
void
}
void
/* Sanity check: */
/* If no digest buffer is passed, we don't bother doing this: */
if (digest != (isc_uint8_t*)0) {
/* Save the hash data for output: */
#if BYTE_ORDER == LITTLE_ENDIAN
{
/* Convert TO host byte order */
int j;
for (j = 0; j < 6; j++) {
}
}
#else
#endif
}
/* Zero out state data */
}
char *
int i;
/* Sanity check: */
if (buffer != (char*)0) {
for (i = 0; i < ISC_SHA384_DIGESTLENGTH; i++) {
d++;
}
*buffer = (char)0;
} else {
}
return buffer;
}
char*
{
}