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curl/lib/sha256.c
Jay Satiro 9c1806ae46 build: Disable Visual Studio warning "conditional expression is constant"
- Disable warning C4127 "conditional expression is constant" globally
  in curl_setup.h for when building with Microsoft's compiler.

This mainly affects building with the Visual Studio project files found
in the projects dir.

Prior to this change the cmake and winbuild build systems already
disabled 4127 globally for when building with Microsoft's compiler.
Also, 4127 was already disabled for all build systems in the limited
circumstance of the WHILE_FALSE macro which disabled the warning
specifically for while(0). This commit removes the WHILE_FALSE macro and
all other cruft in favor of disabling globally in curl_setup.

Background:

We have various macros that cause 0 or 1 to be evaluated, which would
cause warning C4127 in Visual Studio. For example this causes it:

    #define Curl_resolver_asynch() 1

Full behavior is not clearly defined and inconsistent across versions.
However it is documented that since VS 2015 Update 3 Microsoft has
addressed this somewhat but not entirely, not warning on while(true) for
example.

Prior to this change some C4127 warnings occurred when I built with
Visual Studio using the generated projects in the projects dir.

Closes https://github.com/curl/curl/pull/4658
2019-12-01 19:01:02 -05:00

268 lines
9.2 KiB
C

/***************************************************************************
* _ _ ____ _
* Project ___| | | | _ \| |
* / __| | | | |_) | |
* | (__| |_| | _ <| |___
* \___|\___/|_| \_\_____|
*
* Copyright (C) 1998 - 2019, Florin Petriuc, <petriuc.florin@gmail.com>
*
* This software is licensed as described in the file COPYING, which
* you should have received as part of this distribution. The terms
* are also available at https://curl.haxx.se/docs/copyright.html.
*
* You may opt to use, copy, modify, merge, publish, distribute and/or sell
* copies of the Software, and permit persons to whom the Software is
* furnished to do so, under the terms of the COPYING file.
*
* This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
* KIND, either express or implied.
*
***************************************************************************/
#include "curl_setup.h"
#ifndef CURL_DISABLE_CRYPTO_AUTH
#include "warnless.h"
#include "curl_sha256.h"
#if defined(USE_OPENSSL)
#include <openssl/opensslv.h>
#if (OPENSSL_VERSION_NUMBER >= 0x0090800fL)
#define USE_OPENSSL_SHA256
#endif
#endif
#ifdef USE_OPENSSL_SHA256
/* When OpenSSL is available we use the SHA256-function from OpenSSL */
#include <openssl/sha.h>
#else
/* When no other crypto library is available we use this code segment */
/* ===== start - public domain SHA256 implementation ===== */
/* This is based on SHA256 implementation in LibTomCrypt that was released into
* public domain by Tom St Denis. */
#define WPA_GET_BE32(a) ((((unsigned long)(a)[0]) << 24) | \
(((unsigned long)(a)[1]) << 16) | \
(((unsigned long)(a)[2]) << 8) | \
((unsigned long)(a)[3]))
#define WPA_PUT_BE32(a, val) \
do { \
(a)[0] = (unsigned char)((((unsigned long) (val)) >> 24) & 0xff); \
(a)[1] = (unsigned char)((((unsigned long) (val)) >> 16) & 0xff); \
(a)[2] = (unsigned char)((((unsigned long) (val)) >> 8) & 0xff); \
(a)[3] = (unsigned char)(((unsigned long) (val)) & 0xff); \
} while(0)
#ifdef HAVE_LONGLONG
#define WPA_PUT_BE64(a, val) \
do { \
(a)[0] = (unsigned char)(((unsigned long long)(val)) >> 56); \
(a)[1] = (unsigned char)(((unsigned long long)(val)) >> 48); \
(a)[2] = (unsigned char)(((unsigned long long)(val)) >> 40); \
(a)[3] = (unsigned char)(((unsigned long long)(val)) >> 32); \
(a)[4] = (unsigned char)(((unsigned long long)(val)) >> 24); \
(a)[5] = (unsigned char)(((unsigned long long)(val)) >> 16); \
(a)[6] = (unsigned char)(((unsigned long long)(val)) >> 8); \
(a)[7] = (unsigned char)(((unsigned long long)(val)) & 0xff); \
} while(0)
#else
#define WPA_PUT_BE64(a, val) \
do { \
(a)[0] = (unsigned char)(((unsigned __int64)(val)) >> 56); \
(a)[1] = (unsigned char)(((unsigned __int64)(val)) >> 48); \
(a)[2] = (unsigned char)(((unsigned __int64)(val)) >> 40); \
(a)[3] = (unsigned char)(((unsigned __int64)(val)) >> 32); \
(a)[4] = (unsigned char)(((unsigned __int64)(val)) >> 24); \
(a)[5] = (unsigned char)(((unsigned __int64)(val)) >> 16); \
(a)[6] = (unsigned char)(((unsigned __int64)(val)) >> 8); \
(a)[7] = (unsigned char)(((unsigned __int64)(val)) & 0xff); \
} while(0)
#endif
typedef struct sha256_state {
#ifdef HAVE_LONGLONG
unsigned long long length;
#else
unsigned __int64 length;
#endif
unsigned long state[8], curlen;
unsigned char buf[64];
} SHA256_CTX;
/* the K array */
static const unsigned long K[64] = {
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
};
/* Various logical functions */
#define RORc(x, y) \
(((((unsigned long)(x) & 0xFFFFFFFFUL) >> (unsigned long)((y) & 31)) | \
((unsigned long)(x) << (unsigned long)(32 - ((y) & 31)))) & 0xFFFFFFFFUL)
#define Ch(x,y,z) (z ^ (x & (y ^ z)))
#define Maj(x,y,z) (((x | y) & z) | (x & y))
#define S(x, n) RORc((x), (n))
#define R(x, n) (((x)&0xFFFFFFFFUL)>>(n))
#define Sigma0(x) (S(x, 2) ^ S(x, 13) ^ S(x, 22))
#define Sigma1(x) (S(x, 6) ^ S(x, 11) ^ S(x, 25))
#define Gamma0(x) (S(x, 7) ^ S(x, 18) ^ R(x, 3))
#define Gamma1(x) (S(x, 17) ^ S(x, 19) ^ R(x, 10))
/* compress 512-bits */
static int sha256_compress(struct sha256_state *md,
unsigned char *buf)
{
unsigned long S[8], W[64];
int i;
/* copy state into S */
for(i = 0; i < 8; i++) {
S[i] = md->state[i];
}
/* copy the state into 512-bits into W[0..15] */
for(i = 0; i < 16; i++)
W[i] = WPA_GET_BE32(buf + (4 * i));
/* fill W[16..63] */
for(i = 16; i < 64; i++) {
W[i] = Gamma1(W[i - 2]) + W[i - 7] + Gamma0(W[i - 15]) +
W[i - 16];
}
/* Compress */
#define RND(a,b,c,d,e,f,g,h,i) \
unsigned long t0 = h + Sigma1(e) + Ch(e, f, g) + K[i] + W[i]; \
unsigned long t1 = Sigma0(a) + Maj(a, b, c); \
d += t0; \
h = t0 + t1;
for(i = 0; i < 64; ++i) {
unsigned long t;
RND(S[0], S[1], S[2], S[3], S[4], S[5], S[6], S[7], i);
t = S[7]; S[7] = S[6]; S[6] = S[5]; S[5] = S[4];
S[4] = S[3]; S[3] = S[2]; S[2] = S[1]; S[1] = S[0]; S[0] = t;
}
/* feedback */
for(i = 0; i < 8; i++) {
md->state[i] = md->state[i] + S[i];
}
return 0;
}
/* Initialize the hash state */
static void SHA256_Init(struct sha256_state *md)
{
md->curlen = 0;
md->length = 0;
md->state[0] = 0x6A09E667UL;
md->state[1] = 0xBB67AE85UL;
md->state[2] = 0x3C6EF372UL;
md->state[3] = 0xA54FF53AUL;
md->state[4] = 0x510E527FUL;
md->state[5] = 0x9B05688CUL;
md->state[6] = 0x1F83D9ABUL;
md->state[7] = 0x5BE0CD19UL;
}
/**
Process a block of memory though the hash
@param md The hash state
@param in The data to hash
@param inlen The length of the data (octets)
@return CRYPT_OK if successful
*/
static int SHA256_Update(struct sha256_state *md,
const unsigned char *in,
unsigned long inlen)
{
unsigned long n;
#define block_size 64
if(md->curlen > sizeof(md->buf))
return -1;
while(inlen > 0) {
if(md->curlen == 0 && inlen >= block_size) {
if(sha256_compress(md, (unsigned char *)in) < 0)
return -1;
md->length += block_size * 8;
in += block_size;
inlen -= block_size;
}
else {
n = CURLMIN(inlen, (block_size - md->curlen));
memcpy(md->buf + md->curlen, in, n);
md->curlen += n;
in += n;
inlen -= n;
if(md->curlen == block_size) {
if(sha256_compress(md, md->buf) < 0)
return -1;
md->length += 8 * block_size;
md->curlen = 0;
}
}
}
return 0;
}
/**
Terminate the hash to get the digest
@param md The hash state
@param out [out] The destination of the hash (32 bytes)
@return CRYPT_OK if successful
*/
static int SHA256_Final(unsigned char *out,
struct sha256_state *md)
{
int i;
if(md->curlen >= sizeof(md->buf))
return -1;
/* increase the length of the message */
md->length += md->curlen * 8;
/* append the '1' bit */
md->buf[md->curlen++] = (unsigned char)0x80;
/* if the length is currently above 56 bytes we append zeros
* then compress. Then we can fall back to padding zeros and length
* encoding like normal.
*/
if(md->curlen > 56) {
while(md->curlen < 64) {
md->buf[md->curlen++] = (unsigned char)0;
}
sha256_compress(md, md->buf);
md->curlen = 0;
}
/* pad up to 56 bytes of zeroes */
while(md->curlen < 56) {
md->buf[md->curlen++] = (unsigned char)0;
}
/* store length */
WPA_PUT_BE64(md->buf + 56, md->length);
sha256_compress(md, md->buf);
/* copy output */
for(i = 0; i < 8; i++)
WPA_PUT_BE32(out + (4 * i), md->state[i]);
return 0;
}
/* ===== end - public domain SHA256 implementation ===== */
#endif
void Curl_sha256it(unsigned char *outbuffer, /* 32 unsigned chars */
const unsigned char *input)
{
SHA256_CTX ctx;
SHA256_Init(&ctx);
SHA256_Update(&ctx, input, curlx_uztoui(strlen((char *)input)));
SHA256_Final(outbuffer, &ctx);
}
#endif /* CURL_DISABLE_CRYPTO_AUTH */