用C语言写的SHA1运行速度非常慢，大约每秒能计算300kb的数据，为什么？
for(i=0;istrlen(message);i++)这一句可能会比较费时，如果message很大的话。
其实只要先int len = strlen(message)，然后
for(i=0;i len; i++)即可。只计算一次。
C语言 是不是每个字符串都包含有一个【字符串结束符】？
C语言里的每个字符串都包含有一个【字符串结束符】– 即是“空字符”，用’\0’表示。
c语言 实现sha1算法
你再知道里面搜“sha1算法”就有。void sha1_finish( sha1_context *ctx, uint8 digest[20] )函数就是你要的。
求祖冲之（zuc）密码算法算法加密C语言实现代码。
这么久没人答，我都弄懂了。祖冲之算法分3个算法ZUC是祖冲之算法的核心，仅产生密键流KS。供EEA3和EIA3调用。EEA3是加密算法，用KS捆绑上用户的密钥，加密用户数据D，变成密文。相当于国际上的RSA、DES、AES算法。作用是对称的加密解密算法EIA3是数据完整性算法，MAC的一种。捆绑上用户的密钥，结合KS，生成散列值。相当于国际上的HMAC结合MD5，SHA1的用法。用于密码授权值的生成和保存。
请教MD5算法 用C语言实现
#include stdio.h
#include stdlib.h
#include string.h
#if defined(__APPLE__)
# define COMMON_DIGEST_FOR_OPENSSL
# include CommonCrypto/CommonDigest.h
# define SHA1 CC_SHA1
#else
# include openssl/md5.h
#endif
// 这是我自己写的函数，用于计算MD5
// 参数 str：要转换的字符串
// 参数 lengthL: 字符串的长度 可以用 strlen(str) 直接获取参数str的长度
// 返回值：MD5字符串
char *str2md5(const char * str, int length) {
int n;
MD5_CTX c;
unsigned char digest[16];
char *out = (char*)malloc(33);
MD5_Init(c);
while (length 0) {
if (length 512) {
MD5_Update(c, str, 512);
} else {
MD5_Update(c, str, length);
}
length -= 512;
str += 512;
}
MD5_Final(digest, c);
for (n = 0; n 16; ++n) {
snprintf((out[n*2]), 16*2, “%02x”, (unsigned int)digest[n]);
}
return out;
}
int main(int argc, char **argv) {
char *output = str2md5(“hello”, strlen(“hello”));
printf(“%s\n”, output);
// 上面会输出 hello的MD5字符串：
// 5d41402abc4b2a76b9719d911017c592
free(output);
return 0;
}
如何使用C语言获取文件的SHA1哈希值
有现成的SHA1算法函数
复制过来。
然后打开文件， 读数据， 调用SHA1函数即可。
#include stdio.h
#include stdlib.h
#include string.h
#include assert.h
#include errno.h
#undef BIG_ENDIAN_HOST
typedef unsigned int u32;
/****************
* Rotate a 32 bit integer by n bytes
*/
#if defined(__GNUC__) defined(__i386__)
static inline u32
rol( u32 x, int n)
{
__asm__(“roll %%cl,%0”
:”=r” (x)
:”0″ (x),”c” (n));
return x;
}
#else
#define rol(x,n) ( ((x) (n)) | ((x) (32-(n))) )
#endif
typedef struct {
u32 h0,h1,h2,h3,h4;
u32 nblocks;
unsigned char buf[64];
int count;
} SHA1_CONTEXT;
void
sha1_init( SHA1_CONTEXT *hd )
{
hd-h0 = 0x67452301;
hd-h1 = 0xefcdab89;
hd-h2 = 0x98badcfe;
hd-h3 = 0x10325476;
hd-h4 = 0xc3d2e1f0;
hd-nblocks = 0;
hd-count = 0;
}
/****************
* Transform the message X which consists of 16 32-bit-words
*/
static void
transform( SHA1_CONTEXT *hd, unsigned char *data )
{
u32 a,b,c,d,e,tm;
u32 x[16];
/* get values from the chaining vars */
a = hd-h0;
b = hd-h1;
c = hd-h2;
d = hd-h3;
e = hd-h4;
#ifdef BIG_ENDIAN_HOST
memcpy( x, data, 64 );
#else
{
int i;
unsigned char *p2;
for(i=0, p2=(unsigned char*)x; i 16; i++, p2 += 4 )
{
p2[3] = *data++;
p2[2] = *data++;
p2[1] = *data++;
p2[0] = *data++;
}
}
#endif
#define K1 0x5A827999L
#define K2 0x6ED9EBA1L
#define K3 0x8F1BBCDCL
#define K4 0xCA62C1D6L
#define F1(x,y,z) ( z ^ ( x ( y ^ z ) ) )
#define F2(x,y,z) ( x ^ y ^ z )
#define F3(x,y,z) ( ( x y ) | ( z ( x | y ) ) )
#define F4(x,y,z) ( x ^ y ^ z )
#define M(i) ( tm = x[i0x0f] ^ x[(i-14)0x0f] \
^ x[(i-8)0x0f] ^ x[(i-3)0x0f] \
, (x[i0x0f] = rol(tm,1)) )
#define R(a,b,c,d,e,f,k,m) do { e += rol( a, 5 ) \
+ f( b, c, d ) \
+ k \
+ m; \
b = rol( b, 30 ); \
} while(0)
R( a, b, c, d, e, F1, K1, x[ 0] );
R( e, a, b, c, d, F1, K1, x[ 1] );
R( d, e, a, b, c, F1, K1, x[ 2] );
R( c, d, e, a, b, F1, K1, x[ 3] );
R( b, c, d, e, a, F1, K1, x[ 4] );
R( a, b, c, d, e, F1, K1, x[ 5] );
R( e, a, b, c, d, F1, K1, x[ 6] );
R( d, e, a, b, c, F1, K1, x[ 7] );
R( c, d, e, a, b, F1, K1, x[ 8] );
R( b, c, d, e, a, F1, K1, x[ 9] );
R( a, b, c, d, e, F1, K1, x[10] );
R( e, a, b, c, d, F1, K1, x[11] );
R( d, e, a, b, c, F1, K1, x[12] );
R( c, d, e, a, b, F1, K1, x[13] );
R( b, c, d, e, a, F1, K1, x[14] );
R( a, b, c, d, e, F1, K1, x[15] );
R( e, a, b, c, d, F1, K1, M(16) );
R( d, e, a, b, c, F1, K1, M(17) );
R( c, d, e, a, b, F1, K1, M(18) );
R( b, c, d, e, a, F1, K1, M(19) );
R( a, b, c, d, e, F2, K2, M(20) );
R( e, a, b, c, d, F2, K2, M(21) );
R( d, e, a, b, c, F2, K2, M(22) );
R( c, d, e, a, b, F2, K2, M(23) );
R( b, c, d, e, a, F2, K2, M(24) );
R( a, b, c, d, e, F2, K2, M(25) );
R( e, a, b, c, d, F2, K2, M(26) );
R( d, e, a, b, c, F2, K2, M(27) );
R( c, d, e, a, b, F2, K2, M(28) );
R( b, c, d, e, a, F2, K2, M(29) );
R( a, b, c, d, e, F2, K2, M(30) );
R( e, a, b, c, d, F2, K2, M(31) );
R( d, e, a, b, c, F2, K2, M(32) );
R( c, d, e, a, b, F2, K2, M(33) );
R( b, c, d, e, a, F2, K2, M(34) );
R( a, b, c, d, e, F2, K2, M(35) );
R( e, a, b, c, d, F2, K2, M(36) );
R( d, e, a, b, c, F2, K2, M(37) );
R( c, d, e, a, b, F2, K2, M(38) );
R( b, c, d, e, a, F2, K2, M(39) );
R( a, b, c, d, e, F3, K3, M(40) );
R( e, a, b, c, d, F3, K3, M(41) );
R( d, e, a, b, c, F3, K3, M(42) );
R( c, d, e, a, b, F3, K3, M(43) );
R( b, c, d, e, a, F3, K3, M(44) );
R( a, b, c, d, e, F3, K3, M(45) );
R( e, a, b, c, d, F3, K3, M(46) );
R( d, e, a, b, c, F3, K3, M(47) );
R( c, d, e, a, b, F3, K3, M(48) );
R( b, c, d, e, a, F3, K3, M(49) );
R( a, b, c, d, e, F3, K3, M(50) );
R( e, a, b, c, d, F3, K3, M(51) );
R( d, e, a, b, c, F3, K3, M(52) );
R( c, d, e, a, b, F3, K3, M(53) );
R( b, c, d, e, a, F3, K3, M(54) );
R( a, b, c, d, e, F3, K3, M(55) );
R( e, a, b, c, d, F3, K3, M(56) );
R( d, e, a, b, c, F3, K3, M(57) );
R( c, d, e, a, b, F3, K3, M(58) );
R( b, c, d, e, a, F3, K3, M(59) );
R( a, b, c, d, e, F4, K4, M(60) );
R( e, a, b, c, d, F4, K4, M(61) );
R( d, e, a, b, c, F4, K4, M(62) );
R( c, d, e, a, b, F4, K4, M(63) );
R( b, c, d, e, a, F4, K4, M(64) );
R( a, b, c, d, e, F4, K4, M(65) );
R( e, a, b, c, d, F4, K4, M(66) );
R( d, e, a, b, c, F4, K4, M(67) );
R( c, d, e, a, b, F4, K4, M(68) );
R( b, c, d, e, a, F4, K4, M(69) );
R( a, b, c, d, e, F4, K4, M(70) );
R( e, a, b, c, d, F4, K4, M(71) );
R( d, e, a, b, c, F4, K4, M(72) );
R( c, d, e, a, b, F4, K4, M(73) );
R( b, c, d, e, a, F4, K4, M(74) );
R( a, b, c, d, e, F4, K4, M(75) );
R( e, a, b, c, d, F4, K4, M(76) );
R( d, e, a, b, c, F4, K4, M(77) );
R( c, d, e, a, b, F4, K4, M(78) );
R( b, c, d, e, a, F4, K4, M(79) );
/* Update chaining vars */
hd-h0 += a;
hd-h1 += b;
hd-h2 += c;
hd-h3 += d;
hd-h4 += e;
}
/* Update the message digest with the contents
* of INBUF with length INLEN.
*/
static void
sha1_write( SHA1_CONTEXT *hd, unsigned char *inbuf, size_t inlen)
{
if( hd-count == 64 ) { /* flush the buffer */
transform( hd, hd-buf );
hd-count = 0;
hd-nblocks++;
}
if( !inbuf )
return;
if( hd-count ) {
for( ; inlen hd-count 64; inlen– )
hd-buf[hd-count++] = *inbuf++;
sha1_write( hd, NULL, 0 );
if( !inlen )
return;
}
while( inlen = 64 ) {
transform( hd, inbuf );
hd-count = 0;
hd-nblocks++;
inlen -= 64;
inbuf += 64;
}
for( ; inlen hd-count 64; inlen– )
hd-buf[hd-count++] = *inbuf++;
}
/* The routine final terminates the computation and
* returns the digest.
* The handle is prepared for a new cycle, but adding bytes to the
* handle will the destroy the returned buffer.
* Returns: 20 bytes representing the digest.
*/
static void
sha1_final(SHA1_CONTEXT *hd)
{
u32 t, msb, lsb;
unsigned char *p;
sha1_write(hd, NULL, 0); /* flush */;
t = hd-nblocks;
/* multiply by 64 to make a byte count */
lsb = t 6;
msb = t 26;
/* add the count */
t = lsb;
if( (lsb += hd-count) t )
msb++;
/* multiply by 8 to make a bit count */
t = lsb;
lsb = 3;
msb = 3;
msb |= t 29;
if( hd-count 56 ) { /* enough room */
hd-buf[hd-count++] = 0x80; /* pad */
while( hd-count 56 )
hd-buf[hd-count++] = 0; /* pad */
}
else { /* need one extra block */
hd-buf[hd-count++] = 0x80; /* pad character */
while( hd-count 64 )
hd-buf[hd-count++] = 0;
sha1_write(hd, NULL, 0); /* flush */;
memset(hd-buf, 0, 56 ); /* fill next block with zeroes */
}
/* append the 64 bit count */
hd-buf[56] = msb 24;
hd-buf[57] = msb 16;
hd-buf[58] = msb 8;
hd-buf[59] = msb ;
hd-buf[60] = lsb 24;
hd-buf[61] = lsb 16;
hd-buf[62] = lsb 8;
hd-buf[63] = lsb ;
transform( hd, hd-buf );
p = hd-buf;
#ifdef BIG_ENDIAN_HOST
#define X(a) do { *(u32*)p = hd-h##a ; p += 4; } while(0)
#else /* little endian */
#define X(a) do { *p++ = hd-h##a 24; *p++ = hd-h##a 16; \
*p++ = hd-h##a 8; *p++ = hd-h##a; } while(0)
#endif
X(0);
X(1);
X(2);
X(3);
X(4);
#undef X
}
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