#include "os.h"#include <libsec.h> static void encode(uchar*, u32int*, ulong); extern void _sha1block(uchar*, ulong, u32int*); /* *  we require len to be a multiple of 64 for all but *  the last call.  There must be room in the input buffer *  to pad. */SHA1state*sha1(uchar *p, ulong len, uchar *digest, SHA1state *s){	uchar buf[128];	u32int x[16];	int i;	uchar *e; 	if(s == nil){		s = malloc(sizeof(*s));		if(s == nil)			return nil;		memset(s, 0, sizeof(*s));		s->malloced = 1;	} 	if(s->seeded == 0){		/* seed the state, these constants would look nicer big-endian */		s->state[0] = 0x67452301;		s->state[1] = 0xefcdab89;		s->state[2] = 0x98badcfe;		s->state[3] = 0x10325476;		s->state[4] = 0xc3d2e1f0;		s->seeded = 1;	} 	/* fill out the partial 64 byte block from previous calls */	if(s->blen){		i = 64 - s->blen;		if(len < i)			i = len;		memmove(s->buf + s->blen, p, i);		len -= i;		s->blen += i;		p += i;		if(s->blen == 64){			_sha1block(s->buf, s->blen, s->state);			s->len += s->blen;			s->blen = 0;		}	} 	/* do 64 byte blocks */	i = len & ~0x3f;	if(i){		_sha1block(p, i, s->state);		s->len += i;		len -= i;		p += i;	} 	/* save the left overs if not last call */	if(digest == 0){		if(len){			memmove(s->buf, p, len);			s->blen += len;		}		return s;	} 	/*	 *  this is the last time through, pad what's left with 0x80,	 *  0's, and the input count to create a multiple of 64 bytes	 */	if(s->blen){		p = s->buf;		len = s->blen;	} else {		memmove(buf, p, len);		p = buf;	}	s->len += len;	e = p + len;	if(len < 56)		i = 56 - len;	else		i = 120 - len;	memset(e, 0, i);	*e = 0x80;	len += i; 	/* append the count */	x[0] = s->len>>29;	x[1] = s->len<<3;	encode(p+len, x, 8); 	/* digest the last part */	_sha1block(p, len+8, s->state);	s->len += len+8; 	/* return result and free state */	encode(digest, s->state, SHA1dlen);	if(s->malloced == 1)		free(s);	return nil;} /* *	encodes input (ulong) into output (uchar). Assumes len is *	a multiple of 4. */static voidencode(uchar *output, u32int *input, ulong len){	u32int x;	uchar *e; 	for(e = output + len; output < e;) {		x = *input++;		*output++ = x >> 24;		*output++ = x >> 16;		*output++ = x >> 8;		*output++ = x;	}} DigestState*hmac_sha1(uchar *p, ulong len, uchar *key, ulong klen, uchar *digest,	DigestState *s){	return hmac_x(p, len, key, klen, digest, s, sha1, SHA1dlen);}