sha.c

source of perl for linux application,

		memcpy(s->block+offset, bitstr, NBYTES(bitcnt));
		s->blockcnt += bitcnt;
	}
	return(savecnt);
}

/* shabits: updates state for bit-aligned input data */
static ULNG shabits(UCHR *bitstr, ULNG bitcnt, SHA *s)
{
	UINT i;
	UINT gap;
	ULNG nbits;
	UCHR buf[1<<9];
	UINT bufsize = sizeof(buf);
	ULNG bufbits = (ULNG) bufsize << 3;
	UINT nbytes = NBYTES(bitcnt);
	ULNG savecnt = bitcnt;

	gap = 8 - s->blockcnt % 8;
	s->block[s->blockcnt>>3] &= ~0 << gap;
	s->block[s->blockcnt>>3] |= *bitstr >> (8 - gap);
	s->blockcnt += bitcnt < gap ? bitcnt : gap;
	if (bitcnt < gap)
		return(savecnt);
	if (s->blockcnt == s->blocksize)
		s->sha(s, s->block), s->blockcnt = 0;
	if ((bitcnt -= gap) == 0)
		return(savecnt);
	while (nbytes > bufsize) {
		for (i = 0; i < bufsize; i++)
			buf[i] = bitstr[i] << gap | bitstr[i+1] >> (8-gap);
		nbits = bitcnt < bufbits ? bitcnt : bufbits;
		shabytes(buf, nbits, s);
		bitcnt -= nbits, bitstr += bufsize, nbytes -= bufsize;
	}
	for (i = 0; i < nbytes - 1; i++)
		buf[i] = bitstr[i] << gap | bitstr[i+1] >> (8-gap);
	buf[nbytes-1] = bitstr[nbytes-1] << gap;
	shabytes(buf, bitcnt, s);
	return(savecnt);
}

/* shawrite: triggers a state update using data in bitstr/bitcnt */
ULNG shawrite(UCHR *bitstr, ULNG bitcnt, SHA *s)
{
	if (bitcnt < 1)
		return(0);
	if (SHA_LO32(s->lenll += bitcnt) < bitcnt)
		if (SHA_LO32(++s->lenlh) == 0)
			if (SHA_LO32(++s->lenhl) == 0)
				s->lenhh++;
	if (s->blockcnt == 0)
		return(shadirect(bitstr, bitcnt, s));
	else if (s->blockcnt % 8 == 0)
		return(shabytes(bitstr, bitcnt, s));
	else
		return(shabits(bitstr, bitcnt, s));
}

/* shafinish: pads remaining block(s) and computes final digest state */
void shafinish(SHA *s)
{
	UINT lenpos, lhpos, llpos;

	lenpos = s->blocksize == SHA1_BLOCK_BITS ? 448 : 896;
	lhpos  = s->blocksize == SHA1_BLOCK_BITS ?  56 : 120;
	llpos  = s->blocksize == SHA1_BLOCK_BITS ?  60 : 124;
	SETBIT(s->block, s->blockcnt), s->blockcnt++;
	while (s->blockcnt > lenpos)
		if (s->blockcnt < s->blocksize)
			CLRBIT(s->block, s->blockcnt), s->blockcnt++;
		else
			s->sha(s, s->block), s->blockcnt = 0;
	while (s->blockcnt < lenpos)
		CLRBIT(s->block, s->blockcnt), s->blockcnt++;
	if (s->blocksize > SHA1_BLOCK_BITS) {
		w32mem(s->block + 112, s->lenhh);
		w32mem(s->block + 116, s->lenhl);
	}
	w32mem(s->block + lhpos, s->lenlh);
	w32mem(s->block + llpos, s->lenll);
	s->sha(s, s->block);
}

/* shadigest: returns pointer to current digest (binary) */
UCHR *shadigest(SHA *s)
{
	digcpy(s);
	return(s->digest);
}

/* shahex: returns pointer to current digest (hexadecimal) */
char *shahex(SHA *s)
{
	int i;

	digcpy(s);
	s->hex[0] = '\0';
	if (HEXLEN((size_t) s->digestlen) >= sizeof(s->hex))
		return(s->hex);
	for (i = 0; i < s->digestlen; i++)
		sprintf(s->hex+i*2, "%02x", s->digest[i]);
	return(s->hex);
}

/* map: translation map for Base 64 encoding */
static char map[] =
	"ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";

/* encbase64: encodes input (0 to 3 bytes) into Base 64 */
static void encbase64(UCHR *in, int n, char *out)
{
	UCHR byte[3] = {0, 0, 0};

	out[0] = '\0';
	if (n < 1 || n > 3)
		return;
	memcpy(byte, in, n);
	out[0] = map[byte[0] >> 2];
	out[1] = map[((byte[0] & 0x03) << 4) | (byte[1] >> 4)];
	out[2] = map[((byte[1] & 0x0f) << 2) | (byte[2] >> 6)];
	out[3] = map[byte[2] & 0x3f];
	out[n+1] = '\0';
}

/* shabase64: returns pointer to current digest (Base 64) */
char *shabase64(SHA *s)
{
	int n;
	UCHR *q;
	char out[5];

	digcpy(s);
	s->base64[0] = '\0';
	if (B64LEN(s->digestlen) >= sizeof(s->base64))
		return(s->base64);
	for (n = s->digestlen, q = s->digest; n > 3; n -= 3, q += 3) {
		encbase64(q, 3, out);
		strcat(s->base64, out);
	}
	encbase64(q, n, out);
	strcat(s->base64, out);
	return(s->base64);
}

/* shadsize: returns length of digest in bytes */
int shadsize(SHA *s)
{
	return(s->digestlen);
}

/* shadup: duplicates current digest object */
SHA *shadup(SHA *s)
{
	SHA *p;

	SHA_new(0, p, 1, SHA);
	if (p == NULL)
		return(NULL);
	memcpy(p, s, sizeof(SHA));
	return(p);
}

/* shadump: dumps digest object to a human-readable ASCII file */
int shadump(char *file, SHA *s)
{
	int i, j;
	SHA_FILE *f;
	UCHR *p = shadigest(s);

	if (file == NULL || strlen(file) == 0)
		f = SHA_stdout();
	else if ((f = SHA_open(file, "w")) == NULL)
		return(0);
	SHA_fprintf(f, "alg:%d\nH", s->alg);
	for (i = 0; i < 8; i++)
		for (j = 0; j < (s->alg <= 256 ? 4 : 8); j++)
			SHA_fprintf(f, "%s%02x", j==0 ? ":" : "", *p++);
	SHA_fprintf(f, "\nblock");
	for (i = 0; i < (int) (s->blocksize >> 3); i++)
		SHA_fprintf(f, ":%02x", s->block[i]);
	SHA_fprintf(f, "\nblockcnt:%u\n", s->blockcnt);
	SHA_fprintf(f, "lenhh:%lu\nlenhl:%lu\nlenlh:%lu\nlenll:%lu\n",
		(ULNG) LO32(s->lenhh), (ULNG) LO32(s->lenhl),
		(ULNG) LO32(s->lenlh), (ULNG) LO32(s->lenll));
	if (f != SHA_stdout())
		SHA_close(f);
	return(1);
}

/* fgetstr: reads (and returns pointer to) next line of file */
static char *fgetstr(char *line, UINT maxsize, SHA_FILE *f)
{
	char *p;

	if (SHA_feof(f) || maxsize == 0)
		return(NULL);
	for (p = line; !SHA_feof(f) && maxsize > 1; maxsize--)
		if ((*p++ = SHA_getc(f)) == '\n')
			break;
	*p = '\0';
	return(line);
}

/* empty: returns true if line contains only whitespace characters */
static int empty(char *line)
{
	char *p;

	for (p = line; *p; p++)
		if (!isspace(*p))
			return(0);
	return(1);
}

/* getval: null-terminates field value, and sets pointer to rest of line */
static char *getval(char *line, char **pprest)
{
	char *p, *v;

	for (v = line; *v == ':' || isspace(*v); v++)
		;
	for (p = v; *p; p++) {
		if (*p == ':' || isspace(*p)) {
			*p++ = '\0';
			break;
		}
	}
	*pprest = p;
	return(p == v ? NULL : v);
}

/* types of values present in dump file */
#define T_C 1			/* character */
#define T_I 2			/* normal integer */
#define T_L 3			/* 32-bit value */
#define T_Q 4			/* 64-bit value */

/* ldvals: checks next line in dump file against tag, and loads values */
static int ldvals(
	SHA_FILE *f,
	char *tag,
	int type,
	void *pval,
	int reps,
	int base)
{
	char *p, *pr, line[512];
	UCHR *pc = (UCHR *) pval; UINT *pi = (UINT *) pval;
	W32  *pl = (W32  *) pval; W64  *pq = (W64  *) pval;

	while ((p = fgetstr(line, sizeof(line), f)) != NULL)
		if (line[0] != '#' && !empty(line))
			break;
	if (p == NULL || strcmp(getval(line, &pr), tag) != 0)
		return(0);
	while (reps-- > 0) {
		if ((p = getval(pr, &pr)) == NULL)
			return(1);
		switch (type) {
		case T_C: *pc++ = (UCHR) strtoul(p, NULL, base); break;
		case T_I: *pi++ = (UINT) strtoul(p, NULL, base); break;
		case T_L: *pl++ = (W32 ) strtoul(p, NULL, base); break;
		case T_Q: *pq++ = (W64 ) strto64(p            ); break;
		}
	}
	return(1);
}

/* closeall: closes dump file and de-allocates digest object */
static SHA *closeall(SHA_FILE *f, SHA *s)
{
	if (f != NULL && f != SHA_stdin())
		SHA_close(f);
	if (s != NULL)
		shaclose(s);
	return(NULL);
}

/* shaload: creates digest object corresponding to contents of dump file */
SHA *shaload(char *file)
{
	int alg;
	SHA *s = NULL;
	SHA_FILE *f;

	if (file == NULL || strlen(file) == 0)
		f = SHA_stdin();
	else if ((f = SHA_open(file, "r")) == NULL)
		return(NULL);
	if (
		/* avoid parens by exploiting precedence of (type)&-> */
		!ldvals(f,"alg",T_I,(VP)&alg,1,10)			||
		((s = shaopen(alg)) == NULL)				||
		!ldvals(f,"H",alg<=SHA256?T_L:T_Q,(VP)s->H,8,16)	||
		!ldvals(f,"block",T_C,(VP)s->block,s->blocksize/8,16)	||
		!ldvals(f,"blockcnt",T_I,(VP)&s->blockcnt,1,10)		||
		(alg <= SHA256 && s->blockcnt >= SHA1_BLOCK_BITS)	||
		(alg >= SHA384 && s->blockcnt >= SHA384_BLOCK_BITS)	||
		!ldvals(f,"lenhh",T_L,(VP)&s->lenhh,1,10)		||
		!ldvals(f,"lenhl",T_L,(VP)&s->lenhl,1,10)		||
		!ldvals(f,"lenlh",T_L,(VP)&s->lenlh,1,10)		||
		!ldvals(f,"lenll",T_L,(VP)&s->lenll,1,10)
	)
		return(closeall(f, s));
	if (f != SHA_stdin())
		SHA_close(f);
	return(s);
}

/* shaclose: de-allocates digest object */
int shaclose(SHA *s)
{
	if (s != NULL) {
		memset(s, 0, sizeof(SHA));
		SHA_free(s);
	}
	return(0);
}