bnprint.c

来自「包含哈希,对称以及非对称的经典算法 包含经典事例」· C语言 代码 · 共 63 行

/*
 * bnprint.c - Print a bignum, for debugging purposes.
 *
 * Copyright (c) 1995  Colin Plumb.  All rights reserved.
 * For licensing and other legal details, see the file legal.c.
 */
#if HAVE_CONFIG_H
#include "config.h"
#endif

#include <stdio.h>

#if !NO_STRING_H
#include <string.h>
#elif HAVE_STRINGS_H
#include <strings.h>
#endif

#include "bn.h"
#include "bnprint.h"

#include "kludge.h"

int
bnPrint(FILE *f, char const *prefix, struct BigNum const *bn,
	char const *suffix)
{
	unsigned char temp[32];	/* How much to print on one line */
	unsigned len;
	size_t i;

	if (prefix && fputs(prefix, f) < 0)
		return EOF;

	len = (bnBits(bn) + 7)/ 8;

	if (!len) {
		if (putc('0', f) < 0)
			return EOF;
	} else {
		while (len > sizeof(temp)) {
			len -= sizeof(temp);
			bnExtractBigBytes(bn, temp, len, sizeof(temp));
			for (i = 0; i < sizeof(temp); i++)
				if (fprintf(f, "%02X", temp[i]) < 0)
					return EOF;
			if (putc('\\', f) < 0 || putc('\n', f) < 0)
				return EOF;
			if (prefix) {
				i = strlen(prefix);
				while (i--)
					if (putc(' ', f) < 0)
						return EOF;
			}
		}
		bnExtractBigBytes(bn, temp, 0, len);
		for (i = 0; i < len; i++)
			if (fprintf(f, "%02X", temp[i]) < 0)
				return EOF;
	}
	return suffix ?	fputs(suffix, f) : 0;
}