/* a_mbstr.c */
/* Written by Dr Stephen N Henson (shenson@bigfoot.com) for the OpenSSL
 * project 1999.
 */
/* ====================================================================
 * Copyright (c) 1999 The OpenSSL Project.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer. 
 *
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in
 *    the documentation and/or other materials provided with the
 *    distribution.
 *
 * 3. All advertising materials mentioning features or use of this
 *    software must display the following acknowledgment:
 *    "This product includes software developed by the OpenSSL Project
 *    for use in the OpenSSL Toolkit. (http://www.OpenSSL.org/)"
 *
 * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
 *    endorse or promote products derived from this software without
 *    prior written permission. For written permission, please contact
 *    licensing@OpenSSL.org.
 *
 * 5. Products derived from this software may not be called "OpenSSL"
 *    nor may "OpenSSL" appear in their names without prior written
 *    permission of the OpenSSL Project.
 *
 * 6. Redistributions of any form whatsoever must retain the following
 *    acknowledgment:
 *    "This product includes software developed by the OpenSSL Project
 *    for use in the OpenSSL Toolkit (http://www.OpenSSL.org/)"
 *
 * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
 * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE OpenSSL PROJECT OR
 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
 * OF THE POSSIBILITY OF SUCH DAMAGE.
 * ====================================================================
 *
 * This product includes cryptographic software written by Eric Young
 * (eay@cryptsoft.com).  This product includes software written by Tim
 * Hudson (tjh@cryptsoft.com).
 *
 */

#include <stdio.h>
#include <ctype.h>
#include "cryptlib.h"
#include <openssl/asn1.h>

static int traverse_string(const unsigned char *p, int len, int inform,
		 int (*rfunc)(unsigned long value, void *in), void *arg);
static int in_utf8(unsigned long value, void *arg);
static int out_utf8(unsigned long value, void *arg);
static int type_str(unsigned long value, void *arg);
static int cpy_asc(unsigned long value, void *arg);
static int cpy_bmp(unsigned long value, void *arg);
static int cpy_univ(unsigned long value, void *arg);
static int cpy_utf8(unsigned long value, void *arg);
static int is_printable(unsigned long value);

/* This is the default mask for the mbstring functions: it is designed
 * to be a "safe" DirectoryString. Netscape messenger crashes when it
 * receives a certificate containing a BMPString so by default we don't
 * use them unless we have to.
 */

static long dirstring_mask = B_ASN1_PRINTABLESTRING
				| B_ASN1_T61STRING | B_ASN1_BMPSTRING;

void ASN1_STRING_set_default_mask(unsigned long mask)
{
	dirstring_mask = mask;
}

unsigned long ASN1_STRING_get_default_mask(void)
{
	return dirstring_mask;
}

/* This function sets the default to various "flavours" of configuration.
 * based on an ASCII string. Currently this is:
 * MASK:XXXX : a numerical mask value.
 * nobmp : Don't use BMPStrings (just Printable, T61).
 * pkix : PKIX recommendation in RFC2459.
 * utf8only : only use UTF8Strings (RFC2459 recommendation for 2004).
 * default:   the default value, Printable, T61, BMP.
 */

int ASN1_STRING_set_default_mask_asc(char *p)
{
	unsigned long mask;
	char *end;
	if(!strncmp(p, "MASK:", 5)) {
		if(!p[5]) return 0;
		mask = strtoul(p + 5, &end, 0);
		if(*end) return 0;
	} else if(!strcmp(p, "nobmp"))
			 mask = B_ASN1_PRINTABLESTRING | B_ASN1_T61STRING;
	else if(!strcmp(p, "pkix"))
			mask = B_ASN1_PRINTABLESTRING | B_ASN1_BMPSTRING;
	else if(!strcmp(p, "utf8only")) mask = B_ASN1_UTF8STRING;
	else if(!strcmp(p, "default"))
	    mask = B_ASN1_PRINTABLESTRING | B_ASN1_T61STRING | B_ASN1_BMPSTRING;
	else return 0;
	ASN1_STRING_set_default_mask(mask);
	return 1;
}

/* These functions take a string in UTF8, ASCII or multibyte form and
 * a mask of permissible ASN1 string types. It then works out the minimal
 * type (using the order Printable < IA5 < T61 < BMP < Universal < UTF8)
 * and creates a string of the correct type with the supplied data.
 * Yes this is horrible: it has to be :-(
 * The 'ncopy' form checks minimum and maximum size limits too.
 */

int ASN1_mbstring_copy(ASN1_STRING **out, const unsigned char *in, int len,
					int inform, unsigned long mask)
{
	return ASN1_mbstring_ncopy(out, in, len, inform, mask, 0, 0);
}

int ASN1_mbstring_ncopy(ASN1_STRING **out, const unsigned char *in, int len,
					int inform, unsigned long mask, 
					long minsize, long maxsize)
{
	int str_type;
	int ret;
	int outform, outlen;
	ASN1_STRING *dest;
	unsigned char *p;
	int nchar;
	char strbuf[32];
	int (*cpyfunc)(unsigned long,void *) = NULL;
	if(len == -1) len = strlen((const char *)in);
	if(!mask) mask = dirstring_mask;

	/* First do a string check and work out the number of characters */
	switch(inform) {

		case MBSTRING_BMP:
		if(len & 1) {
			ASN1err(ASN1_F_ASN1_MBSTRING_COPY,
					 ASN1_R_INVALID_BMPSTRING_LENGTH);
			return -1;
		}
		nchar = len >> 1;
		break;

		case MBSTRING_UNIV:
		if(len & 3) {
			ASN1err(ASN1_F_ASN1_MBSTRING_COPY,
					 ASN1_R_INVALID_UNIVERSALSTRING_LENGTH);
			return -1;
		}
		nchar = len >> 2;
		break;

		case MBSTRING_UTF8:
		nchar = 0;
		/* This counts the characters and does utf8 syntax checking */
		ret = traverse_string(in, len, MBSTRING_UTF8, in_utf8, &nchar);
		if(ret < 0) {
			ASN1err(ASN1_F_ASN1_MBSTRING_COPY,
						 ASN1_R_INVALID_UTF8STRING);
			return -1;
		}
		break;

		case MBSTRING_ASC:
		nchar = len;
		break;

		default:
		ASN1err(ASN1_F_ASN1_MBSTRING_COPY, ASN1_R_UNKNOWN_FORMAT);
		return -1;
	}

	if(minsize && (nchar < minsize)) {
		ASN1err(ASN1_F_ASN1_MBSTRING_COPY, ASN1_R_STRING_TOO_SHORT);
		sprintf(strbuf, "%ld", minsize);
		ERR_add_error_data(2, "minsize=", strbuf);
		return -1;
	}

	if(maxsize && (nchar > maxsize)) {
		ASN1err(ASN1_F_ASN1_MBSTRING_COPY, ASN1_R_STRING_TOO_LONG);
		sprintf(strbuf, "%ld", maxsize);
		ERR_add_error_data(2, "maxsize=", strbuf);
		return -1;
	}

	/* Now work out minimal type (if any) */
	if(traverse_string(in, len, inform, type_str, &mask) < 0) {
		ASN1err(ASN1_F_ASN1_MBSTRING_COPY, ASN1_R_ILLEGAL_CHARACTERS);
		return -1;
	}


	/* Now work out output format and string type */
	outform = MBSTRING_ASC;
	if(mask & B_ASN1_PRINTABLESTRING) str_type = V_ASN1_PRINTABLESTRING;
	else if(mask & B_ASN1_IA5STRING) str_type = V_ASN1_IA5STRING;
	else if(mask & B_ASN1_T61STRING) str_type = V_ASN1_T61STRING;
	else if(mask & B_ASN1_BMPSTRING) {
		str_type = V_ASN1_BMPSTRING;
		outform = MBSTRING_BMP;
	} else if(mask & B_ASN1_UNIVERSALSTRING) {
		str_type = V_ASN1_UNIVERSALSTRING;
		outform = MBSTRING_UNIV;
	} else {
		str_type = V_ASN1_UTF8STRING;
		outform = MBSTRING_UTF8;
	}
	if(!out) return str_type;
	if(*out) {
		dest = *out;
		if(dest->data) {
			dest->length = 0;
			Free(dest->data);
			dest->data = NULL;
		}
		dest->type = str_type;
	} else {
		dest = ASN1_STRING_type_new(str_type);
		if(!dest) {
			ASN1err(ASN1_F_ASN1_MBSTRING_COPY,
							ERR_R_MALLOC_FAILURE);
			return -1;
		}
		*out = dest;
	}
	/* If both the same type just copy across */
	if(inform == outform) {
		if(!ASN1_STRING_set(dest, in, len)) {
			ASN1err(ASN1_F_ASN1_MBSTRING_COPY,ERR_R_MALLOC_FAILURE);
			return -1;
		}
		return str_type;
	} 

	/* Work out how much space the destination will need */
	switch(outform) {
		case MBSTRING_ASC:
		outlen = nchar;
		cpyfunc = cpy_asc;
		break;

		case MBSTRING_BMP:
		outlen = nchar << 1;
		cpyfunc = cpy_bmp;
		break;

		case MBSTRING_UNIV:
		outlen = nchar << 2;
		cpyfunc = cpy_univ;
		break;

		case MBSTRING_UTF8:
		outlen = 0;
		traverse_string(in, len, inform, out_utf8, &outlen);
		cpyfunc = cpy_utf8;
		break;
	}
	if(!(p = Malloc(outlen + 1))) {
		ASN1_STRING_free(dest);
		ASN1err(ASN1_F_ASN1_MBSTRING_COPY,ERR_R_MALLOC_FAILURE);
		return -1;
	}
	dest->length = outlen;
	dest->data = p;
	p[outlen] = 0;
	traverse_string(in, len, inform, cpyfunc, &p);
	return str_type;	
}

/* This function traverses a string and passes the value of each character
 * to an optional function along with a void * argument.
 */

static int traverse_string(const unsigned char *p, int len, int inform,
		 int (*rfunc)(unsigned long value, void *in), void *arg)
{
	unsigned long value;
	int ret;
	while(len) {
		if(inform == MBSTRING_ASC) {
			value = *p++;
			len--;
		} else if(inform == MBSTRING_BMP) {
			value = *p++ << 8;
			value |= *p++;
			len -= 2;
		} else if(inform == MBSTRING_UNIV) {
			value = *p++ << 24;
			value |= *p++ << 16;
			value |= *p++ << 8;
			value |= *p++;
			len -= 4;
		} else {
			ret = UTF8_getc(p, len, &value);
			if(ret < 0) return -1;
			len -= ret;
			p += ret;
		}
		if(rfunc) {
			ret = rfunc(value, arg);
			if(ret <= 0) return ret;
		}
	}
	return 1;
}

/* Various utility functions for traverse_string */

/* Just count number of characters */

static int in_utf8(unsigned long value, void *arg)
{
	int *nchar;
	nchar = arg;
	(*nchar)++;
	return 1;
}

/* Determine size of output as a UTF8 String */

static int out_utf8(unsigned long value, void *arg)
{
	long *outlen;
	outlen = arg;
	*outlen += UTF8_putc(NULL, -1, value);
	return 1;
}

/* Determine the "type" of a string: check each character against a
 * supplied "mask".
 */

static int type_str(unsigned long value, void *arg)
{
	unsigned long types;
	types = *((unsigned long *)arg);
	if((types & B_ASN1_PRINTABLESTRING) && !is_printable(value))
					types &= ~B_ASN1_PRINTABLESTRING;
	if((types & B_ASN1_IA5STRING) && (value > 127))
					types &= ~B_ASN1_IA5STRING;
	if((types & B_ASN1_T61STRING) && (value > 0xff))
					types &= ~B_ASN1_T61STRING;
	if((types & B_ASN1_BMPSTRING) && (value > 0xffff))
					types &= ~B_ASN1_BMPSTRING;
	if(!types) return -1;
	*((unsigned long *)arg) = types;
	return 1;
}

/* Copy one byte per character ASCII like strings */

static int cpy_asc(unsigned long value, void *arg)
{
	unsigned char **p, *q;
	p = arg;
	q = *p;
	*q = (unsigned char) value;
	(*p)++;
	return 1;
}

/* Copy two byte per character BMPStrings */

static int cpy_bmp(unsigned long value, void *arg)
{
	unsigned char **p, *q;
	p = arg;
	q = *p;
	*q++ = (unsigned char) ((value >> 8) & 0xff);
	*q = (unsigned char) (value & 0xff);
	*p += 2;
	return 1;
}

/* Copy four byte per character UniversalStrings */

static int cpy_univ(unsigned long value, void *arg)
{
	unsigned char **p, *q;
	p = arg;
	q = *p;
	*q++ = (unsigned char) ((value >> 24) & 0xff);
	*q++ = (unsigned char) ((value >> 16) & 0xff);
	*q++ = (unsigned char) ((value >> 8) & 0xff);
	*q = (unsigned char) (value & 0xff);
	*p += 4;
	return 1;
}

/* Copy to a UTF8String */

static int cpy_utf8(unsigned long value, void *arg)
{
	unsigned char **p;
	int ret;
	p = arg;
	/* We already know there is enough room so pass 0xff as the length */
	ret = UTF8_putc(*p, 0xff, value);
	*p += ret;
	return 1;
}

/* Return 1 if the character is permitted in a PrintableString */
static int is_printable(unsigned long value)
{
	int ch;
	if(value > 0x7f) return 0;
	ch = (int) value;
	/* Note: we can't use 'isalnum' because certain accented 
	 * characters may count as alphanumeric in some environments.
	 */
	if((ch >= 'a') && (ch <= 'z')) return 1;
	if((ch >= 'A') && (ch <= 'Z')) return 1;
	if((ch >= '0') && (ch <= '9')) return 1;
	if ((ch == ' ') || strchr("'()+,-./:=?", ch)) return 1;
	return 0;
}