crypto/asn1/a_strex.c

/* $OpenBSD: a_strex.c,v 1.28 2018/05/19 10:46:28 tb Exp $ */
/* Written by Dr Stephen N Henson (steve@openssl.org) for the OpenSSL
 * project 2000.
 */
/* ====================================================================
 * Copyright (c) 2000 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 <string.h>

#include <openssl/asn1.h>
#include <openssl/crypto.h>
#include <openssl/x509.h>

#include "asn1_locl.h"

#include "charmap.h"

/* ASN1_STRING_print_ex() and X509_NAME_print_ex().
 * Enhanced string and name printing routines handling
 * multibyte characters, RFC2253 and a host of other
 * options.
 */

#define CHARTYPE_BS_ESC		(ASN1_STRFLGS_ESC_2253 | CHARTYPE_FIRST_ESC_2253 | CHARTYPE_LAST_ESC_2253)

#define ESC_FLAGS (ASN1_STRFLGS_ESC_2253 | \
		  ASN1_STRFLGS_ESC_QUOTE | \
		  ASN1_STRFLGS_ESC_CTRL | \
		  ASN1_STRFLGS_ESC_MSB)


/* Three IO functions for sending data to memory, a BIO and
 * and a FILE pointer.
 */
static int
send_bio_chars(void *arg, const void *buf, int len)
{
	if (!arg)
		return 1;
	if (BIO_write(arg, buf, len) != len)
		return 0;
	return 1;
}

static int
send_fp_chars(void *arg, const void *buf, int len)
{
	if (!arg)
		return 1;
	if (fwrite(buf, 1, (size_t)len, arg) != (size_t)len)
		return 0;
	return 1;
}

typedef int char_io(void *arg, const void *buf, int len);

/* This function handles display of
 * strings, one character at a time.
 * It is passed an unsigned long for each
 * character because it could come from 2 or even
 * 4 byte forms.
 */

static int
do_esc_char(unsigned long c, unsigned char flags, char *do_quotes,
    char_io *io_ch, void *arg)
{
	unsigned char chflgs, chtmp;
	char tmphex[sizeof(long) * 2 + 3];

	if (c > 0xffffffffL)
		return -1;
	if (c > 0xffff) {
		snprintf(tmphex, sizeof tmphex, "\\W%08lX", c);
		if (!io_ch(arg, tmphex, 10))
			return -1;
		return 10;
	}
	if (c > 0xff) {
		snprintf(tmphex, sizeof tmphex, "\\U%04lX", c);
		if (!io_ch(arg, tmphex, 6))
			return -1;
		return 6;
	}
	chtmp = (unsigned char)c;
	if (chtmp > 0x7f)
		chflgs = flags & ASN1_STRFLGS_ESC_MSB;
	else
		chflgs = char_type[chtmp] & flags;
	if (chflgs & CHARTYPE_BS_ESC) {
		/* If we don't escape with quotes, signal we need quotes */
		if (chflgs & ASN1_STRFLGS_ESC_QUOTE) {
			if (do_quotes)
				*do_quotes = 1;
			if (!io_ch(arg, &chtmp, 1))
				return -1;
			return 1;
		}
		if (!io_ch(arg, "\\", 1))
			return -1;
		if (!io_ch(arg, &chtmp, 1))
			return -1;
		return 2;
	}
	if (chflgs & (ASN1_STRFLGS_ESC_CTRL|ASN1_STRFLGS_ESC_MSB)) {
		snprintf(tmphex, sizeof tmphex, "\\%02X", chtmp);
		if (!io_ch(arg, tmphex, 3))
			return -1;
		return 3;
	}
	/* If we get this far and do any escaping at all must escape
	 * the escape character itself: backslash.
	 */
	if (chtmp == '\\' && flags & ESC_FLAGS) {
		if (!io_ch(arg, "\\\\", 2))
			return -1;
		return 2;
	}
	if (!io_ch(arg, &chtmp, 1))
		return -1;
	return 1;
}

#define BUF_TYPE_WIDTH_MASK	0x7
#define BUF_TYPE_CONVUTF8	0x8

/* This function sends each character in a buffer to
 * do_esc_char(). It interprets the content formats
 * and converts to or from UTF8 as appropriate.
 */

static int
do_buf(unsigned char *buf, int buflen, int type, unsigned char flags,
    char *quotes, char_io *io_ch, void *arg)
{
	int i, outlen, len;
	unsigned char orflags, *p, *q;
	unsigned long c;

	p = buf;
	q = buf + buflen;
	outlen = 0;
	while (p != q) {
		if (p == buf && flags & ASN1_STRFLGS_ESC_2253)
			orflags = CHARTYPE_FIRST_ESC_2253;
		else
			orflags = 0;
		switch (type & BUF_TYPE_WIDTH_MASK) {
		case 4:
			c = ((unsigned long)*p++) << 24;
			c |= ((unsigned long)*p++) << 16;
			c |= ((unsigned long)*p++) << 8;
			c |= *p++;
			if (c > UNICODE_MAX || UNICODE_IS_SURROGATE(c))
				return -1;
			break;

		case 2:
			c = ((unsigned long)*p++) << 8;
			c |= *p++;
			if (UNICODE_IS_SURROGATE(c))
				return -1;
			break;

		case 1:
			c = *p++;
			break;

		case 0:
			i = UTF8_getc(p, q - p, &c);
			if (i < 0)
				return -1;	/* Invalid UTF8String */
			p += i;
			break;
		default:
			return -1;		/* invalid width */
		}
		if (p == q && flags & ASN1_STRFLGS_ESC_2253)
			orflags = CHARTYPE_LAST_ESC_2253;
		if (type & BUF_TYPE_CONVUTF8) {
			unsigned char utfbuf[6];
			int utflen;

			utflen = UTF8_putc(utfbuf, sizeof utfbuf, c);
			if (utflen < 0)
				return -1;
			for (i = 0; i < utflen; i++) {
				/* We don't need to worry about setting orflags correctly
				 * because if utflen==1 its value will be correct anyway
				 * otherwise each character will be > 0x7f and so the
				 * character will never be escaped on first and last.
				 */
				len = do_esc_char(utfbuf[i],
				    (unsigned char)(flags | orflags), quotes,
				    io_ch, arg);
				if (len < 0)
					return -1;
				outlen += len;
			}
		} else {
			len = do_esc_char(c, (unsigned char)(flags | orflags),
			    quotes, io_ch, arg);
			if (len < 0)
				return -1;
			outlen += len;
		}
	}
	return outlen;
}

/* This function hex dumps a buffer of characters */

static int
do_hex_dump(char_io *io_ch, void *arg, unsigned char *buf, int buflen)
{
	static const char hexdig[] = "0123456789ABCDEF";
	unsigned char *p, *q;
	char hextmp[2];
	if (arg) {
		p = buf;
		q = buf + buflen;
		while (p != q) {
			hextmp[0] = hexdig[*p >> 4];
			hextmp[1] = hexdig[*p & 0xf];
			if (!io_ch(arg, hextmp, 2))
				return -1;
			p++;
		}
	}
	return buflen << 1;
}

/* "dump" a string. This is done when the type is unknown,
 * or the flags request it. We can either dump the content
 * octets or the entire DER encoding. This uses the RFC2253
 * #01234 format.
 */

static int
do_dump(unsigned long lflags, char_io *io_ch, void *arg, const ASN1_STRING *str)
{
	/* Placing the ASN1_STRING in a temp ASN1_TYPE allows
	 * the DER encoding to readily obtained
	 */
	ASN1_TYPE t;
	unsigned char *der_buf, *p;
	int outlen, der_len;

	if (!io_ch(arg, "#", 1))
		return -1;
	/* If we don't dump DER encoding just dump content octets */
	if (!(lflags & ASN1_STRFLGS_DUMP_DER)) {
		outlen = do_hex_dump(io_ch, arg, str->data, str->length);
		if (outlen < 0)
			return -1;
		return outlen + 1;
	}
	t.type = str->type;
	t.value.ptr = (char *)str;
	der_len = i2d_ASN1_TYPE(&t, NULL);
	der_buf = malloc(der_len);
	if (!der_buf)
		return -1;
	p = der_buf;
	i2d_ASN1_TYPE(&t, &p);
	outlen = do_hex_dump(io_ch, arg, der_buf, der_len);
	free(der_buf);
	if (outlen < 0)
		return -1;
	return outlen + 1;
}

/* Lookup table to convert tags to character widths,
 * 0 = UTF8 encoded, -1 is used for non string types
 * otherwise it is the number of bytes per character
 */

static const signed char tag2nbyte[] = {
	-1, -1, -1, -1, -1,	/* 0-4 */
	-1, -1, -1, -1, -1,	/* 5-9 */
	-1, -1, 0, -1,		/* 10-13 */
	-1, -1, -1, -1,		/* 15-17 */
	-1, 1, 1,		/* 18-20 */
	-1, 1, 1, 1,		/* 21-24 */
	-1, 1, -1,		/* 25-27 */
	4, -1, 2		/* 28-30 */
};

/* This is the main function, print out an
 * ASN1_STRING taking note of various escape
 * and display options. Returns number of
 * characters written or -1 if an error
 * occurred.
 */

static int
do_print_ex(char_io *io_ch, void *arg, unsigned long lflags,
    const ASN1_STRING *str)
{
	int outlen, len;
	int type;
	char quotes;
	unsigned char flags;

	quotes = 0;
	/* Keep a copy of escape flags */
	flags = (unsigned char)(lflags & ESC_FLAGS);
	type = str->type;
	outlen = 0;

	if (lflags & ASN1_STRFLGS_SHOW_TYPE) {
		const char *tagname;
		tagname = ASN1_tag2str(type);
		outlen += strlen(tagname);
		if (!io_ch(arg, tagname, outlen) || !io_ch(arg, ":", 1))
			return -1;
		outlen++;
	}

	/* Decide what to do with type, either dump content or display it */

	/* Dump everything */
	if (lflags & ASN1_STRFLGS_DUMP_ALL)
		type = -1;
	/* Ignore the string type */
	else if (lflags & ASN1_STRFLGS_IGNORE_TYPE)
		type = 1;
	else {
		/* Else determine width based on type */
		if ((type > 0) && (type < 31))
			type = tag2nbyte[type];
		else
			type = -1;
		if ((type == -1) && !(lflags & ASN1_STRFLGS_DUMP_UNKNOWN))
			type = 1;
	}

	if (type == -1) {
		len = do_dump(lflags, io_ch, arg, str);
		if (len < 0)
			return -1;
		outlen += len;
		return outlen;
	}

	if (lflags & ASN1_STRFLGS_UTF8_CONVERT) {
		/* Note: if string is UTF8 and we want
		 * to convert to UTF8 then we just interpret
		 * it as 1 byte per character to avoid converting
		 * twice.
		 */
		if (!type)
			type = 1;
		else
			type |= BUF_TYPE_CONVUTF8;
	}

	len = do_buf(str->data, str->length, type, flags, &quotes, io_ch, NULL);
	if (len < 0)
		return -1;
	outlen += len;
	if (quotes)
		outlen += 2;
	if (!arg)
		return outlen;
	if (quotes && !io_ch(arg, "\"", 1))
		return -1;
	if (do_buf(str->data, str->length, type, flags, NULL, io_ch, arg) < 0)
		return -1;
	if (quotes && !io_ch(arg, "\"", 1))
		return -1;
	return outlen;
}

/* Used for line indenting: print 'indent' spaces */

static int
do_indent(char_io *io_ch, void *arg, int indent)
{
	int i;
	for (i = 0; i < indent; i++)
		if (!io_ch(arg, " ", 1))
			return 0;
	return 1;
}

#define FN_WIDTH_LN	25
#define FN_WIDTH_SN	10

static int
do_name_ex(char_io *io_ch, void *arg, const X509_NAME *n, int indent,
    unsigned long flags)
{
	int i, prev = -1, orflags, cnt;
	int fn_opt, fn_nid;
	ASN1_OBJECT *fn;
	ASN1_STRING *val;
	X509_NAME_ENTRY *ent;
	char objtmp[80];
	const char *objbuf;
	int outlen, len;
	char *sep_dn, *sep_mv, *sep_eq;
	int sep_dn_len, sep_mv_len, sep_eq_len;

	if (indent < 0)
		indent = 0;
	outlen = indent;
	if (!do_indent(io_ch, arg, indent))
		return -1;

	switch (flags & XN_FLAG_SEP_MASK) {
	case XN_FLAG_SEP_MULTILINE:
		sep_dn = "\n";
		sep_dn_len = 1;
		sep_mv = " + ";
		sep_mv_len = 3;
		break;

	case XN_FLAG_SEP_COMMA_PLUS:
		sep_dn = ",";
		sep_dn_len = 1;
		sep_mv = "+";
		sep_mv_len = 1;
		indent = 0;
		break;

	case XN_FLAG_SEP_CPLUS_SPC:
		sep_dn = ", ";
		sep_dn_len = 2;
		sep_mv = " + ";
		sep_mv_len = 3;
		indent = 0;
		break;

	case XN_FLAG_SEP_SPLUS_SPC:
		sep_dn = "; ";
		sep_dn_len = 2;
		sep_mv = " + ";
		sep_mv_len = 3;
		indent = 0;
		break;

	default:
		return -1;
	}

	if (flags & XN_FLAG_SPC_EQ) {
		sep_eq = " = ";
		sep_eq_len = 3;
	} else {
		sep_eq = "=";
		sep_eq_len = 1;
	}

	fn_opt = flags & XN_FLAG_FN_MASK;

	cnt = X509_NAME_entry_count(n);
	for (i = 0; i < cnt; i++) {
		if (flags & XN_FLAG_DN_REV)
			ent = X509_NAME_get_entry(n, cnt - i - 1);
		else
			ent = X509_NAME_get_entry(n, i);
		if (prev != -1) {
			if (prev == ent->set) {
				if (!io_ch(arg, sep_mv, sep_mv_len))
					return -1;
				outlen += sep_mv_len;
			} else {
				if (!io_ch(arg, sep_dn, sep_dn_len))
					return -1;
				outlen += sep_dn_len;
				if (!do_indent(io_ch, arg, indent))
					return -1;
				outlen += indent;
			}
		}
		prev = ent->set;
		fn = X509_NAME_ENTRY_get_object(ent);
		val = X509_NAME_ENTRY_get_data(ent);
		fn_nid = OBJ_obj2nid(fn);
		if (fn_opt != XN_FLAG_FN_NONE) {
			int objlen, fld_len;
			if ((fn_opt == XN_FLAG_FN_OID) ||
			    (fn_nid == NID_undef)) {
				OBJ_obj2txt(objtmp, sizeof objtmp, fn, 1);
				fld_len = 0; /* XXX: what should this be? */
				objbuf = objtmp;
			} else {
				if (fn_opt == XN_FLAG_FN_SN) {
					fld_len = FN_WIDTH_SN;
					objbuf = OBJ_nid2sn(fn_nid);
				} else if (fn_opt == XN_FLAG_FN_LN) {
					fld_len = FN_WIDTH_LN;
					objbuf = OBJ_nid2ln(fn_nid);
				} else {
					fld_len = 0; /* XXX: what should this be? */
					objbuf = "";
				}
			}
			objlen = strlen(objbuf);
			if (!io_ch(arg, objbuf, objlen))
				return -1;
			if ((objlen < fld_len) && (flags & XN_FLAG_FN_ALIGN)) {
				if (!do_indent(io_ch, arg, fld_len - objlen))
					return -1;
				outlen += fld_len - objlen;
			}
			if (!io_ch(arg, sep_eq, sep_eq_len))
				return -1;
			outlen += objlen + sep_eq_len;
		}
		/* If the field name is unknown then fix up the DER dump
		 * flag. We might want to limit this further so it will
 		 * DER dump on anything other than a few 'standard' fields.
		 */
		if ((fn_nid == NID_undef) &&
		    (flags & XN_FLAG_DUMP_UNKNOWN_FIELDS))
			orflags = ASN1_STRFLGS_DUMP_ALL;
		else
			orflags = 0;

		len = do_print_ex(io_ch, arg, flags | orflags, val);
		if (len < 0)
			return -1;
		outlen += len;
	}
	return outlen;
}

/* Wrappers round the main functions */

int
X509_NAME_print_ex(BIO *out, const X509_NAME *nm, int indent,
    unsigned long flags)
{
	if (flags == XN_FLAG_COMPAT)
		return X509_NAME_print(out, nm, indent);
	return do_name_ex(send_bio_chars, out, nm, indent, flags);
}

int
X509_NAME_print_ex_fp(FILE *fp, const X509_NAME *nm, int indent,
    unsigned long flags)
{
	if (flags == XN_FLAG_COMPAT) {
		BIO *btmp;
		int ret;
		btmp = BIO_new_fp(fp, BIO_NOCLOSE);
		if (!btmp)
			return -1;
		ret = X509_NAME_print(btmp, nm, indent);
		BIO_free(btmp);
		return ret;
	}
	return do_name_ex(send_fp_chars, fp, nm, indent, flags);
}

int
ASN1_STRING_print_ex(BIO *out, const ASN1_STRING *str, unsigned long flags)
{
	return do_print_ex(send_bio_chars, out, flags, str);
}

int
ASN1_STRING_print_ex_fp(FILE *fp, const ASN1_STRING *str, unsigned long flags)
{
	return do_print_ex(send_fp_chars, fp, flags, str);
}

/* Utility function: convert any string type to UTF8, returns number of bytes
 * in output string or a negative error code
 */

int
ASN1_STRING_to_UTF8(unsigned char **out, const ASN1_STRING *in)
{
	ASN1_STRING stmp, *str = &stmp;
	int mbflag, type, ret;

	if (!in)
		return -1;
	type = in->type;
	if ((type < 0) || (type > 30))
		return -1;
	mbflag = tag2nbyte[type];
	if (mbflag == -1)
		return -1;
	mbflag |= MBSTRING_FLAG;
	stmp.data = NULL;
	stmp.length = 0;
	ret = ASN1_mbstring_copy(&str, in->data, in->length, mbflag,
	    B_ASN1_UTF8STRING);
	if (ret < 0)
		return ret;
	*out = stmp.data;
	return stmp.length;
}