boringssl/crypto/asn1/a_strex.c

/* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
 * All rights reserved.
 *
 * This package is an SSL implementation written
 * by Eric Young (eay@cryptsoft.com).
 * The implementation was written so as to conform with Netscapes SSL.
 *
 * This library is free for commercial and non-commercial use as long as
 * the following conditions are aheared to.  The following conditions
 * apply to all code found in this distribution, be it the RC4, RSA,
 * lhash, DES, etc., code; not just the SSL code.  The SSL documentation
 * included with this distribution is covered by the same copyright terms
 * except that the holder is Tim Hudson (tjh@cryptsoft.com).
 *
 * Copyright remains Eric Young's, and as such any Copyright notices in
 * the code are not to be removed.
 * If this package is used in a product, Eric Young should be given attribution
 * as the author of the parts of the library used.
 * This can be in the form of a textual message at program startup or
 * in documentation (online or textual) provided with the package.
 *
 * 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 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 acknowledgement:
 *    "This product includes cryptographic software written by
 *     Eric Young (eay@cryptsoft.com)"
 *    The word 'cryptographic' can be left out if the rouines from the library
 *    being used are not cryptographic related :-).
 * 4. If you include any Windows specific code (or a derivative thereof) from
 *    the apps directory (application code) you must include an acknowledgement:
 *    "This product includes software written by Tim Hudson (tjh@cryptsoft.com)"
 *
 * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
 * ANY EXPRESS 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 AUTHOR OR 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.
 *
 * The licence and distribution terms for any publically available version or
 * derivative of this code cannot be changed.  i.e. this code cannot simply be
 * copied and put under another distribution licence
 * [including the GNU Public Licence.] */

#include <openssl/asn1.h>

#include <inttypes.h>
#include <string.h>

#include <openssl/bio.h>
#include <openssl/mem.h>

#include "charmap.h"
#include "internal.h"


#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)

static int maybe_write(BIO *out, const void *buf, int len)
{
    /* If |out| is NULL, ignore the output but report the length. */
    return out == NULL || BIO_write(out, buf, len) == 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.
 */

#define HEX_SIZE(type) (sizeof(type)*2)

static int do_esc_char(uint32_t c, unsigned char flags, char *do_quotes,
                       BIO *out)
{
    unsigned char chflgs, chtmp;
    char tmphex[HEX_SIZE(uint32_t) + 3];

    if (c > 0xffff) {
        BIO_snprintf(tmphex, sizeof tmphex, "\\W%08" PRIX32, c);
        if (!maybe_write(out, tmphex, 10))
            return -1;
        return 10;
    }
    if (c > 0xff) {
        BIO_snprintf(tmphex, sizeof tmphex, "\\U%04" PRIX32, c);
        if (!maybe_write(out, 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 (!maybe_write(out, &chtmp, 1))
                return -1;
            return 1;
        }
        if (!maybe_write(out, "\\", 1))
            return -1;
        if (!maybe_write(out, &chtmp, 1))
            return -1;
        return 2;
    }
    if (chflgs & (ASN1_STRFLGS_ESC_CTRL | ASN1_STRFLGS_ESC_MSB)) {
        BIO_snprintf(tmphex, 11, "\\%02X", chtmp);
        if (!maybe_write(out, 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 (!maybe_write(out, "\\\\", 2))
            return -1;
        return 2;
    }
    if (!maybe_write(out, &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, BIO *out)
{
    int i, outlen, len, charwidth;
    unsigned char orflags, *p, *q;
    uint32_t c;
    p = buf;
    q = buf + buflen;
    outlen = 0;
    charwidth = type & BUF_TYPE_WIDTH_MASK;

    switch (charwidth) {
    case 4:
        if (buflen & 3) {
            OPENSSL_PUT_ERROR(ASN1, ASN1_R_INVALID_UNIVERSALSTRING);
            return -1;
        }
        break;
    case 2:
        if (buflen & 1) {
            OPENSSL_PUT_ERROR(ASN1, ASN1_R_INVALID_BMPSTRING);
            return -1;
        }
        break;
    default:
        break;
    }

    while (p != q) {
        if (p == buf && flags & ASN1_STRFLGS_ESC_2253)
            orflags = CHARTYPE_FIRST_ESC_2253;
        else
            orflags = 0;
        switch (charwidth) {
        case 4:
            c = ((uint32_t)*p++) << 24;
            c |= ((uint32_t)*p++) << 16;
            c |= ((uint32_t)*p++) << 8;
            c |= *p++;
            break;

        case 2:
            c = ((uint32_t)*p++) << 8;
            c |= *p++;
            break;

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

        case 0:
            i = UTF8_getc(p, buflen, &c);
            if (i < 0)
                return -1;      /* Invalid UTF8String */
            buflen -= i;
            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);
            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, out);
                if (len < 0)
                    return -1;
                outlen += len;
            }
        } else {
            len = do_esc_char(c, (unsigned char)(flags | orflags), quotes, out);
            if (len < 0)
                return -1;
            outlen += len;
        }
    }
    return outlen;
}

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

static int do_hex_dump(BIO *out, unsigned char *buf, int buflen)
{
    static const char hexdig[] = "0123456789ABCDEF";
    unsigned char *p, *q;
    char hextmp[2];
    if (out) {
        p = buf;
        q = buf + buflen;
        while (p != q) {
            hextmp[0] = hexdig[*p >> 4];
            hextmp[1] = hexdig[*p & 0xf];
            if (!maybe_write(out, 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, BIO *out, 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 (!maybe_write(out, "#", 1))
        return -1;
    /* If we don't dump DER encoding just dump content octets */
    if (!(lflags & ASN1_STRFLGS_DUMP_DER)) {
        outlen = do_hex_dump(out, 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 = OPENSSL_malloc(der_len);
    if (!der_buf)
        return -1;
    p = der_buf;
    i2d_ASN1_TYPE(&t, &p);
    outlen = do_hex_dump(out, der_buf, der_len);
    OPENSSL_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.
 */

int ASN1_STRING_print_ex(BIO *out, const ASN1_STRING *str, unsigned long lflags)
{
    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 (!maybe_write(out, tagname, outlen) || !maybe_write(out, ":", 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, out, 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, NULL);
    if (len < 0)
        return -1;
    outlen += len;
    if (quotes)
        outlen += 2;
    if (!out)
        return outlen;
    if (quotes && !maybe_write(out, "\"", 1))
        return -1;
    if (do_buf(str->data, str->length, type, flags, NULL, out) < 0)
        return -1;
    if (quotes && !maybe_write(out, "\"", 1))
        return -1;
    return outlen;
}

int ASN1_STRING_print_ex_fp(FILE *fp, const ASN1_STRING *str,
                            unsigned long flags)
{
    BIO *bio = NULL;
    if (fp != NULL) {
        /* If |fp| is NULL, this function returns the number of bytes without
         * writing. */
        bio = BIO_new_fp(fp, BIO_NOCLOSE);
        if (bio == NULL) {
            return -1;
        }
    }
    int ret = ASN1_STRING_print_ex(bio, str, flags);
    BIO_free(bio);
    return ret;
}

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;
    stmp.flags = 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;
}