UTF8String.c

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/*-
 * Copyright (c) 2003, 2004, 2006 Lev Walkin <vlm@lionet.info>.
 * All rights reserved.
 * Redistribution and modifications are permitted subject to BSD license.
 */
#include <asn_internal.h>
#include <UTF8String.h>

/*
 * UTF8String basic type description.
 */
static ber_tlv_tag_t asn_DEF_UTF8String_tags[] = {
    (ASN_TAG_CLASS_UNIVERSAL | (12 << 2)),  /* [UNIVERSAL 12] IMPLICIT ...*/
    (ASN_TAG_CLASS_UNIVERSAL | (4 << 2)),   /* ... OCTET STRING */
};
asn_TYPE_descriptor_t asn_DEF_UTF8String = {
    "UTF8String",
    "UTF8String",
    OCTET_STRING_free,
    UTF8String_print,
    UTF8String_constraint,      /* Check for invalid codes, etc. */
    OCTET_STRING_decode_ber,    /* Implemented in terms of OCTET STRING */
    OCTET_STRING_encode_der,
    OCTET_STRING_decode_xer_utf8,
    OCTET_STRING_encode_xer_utf8,
    OCTET_STRING_decode_uper,
    OCTET_STRING_encode_uper,
    0, /* Use generic outmost tag fetcher */
    asn_DEF_UTF8String_tags,
    sizeof(asn_DEF_UTF8String_tags)
      / sizeof(asn_DEF_UTF8String_tags[0]) - 1,
    asn_DEF_UTF8String_tags,
    sizeof(asn_DEF_UTF8String_tags)
      / sizeof(asn_DEF_UTF8String_tags[0]),
    0,  /* No PER visible constraints */
    0, 0,   /* No members */
    0   /* No specifics */
};

/*
 * This is the table of length expectations.
 * The second half of this table is only applicable to the long sequences.
 */
static int UTF8String_ht[2][16] = {
    { /* 0x0 ... 0x7 */
      /* 0000..0111 */
      1, 1, 1, 1, 1, 1, 1, 1,
      /* 1000..1011(0), 1100..1101(2), 1110(3), 1111(-1) */
      0, 0, 0, 0, 2, 2, 3, -1 },
    { /* 0xF0 .. 0xF7 */
      /* 11110000..11110111 */
      4, 4, 4, 4, 4, 4, 4, 4,
      5, 5, 5, 5, 6, 6, -1, -1 }
};
static int32_t UTF8String_mv[7] = { 0, 0,
    0x00000080,
    0x00000800,
    0x00010000,
    0x00200000,
    0x04000000
};

/* Internal aliases for return codes */
#define U8E_TRUNC   -1  /* UTF-8 sequence truncated */
#define U8E_ILLSTART    -2  /* Illegal UTF-8 sequence start */
#define U8E_NOTCONT -3  /* Continuation expectation failed */
#define U8E_NOTMIN  -4  /* Not minimal length encoding */
#define U8E_EINVAL  -5  /* Invalid arguments */

int
UTF8String_constraint(asn_TYPE_descriptor_t *td, const void *sptr,
        asn_app_constraint_failed_f *ctfailcb, void *app_key) {
    ssize_t len = UTF8String_length((const UTF8String_t *)sptr);
    switch(len) {
    case U8E_EINVAL:
        _ASN_CTFAIL(app_key, td, sptr,
            "%s: value not given", td->name);
        break;
    case U8E_TRUNC:
        _ASN_CTFAIL(app_key, td, sptr,
            "%s: truncated UTF-8 sequence (%s:%d)",
            td->name, __FILE__, __LINE__);
        break;
    case U8E_ILLSTART:
        _ASN_CTFAIL(app_key, td, sptr,
            "%s: UTF-8 illegal start of encoding (%s:%d)",
            td->name, __FILE__, __LINE__);
        break;
    case U8E_NOTCONT:
        _ASN_CTFAIL(app_key, td, sptr,
            "%s: UTF-8 not continuation (%s:%d)",
            td->name, __FILE__, __LINE__);
        break;
    case U8E_NOTMIN:
        _ASN_CTFAIL(app_key, td, sptr,
            "%s: UTF-8 not minimal sequence (%s:%d)",
            td->name, __FILE__, __LINE__);
        break;
    }
    return (len < 0) ? -1 : 0;
}

static ssize_t
UTF8String__process(const UTF8String_t *st, uint32_t *dst, size_t dstlen) {
    size_t length;
    uint8_t *buf = st->buf;
    uint8_t *end = buf + st->size;
    uint32_t *dstend = dst + dstlen;

    for(length = 0; buf < end; length++) {
        int ch = *buf;
        uint8_t *cend;
        int32_t value;
        int want;

        /* Compute the sequence length */
        want = UTF8String_ht[0][ch >> 4];
        switch(want) {
        case -1:
            /* Second half of the table, long sequence */
            want = UTF8String_ht[1][ch & 0x0F];
            if(want != -1) break;
            /* Fall through */
        case 0:
            return U8E_ILLSTART;
        }

        /* assert(want >= 1 && want <= 6) */

        /* Check character sequence length */
        if(buf + want > end) return U8E_TRUNC;

        value = ch & (0xff >> want);
        cend = buf + want;
        for(buf++; buf < cend; buf++) {
            ch = *buf;
            if(ch < 0x80 || ch > 0xbf) return U8E_NOTCONT;
            value = (value << 6) | (ch & 0x3F);
        }
        if(value < UTF8String_mv[want])
            return U8E_NOTMIN;
        if(dst < dstend)
            *dst++ = value; /* Record value */
    }

    if(dst < dstend) *dst = 0;  /* zero-terminate */

    return length;
}


ssize_t
UTF8String_length(const UTF8String_t *st) {
    if(st && st->buf) {
        return UTF8String__process(st, 0, 0);
    } else {
        return U8E_EINVAL;
    }
}

size_t
UTF8String_to_wcs(const UTF8String_t *st, uint32_t *dst, size_t dstlen) {
    if(st && st->buf) {
        ssize_t ret = UTF8String__process(st, dst, dstlen);
        return (ret < 0) ? 0 : ret;
    } else {
        return 0;
    }
}

int
UTF8String_print(asn_TYPE_descriptor_t *td, const void *sptr, int ilevel,
    asn_app_consume_bytes_f *cb, void *app_key) {
    const UTF8String_t *st = (const UTF8String_t *)sptr;

    (void)td;   /* Unused argument */
    (void)ilevel;   /* Unused argument */

    if(st && st->buf) {
        return (cb(st->buf, st->size, app_key) < 0) ? -1 : 0;
    } else {
        return (cb("<absent>", 8, app_key) < 0) ? -1 : 0;
    }
}