clamav/libclamav/asn1.c

#include "asn1.h"
#include "others.h"
#include "bignum.h"


int asn1_get_obj(fmap_t *map, void *asn1data, unsigned int *asn1len, struct cli_asn1 *obj) {
    unsigned int asn1_sz = *asn1len;
    unsigned int readbytes = MIN(6, asn1_sz), i;
    uint8_t *data;

    if(asn1_sz < 2) {
	cli_dbgmsg("asn1_get_obj: insufficient data length\n");
	return 1;
    }
    data = fmap_need_ptr_once(map, asn1data, readbytes);
    if(!data) {
	cli_dbgmsg("asn1_get_obj: obj out of file\n");
	return 1;
    }

    obj->type = data[0];
    i = data[1];
    data+=2;
    if(i & 0x80) {
	if(i == 0x80) {
	    /* FIXME: double NULL terminated */
	    cli_dbgmsg("asn1_get_obj: unsupported indefinite length object\n");
	    return 1;
	}
	i &= ~0x80;
	if(i > readbytes - 2) {
	    cli_dbgmsg("asn1_get_obj: len octets overflow (or just too many)\n");
	    return 1;
	}
	obj->size = 0;
	while(i--) {
	    obj->size <<= 8;
	    obj->size |= *data;
	    data ++;
	}
    } else
	obj->size = i;

    asn1_sz -= data - (uint8_t *)asn1data;
    if(obj->size > asn1_sz) {
	cli_dbgmsg("asn1_get_obj: content overflow\n");
	return 1;
    }

    obj->content = data;
    if(obj->size == asn1_sz)
	obj->next = NULL;
    else
	obj->next = data + obj->size;
    *asn1len = asn1_sz - obj->size;
    return 0;
}

int asn1_expect_objtype(fmap_t *map, void *asn1data, unsigned int *asn1len, struct cli_asn1 *obj, uint8_t type) {
    int ret = asn1_get_obj(map, asn1data, asn1len, obj);
    if(ret)
	return ret;
    if(obj->type != type) {
	cli_dbgmsg("asn1_expect_objtype: expected type %02x, got %02x\n", type, obj->type);
	return 1;
    }
    return 0;
}

int asn1_expect_obj(fmap_t *map, void *asn1data, unsigned int *asn1len, struct cli_asn1 *obj, uint8_t type, unsigned int size, const void *content) {
    int ret = asn1_expect_objtype(map, asn1data, asn1len, obj, type);
    if(ret)
	return ret;
    if(obj->size != size) {
	cli_dbgmsg("asn1_expect_obj: expected size %u, got %u\n", size, obj->size);
	return 1;
    }
    if(size) {
	if(!fmap_need_ptr_once(map, obj->content, size)) {
	    cli_dbgmsg("asn1_expect_obj: failed to read content\n");
	    return 1;
	}
	if(memcmp(obj->content, content, size)) {
	    cli_dbgmsg("asn1_expect_obj: content mismatch\n");
	    return 1;
	}
    }
    return 0;
}

int asn1_expect_algo(fmap_t *map, void **asn1data, unsigned int *asn1len, unsigned int algo_size, const void *algo) {
    struct cli_asn1 obj;
    unsigned int avail;
    int ret;
    if((ret = asn1_expect_objtype(map, *asn1data, asn1len, &obj, 0x30))) /* SEQUENCE */
	return ret;
    avail = obj.size;
    *asn1data = obj.next;

    if((ret = asn1_expect_obj(map, obj.content, &avail, &obj, 0x06, algo_size, algo))) /* ALGO */
	return ret;
    if((ret = asn1_expect_obj(map, obj.next, &avail, &obj, 0x05, 0, NULL))) /* NULL */
	return ret;
    if(avail) {
	cli_dbgmsg("asn1_expect_algo: extra data found in SEQUENCE\n");
	return 1;
    }
    return 0;
}


int asn1_expect_rsa(fmap_t *map, void **asn1data, unsigned int *asn1len) {
    struct cli_asn1 obj;
    unsigned int avail;
    int ret;
    if((ret = asn1_expect_objtype(map, *asn1data, asn1len, &obj, 0x30))) /* SEQUENCE */
	return ret;
    avail = obj.size;
    *asn1data = obj.next;

    if(asn1_get_obj(map, obj.content, &avail, &obj))
	return 1;
    if(obj.type != 0x06 || (obj.size != 5 && obj.size != 9)) {
	cli_dbgmsg("asn1_expect_rsa: expecting OID with size 5 or 9, got %02x with size %u\n", obj.type, obj.size);
	return 1;
    }
    if(!fmap_need_ptr_once(map, obj.content, obj.size)) {
	cli_dbgmsg("asn1_expect_rsa: failed to read OID\n");
	return 1;
    }

    if((obj.size == 5 && memcmp(obj.content, "\x2b\x0e\x03\x02\x1d", 5)) || (obj.size == 9 && memcmp(obj.content, "\x2a\x86\x48\x86\xf7\x0d\x01\x01\x05", 9) && memcmp(obj.content, "\x2a\x86\x48\x86\xf7\x0d\x01\x01\x04", 9))) {
	cli_dbgmsg("asn1_expect_rsa: OID mismatch\n");
	return 1;
    }
    if((ret = asn1_expect_obj(map, obj.next, &avail, &obj, 0x05, 0, NULL))) /* NULL */
	return ret;
    if(avail) {
	cli_dbgmsg("asn1_expect_rsa: extra data found in SEQUENCE\n");
	return 1;
    }
    return 0;
}

int ms_asn1_get_sha1(fmap_t *map, void *asn1data, unsigned int avail, unsigned int emb, uint8_t sha1[SHA1_HASH_SIZE], unsigned int *type) {
    /* ret
     * 0 - success
     * 1 - unexpected obj (ok for cat)
     * 2 - severe
     */
    struct cli_asn1 obj, obj2;
    unsigned int avail2;

    /* Manual parsing to avoid spamming */
    if(asn1_expect_objtype(map, asn1data, &avail, &obj, 0x06))
	return 2;
    if(obj.size != 10)
	return 1;
    if(!fmap_need_ptr_once(map, obj.content, 10)) {
	cli_dbgmsg("ms_asn1_get_sha1: failed to read content\n");
	return 2;
    }
    if(memcmp(obj.content, "\x2b\x06\x01\x04\x01\x82\x37\x02\x01\x04", 10)) /* OBJECT 1.3.6.1.4.1.311.2.1.4 - SPC_INDIRECT_DATA_OBJID */
	return 1;

    if(asn1_expect_objtype(map, obj.next, &avail, &obj, emb ? 0xa0 : 0x31))
	return 2;

    avail = obj.size;
    if(asn1_expect_objtype(map, obj.content, &avail, &obj, 0x30)) /* SEQUENCE */
	return 2;

    avail = obj.size;
    if(asn1_get_obj(map, obj.content, &avail, &obj)) /* data - contains an objid 1.3.6.1.4.1.311.2.1.15 or 1.3.6.1.4.1.311.2.1.25 */
	return 2;
    avail2 = obj.size;
    if(asn1_expect_objtype(map, obj.content, &avail2, &obj2, 0x06)) /* OBJECT */
	return 2;
    if(obj2.size != 10) {
	cli_dbgmsg("ms_asn1_get_sha1: expected data object size 10, got %u\n", obj2.size);
	return 2;
    }
    if(!fmap_need_ptr_once(map, obj2.content, 10)) {
	cli_dbgmsg("ms_asn1_get_sha1: failed to read data content\n");
	return 2;
    }
    if(!memcmp(obj2.content, "\x2b\x06\x01\x04\x01\x82\x37\x02\x01\x0f", 10)) {
	/* SPC_PE_IMAGE_DATA_OBJID */
	if(type) *type = 1;
    } else if (!emb && !memcmp(obj2.content, "\x2b\x06\x01\x04\x01\x82\x37\x02\x01\x19", 10)) {
	/* SPC_CAB_DATA_OBJID */
	if(type) *type = 0;
    } else {
	cli_dbgmsg("ms_asn1_get_sha1: data object id mismatch\n");
	return 2;
    }

    if(asn1_expect_objtype(map, obj.next, &avail, &obj, 0x30)) /* messageDigest */
	return 2;

    avail = obj.size;
    if(asn1_expect_algo(map, &obj.content, &avail, 5, "\x2b\x0e\x03\x02\x1a")) /* objid 1.3.14.3.2.26 - sha1 */
       return 2;

    if(asn1_expect_objtype(map, obj.content, &avail, &obj, 0x04))
	return 2;
    if(avail) {
	cli_dbgmsg("ms_asn1_get_sha1: found unexpected extra data\n");
	return 2;
    }
    if(obj.size != SHA1_HASH_SIZE) {
	cli_dbgmsg("ms_asn1_get_sha1: expected sha1 lenght(%u), but got %u\n", SHA1_HASH_SIZE, obj.size);
	return 2;
    }

    if(!fmap_need_ptr_once(map, obj.content, SHA1_HASH_SIZE)) {
	cli_dbgmsg("ms_asn1_get_sha1: failed to read sha1 content\n");
	return 2;
    }
    memcpy(sha1, obj.content, SHA1_HASH_SIZE);

    return 0;
}

static int asn1_getnum(const char *s) {
    if(s[0] < '0' || s[0] >'9' || s[1] < '0' || s[1] > '9') {
	cli_dbgmsg("asn1_getnum: expecting digits, found '%c%c'\n", s[0], s[1]);
	return -1;
    }
    return (s[0] - '0')*10 + (s[1] - '0');
}

int asn1_get_time(fmap_t *map, void **asn1data, unsigned int *size, time_t *time) {
    struct cli_asn1 obj;
    int ret = asn1_get_obj(map, *asn1data, size, &obj);
    unsigned int len;
    char *ptr;
    struct tm t;
    int n;

    if(ret)
	return ret;

    if(obj.type == 0x17) /* UTCTime - YYMMDDHHMMSSZ */
	len = 13;
    else if(obj.type == 0x18) /* GeneralizedTime - YYYYMMDDHHMMSSZ */
	len = 15;
    else {
	cli_dbgmsg("asn1_get_time: expected UTCTime or GeneralizedTime, got %02x\n", obj.type);
	return 1;
    }

    if(!fmap_need_ptr_once(map, obj.content, len)) {
	cli_dbgmsg("asn1_get_time: failed to read content\n");
	return 1;
    }

    memset(&t, 0, sizeof(t));
    ptr = (char *)obj.content;
    if(obj.type == 0x18) {
	t.tm_year = asn1_getnum(ptr) * 100;
	if(t.tm_year < 0)
	    return 1;
	n = asn1_getnum(ptr);
	if(n<0)
	    return 1;
	t.tm_year += n;
	ptr+=4;
    } else {
	n = asn1_getnum(ptr);
	if(n<0)
	    return 1;
	if(n>=50)
	    t.tm_year = 1900 + n;
	else
	    t.tm_year = 2000 + n;
	ptr += 2;
    }
    n = asn1_getnum(ptr);
    if(n<1 || n>12) {
	cli_dbgmsg("asn1_get_time: invalid month %u\n", n);
	return 1;
    }
    t.tm_mon = n;
    ptr+=2;

    n = asn1_getnum(ptr);
    if(n<1 || n>31) {
	cli_dbgmsg("asn1_get_time: invalid day %u\n", n);
	return 1;
    }
    t.tm_mday = n;
    ptr+=2;

    n = asn1_getnum(ptr);
    if(n<0 || n>23) {
	cli_dbgmsg("asn1_get_time: invalid hour %u\n", n);
	return 1;
    }
    t.tm_hour = n;
    ptr+=2;

    n = asn1_getnum(ptr);
    if(n<0 || n>59) {
	cli_dbgmsg("asn1_get_time: invalid minute %u\n", n);
	return 1;
    }
    t.tm_min = n;
    ptr+=2;

    n = asn1_getnum(ptr);
    if(n<0 || n>59) {
	cli_dbgmsg("asn1_get_time: invalid second %u\n", n);
	return 1;
    }
    t.tm_sec = n;
    ptr+=2;

    if(*ptr != 'Z') {
	cli_dbgmsg("asn1_get_time: expected UTC time 'Z', got '%c'\n", *ptr);
	return 1;
    }

    *time = mktime(&t);
    *asn1data = obj.next;
    return 0;
}

int asn1_get_rsa_pubkey(fmap_t *map, void **asn1data, unsigned int *size) {
    struct cli_asn1 obj;
    unsigned int avail, avail2;
    mp_int n, e;

    if(asn1_expect_objtype(map, *asn1data, size, &obj, 0x30)) /* subjectPublicKeyInfo */
	return 1;
    *asn1data = obj.next;

    avail = obj.size;
    if(asn1_expect_algo(map, &obj.content, &avail, 9, "\x2a\x86\x48\x86\xf7\x0d\x01\x01\x01")) /* rsaEncryption */
       return 1;

    if(asn1_expect_objtype(map, obj.content, &avail, &obj, 0x03)) /* BIT STRING - subjectPublicKey */
	return 1;
    if(avail) {
	cli_dbgmsg("asn1_get_rsa_pubkey: found unexpected extra data in subjectPublicKeyInfo\n");
	return 1;
    }
    /* if(obj.size != 141 && obj.size != 271) /\* encoded len of 1024 and 2048 bit public keys *\/ */
    /*	return 1; */

    if(!fmap_need_ptr_once(map, obj.content, 1)) {
	cli_dbgmsg("asn1_get_rsa_pubkey: cannot read public key content\n");
	return 1;
    }
    if(((uint8_t *)obj.content)[0] != 0) { /* no byte fragments */
	cli_dbgmsg("asn1_get_rsa_pubkey: unexpected byte frags in public key\n");
	return 1;
    }

    avail = obj.size - 1;
    obj.content = ((uint8_t *)obj.content) + 1;
    if(asn1_expect_objtype(map, obj.content, &avail, &obj, 0x30)) /* SEQUENCE */
	return 1;
    if(avail) {
	cli_dbgmsg("asn1_get_rsa_pubkey: found unexpected extra data in public key content\n");
	return 1;
    }

    avail = obj.size;
    if(asn1_expect_objtype(map, obj.content, &avail, &obj, 0x02)) /* INTEGER - mod */
	return 1;
    if(obj.size < 1024/8 || obj.size > 4096/8+1) {
	cli_dbgmsg("asn1_get_rsa_pubkey: modulus has got an unsupported length (%u)\n",  obj.size * 8);
	return 1;
    }
    avail2 = obj.size;
    if(!fmap_need_ptr_once(map, obj.content, avail2)) {
	cli_dbgmsg("asn1_get_rsa_pubkey: cannot read n\n");
	return 1;
    }
    if(mp_init(&n) || mp_read_signed_bin(&n, obj.content, avail2)) {
	cli_dbgmsg("asn1_get_rsa_pubkey: cannot convert n to big number\n");
	return 1;
    }

    if(asn1_expect_objtype(map, obj.next, &avail, &obj, 0x02)) /* INTEGER - exp */
	return 1;
    if(avail) {
	cli_dbgmsg("asn1_get_rsa_pubkey: found unexpected extra data after exp\n");
	return 1;
    }
    if(obj.size < 1 || obj.size > avail2) {
	cli_dbgmsg("asn1_get_rsa_pubkey: exponent has got an unsupported length (%u)\n",  obj.size * 8);
	return 1;
    }
    if(!fmap_need_ptr_once(map, obj.content, obj.size)) {
	cli_dbgmsg("asn1_get_rsa_pubkey: cannot read e\n");
	return 1;
    }
    if(mp_init(&e) || mp_read_signed_bin(&n, obj.content, obj.size)) {
	cli_dbgmsg("asn1_get_rsa_pubkey: cannot convert e to big number\n");
	return 1;
    }
    return 0;
}

int asn1_get_x509(fmap_t *map, void **asn1data, unsigned int *size) {
    struct cli_asn1 crt, tbs, obj;
    unsigned int avail;
    time_t not_before, not_after;
    void *next;

    if(asn1_expect_objtype(map, *asn1data, size, &crt, 0x30)) /* SEQUENCE */
	return 1;

    if(asn1_expect_objtype(map, crt.content, &crt.size, &tbs, 0x30)) /* SEQUENCE - TBSCertificate */
	return 1;

    if(asn1_expect_objtype(map, tbs.content, &tbs.size, &obj, 0xa0)) /* [0] */
	return 1;
    avail = obj.size;
    next = obj.next;
    if(asn1_expect_obj(map, obj.content, &avail, &obj, 0x02, 1, "\x02")) /* version 3 only */
	return 1;
    if(avail) {
	cli_dbgmsg("asn1_get_x509: found unexpected extra data in version\n");
	return 1;
    }

    if(asn1_expect_objtype(map, next, &tbs.size, &obj, 0x02)) /* serialNumber */
	return 1;

    if(asn1_expect_rsa(map, &obj.next, &tbs.size)) /* algo = sha1WithRSAEncryption | md5WithRSAEncryption */
       return 1;

    if(asn1_expect_objtype(map, obj.next, &tbs.size, &obj, 0x30)) /* issuer */
	return 1;

    if(asn1_expect_objtype(map, obj.next, &tbs.size, &obj, 0x30)) /* validity */
	return 1;
    avail = obj.size;
    next = obj.content;
    if(asn1_get_time(map, &next, &avail, &not_before)) /* notBefore */
	return 1;
    if(asn1_get_time(map, &next, &avail, &not_after)) /* notAfter */
	return 1;
    if(avail) {
	cli_dbgmsg("asn1_get_x509: found unexpected extra data in validity\n");
	return 1;
    }

    if(asn1_expect_objtype(map, obj.next, &tbs.size, &obj, 0x30)) /* subject */
	return 1;

    if(asn1_get_rsa_pubkey(map, &obj.next, &tbs.size))
       return 1;

    avail = 0;
    while(tbs.size) {
	/* extensions */
	if(asn1_get_obj(map, obj.next, &tbs.size, &obj))
	    return 1;
	if(obj.type <= 0xa0 + avail || obj.type > 0xa3) {
	    cli_dbgmsg("asn1_get_x509: found type %02x in extensions, expecting a1, a2 or a3\n", obj.type);
	    return 1;
	}
	avail = obj.type - 0xa0;
    }

    if(asn1_expect_rsa(map, &tbs.next, &crt.size)) /* signature algo = sha1WithRSAEncryption | md5WithRSAEncryption */
       return 1;

    if(asn1_expect_objtype(map, tbs.next, &crt.size, &obj, 0x03)) /* signature */
	return 1;
    if(crt.size) {
	cli_dbgmsg("asn1_get_x509: found unexpected extra data in signature\n");
	return 1;
    }

    *asn1data = crt.next;
    return 0;
}








int asn1_parse_mscat(FILE *f) {
    struct cli_asn1 asn1, deep, deeper;
    unsigned int size, dsize;
    fmap_t *map;
    void *next;

    cli_dbgmsg("in asn1_parse_mscat\n");
    if(!(map = fmap(fileno(f), 0, 0)))
	return 1;

    do {
	if(!(next = fmap_need_off_once(map, 0, 1))) {
	    cli_dbgmsg("asn1_parse_mscat: failed to read cat\n");
	    break;
	}
	size = map->len;
	if(asn1_expect_objtype(map, next, &size, &asn1, 0x30)) /* SEQUENCE */
	    break;
	if(size) {
	    cli_dbgmsg("asn1_parse_mscat: found extra data after pkcs#7\n");
	    break;
	}
	size = asn1.size;
	if(asn1_expect_obj(map, asn1.content, &size, &asn1, 0x06, 9, "\x2a\x86\x48\x86\xf7\x0d\x01\x07\x02")) /* OBJECT 1.2.840.113549.1.7.2 - contentType = signedData */
	    break;
	if(asn1_expect_objtype(map, asn1.next, &size, &asn1, 0xa0)) /* [0] - content */
	    break;
	if(size) {
	    cli_dbgmsg("asn1_parse_mscat: found extra data in pkcs#7\n");
	    break;
	}
	size = asn1.size;
	if(asn1_expect_objtype(map, asn1.content, &size, &asn1, 0x30)) /* SEQUENCE */
	    break;
	if(size) {
	    cli_dbgmsg("asn1_parse_mscat: found extra data in signedData\n");
	    break;
	}
	size = asn1.size;
	if(asn1_expect_obj(map, asn1.content, &size, &asn1, 0x02, 1, "\x01")) /* INTEGER - VERSION 1 */
	    break;

	if(asn1_expect_objtype(map, asn1.next, &size, &asn1, 0x31)) /* SET OF DigestAlgorithmIdentifier */
	    break;

	if(asn1_expect_algo(map, &asn1.content, &asn1.size, 5, "\x2b\x0e\x03\x02\x1a")) /* DigestAlgorithmIdentifier[0] == sha1 */
	    break;
	if(asn1.size) {
	    cli_dbgmsg("asn1_parse_mscat: only one digestAlgorithmIdentifier is allowed\n");
	    break;
	}

	if(asn1_expect_objtype(map, asn1.next, &size, &asn1, 0x30)) /* SEQUENCE - contentInfo */
	    break;
	/* Here there is either a PKCS #7 ContentType Object Identifier for Certificate Trust List (szOID_CTL)
	 * or a single SPC_INDIRECT_DATA_OBJID */
	if(asn1_expect_obj(map, asn1.content, &asn1.size, &deep, 0x06, 9, "\x2b\x06\x01\x04\x01\x82\x37\x0a\x01")) /* szOID_CTL - 1.3.6.1.4.1.311.10.1 */
	    break;
	if(asn1_expect_objtype(map, deep.next, &asn1.size, &deep, 0xa0))
	    break;
	if(asn1.size) {
	    cli_dbgmsg("asn1_parse_mscat: found extra data in szOID_CTL\n");
	    break;
	}
	dsize = deep.size;
	if(asn1_expect_objtype(map, deep.content, &dsize, &deep, 0x30))
	    break;
	if(dsize) {
	    cli_dbgmsg("asn1_parse_mscat: found extra data in szOID_CTL content\n");
	    break;
	}

	dsize = deep.size;
	if(asn1_expect_objtype(map, deep.content, &dsize, &deep, 0x30))
	    break;
	if(asn1_expect_obj(map, deep.content, &deep.size, &deeper, 0x06, 10, "\x2b\x06\x01\x04\x01\x82\x37\x0c\x01\x01")) /* szOID_CATALOG_LIST - 1.3.6.1.4.1.311.12.1.1 */
	    break;
	if(deep.size) {
	    cli_dbgmsg("asn1_parse_mscat: found extra data in szOID_CATALOG_LIST content\n");
	    break;
	}
	if(asn1_expect_objtype(map, deep.next, &dsize, &deep, 0x4)) /* List ID */
	    break;
	if(asn1_expect_objtype(map, deep.next, &dsize, &deep, 0x17)) /* Effective date - WTF?! */
	    break;
	if(asn1_expect_algo(map, &deep.next, &dsize, 10, "\x2b\x06\x01\x04\x01\x82\x37\x0c\x01\x02")) /* szOID_CATALOG_LIST_MEMBER */
	    break;
	if(asn1_expect_objtype(map, deep.next, &dsize, &deep, 0x30)) /* hashes here */
	    break;
	while(deep.size) {
	    struct cli_asn1 tag;
	    if(asn1_expect_objtype(map, deep.content, &deep.size, &deeper, 0x30)) {
		deep.size = 1;
		break;
	    }
	    deep.content = deeper.next;
	    if(asn1_expect_objtype(map, deeper.content, &deeper.size, &tag, 0x04)) { /* TAG NAME */
		deep.size = 1;
		break;
	    }
	    if(asn1_expect_objtype(map, tag.next, &deeper.size, &tag, 0x31)) { /* set */
		deep.size = 1;
		break;
	    }
	    if(deeper.size) {
		cli_dbgmsg("asn1_parse_mscat: found extra data in tag\n");
		deep.size = 1;
		break;
	    }
	    while(tag.size) {
		struct cli_asn1 tagval;
		unsigned int tsize, tsize2, hashtype;
		uint8_t sha1[SHA1_HASH_SIZE];
		void *tagc;
		int i;

		if(asn1_expect_objtype(map, tag.content, &tag.size, &tagval, 0x30)) {
		    tag.size = 1;
		    break;
		}
		tag.content = tagval.next;
		tsize = tsize2 = tagval.size;
		tagc = tagval.content;
		if(asn1_expect_objtype(map, tagval.content, &tsize, &tagval, 0x06)) {
		    tag.size = 1;
		    break;
		}
		i = ms_asn1_get_sha1(map, tagc, tsize2, 0, sha1, &hashtype);
		if(!i) {
		    char sha1txt[SHA1_HASH_SIZE*2+1];

		    for(i=0;i<SHA1_HASH_SIZE; i++)
			sprintf(&sha1txt[i*2], "%02x", sha1[i]);
		    cli_dbgmsg("asn1_parse_cat: found hash %s (type %s)\n", sha1txt, hashtype ? "PE" : "CAB");
		} else if(i==1){
		    /* expect to hit here on CAT_NAMEVALUE_OBJID(1.3.6.1.4.1.311.12.2.1) and CAT_MEMBERINFO_OBJID(.2) */
		} else {
		    tag.size = 1;
		    cli_dbgmsg("asn1_parse_mscat: bad field in tag value\n");
		    break;
		}
		if(asn1_expect_objtype(map, tagval.next, &tsize, &tagval, 0x31)) {
		    tag.size = 1;
		    break;
		}
		if(tsize) {
		    tag.size = 1;
		    cli_dbgmsg("asn1_parse_mscat: extra data in value\n");
		    break;
		}
	    }
	    if(tag.size) {
		deep.size = 1;
		break;
	    }
	}
	if(deep.size)
	    break;

	if(asn1_expect_objtype(map, asn1.next, &size, &asn1, 0xa0)) /* certificates */
	    break;

	dsize = asn1.size;
	while(dsize) {
	    if(asn1_get_x509(map, &asn1.content, &dsize)) {
		dsize = 1;
		break;
	    }
	}
	if(dsize)
	    break;

	if(asn1_get_obj(map, asn1.next, &size, &asn1))
	    break;
	if(asn1.type == 0xa1 && asn1_get_obj(map, asn1.next, &size, &asn1)) /* crls - unused shouldn't be present */
	    break;
	if(asn1.type != 0x31) { /* signerInfos */
	    cli_dbgmsg("asn1_parse_mscat: unexpected type %02x for signerInfos\n", asn1.type);
	    break;
	}
	if(size) {
	    cli_dbgmsg("asn1_parse_mscat: unexpected extra data after signerInfos\n");
	    break;
	}
	size = asn1.size;
	if(asn1_expect_objtype(map, asn1.content, &size, &asn1, 0x30))
	    break;
	if(size) {
	    cli_dbgmsg("asn1_parse_mscat: only one signerInfo shall be present\n");
	    break;
	}
	size = asn1.size;
	if(asn1_expect_obj(map, asn1.content, &size, &asn1, 0x02, 1, "\x01")) /* Version = 1 */
	    break;
	if(asn1_expect_objtype(map, asn1.next, &size, &asn1, 0x30)) /* issuerAndSerialNumber */
	    break;
	dsize = asn1.size;
	if(asn1_expect_objtype(map, asn1.content, &dsize, &deep, 0x30)) /* issuer */
	    break;
	if(asn1_expect_objtype(map, deep.next, &dsize, &deep, 0x02)) /* serial */
	    break;
	if(dsize) {
	    cli_dbgmsg("asn1_parse_mscat: extra data inside issuerAndSerialNumber\n");
	    break;
	}
	if(asn1_expect_algo(map, &asn1.next, &size, 5, "\x2b\x0e\x03\x02\x1a")) /* digestAlgorithm == sha1 */
	    break;

	if(asn1_expect_objtype(map, asn1.next, &size, &asn1, 0xa0)) /* authenticatedAttributes */
	    break;

	if(asn1_expect_algo(map, &asn1.next, &size, 9, "\x2a\x86\x48\x86\xf7\x0d\x01\x01\x01")) /* digestEncryptionAlgorithm == sha1 */
	    break;

	if(asn1_expect_objtype(map, asn1.next, &size, &asn1, 0x04)) /* encryptedDigest */
	    break;

	if(size && asn1_expect_objtype(map, asn1.next, &size, &asn1, 0xa1)) /* unauthenticatedAttributes */
	    break;

	if(size) {
	    cli_dbgmsg("asn1_parse_mscat: extra data inside signerInfo\n");
	    break;
	}

	cli_errmsg("asn1: parsing ok\n");
	return 0;
    } while(0);

    cli_errmsg("asn1: epic parsing fail\n");
    return 1;
}