/* 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 <ctype.h>
#include <string.h>

#include <openssl_grpc/asn1.h>
#include <openssl_grpc/asn1t.h>
#include <openssl_grpc/buf.h>
#include <openssl_grpc/err.h>
#include <openssl_grpc/mem.h>
#include <openssl_grpc/obj.h>
#include <openssl_grpc/stack.h>
#include <openssl_grpc/x509.h>

#include "../asn1/asn1_locl.h"
#include "../internal.h"


typedef STACK_OF(X509_NAME_ENTRY) STACK_OF_X509_NAME_ENTRY;
DEFINE_STACK_OF(STACK_OF_X509_NAME_ENTRY)

/*
 * Maximum length of X509_NAME: much larger than anything we should
 * ever see in practice.
 */

#define X509_NAME_MAX (1024 * 1024)

static int x509_name_ex_d2i(ASN1_VALUE **val,
                            const unsigned char **in, long len,
                            const ASN1_ITEM *it,
                            int tag, int aclass, char opt, ASN1_TLC *ctx);

static int x509_name_ex_i2d(ASN1_VALUE **val, unsigned char **out,
                            const ASN1_ITEM *it, int tag, int aclass);
static int x509_name_ex_new(ASN1_VALUE **val, const ASN1_ITEM *it);
static void x509_name_ex_free(ASN1_VALUE **val, const ASN1_ITEM *it);

static int x509_name_encode(X509_NAME *a);
static int x509_name_canon(X509_NAME *a);
static int asn1_string_canon(ASN1_STRING *out, ASN1_STRING *in);
static int i2d_name_canon(STACK_OF(STACK_OF_X509_NAME_ENTRY) * intname,
                          unsigned char **in);

ASN1_SEQUENCE(X509_NAME_ENTRY) = {
        ASN1_SIMPLE(X509_NAME_ENTRY, object, ASN1_OBJECT),
        ASN1_SIMPLE(X509_NAME_ENTRY, value, ASN1_PRINTABLE)
} ASN1_SEQUENCE_END(X509_NAME_ENTRY)

IMPLEMENT_ASN1_FUNCTIONS(X509_NAME_ENTRY)
IMPLEMENT_ASN1_DUP_FUNCTION(X509_NAME_ENTRY)

/*
 * For the "Name" type we need a SEQUENCE OF { SET OF X509_NAME_ENTRY } so
 * declare two template wrappers for this
 */

ASN1_ITEM_TEMPLATE(X509_NAME_ENTRIES) =
        ASN1_EX_TEMPLATE_TYPE(ASN1_TFLG_SET_OF, 0, RDNS, X509_NAME_ENTRY)
ASN1_ITEM_TEMPLATE_END(X509_NAME_ENTRIES)

ASN1_ITEM_TEMPLATE(X509_NAME_INTERNAL) =
        ASN1_EX_TEMPLATE_TYPE(ASN1_TFLG_SEQUENCE_OF, 0, Name, X509_NAME_ENTRIES)
ASN1_ITEM_TEMPLATE_END(X509_NAME_INTERNAL)

/*
 * Normally that's where it would end: we'd have two nested STACK structures
 * representing the ASN1. Unfortunately X509_NAME uses a completely different
 * form and caches encodings so we have to process the internal form and
 * convert to the external form.
 */

static const ASN1_EXTERN_FUNCS x509_name_ff = {
    NULL,
    x509_name_ex_new,
    x509_name_ex_free,
    0,                          /* Default clear behaviour is OK */
    x509_name_ex_d2i,
    x509_name_ex_i2d,
    NULL,
};

IMPLEMENT_EXTERN_ASN1(X509_NAME, V_ASN1_SEQUENCE, x509_name_ff)

IMPLEMENT_ASN1_FUNCTIONS(X509_NAME)

IMPLEMENT_ASN1_DUP_FUNCTION(X509_NAME)

static int x509_name_ex_new(ASN1_VALUE **val, const ASN1_ITEM *it)
{
    X509_NAME *ret = NULL;
    ret = OPENSSL_malloc(sizeof(X509_NAME));
    if (!ret)
        goto memerr;
    if ((ret->entries = sk_X509_NAME_ENTRY_new_null()) == NULL)
        goto memerr;
    if ((ret->bytes = BUF_MEM_new()) == NULL)
        goto memerr;
    ret->canon_enc = NULL;
    ret->canon_enclen = 0;
    ret->modified = 1;
    *val = (ASN1_VALUE *)ret;
    return 1;

 memerr:
    OPENSSL_PUT_ERROR(X509, ERR_R_MALLOC_FAILURE);
    if (ret) {
        if (ret->entries)
            sk_X509_NAME_ENTRY_free(ret->entries);
        OPENSSL_free(ret);
    }
    return 0;
}

static void x509_name_ex_free(ASN1_VALUE **pval, const ASN1_ITEM *it)
{
    X509_NAME *a;
    if (!pval || !*pval)
        return;
    a = (X509_NAME *)*pval;

    BUF_MEM_free(a->bytes);
    sk_X509_NAME_ENTRY_pop_free(a->entries, X509_NAME_ENTRY_free);
    if (a->canon_enc)
        OPENSSL_free(a->canon_enc);
    OPENSSL_free(a);
    *pval = NULL;
}

static void local_sk_X509_NAME_ENTRY_free(STACK_OF(X509_NAME_ENTRY) *ne)
{
    sk_X509_NAME_ENTRY_free(ne);
}

static void local_sk_X509_NAME_ENTRY_pop_free(STACK_OF(X509_NAME_ENTRY) *ne)
{
    sk_X509_NAME_ENTRY_pop_free(ne, X509_NAME_ENTRY_free);
}

static int x509_name_ex_d2i(ASN1_VALUE **val,
                            const unsigned char **in, long len,
                            const ASN1_ITEM *it, int tag, int aclass,
                            char opt, ASN1_TLC *ctx)
{
    const unsigned char *p = *in, *q;
    union {
        STACK_OF(STACK_OF_X509_NAME_ENTRY) *s;
        ASN1_VALUE *a;
    } intname = {
        NULL
    };
    union {
        X509_NAME *x;
        ASN1_VALUE *a;
    } nm = {
        NULL
    };
    size_t i, j;
    int ret;
    STACK_OF(X509_NAME_ENTRY) *entries;
    X509_NAME_ENTRY *entry;
    /* Bound the size of an X509_NAME we are willing to parse. */
    if (len > X509_NAME_MAX) {
        len = X509_NAME_MAX;
    }
    q = p;

    /* Get internal representation of Name */
    ret = ASN1_item_ex_d2i(&intname.a,
                           &p, len, ASN1_ITEM_rptr(X509_NAME_INTERNAL),
                           tag, aclass, opt, ctx);

    if (ret <= 0)
        return ret;

    if (*val)
        x509_name_ex_free(val, NULL);
    if (!x509_name_ex_new(&nm.a, NULL))
        goto err;
    /* We've decoded it: now cache encoding */
    if (!BUF_MEM_grow(nm.x->bytes, p - q))
        goto err;
    OPENSSL_memcpy(nm.x->bytes->data, q, p - q);

    /* Convert internal representation to X509_NAME structure */
    for (i = 0; i < sk_STACK_OF_X509_NAME_ENTRY_num(intname.s); i++) {
        entries = sk_STACK_OF_X509_NAME_ENTRY_value(intname.s, i);
        for (j = 0; j < sk_X509_NAME_ENTRY_num(entries); j++) {
            entry = sk_X509_NAME_ENTRY_value(entries, j);
            entry->set = i;
            if (!sk_X509_NAME_ENTRY_push(nm.x->entries, entry))
                goto err;
            (void)sk_X509_NAME_ENTRY_set(entries, j, NULL);
        }
    }
    ret = x509_name_canon(nm.x);
    if (!ret)
        goto err;
    sk_STACK_OF_X509_NAME_ENTRY_pop_free(intname.s,
                                         local_sk_X509_NAME_ENTRY_free);
    nm.x->modified = 0;
    *val = nm.a;
    *in = p;
    return ret;
 err:
    if (nm.x != NULL)
        X509_NAME_free(nm.x);
    sk_STACK_OF_X509_NAME_ENTRY_pop_free(intname.s,
                                         local_sk_X509_NAME_ENTRY_pop_free);
    OPENSSL_PUT_ERROR(X509, ERR_R_ASN1_LIB);
    return 0;
}

static int x509_name_ex_i2d(ASN1_VALUE **val, unsigned char **out,
                            const ASN1_ITEM *it, int tag, int aclass)
{
    int ret;
    X509_NAME *a = (X509_NAME *)*val;
    if (a->modified) {
        ret = x509_name_encode(a);
        if (ret < 0)
            return ret;
        ret = x509_name_canon(a);
        if (ret < 0)
            return ret;
    }
    ret = a->bytes->length;
    if (out != NULL) {
        OPENSSL_memcpy(*out, a->bytes->data, ret);
        *out += ret;
    }
    return ret;
}

static int x509_name_encode(X509_NAME *a)
{
    union {
        STACK_OF(STACK_OF_X509_NAME_ENTRY) *s;
        ASN1_VALUE *a;
    } intname = {
        NULL
    };
    int len;
    unsigned char *p;
    STACK_OF(X509_NAME_ENTRY) *entries = NULL;
    X509_NAME_ENTRY *entry;
    int set = -1;
    size_t i;
    intname.s = sk_STACK_OF_X509_NAME_ENTRY_new_null();
    if (!intname.s)
        goto memerr;
    for (i = 0; i < sk_X509_NAME_ENTRY_num(a->entries); i++) {
        entry = sk_X509_NAME_ENTRY_value(a->entries, i);
        if (entry->set != set) {
            entries = sk_X509_NAME_ENTRY_new_null();
            if (!entries)
                goto memerr;
            if (!sk_STACK_OF_X509_NAME_ENTRY_push(intname.s, entries)) {
                sk_X509_NAME_ENTRY_free(entries);
                goto memerr;
            }
            set = entry->set;
        }
        if (!sk_X509_NAME_ENTRY_push(entries, entry))
            goto memerr;
    }
    len = ASN1_item_ex_i2d(&intname.a, NULL,
                           ASN1_ITEM_rptr(X509_NAME_INTERNAL), -1, -1);
    if (!BUF_MEM_grow(a->bytes, len))
        goto memerr;
    p = (unsigned char *)a->bytes->data;
    ASN1_item_ex_i2d(&intname.a,
                     &p, ASN1_ITEM_rptr(X509_NAME_INTERNAL), -1, -1);
    sk_STACK_OF_X509_NAME_ENTRY_pop_free(intname.s,
                                         local_sk_X509_NAME_ENTRY_free);
    a->modified = 0;
    return len;
 memerr:
    sk_STACK_OF_X509_NAME_ENTRY_pop_free(intname.s,
                                         local_sk_X509_NAME_ENTRY_free);
    OPENSSL_PUT_ERROR(X509, ERR_R_MALLOC_FAILURE);
    return -1;
}

/*
 * This function generates the canonical encoding of the Name structure. In
 * it all strings are converted to UTF8, leading, trailing and multiple
 * spaces collapsed, converted to lower case and the leading SEQUENCE header
 * removed. In future we could also normalize the UTF8 too. By doing this
 * comparison of Name structures can be rapidly perfomed by just using
 * OPENSSL_memcmp() of the canonical encoding. By omitting the leading SEQUENCE name
 * constraints of type dirName can also be checked with a simple OPENSSL_memcmp().
 */

static int x509_name_canon(X509_NAME *a)
{
    unsigned char *p;
    STACK_OF(STACK_OF_X509_NAME_ENTRY) *intname = NULL;
    STACK_OF(X509_NAME_ENTRY) *entries = NULL;
    X509_NAME_ENTRY *entry, *tmpentry = NULL;
    int set = -1, ret = 0, len;
    size_t i;

    if (a->canon_enc) {
        OPENSSL_free(a->canon_enc);
        a->canon_enc = NULL;
    }
    /* Special case: empty X509_NAME => null encoding */
    if (sk_X509_NAME_ENTRY_num(a->entries) == 0) {
        a->canon_enclen = 0;
        return 1;
    }
    intname = sk_STACK_OF_X509_NAME_ENTRY_new_null();
    if (!intname)
        goto err;
    for (i = 0; i < sk_X509_NAME_ENTRY_num(a->entries); i++) {
        entry = sk_X509_NAME_ENTRY_value(a->entries, i);
        if (entry->set != set) {
            entries = sk_X509_NAME_ENTRY_new_null();
            if (!entries)
                goto err;
            if (!sk_STACK_OF_X509_NAME_ENTRY_push(intname, entries)) {
                sk_X509_NAME_ENTRY_free(entries);
                goto err;
            }
            set = entry->set;
        }
        tmpentry = X509_NAME_ENTRY_new();
        if (tmpentry == NULL)
            goto err;
        tmpentry->object = OBJ_dup(entry->object);
        if (!asn1_string_canon(tmpentry->value, entry->value))
            goto err;
        if (!sk_X509_NAME_ENTRY_push(entries, tmpentry))
            goto err;
        tmpentry = NULL;
    }

    /* Finally generate encoding */

    len = i2d_name_canon(intname, NULL);
    if (len < 0) {
        goto err;
    }
    a->canon_enclen = len;

    p = OPENSSL_malloc(a->canon_enclen);

    if (!p)
        goto err;

    a->canon_enc = p;

    i2d_name_canon(intname, &p);

    ret = 1;

 err:

    if (tmpentry)
        X509_NAME_ENTRY_free(tmpentry);
    if (intname)
        sk_STACK_OF_X509_NAME_ENTRY_pop_free(intname,
                                             local_sk_X509_NAME_ENTRY_pop_free);
    return ret;
}

/* Bitmap of all the types of string that will be canonicalized. */

#define ASN1_MASK_CANON \
        (B_ASN1_UTF8STRING | B_ASN1_BMPSTRING | B_ASN1_UNIVERSALSTRING \
        | B_ASN1_PRINTABLESTRING | B_ASN1_T61STRING | B_ASN1_IA5STRING \
        | B_ASN1_VISIBLESTRING)

static int asn1_string_canon(ASN1_STRING *out, ASN1_STRING *in)
{
    unsigned char *to, *from;
    int len, i;

    /* If type not in bitmask just copy string across */
    if (!(ASN1_tag2bit(in->type) & ASN1_MASK_CANON)) {
        if (!ASN1_STRING_copy(out, in))
            return 0;
        return 1;
    }

    out->type = V_ASN1_UTF8STRING;
    out->length = ASN1_STRING_to_UTF8(&out->data, in);
    if (out->length == -1)
        return 0;

    to = out->data;
    from = to;

    len = out->length;

    /*
     * Convert string in place to canonical form. Ultimately we may need to
     * handle a wider range of characters but for now ignore anything with
     * MSB set and rely on the isspace() and tolower() functions.
     */

    /* Ignore leading spaces */
    while ((len > 0) && !(*from & 0x80) && isspace(*from)) {
        from++;
        len--;
    }

    to = from + len;

    /* Ignore trailing spaces */
    while ((len > 0) && !(to[-1] & 0x80) && isspace(to[-1])) {
        to--;
        len--;
    }

    to = out->data;

    i = 0;
    while (i < len) {
        /* If MSB set just copy across */
        if (*from & 0x80) {
            *to++ = *from++;
            i++;
        }
        /* Collapse multiple spaces */
        else if (isspace(*from)) {
            /* Copy one space across */
            *to++ = ' ';
            /*
             * Ignore subsequent spaces. Note: don't need to check len here
             * because we know the last character is a non-space so we can't
             * overflow.
             */
            do {
                from++;
                i++;
            }
            while (!(*from & 0x80) && isspace(*from));
        } else {
            *to++ = OPENSSL_tolower(*from);
            from++;
            i++;
        }
    }

    out->length = to - out->data;

    return 1;

}

static int i2d_name_canon(STACK_OF(STACK_OF_X509_NAME_ENTRY) * _intname,
                          unsigned char **in)
{
    int len, ltmp;
    size_t i;
    ASN1_VALUE *v;
    STACK_OF(ASN1_VALUE) *intname = (STACK_OF(ASN1_VALUE) *)_intname;

    len = 0;
    for (i = 0; i < sk_ASN1_VALUE_num(intname); i++) {
        v = sk_ASN1_VALUE_value(intname, i);
        ltmp = ASN1_item_ex_i2d(&v, in,
                                ASN1_ITEM_rptr(X509_NAME_ENTRIES), -1, -1);
        if (ltmp < 0)
            return ltmp;
        len += ltmp;
    }
    return len;
}

int X509_NAME_set(X509_NAME **xn, X509_NAME *name)
{
    if ((name = X509_NAME_dup(name)) == NULL)
        return 0;
    X509_NAME_free(*xn);
    *xn = name;
    return 1;
}

IMPLEMENT_ASN1_SET_OF(X509_NAME_ENTRY)

int X509_NAME_ENTRY_set(const X509_NAME_ENTRY *ne)
{
    return ne->set;
}

int X509_NAME_get0_der(X509_NAME *nm, const unsigned char **pder,
                       size_t *pderlen)
{
    /* Make sure encoding is valid */
    if (i2d_X509_NAME(nm, NULL) <= 0)
        return 0;
    if (pder != NULL)
        *pder = (unsigned char *)nm->bytes->data;
    if (pderlen != NULL)
        *pderlen = nm->bytes->length;
    return 1;
}
