// Copyright 2000-2016 The OpenSSL Project Authors. All Rights Reserved.

//

// Licensed under the Apache License, Version 2.0 (the "License");

// you may not use this file except in compliance with the License.

// You may obtain a copy of the License at

//

//     https://www.apache.org/licenses/LICENSE-2.0

//

// Unless required by applicable law or agreed to in writing, software

// distributed under the License is distributed on an "AS IS" BASIS,

// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.

// See the License for the specific language governing permissions and

// limitations under the License.

#include <openssl/x509.h>

#include <assert.h>

#include <inttypes.h>

#include <string.h>

#include <openssl/asn1.h>

#include <openssl/bio.h>

#include <openssl/obj.h>

static int maybe_write(BIO *out, const void *buf, int len) {

  // If `out` is NULL, ignore the output but report the length.

  return out == nullptr || BIO_write(out, buf, len) == len;

}

// do_indent prints `indent` spaces to `out`.

static int do_indent(BIO *out, int indent) {

  for (int i = 0; i < indent; i++) {

    if (!maybe_write(out, " ", 1)) {

      return 0;

    }

  }

  return 1;

}

#define FN_WIDTH_LN 25

#define FN_WIDTH_SN 10

static int do_name_ex(BIO *out, const X509_NAME *n, int indent,

                      unsigned long flags) {

  int prev = -1, orflags;

  int outlen, len;

  const 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(out, 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;

  }

  int cnt = X509_NAME_entry_count(n);

  for (int i = 0; i < cnt; i++) {

    const X509_NAME_ENTRY *ent;

    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 == X509_NAME_ENTRY_set(ent)) {

        if (!maybe_write(out, sep_mv, sep_mv_len)) {

          return -1;

        }

        outlen += sep_mv_len;

      } else {

        if (!maybe_write(out, sep_dn, sep_dn_len)) {

          return -1;

        }

        outlen += sep_dn_len;

        if (!do_indent(out, indent)) {

          return -1;

        }

        outlen += indent;

      }

    }

    prev = X509_NAME_ENTRY_set(ent);

    const ASN1_OBJECT *fn = X509_NAME_ENTRY_get_object(ent);

    const ASN1_STRING *val = X509_NAME_ENTRY_get_data(ent);

    assert((flags & XN_FLAG_FN_MASK) == XN_FLAG_FN_SN);

    // Print the short name if available, otherwise serialize the OID.

    char objtmp[80];

    const char *objbuf = nullptr;

    int fn_nid = OBJ_obj2nid(fn);

    if (fn_nid != NID_undef) {

      objbuf = OBJ_nid2sn(fn_nid);

    }

    if (objbuf == nullptr) {

      OBJ_obj2txt(objtmp, sizeof(objtmp), fn, /*always_return_oid=*/1);

      objbuf = objtmp;

    }

    int objlen = strlen(objbuf);

    if (!maybe_write(out, objbuf, objlen) ||

        !maybe_write(out, 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 = ASN1_STRING_print_ex(out, val, flags | orflags);

    if (len < 0) {

      return -1;

    }

    outlen += len;

  }

  return outlen;

}

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(out, nm, indent, flags);

}

int X509_NAME_print_ex_fp(FILE *fp, const X509_NAME *nm, int indent,

                          unsigned long flags) {

  BIO *bio = nullptr;

  if (fp != nullptr) {

    // If `fp` is NULL, this function returns the number of bytes without

    // writing.

    bio = BIO_new_fp(fp, BIO_NOCLOSE);

    if (bio == nullptr) {

      return -1;

    }

  }

  int ret = X509_NAME_print_ex(bio, nm, indent, flags);

  BIO_free(bio);

  return ret;

}