// Copyright 1999-2016 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.

// X509 v3 extension utilities

#include <stdio.h>

#include <openssl/bio.h>

#include <openssl/conf.h>

#include <openssl/mem.h>

#include <openssl/x509.h>

// Extension printing routines

static int unknown_ext_print(BIO *out, const X509_EXTENSION *ext,

                             unsigned long flag, int indent, int supported);

// Print out a name+value stack

static void X509V3_EXT_val_prn(BIO *out, const STACK_OF(CONF_VALUE) *val,

                               int indent, int ml) {

  if (!val) {

    return;

  }

  if (!ml || !sk_CONF_VALUE_num(val)) {

    BIO_printf(out, "%*s", indent, "");

    if (!sk_CONF_VALUE_num(val)) {

      BIO_puts(out, "<EMPTY>\n");

    }

  }

  for (size_t i = 0; i < sk_CONF_VALUE_num(val); i++) {

    if (ml) {

      BIO_printf(out, "%*s", indent, "");

    } else if (i > 0) {

      BIO_printf(out, ", ");

    }

    const CONF_VALUE *nval = sk_CONF_VALUE_value(val, i);

    if (!nval->name) {

      BIO_puts(out, nval->value);

    } else if (!nval->value) {

      BIO_puts(out, nval->name);

    } else {

      BIO_printf(out, "%s:%s", nval->name, nval->value);

    }

    if (ml) {

      BIO_puts(out, "\n");

    }

  }

}

// Main routine: print out a general extension

int X509V3_EXT_print(BIO *out, const X509_EXTENSION *ext, unsigned long flag,

                     int indent) {

  const X509V3_EXT_METHOD *method = X509V3_EXT_get(ext);

  if (method == NULL) {

    return unknown_ext_print(out, ext, flag, indent, 0);

  }

  const ASN1_STRING *ext_data = X509_EXTENSION_get_data(ext);

  const unsigned char *p = ASN1_STRING_get0_data(ext_data);

  void *ext_str = ASN1_item_d2i(NULL, &p, ASN1_STRING_length(ext_data),

                                ASN1_ITEM_ptr(method->it));

  if (!ext_str) {

    return unknown_ext_print(out, ext, flag, indent, 1);

  }

  char *value = NULL;

  STACK_OF(CONF_VALUE) *nval = NULL;

  int ok = 0;

  if (method->i2s) {

    if (!(value = method->i2s(method, ext_str))) {

      goto err;

    }

    BIO_printf(out, "%*s%s", indent, "", value);

  } else if (method->i2v) {

    if (!(nval = method->i2v(method, ext_str, NULL))) {

      goto err;

    }

    X509V3_EXT_val_prn(out, nval, indent,

                       method->ext_flags & X509V3_EXT_MULTILINE);

  } else if (method->i2r) {

    if (!method->i2r(method, ext_str, out, indent)) {

      goto err;

    }

  } else {

    OPENSSL_PUT_ERROR(X509V3, X509V3_R_OPERATION_NOT_DEFINED);

    goto err;

  }

  ok = 1;

err:

  sk_CONF_VALUE_pop_free(nval, X509V3_conf_free);

  OPENSSL_free(value);

  ASN1_item_free(reinterpret_cast<ASN1_VALUE *>(ext_str),

                 ASN1_ITEM_ptr(method->it));

  return ok;

}

int X509V3_extensions_print(BIO *bp, const char *title,

                            const STACK_OF(X509_EXTENSION) *exts,

                            unsigned long flag, int indent) {

  size_t i;

  int j;

  if (sk_X509_EXTENSION_num(exts) <= 0) {

    return 1;

  }

  if (title) {

    BIO_printf(bp, "%*s%s:\n", indent, "", title);

    indent += 4;

  }

  for (i = 0; i < sk_X509_EXTENSION_num(exts); i++) {

    const X509_EXTENSION *ex = sk_X509_EXTENSION_value(exts, i);

    if (indent && BIO_printf(bp, "%*s", indent, "") <= 0) {

      return 0;

    }

    const ASN1_OBJECT *obj = X509_EXTENSION_get_object(ex);

    i2a_ASN1_OBJECT(bp, obj);

    j = X509_EXTENSION_get_critical(ex);

    if (BIO_printf(bp, ": %s\n", j ? "critical" : "") <= 0) {

      return 0;

    }

    if (!X509V3_EXT_print(bp, ex, flag, indent + 4)) {

      BIO_printf(bp, "%*s", indent + 4, "");

      ASN1_STRING_print(bp, X509_EXTENSION_get_data(ex));

    }

    if (BIO_write(bp, "\n", 1) <= 0) {

      return 0;

    }

  }

  return 1;

}

static int unknown_ext_print(BIO *out, const X509_EXTENSION *ext,

                             unsigned long flag, int indent, int supported) {

  switch (flag & X509V3_EXT_UNKNOWN_MASK) {

    case X509V3_EXT_DEFAULT:

      return 0;

    case X509V3_EXT_ERROR_UNKNOWN:

      if (supported) {

        BIO_printf(out, "%*s<Parse Error>", indent, "");

      } else {

        BIO_printf(out, "%*s<Not Supported>", indent, "");

      }

      return 1;

    case X509V3_EXT_PARSE_UNKNOWN:

    case X509V3_EXT_DUMP_UNKNOWN: {

      const ASN1_STRING *data = X509_EXTENSION_get_data(ext);

      return BIO_hexdump(out, ASN1_STRING_get0_data(data),

                         ASN1_STRING_length(data), indent);

    }

    default:

      return 1;

  }

}

int X509V3_EXT_print_fp(FILE *fp, const X509_EXTENSION *ext, int flag,

                        int indent) {

  BIO *bio_tmp;

  int ret;

  if (!(bio_tmp = BIO_new_fp(fp, BIO_NOCLOSE))) {

    return 0;

  }

  ret = X509V3_EXT_print(bio_tmp, ext, flag, indent);

  BIO_free(bio_tmp);

  return ret;

}