/* GIO - GLib Input, Output and Certificateing Library

 *

 * Copyright (C) 2010 Red Hat, Inc.

 *

 * This library is free software; you can redistribute it and/or

 * modify it under the terms of the GNU Lesser General Public

 * License as published by the Free Software Foundation; either

 * version 2.1 of the License, or (at your option) any later version.

 *

 * This library is distributed in the hope that it will be useful,

 * but WITHOUT ANY WARRANTY; without even the implied warranty of

 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU

 * Lesser General Public License for more details.

 *

 * You should have received a copy of the GNU Lesser General

 * Public License along with this library; if not, see <http://www.gnu.org/licenses/>.

 */

#include "config.h"

#include "gtlscertificate.h"

#include <string.h>

#include "ginitable.h"

#include "gtlsbackend.h"

#include "gtlsconnection.h"

#include "glibintl.h"

/**

 * SECTION:gtlscertificate

 * @title: GTlsCertificate

 * @short_description: TLS certificate

 * @include: gio/gio.h

 * @see_also: #GTlsConnection

 *

 * A certificate used for TLS authentication and encryption.

 * This can represent either a certificate only (eg, the certificate

 * received by a client from a server), or the combination of

 * a certificate and a private key (which is needed when acting as a

 * #GTlsServerConnection).

 *

 * Since: 2.28

 */

/**

 * GTlsCertificate:

 *

 * Abstract base class for TLS certificate types.

 *

 * Since: 2.28

 */

G_DEFINE_ABSTRACT_TYPE (GTlsCertificate, g_tls_certificate, G_TYPE_OBJECT)

enum

{

  PROP_0,

  PROP_CERTIFICATE,

  PROP_CERTIFICATE_PEM,

  PROP_PRIVATE_KEY,

  PROP_PRIVATE_KEY_PEM,

  PROP_ISSUER

};

static void

g_tls_certificate_init (GTlsCertificate *cert)

{

}

static void

g_tls_certificate_get_property (GObject    *object,

				guint       prop_id,

				GValue     *value,

				GParamSpec *pspec)

{

  G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);

}

static void

g_tls_certificate_set_property (GObject      *object,

				guint         prop_id,

				const GValue *value,

				GParamSpec   *pspec)

{

  G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);

}

static void

g_tls_certificate_class_init (GTlsCertificateClass *class)

{

  GObjectClass *gobject_class = G_OBJECT_CLASS (class);

  gobject_class->set_property = g_tls_certificate_set_property;

  gobject_class->get_property = g_tls_certificate_get_property;

  /**

   * GTlsCertificate:certificate:

   *

   * The DER (binary) encoded representation of the certificate.

   * This property and the #GTlsCertificate:certificate-pem property

   * represent the same data, just in different forms.

   *

   * Since: 2.28

   */

  g_object_class_install_property (gobject_class, PROP_CERTIFICATE,

				   g_param_spec_boxed ("certificate",

						       P_("Certificate"),

						       P_("The DER representation of the certificate"),

						       G_TYPE_BYTE_ARRAY,

						       G_PARAM_READWRITE |

						       G_PARAM_CONSTRUCT_ONLY |

						       G_PARAM_STATIC_STRINGS));

  /**

   * GTlsCertificate:certificate-pem:

   *

   * The PEM (ASCII) encoded representation of the certificate.

   * This property and the #GTlsCertificate:certificate

   * property represent the same data, just in different forms.

   *

   * Since: 2.28

   */

  g_object_class_install_property (gobject_class, PROP_CERTIFICATE_PEM,

				   g_param_spec_string ("certificate-pem",

							P_("Certificate (PEM)"),

							P_("The PEM representation of the certificate"),

							NULL,

							G_PARAM_READWRITE |

							G_PARAM_CONSTRUCT_ONLY |

							G_PARAM_STATIC_STRINGS));

  /**

   * GTlsCertificate:private-key:

   *

   * The DER (binary) encoded representation of the certificate's

   * private key, in either PKCS#1 format or unencrypted PKCS#8

   * format. This property (or the #GTlsCertificate:private-key-pem

   * property) can be set when constructing a key (eg, from a file),

   * but cannot be read.

   *

   * PKCS#8 format is supported since 2.32; earlier releases only

   * support PKCS#1. You can use the `openssl rsa`

   * tool to convert PKCS#8 keys to PKCS#1.

   *

   * Since: 2.28

   */

  g_object_class_install_property (gobject_class, PROP_PRIVATE_KEY,

				   g_param_spec_boxed ("private-key",

						       P_("Private key"),

						       P_("The DER representation of the certificate’s private key"),

						       G_TYPE_BYTE_ARRAY,

						       G_PARAM_WRITABLE |

						       G_PARAM_CONSTRUCT_ONLY |

						       G_PARAM_STATIC_STRINGS));

  /**

   * GTlsCertificate:private-key-pem:

   *

   * The PEM (ASCII) encoded representation of the certificate's

   * private key in either PKCS#1 format ("`BEGIN RSA PRIVATE

   * KEY`") or unencrypted PKCS#8 format ("`BEGIN

   * PRIVATE KEY`"). This property (or the

   * #GTlsCertificate:private-key property) can be set when

   * constructing a key (eg, from a file), but cannot be read.

   *

   * PKCS#8 format is supported since 2.32; earlier releases only

   * support PKCS#1. You can use the `openssl rsa`

   * tool to convert PKCS#8 keys to PKCS#1.

   *

   * Since: 2.28

   */

  g_object_class_install_property (gobject_class, PROP_PRIVATE_KEY_PEM,

				   g_param_spec_string ("private-key-pem",

							P_("Private key (PEM)"),

							P_("The PEM representation of the certificate’s private key"),

							NULL,

							G_PARAM_WRITABLE |

							G_PARAM_CONSTRUCT_ONLY |

							G_PARAM_STATIC_STRINGS));

  /**

   * GTlsCertificate:issuer:

   *

   * A #GTlsCertificate representing the entity that issued this

   * certificate. If %NULL, this means that the certificate is either

   * self-signed, or else the certificate of the issuer is not

   * available.

   *

   * Since: 2.28

   */

  g_object_class_install_property (gobject_class, PROP_ISSUER,

				   g_param_spec_object ("issuer",

							P_("Issuer"),

							P_("The certificate for the issuing entity"),

							G_TYPE_TLS_CERTIFICATE,

							G_PARAM_READWRITE |

							G_PARAM_CONSTRUCT_ONLY |

							G_PARAM_STATIC_STRINGS));

}

static GTlsCertificate *

g_tls_certificate_new_internal (const gchar      *certificate_pem,

				const gchar      *private_key_pem,

				GTlsCertificate  *issuer,

				GError          **error)

{

  GObject *cert;

  GTlsBackend *backend;

  backend = g_tls_backend_get_default ();

  cert = g_initable_new (g_tls_backend_get_certificate_type (backend),

			 NULL, error,

			 "certificate-pem", certificate_pem,

			 "private-key-pem", private_key_pem,

			 "issuer", issuer,

			 NULL);

  return G_TLS_CERTIFICATE (cert);

}

#define PEM_CERTIFICATE_HEADER     "-----BEGIN CERTIFICATE-----"

#define PEM_CERTIFICATE_FOOTER     "-----END CERTIFICATE-----"

#define PEM_PKCS1_PRIVKEY_HEADER   "-----BEGIN RSA PRIVATE KEY-----"

#define PEM_PKCS1_PRIVKEY_FOOTER   "-----END RSA PRIVATE KEY-----"

#define PEM_PKCS8_PRIVKEY_HEADER   "-----BEGIN PRIVATE KEY-----"

#define PEM_PKCS8_PRIVKEY_FOOTER   "-----END PRIVATE KEY-----"

#define PEM_PKCS8_ENCRYPTED_HEADER "-----BEGIN ENCRYPTED PRIVATE KEY-----"

#define PEM_PKCS8_ENCRYPTED_FOOTER "-----END ENCRYPTED PRIVATE KEY-----"

static gchar *

parse_private_key (const gchar *data,

		   gsize data_len,

		   gboolean required,

		   GError **error)

{

  const gchar *start, *end, *footer;

  start = g_strstr_len (data, data_len, PEM_PKCS1_PRIVKEY_HEADER);

  if (start)

    footer = PEM_PKCS1_PRIVKEY_FOOTER;

  else

    {

      start = g_strstr_len (data, data_len, PEM_PKCS8_PRIVKEY_HEADER);

      if (start)

	footer = PEM_PKCS8_PRIVKEY_FOOTER;

      else

	{

	  start = g_strstr_len (data, data_len, PEM_PKCS8_ENCRYPTED_HEADER);

	  if (start)

	    {

	      g_set_error_literal (error, G_TLS_ERROR, G_TLS_ERROR_BAD_CERTIFICATE,

				   _("Cannot decrypt PEM-encoded private key"));

	    }

	  else if (required)

	    {

	      g_set_error_literal (error, G_TLS_ERROR, G_TLS_ERROR_BAD_CERTIFICATE,

				   _("No PEM-encoded private key found"));

	    }

	  return NULL;

	}

    }

  end = g_strstr_len (start, data_len - (data - start), footer);

  if (!end)

    {

      g_set_error_literal (error, G_TLS_ERROR, G_TLS_ERROR_BAD_CERTIFICATE,

			   _("Could not parse PEM-encoded private key"));

      return NULL;

    }

  end += strlen (footer);

  while (*end == '\r' || *end == '\n')

    end++;

  return g_strndup (start, end - start);

}

static gchar *

parse_next_pem_certificate (const gchar **data,

			    const gchar  *data_end,

			    gboolean      required,

			    GError      **error)

{

  const gchar *start, *end;

  start = g_strstr_len (*data, data_end - *data, PEM_CERTIFICATE_HEADER);

  if (!start)

    {

      if (required)

	{

	  g_set_error_literal (error, G_TLS_ERROR, G_TLS_ERROR_BAD_CERTIFICATE,

			       _("No PEM-encoded certificate found"));

	}

      return NULL;

    }

  end = g_strstr_len (start, data_end - start, PEM_CERTIFICATE_FOOTER);

  if (!end)

    {

      g_set_error_literal (error, G_TLS_ERROR, G_TLS_ERROR_BAD_CERTIFICATE,

			   _("Could not parse PEM-encoded certificate"));

      return NULL;

    }

  end += strlen (PEM_CERTIFICATE_FOOTER);

  while (*end == '\r' || *end == '\n')

    end++;

  *data = end;

  return g_strndup (start, end - start);

}

static GSList *

parse_and_create_certificate_list (const gchar  *data,

                                   gsize         data_len,

                                   GError      **error)

{

  GSList *first_pem_list = NULL, *pem_list = NULL;

  gchar *first_pem;

  const gchar *p, *end;

  p = data;

  end = p + data_len;

  /* Make sure we can load, at least, one certificate. */

  first_pem = parse_next_pem_certificate (&p, end, TRUE, error);

  if (!first_pem)

    return NULL;

  /* Create a list with a single element. If we load more certificates

   * below, we will concatenate the two lists at the end. */

  first_pem_list = g_slist_prepend (first_pem_list, first_pem);

  /* If we read one certificate successfully, let's see if we can read

   * some more. If not, we will simply return a list with the first one.

   */

  while (p && *p)

    {

      gchar *cert_pem;

      GError *error = NULL;

      cert_pem = parse_next_pem_certificate (&p, end, FALSE, &error);

      if (error)

        {

          g_slist_free_full (pem_list, g_free);

          g_error_free (error);

          return first_pem_list;

        }

      else if (!cert_pem)

        {

          break;

        }

      pem_list = g_slist_prepend (pem_list, cert_pem);

    }

  pem_list = g_slist_concat (pem_list, first_pem_list);

  return pem_list;

}

static GTlsCertificate *

create_certificate_chain_from_list (GSList       *pem_list,

                                    const gchar  *key_pem)

{

  GTlsCertificate *cert = NULL, *issuer = NULL, *root = NULL;

  GTlsCertificateFlags flags;

  GSList *pem;

  pem = pem_list;

  while (pem)

    {

      const gchar *key = NULL;

      /* Private key belongs only to the first certificate. */

      if (!pem->next)

        key = key_pem;

      /* We assume that the whole file is a certificate chain, so we use

       * each certificate as the issuer of the next one (list is in

       * reverse order).

       */

      issuer = cert;

      cert = g_tls_certificate_new_internal (pem->data, key, issuer, NULL);

      if (issuer)

        g_object_unref (issuer);

      if (!cert)

        return NULL;

      /* root will point to the last certificate in the file. */

      if (!root)

        root = cert;

      pem = g_slist_next (pem);

    }

  /* Verify that the certificates form a chain. (We don't care at this

   * point if there are other problems with it.)

   */

  flags = g_tls_certificate_verify (cert, NULL, root);

  if (flags & G_TLS_CERTIFICATE_UNKNOWN_CA)

    {

      /* It wasn't a chain, it's just a bunch of unrelated certs. */

      g_clear_object (&cert);

    }

  return cert;

}

static GTlsCertificate *

parse_and_create_certificate (const gchar  *data,

                              gsize         data_len,

                              const gchar  *key_pem,

                              GError      **error)

{

  GSList *pem_list;

  GTlsCertificate *cert;

  pem_list = parse_and_create_certificate_list (data, data_len, error);

  if (!pem_list)

    return NULL;

  /* We don't pass the error here because, if it fails, we still want to

   * load and return the first certificate.

   */

  cert = create_certificate_chain_from_list (pem_list, key_pem);

  if (!cert)

    {

      GSList *last = NULL;

      /* Get the first certificate (which is the last one as the list is

       * in reverse order).

       */

      last = g_slist_last (pem_list);

      cert = g_tls_certificate_new_internal (last->data, key_pem, NULL, error);

    }

  g_slist_free_full (pem_list, g_free);

  return cert;

}

/**

 * g_tls_certificate_new_from_pem:

 * @data: PEM-encoded certificate data

 * @length: the length of @data, or -1 if it's 0-terminated.

 * @error: #GError for error reporting, or %NULL to ignore.

 *

 * Creates a #GTlsCertificate from the PEM-encoded data in @data. If

 * @data includes both a certificate and a private key, then the

 * returned certificate will include the private key data as well. (See

 * the #GTlsCertificate:private-key-pem property for information about

 * supported formats.)

 *

 * The returned certificate will be the first certificate found in

 * @data. As of GLib 2.44, if @data contains more certificates it will

 * try to load a certificate chain. All certificates will be verified in

 * the order found (top-level certificate should be the last one in the

 * file) and the #GTlsCertificate:issuer property of each certificate

 * will be set accordingly if the verification succeeds. If any

 * certificate in the chain cannot be verified, the first certificate in

 * the file will still be returned.

 *

 * Returns: the new certificate, or %NULL if @data is invalid

 *

 * Since: 2.28

 */

GTlsCertificate *

g_tls_certificate_new_from_pem  (const gchar  *data,

				 gssize        length,

				 GError      **error)

{

  GError *child_error = NULL;

  gchar *key_pem;

  GTlsCertificate *cert;

  g_return_val_if_fail (data != NULL, NULL);

  g_return_val_if_fail (error == NULL || *error == NULL, NULL);

  if (length == -1)

    length = strlen (data);

  key_pem = parse_private_key (data, length, FALSE, &child_error);

  if (child_error != NULL)

    {

      g_propagate_error (error, child_error);

      return NULL;

    }

  cert = parse_and_create_certificate (data, length, key_pem, error);

  g_free (key_pem);

  return cert;

}

/**

 * g_tls_certificate_new_from_file:

 * @file: (type filename): file containing a PEM-encoded certificate to import

 * @error: #GError for error reporting, or %NULL to ignore.

 *

 * Creates a #GTlsCertificate from the PEM-encoded data in @file. The

 * returned certificate will be the first certificate found in @file. As

 * of GLib 2.44, if @file contains more certificates it will try to load

 * a certificate chain. All certificates will be verified in the order

 * found (top-level certificate should be the last one in the file) and

 * the #GTlsCertificate:issuer property of each certificate will be set

 * accordingly if the verification succeeds. If any certificate in the

 * chain cannot be verified, the first certificate in the file will

 * still be returned.

 *

 * If @file cannot be read or parsed, the function will return %NULL and

 * set @error. Otherwise, this behaves like

 * g_tls_certificate_new_from_pem().

 *

 * Returns: the new certificate, or %NULL on error

 *

 * Since: 2.28

 */

GTlsCertificate *

g_tls_certificate_new_from_file (const gchar  *file,

				 GError      **error)

{

  GTlsCertificate *cert;

  gchar *contents;

  gsize length;

  if (!g_file_get_contents (file, &contents, &length, error))

    return NULL;

  cert = g_tls_certificate_new_from_pem (contents, length, error);

  g_free (contents);

  return cert;

}

/**

 * g_tls_certificate_new_from_files:

 * @cert_file: (type filename): file containing one or more PEM-encoded

 *     certificates to import

 * @key_file: (type filename): file containing a PEM-encoded private key

 *     to import

 * @error: #GError for error reporting, or %NULL to ignore.

 *

 * Creates a #GTlsCertificate from the PEM-encoded data in @cert_file

 * and @key_file. The returned certificate will be the first certificate

 * found in @cert_file. As of GLib 2.44, if @cert_file contains more

 * certificates it will try to load a certificate chain. All

 * certificates will be verified in the order found (top-level

 * certificate should be the last one in the file) and the

 * #GTlsCertificate:issuer property of each certificate will be set

 * accordingly if the verification succeeds. If any certificate in the

 * chain cannot be verified, the first certificate in the file will

 * still be returned.

 *

 * If either file cannot be read or parsed, the function will return

 * %NULL and set @error. Otherwise, this behaves like

 * g_tls_certificate_new_from_pem().

 *

 * Returns: the new certificate, or %NULL on error

 *

 * Since: 2.28

 */

GTlsCertificate *

g_tls_certificate_new_from_files (const gchar  *cert_file,

                                  const gchar  *key_file,

                                  GError      **error)

{

  GTlsCertificate *cert;

  gchar *cert_data, *key_data;

  gsize cert_len, key_len;

  gchar *key_pem;

  if (!g_file_get_contents (key_file, &key_data, &key_len, error))

    return NULL;

  key_pem = parse_private_key (key_data, key_len, TRUE, error);

  g_free (key_data);

  if (!key_pem)

    return NULL;

  if (!g_file_get_contents (cert_file, &cert_data, &cert_len, error))

    {

      g_free (key_pem);

      return NULL;

    }

  cert = parse_and_create_certificate (cert_data, cert_len, key_pem, error);

  g_free (cert_data);

  g_free (key_pem);

  return cert;

}

/**

 * g_tls_certificate_list_new_from_file:

 * @file: (type filename): file containing PEM-encoded certificates to import

 * @error: #GError for error reporting, or %NULL to ignore.

 *

 * Creates one or more #GTlsCertificates from the PEM-encoded

 * data in @file. If @file cannot be read or parsed, the function will

 * return %NULL and set @error. If @file does not contain any

 * PEM-encoded certificates, this will return an empty list and not

 * set @error.

 *

 * Returns: (element-type Gio.TlsCertificate) (transfer full): a

 * #GList containing #GTlsCertificate objects. You must free the list

 * and its contents when you are done with it.

 *

 * Since: 2.28

 */

GList *

g_tls_certificate_list_new_from_file (const gchar  *file,

				      GError      **error)

{

  GQueue queue = G_QUEUE_INIT;

  gchar *contents, *end;

  const gchar *p;

  gsize length;

  if (!g_file_get_contents (file, &contents, &length, error))

    return NULL;

  end = contents + length;

  p = contents;

  while (p && *p)

    {

      gchar *cert_pem;

      GTlsCertificate *cert = NULL;

      GError *parse_error = NULL;

      cert_pem = parse_next_pem_certificate (&p, end, FALSE, &parse_error);

      if (cert_pem)

        {

          cert = g_tls_certificate_new_internal (cert_pem, NULL, NULL, &parse_error);

          g_free (cert_pem);

        }

      if (!cert)

        {

          if (parse_error)

            {

              g_propagate_error (error, parse_error);

              g_list_free_full (queue.head, g_object_unref);

              queue.head = NULL;

            }

          break;

        }

      g_queue_push_tail (&queue, cert);

    }

  g_free (contents);

  return queue.head;

}

/**

 * g_tls_certificate_get_issuer:

 * @cert: a #GTlsCertificate

 *

 * Gets the #GTlsCertificate representing @cert's issuer, if known

 *

 * Returns: (transfer none): The certificate of @cert's issuer,

 * or %NULL if @cert is self-signed or signed with an unknown

 * certificate.

 *

 * Since: 2.28

 */

GTlsCertificate *

g_tls_certificate_get_issuer (GTlsCertificate  *cert)

{

  GTlsCertificate *issuer;

  g_object_get (G_OBJECT (cert), "issuer", &issuer, NULL);

  if (issuer)

    g_object_unref (issuer);

  return issuer;

}

/**

 * g_tls_certificate_verify:

 * @cert: a #GTlsCertificate

 * @identity: (nullable): the expected peer identity

 * @trusted_ca: (nullable): the certificate of a trusted authority

 *

 * This verifies @cert and returns a set of #GTlsCertificateFlags

 * indicating any problems found with it. This can be used to verify a

 * certificate outside the context of making a connection, or to

 * check a certificate against a CA that is not part of the system

 * CA database.

 *

 * If @identity is not %NULL, @cert's name(s) will be compared against

 * it, and %G_TLS_CERTIFICATE_BAD_IDENTITY will be set in the return

 * value if it does not match. If @identity is %NULL, that bit will

 * never be set in the return value.

 *

 * If @trusted_ca is not %NULL, then @cert (or one of the certificates

 * in its chain) must be signed by it, or else

 * %G_TLS_CERTIFICATE_UNKNOWN_CA will be set in the return value. If

 * @trusted_ca is %NULL, that bit will never be set in the return

 * value.

 *

 * (All other #GTlsCertificateFlags values will always be set or unset

 * as appropriate.)

 *

 * Returns: the appropriate #GTlsCertificateFlags

 *

 * Since: 2.28

 */

GTlsCertificateFlags

g_tls_certificate_verify (GTlsCertificate     *cert,

			  GSocketConnectable  *identity,

			  GTlsCertificate     *trusted_ca)

{

  return G_TLS_CERTIFICATE_GET_CLASS (cert)->verify (cert, identity, trusted_ca);

}

/**

 * g_tls_certificate_is_same:

 * @cert_one: first certificate to compare

 * @cert_two: second certificate to compare

 *

 * Check if two #GTlsCertificate objects represent the same certificate.

 * The raw DER byte data of the two certificates are checked for equality.

 * This has the effect that two certificates may compare equal even if

 * their #GTlsCertificate:issuer, #GTlsCertificate:private-key, or

 * #GTlsCertificate:private-key-pem properties differ.

 *

 * Returns: whether the same or not

 *

 * Since: 2.34

 */

gboolean

g_tls_certificate_is_same (GTlsCertificate     *cert_one,

                           GTlsCertificate     *cert_two)

{

  GByteArray *b1, *b2;

  gboolean equal;

  g_return_val_if_fail (G_IS_TLS_CERTIFICATE (cert_one), FALSE);

  g_return_val_if_fail (G_IS_TLS_CERTIFICATE (cert_two), FALSE);

  g_object_get (cert_one, "certificate", &b1, NULL);

  g_object_get (cert_two, "certificate", &b2, NULL);

  equal = (b1->len == b2->len &&

           memcmp (b1->data, b2->data, b1->len) == 0);

  g_byte_array_unref (b1);

  g_byte_array_unref (b2);

  return equal;

}