/**
 * \file x509.h
 *
 * \brief X.509 generic defines and structures
 *
 *  Copyright (C) 2006-2013, Brainspark B.V.
 *
 *  This file is part of PolarSSL (http://www.polarssl.org)
 *  Lead Maintainer: Paul Bakker <polarssl_maintainer at polarssl.org>
 *
 *  All rights reserved.
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation; either version 2 of the License, or
 *  (at your option) any later version.
 *
 *  This program 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 General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License along
 *  with this program; if not, write to the Free Software Foundation, Inc.,
 *  51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 */
#ifndef POLARSSL_X509_H
#define POLARSSL_X509_H

#include "config.h"

#include "asn1.h"
#include "pk.h"

#if defined(POLARSSL_RSA_C)
#include "rsa.h"
#endif

/**
 * \addtogroup x509_module
 * \{
 */

/**
 * \name X509 Error codes
 * \{
 */
#define POLARSSL_ERR_X509_FEATURE_UNAVAILABLE              -0x2080  /**< Unavailable feature, e.g. RSA hashing/encryption combination. */
#define POLARSSL_ERR_X509_CERT_INVALID_PEM                 -0x2100  /**< The PEM-encoded certificate contains invalid elements, e.g. invalid character. */ 
#define POLARSSL_ERR_X509_CERT_INVALID_FORMAT              -0x2180  /**< The certificate format is invalid, e.g. different type expected. */
#define POLARSSL_ERR_X509_CERT_INVALID_VERSION             -0x2200  /**< The certificate version element is invalid. */
#define POLARSSL_ERR_X509_CERT_INVALID_SERIAL              -0x2280  /**< The serial tag or value is invalid. */
#define POLARSSL_ERR_X509_CERT_INVALID_ALG                 -0x2300  /**< The algorithm tag or value is invalid. */
#define POLARSSL_ERR_X509_CERT_INVALID_NAME                -0x2380  /**< The name tag or value is invalid. */
#define POLARSSL_ERR_X509_CERT_INVALID_DATE                -0x2400  /**< The date tag or value is invalid. */
#define POLARSSL_ERR_X509_CERT_INVALID_SIGNATURE           -0x2480  /**< The signature tag or value invalid. */
#define POLARSSL_ERR_X509_CERT_INVALID_EXTENSIONS          -0x2500  /**< The extension tag or value is invalid. */
#define POLARSSL_ERR_X509_CERT_UNKNOWN_VERSION             -0x2580  /**< Certificate or CRL has an unsupported version number. */
#define POLARSSL_ERR_X509_CERT_UNKNOWN_SIG_ALG             -0x2600  /**< Signature algorithm (oid) is unsupported. */
#define POLARSSL_ERR_X509_CERT_SIG_MISMATCH                -0x2680  /**< Certificate signature algorithms do not match. (see \c ::x509_cert sig_oid) */
#define POLARSSL_ERR_X509_CERT_VERIFY_FAILED               -0x2700  /**< Certificate verification failed, e.g. CRL, CA or signature check failed. */
#define POLARSSL_ERR_X509_CERT_UNKNOWN_FORMAT              -0x2780  /**< Format not recognized as DER or PEM. */
#define POLARSSL_ERR_X509_INVALID_INPUT                    -0x2800  /**< Input invalid. */
#define POLARSSL_ERR_X509_MALLOC_FAILED                    -0x2880  /**< Allocation of memory failed. */
#define POLARSSL_ERR_X509_FILE_IO_ERROR                    -0x2900  /**< Read/write of file failed. */
#define POLARSSL_ERR_X509WRITE_UNKNOWN_OID                -0x5F80  /**< Requested OID is unknown. */
#define POLARSSL_ERR_X509WRITE_BAD_INPUT_DATA             -0x5F00  /**< Failed to allocate memory. */
#define POLARSSL_ERR_X509WRITE_MALLOC_FAILED              -0x5E80  /**< Failed to allocate memory. */
/* \} name */

/**
 * \name X509 Verify codes
 * \{
 */
#define BADCERT_EXPIRED             0x01  /**< The certificate validity has expired. */
#define BADCERT_REVOKED             0x02  /**< The certificate has been revoked (is on a CRL). */
#define BADCERT_CN_MISMATCH         0x04  /**< The certificate Common Name (CN) does not match with the expected CN. */
#define BADCERT_NOT_TRUSTED         0x08  /**< The certificate is not correctly signed by the trusted CA. */
#define BADCRL_NOT_TRUSTED          0x10  /**< CRL is not correctly signed by the trusted CA. */
#define BADCRL_EXPIRED              0x20  /**< CRL is expired. */
#define BADCERT_MISSING             0x40  /**< Certificate was missing. */
#define BADCERT_SKIP_VERIFY         0x80  /**< Certificate verification was skipped. */
#define BADCERT_OTHER             0x0100  /**< Other reason (can be used by verify callback) */
/* \} name */
/* \} addtogroup x509_module */

/*
 * X.509 v3 Key Usage Extension flags
 */
#define KU_DIGITAL_SIGNATURE            (0x80)  /* bit 0 */
#define KU_NON_REPUDIATION              (0x40)  /* bit 1 */
#define KU_KEY_ENCIPHERMENT             (0x20)  /* bit 2 */
#define KU_DATA_ENCIPHERMENT            (0x10)  /* bit 3 */
#define KU_KEY_AGREEMENT                (0x08)  /* bit 4 */
#define KU_KEY_CERT_SIGN                (0x04)  /* bit 5 */
#define KU_CRL_SIGN                     (0x02)  /* bit 6 */

/*
 * Netscape certificate types
 * (http://www.mozilla.org/projects/security/pki/nss/tech-notes/tn3.html)
 */

#define NS_CERT_TYPE_SSL_CLIENT         (0x80)  /* bit 0 */
#define NS_CERT_TYPE_SSL_SERVER         (0x40)  /* bit 1 */
#define NS_CERT_TYPE_EMAIL              (0x20)  /* bit 2 */
#define NS_CERT_TYPE_OBJECT_SIGNING     (0x10)  /* bit 3 */
#define NS_CERT_TYPE_RESERVED           (0x08)  /* bit 4 */
#define NS_CERT_TYPE_SSL_CA             (0x04)  /* bit 5 */
#define NS_CERT_TYPE_EMAIL_CA           (0x02)  /* bit 6 */
#define NS_CERT_TYPE_OBJECT_SIGNING_CA  (0x01)  /* bit 7 */

/*
 * X.509 extension types
 */
#define EXT_AUTHORITY_KEY_IDENTIFIER    (1 << 0)
#define EXT_SUBJECT_KEY_IDENTIFIER      (1 << 1)
#define EXT_KEY_USAGE                   (1 << 2)
#define EXT_CERTIFICATE_POLICIES        (1 << 3)
#define EXT_POLICY_MAPPINGS             (1 << 4)
#define EXT_SUBJECT_ALT_NAME            (1 << 5)
#define EXT_ISSUER_ALT_NAME             (1 << 6)
#define EXT_SUBJECT_DIRECTORY_ATTRS     (1 << 7)
#define EXT_BASIC_CONSTRAINTS           (1 << 8)
#define EXT_NAME_CONSTRAINTS            (1 << 9)
#define EXT_POLICY_CONSTRAINTS          (1 << 10)
#define EXT_EXTENDED_KEY_USAGE          (1 << 11)
#define EXT_CRL_DISTRIBUTION_POINTS     (1 << 12)
#define EXT_INIHIBIT_ANYPOLICY          (1 << 13)
#define EXT_FRESHEST_CRL                (1 << 14)

#define EXT_NS_CERT_TYPE                (1 << 16)

/*
 * Storage format identifiers
 * Recognized formats: PEM and DER
 */
#define X509_FORMAT_DER                 1
#define X509_FORMAT_PEM                 2

#ifdef __cplusplus
extern "C" {
#endif

/**
 * \addtogroup x509_module
 * \{ */

/**
 * \name Structures for parsing X.509 certificates, CRLs and CSRs
 * \{
 */

/**
 * Type-length-value structure that allows for ASN1 using DER.
 */
typedef asn1_buf x509_buf;

/**
 * Container for ASN1 bit strings.
 */
typedef asn1_bitstring x509_bitstring;

/**
 * Container for ASN1 named information objects.
 * It allows for Relative Distinguished Names (e.g. cn=polarssl,ou=code,etc.).
 */
typedef asn1_named_data x509_name;

/**
 * Container for a sequence of ASN.1 items
 */
typedef asn1_sequence x509_sequence;

/** Container for date and time (precision in seconds). */
typedef struct _x509_time
{
    int year, mon, day;         /**< Date. */
    int hour, min, sec;         /**< Time. */
}
x509_time;

/** \} name Structures for parsing X.509 certificates, CRLs and CSRs */
/** \} addtogroup x509_module */

/**
 * \name Functions to read in DHM parameters, a certificate, CRL or private RSA key
 * \{
 */

#if defined(POLARSSL_RSA_C)
/** \ingroup x509_module */
/**
 * \brief          Parse a private RSA key
 *
 * \param rsa      RSA context to be initialized
 * \param key      input buffer
 * \param keylen   size of the buffer
 * \param pwd      password for decryption (optional)
 * \param pwdlen   size of the password
 *
 * \return         0 if successful, or a specific X509 or PEM error code
 */
int x509parse_key_rsa( rsa_context *rsa,
                       const unsigned char *key, size_t keylen,
                       const unsigned char *pwd, size_t pwdlen );

#if defined(POLARSSL_FS_IO)
/** \ingroup x509_module */
/**
 * \brief          Load and parse a private RSA key
 *
 * \param rsa      RSA context to be initialized
 * \param path     filename to read the private key from
 * \param password password to decrypt the file (can be NULL)
 *
 * \return         0 if successful, or a specific X509 or PEM error code
 */
int x509parse_keyfile_rsa( rsa_context *rsa, const char *path,
                           const char *password );
#endif /* POLARSSL_FS_IO */

/** \ingroup x509_module */
/**
 * \brief          Parse a public RSA key
 *
 * \param rsa      RSA context to be initialized
 * \param key      input buffer
 * \param keylen   size of the buffer
 *
 * \return         0 if successful, or a specific X509 or PEM error code
 */
int x509parse_public_key_rsa( rsa_context *rsa,
                       const unsigned char *key, size_t keylen );

#if defined(POLARSSL_FS_IO)
/** \ingroup x509_module */
/**
 * \brief          Load and parse a public RSA key
 *
 * \param rsa      RSA context to be initialized
 * \param path     filename to read the private key from
 *
 * \return         0 if successful, or a specific X509 or PEM error code
 */
int x509parse_public_keyfile_rsa( rsa_context *rsa, const char *path );
#endif /* POLARSSL_FS_IO */
#endif /* POLARSSL_RSA_C */

/** \} name Functions to read in DHM parameters, a certificate, CRL or private RSA key */

/**
 * \brief          Store the certificate DN in printable form into buf;
 *                 no more than size characters will be written.
 *
 * \param buf      Buffer to write to
 * \param size     Maximum size of buffer
 * \param dn       The X509 name to represent
 *
 * \return         The amount of data written to the buffer, or -1 in
 *                 case of an error.
 */
int x509parse_dn_gets( char *buf, size_t size, const x509_name *dn );

/**
 * \brief          Store the certificate serial in printable form into buf;
 *                 no more than size characters will be written.
 *
 * \param buf      Buffer to write to
 * \param size     Maximum size of buffer
 * \param serial   The X509 serial to represent
 *
 * \return         The amount of data written to the buffer, or -1 in
 *                 case of an error.
 */
int x509parse_serial_gets( char *buf, size_t size, const x509_buf *serial );

/**
 * \brief          Give an known OID, return its descriptive string.
 *
 * \param oid      buffer containing the oid
 *
 * \return         Return a string if the OID is known,
 *                 or NULL otherwise.
 */
const char *x509_oid_get_description( x509_buf *oid );

/**
 * \brief          Give an OID, return a string version of its OID number.
 *                 (Deprecated. Use oid_get_numeric_string() instead)
 *
 * \param buf      Buffer to write to
 * \param size     Maximum size of buffer
 * \param oid      Buffer containing the OID
 *
 * \return         The amount of data written to the buffer, or -1 in
 *                 case of an error.
 */
int x509_oid_get_numeric_string( char *buf, size_t size, x509_buf *oid );

/**
 * \brief          Check a given x509_time against the system time and check
 *                 if it is valid.
 *
 * \param time     x509_time to check
 *
 * \return         Return 0 if the x509_time is still valid,
 *                 or 1 otherwise.
 */
int x509parse_time_expired( const x509_time *time );

/**
 * \brief          Checkup routine
 *
 * \return         0 if successful, or 1 if the test failed
 */
int x509_self_test( int verbose );

/*
 * Internal module functions
 */
int x509_get_name( unsigned char **p, const unsigned char *end,
                   x509_name *cur );
int x509_get_alg_null( unsigned char **p, const unsigned char *end,
                       x509_buf *alg );
int x509_get_sig( unsigned char **p, const unsigned char *end, x509_buf *sig );
int x509_get_sig_alg( const x509_buf *sig_oid, md_type_t *md_alg,
                      pk_type_t *pk_alg );
int x509_load_file( const char *path, unsigned char **buf, size_t *n );
int x509_key_size_helper( char *buf, size_t size, const char *name );
int x509_get_time( unsigned char **p, const unsigned char *end,
                   x509_time *time );
int x509_get_serial( unsigned char **p, const unsigned char *end,
                     x509_buf *serial );
int x509_get_ext( unsigned char **p, const unsigned char *end,
                  x509_buf *ext, int tag );

int x509write_string_to_names( asn1_named_data **head, char *name );
int x509_set_extension( asn1_named_data **head, const char *oid, size_t oid_len,                       int critical, const unsigned char *val, size_t val_len );
int x509_write_extensions( unsigned char **p, unsigned char *start,
                           asn1_named_data *first );
int x509_write_names( unsigned char **p, unsigned char *start,
                      asn1_named_data *first );
int x509_write_sig( unsigned char **p, unsigned char *start,
                    const char *oid, size_t oid_len,
                    unsigned char *sig, size_t size );
#endif /* x509.h */