x509_crt.h

00001 /**
00002  * \file x509_crt.h
00003  *
00004  * \brief X.509 certificate parsing and writing
00005  */
00006 /*
00007  *  Copyright (C) 2006-2015, ARM Limited, All Rights Reserved
00008  *  SPDX-License-Identifier: Apache-2.0
00009  *
00010  *  Licensed under the Apache License, Version 2.0 (the "License"); you may
00011  *  not use this file except in compliance with the License.
00012  *  You may obtain a copy of the License at
00013  *
00014  *  http://www.apache.org/licenses/LICENSE-2.0
00015  *
00016  *  Unless required by applicable law or agreed to in writing, software
00017  *  distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
00018  *  WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
00019  *  See the License for the specific language governing permissions and
00020  *  limitations under the License.
00021  *
00022  *  This file is part of mbed TLS (https://tls.mbed.org)
00023  */
00024 #ifndef MBEDTLS_X509_CRT_H
00025 #define MBEDTLS_X509_CRT_H
00026 
00027 #if !defined(MBEDTLS_CONFIG_FILE)
00028 #include "config.h"
00029 #else
00030 #include MBEDTLS_CONFIG_FILE
00031 #endif
00032 
00033 #include "x509.h"
00034 #include "x509_crl.h"
00035 
00036 /**
00037  * \addtogroup x509_module
00038  * \{
00039  */
00040 
00041 #ifdef __cplusplus
00042 extern "C" {
00043 #endif
00044 
00045 /**
00046  * \name Structures and functions for parsing and writing X.509 certificates
00047  * \{
00048  */
00049 
00050 /**
00051  * Container for an X.509 certificate. The certificate may be chained.
00052  */
00053 typedef struct mbedtls_x509_crt
00054 {
00055     mbedtls_x509_buf raw;               /**< The raw certificate data (DER). */
00056     mbedtls_x509_buf tbs;               /**< The raw certificate body (DER). The part that is To Be Signed. */
00057 
00058     int version;                /**< The X.509 version. (1=v1, 2=v2, 3=v3) */
00059     mbedtls_x509_buf serial;            /**< Unique id for certificate issued by a specific CA. */
00060     mbedtls_x509_buf sig_oid;           /**< Signature algorithm, e.g. sha1RSA */
00061 
00062     mbedtls_x509_buf issuer_raw;        /**< The raw issuer data (DER). Used for quick comparison. */
00063     mbedtls_x509_buf subject_raw;       /**< The raw subject data (DER). Used for quick comparison. */
00064 
00065     mbedtls_x509_name issuer;           /**< The parsed issuer data (named information object). */
00066     mbedtls_x509_name subject;          /**< The parsed subject data (named information object). */
00067 
00068     mbedtls_x509_time valid_from;       /**< Start time of certificate validity. */
00069     mbedtls_x509_time valid_to;         /**< End time of certificate validity. */
00070 
00071     mbedtls_pk_context pk;              /**< Container for the public key context. */
00072 
00073     mbedtls_x509_buf issuer_id;         /**< Optional X.509 v2/v3 issuer unique identifier. */
00074     mbedtls_x509_buf subject_id;        /**< Optional X.509 v2/v3 subject unique identifier. */
00075     mbedtls_x509_buf v3_ext;            /**< Optional X.509 v3 extensions.  */
00076     mbedtls_x509_sequence subject_alt_names;    /**< Optional list of Subject Alternative Names (Only dNSName supported). */
00077 
00078     int ext_types;              /**< Bit string containing detected and parsed extensions */
00079     int ca_istrue;              /**< Optional Basic Constraint extension value: 1 if this certificate belongs to a CA, 0 otherwise. */
00080     int max_pathlen;            /**< Optional Basic Constraint extension value: The maximum path length to the root certificate. Path length is 1 higher than RFC 5280 'meaning', so 1+ */
00081 
00082     unsigned int key_usage;     /**< Optional key usage extension value: See the values in x509.h */
00083 
00084     mbedtls_x509_sequence ext_key_usage; /**< Optional list of extended key usage OIDs. */
00085 
00086     unsigned char ns_cert_type; /**< Optional Netscape certificate type extension value: See the values in x509.h */
00087 
00088     mbedtls_x509_buf sig;               /**< Signature: hash of the tbs part signed with the private key. */
00089     mbedtls_md_type_t sig_md;           /**< Internal representation of the MD algorithm of the signature algorithm, e.g. MBEDTLS_MD_SHA256 */
00090     mbedtls_pk_type_t sig_pk;           /**< Internal representation of the Public Key algorithm of the signature algorithm, e.g. MBEDTLS_PK_RSA */
00091     void *sig_opts;             /**< Signature options to be passed to mbedtls_pk_verify_ext(), e.g. for RSASSA-PSS */
00092 
00093     struct mbedtls_x509_crt *next;     /**< Next certificate in the CA-chain. */
00094 }
00095 mbedtls_x509_crt;
00096 
00097 /**
00098  * Build flag from an algorithm/curve identifier (pk, md, ecp)
00099  * Since 0 is always XXX_NONE, ignore it.
00100  */
00101 #define MBEDTLS_X509_ID_FLAG( id )   ( 1 << ( id - 1 ) )
00102 
00103 /**
00104  * Security profile for certificate verification.
00105  *
00106  * All lists are bitfields, built by ORing flags from MBEDTLS_X509_ID_FLAG().
00107  */
00108 typedef struct
00109 {
00110     uint32_t allowed_mds;       /**< MDs for signatures         */
00111     uint32_t allowed_pks;       /**< PK algs for signatures     */
00112     uint32_t allowed_curves;    /**< Elliptic curves for ECDSA  */
00113     uint32_t rsa_min_bitlen;    /**< Minimum size for RSA keys  */
00114 }
00115 mbedtls_x509_crt_profile;
00116 
00117 #define MBEDTLS_X509_CRT_VERSION_1              0
00118 #define MBEDTLS_X509_CRT_VERSION_2              1
00119 #define MBEDTLS_X509_CRT_VERSION_3              2
00120 
00121 #define MBEDTLS_X509_RFC5280_MAX_SERIAL_LEN 32
00122 #define MBEDTLS_X509_RFC5280_UTC_TIME_LEN   15
00123 
00124 #if !defined( MBEDTLS_X509_MAX_FILE_PATH_LEN )
00125 #define MBEDTLS_X509_MAX_FILE_PATH_LEN 512
00126 #endif
00127 
00128 /**
00129  * Container for writing a certificate (CRT)
00130  */
00131 typedef struct mbedtls_x509write_cert
00132 {
00133     int version;
00134     mbedtls_mpi serial;
00135     mbedtls_pk_context *subject_key;
00136     mbedtls_pk_context *issuer_key;
00137     mbedtls_asn1_named_data *subject;
00138     mbedtls_asn1_named_data *issuer;
00139     mbedtls_md_type_t md_alg;
00140     char not_before[MBEDTLS_X509_RFC5280_UTC_TIME_LEN + 1];
00141     char not_after[MBEDTLS_X509_RFC5280_UTC_TIME_LEN + 1];
00142     mbedtls_asn1_named_data *extensions;
00143 }
00144 mbedtls_x509write_cert;
00145 
00146 #if defined(MBEDTLS_X509_CRT_PARSE_C)
00147 /**
00148  * Default security profile. Should provide a good balance between security
00149  * and compatibility with current deployments.
00150  */
00151 extern const mbedtls_x509_crt_profile mbedtls_x509_crt_profile_default;
00152 
00153 /**
00154  * Expected next default profile. Recommended for new deployments.
00155  * Currently targets a 128-bit security level, except for RSA-2048.
00156  */
00157 extern const mbedtls_x509_crt_profile mbedtls_x509_crt_profile_next;
00158 
00159 /**
00160  * NSA Suite B profile.
00161  */
00162 extern const mbedtls_x509_crt_profile mbedtls_x509_crt_profile_suiteb;
00163 
00164 /**
00165  * \brief          Parse a single DER formatted certificate and add it
00166  *                 to the chained list.
00167  *
00168  * \param chain    points to the start of the chain
00169  * \param buf      buffer holding the certificate DER data
00170  * \param buflen   size of the buffer
00171  *
00172  * \return         0 if successful, or a specific X509 or PEM error code
00173  */
00174 int mbedtls_x509_crt_parse_der( mbedtls_x509_crt *chain, const unsigned char *buf,
00175                         size_t buflen );
00176 
00177 /**
00178  * \brief          Parse one or more certificates and add them
00179  *                 to the chained list. Parses permissively. If some
00180  *                 certificates can be parsed, the result is the number
00181  *                 of failed certificates it encountered. If none complete
00182  *                 correctly, the first error is returned.
00183  *
00184  * \param chain    points to the start of the chain
00185  * \param buf      buffer holding the certificate data in PEM or DER format
00186  * \param buflen   size of the buffer
00187  *                 (including the terminating null byte for PEM data)
00188  *
00189  * \return         0 if all certificates parsed successfully, a positive number
00190  *                 if partly successful or a specific X509 or PEM error code
00191  */
00192 int mbedtls_x509_crt_parse( mbedtls_x509_crt *chain, const unsigned char *buf, size_t buflen );
00193 
00194 #if defined(MBEDTLS_FS_IO)
00195 /**
00196  * \brief          Load one or more certificates and add them
00197  *                 to the chained list. Parses permissively. If some
00198  *                 certificates can be parsed, the result is the number
00199  *                 of failed certificates it encountered. If none complete
00200  *                 correctly, the first error is returned.
00201  *
00202  * \param chain    points to the start of the chain
00203  * \param path     filename to read the certificates from
00204  *
00205  * \return         0 if all certificates parsed successfully, a positive number
00206  *                 if partly successful or a specific X509 or PEM error code
00207  */
00208 int mbedtls_x509_crt_parse_file( mbedtls_x509_crt *chain, const char *path );
00209 
00210 /**
00211  * \brief          Load one or more certificate files from a path and add them
00212  *                 to the chained list. Parses permissively. If some
00213  *                 certificates can be parsed, the result is the number
00214  *                 of failed certificates it encountered. If none complete
00215  *                 correctly, the first error is returned.
00216  *
00217  * \param chain    points to the start of the chain
00218  * \param path     directory / folder to read the certificate files from
00219  *
00220  * \return         0 if all certificates parsed successfully, a positive number
00221  *                 if partly successful or a specific X509 or PEM error code
00222  */
00223 int mbedtls_x509_crt_parse_path( mbedtls_x509_crt *chain, const char *path );
00224 #endif /* MBEDTLS_FS_IO */
00225 
00226 /**
00227  * \brief          Returns an informational string about the
00228  *                 certificate.
00229  *
00230  * \param buf      Buffer to write to
00231  * \param size     Maximum size of buffer
00232  * \param prefix   A line prefix
00233  * \param crt      The X509 certificate to represent
00234  *
00235  * \return         The length of the string written (not including the
00236  *                 terminated nul byte), or a negative error code.
00237  */
00238 int mbedtls_x509_crt_info( char *buf, size_t size, const char *prefix,
00239                    const mbedtls_x509_crt *crt );
00240 
00241 /**
00242  * \brief          Returns an informational string about the
00243  *                 verification status of a certificate.
00244  *
00245  * \param buf      Buffer to write to
00246  * \param size     Maximum size of buffer
00247  * \param prefix   A line prefix
00248  * \param flags    Verification flags created by mbedtls_x509_crt_verify()
00249  *
00250  * \return         The length of the string written (not including the
00251  *                 terminated nul byte), or a negative error code.
00252  */
00253 int mbedtls_x509_crt_verify_info( char *buf, size_t size, const char *prefix,
00254                           uint32_t flags );
00255 
00256 /**
00257  * \brief          Verify the certificate signature
00258  *
00259  *                 The verify callback is a user-supplied callback that
00260  *                 can clear / modify / add flags for a certificate. If set,
00261  *                 the verification callback is called for each
00262  *                 certificate in the chain (from the trust-ca down to the
00263  *                 presented crt). The parameters for the callback are:
00264  *                 (void *parameter, mbedtls_x509_crt *crt, int certificate_depth,
00265  *                 int *flags). With the flags representing current flags for
00266  *                 that specific certificate and the certificate depth from
00267  *                 the bottom (Peer cert depth = 0).
00268  *
00269  *                 All flags left after returning from the callback
00270  *                 are also returned to the application. The function should
00271  *                 return 0 for anything (including invalid certificates)
00272  *                 other than fatal error, as a non-zero return code
00273  *                 immediately aborts the verification process. For fatal
00274  *                 errors, a specific error code should be used (different
00275  *                 from MBEDTLS_ERR_X509_CERT_VERIFY_FAILED which should not
00276  *                 be returned at this point), or MBEDTLS_ERR_X509_FATAL_ERROR
00277  *                 can be used if no better code is available.
00278  *
00279  * \note           In case verification failed, the results can be displayed
00280  *                 using \c mbedtls_x509_crt_verify_info()
00281  *
00282  * \note           Same as \c mbedtls_x509_crt_verify_with_profile() with the
00283  *                 default security profile.
00284  *
00285  * \note           It is your responsibility to provide up-to-date CRLs for
00286  *                 all trusted CAs. If no CRL is provided for the CA that was
00287  *                 used to sign the certificate, CRL verification is skipped
00288  *                 silently, that is *without* setting any flag.
00289  *
00290  * \param crt      a certificate (chain) to be verified
00291  * \param trust_ca the list of trusted CAs
00292  * \param ca_crl   the list of CRLs for trusted CAs (see note above)
00293  * \param cn       expected Common Name (can be set to
00294  *                 NULL if the CN must not be verified)
00295  * \param flags    result of the verification
00296  * \param f_vrfy   verification function
00297  * \param p_vrfy   verification parameter
00298  *
00299  * \return         0 (and flags set to 0) if the chain was verified and valid,
00300  *                 MBEDTLS_ERR_X509_CERT_VERIFY_FAILED if the chain was verified
00301  *                 but found to be invalid, in which case *flags will have one
00302  *                 or more MBEDTLS_X509_BADCERT_XXX or MBEDTLS_X509_BADCRL_XXX
00303  *                 flags set, or another error (and flags set to 0xffffffff)
00304  *                 in case of a fatal error encountered during the
00305  *                 verification process.
00306  */
00307 int mbedtls_x509_crt_verify( mbedtls_x509_crt *crt,
00308                      mbedtls_x509_crt *trust_ca,
00309                      mbedtls_x509_crl *ca_crl,
00310                      const char *cn, uint32_t *flags,
00311                      int (*f_vrfy)(void *, mbedtls_x509_crt *, int, uint32_t *),
00312                      void *p_vrfy );
00313 
00314 /**
00315  * \brief          Verify the certificate signature according to profile
00316  *
00317  * \note           Same as \c mbedtls_x509_crt_verify(), but with explicit
00318  *                 security profile.
00319  *
00320  * \note           The restrictions on keys (RSA minimum size, allowed curves
00321  *                 for ECDSA) apply to all certificates: trusted root,
00322  *                 intermediate CAs if any, and end entity certificate.
00323  *
00324  * \param crt      a certificate (chain) to be verified
00325  * \param trust_ca the list of trusted CAs
00326  * \param ca_crl   the list of CRLs for trusted CAs
00327  * \param profile  security profile for verification
00328  * \param cn       expected Common Name (can be set to
00329  *                 NULL if the CN must not be verified)
00330  * \param flags    result of the verification
00331  * \param f_vrfy   verification function
00332  * \param p_vrfy   verification parameter
00333  *
00334  * \return         0 if successful or MBEDTLS_ERR_X509_CERT_VERIFY_FAILED
00335  *                 in which case *flags will have one or more
00336  *                 MBEDTLS_X509_BADCERT_XXX or MBEDTLS_X509_BADCRL_XXX flags
00337  *                 set,
00338  *                 or another error in case of a fatal error encountered
00339  *                 during the verification process.
00340  */
00341 int mbedtls_x509_crt_verify_with_profile( mbedtls_x509_crt *crt,
00342                      mbedtls_x509_crt *trust_ca,
00343                      mbedtls_x509_crl *ca_crl,
00344                      const mbedtls_x509_crt_profile *profile,
00345                      const char *cn, uint32_t *flags,
00346                      int (*f_vrfy)(void *, mbedtls_x509_crt *, int, uint32_t *),
00347                      void *p_vrfy );
00348 
00349 #if defined(MBEDTLS_X509_CHECK_KEY_USAGE)
00350 /**
00351  * \brief          Check usage of certificate against keyUsage extension.
00352  *
00353  * \param crt      Leaf certificate used.
00354  * \param usage    Intended usage(s) (eg MBEDTLS_X509_KU_KEY_ENCIPHERMENT
00355  *                 before using the certificate to perform an RSA key
00356  *                 exchange).
00357  *
00358  * \note           Except for decipherOnly and encipherOnly, a bit set in the
00359  *                 usage argument means this bit MUST be set in the
00360  *                 certificate. For decipherOnly and encipherOnly, it means
00361  *                 that bit MAY be set.
00362  *
00363  * \return         0 is these uses of the certificate are allowed,
00364  *                 MBEDTLS_ERR_X509_BAD_INPUT_DATA if the keyUsage extension
00365  *                 is present but does not match the usage argument.
00366  *
00367  * \note           You should only call this function on leaf certificates, on
00368  *                 (intermediate) CAs the keyUsage extension is automatically
00369  *                 checked by \c mbedtls_x509_crt_verify().
00370  */
00371 int mbedtls_x509_crt_check_key_usage( const mbedtls_x509_crt *crt,
00372                                       unsigned int usage );
00373 #endif /* MBEDTLS_X509_CHECK_KEY_USAGE) */
00374 
00375 #if defined(MBEDTLS_X509_CHECK_EXTENDED_KEY_USAGE)
00376 /**
00377  * \brief           Check usage of certificate against extendedKeyUsage.
00378  *
00379  * \param crt       Leaf certificate used.
00380  * \param usage_oid Intended usage (eg MBEDTLS_OID_SERVER_AUTH or
00381  *                  MBEDTLS_OID_CLIENT_AUTH).
00382  * \param usage_len Length of usage_oid (eg given by MBEDTLS_OID_SIZE()).
00383  *
00384  * \return          0 if this use of the certificate is allowed,
00385  *                  MBEDTLS_ERR_X509_BAD_INPUT_DATA if not.
00386  *
00387  * \note            Usually only makes sense on leaf certificates.
00388  */
00389 int mbedtls_x509_crt_check_extended_key_usage( const mbedtls_x509_crt *crt,
00390                                                const char *usage_oid,
00391                                                size_t usage_len );
00392 #endif /* MBEDTLS_X509_CHECK_EXTENDED_KEY_USAGE */
00393 
00394 #if defined(MBEDTLS_X509_CRL_PARSE_C)
00395 /**
00396  * \brief          Verify the certificate revocation status
00397  *
00398  * \param crt      a certificate to be verified
00399  * \param crl      the CRL to verify against
00400  *
00401  * \return         1 if the certificate is revoked, 0 otherwise
00402  *
00403  */
00404 int mbedtls_x509_crt_is_revoked( const mbedtls_x509_crt *crt, const mbedtls_x509_crl *crl );
00405 #endif /* MBEDTLS_X509_CRL_PARSE_C */
00406 
00407 /**
00408  * \brief          Initialize a certificate (chain)
00409  *
00410  * \param crt      Certificate chain to initialize
00411  */
00412 void mbedtls_x509_crt_init( mbedtls_x509_crt *crt );
00413 
00414 /**
00415  * \brief          Unallocate all certificate data
00416  *
00417  * \param crt      Certificate chain to free
00418  */
00419 void mbedtls_x509_crt_free( mbedtls_x509_crt *crt );
00420 #endif /* MBEDTLS_X509_CRT_PARSE_C */
00421 
00422 /* \} name */
00423 /* \} addtogroup x509_module */
00424 
00425 #if defined(MBEDTLS_X509_CRT_WRITE_C)
00426 /**
00427  * \brief           Initialize a CRT writing context
00428  *
00429  * \param ctx       CRT context to initialize
00430  */
00431 void mbedtls_x509write_crt_init( mbedtls_x509write_cert *ctx );
00432 
00433 /**
00434  * \brief           Set the verion for a Certificate
00435  *                  Default: MBEDTLS_X509_CRT_VERSION_3
00436  *
00437  * \param ctx       CRT context to use
00438  * \param version   version to set (MBEDTLS_X509_CRT_VERSION_1, MBEDTLS_X509_CRT_VERSION_2 or
00439  *                                  MBEDTLS_X509_CRT_VERSION_3)
00440  */
00441 void mbedtls_x509write_crt_set_version( mbedtls_x509write_cert *ctx, int version );
00442 
00443 /**
00444  * \brief           Set the serial number for a Certificate.
00445  *
00446  * \param ctx       CRT context to use
00447  * \param serial    serial number to set
00448  *
00449  * \return          0 if successful
00450  */
00451 int mbedtls_x509write_crt_set_serial( mbedtls_x509write_cert *ctx, const mbedtls_mpi *serial );
00452 
00453 /**
00454  * \brief           Set the validity period for a Certificate
00455  *                  Timestamps should be in string format for UTC timezone
00456  *                  i.e. "YYYYMMDDhhmmss"
00457  *                  e.g. "20131231235959" for December 31st 2013
00458  *                       at 23:59:59
00459  *
00460  * \param ctx       CRT context to use
00461  * \param not_before    not_before timestamp
00462  * \param not_after     not_after timestamp
00463  *
00464  * \return          0 if timestamp was parsed successfully, or
00465  *                  a specific error code
00466  */
00467 int mbedtls_x509write_crt_set_validity( mbedtls_x509write_cert *ctx, const char *not_before,
00468                                 const char *not_after );
00469 
00470 /**
00471  * \brief           Set the issuer name for a Certificate
00472  *                  Issuer names should contain a comma-separated list
00473  *                  of OID types and values:
00474  *                  e.g. "C=UK,O=ARM,CN=mbed TLS CA"
00475  *
00476  * \param ctx           CRT context to use
00477  * \param issuer_name   issuer name to set
00478  *
00479  * \return          0 if issuer name was parsed successfully, or
00480  *                  a specific error code
00481  */
00482 int mbedtls_x509write_crt_set_issuer_name( mbedtls_x509write_cert *ctx,
00483                                    const char *issuer_name );
00484 
00485 /**
00486  * \brief           Set the subject name for a Certificate
00487  *                  Subject names should contain a comma-separated list
00488  *                  of OID types and values:
00489  *                  e.g. "C=UK,O=ARM,CN=mbed TLS Server 1"
00490  *
00491  * \param ctx           CRT context to use
00492  * \param subject_name  subject name to set
00493  *
00494  * \return          0 if subject name was parsed successfully, or
00495  *                  a specific error code
00496  */
00497 int mbedtls_x509write_crt_set_subject_name( mbedtls_x509write_cert *ctx,
00498                                     const char *subject_name );
00499 
00500 /**
00501  * \brief           Set the subject public key for the certificate
00502  *
00503  * \param ctx       CRT context to use
00504  * \param key       public key to include
00505  */
00506 void mbedtls_x509write_crt_set_subject_key( mbedtls_x509write_cert *ctx, mbedtls_pk_context *key );
00507 
00508 /**
00509  * \brief           Set the issuer key used for signing the certificate
00510  *
00511  * \param ctx       CRT context to use
00512  * \param key       private key to sign with
00513  */
00514 void mbedtls_x509write_crt_set_issuer_key( mbedtls_x509write_cert *ctx, mbedtls_pk_context *key );
00515 
00516 /**
00517  * \brief           Set the MD algorithm to use for the signature
00518  *                  (e.g. MBEDTLS_MD_SHA1)
00519  *
00520  * \param ctx       CRT context to use
00521  * \param md_alg    MD algorithm to use
00522  */
00523 void mbedtls_x509write_crt_set_md_alg( mbedtls_x509write_cert *ctx, mbedtls_md_type_t md_alg );
00524 
00525 /**
00526  * \brief           Generic function to add to or replace an extension in the
00527  *                  CRT
00528  *
00529  * \param ctx       CRT context to use
00530  * \param oid       OID of the extension
00531  * \param oid_len   length of the OID
00532  * \param critical  if the extension is critical (per the RFC's definition)
00533  * \param val       value of the extension OCTET STRING
00534  * \param val_len   length of the value data
00535  *
00536  * \return          0 if successful, or a MBEDTLS_ERR_X509_ALLOC_FAILED
00537  */
00538 int mbedtls_x509write_crt_set_extension( mbedtls_x509write_cert *ctx,
00539                                  const char *oid, size_t oid_len,
00540                                  int critical,
00541                                  const unsigned char *val, size_t val_len );
00542 
00543 /**
00544  * \brief           Set the basicConstraints extension for a CRT
00545  *
00546  * \param ctx       CRT context to use
00547  * \param is_ca     is this a CA certificate
00548  * \param max_pathlen   maximum length of certificate chains below this
00549  *                      certificate (only for CA certificates, -1 is
00550  *                      inlimited)
00551  *
00552  * \return          0 if successful, or a MBEDTLS_ERR_X509_ALLOC_FAILED
00553  */
00554 int mbedtls_x509write_crt_set_basic_constraints( mbedtls_x509write_cert *ctx,
00555                                          int is_ca, int max_pathlen );
00556 
00557 #if defined(MBEDTLS_SHA1_C)
00558 /**
00559  * \brief           Set the subjectKeyIdentifier extension for a CRT
00560  *                  Requires that mbedtls_x509write_crt_set_subject_key() has been
00561  *                  called before
00562  *
00563  * \param ctx       CRT context to use
00564  *
00565  * \return          0 if successful, or a MBEDTLS_ERR_X509_ALLOC_FAILED
00566  */
00567 int mbedtls_x509write_crt_set_subject_key_identifier( mbedtls_x509write_cert *ctx );
00568 
00569 /**
00570  * \brief           Set the authorityKeyIdentifier extension for a CRT
00571  *                  Requires that mbedtls_x509write_crt_set_issuer_key() has been
00572  *                  called before
00573  *
00574  * \param ctx       CRT context to use
00575  *
00576  * \return          0 if successful, or a MBEDTLS_ERR_X509_ALLOC_FAILED
00577  */
00578 int mbedtls_x509write_crt_set_authority_key_identifier( mbedtls_x509write_cert *ctx );
00579 #endif /* MBEDTLS_SHA1_C */
00580 
00581 /**
00582  * \brief           Set the Key Usage Extension flags
00583  *                  (e.g. MBEDTLS_X509_KU_DIGITAL_SIGNATURE | MBEDTLS_X509_KU_KEY_CERT_SIGN)
00584  *
00585  * \param ctx       CRT context to use
00586  * \param key_usage key usage flags to set
00587  *
00588  * \return          0 if successful, or MBEDTLS_ERR_X509_ALLOC_FAILED
00589  */
00590 int mbedtls_x509write_crt_set_key_usage( mbedtls_x509write_cert *ctx,
00591                                          unsigned int key_usage );
00592 
00593 /**
00594  * \brief           Set the Netscape Cert Type flags
00595  *                  (e.g. MBEDTLS_X509_NS_CERT_TYPE_SSL_CLIENT | MBEDTLS_X509_NS_CERT_TYPE_EMAIL)
00596  *
00597  * \param ctx           CRT context to use
00598  * \param ns_cert_type  Netscape Cert Type flags to set
00599  *
00600  * \return          0 if successful, or MBEDTLS_ERR_X509_ALLOC_FAILED
00601  */
00602 int mbedtls_x509write_crt_set_ns_cert_type( mbedtls_x509write_cert *ctx,
00603                                     unsigned char ns_cert_type );
00604 
00605 /**
00606  * \brief           Free the contents of a CRT write context
00607  *
00608  * \param ctx       CRT context to free
00609  */
00610 void mbedtls_x509write_crt_free( mbedtls_x509write_cert *ctx );
00611 
00612 /**
00613  * \brief           Write a built up certificate to a X509 DER structure
00614  *                  Note: data is written at the end of the buffer! Use the
00615  *                        return value to determine where you should start
00616  *                        using the buffer
00617  *
00618  * \param ctx       certificate to write away
00619  * \param buf       buffer to write to
00620  * \param size      size of the buffer
00621  * \param f_rng     RNG function (for signature, see note)
00622  * \param p_rng     RNG parameter
00623  *
00624  * \return          length of data written if successful, or a specific
00625  *                  error code
00626  *
00627  * \note            f_rng may be NULL if RSA is used for signature and the
00628  *                  signature is made offline (otherwise f_rng is desirable
00629  *                  for countermeasures against timing attacks).
00630  *                  ECDSA signatures always require a non-NULL f_rng.
00631  */
00632 int mbedtls_x509write_crt_der( mbedtls_x509write_cert *ctx, unsigned char *buf, size_t size,
00633                        int (*f_rng)(void *, unsigned char *, size_t),
00634                        void *p_rng );
00635 
00636 #if defined(MBEDTLS_PEM_WRITE_C)
00637 /**
00638  * \brief           Write a built up certificate to a X509 PEM string
00639  *
00640  * \param ctx       certificate to write away
00641  * \param buf       buffer to write to
00642  * \param size      size of the buffer
00643  * \param f_rng     RNG function (for signature, see note)
00644  * \param p_rng     RNG parameter
00645  *
00646  * \return          0 if successful, or a specific error code
00647  *
00648  * \note            f_rng may be NULL if RSA is used for signature and the
00649  *                  signature is made offline (otherwise f_rng is desirable
00650  *                  for countermeasures against timing attacks).
00651  *                  ECDSA signatures always require a non-NULL f_rng.
00652  */
00653 int mbedtls_x509write_crt_pem( mbedtls_x509write_cert *ctx, unsigned char *buf, size_t size,
00654                        int (*f_rng)(void *, unsigned char *, size_t),
00655                        void *p_rng );
00656 #endif /* MBEDTLS_PEM_WRITE_C */
00657 #endif /* MBEDTLS_X509_CRT_WRITE_C */
00658 
00659 #ifdef __cplusplus
00660 }
00661 #endif
00662 
00663 #endif /* mbedtls_x509_crt.h */