/** * \file x509_crt.h * * \brief X.509 certificate parsing and writing */ /* * Copyright (C) 2006-2015, ARM Limited, All Rights Reserved * SPDX-License-Identifier: GPL-2.0 * * 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. * * This file is part of mbed TLS (https://tls.mbed.org) */ #ifndef MBEDTLS_X509_CRT_H #define MBEDTLS_X509_CRT_H #if !defined(MBEDTLS_CONFIG_FILE) #include "config.h" #else #include MBEDTLS_CONFIG_FILE #endif #include "x509.h" #include "x509_crl.h" /** * \addtogroup x509_module * \{ */ #ifdef __cplusplus extern "C" { #endif /** * \name Structures and functions for parsing and writing X.509 certificates * \{ */ /** * Container for an X.509 certificate. The certificate may be chained. */ typedef struct mbedtls_x509_crt { mbedtls_x509_buf raw; /**< The raw certificate data (DER). */ mbedtls_x509_buf tbs; /**< The raw certificate body (DER). The part that is To Be Signed. */ int version; /**< The X.509 version. (1=v1, 2=v2, 3=v3) */ mbedtls_x509_buf serial; /**< Unique id for certificate issued by a specific CA. */ mbedtls_x509_buf sig_oid; /**< Signature algorithm, e.g. sha1RSA */ mbedtls_x509_buf issuer_raw; /**< The raw issuer data (DER). Used for quick comparison. */ mbedtls_x509_buf subject_raw; /**< The raw subject data (DER). Used for quick comparison. */ mbedtls_x509_name issuer; /**< The parsed issuer data (named information object). */ mbedtls_x509_name subject; /**< The parsed subject data (named information object). */ mbedtls_x509_time valid_from; /**< Start time of certificate validity. */ mbedtls_x509_time valid_to; /**< End time of certificate validity. */ mbedtls_pk_context pk; /**< Container for the public key context. */ mbedtls_x509_buf issuer_id; /**< Optional X.509 v2/v3 issuer unique identifier. */ mbedtls_x509_buf subject_id; /**< Optional X.509 v2/v3 subject unique identifier. */ mbedtls_x509_buf v3_ext; /**< Optional X.509 v3 extensions. */ mbedtls_x509_sequence subject_alt_names; /**< Optional list of Subject Alternative Names (Only dNSName supported). */ int ext_types; /**< Bit string containing detected and parsed extensions */ int ca_istrue; /**< Optional Basic Constraint extension value: 1 if this certificate belongs to a CA, 0 otherwise. */ 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+ */ unsigned int key_usage; /**< Optional key usage extension value: See the values in x509.h */ mbedtls_x509_sequence ext_key_usage; /**< Optional list of extended key usage OIDs. */ unsigned char ns_cert_type; /**< Optional Netscape certificate type extension value: See the values in x509.h */ mbedtls_x509_buf sig; /**< Signature: hash of the tbs part signed with the private key. */ mbedtls_md_type_t sig_md; /**< Internal representation of the MD algorithm of the signature algorithm, e.g. MBEDTLS_MD_SHA256 */ mbedtls_pk_type_t sig_pk; /**< Internal representation of the Public Key algorithm of the signature algorithm, e.g. MBEDTLS_PK_RSA */ void *sig_opts; /**< Signature options to be passed to mbedtls_pk_verify_ext(), e.g. for RSASSA-PSS */ struct mbedtls_x509_crt *next; /**< Next certificate in the CA-chain. */ } mbedtls_x509_crt; /** * Build flag from an algorithm/curve identifier (pk, md, ecp) * Since 0 is always XXX_NONE, ignore it. */ #define MBEDTLS_X509_ID_FLAG( id ) ( 1 << ( id - 1 ) ) /** * Security profile for certificate verification. * * All lists are bitfields, built by ORing flags from MBEDTLS_X509_ID_FLAG(). */ typedef struct mbedtls_x509_crt_profile { uint32_t allowed_mds; /**< MDs for signatures */ uint32_t allowed_pks; /**< PK algs for signatures */ uint32_t allowed_curves; /**< Elliptic curves for ECDSA */ uint32_t rsa_min_bitlen; /**< Minimum size for RSA keys */ } mbedtls_x509_crt_profile; #define MBEDTLS_X509_CRT_VERSION_1 0 #define MBEDTLS_X509_CRT_VERSION_2 1 #define MBEDTLS_X509_CRT_VERSION_3 2 #define MBEDTLS_X509_RFC5280_MAX_SERIAL_LEN 32 #define MBEDTLS_X509_RFC5280_UTC_TIME_LEN 15 #if !defined( MBEDTLS_X509_MAX_FILE_PATH_LEN ) #define MBEDTLS_X509_MAX_FILE_PATH_LEN 512 #endif /** * Container for writing a certificate (CRT) */ typedef struct mbedtls_x509write_cert { int version; mbedtls_mpi serial; mbedtls_pk_context *subject_key; mbedtls_pk_context *issuer_key; mbedtls_asn1_named_data *subject; mbedtls_asn1_named_data *issuer; mbedtls_md_type_t md_alg; char not_before[MBEDTLS_X509_RFC5280_UTC_TIME_LEN + 1]; char not_after[MBEDTLS_X509_RFC5280_UTC_TIME_LEN + 1]; mbedtls_asn1_named_data *extensions; } mbedtls_x509write_cert; #if defined(MBEDTLS_X509_CRT_PARSE_C) /** * Default security profile. Should provide a good balance between security * and compatibility with current deployments. */ extern const mbedtls_x509_crt_profile mbedtls_x509_crt_profile_default; /** * Expected next default profile. Recommended for new deployments. * Currently targets a 128-bit security level, except for RSA-2048. */ extern const mbedtls_x509_crt_profile mbedtls_x509_crt_profile_next; /** * NSA Suite B profile. */ extern const mbedtls_x509_crt_profile mbedtls_x509_crt_profile_suiteb; /** * \brief Parse a single DER formatted certificate and add it * to the chained list. * * \param chain points to the start of the chain * \param buf buffer holding the certificate DER data * \param buflen size of the buffer * * \return 0 if successful, or a specific X509 or PEM error code */ int mbedtls_x509_crt_parse_der( mbedtls_x509_crt *chain, const unsigned char *buf, size_t buflen ); /** * \brief Parse one or more certificates and add them * to the chained list. Parses permissively. If some * certificates can be parsed, the result is the number * of failed certificates it encountered. If none complete * correctly, the first error is returned. * * \param chain points to the start of the chain * \param buf buffer holding the certificate data in PEM or DER format * \param buflen size of the buffer * (including the terminating null byte for PEM data) * * \return 0 if all certificates parsed successfully, a positive number * if partly successful or a specific X509 or PEM error code */ int mbedtls_x509_crt_parse( mbedtls_x509_crt *chain, const unsigned char *buf, size_t buflen ); #if defined(MBEDTLS_FS_IO) /** * \brief Load one or more certificates and add them * to the chained list. Parses permissively. If some * certificates can be parsed, the result is the number * of failed certificates it encountered. If none complete * correctly, the first error is returned. * * \param chain points to the start of the chain * \param path filename to read the certificates from * * \return 0 if all certificates parsed successfully, a positive number * if partly successful or a specific X509 or PEM error code */ int mbedtls_x509_crt_parse_file( mbedtls_x509_crt *chain, const char *path ); /** * \brief Load one or more certificate files from a path and add them * to the chained list. Parses permissively. If some * certificates can be parsed, the result is the number * of failed certificates it encountered. If none complete * correctly, the first error is returned. * * \param chain points to the start of the chain * \param path directory / folder to read the certificate files from * * \return 0 if all certificates parsed successfully, a positive number * if partly successful or a specific X509 or PEM error code */ int mbedtls_x509_crt_parse_path( mbedtls_x509_crt *chain, const char *path ); #endif /* MBEDTLS_FS_IO */ /** * \brief Returns an informational string about the * certificate. * * \param buf Buffer to write to * \param size Maximum size of buffer * \param prefix A line prefix * \param crt The X509 certificate to represent * * \return The length of the string written (not including the * terminated nul byte), or a negative error code. */ int mbedtls_x509_crt_info( char *buf, size_t size, const char *prefix, const mbedtls_x509_crt *crt ); /** * \brief Returns an informational string about the * verification status of a certificate. * * \param buf Buffer to write to * \param size Maximum size of buffer * \param prefix A line prefix * \param flags Verification flags created by mbedtls_x509_crt_verify() * * \return The length of the string written (not including the * terminated nul byte), or a negative error code. */ int mbedtls_x509_crt_verify_info( char *buf, size_t size, const char *prefix, uint32_t flags ); /** * \brief Verify the certificate signature * * The verify callback is a user-supplied callback that * can clear / modify / add flags for a certificate. If set, * the verification callback is called for each * certificate in the chain (from the trust-ca down to the * presented crt). The parameters for the callback are: * (void *parameter, mbedtls_x509_crt *crt, int certificate_depth, * int *flags). With the flags representing current flags for * that specific certificate and the certificate depth from * the bottom (Peer cert depth = 0). * * All flags left after returning from the callback * are also returned to the application. The function should * return 0 for anything (including invalid certificates) * other than fatal error, as a non-zero return code * immediately aborts the verification process. For fatal * errors, a specific error code should be used (different * from MBEDTLS_ERR_X509_CERT_VERIFY_FAILED which should not * be returned at this point), or MBEDTLS_ERR_X509_FATAL_ERROR * can be used if no better code is available. * * \note In case verification failed, the results can be displayed * using \c mbedtls_x509_crt_verify_info() * * \note Same as \c mbedtls_x509_crt_verify_with_profile() with the * default security profile. * * \note It is your responsibility to provide up-to-date CRLs for * all trusted CAs. If no CRL is provided for the CA that was * used to sign the certificate, CRL verification is skipped * silently, that is *without* setting any flag. * * \note The \c trust_ca list can contain two types of certificates: * (1) those of trusted root CAs, so that certificates * chaining up to those CAs will be trusted, and (2) * self-signed end-entity certificates to be trusted (for * specific peers you know) - in that case, the self-signed * certificate doesn't need to have the CA bit set. * * \param crt a certificate (chain) to be verified * \param trust_ca the list of trusted CAs (see note above) * \param ca_crl the list of CRLs for trusted CAs (see note above) * \param cn expected Common Name (can be set to * NULL if the CN must not be verified) * \param flags result of the verification * \param f_vrfy verification function * \param p_vrfy verification parameter * * \return 0 (and flags set to 0) if the chain was verified and valid, * MBEDTLS_ERR_X509_CERT_VERIFY_FAILED if the chain was verified * but found to be invalid, in which case *flags will have one * or more MBEDTLS_X509_BADCERT_XXX or MBEDTLS_X509_BADCRL_XXX * flags set, or another error (and flags set to 0xffffffff) * in case of a fatal error encountered during the * verification process. */ int mbedtls_x509_crt_verify( mbedtls_x509_crt *crt, mbedtls_x509_crt *trust_ca, mbedtls_x509_crl *ca_crl, const char *cn, uint32_t *flags, int (*f_vrfy)(void *, mbedtls_x509_crt *, int, uint32_t *), void *p_vrfy ); /** * \brief Verify the certificate signature according to profile * * \note Same as \c mbedtls_x509_crt_verify(), but with explicit * security profile. * * \note The restrictions on keys (RSA minimum size, allowed curves * for ECDSA) apply to all certificates: trusted root, * intermediate CAs if any, and end entity certificate. * * \param crt a certificate (chain) to be verified * \param trust_ca the list of trusted CAs * \param ca_crl the list of CRLs for trusted CAs * \param profile security profile for verification * \param cn expected Common Name (can be set to * NULL if the CN must not be verified) * \param flags result of the verification * \param f_vrfy verification function * \param p_vrfy verification parameter * * \return 0 if successful or MBEDTLS_ERR_X509_CERT_VERIFY_FAILED * in which case *flags will have one or more * MBEDTLS_X509_BADCERT_XXX or MBEDTLS_X509_BADCRL_XXX flags * set, * or another error in case of a fatal error encountered * during the verification process. */ int mbedtls_x509_crt_verify_with_profile( mbedtls_x509_crt *crt, mbedtls_x509_crt *trust_ca, mbedtls_x509_crl *ca_crl, const mbedtls_x509_crt_profile *profile, const char *cn, uint32_t *flags, int (*f_vrfy)(void *, mbedtls_x509_crt *, int, uint32_t *), void *p_vrfy ); #if defined(MBEDTLS_X509_CHECK_KEY_USAGE) /** * \brief Check usage of certificate against keyUsage extension. * * \param crt Leaf certificate used. * \param usage Intended usage(s) (eg MBEDTLS_X509_KU_KEY_ENCIPHERMENT * before using the certificate to perform an RSA key * exchange). * * \note Except for decipherOnly and encipherOnly, a bit set in the * usage argument means this bit MUST be set in the * certificate. For decipherOnly and encipherOnly, it means * that bit MAY be set. * * \return 0 is these uses of the certificate are allowed, * MBEDTLS_ERR_X509_BAD_INPUT_DATA if the keyUsage extension * is present but does not match the usage argument. * * \note You should only call this function on leaf certificates, on * (intermediate) CAs the keyUsage extension is automatically * checked by \c mbedtls_x509_crt_verify(). */ int mbedtls_x509_crt_check_key_usage( const mbedtls_x509_crt *crt, unsigned int usage ); #endif /* MBEDTLS_X509_CHECK_KEY_USAGE) */ #if defined(MBEDTLS_X509_CHECK_EXTENDED_KEY_USAGE) /** * \brief Check usage of certificate against extendedKeyUsage. * * \param crt Leaf certificate used. * \param usage_oid Intended usage (eg MBEDTLS_OID_SERVER_AUTH or * MBEDTLS_OID_CLIENT_AUTH). * \param usage_len Length of usage_oid (eg given by MBEDTLS_OID_SIZE()). * * \return 0 if this use of the certificate is allowed, * MBEDTLS_ERR_X509_BAD_INPUT_DATA if not. * * \note Usually only makes sense on leaf certificates. */ int mbedtls_x509_crt_check_extended_key_usage( const mbedtls_x509_crt *crt, const char *usage_oid, size_t usage_len ); #endif /* MBEDTLS_X509_CHECK_EXTENDED_KEY_USAGE */ #if defined(MBEDTLS_X509_CRL_PARSE_C) /** * \brief Verify the certificate revocation status * * \param crt a certificate to be verified * \param crl the CRL to verify against * * \return 1 if the certificate is revoked, 0 otherwise * */ int mbedtls_x509_crt_is_revoked( const mbedtls_x509_crt *crt, const mbedtls_x509_crl *crl ); #endif /* MBEDTLS_X509_CRL_PARSE_C */ /** * \brief Initialize a certificate (chain) * * \param crt Certificate chain to initialize */ void mbedtls_x509_crt_init( mbedtls_x509_crt *crt ); /** * \brief Unallocate all certificate data * * \param crt Certificate chain to free */ void mbedtls_x509_crt_free( mbedtls_x509_crt *crt ); #endif /* MBEDTLS_X509_CRT_PARSE_C */ /* \} name */ /* \} addtogroup x509_module */ #if defined(MBEDTLS_X509_CRT_WRITE_C) /** * \brief Initialize a CRT writing context * * \param ctx CRT context to initialize */ void mbedtls_x509write_crt_init( mbedtls_x509write_cert *ctx ); /** * \brief Set the verion for a Certificate * Default: MBEDTLS_X509_CRT_VERSION_3 * * \param ctx CRT context to use * \param version version to set (MBEDTLS_X509_CRT_VERSION_1, MBEDTLS_X509_CRT_VERSION_2 or * MBEDTLS_X509_CRT_VERSION_3) */ void mbedtls_x509write_crt_set_version( mbedtls_x509write_cert *ctx, int version ); /** * \brief Set the serial number for a Certificate. * * \param ctx CRT context to use * \param serial serial number to set * * \return 0 if successful */ int mbedtls_x509write_crt_set_serial( mbedtls_x509write_cert *ctx, const mbedtls_mpi *serial ); /** * \brief Set the validity period for a Certificate * Timestamps should be in string format for UTC timezone * i.e. "YYYYMMDDhhmmss" * e.g. "20131231235959" for December 31st 2013 * at 23:59:59 * * \param ctx CRT context to use * \param not_before not_before timestamp * \param not_after not_after timestamp * * \return 0 if timestamp was parsed successfully, or * a specific error code */ int mbedtls_x509write_crt_set_validity( mbedtls_x509write_cert *ctx, const char *not_before, const char *not_after ); /** * \brief Set the issuer name for a Certificate * Issuer names should contain a comma-separated list * of OID types and values: * e.g. "C=UK,O=ARM,CN=mbed TLS CA" * * \param ctx CRT context to use * \param issuer_name issuer name to set * * \return 0 if issuer name was parsed successfully, or * a specific error code */ int mbedtls_x509write_crt_set_issuer_name( mbedtls_x509write_cert *ctx, const char *issuer_name ); /** * \brief Set the subject name for a Certificate * Subject names should contain a comma-separated list * of OID types and values: * e.g. "C=UK,O=ARM,CN=mbed TLS Server 1" * * \param ctx CRT context to use * \param subject_name subject name to set * * \return 0 if subject name was parsed successfully, or * a specific error code */ int mbedtls_x509write_crt_set_subject_name( mbedtls_x509write_cert *ctx, const char *subject_name ); /** * \brief Set the subject public key for the certificate * * \param ctx CRT context to use * \param key public key to include */ void mbedtls_x509write_crt_set_subject_key( mbedtls_x509write_cert *ctx, mbedtls_pk_context *key ); /** * \brief Set the issuer key used for signing the certificate * * \param ctx CRT context to use * \param key private key to sign with */ void mbedtls_x509write_crt_set_issuer_key( mbedtls_x509write_cert *ctx, mbedtls_pk_context *key ); /** * \brief Set the MD algorithm to use for the signature * (e.g. MBEDTLS_MD_SHA1) * * \param ctx CRT context to use * \param md_alg MD algorithm to use */ void mbedtls_x509write_crt_set_md_alg( mbedtls_x509write_cert *ctx, mbedtls_md_type_t md_alg ); /** * \brief Generic function to add to or replace an extension in the * CRT * * \param ctx CRT context to use * \param oid OID of the extension * \param oid_len length of the OID * \param critical if the extension is critical (per the RFC's definition) * \param val value of the extension OCTET STRING * \param val_len length of the value data * * \return 0 if successful, or a MBEDTLS_ERR_X509_ALLOC_FAILED */ int mbedtls_x509write_crt_set_extension( mbedtls_x509write_cert *ctx, const char *oid, size_t oid_len, int critical, const unsigned char *val, size_t val_len ); /** * \brief Set the basicConstraints extension for a CRT * * \param ctx CRT context to use * \param is_ca is this a CA certificate * \param max_pathlen maximum length of certificate chains below this * certificate (only for CA certificates, -1 is * inlimited) * * \return 0 if successful, or a MBEDTLS_ERR_X509_ALLOC_FAILED */ int mbedtls_x509write_crt_set_basic_constraints( mbedtls_x509write_cert *ctx, int is_ca, int max_pathlen ); #if defined(MBEDTLS_SHA1_C) /** * \brief Set the subjectKeyIdentifier extension for a CRT * Requires that mbedtls_x509write_crt_set_subject_key() has been * called before * * \param ctx CRT context to use * * \return 0 if successful, or a MBEDTLS_ERR_X509_ALLOC_FAILED */ int mbedtls_x509write_crt_set_subject_key_identifier( mbedtls_x509write_cert *ctx ); /** * \brief Set the authorityKeyIdentifier extension for a CRT * Requires that mbedtls_x509write_crt_set_issuer_key() has been * called before * * \param ctx CRT context to use * * \return 0 if successful, or a MBEDTLS_ERR_X509_ALLOC_FAILED */ int mbedtls_x509write_crt_set_authority_key_identifier( mbedtls_x509write_cert *ctx ); #endif /* MBEDTLS_SHA1_C */ /** * \brief Set the Key Usage Extension flags * (e.g. MBEDTLS_X509_KU_DIGITAL_SIGNATURE | MBEDTLS_X509_KU_KEY_CERT_SIGN) * * \param ctx CRT context to use * \param key_usage key usage flags to set * * \return 0 if successful, or MBEDTLS_ERR_X509_ALLOC_FAILED */ int mbedtls_x509write_crt_set_key_usage( mbedtls_x509write_cert *ctx, unsigned int key_usage ); /** * \brief Set the Netscape Cert Type flags * (e.g. MBEDTLS_X509_NS_CERT_TYPE_SSL_CLIENT | MBEDTLS_X509_NS_CERT_TYPE_EMAIL) * * \param ctx CRT context to use * \param ns_cert_type Netscape Cert Type flags to set * * \return 0 if successful, or MBEDTLS_ERR_X509_ALLOC_FAILED */ int mbedtls_x509write_crt_set_ns_cert_type( mbedtls_x509write_cert *ctx, unsigned char ns_cert_type ); /** * \brief Free the contents of a CRT write context * * \param ctx CRT context to free */ void mbedtls_x509write_crt_free( mbedtls_x509write_cert *ctx ); /** * \brief Write a built up certificate to a X509 DER structure * Note: data is written at the end of the buffer! Use the * return value to determine where you should start * using the buffer * * \param ctx certificate to write away * \param buf buffer to write to * \param size size of the buffer * \param f_rng RNG function (for signature, see note) * \param p_rng RNG parameter * * \return length of data written if successful, or a specific * error code * * \note f_rng may be NULL if RSA is used for signature and the * signature is made offline (otherwise f_rng is desirable * for countermeasures against timing attacks). * ECDSA signatures always require a non-NULL f_rng. */ int mbedtls_x509write_crt_der( mbedtls_x509write_cert *ctx, unsigned char *buf, size_t size, int (*f_rng)(void *, unsigned char *, size_t), void *p_rng ); #if defined(MBEDTLS_PEM_WRITE_C) /** * \brief Write a built up certificate to a X509 PEM string * * \param ctx certificate to write away * \param buf buffer to write to * \param size size of the buffer * \param f_rng RNG function (for signature, see note) * \param p_rng RNG parameter * * \return 0 if successful, or a specific error code * * \note f_rng may be NULL if RSA is used for signature and the * signature is made offline (otherwise f_rng is desirable * for countermeasures against timing attacks). * ECDSA signatures always require a non-NULL f_rng. */ int mbedtls_x509write_crt_pem( mbedtls_x509write_cert *ctx, unsigned char *buf, size_t size, int (*f_rng)(void *, unsigned char *, size_t), void *p_rng ); #endif /* MBEDTLS_PEM_WRITE_C */ #endif /* MBEDTLS_X509_CRT_WRITE_C */ #ifdef __cplusplus } #endif #endif /* mbedtls_x509_crt.h */