X.509 module#

The X.509 module provides X.509 support for reading, writing and verification of certificates.

In summary:

  • X.509 certificate (CRT) reading (see mbedtls_x509_crt_parse(), mbedtls_x509_crt_parse_der(), mbedtls_x509_crt_parse_file()).

  • X.509 certificate revocation list (CRL) reading (see mbedtls_x509_crl_parse(), mbedtls_x509_crl_parse_der(), and mbedtls_x509_crl_parse_file()).

  • X.509 certificate signature verification (see mbedtls_x509_crt_verify() and mbedtls_x509_crt_verify_with_profile().

  • X.509 certificate writing and certificate request writing (see mbedtls_x509write_crt_der() and mbedtls_x509write_csr_der()).

This module can be used to build a certificate authority (CA) chain and verify its signature. It is also used to generate Certificate Signing Requests and X.509 certificates just as a CA would do.

Modules#

mbedtls_x509_crt

mbedtls_x509_crt_profile

mbedtls_x509write_cert

mbedtls_x509_crt_verify_chain_item

mbedtls_x509_crt_verify_chain

mbedtls_x509_crl_entry

mbedtls_x509_crl

mbedtls_x509_csr

mbedtls_x509write_csr

mbedtls_x509_authority

mbedtls_x509_time

mbedtls_x509_san_other_name

mbedtls_x509_subject_alternative_name

mbedtls_x509_san_list

Structures and functions for parsing and writing X.509 certificates#

typedef int(*
mbedtls_x509_crt_ext_cb_t)(void *p_ctx, mbedtls_x509_crt const *crt, mbedtls_x509_buf const *oid, int critical, const unsigned char *p, const unsigned char *end)

The type of certificate extension callbacks.

typedef int(*
mbedtls_x509_crt_ca_cb_t)(void *p_ctx, mbedtls_x509_crt const *child, mbedtls_x509_crt **candidate_cas)

The type of trusted certificate callbacks.

Expected next default profile.

Empty profile that allows nothing.

int
mbedtls_x509write_crt_set_subject_alternative_name(mbedtls_x509write_cert *ctx, const mbedtls_x509_san_list *san_list)

Set Subject Alternative Name.

int
mbedtls_x509_crt_parse_der(mbedtls_x509_crt *chain, const unsigned char *buf, size_t buflen)

Parse a single DER formatted certificate and add it to the end of the provided chained list.

int
mbedtls_x509_crt_parse_der_with_ext_cb(mbedtls_x509_crt *chain, const unsigned char *buf, size_t buflen, int make_copy, mbedtls_x509_crt_ext_cb_t cb, void *p_ctx)

Parse a single DER formatted certificate and add it to the end of the provided chained list.

int
mbedtls_x509_crt_parse_der_nocopy(mbedtls_x509_crt *chain, const unsigned char *buf, size_t buflen)

Parse a single DER formatted certificate and add it to the end of the provided chained list.

int
mbedtls_x509_crt_parse(mbedtls_x509_crt *chain, const unsigned char *buf, size_t buflen)

Parse one DER-encoded or one or more concatenated PEM-encoded certificates and add them to the chained list.

int
mbedtls_x509_crt_info(char *buf, size_t size, const char *prefix, const mbedtls_x509_crt *crt)

Returns an informational string about the certificate.

int
mbedtls_x509_crt_verify_info(char *buf, size_t size, const char *prefix, uint32_t flags)

Returns an informational string about the verification status of a certificate.

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)

Verify a chain of certificates.

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)

Verify a chain of certificates with respect to a configurable security profile.

int
mbedtls_x509_crt_verify_restartable(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, mbedtls_x509_crt_restart_ctx *rs_ctx)

Restartable version of mbedtls_crt_verify_with_profile()

int
mbedtls_x509_crt_check_key_usage(const mbedtls_x509_crt *crt, unsigned int usage)

Check usage of certificate against keyUsage extension.

int
mbedtls_x509_crt_check_extended_key_usage(const mbedtls_x509_crt *crt, const char *usage_oid, size_t usage_len)

Check usage of certificate against extendedKeyUsage.

int
mbedtls_x509_crt_is_revoked(const mbedtls_x509_crt *crt, const mbedtls_x509_crl *crl)

Verify the certificate revocation status.

void
mbedtls_x509_crt_init(mbedtls_x509_crt *crt)

Initialize a certificate (chain)

void
mbedtls_x509_crt_free(mbedtls_x509_crt *crt)

Unallocate all certificate data.

int
mbedtls_x509_crt_has_ext_type(const mbedtls_x509_crt *ctx, int ext_type)

Query certificate for given extension type.

#define
MBEDTLS_X509_ID_FLAG (id)

Build flag from an algorithm/curve identifier (pk, md, ecp) Since 0 is always XXX_NONE, ignore it.

#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 20
#define
MBEDTLS_X509_RFC5280_UTC_TIME_LEN 15
#define
MBEDTLS_X509_MAX_FILE_PATH_LEN 512
#define
MBEDTLS_X509_CRT_ERROR_INFO_LIST
#define
MBEDTLS_X509_MAX_VERIFY_CHAIN_SIZE (MBEDTLS_X509_MAX_INTERMEDIATE_CA + 2)

Max size of verification chain: end-entity + intermediates + trusted root.

Structures for parsing X.509 certificates, CRLs and CSRs#

Type-length-value structure that allows for ASN1 using DER.

Container for ASN1 bit strings.

Container for ASN1 named information objects.

Container for a sequence of ASN.1 items.

Structures and functions for parsing CRLs#

int
mbedtls_x509_crl_parse_der(mbedtls_x509_crl *chain, const unsigned char *buf, size_t buflen)

Parse a DER-encoded CRL and append it to the chained list.

int
mbedtls_x509_crl_parse(mbedtls_x509_crl *chain, const unsigned char *buf, size_t buflen)

Parse one or more CRLs and append them to the chained list.

int
mbedtls_x509_crl_info(char *buf, size_t size, const char *prefix, const mbedtls_x509_crl *crl)

Returns an informational string about the CRL.

void
mbedtls_x509_crl_init(mbedtls_x509_crl *crl)

Initialize a CRL (chain)

void
mbedtls_x509_crl_free(mbedtls_x509_crl *crl)

Unallocate all CRL data.

Structures and functions for X.509 Certificate Signing Requests (CSR)#

int
mbedtls_x509_csr_parse_der(mbedtls_x509_csr *csr, const unsigned char *buf, size_t buflen)

Load a Certificate Signing Request (CSR) in DER format.

int
mbedtls_x509_csr_parse(mbedtls_x509_csr *csr, const unsigned char *buf, size_t buflen)

Load a Certificate Signing Request (CSR), DER or PEM format.

int
mbedtls_x509_csr_info(char *buf, size_t size, const char *prefix, const mbedtls_x509_csr *csr)

Returns an informational string about the CSR.

void
mbedtls_x509_csr_init(mbedtls_x509_csr *csr)

Initialize a CSR.

void
mbedtls_x509_csr_free(mbedtls_x509_csr *csr)

Unallocate all CSR data.

X509 Error codes#

#define
MBEDTLS_ERR_X509_FEATURE_UNAVAILABLE -0x2080

Unavailable feature, e.g.

#define
MBEDTLS_ERR_X509_UNKNOWN_OID -0x2100

Requested OID is unknown.

#define
MBEDTLS_ERR_X509_INVALID_FORMAT -0x2180

The CRT/CRL/CSR format is invalid, e.g.

#define
MBEDTLS_ERR_X509_INVALID_VERSION -0x2200

The CRT/CRL/CSR version element is invalid.

#define
MBEDTLS_ERR_X509_INVALID_SERIAL -0x2280

The serial tag or value is invalid.

#define
MBEDTLS_ERR_X509_INVALID_ALG -0x2300

The algorithm tag or value is invalid.

#define
MBEDTLS_ERR_X509_INVALID_NAME -0x2380

The name tag or value is invalid.

#define
MBEDTLS_ERR_X509_INVALID_DATE -0x2400

The date tag or value is invalid.

#define
MBEDTLS_ERR_X509_INVALID_SIGNATURE -0x2480

The signature tag or value invalid.

#define
MBEDTLS_ERR_X509_INVALID_EXTENSIONS -0x2500

The extension tag or value is invalid.

#define
MBEDTLS_ERR_X509_UNKNOWN_VERSION -0x2580

CRT/CRL/CSR has an unsupported version number.

#define
MBEDTLS_ERR_X509_UNKNOWN_SIG_ALG -0x2600

Signature algorithm (oid) is unsupported.

#define
MBEDTLS_ERR_X509_SIG_MISMATCH -0x2680

Signature algorithms do not match.

#define
MBEDTLS_ERR_X509_CERT_VERIFY_FAILED -0x2700

Certificate verification failed, e.g.

#define
MBEDTLS_ERR_X509_CERT_UNKNOWN_FORMAT -0x2780

Format not recognized as DER or PEM.

#define
MBEDTLS_ERR_X509_BAD_INPUT_DATA -0x2800

Input invalid.

#define
MBEDTLS_ERR_X509_ALLOC_FAILED -0x2880

Allocation of memory failed.

#define
MBEDTLS_ERR_X509_FILE_IO_ERROR -0x2900

Read/write of file failed.

#define
MBEDTLS_ERR_X509_BUFFER_TOO_SMALL -0x2980

Destination buffer is too small.

#define
MBEDTLS_ERR_X509_FATAL_ERROR -0x3000

A fatal error occurred, eg the chain is too long or the vrfy callback failed.

X509 Verify codes#

#define
MBEDTLS_X509_BADCERT_EXPIRED 0x01

The certificate validity has expired.

#define
MBEDTLS_X509_BADCERT_REVOKED 0x02

The certificate has been revoked (is on a CRL).

#define
MBEDTLS_X509_BADCERT_CN_MISMATCH 0x04

The certificate Common Name (CN) does not match with the expected CN.

#define
MBEDTLS_X509_BADCERT_NOT_TRUSTED 0x08

The certificate is not correctly signed by the trusted CA.

#define
MBEDTLS_X509_BADCRL_NOT_TRUSTED 0x10

The CRL is not correctly signed by the trusted CA.

#define
MBEDTLS_X509_BADCRL_EXPIRED 0x20

The CRL is expired.

#define
MBEDTLS_X509_BADCERT_MISSING 0x40

Certificate was missing.

#define
MBEDTLS_X509_BADCERT_SKIP_VERIFY 0x80

Certificate verification was skipped.

#define
MBEDTLS_X509_BADCERT_OTHER 0x0100

Other reason (can be used by verify callback)

#define
MBEDTLS_X509_BADCERT_FUTURE 0x0200

The certificate validity starts in the future.

#define
MBEDTLS_X509_BADCRL_FUTURE 0x0400

The CRL is from the future.

#define
MBEDTLS_X509_BADCERT_KEY_USAGE 0x0800

Usage does not match the keyUsage extension.

#define
MBEDTLS_X509_BADCERT_EXT_KEY_USAGE 0x1000

Usage does not match the extendedKeyUsage extension.

#define
MBEDTLS_X509_BADCERT_NS_CERT_TYPE 0x2000

Usage does not match the nsCertType extension.

#define
MBEDTLS_X509_BADCERT_BAD_MD 0x4000

The certificate is signed with an unacceptable hash.

#define
MBEDTLS_X509_BADCERT_BAD_PK 0x8000

The certificate is signed with an unacceptable PK alg (eg RSA vs ECDSA).

#define
MBEDTLS_X509_BADCERT_BAD_KEY 0x010000

The certificate is signed with an unacceptable key (eg bad curve, RSA too short).

#define
MBEDTLS_X509_BADCRL_BAD_MD 0x020000

The CRL is signed with an unacceptable hash.

#define
MBEDTLS_X509_BADCRL_BAD_PK 0x040000

The CRL is signed with an unacceptable PK alg (eg RSA vs ECDSA).

#define
MBEDTLS_X509_BADCRL_BAD_KEY 0x080000

The CRL is signed with an unacceptable key (eg bad curve, RSA too short).

Functions#

void
mbedtls_x509write_crt_init(mbedtls_x509write_cert *ctx)

Initialize a CRT writing context.

void
mbedtls_x509write_crt_set_version(mbedtls_x509write_cert *ctx, int version)

Set the version for a Certificate Default: MBEDTLS_X509_CRT_VERSION_3.

int MBEDTLS_DEPRECATED
mbedtls_x509write_crt_set_serial(mbedtls_x509write_cert *ctx, const mbedtls_mpi *serial)

Set the serial number for a Certificate.

int
mbedtls_x509write_crt_set_serial_raw(mbedtls_x509write_cert *ctx, unsigned char *serial, size_t serial_len)

Set the serial number for a Certificate.

int
mbedtls_x509write_crt_set_validity(mbedtls_x509write_cert *ctx, const char *not_before, const char *not_after)

Set the validity period for a Certificate Timestamps should be in string format for UTC timezone i.e.

int
mbedtls_x509write_crt_set_issuer_name(mbedtls_x509write_cert *ctx, const char *issuer_name)

Set the issuer name for a Certificate Issuer names should contain a comma-separated list of OID types and values: e.g.

int
mbedtls_x509write_crt_set_subject_name(mbedtls_x509write_cert *ctx, const char *subject_name)

Set the subject name for a Certificate Subject names should contain a comma-separated list of OID types and values: e.g.

void
mbedtls_x509write_crt_set_subject_key(mbedtls_x509write_cert *ctx, mbedtls_pk_context *key)

Set the subject public key for the certificate.

void
mbedtls_x509write_crt_set_issuer_key(mbedtls_x509write_cert *ctx, mbedtls_pk_context *key)

Set the issuer key used for signing the certificate.

void
mbedtls_x509write_crt_set_md_alg(mbedtls_x509write_cert *ctx, mbedtls_md_type_t md_alg)

Set the MD algorithm to use for the signature (e.g.

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)

Generic function to add to or replace an extension in the CRT.

int
mbedtls_x509write_crt_set_basic_constraints(mbedtls_x509write_cert *ctx, int is_ca, int max_pathlen)

Set the basicConstraints extension for a CRT.

int
mbedtls_x509write_crt_set_key_usage(mbedtls_x509write_cert *ctx, unsigned int key_usage)

Set the Key Usage Extension flags (e.g.

int
mbedtls_x509write_crt_set_ext_key_usage(mbedtls_x509write_cert *ctx, const mbedtls_asn1_sequence *exts)

Set the Extended Key Usage Extension (e.g.

int
mbedtls_x509write_crt_set_ns_cert_type(mbedtls_x509write_cert *ctx, unsigned char ns_cert_type)

Set the Netscape Cert Type flags (e.g.

void
mbedtls_x509write_crt_free(mbedtls_x509write_cert *ctx)

Free the contents of a CRT write context.

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)

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.

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)

Write a built up certificate to a X509 PEM string.

void
mbedtls_x509write_csr_init(mbedtls_x509write_csr *ctx)

Initialize a CSR context.

int
mbedtls_x509write_csr_set_subject_name(mbedtls_x509write_csr *ctx, const char *subject_name)

Set the subject name for a CSR Subject names should contain a comma-separated list of OID types and values: e.g.

void
mbedtls_x509write_csr_set_key(mbedtls_x509write_csr *ctx, mbedtls_pk_context *key)

Set the key for a CSR (public key will be included, private key used to sign the CSR when writing it)

void
mbedtls_x509write_csr_set_md_alg(mbedtls_x509write_csr *ctx, mbedtls_md_type_t md_alg)

Set the MD algorithm to use for the signature (e.g.

int
mbedtls_x509write_csr_set_key_usage(mbedtls_x509write_csr *ctx, unsigned char key_usage)

Set the Key Usage Extension flags (e.g.

int
mbedtls_x509write_csr_set_subject_alternative_name(mbedtls_x509write_csr *ctx, const mbedtls_x509_san_list *san_list)

Set Subject Alternative Name.

int
mbedtls_x509write_csr_set_ns_cert_type(mbedtls_x509write_csr *ctx, unsigned char ns_cert_type)

Set the Netscape Cert Type flags (e.g.

int
mbedtls_x509write_csr_set_extension(mbedtls_x509write_csr *ctx, const char *oid, size_t oid_len, int critical, const unsigned char *val, size_t val_len)

Generic function to add to or replace an extension in the CSR.

void
mbedtls_x509write_csr_free(mbedtls_x509write_csr *ctx)

Free the contents of a CSR context.

int
mbedtls_x509write_csr_der(mbedtls_x509write_csr *ctx, unsigned char *buf, size_t size, int(*f_rng)(void *, unsigned char *, size_t), void *p_rng)

Write a CSR (Certificate Signing Request) to a 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.

int
mbedtls_x509write_csr_pem(mbedtls_x509write_csr *ctx, unsigned char *buf, size_t size, int(*f_rng)(void *, unsigned char *, size_t), void *p_rng)

Write a CSR (Certificate Signing Request) to a PEM string.

int
mbedtls_x509_dn_gets(char *buf, size_t size, const mbedtls_x509_name *dn)

Store the certificate DN in printable form into buf; no more than size characters will be written.

mbedtls_x509_dn_get_next(mbedtls_x509_name *dn)

Return the next relative DN in an X509 name.

int
mbedtls_x509_serial_gets(char *buf, size_t size, const mbedtls_x509_buf *serial)

Store the certificate serial in printable form into buf; no more than size characters will be written.

int
mbedtls_x509_time_cmp(const mbedtls_x509_time *t1, const mbedtls_x509_time *t2)

Compare pair of mbedtls_x509_time.

int
mbedtls_x509_time_is_past(const mbedtls_x509_time *to)

Check a given mbedtls_x509_time against the system time and tell if it's in the past.

int
mbedtls_x509_time_is_future(const mbedtls_x509_time *from)

Check a given mbedtls_x509_time against the system time and tell if it's in the future.

int
mbedtls_x509_parse_subject_alt_name(const mbedtls_x509_buf *san_buf, mbedtls_x509_subject_alternative_name *san)

This function parses an item in the SubjectAlternativeNames extension.

void
mbedtls_x509_free_subject_alt_name(mbedtls_x509_subject_alternative_name *san)

Unallocate all data related to subject alternative name.

Macros#

#define
MBEDTLS_X509_MAX_INTERMEDIATE_CA 8

Maximum number of intermediate CAs in a verification chain.

Structures and functions for parsing and writing X.509 certificates Documentation#

mbedtls_x509_crt_restart_ctx#

typedef void mbedtls_x509_crt_restart_ctx

mbedtls_x509_crt_ext_cb_t#

typedef int(* mbedtls_x509_crt_ext_cb_t) (void *p_ctx, mbedtls_x509_crt const *crt, mbedtls_x509_buf const *oid, int critical, const unsigned char *p, const unsigned char *end) )(void *p_ctx, mbedtls_x509_crt const *crt, mbedtls_x509_buf const *oid, int critical, const unsigned char *p, const unsigned char *end)

The type of certificate extension callbacks.

Parameters
TypeDirectionArgument NameDescription
N/Ap_ctx

An opaque context passed to the callback.

N/Acrt

The certificate being parsed.

N/Aoid

The OID of the extension.

N/Acritical

Whether the extension is critical.

N/Ap

Pointer to the start of the extension value (the content of the OCTET STRING).

N/Aend

End of extension value.

            Callbacks of this type are passed to and used by the
            mbedtls_x509_crt_parse_der_with_ext_cb() routine when
            it encounters either an unsupported extension or a
            "certificate policies" extension containing any
            unsupported certificate policies.
            Future versions of the library may invoke the callback
            in other cases, if and when the need arises.

Note

Returns

  • 0 on success.

  • A negative error code on failure.


mbedtls_x509_crt_ca_cb_t#

typedef int(* mbedtls_x509_crt_ca_cb_t) (void *p_ctx, mbedtls_x509_crt const *child, mbedtls_x509_crt **candidate_cas) )(void *p_ctx, mbedtls_x509_crt const *child, mbedtls_x509_crt **candidate_cas)

The type of trusted certificate callbacks.

Parameters
TypeDirectionArgument NameDescription
N/Ap_ctx

An opaque context passed to the callback.

N/Achild

The certificate for which to search a potential signer. This will point to a readable certificate.

N/Acandidate_cas

The address at which to store the address of the first entry in the generated linked list of candidate signers. This will not be NULL.

                 Callbacks of this type are passed to and used by the CRT
                 verification routine mbedtls_x509_crt_verify_with_ca_cb()
                 when looking for trusted signers of a given certificate.

                 On success, the callback returns a list of trusted
                 certificates to be considered as potential signers
                 for the input certificate.

Note

  • The callback must only return a non-zero value on a fatal error. If, in contrast, the search for a potential signer completes without a single candidate, the callback must return 0 and set *candidate_cas to NULL.

Returns

  • 0 on success. In this case, *candidate_cas points to a heap-allocated linked list of instances of mbedtls_x509_crt, and ownership of this list is passed to the caller.

  • A negative error code on failure.


mbedtls_x509_crt_profile_default#

const mbedtls_x509_crt_profile mbedtls_x509_crt_profile_default

Default security profile.

Should provide a good balance between security and compatibility with current deployments.

This profile permits:

  • SHA2 hashes with at least 256 bits: SHA-256, SHA-384, SHA-512.

  • Elliptic curves with 255 bits and above except secp256k1.

  • RSA with 2048 bits and above.

New minor versions of Mbed TLS may extend this profile, for example if new algorithms are added to the library. New minor versions of Mbed TLS will not reduce this profile unless serious security concerns require it.


mbedtls_x509_crt_profile_next#

const mbedtls_x509_crt_profile mbedtls_x509_crt_profile_next

Expected next default profile.

Recommended for new deployments. Currently targets a 128-bit security level, except for allowing RSA-2048. This profile may change at any time.


mbedtls_x509_crt_profile_suiteb#

const mbedtls_x509_crt_profile mbedtls_x509_crt_profile_suiteb

NSA Suite B profile.


mbedtls_x509_crt_profile_none#

const mbedtls_x509_crt_profile mbedtls_x509_crt_profile_none

Empty profile that allows nothing.

Useful as a basis for constructing custom profiles.


mbedtls_x509write_crt_set_subject_alternative_name#

int mbedtls_x509write_crt_set_subject_alternative_name (mbedtls_x509write_cert * ctx, const mbedtls_x509_san_list * san_list)

Set Subject Alternative Name.

Parameters
TypeDirectionArgument NameDescription
mbedtls_x509write_cert *N/Actx

Certificate context to use

const mbedtls_x509_san_list *N/Asan_list

List of SAN values

Returns

  • 0 if successful, or MBEDTLS_ERR_X509_ALLOC_FAILED

Note

  • "dnsName", "uniformResourceIdentifier", "IP address", "otherName", and "DirectoryName", as defined in RFC 5280, are supported.


mbedtls_x509_crt_parse_der#

int mbedtls_x509_crt_parse_der (mbedtls_x509_crt * chain, const unsigned char * buf, size_t buflen)

Parse a single DER formatted certificate and add it to the end of the provided chained list.

Parameters
TypeDirectionArgument NameDescription
mbedtls_x509_crt *N/Achain

The pointer to the start of the CRT chain to attach to. When parsing the first CRT in a chain, this should point to an instance of mbedtls_x509_crt initialized through mbedtls_x509_crt_init().

const unsigned char *N/Abuf

The buffer holding the DER encoded certificate.

size_tN/Abuflen

The size in Bytes of buf.

Note

  • If #MBEDTLS_USE_PSA_CRYPTO is enabled, the PSA crypto subsystem must have been initialized by calling psa_crypto_init() before calling this function.

Note

  • This function makes an internal copy of the CRT buffer buf. In particular, buf may be destroyed or reused after this call returns. To avoid duplicating the CRT buffer (at the cost of stricter lifetime constraints), use mbedtls_x509_crt_parse_der_nocopy() instead.

Returns

  • 0 if successful.

  • A negative error code on failure.


mbedtls_x509_crt_parse_der_with_ext_cb#

int mbedtls_x509_crt_parse_der_with_ext_cb (mbedtls_x509_crt * chain, const unsigned char * buf, size_t buflen, int make_copy, mbedtls_x509_crt_ext_cb_t cb, void * p_ctx)

Parse a single DER formatted certificate and add it to the end of the provided chained list.

Parameters
TypeDirectionArgument NameDescription
mbedtls_x509_crt *N/Achain

The pointer to the start of the CRT chain to attach to. When parsing the first CRT in a chain, this should point to an instance of mbedtls_x509_crt initialized through mbedtls_x509_crt_init().

const unsigned char *N/Abuf

The buffer holding the DER encoded certificate.

size_tN/Abuflen

The size in Bytes of buf.

intN/Amake_copy

When not zero this function makes an internal copy of the CRT buffer buf. In particular, buf may be destroyed or reused after this call returns. When zero this function avoids duplicating the CRT buffer by taking temporary ownership thereof until the CRT is destroyed (like mbedtls_x509_crt_parse_der_nocopy())

mbedtls_x509_crt_ext_cb_tN/Acb

A callback invoked for every unsupported certificate extension.

void *N/Ap_ctx

An opaque context passed to the callback.

Note

  • If #MBEDTLS_USE_PSA_CRYPTO is enabled, the PSA crypto subsystem must have been initialized by calling psa_crypto_init() before calling this function.

Note

  • This call is functionally equivalent to mbedtls_x509_crt_parse_der(), and/or mbedtls_x509_crt_parse_der_nocopy() but it calls the callback with every unsupported certificate extension and additionally the "certificate policies" extension if it contains any unsupported certificate policies. The callback must return a negative error code if it does not know how to handle such an extension. When the callback fails to parse a critical extension mbedtls_x509_crt_parse_der_with_ext_cb() also fails. When the callback fails to parse a non critical extension mbedtls_x509_crt_parse_der_with_ext_cb() simply skips the extension and continues parsing. Future versions of the library may invoke the callback in other cases, if and when the need arises.

Returns

  • 0 if successful.

  • A negative error code on failure.


mbedtls_x509_crt_parse_der_nocopy#

int mbedtls_x509_crt_parse_der_nocopy (mbedtls_x509_crt * chain, const unsigned char * buf, size_t buflen)

Parse a single DER formatted certificate and add it to the end of the provided chained list.

Parameters
TypeDirectionArgument NameDescription
mbedtls_x509_crt *N/Achain

The pointer to the start of the CRT chain to attach to. When parsing the first CRT in a chain, this should point to an instance of mbedtls_x509_crt initialized through mbedtls_x509_crt_init().

const unsigned char *N/Abuf

The address of the readable buffer holding the DER encoded certificate to use. On success, this buffer must be retained and not be changed for the lifetime of the CRT chain chain, that is, until chain is destroyed through a call to mbedtls_x509_crt_free().

size_tN/Abuflen

The size in Bytes of buf.

This is a variant of mbedtls_x509_crt_parse_der() which takes temporary ownership of the CRT buffer until the CRT is destroyed.

Note

  • If #MBEDTLS_USE_PSA_CRYPTO is enabled, the PSA crypto subsystem must have been initialized by calling psa_crypto_init() before calling this function.

Note

  • This call is functionally equivalent to mbedtls_x509_crt_parse_der(), but it avoids creating a copy of the input buffer at the cost of stronger lifetime constraints. This is useful in constrained environments where duplication of the CRT cannot be tolerated.

Returns

  • 0 if successful.

  • A negative error code on failure.


mbedtls_x509_crt_parse#

int mbedtls_x509_crt_parse (mbedtls_x509_crt * chain, const unsigned char * buf, size_t buflen)

Parse one DER-encoded or one or more concatenated PEM-encoded certificates and add them to the chained list.

Parameters
TypeDirectionArgument NameDescription
mbedtls_x509_crt *N/Achain

The chain to which to add the parsed certificates.

const unsigned char *N/Abuf

The buffer holding the certificate data in PEM or DER format. For certificates in PEM encoding, this may be a concatenation of multiple certificates; for DER encoding, the buffer must comprise exactly one certificate.

size_tN/Abuflen

The size of buf, including the terminating NULL byte in case of PEM encoded data.

For CRTs in PEM encoding, the function parses permissively: if at least one certificate can be parsed, the function returns the number of certificates for which parsing failed (hence 0 if all certificates were parsed successfully). If no certificate could be parsed, the function returns the first (negative) error encountered during parsing.

PEM encoded certificates may be interleaved by other data such as human readable descriptions of their content, as long as the certificates are enclosed in the PEM specific '--—{BEGIN/END} CERTIFICATE--—' delimiters.

Note

  • If #MBEDTLS_USE_PSA_CRYPTO is enabled, the PSA crypto subsystem must have been initialized by calling psa_crypto_init() before calling this function.

Returns

  • 0 if all certificates were parsed successfully.

  • The (positive) number of certificates that couldn't be parsed if parsing was partly successful (see above).

  • A negative X509 or PEM error code otherwise.


mbedtls_x509_crt_info#

int mbedtls_x509_crt_info (char * buf, size_t size, const char * prefix, const mbedtls_x509_crt * crt)

Returns an informational string about the certificate.

Parameters
TypeDirectionArgument NameDescription
char *N/Abuf

Buffer to write to

size_tN/Asize

Maximum size of buffer

const char *N/Aprefix

A line prefix

const mbedtls_x509_crt *N/Acrt

The X509 certificate to represent

Returns

  • The length of the string written (not including the terminated nul byte), or a negative error code.


mbedtls_x509_crt_verify_info#

int mbedtls_x509_crt_verify_info (char * buf, size_t size, const char * prefix, uint32_t flags)

Returns an informational string about the verification status of a certificate.

Parameters
TypeDirectionArgument NameDescription
char *N/Abuf

Buffer to write to

size_tN/Asize

Maximum size of buffer

const char *N/Aprefix

A line prefix

uint32_tN/Aflags

Verification flags created by mbedtls_x509_crt_verify()

Returns

  • The length of the string written (not including the terminated nul byte), or a negative error code.


mbedtls_x509_crt_verify#

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(*)(void *, mbedtls_x509_crt *, int, uint32_t *) f_vrfy, void * p_vrfy)

Verify a chain of certificates.

Parameters
TypeDirectionArgument NameDescription
mbedtls_x509_crt *N/Acrt

The certificate chain to be verified.

mbedtls_x509_crt *N/Atrust_ca

The list of trusted CAs.

mbedtls_x509_crl *N/Aca_crl

The list of CRLs for trusted CAs.

const char *N/Acn

The expected Common Name. This will be checked to be present in the certificate's subjectAltNames extension or, if this extension is absent, as a CN component in its Subject name. DNS names and IP addresses are fully supported, while the URI subtype is partially supported: only exact matching, without any normalization procedures described in 7.4 of RFC5280, will result in a positive URI verification. This may be NULL if the CN need not be verified.

uint32_t *N/Aflags

The address at which to store the result of the verification. If the verification couldn't be completed, the flag value is set to (uint32_t) -1.

int(*)(void *, mbedtls_x509_crt *, int, uint32_t *)N/Af_vrfy

The verification callback to use. See the documentation of mbedtls_x509_crt_verify() for more information.

void *N/Ap_vrfy

The context to be passed to f_vrfy.

            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 mbedtls_x509_crt_verify_info()

  • Same as mbedtls_x509_crt_verify_with_profile() with the default security profile.

  • 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.

  • The 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.

Returns

  • 0 if the chain is valid with respect to the passed CN, CAs, CRLs and security profile.

  • MBEDTLS_ERR_X509_CERT_VERIFY_FAILED in case the certificate chain verification failed. In this case, *flags will have one or more MBEDTLS_X509_BADCERT_XXX or MBEDTLS_X509_BADCRL_XXX flags set.

  • Another negative error code in case of a fatal error encountered during the verification process.


mbedtls_x509_crt_verify_with_profile#

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(*)(void *, mbedtls_x509_crt *, int, uint32_t *) f_vrfy, void * p_vrfy)

Verify a chain of certificates with respect to a configurable security profile.

Parameters
TypeDirectionArgument NameDescription
mbedtls_x509_crt *N/Acrt

The certificate chain to be verified.

mbedtls_x509_crt *N/Atrust_ca

The list of trusted CAs.

mbedtls_x509_crl *N/Aca_crl

The list of CRLs for trusted CAs.

const mbedtls_x509_crt_profile *N/Aprofile

The security profile to use for the verification.

const char *N/Acn

The expected Common Name. This may be NULL if the CN need not be verified.

uint32_t *N/Aflags

The address at which to store the result of the verification. If the verification couldn't be completed, the flag value is set to (uint32_t) -1.

int(*)(void *, mbedtls_x509_crt *, int, uint32_t *)N/Af_vrfy

The verification callback to use. See the documentation of mbedtls_x509_crt_verify() for more information.

void *N/Ap_vrfy

The context to be passed to f_vrfy.

Note

  • Same as mbedtls_x509_crt_verify(), but with explicit security profile.

  • 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.

Returns

  • 0 if the chain is valid with respect to the passed CN, CAs, CRLs and security profile.

  • MBEDTLS_ERR_X509_CERT_VERIFY_FAILED in case the certificate chain verification failed. In this case, *flags will have one or more MBEDTLS_X509_BADCERT_XXX or MBEDTLS_X509_BADCRL_XXX flags set.

  • Another negative error code in case of a fatal error encountered during the verification process.


mbedtls_x509_crt_verify_restartable#

int mbedtls_x509_crt_verify_restartable (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(*)(void *, mbedtls_x509_crt *, int, uint32_t *) f_vrfy, void * p_vrfy, mbedtls_x509_crt_restart_ctx * rs_ctx)

Restartable version of mbedtls_crt_verify_with_profile()

Parameters
TypeDirectionArgument NameDescription
mbedtls_x509_crt *N/Acrt

The certificate chain to be verified.

mbedtls_x509_crt *N/Atrust_ca

The list of trusted CAs.

mbedtls_x509_crl *N/Aca_crl

The list of CRLs for trusted CAs.

const mbedtls_x509_crt_profile *N/Aprofile

The security profile to use for the verification.

const char *N/Acn

The expected Common Name. This may be NULL if the CN need not be verified.

uint32_t *N/Aflags

The address at which to store the result of the verification. If the verification couldn't be completed, the flag value is set to (uint32_t) -1.

int(*)(void *, mbedtls_x509_crt *, int, uint32_t *)N/Af_vrfy

The verification callback to use. See the documentation of mbedtls_x509_crt_verify() for more information.

void *N/Ap_vrfy

The context to be passed to f_vrfy.

mbedtls_x509_crt_restart_ctx *N/Ars_ctx

The restart context to use. This may be set to NULL to disable restartable ECC.

Note

  • Performs the same job as mbedtls_crt_verify_with_profile() but can return early and restart according to the limit set with mbedtls_ecp_set_max_ops() to reduce blocking.

Returns

  • See mbedtls_crt_verify_with_profile(), or

  • #MBEDTLS_ERR_ECP_IN_PROGRESS if maximum number of operations was reached: see mbedtls_ecp_set_max_ops().


mbedtls_x509_crt_check_key_usage#

int mbedtls_x509_crt_check_key_usage (const mbedtls_x509_crt * crt, unsigned int usage)

Check usage of certificate against keyUsage extension.

Parameters
TypeDirectionArgument NameDescription
const mbedtls_x509_crt *N/Acrt

Leaf certificate used.

unsigned intN/Ausage

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.

Returns

  • 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 mbedtls_x509_crt_verify().


mbedtls_x509_crt_check_extended_key_usage#

int mbedtls_x509_crt_check_extended_key_usage (const mbedtls_x509_crt * crt, const char * usage_oid, size_t usage_len)

Check usage of certificate against extendedKeyUsage.

Parameters
TypeDirectionArgument NameDescription
const mbedtls_x509_crt *N/Acrt

Leaf certificate used.

const char *N/Ausage_oid

Intended usage (eg MBEDTLS_OID_SERVER_AUTH or MBEDTLS_OID_CLIENT_AUTH).

size_tN/Ausage_len

Length of usage_oid (eg given by MBEDTLS_OID_SIZE()).

Returns

  • 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.


mbedtls_x509_crt_is_revoked#

int mbedtls_x509_crt_is_revoked (const mbedtls_x509_crt * crt, const mbedtls_x509_crl * crl)

Verify the certificate revocation status.

Parameters
TypeDirectionArgument NameDescription
const mbedtls_x509_crt *N/Acrt

a certificate to be verified

const mbedtls_x509_crl *N/Acrl

the CRL to verify against

Returns

  • 1 if the certificate is revoked, 0 otherwise


mbedtls_x509_crt_init#

void mbedtls_x509_crt_init (mbedtls_x509_crt * crt)

Initialize a certificate (chain)

Parameters
TypeDirectionArgument NameDescription
mbedtls_x509_crt *N/Acrt

Certificate chain to initialize


mbedtls_x509_crt_free#

void mbedtls_x509_crt_free (mbedtls_x509_crt * crt)

Unallocate all certificate data.

Parameters
TypeDirectionArgument NameDescription
mbedtls_x509_crt *N/Acrt

Certificate chain to free


mbedtls_x509_crt_has_ext_type#

static int mbedtls_x509_crt_has_ext_type (const mbedtls_x509_crt * ctx, int ext_type)

Query certificate for given extension type.

Parameters
TypeDirectionArgument NameDescription
const mbedtls_x509_crt *[in]ctx

Certificate context to be queried, must not be NULL

intN/Aext_type

Extension type being queried for, must be a valid extension type. Must be one of the MBEDTLS_X509_EXT_XXX values

Returns

  • 0 if the given extension type is not present, non-zero otherwise


Structures for parsing X.509 certificates, CRLs and CSRs Documentation#

mbedtls_x509_buf#

typedef mbedtls_asn1_buf mbedtls_x509_buf

Type-length-value structure that allows for ASN1 using DER.


mbedtls_x509_bitstring#

typedef mbedtls_asn1_bitstring mbedtls_x509_bitstring

Container for ASN1 bit strings.


mbedtls_x509_name#

typedef mbedtls_asn1_named_data mbedtls_x509_name

Container for ASN1 named information objects.

It allows for Relative Distinguished Names (e.g. cn=localhost,ou=code,etc.).


mbedtls_x509_sequence#

typedef mbedtls_asn1_sequence mbedtls_x509_sequence

Container for a sequence of ASN.1 items.


Structures and functions for parsing CRLs Documentation#

mbedtls_x509_crl_parse_der#

int mbedtls_x509_crl_parse_der (mbedtls_x509_crl * chain, const unsigned char * buf, size_t buflen)

Parse a DER-encoded CRL and append it to the chained list.

Parameters
TypeDirectionArgument NameDescription
mbedtls_x509_crl *N/Achain

points to the start of the chain

const unsigned char *N/Abuf

buffer holding the CRL data in DER format

size_tN/Abuflen

size of the buffer (including the terminating null byte for PEM data)

Note

  • If #MBEDTLS_USE_PSA_CRYPTO is enabled, the PSA crypto subsystem must have been initialized by calling psa_crypto_init() before calling this function.

Returns

  • 0 if successful, or a specific X509 or PEM error code


mbedtls_x509_crl_parse#

int mbedtls_x509_crl_parse (mbedtls_x509_crl * chain, const unsigned char * buf, size_t buflen)

Parse one or more CRLs and append them to the chained list.

Parameters
TypeDirectionArgument NameDescription
mbedtls_x509_crl *N/Achain

points to the start of the chain

const unsigned char *N/Abuf

buffer holding the CRL data in PEM or DER format

size_tN/Abuflen

size of the buffer (including the terminating null byte for PEM data)

Note

  • Multiple CRLs are accepted only if using PEM format

  • If #MBEDTLS_USE_PSA_CRYPTO is enabled, the PSA crypto subsystem must have been initialized by calling psa_crypto_init() before calling this function.

Returns

  • 0 if successful, or a specific X509 or PEM error code


mbedtls_x509_crl_info#

int mbedtls_x509_crl_info (char * buf, size_t size, const char * prefix, const mbedtls_x509_crl * crl)

Returns an informational string about the CRL.

Parameters
TypeDirectionArgument NameDescription
char *N/Abuf

Buffer to write to

size_tN/Asize

Maximum size of buffer

const char *N/Aprefix

A line prefix

const mbedtls_x509_crl *N/Acrl

The X509 CRL to represent

Returns

  • The length of the string written (not including the terminated nul byte), or a negative error code.


mbedtls_x509_crl_init#

void mbedtls_x509_crl_init (mbedtls_x509_crl * crl)

Initialize a CRL (chain)

Parameters
TypeDirectionArgument NameDescription
mbedtls_x509_crl *N/Acrl

CRL chain to initialize


mbedtls_x509_crl_free#

void mbedtls_x509_crl_free (mbedtls_x509_crl * crl)

Unallocate all CRL data.

Parameters
TypeDirectionArgument NameDescription
mbedtls_x509_crl *N/Acrl

CRL chain to free


Structures and functions for X.509 Certificate Signing Requests (CSR) Documentation#

mbedtls_x509_csr_parse_der#

int mbedtls_x509_csr_parse_der (mbedtls_x509_csr * csr, const unsigned char * buf, size_t buflen)

Load a Certificate Signing Request (CSR) in DER format.

Parameters
TypeDirectionArgument NameDescription
mbedtls_x509_csr *N/Acsr

CSR context to fill

const unsigned char *N/Abuf

buffer holding the CRL data

size_tN/Abuflen

size of the buffer

Note

  • CSR attributes (if any) are currently silently ignored.

  • If #MBEDTLS_USE_PSA_CRYPTO is enabled, the PSA crypto subsystem must have been initialized by calling psa_crypto_init() before calling this function.

Returns

  • 0 if successful, or a specific X509 error code


mbedtls_x509_csr_parse#

int mbedtls_x509_csr_parse (mbedtls_x509_csr * csr, const unsigned char * buf, size_t buflen)

Load a Certificate Signing Request (CSR), DER or PEM format.

Parameters
TypeDirectionArgument NameDescription
mbedtls_x509_csr *N/Acsr

CSR context to fill

const unsigned char *N/Abuf

buffer holding the CRL data

size_tN/Abuflen

size of the buffer (including the terminating null byte for PEM data)

Note

  • See notes for mbedtls_x509_csr_parse_der()

  • If #MBEDTLS_USE_PSA_CRYPTO is enabled, the PSA crypto subsystem must have been initialized by calling psa_crypto_init() before calling this function.

Returns

  • 0 if successful, or a specific X509 or PEM error code


mbedtls_x509_csr_info#

int mbedtls_x509_csr_info (char * buf, size_t size, const char * prefix, const mbedtls_x509_csr * csr)

Returns an informational string about the CSR.

Parameters
TypeDirectionArgument NameDescription
char *N/Abuf

Buffer to write to

size_tN/Asize

Maximum size of buffer

const char *N/Aprefix

A line prefix

const mbedtls_x509_csr *N/Acsr

The X509 CSR to represent

Returns

  • The length of the string written (not including the terminated nul byte), or a negative error code.


mbedtls_x509_csr_init#

void mbedtls_x509_csr_init (mbedtls_x509_csr * csr)

Initialize a CSR.

Parameters
TypeDirectionArgument NameDescription
mbedtls_x509_csr *N/Acsr

CSR to initialize


mbedtls_x509_csr_free#

void mbedtls_x509_csr_free (mbedtls_x509_csr * csr)

Unallocate all CSR data.

Parameters
TypeDirectionArgument NameDescription
mbedtls_x509_csr *N/Acsr

CSR to free


X509 Error codes Documentation#

X509 Verify codes Documentation#

Function Documentation#

mbedtls_x509write_crt_init#

void mbedtls_x509write_crt_init (mbedtls_x509write_cert * ctx)

Initialize a CRT writing context.

Parameters
TypeDirectionArgument NameDescription
mbedtls_x509write_cert *N/Actx

CRT context to initialize


mbedtls_x509write_crt_set_version#

void mbedtls_x509write_crt_set_version (mbedtls_x509write_cert * ctx, int version)

Set the version for a Certificate Default: MBEDTLS_X509_CRT_VERSION_3.

Parameters
TypeDirectionArgument NameDescription
mbedtls_x509write_cert *N/Actx

CRT context to use

intN/Aversion

version to set (MBEDTLS_X509_CRT_VERSION_1, MBEDTLS_X509_CRT_VERSION_2 or MBEDTLS_X509_CRT_VERSION_3)


mbedtls_x509write_crt_set_serial#

int MBEDTLS_DEPRECATED mbedtls_x509write_crt_set_serial (mbedtls_x509write_cert * ctx, const mbedtls_mpi * serial)

Set the serial number for a Certificate.

Parameters
TypeDirectionArgument NameDescription
mbedtls_x509write_cert *N/Actx

CRT context to use

const mbedtls_mpi *N/Aserial

serial number to set

Note

  • Even though the MBEDTLS_BIGNUM_C guard looks redundant since X509 depends on PK and PK depends on BIGNUM, this emphasizes a direct dependency between X509 and BIGNUM which is going to be deprecated in the future.

Returns

  • 0 if successful


mbedtls_x509write_crt_set_serial_raw#

int mbedtls_x509write_crt_set_serial_raw (mbedtls_x509write_cert * ctx, unsigned char * serial, size_t serial_len)

Set the serial number for a Certificate.

Parameters
TypeDirectionArgument NameDescription
mbedtls_x509write_cert *N/Actx

CRT context to use

unsigned char *N/Aserial

A raw array of bytes containing the serial number in big endian format

size_tN/Aserial_len

Length of valid bytes (expressed in bytes) in serial input buffer

Returns

  • 0 if successful, or MBEDTLS_ERR_X509_BAD_INPUT_DATA if the provided input buffer is too big (longer than MBEDTLS_X509_RFC5280_MAX_SERIAL_LEN)


mbedtls_x509write_crt_set_validity#

int mbedtls_x509write_crt_set_validity (mbedtls_x509write_cert * ctx, const char * not_before, const char * not_after)

Set the validity period for a Certificate Timestamps should be in string format for UTC timezone i.e.

Parameters
TypeDirectionArgument NameDescription
mbedtls_x509write_cert *N/Actx

CRT context to use

const char *N/Anot_before

not_before timestamp

const char *N/Anot_after

not_after timestamp

"YYYYMMDDhhmmss" e.g. "20131231235959" for December 31st 2013 at 23:59:59

Returns

  • 0 if timestamp was parsed successfully, or a specific error code


mbedtls_x509write_crt_set_issuer_name#

int mbedtls_x509write_crt_set_issuer_name (mbedtls_x509write_cert * ctx, const char * issuer_name)

Set the issuer name for a Certificate Issuer names should contain a comma-separated list of OID types and values: e.g.

Parameters
TypeDirectionArgument NameDescription
mbedtls_x509write_cert *N/Actx

CRT context to use

const char *N/Aissuer_name

issuer name to set

"C=UK,O=ARM,CN=Mbed TLS CA"

Returns

  • 0 if issuer name was parsed successfully, or a specific error code


mbedtls_x509write_crt_set_subject_name#

int mbedtls_x509write_crt_set_subject_name (mbedtls_x509write_cert * ctx, const char * subject_name)

Set the subject name for a Certificate Subject names should contain a comma-separated list of OID types and values: e.g.

Parameters
TypeDirectionArgument NameDescription
mbedtls_x509write_cert *N/Actx

CRT context to use

const char *N/Asubject_name

subject name to set

"C=UK,O=ARM,CN=Mbed TLS Server 1"

Returns

  • 0 if subject name was parsed successfully, or a specific error code


mbedtls_x509write_crt_set_subject_key#

void mbedtls_x509write_crt_set_subject_key (mbedtls_x509write_cert * ctx, mbedtls_pk_context * key)

Set the subject public key for the certificate.

Parameters
TypeDirectionArgument NameDescription
mbedtls_x509write_cert *N/Actx

CRT context to use

mbedtls_pk_context *N/Akey

public key to include


mbedtls_x509write_crt_set_issuer_key#

void mbedtls_x509write_crt_set_issuer_key (mbedtls_x509write_cert * ctx, mbedtls_pk_context * key)

Set the issuer key used for signing the certificate.

Parameters
TypeDirectionArgument NameDescription
mbedtls_x509write_cert *N/Actx

CRT context to use

mbedtls_pk_context *N/Akey

private key to sign with


mbedtls_x509write_crt_set_md_alg#

void mbedtls_x509write_crt_set_md_alg (mbedtls_x509write_cert * ctx, mbedtls_md_type_t md_alg)

Set the MD algorithm to use for the signature (e.g.

Parameters
TypeDirectionArgument NameDescription
mbedtls_x509write_cert *N/Actx

CRT context to use

mbedtls_md_type_tN/Amd_alg

MD algorithm to use

MBEDTLS_MD_SHA1)


mbedtls_x509write_crt_set_extension#

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)

Generic function to add to or replace an extension in the CRT.

Parameters
TypeDirectionArgument NameDescription
mbedtls_x509write_cert *N/Actx

CRT context to use

const char *N/Aoid

OID of the extension

size_tN/Aoid_len

length of the OID

intN/Acritical

if the extension is critical (per the RFC's definition)

const unsigned char *N/Aval

value of the extension OCTET STRING

size_tN/Aval_len

length of the value data

Returns

  • 0 if successful, or a MBEDTLS_ERR_X509_ALLOC_FAILED


mbedtls_x509write_crt_set_basic_constraints#

int mbedtls_x509write_crt_set_basic_constraints (mbedtls_x509write_cert * ctx, int is_ca, int max_pathlen)

Set the basicConstraints extension for a CRT.

Parameters
TypeDirectionArgument NameDescription
mbedtls_x509write_cert *N/Actx

CRT context to use

intN/Ais_ca

is this a CA certificate

intN/Amax_pathlen

maximum length of certificate chains below this certificate (only for CA certificates, -1 is unlimited)

Returns

  • 0 if successful, or a MBEDTLS_ERR_X509_ALLOC_FAILED


mbedtls_x509write_crt_set_key_usage#

int mbedtls_x509write_crt_set_key_usage (mbedtls_x509write_cert * ctx, unsigned int key_usage)

Set the Key Usage Extension flags (e.g.

Parameters
TypeDirectionArgument NameDescription
mbedtls_x509write_cert *N/Actx

CRT context to use

unsigned intN/Akey_usage

key usage flags to set

MBEDTLS_X509_KU_DIGITAL_SIGNATURE | MBEDTLS_X509_KU_KEY_CERT_SIGN)

Returns

  • 0 if successful, or MBEDTLS_ERR_X509_ALLOC_FAILED


mbedtls_x509write_crt_set_ext_key_usage#

int mbedtls_x509write_crt_set_ext_key_usage (mbedtls_x509write_cert * ctx, const mbedtls_asn1_sequence * exts)

Set the Extended Key Usage Extension (e.g.

Parameters
TypeDirectionArgument NameDescription
mbedtls_x509write_cert *N/Actx

CRT context to use

const mbedtls_asn1_sequence *N/Aexts

extended key usage extensions to set, a sequence of MBEDTLS_ASN1_OID objects

MBEDTLS_OID_SERVER_AUTH)

Returns

  • 0 if successful, or MBEDTLS_ERR_X509_ALLOC_FAILED


mbedtls_x509write_crt_set_ns_cert_type#

int mbedtls_x509write_crt_set_ns_cert_type (mbedtls_x509write_cert * ctx, unsigned char ns_cert_type)

Set the Netscape Cert Type flags (e.g.

Parameters
TypeDirectionArgument NameDescription
mbedtls_x509write_cert *N/Actx

CRT context to use

unsigned charN/Ans_cert_type

Netscape Cert Type flags to set

MBEDTLS_X509_NS_CERT_TYPE_SSL_CLIENT | MBEDTLS_X509_NS_CERT_TYPE_EMAIL)

Returns

  • 0 if successful, or MBEDTLS_ERR_X509_ALLOC_FAILED


mbedtls_x509write_crt_free#

void mbedtls_x509write_crt_free (mbedtls_x509write_cert * ctx)

Free the contents of a CRT write context.

Parameters
TypeDirectionArgument NameDescription
mbedtls_x509write_cert *N/Actx

CRT context to free


mbedtls_x509write_crt_der#

int mbedtls_x509write_crt_der (mbedtls_x509write_cert * ctx, unsigned char * buf, size_t size, int(*)(void *, unsigned char *, size_t) f_rng, void * p_rng)

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.

Parameters
TypeDirectionArgument NameDescription
mbedtls_x509write_cert *N/Actx

certificate to write away

unsigned char *N/Abuf

buffer to write to

size_tN/Asize

size of the buffer

int(*)(void *, unsigned char *, size_t)N/Af_rng

RNG function. This must not be NULL.

void *N/Ap_rng

RNG parameter

Returns

  • length of data written if successful, or a specific error code

Note

  • f_rng is used for the signature operation.


mbedtls_x509write_crt_pem#

int mbedtls_x509write_crt_pem (mbedtls_x509write_cert * ctx, unsigned char * buf, size_t size, int(*)(void *, unsigned char *, size_t) f_rng, void * p_rng)

Write a built up certificate to a X509 PEM string.

Parameters
TypeDirectionArgument NameDescription
mbedtls_x509write_cert *N/Actx

certificate to write away

unsigned char *N/Abuf

buffer to write to

size_tN/Asize

size of the buffer

int(*)(void *, unsigned char *, size_t)N/Af_rng

RNG function. This must not be NULL.

void *N/Ap_rng

RNG parameter

Returns

  • 0 if successful, or a specific error code

Note

  • f_rng is used for the signature operation.


mbedtls_x509write_csr_init#

void mbedtls_x509write_csr_init (mbedtls_x509write_csr * ctx)

Initialize a CSR context.

Parameters
TypeDirectionArgument NameDescription
mbedtls_x509write_csr *N/Actx

CSR context to initialize


mbedtls_x509write_csr_set_subject_name#

int mbedtls_x509write_csr_set_subject_name (mbedtls_x509write_csr * ctx, const char * subject_name)

Set the subject name for a CSR Subject names should contain a comma-separated list of OID types and values: e.g.

Parameters
TypeDirectionArgument NameDescription
mbedtls_x509write_csr *N/Actx

CSR context to use

const char *N/Asubject_name

subject name to set

"C=UK,O=ARM,CN=Mbed TLS Server 1"

Returns

  • 0 if subject name was parsed successfully, or a specific error code


mbedtls_x509write_csr_set_key#

void mbedtls_x509write_csr_set_key (mbedtls_x509write_csr * ctx, mbedtls_pk_context * key)

Set the key for a CSR (public key will be included, private key used to sign the CSR when writing it)

Parameters
TypeDirectionArgument NameDescription
mbedtls_x509write_csr *N/Actx

CSR context to use

mbedtls_pk_context *N/Akey

Asymmetric key to include


mbedtls_x509write_csr_set_md_alg#

void mbedtls_x509write_csr_set_md_alg (mbedtls_x509write_csr * ctx, mbedtls_md_type_t md_alg)

Set the MD algorithm to use for the signature (e.g.

Parameters
TypeDirectionArgument NameDescription
mbedtls_x509write_csr *N/Actx

CSR context to use

mbedtls_md_type_tN/Amd_alg

MD algorithm to use

MBEDTLS_MD_SHA1)


mbedtls_x509write_csr_set_key_usage#

int mbedtls_x509write_csr_set_key_usage (mbedtls_x509write_csr * ctx, unsigned char key_usage)

Set the Key Usage Extension flags (e.g.

Parameters
TypeDirectionArgument NameDescription
mbedtls_x509write_csr *N/Actx

CSR context to use

unsigned charN/Akey_usage

key usage flags to set

MBEDTLS_X509_KU_DIGITAL_SIGNATURE | MBEDTLS_X509_KU_KEY_CERT_SIGN)

Returns

  • 0 if successful, or MBEDTLS_ERR_X509_ALLOC_FAILED

Note

  • The decipherOnly flag from the Key Usage extension is represented by bit 8 (i.e. 0x8000), which cannot typically be represented in an unsigned char. Therefore, the flag decipherOnly (i.e. #MBEDTLS_X509_KU_DECIPHER_ONLY) cannot be set using this function.


mbedtls_x509write_csr_set_subject_alternative_name#

int mbedtls_x509write_csr_set_subject_alternative_name (mbedtls_x509write_csr * ctx, const mbedtls_x509_san_list * san_list)

Set Subject Alternative Name.

Parameters
TypeDirectionArgument NameDescription
mbedtls_x509write_csr *N/Actx

CSR context to use

const mbedtls_x509_san_list *N/Asan_list

List of SAN values

Returns

  • 0 if successful, or MBEDTLS_ERR_X509_ALLOC_FAILED

Note

  • Only "dnsName", "uniformResourceIdentifier" and "otherName", as defined in RFC 5280, are supported.


mbedtls_x509write_csr_set_ns_cert_type#

int mbedtls_x509write_csr_set_ns_cert_type (mbedtls_x509write_csr * ctx, unsigned char ns_cert_type)

Set the Netscape Cert Type flags (e.g.

Parameters
TypeDirectionArgument NameDescription
mbedtls_x509write_csr *N/Actx

CSR context to use

unsigned charN/Ans_cert_type

Netscape Cert Type flags to set

MBEDTLS_X509_NS_CERT_TYPE_SSL_CLIENT | MBEDTLS_X509_NS_CERT_TYPE_EMAIL)

Returns

  • 0 if successful, or MBEDTLS_ERR_X509_ALLOC_FAILED


mbedtls_x509write_csr_set_extension#

int mbedtls_x509write_csr_set_extension (mbedtls_x509write_csr * ctx, const char * oid, size_t oid_len, int critical, const unsigned char * val, size_t val_len)

Generic function to add to or replace an extension in the CSR.

Parameters
TypeDirectionArgument NameDescription
mbedtls_x509write_csr *N/Actx

CSR context to use

const char *N/Aoid

OID of the extension

size_tN/Aoid_len

length of the OID

intN/Acritical

Set to 1 to mark the extension as critical, 0 otherwise.

const unsigned char *N/Aval

value of the extension OCTET STRING

size_tN/Aval_len

length of the value data

Returns

  • 0 if successful, or a MBEDTLS_ERR_X509_ALLOC_FAILED


mbedtls_x509write_csr_free#

void mbedtls_x509write_csr_free (mbedtls_x509write_csr * ctx)

Free the contents of a CSR context.

Parameters
TypeDirectionArgument NameDescription
mbedtls_x509write_csr *N/Actx

CSR context to free


mbedtls_x509write_csr_der#

int mbedtls_x509write_csr_der (mbedtls_x509write_csr * ctx, unsigned char * buf, size_t size, int(*)(void *, unsigned char *, size_t) f_rng, void * p_rng)

Write a CSR (Certificate Signing Request) to a 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.

Parameters
TypeDirectionArgument NameDescription
mbedtls_x509write_csr *N/Actx

CSR to write away

unsigned char *N/Abuf

buffer to write to

size_tN/Asize

size of the buffer

int(*)(void *, unsigned char *, size_t)N/Af_rng

RNG function. This must not be NULL.

void *N/Ap_rng

RNG parameter

Returns

  • length of data written if successful, or a specific error code

Note

  • f_rng is used for the signature operation.


mbedtls_x509write_csr_pem#

int mbedtls_x509write_csr_pem (mbedtls_x509write_csr * ctx, unsigned char * buf, size_t size, int(*)(void *, unsigned char *, size_t) f_rng, void * p_rng)

Write a CSR (Certificate Signing Request) to a PEM string.

Parameters
TypeDirectionArgument NameDescription
mbedtls_x509write_csr *N/Actx

CSR to write away

unsigned char *N/Abuf

buffer to write to

size_tN/Asize

size of the buffer

int(*)(void *, unsigned char *, size_t)N/Af_rng

RNG function. This must not be NULL.

void *N/Ap_rng

RNG parameter

Returns

  • 0 if successful, or a specific error code

Note

  • f_rng is used for the signature operation.


mbedtls_x509_dn_gets#

int mbedtls_x509_dn_gets (char * buf, size_t size, const mbedtls_x509_name * dn)

Store the certificate DN in printable form into buf; no more than size characters will be written.

Parameters
TypeDirectionArgument NameDescription
char *N/Abuf

Buffer to write to

size_tN/Asize

Maximum size of buffer

const mbedtls_x509_name *N/Adn

The X509 name to represent

Returns

  • The length of the string written (not including the terminated nul byte), or a negative error code.


mbedtls_x509_dn_get_next#

static mbedtls_x509_name * mbedtls_x509_dn_get_next (mbedtls_x509_name * dn)

Return the next relative DN in an X509 name.

Parameters
TypeDirectionArgument NameDescription
mbedtls_x509_name *N/Adn

Current node in the X509 name

Note

  • Intended use is to compare function result to dn->next in order to detect boundaries of multi-valued RDNs.

Returns

  • Pointer to the first attribute-value pair of the next RDN in sequence, or NULL if end is reached.


mbedtls_x509_serial_gets#

int mbedtls_x509_serial_gets (char * buf, size_t size, const mbedtls_x509_buf * serial)

Store the certificate serial in printable form into buf; no more than size characters will be written.

Parameters
TypeDirectionArgument NameDescription
char *N/Abuf

Buffer to write to

size_tN/Asize

Maximum size of buffer

const mbedtls_x509_buf *N/Aserial

The X509 serial to represent

Returns

  • The length of the string written (not including the terminated nul byte), or a negative error code.


mbedtls_x509_time_cmp#

int mbedtls_x509_time_cmp (const mbedtls_x509_time * t1, const mbedtls_x509_time * t2)

Compare pair of mbedtls_x509_time.

Parameters
TypeDirectionArgument NameDescription
const mbedtls_x509_time *N/At1

mbedtls_x509_time to compare

const mbedtls_x509_time *N/At2

mbedtls_x509_time to compare

Returns

  • < 0 if t1 is before t2 0 if t1 equals t2 > 0 if t1 is after t2


mbedtls_x509_time_is_past#

int mbedtls_x509_time_is_past (const mbedtls_x509_time * to)

Check a given mbedtls_x509_time against the system time and tell if it's in the past.

Parameters
TypeDirectionArgument NameDescription
const mbedtls_x509_time *N/Ato

mbedtls_x509_time to check

Note

  • Intended usage is "if( is_past( valid_to ) ) ERROR". Hence the return value of 1 if on internal errors.

Returns

  • 1 if the given time is in the past or an error occurred, 0 otherwise.


mbedtls_x509_time_is_future#

int mbedtls_x509_time_is_future (const mbedtls_x509_time * from)

Check a given mbedtls_x509_time against the system time and tell if it's in the future.

Parameters
TypeDirectionArgument NameDescription
const mbedtls_x509_time *N/Afrom

mbedtls_x509_time to check

Note

  • Intended usage is "if( is_future( valid_from ) ) ERROR". Hence the return value of 1 if on internal errors.

Returns

  • 1 if the given time is in the future or an error occurred, 0 otherwise.


mbedtls_x509_parse_subject_alt_name#

int mbedtls_x509_parse_subject_alt_name (const mbedtls_x509_buf * san_buf, mbedtls_x509_subject_alternative_name * san)

This function parses an item in the SubjectAlternativeNames extension.

Parameters
TypeDirectionArgument NameDescription
const mbedtls_x509_buf *N/Asan_buf

The buffer holding the raw data item of the subject alternative name.

mbedtls_x509_subject_alternative_name *N/Asan

The target structure to populate with the parsed presentation of the subject alternative name encoded in san_buf.

Please note that this function might allocate additional memory for a subject alternative name, thus mbedtls_x509_free_subject_alt_name has to be called to dispose of this additional memory afterwards.

Note

  • Supported GeneralName types, as defined in RFC 5280: "rfc822Name", "dnsName", "directoryName", "uniformResourceIdentifier" and "hardware_module_name" of type "otherName", as defined in RFC 4108.

  • This function should be called on a single raw data of subject alternative name. For example, after successful certificate parsing, one must iterate on every item in the crt->subject_alt_names sequence, and pass it to this function.

Warnings

  • The target structure contains pointers to the raw data of the parsed certificate, and its lifetime is restricted by the lifetime of the certificate.

Returns


mbedtls_x509_free_subject_alt_name#

void mbedtls_x509_free_subject_alt_name (mbedtls_x509_subject_alternative_name * san)

Unallocate all data related to subject alternative name.

Parameters
TypeDirectionArgument NameDescription
mbedtls_x509_subject_alternative_name *N/Asan

SAN structure - extra memory owned by this structure will be freed