Overview

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.

Data Structures
struct	mbedtls_x509_time

struct	mbedtls_x509_crl_entry

struct	mbedtls_x509_crl

struct	mbedtls_x509_crt

struct	mbedtls_x509_crt_profile

struct	mbedtls_x509write_cert

struct	mbedtls_x509_crt_verify_chain_item

struct	mbedtls_x509_crt_verify_chain

struct	mbedtls_x509_csr

struct	mbedtls_x509write_csr

Macros
#define	MBEDTLS_X509_MAX_INTERMEDIATE_CA 8

Functions
int	mbedtls_dhm_parse_dhm (mbedtls_dhm_context dhm, const unsigned char dhmin, size_t dhminlen)
	This function parses DHM parameters in PEM or DER format. More...

int	mbedtls_dhm_parse_dhmfile (mbedtls_dhm_context dhm, const char path)
	This function loads and parses DHM parameters from a file. More...

X509 Error codes
#define	MBEDTLS_ERR_X509_FEATURE_UNAVAILABLE -0x2080

#define	MBEDTLS_ERR_X509_UNKNOWN_OID -0x2100

#define	MBEDTLS_ERR_X509_INVALID_FORMAT -0x2180

#define	MBEDTLS_ERR_X509_INVALID_VERSION -0x2200

#define	MBEDTLS_ERR_X509_INVALID_SERIAL -0x2280

#define	MBEDTLS_ERR_X509_INVALID_ALG -0x2300

#define	MBEDTLS_ERR_X509_INVALID_NAME -0x2380

#define	MBEDTLS_ERR_X509_INVALID_DATE -0x2400

#define	MBEDTLS_ERR_X509_INVALID_SIGNATURE -0x2480

#define	MBEDTLS_ERR_X509_INVALID_EXTENSIONS -0x2500

#define	MBEDTLS_ERR_X509_UNKNOWN_VERSION -0x2580

#define	MBEDTLS_ERR_X509_UNKNOWN_SIG_ALG -0x2600

#define	MBEDTLS_ERR_X509_SIG_MISMATCH -0x2680

#define	MBEDTLS_ERR_X509_CERT_VERIFY_FAILED -0x2700

#define	MBEDTLS_ERR_X509_CERT_UNKNOWN_FORMAT -0x2780

#define	MBEDTLS_ERR_X509_BAD_INPUT_DATA -0x2800

#define	MBEDTLS_ERR_X509_ALLOC_FAILED -0x2880

#define	MBEDTLS_ERR_X509_FILE_IO_ERROR -0x2900

#define	MBEDTLS_ERR_X509_BUFFER_TOO_SMALL -0x2980

#define	MBEDTLS_ERR_X509_FATAL_ERROR -0x3000

X509 Verify codes
#define	MBEDTLS_X509_BADCERT_EXPIRED 0x01

#define	MBEDTLS_X509_BADCERT_REVOKED 0x02

#define	MBEDTLS_X509_BADCERT_CN_MISMATCH 0x04

#define	MBEDTLS_X509_BADCERT_NOT_TRUSTED 0x08

#define	MBEDTLS_X509_BADCRL_NOT_TRUSTED 0x10

#define	MBEDTLS_X509_BADCRL_EXPIRED 0x20

#define	MBEDTLS_X509_BADCERT_MISSING 0x40

#define	MBEDTLS_X509_BADCERT_SKIP_VERIFY 0x80

#define	MBEDTLS_X509_BADCERT_OTHER 0x0100

#define	MBEDTLS_X509_BADCERT_FUTURE 0x0200

#define	MBEDTLS_X509_BADCRL_FUTURE 0x0400

#define	MBEDTLS_X509_BADCERT_KEY_USAGE 0x0800

#define	MBEDTLS_X509_BADCERT_EXT_KEY_USAGE 0x1000

#define	MBEDTLS_X509_BADCERT_NS_CERT_TYPE 0x2000

#define	MBEDTLS_X509_BADCERT_BAD_MD 0x4000

#define	MBEDTLS_X509_BADCERT_BAD_PK 0x8000

#define	MBEDTLS_X509_BADCERT_BAD_KEY 0x010000

#define	MBEDTLS_X509_BADCRL_BAD_MD 0x020000

#define	MBEDTLS_X509_BADCRL_BAD_PK 0x040000

#define	MBEDTLS_X509_BADCRL_BAD_KEY 0x080000

Structures for parsing X.509 certificates, CRLs and CSRs
typedef mbedtls_asn1_buf	mbedtls_x509_buf

typedef mbedtls_asn1_bitstring	mbedtls_x509_bitstring

typedef mbedtls_asn1_named_data	mbedtls_x509_name

typedef mbedtls_asn1_sequence	mbedtls_x509_sequence

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. More...

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. More...

int	mbedtls_x509_crl_parse_file (mbedtls_x509_crl chain, const char path)
	Load one or more CRLs and append them to the chained list. More...

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. More...

void	mbedtls_x509_crl_init (mbedtls_x509_crl *crl)
	Initialize a CRL (chain) More...

void	mbedtls_x509_crl_free (mbedtls_x509_crl *crl)
	Unallocate all CRL data. More...

Structures and functions for parsing and writing X.509 certificates
typedef void	mbedtls_x509_crt_restart_ctx

const mbedtls_x509_crt_profile	mbedtls_x509_crt_profile_default

const mbedtls_x509_crt_profile	mbedtls_x509_crt_profile_next

const mbedtls_x509_crt_profile	mbedtls_x509_crt_profile_suiteb

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 chained list. More...

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. More...

int	mbedtls_x509_crt_parse_file (mbedtls_x509_crt chain, const char path)
	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. More...

int	mbedtls_x509_crt_parse_path (mbedtls_x509_crt chain, const char path)
	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. More...

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. More...

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. More...

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 the certificate signature. More...

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 the certificate signature according to profile. More...

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()` More...

int	mbedtls_x509_crt_check_key_usage (const mbedtls_x509_crt *crt, unsigned int usage)
	Check usage of certificate against keyUsage extension. More...

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. More...

int	mbedtls_x509_crt_is_revoked (const mbedtls_x509_crt crt, const mbedtls_x509_crl crl)
	Verify the certificate revocation status. More...

void	mbedtls_x509_crt_init (mbedtls_x509_crt *crt)
	Initialize a certificate (chain) More...

void	mbedtls_x509_crt_free (mbedtls_x509_crt *crt)
	Unallocate all certificate data. More...

#define	MBEDTLS_X509_ID_FLAG(id) ( 1 << ( (id) - 1 ) )

#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

#define	MBEDTLS_X509_MAX_FILE_PATH_LEN 512

#define	MBEDTLS_X509_MAX_VERIFY_CHAIN_SIZE ( MBEDTLS_X509_MAX_INTERMEDIATE_CA + 2 )

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. More...

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. More...

int	mbedtls_x509_csr_parse_file (mbedtls_x509_csr csr, const char path)
	Load a Certificate Signing Request (CSR) More...

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. More...

void	mbedtls_x509_csr_init (mbedtls_x509_csr *csr)
	Initialize a CSR. More...

void	mbedtls_x509_csr_free (mbedtls_x509_csr *csr)
	Unallocate all CSR data. More...

Data Structure Documentation

struct mbedtls_x509_time

Container for date and time (precision in seconds).

Data Fields
int	day

int	sec

Field Documentation

int mbedtls_x509_time::day

Date.

int mbedtls_x509_time::sec

Time.

struct mbedtls_x509_crl_entry

Certificate revocation list entry. Contains the CA-specific serial numbers and revocation dates.

struct mbedtls_x509_crl

Certificate revocation list structure. Every CRL may have multiple entries.

Data Fields
mbedtls_x509_buf	raw

mbedtls_x509_buf	tbs

int	version

mbedtls_x509_buf	sig_oid

mbedtls_x509_buf	issuer_raw

mbedtls_x509_name	issuer

mbedtls_x509_crl_entry	entry

mbedtls_md_type_t	sig_md

mbedtls_pk_type_t	sig_pk

void *	sig_opts

Field Documentation

mbedtls_x509_buf mbedtls_x509_crl::raw

The raw certificate data (DER).

mbedtls_x509_buf mbedtls_x509_crl::tbs

The raw certificate body (DER). The part that is To Be Signed.

int mbedtls_x509_crl::version

CRL version (1=v1, 2=v2)

mbedtls_x509_buf mbedtls_x509_crl::sig_oid

CRL signature type identifier

mbedtls_x509_buf mbedtls_x509_crl::issuer_raw

The raw issuer data (DER).

mbedtls_x509_name mbedtls_x509_crl::issuer

The parsed issuer data (named information object).

mbedtls_x509_crl_entry mbedtls_x509_crl::entry

The CRL entries containing the certificate revocation times for this CA.

mbedtls_md_type_t mbedtls_x509_crl::sig_md

Internal representation of the MD algorithm of the signature algorithm, e.g. MBEDTLS_MD_SHA256

mbedtls_pk_type_t mbedtls_x509_crl::sig_pk

Internal representation of the Public Key algorithm of the signature algorithm, e.g. MBEDTLS_PK_RSA

void* mbedtls_x509_crl::sig_opts

Signature options to be passed to mbedtls_pk_verify_ext(), e.g. for RSASSA-PSS

struct mbedtls_x509_crt

Container for an X.509 certificate. The certificate may be chained.

Data Fields
mbedtls_x509_buf	raw

mbedtls_x509_buf	tbs

int	version

mbedtls_x509_buf	serial

mbedtls_x509_buf	sig_oid

mbedtls_x509_buf	issuer_raw

mbedtls_x509_buf	subject_raw

mbedtls_x509_name	issuer

mbedtls_x509_name	subject

mbedtls_x509_time	valid_from

mbedtls_x509_time	valid_to

mbedtls_pk_context	pk

mbedtls_x509_buf	issuer_id

mbedtls_x509_buf	subject_id

mbedtls_x509_buf	v3_ext

mbedtls_x509_sequence	subject_alt_names

int	ext_types

int	ca_istrue

int	max_pathlen

unsigned int	key_usage

mbedtls_x509_sequence	ext_key_usage

unsigned char	ns_cert_type

mbedtls_x509_buf	sig

mbedtls_md_type_t	sig_md

mbedtls_pk_type_t	sig_pk

void *	sig_opts

struct mbedtls_x509_crt *	next

Field Documentation

mbedtls_x509_buf mbedtls_x509_crt::raw

The raw certificate data (DER).

mbedtls_x509_buf mbedtls_x509_crt::tbs

The raw certificate body (DER). The part that is To Be Signed.

int mbedtls_x509_crt::version

The X.509 version. (1=v1, 2=v2, 3=v3)

mbedtls_x509_buf mbedtls_x509_crt::serial

Unique id for certificate issued by a specific CA.

mbedtls_x509_buf mbedtls_x509_crt::sig_oid

Signature algorithm, e.g. sha1RSA

mbedtls_x509_buf mbedtls_x509_crt::issuer_raw

The raw issuer data (DER). Used for quick comparison.

mbedtls_x509_buf mbedtls_x509_crt::subject_raw

The raw subject data (DER). Used for quick comparison.

mbedtls_x509_name mbedtls_x509_crt::issuer

The parsed issuer data (named information object).

mbedtls_x509_name mbedtls_x509_crt::subject

The parsed subject data (named information object).

mbedtls_x509_time mbedtls_x509_crt::valid_from

Start time of certificate validity.

mbedtls_x509_time mbedtls_x509_crt::valid_to

End time of certificate validity.

mbedtls_pk_context mbedtls_x509_crt::pk

Container for the public key context.

mbedtls_x509_buf mbedtls_x509_crt::issuer_id

Optional X.509 v2/v3 issuer unique identifier.

mbedtls_x509_buf mbedtls_x509_crt::subject_id

Optional X.509 v2/v3 subject unique identifier.

mbedtls_x509_buf mbedtls_x509_crt::v3_ext

Optional X.509 v3 extensions.

mbedtls_x509_sequence mbedtls_x509_crt::subject_alt_names

Optional list of Subject Alternative Names (Only dNSName supported).

int mbedtls_x509_crt::ext_types

Bit string containing detected and parsed extensions

int mbedtls_x509_crt::ca_istrue

Optional Basic Constraint extension value: 1 if this certificate belongs to a CA, 0 otherwise.

int mbedtls_x509_crt::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 mbedtls_x509_crt::key_usage

Optional key usage extension value: See the values in x509.h

mbedtls_x509_sequence mbedtls_x509_crt::ext_key_usage

Optional list of extended key usage OIDs.

unsigned char mbedtls_x509_crt::ns_cert_type

Optional Netscape certificate type extension value: See the values in x509.h

mbedtls_x509_buf mbedtls_x509_crt::sig

Signature: hash of the tbs part signed with the private key.

mbedtls_md_type_t mbedtls_x509_crt::sig_md

Internal representation of the MD algorithm of the signature algorithm, e.g. MBEDTLS_MD_SHA256

mbedtls_pk_type_t mbedtls_x509_crt::sig_pk

Internal representation of the Public Key algorithm of the signature algorithm, e.g. MBEDTLS_PK_RSA

void* mbedtls_x509_crt::sig_opts

Signature options to be passed to mbedtls_pk_verify_ext(), e.g. for RSASSA-PSS

struct mbedtls_x509_crt* mbedtls_x509_crt::next

Next certificate in the CA-chain.

struct mbedtls_x509_crt_profile

Security profile for certificate verification.

All lists are bitfields, built by ORing flags from MBEDTLS_X509_ID_FLAG().

Data Fields
uint32_t	allowed_mds

uint32_t	allowed_pks

uint32_t	allowed_curves

uint32_t	rsa_min_bitlen

Field Documentation

uint32_t mbedtls_x509_crt_profile::allowed_mds

MDs for signatures

uint32_t mbedtls_x509_crt_profile::allowed_pks

PK algs for signatures

uint32_t mbedtls_x509_crt_profile::allowed_curves

Elliptic curves for ECDSA

uint32_t mbedtls_x509_crt_profile::rsa_min_bitlen

Minimum size for RSA keys

struct mbedtls_x509write_cert

Container for writing a certificate (CRT)

struct mbedtls_x509_crt_verify_chain_item

Item in a verification chain: cert and flags for it

struct mbedtls_x509_crt_verify_chain

Verification chain as built by mbedtls_crt_verify_chain()

struct mbedtls_x509_csr

Certificate Signing Request (CSR) structure.

Data Fields
mbedtls_x509_buf	raw

mbedtls_x509_buf	cri

int	version

mbedtls_x509_buf	subject_raw

mbedtls_x509_name	subject

mbedtls_pk_context	pk

mbedtls_md_type_t	sig_md

mbedtls_pk_type_t	sig_pk

void *	sig_opts

Field Documentation

mbedtls_x509_buf mbedtls_x509_csr::raw

The raw CSR data (DER).

mbedtls_x509_buf mbedtls_x509_csr::cri

The raw CertificateRequestInfo body (DER).

int mbedtls_x509_csr::version

CSR version (1=v1).

mbedtls_x509_buf mbedtls_x509_csr::subject_raw

The raw subject data (DER).

mbedtls_x509_name mbedtls_x509_csr::subject

The parsed subject data (named information object).

mbedtls_pk_context mbedtls_x509_csr::pk

Container for the public key context.

mbedtls_md_type_t mbedtls_x509_csr::sig_md

Internal representation of the MD algorithm of the signature algorithm, e.g. MBEDTLS_MD_SHA256

mbedtls_pk_type_t mbedtls_x509_csr::sig_pk

Internal representation of the Public Key algorithm of the signature algorithm, e.g. MBEDTLS_PK_RSA

void* mbedtls_x509_csr::sig_opts

Signature options to be passed to mbedtls_pk_verify_ext(), e.g. for RSASSA-PSS

struct mbedtls_x509write_csr

Container for writing a CSR

Macro Definition Documentation

#define MBEDTLS_X509_MAX_INTERMEDIATE_CA 8

Maximum number of intermediate CAs in a verification chain. That is, maximum length of the chain, excluding the end-entity certificate and the trusted root certificate.

Set this to a low value to prevent an adversary from making you waste resources verifying an overlong certificate chain.

#define MBEDTLS_ERR_X509_FEATURE_UNAVAILABLE -0x2080

Unavailable feature, e.g. RSA hashing/encryption combination.

#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. different type expected.

#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. (see mbedtls_x509_crt sig_oid)

#define MBEDTLS_ERR_X509_CERT_VERIFY_FAILED -0x2700

Certificate verification failed, e.g. CRL, CA or signature check failed.

#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 occured, eg the chain is too long or the vrfy callback failed.

#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).

#define MBEDTLS_X509_ID_FLAG ( id ) ( 1 << ( (id) - 1 ) )

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

#define MBEDTLS_X509_MAX_VERIFY_CHAIN_SIZE ( MBEDTLS_X509_MAX_INTERMEDIATE_CA + 2 )

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

Typedef Documentation

typedef mbedtls_asn1_buf mbedtls_x509_buf

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

typedef mbedtls_asn1_bitstring mbedtls_x509_bitstring

Container for ASN1 bit strings.

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.).

typedef mbedtls_asn1_sequence mbedtls_x509_sequence

Container for a sequence of ASN.1 items

Function Documentation

int mbedtls_dhm_parse_dhm	(	mbedtls_dhm_context *	dhm,
		const unsigned char *	dhmin,
		size_t	dhminlen
	)

Parameters

dhm	The DHM context to import the DHM parameters into. This must be initialized.
dhmin	The input buffer. This must be a readable buffer of length `dhminlen` Bytes.
dhminlen	The size of the input buffer `dhmin`, including the terminating `NULL` Byte for PEM data.

Returns: 0 on success.; An MBEDTLS_ERR_DHM_XXX or MBEDTLS_ERR_PEM_XXX error code on failure.

int mbedtls_dhm_parse_dhmfile	(	mbedtls_dhm_context *	dhm,
		const char *	path
	)

Parameters

dhm	The DHM context to load the parameters to. This must be initialized.
path	The filename to read the DHM parameters from. This must not be `NULL`.

Returns: 0 on success.; An MBEDTLS_ERR_DHM_XXX or MBEDTLS_ERR_PEM_XXX error code on failure.

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

Parameters

chain	points to the start of the chain
buf	buffer holding the CRL data in DER format
buflen	size of the buffer (including the terminating null byte for PEM data)

Returns: 0 if successful, or a specific X509 or PEM error code

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

Note: Mutliple CRLs are accepted only if using PEM format

Parameters

chain	points to the start of the chain
buf	buffer holding the CRL data in PEM or DER format
buflen	size of the buffer (including the terminating null byte for PEM data)

Returns: 0 if successful, or a specific X509 or PEM error code

int mbedtls_x509_crl_parse_file	(	mbedtls_x509_crl *	chain,
		const char *	path
	)

Note: Mutliple CRLs are accepted only if using PEM format

Parameters

chain	points to the start of the chain
path	filename to read the CRLs from (in PEM or DER encoding)

Returns: 0 if successful, or a specific X509 or PEM error code

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

Parameters

buf	Buffer to write to
size	Maximum size of buffer
prefix	A line prefix
crl	The X509 CRL to represent

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

void mbedtls_x509_crl_init ( mbedtls_x509_crl * crl )

Parameters

crl	CRL chain to initialize

void mbedtls_x509_crl_free ( mbedtls_x509_crl * crl )

Parameters

crl	CRL chain to free

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

Parameters

chain	points to the start of the chain
buf	buffer holding the certificate DER data
buflen	size of the buffer

Returns: 0 if 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
	)

            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 \c 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.

Parameters

chain	The chain to which to add the parsed certificates.
buf	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.
buflen	The size of `buf`, including the terminating `NULL` byte in case of PEM encoded data.

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.

int mbedtls_x509_crt_parse_file	(	mbedtls_x509_crt *	chain,
		const char *	path
	)

Parameters

chain	points to the start of the chain
path	filename to read the certificates from

Returns: 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
	)

Parameters

chain	points to the start of the chain
path	directory / folder to read the certificate files from

Returns: 0 if all certificates parsed successfully, a positive number if partly successful or a specific X509 or PEM error code

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

Parameters

buf	Buffer to write to
size	Maximum size of buffer
prefix	A line prefix
crt	The X509 certificate to represent

Returns: 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
	)

Parameters

buf	Buffer to write to
size	Maximum size of buffer
prefix	A line prefix
flags	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.

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
	)

            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.

Parameters

crt	a certificate (chain) to be verified
trust_ca	the list of trusted CAs (see note above)
ca_crl	the list of CRLs for trusted CAs (see note above)
cn	expected Common Name (can be set to NULL if the CN must not be verified)
flags	result of the verification
f_vrfy	verification function
p_vrfy	verification parameter

Returns: 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_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
	)

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.

Parameters

crt	a certificate (chain) to be verified
trust_ca	the list of trusted CAs
ca_crl	the list of CRLs for trusted CAs
profile	security profile for verification
cn	expected Common Name (can be set to NULL if the CN must not be verified)
flags	result of the verification
f_vrfy	verification function
p_vrfy	verification parameter

Returns: 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_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
	)

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.

Parameters

crt	a certificate (chain) to be verified
trust_ca	the list of trusted CAs
ca_crl	the list of CRLs for trusted CAs
profile	security profile for verification
cn	expected Common Name (can be set to NULL if the CN must not be verified)
flags	result of the verification
f_vrfy	verification function
p_vrfy	verification parameter
rs_ctx	restart context (NULL to disable restart)

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().

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

Parameters

crt	Leaf certificate used.
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.

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().

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

Parameters

crt	Leaf certificate used.
usage_oid	Intended usage (eg MBEDTLS_OID_SERVER_AUTH or MBEDTLS_OID_CLIENT_AUTH).
usage_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.

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

Parameters

crt	a certificate to be verified
crl	the CRL to verify against

Returns: 1 if the certificate is revoked, 0 otherwise

void mbedtls_x509_crt_init ( mbedtls_x509_crt * crt )

Parameters

crt	Certificate chain to initialize

void mbedtls_x509_crt_free ( mbedtls_x509_crt * crt )

Parameters

crt	Certificate chain to free

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

Note: CSR attributes (if any) are currently silently ignored.

Parameters

csr	CSR context to fill
buf	buffer holding the CRL data
buflen	size of the buffer

Returns: 0 if successful, or a specific X509 error code

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

Note: See notes for mbedtls_x509_csr_parse_der()

Parameters

csr	CSR context to fill
buf	buffer holding the CRL data
buflen	size of the buffer (including the terminating null byte for PEM data)

Returns: 0 if successful, or a specific X509 or PEM error code

int mbedtls_x509_csr_parse_file	(	mbedtls_x509_csr *	csr,
		const char *	path
	)

Note: See notes for mbedtls_x509_csr_parse()

Parameters

csr	CSR context to fill
path	filename to read the CSR from

Returns: 0 if successful, or a specific X509 or PEM error code

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

Parameters

buf	Buffer to write to
size	Maximum size of buffer
prefix	A line prefix
csr	The X509 CSR to represent

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

void mbedtls_x509_csr_init ( mbedtls_x509_csr * csr )

Parameters

csr	CSR to initialize

void mbedtls_x509_csr_free ( mbedtls_x509_csr * csr )

Parameters

csr	CSR to free

Variable Documentation

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.

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 RSA-2048.

const mbedtls_x509_crt_profile mbedtls_x509_crt_profile_suiteb

NSA Suite B profile.

Overview

Data Structures

Macros

Functions

X509 Error codes

X509 Verify codes

Structures for parsing X.509 certificates, CRLs and CSRs

Structures and functions for parsing CRLs

Structures and functions for parsing and writing X.509 certificates

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

Data Structure Documentation

Data Fields

Field Documentation

Data Fields

Field Documentation

Data Fields

Field Documentation

Data Fields

Field Documentation

Data Fields

Field Documentation

Macro Definition Documentation

Typedef Documentation

Function Documentation

Variable Documentation