Detailed Description

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_san_other_name

struct	mbedtls_x509_subject_alternative_name

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

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

typedef struct mbedtls_x509_time	mbedtls_x509_time

Structures and functions for parsing CRLs
typedef struct mbedtls_x509_crl_entry	mbedtls_x509_crl_entry

typedef struct mbedtls_x509_crl	mbedtls_x509_crl

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 parsing and writing X.509 certificates
typedef struct mbedtls_x509_crt	mbedtls_x509_crt

typedef struct mbedtls_x509_san_other_name	mbedtls_x509_san_other_name

typedef struct mbedtls_x509_subject_alternative_name	mbedtls_x509_subject_alternative_name

typedef struct mbedtls_x509_crt_profile	mbedtls_x509_crt_profile

typedef struct mbedtls_x509write_cert	mbedtls_x509write_cert

typedef void	mbedtls_x509_crt_restart_ctx

#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)
typedef struct mbedtls_x509_csr	mbedtls_x509_csr

typedef struct mbedtls_x509write_csr	mbedtls_x509write_csr

Macro Definition Documentation

#define MBEDTLS_ERR_X509_ALLOC_FAILED -0x2880

Allocation of memory failed.

Definition at line 75 of file x509.h.

#define MBEDTLS_ERR_X509_BAD_INPUT_DATA -0x2800

Input invalid.

Definition at line 74 of file x509.h.

#define MBEDTLS_ERR_X509_BUFFER_TOO_SMALL -0x2980

Destination buffer is too small.

Definition at line 77 of file x509.h.

#define MBEDTLS_ERR_X509_CERT_UNKNOWN_FORMAT -0x2780

Format not recognized as DER or PEM.

Definition at line 73 of file x509.h.

#define MBEDTLS_ERR_X509_CERT_VERIFY_FAILED -0x2700

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

Definition at line 72 of file x509.h.

#define MBEDTLS_ERR_X509_FATAL_ERROR -0x3000

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

Definition at line 78 of file x509.h.

#define MBEDTLS_ERR_X509_FEATURE_UNAVAILABLE -0x2080

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

Definition at line 59 of file x509.h.

#define MBEDTLS_ERR_X509_FILE_IO_ERROR -0x2900

Read/write of file failed.

Definition at line 76 of file x509.h.

#define MBEDTLS_ERR_X509_INVALID_ALG -0x2300

The algorithm tag or value is invalid.

Definition at line 64 of file x509.h.

#define MBEDTLS_ERR_X509_INVALID_DATE -0x2400

The date tag or value is invalid.

Definition at line 66 of file x509.h.

#define MBEDTLS_ERR_X509_INVALID_EXTENSIONS -0x2500

The extension tag or value is invalid.

Definition at line 68 of file x509.h.

#define MBEDTLS_ERR_X509_INVALID_FORMAT -0x2180

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

Definition at line 61 of file x509.h.

#define MBEDTLS_ERR_X509_INVALID_NAME -0x2380

The name tag or value is invalid.

Definition at line 65 of file x509.h.

#define MBEDTLS_ERR_X509_INVALID_SERIAL -0x2280

The serial tag or value is invalid.

Definition at line 63 of file x509.h.

#define MBEDTLS_ERR_X509_INVALID_SIGNATURE -0x2480

The signature tag or value invalid.

Definition at line 67 of file x509.h.

#define MBEDTLS_ERR_X509_INVALID_VERSION -0x2200

The CRT/CRL/CSR version element is invalid.

Definition at line 62 of file x509.h.

#define MBEDTLS_ERR_X509_SIG_MISMATCH -0x2680

Signature algorithms do not match. (see mbedtls_x509_crt sig_oid)

Definition at line 71 of file x509.h.

#define MBEDTLS_ERR_X509_UNKNOWN_OID -0x2100

Requested OID is unknown.

Definition at line 60 of file x509.h.

#define MBEDTLS_ERR_X509_UNKNOWN_SIG_ALG -0x2600

Signature algorithm (oid) is unsupported.

Definition at line 70 of file x509.h.

#define MBEDTLS_ERR_X509_UNKNOWN_VERSION -0x2580

CRT/CRL/CSR has an unsupported version number.

Definition at line 69 of file x509.h.

#define MBEDTLS_X509_BADCERT_BAD_KEY 0x010000

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

Definition at line 102 of file x509.h.

#define MBEDTLS_X509_BADCERT_BAD_MD 0x4000

The certificate is signed with an unacceptable hash.

Definition at line 100 of file x509.h.

#define MBEDTLS_X509_BADCERT_BAD_PK 0x8000

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

Definition at line 101 of file x509.h.

#define MBEDTLS_X509_BADCERT_CN_MISMATCH 0x04

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

Definition at line 88 of file x509.h.

#define MBEDTLS_X509_BADCERT_EXPIRED 0x01

The certificate validity has expired.

Definition at line 86 of file x509.h.

#define MBEDTLS_X509_BADCERT_EXT_KEY_USAGE 0x1000

Usage does not match the extendedKeyUsage extension.

Definition at line 98 of file x509.h.

#define MBEDTLS_X509_BADCERT_FUTURE 0x0200

The certificate validity starts in the future.

Definition at line 95 of file x509.h.

#define MBEDTLS_X509_BADCERT_KEY_USAGE 0x0800

Usage does not match the keyUsage extension.

Definition at line 97 of file x509.h.

#define MBEDTLS_X509_BADCERT_MISSING 0x40

Certificate was missing.

Definition at line 92 of file x509.h.

#define MBEDTLS_X509_BADCERT_NOT_TRUSTED 0x08

The certificate is not correctly signed by the trusted CA.

Definition at line 89 of file x509.h.

#define MBEDTLS_X509_BADCERT_NS_CERT_TYPE 0x2000

Usage does not match the nsCertType extension.

Definition at line 99 of file x509.h.

#define MBEDTLS_X509_BADCERT_OTHER 0x0100

Other reason (can be used by verify callback)

Definition at line 94 of file x509.h.

#define MBEDTLS_X509_BADCERT_REVOKED 0x02

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

Definition at line 87 of file x509.h.

#define MBEDTLS_X509_BADCERT_SKIP_VERIFY 0x80

Certificate verification was skipped.

Definition at line 93 of file x509.h.

#define MBEDTLS_X509_BADCRL_BAD_KEY 0x080000

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

Definition at line 105 of file x509.h.

#define MBEDTLS_X509_BADCRL_BAD_MD 0x020000

The CRL is signed with an unacceptable hash.

Definition at line 103 of file x509.h.

#define MBEDTLS_X509_BADCRL_BAD_PK 0x040000

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

Definition at line 104 of file x509.h.

#define MBEDTLS_X509_BADCRL_EXPIRED 0x20

The CRL is expired.

Definition at line 91 of file x509.h.

#define MBEDTLS_X509_BADCRL_FUTURE 0x0400

The CRL is from the future

Definition at line 96 of file x509.h.

#define MBEDTLS_X509_BADCRL_NOT_TRUSTED 0x10

The CRL is not correctly signed by the trusted CA.

Definition at line 90 of file x509.h.

#define MBEDTLS_X509_CRT_VERSION_1 0

Definition at line 168 of file x509_crt.h.

#define MBEDTLS_X509_CRT_VERSION_2 1

Definition at line 169 of file x509_crt.h.

#define MBEDTLS_X509_CRT_VERSION_3 2

Definition at line 170 of file x509_crt.h.

#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.

Definition at line 152 of file x509_crt.h.

#define MBEDTLS_X509_MAX_FILE_PATH_LEN 512

Definition at line 176 of file x509_crt.h.

#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.

Definition at line 52 of file x509.h.

#define MBEDTLS_X509_MAX_VERIFY_CHAIN_SIZE ( MBEDTLS_X509_MAX_INTERMEDIATE_CA + 2 )

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

Definition at line 208 of file x509_crt.h.

#define MBEDTLS_X509_RFC5280_MAX_SERIAL_LEN 32

Definition at line 172 of file x509_crt.h.

#define MBEDTLS_X509_RFC5280_UTC_TIME_LEN 15

Definition at line 173 of file x509_crt.h.

Typedef Documentation

typedef mbedtls_asn1_bitstring mbedtls_x509_bitstring

Container for ASN1 bit strings.

Definition at line 216 of file x509.h.

typedef mbedtls_asn1_buf mbedtls_x509_buf

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

Definition at line 211 of file x509.h.

typedef struct mbedtls_x509_crl mbedtls_x509_crl

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

typedef struct mbedtls_x509_crl_entry mbedtls_x509_crl_entry

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

typedef struct mbedtls_x509_crt mbedtls_x509_crt

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

typedef struct mbedtls_x509_crt_profile mbedtls_x509_crt_profile

Security profile for certificate verification.

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

typedef void mbedtls_x509_crt_restart_ctx

Definition at line 258 of file x509_crt.h.

typedef struct mbedtls_x509_csr mbedtls_x509_csr

Certificate Signing Request (CSR) structure.

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.).

Definition at line 222 of file x509.h.

typedef struct mbedtls_x509_san_other_name mbedtls_x509_san_other_name

From RFC 5280 section 4.2.1.6: OtherName ::= SEQUENCE { type-id OBJECT IDENTIFIER, value [0] EXPLICIT ANY DEFINED BY type-id }

typedef mbedtls_asn1_sequence mbedtls_x509_sequence

Container for a sequence of ASN.1 items

Definition at line 227 of file x509.h.

typedef struct mbedtls_x509_subject_alternative_name mbedtls_x509_subject_alternative_name

A structure for holding the parsed Subject Alternative Name, according to type

typedef struct mbedtls_x509_time mbedtls_x509_time

Container for date and time (precision in seconds).

typedef struct mbedtls_x509write_cert mbedtls_x509write_cert

Container for writing a certificate (CRT)

typedef struct mbedtls_x509write_csr mbedtls_x509write_csr

Container for writing a CSR

Function Documentation

void mbedtls_x509_crl_free ( mbedtls_x509_crl * crl )

Unallocate all CRL data.

Parameters

crl CRL chain to free

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

`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 )

Initialize a CRL (chain)

Parameters

crl CRL chain to initialize

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.

Note: Multiple 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_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

`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

X.509 module

Detailed Description

Data Structures

Macros

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)

Macro Definition Documentation

Typedef Documentation

Function Documentation