Data Channel Cryptography Module. More...

#include "crypto_backend.h"
#include "basic.h"
#include "buffer.h"
#include "packet_id.h"
#include "mtu.h"

Include dependency graph for crypto.h:

This graph shows which files directly or indirectly include this file:

Data Structures
struct	sha256_digest
	Wrapper struct to pass around SHA256 digests. More...

struct	key_type

struct	key
	Container for unidirectional cipher and HMAC key material. More...

struct	key_parameters
	internal structure similar to struct key that holds key information but is not represented on wire and can be changed/extended More...

struct	epoch_key

struct	key_ctx
	Container for one set of cipher and/or HMAC contexts. More...

struct	key2
	Container for bidirectional cipher and HMAC key material. More...

struct	key_direction_state
	Key ordering of the `key2.keys` array. More...

struct	key_ctx_bi
	Container for two sets of OpenSSL cipher and/or HMAC contexts for both sending and receiving directions. More...

struct	crypto_options
	Security parameter state for processing data channel packets. More...

Macros
#define	KEY_DIRECTION_BIDIRECTIONAL 0 /* same keys for both directions */

#define	KEY_DIRECTION_NORMAL 1 /* encrypt with keys[0], decrypt with keys[1] */

#define	KEY_DIRECTION_INVERSE 2 /* encrypt with keys[1], decrypt with keys[0] */

#define	CO_PACKET_ID_LONG_FORM (1<<0)
	Bit-flag indicating whether to use OpenVPN's long packet ID format.

#define	CO_IGNORE_PACKET_ID (1<<1)
	Bit-flag indicating whether to ignore the packet ID of a received packet.

#define	CO_MUTE_REPLAY_WARNINGS (1<<2)
	Bit-flag indicating not to display replay warnings.

#define	CO_USE_TLS_KEY_MATERIAL_EXPORT (1<<3)
	Bit-flag indicating that data channel key derivation is done using TLS keying material export [RFC5705].

#define	CO_RESEND_WKC (1<<4)
	Bit-flag indicating that the client is expected to resend the wrapped client key with the 2nd packet (packet-id 1) like with the HARD_RESET_CLIENT_V3 packet.

#define	CO_FORCE_TLSCRYPTV2_COOKIE (1<<5)
	Bit-flag indicating that we do not allow clients that do not support resending the wrapped client key (WKc) with the third packet of the three-way handshake.

#define	CO_USE_CC_EXIT_NOTIFY (1<<6)
	Bit-flag indicating that explicit exit notifies should be sent via the control channel instead of using an OCC message.

#define	CO_USE_DYNAMIC_TLS_CRYPT (1<<7)
	Bit-flag indicating that renegotiations are using tls-crypt with a TLS-EKM derived key.

#define	CO_EPOCH_DATA_KEY_FORMAT (1<<8)
	Bit-flag indicating the epoch the data format.

#define	CRYPT_ERROR_EXIT(flags, format) do { msg(flags, "%s: " format, error_prefix); goto error_exit; } while (false)

#define	CRYPT_ERROR(format) CRYPT_ERROR_EXIT(D_CRYPT_ERRORS, format)

#define	CRYPT_DROP(format) CRYPT_ERROR_EXIT(D_MULTI_DROPPED, format)

#define	OPENVPN_AEAD_MIN_IV_LEN (sizeof(packet_id_type) + 8)
	Minimal IV length for AEAD mode ciphers (in bytes): 4-byte packet id + 8 bytes implicit IV.

#define	RKF_MUST_SUCCEED (1<<0)

#define	RKF_INLINE (1<<1)

#define	AEAD_LIMIT_BLOCKSIZE 16
	Blocksize used for the AEAD limit caluclation.

Functions
void	key_parameters_from_key (struct key_parameters key_params, const struct key key)
	Converts a struct key representation into a struct key_parameters representation.

void	read_key_file (struct key2 key2, const char file, const unsigned int flags)

int	write_key_file (const int nkeys, const char *filename)
	Write nkeys 1024-bits keys to file.

bool	check_key (struct key key, const struct key_type kt)

void	init_key_type (struct key_type kt, const char ciphername, const char *authname, bool tls_mode, bool warn)
	Initialize a key_type structure with.

void	init_key_ctx (struct key_ctx ctx, const struct key_parameters key, const struct key_type kt, int enc, const char prefix)

void	init_key_bi_ctx_send (struct key_ctx ctx, const struct key_parameters key, const struct key_type kt, const char name)

void	init_key_bi_ctx_recv (struct key_ctx ctx, const struct key_parameters key, const struct key_type kt, const char name)

void	free_key_ctx (struct key_ctx *ctx)

void	init_key_ctx_bi (struct key_ctx_bi ctx, const struct key2 key2, int key_direction, const struct key_type kt, const char name)

void	free_key_ctx_bi (struct key_ctx_bi *ctx)

bool	crypto_check_replay (struct crypto_options opt, const struct packet_id_net pin, uint16_t epoch, const char error_prefix, struct gc_arena gc)
	Check packet ID for replay, and perform replay administration.

unsigned int	calculate_crypto_overhead (const struct key_type *kt, unsigned int pkt_id_size, bool occ)
	Calculate the maximum overhead that our encryption has on a packet.

unsigned int	crypto_max_overhead (void)
	Return the worst-case OpenVPN crypto overhead (in bytes)

void	write_pem_key_file (const char filename, const char key_name)
	Generate a server key with enough randomness to fill a key struct and write to file.

bool	generate_ephemeral_key (struct buffer key, const char pem_name)
	Generate ephermal key material into the key structure.

bool	read_pem_key_file (struct buffer key, const char pem_name, const char *key_file, bool key_inline)
	Read key material from a PEM encoded files into the key structure.

void	prng_bytes (uint8_t *output, int len)

long int	get_random (void)

void	print_cipher (const char *cipher)
	Print a cipher list entry.

void	test_crypto (struct crypto_options co, struct frame f)

void	key_direction_state_init (struct key_direction_state *kds, int key_direction)

void	verify_fix_key2 (struct key2 key2, const struct key_type kt, const char *shared_secret_file)

void	must_have_n_keys (const char filename, const char option, const struct key2 *key2, int n)

int	ascii2keydirection (int msglevel, const char *str)

const char *	keydirection2ascii (int kd, bool remote, bool humanreadable)

void	key2_print (const struct key2 k, const struct key_type kt, const char prefix0, const char prefix1)
	Prints the keys in a key2 structure.

void	crypto_read_openvpn_key (const struct key_type key_type, struct key_ctx_bi ctx, const char key_file, bool key_inline, const int key_direction, const char key_name, const char opt_name, struct key2 keydata)

int	memcmp_constant_time (const void a, const void b, size_t size)
	As memcmp(), but constant-time.

static bool	key_ctx_bi_defined (const struct key_ctx_bi *key)

const char *	print_key_filename (const char *str, bool is_inline)
	To be used when printing a string that may contain inline data.

static struct key_type	create_kt (const char cipher, const char md, const char *optname)
	Creates and validates an instance of struct key_type with the provided algs.

uint64_t	cipher_get_aead_limits (const char *ciphername)
	Check if the cipher is an AEAD cipher and needs to be limited to a certain number of number of blocks + packets.

static bool	cipher_decrypt_verify_fail_exceeded (const struct key_ctx *ctx)
	Check if the number of failed decryption is over the acceptable limit.

static bool	cipher_decrypt_verify_fail_warn (const struct key_ctx *ctx)
	Check if the number of failed decryption is approaching the limit and we should try to move to a new key.

bool	check_tls_prf_working (void)
	Checks if the current TLS library supports the TLS 1.0 PRF with MD5+SHA1 that OpenVPN uses when TLS Keying Material Export is not available.

static bool	aead_usage_limit_reached (const uint64_t limit, const struct key_ctx *key_ctx, int64_t higest_pid)
	Checks if the usage limit for an AEAD cipher is reached.

Functions for performing security operations on data channel packets
void	openvpn_encrypt (struct buffer buf, struct buffer work, struct crypto_options opt)
	Encrypt and HMAC sign a packet so that it can be sent as a data channel VPN tunnel packet to a remote OpenVPN peer.

bool	openvpn_decrypt (struct buffer buf, struct buffer work, struct crypto_options opt, const struct frame frame, const uint8_t ad_start)
	HMAC verify and decrypt a data channel packet received from a remote OpenVPN peer.

Detailed Description

Data Channel Cryptography Module.

Definition in file crypto.h.

Macro Definition Documentation

◆ AEAD_LIMIT_BLOCKSIZE

#define AEAD_LIMIT_BLOCKSIZE 16

Blocksize used for the AEAD limit caluclation.

Since cipher_ctx_block_size() is not reliable and will return 1 in many cases use a hardcoded blocksize instead

Definition at line 748 of file crypto.h.

◆ CO_EPOCH_DATA_KEY_FORMAT

#define CO_EPOCH_DATA_KEY_FORMAT (1<<8)

Bit-flag indicating the epoch the data format.

This format has the AEAD tag at the end of the packet and is using a longer 64-bit packet id that is split into a 16 bit epoch and 48 bit epoch counter

Definition at line 381 of file crypto.h.

◆ CO_FORCE_TLSCRYPTV2_COOKIE

#define CO_FORCE_TLSCRYPTV2_COOKIE (1<<5)

Bit-flag indicating that we do not allow clients that do not support resending the wrapped client key (WKc) with the third packet of the three-way handshake.

Definition at line 367 of file crypto.h.

◆ CO_IGNORE_PACKET_ID

#define CO_IGNORE_PACKET_ID (1<<1)

Bit-flag indicating whether to ignore the packet ID of a received packet.

This flag is used during processing of the first packet received from a client.

Definition at line 352 of file crypto.h.

◆ CO_MUTE_REPLAY_WARNINGS

#define CO_MUTE_REPLAY_WARNINGS (1<<2)

Bit-flag indicating not to display replay warnings.

Definition at line 355 of file crypto.h.

◆ CO_PACKET_ID_LONG_FORM

#define CO_PACKET_ID_LONG_FORM (1<<0)

Bit-flag indicating whether to use OpenVPN's long packet ID format.

Definition at line 346 of file crypto.h.

◆ CO_RESEND_WKC

#define CO_RESEND_WKC (1<<4)

Bit-flag indicating that the client is expected to resend the wrapped client key with the 2nd packet (packet-id 1) like with the HARD_RESET_CLIENT_V3 packet.

Definition at line 363 of file crypto.h.

◆ CO_USE_CC_EXIT_NOTIFY

#define CO_USE_CC_EXIT_NOTIFY (1<<6)

Bit-flag indicating that explicit exit notifies should be sent via the control channel instead of using an OCC message.

Definition at line 371 of file crypto.h.

◆ CO_USE_DYNAMIC_TLS_CRYPT

#define CO_USE_DYNAMIC_TLS_CRYPT (1<<7)

Bit-flag indicating that renegotiations are using tls-crypt with a TLS-EKM derived key.

Definition at line 375 of file crypto.h.

◆ CO_USE_TLS_KEY_MATERIAL_EXPORT

#define CO_USE_TLS_KEY_MATERIAL_EXPORT (1<<3)

Bit-flag indicating that data channel key derivation is done using TLS keying material export [RFC5705].

Definition at line 359 of file crypto.h.

◆ CRYPT_DROP

#define CRYPT_DROP ( format ) CRYPT_ERROR_EXIT(D_MULTI_DROPPED, format)

Definition at line 391 of file crypto.h.

◆ CRYPT_ERROR

#define CRYPT_ERROR ( format ) CRYPT_ERROR_EXIT(D_CRYPT_ERRORS, format)

Definition at line 390 of file crypto.h.

◆ CRYPT_ERROR_EXIT

#define CRYPT_ERROR_EXIT	(	flags,
		format
	)	do { msg(flags, "%s: " format, error_prefix); goto error_exit; } while (false)

Definition at line 387 of file crypto.h.

◆ KEY_DIRECTION_BIDIRECTIONAL

#define KEY_DIRECTION_BIDIRECTIONAL 0 /* same keys for both directions */

Definition at line 230 of file crypto.h.

◆ KEY_DIRECTION_INVERSE

#define KEY_DIRECTION_INVERSE 2 /* encrypt with keys[1], decrypt with keys[0] */

Definition at line 232 of file crypto.h.

◆ KEY_DIRECTION_NORMAL

#define KEY_DIRECTION_NORMAL 1 /* encrypt with keys[0], decrypt with keys[1] */

Definition at line 231 of file crypto.h.

◆ OPENVPN_AEAD_MIN_IV_LEN

#define OPENVPN_AEAD_MIN_IV_LEN (sizeof(packet_id_type) + 8)

Minimal IV length for AEAD mode ciphers (in bytes): 4-byte packet id + 8 bytes implicit IV.

Definition at line 397 of file crypto.h.

◆ RKF_INLINE

#define RKF_INLINE (1<<1)

Definition at line 400 of file crypto.h.

◆ RKF_MUST_SUCCEED

#define RKF_MUST_SUCCEED (1<<0)

Definition at line 399 of file crypto.h.

Function Documentation

◆ aead_usage_limit_reached()

static bool aead_usage_limit_reached	(	const uint64_t	limit,
		const struct key_ctx *	key_ctx,
		int64_t	higest_pid
	)

inlinestatic

Checks if the usage limit for an AEAD cipher is reached.

This method abstracts the calculation to make the calling function easier to read.

Definition at line 765 of file crypto.h.

References key_ctx::plaintext_blocks.

Referenced by check_aead_limits(), epoch_check_send_iterate(), and should_trigger_renegotiation().

◆ ascii2keydirection()

int ascii2keydirection	(	int	msglevel,
		const char *	str
	)

Definition at line 1653 of file crypto.c.

References KEY_DIRECTION_BIDIRECTIONAL, KEY_DIRECTION_INVERSE, KEY_DIRECTION_NORMAL, and msg.

Referenced by add_option().

◆ calculate_crypto_overhead()

unsigned int calculate_crypto_overhead	(	const struct key_type *	kt,
		unsigned int	pkt_id_size,
		bool	occ
	)

Calculate the maximum overhead that our encryption has on a packet.

This does not include needed additional buffer size

This does NOT include the padding and rounding of CBC size as the users (mssfix/fragment) of this function need to adjust for this and add it themselves.

Parameters

kt	Struct with the crypto algorithm to use
pkt_id_size	Size of the packet id
occ	if true calculates the overhead for crypto in the same incorrect way as all previous OpenVPN versions did, to end up with identical numbers for OCC compatibility

Definition at line 819 of file crypto.c.

References key_type::cipher, cipher_defined(), cipher_kt_block_size(), cipher_kt_iv_size(), cipher_kt_mode_aead(), cipher_kt_mode_cbc(), cipher_kt_tag_size(), key_type::digest, buffer::len, md_defined(), and md_kt_size().

Referenced by frame_calculate_protocol_header_size().

◆ check_key()

bool check_key	(	struct key *	key,
		const struct key_type *	kt
	)

Definition at line 1151 of file crypto.c.

References key_type::cipher, cipher_defined(), and key_is_zero().

Referenced by generate_key_expansion(), and verify_fix_key2().

◆ check_tls_prf_working()

bool check_tls_prf_working ( void )

Checks if the current TLS library supports the TLS 1.0 PRF with MD5+SHA1 that OpenVPN uses when TLS Keying Material Export is not available.

Returns: true if supported, false otherwise.

Definition at line 1941 of file crypto.c.

References ssl_tls1_PRF().

Referenced by options_process_mutate_prf().

◆ cipher_decrypt_verify_fail_exceeded()

static bool cipher_decrypt_verify_fail_exceeded ( const struct key_ctx * ctx )

inlinestatic

Check if the number of failed decryption is over the acceptable limit.

Definition at line 721 of file crypto.h.

References key_ctx::failed_verifications.

Referenced by openvpn_decrypt_aead().

◆ cipher_decrypt_verify_fail_warn()

static bool cipher_decrypt_verify_fail_warn ( const struct key_ctx * ctx )

inlinestatic

Check if the number of failed decryption is approaching the limit and we should try to move to a new key.

Definition at line 736 of file crypto.h.

References key_ctx::failed_verifications.

Referenced by epoch_check_send_iterate(), and should_trigger_renegotiation().

◆ cipher_get_aead_limits()

uint64_t cipher_get_aead_limits ( const char * ciphername )

Check if the cipher is an AEAD cipher and needs to be limited to a certain number of number of blocks + packets.

Return 0 if ciphername is not an AEAD cipher or no limit (e.g. Chacha20-Poly1305) is needed. (Or the limit is larger than 2^64)

For reference see the OpenVPN RFC draft and https://www.ietf.org/archive/id/draft-irtf-cfrg-aead-limits-08.html

Definition at line 353 of file crypto.c.

References cipher_kt_mode_aead(), cipher_kt_name(), and buffer::len.

Referenced by crypto_test_aead_limits(), epoch_init_key_ctx(), and tls_get_limit_aead().

◆ create_kt()

static struct key_type create_kt	(	const char *	cipher,
		const char *	md,
		const char *	optname
	)

inlinestatic

Creates and validates an instance of struct key_type with the provided algs.

Parameters

cipher	the cipher algorithm to use (must be a string literal)
md	the digest algorithm to use (must be a string literal)
optname	the name of the option requiring the key_type object

Returns: the initialized key_type instance

Definition at line 685 of file crypto.h.

References key_type::cipher, cipher_defined(), cipher_valid(), key_type::digest, M_WARN, md_defined(), md_valid(), and msg.

Referenced by auth_token_kt(), init_crypto_options(), and tls_crypt_kt().

◆ crypto_check_replay()

bool crypto_check_replay	(	struct crypto_options *	opt,
		const struct packet_id_net *	pin,
		uint16_t	epoch,
		const char *	error_prefix,
		struct gc_arena *	gc
	)

Check packet ID for replay, and perform replay administration.

Parameters

opt	Crypto options for this packet, contains replay state.
pin	Packet ID read from packet.
epoch	Epoch read from packet or 0 when epoch is not used.
error_prefix	Prefix to use when printing error messages.
gc	Garbage collector to use.

Returns: true if packet ID is validated to be not a replay, false otherwise.

Definition at line 384 of file crypto.c.

References CO_MUTE_REPLAY_WARNINGS, CO_PACKET_ID_LONG_FORM, D_GENKEY, D_REPLAY_ERRORS, key_ctx_bi::decrypt, key_ctx::epoch, epoch_replace_update_recv_key(), crypto_options::epoch_retiring_data_receive_key, crypto_options::epoch_retiring_key_pid_recv, crypto_options::flags, gc, crypto_options::key_ctx_bi, msg, crypto_options::packet_id, packet_id_add(), packet_id_net_print(), packet_id_persist_save_obj(), packet_id_reap_test(), packet_id_test(), crypto_options::pid_persist, and packet_id::rec.

Referenced by openvpn_decrypt_aead(), openvpn_decrypt_v1(), and tls_crypt_unwrap().

◆ crypto_max_overhead()

unsigned int crypto_max_overhead ( void )

Return the worst-case OpenVPN crypto overhead (in bytes)

Definition at line 868 of file crypto.c.

References max_int(), OPENVPN_AEAD_TAG_LENGTH, OPENVPN_MAX_CIPHER_BLOCK_SIZE, OPENVPN_MAX_HMAC_SIZE, OPENVPN_MAX_IV_LENGTH, and packet_id_size().

Referenced by frame_finalize_options().

◆ crypto_read_openvpn_key()

void crypto_read_openvpn_key	(	const struct key_type *	key_type,
		struct key_ctx_bi *	ctx,
		const char *	key_file,
		bool	key_inline,
		const int	key_direction,
		const char *	key_name,
		const char *	opt_name,
		struct key2 *	keydata
	)

Definition at line 1321 of file crypto.c.

References init_key_ctx_bi(), key2, key_direction_state_init(), M_ERR, msg, must_have_n_keys(), key2::n, key_direction_state::need_keys, print_key_filename(), read_key_file(), RKF_INLINE, RKF_MUST_SUCCEED, secure_memzero(), and verify_fix_key2().

Referenced by do_init_crypto_static(), do_init_tls_wrap_key(), init_tas_auth(), and tls_crypt_init_key().

◆ free_key_ctx()

void free_key_ctx ( struct key_ctx * ctx )

◆ free_key_ctx_bi()

void free_key_ctx_bi ( struct key_ctx_bi * ctx )

◆ generate_ephemeral_key()

bool generate_ephemeral_key	(	struct buffer *	key,
		const char *	pem_name
	)

Generate ephermal key material into the key structure.

Parameters

key	the key structure that will hold the key material
pem_name	the name used for logging

Returns: true if key generation was successful

Definition at line 1884 of file crypto.c.

References BCAP, BEND, buf_inc_len(), buffer::len, M_INFO, M_WARN, msg, and rand_bytes().

Referenced by auth_token_init_secret().

◆ get_random()

long int get_random ( void )

Definition at line 1757 of file crypto.c.

References prng_bytes().

Referenced by check_send_occ_msg_dowork(), check_timeout_random_component_dowork(), do_init_crypto_tls(), fragment_init(), gen_nonce(), init_connection_list(), multi_init(), packet_id_add(), and platform_create_temp_file().

◆ init_key_bi_ctx_recv()

void init_key_bi_ctx_recv	(	struct key_ctx *	ctx,
		const struct key_parameters *	key,
		const struct key_type *	kt,
		const char *	name
	)

Definition at line 1075 of file crypto.c.

References key_parameters::epoch, key_ctx::epoch, init_key_ctx(), key_ctx_update_implicit_iv(), and OPENVPN_OP_DECRYPT.

Referenced by epoch_init_recv_key(), and init_key_ctx_bi().

◆ init_key_bi_ctx_send()

void init_key_bi_ctx_send	(	struct key_ctx *	ctx,
		const struct key_parameters *	key,
		const struct key_type *	kt,
		const char *	name
	)

Definition at line 1063 of file crypto.c.

References key_parameters::epoch, key_ctx::epoch, init_key_ctx(), key_ctx_update_implicit_iv(), and OPENVPN_OP_ENCRYPT.

Referenced by epoch_init_send_key_ctx(), and init_key_ctx_bi().

◆ init_key_ctx()

void init_key_ctx	(	struct key_ctx *	ctx,
		const struct key_parameters *	key,
		const struct key_type *	kt,
		int	enc,
		const char *	prefix
	)

◆ init_key_ctx_bi()

void init_key_ctx_bi	(	struct key_ctx_bi *	ctx,
		const struct key2 *	key2,
		int	key_direction,
		const struct key_type *	kt,
		const char *	name
	)

Definition at line 1087 of file crypto.c.

References key_ctx_bi::decrypt, key_ctx_bi::encrypt, key_direction_state::in_key, init_key_bi_ctx_recv(), init_key_bi_ctx_send(), key_ctx_bi::initialized, key_direction_state_init(), key_parameters_from_key(), key2::keys, and key_direction_state::out_key.

Referenced by crypto_read_openvpn_key(), init_crypto_options(), init_key_contexts(), test_tls_crypt_v2_setup(), tls_crypt_v2_load_client_key(), tls_crypt_v2_wrap_unwrap_wrong_key(), and tls_session_generate_dynamic_tls_crypt_key().

◆ init_key_type()

void init_key_type	(	struct key_type *	kt,
		const char *	ciphername,
		const char *	authname,
		bool	tls_mode,
		bool	warn
	)

Initialize a key_type structure with.

Parameters

kt	The struct key_type to initialize
ciphername	The name of the cipher to use
authname	The name of the HMAC digest to use
tls_mode	Specifies whether we are running in TLS mode, which allows more ciphers than static key mode.
warn	Print warnings when null cipher / auth is used.

Definition at line 893 of file crypto.c.

References ASSERT, key_type::cipher, cipher_kt_block_size(), cipher_kt_mode_aead(), cipher_kt_mode_cbc(), cipher_kt_mode_ofb_cfb(), cipher_valid(), CLEAR, key_type::digest, buffer::len, M_FATAL, M_WARN, md_kt_size(), msg, OPENVPN_MAX_CIPHER_BLOCK_SIZE, OPENVPN_MAX_HMAC_SIZE, and warn_insecure_key_type().

Referenced by calc_options_string_link_mtu(), crypto_test_epoch_setup(), do_init_crypto_none(), do_init_crypto_static(), do_init_crypto_tls_c1(), epoch_test_derive_data_key(), init_tas_auth(), options_string(), test_mssfix_mtu_calculation(), and tls_session_update_crypto_params_do_work().

◆ key2_print()

void key2_print	(	const struct key2 *	k,
		const struct key_type *	kt,
		const char *	prefix0,
		const char *	prefix1
	)

Prints the keys in a key2 structure.

Definition at line 1208 of file crypto.c.

References ASSERT, key_print(), key2::keys, and key2::n.

Referenced by generate_key_expansion().

◆ key_ctx_bi_defined()

static bool key_ctx_bi_defined ( const struct key_ctx_bi * key )

inlinestatic

Definition at line 657 of file crypto.h.

References key::cipher, and key::hmac.

Referenced by do_init_crypto_static().

◆ key_direction_state_init()

void key_direction_state_init	(	struct key_direction_state *	kds,
		int	key_direction
	)

Definition at line 1705 of file crypto.c.

References ASSERT, CLEAR, key_direction_state::in_key, KEY_DIRECTION_BIDIRECTIONAL, KEY_DIRECTION_INVERSE, KEY_DIRECTION_NORMAL, key_direction_state::need_keys, and key_direction_state::out_key.

Referenced by crypto_read_openvpn_key(), init_epoch_keys(), init_key_ctx_bi(), and tls_session_generate_dynamic_tls_crypt_key().

◆ key_parameters_from_key()

void key_parameters_from_key	(	struct key_parameters *	key_params,
		const struct key *	key
	)

Converts a struct key representation into a struct key_parameters representation.

Parameters

key_params	destination for the converted struct
key	source of the conversion

Definition at line 1219 of file crypto.c.

References key::cipher, key_parameters::cipher, key_parameters::cipher_size, CLEAR, key::hmac, key_parameters::hmac, key_parameters::hmac_size, MAX_CIPHER_KEY_LENGTH, and MAX_HMAC_KEY_LENGTH.

Referenced by auth_token_init_secret(), init_key_ctx_bi(), and tls_crypt_v2_init_server_key().

◆ keydirection2ascii()

const char * keydirection2ascii	(	int	kd,
		bool	remote,
		bool	humanreadable
	)

Definition at line 1676 of file crypto.c.

References ASSERT, KEY_DIRECTION_BIDIRECTIONAL, KEY_DIRECTION_INVERSE, and KEY_DIRECTION_NORMAL.

Referenced by options_string(), show_connection_entry(), and show_settings().

◆ memcmp_constant_time()

int memcmp_constant_time	(	const void *	a,
		const void *	b,
		size_t	size
	)

As memcmp(), but constant-time.

Returns 0 when data is equal, non-zero otherwise.

Definition at line 1346 of file crypto_openssl.c.

Referenced by check_hmac_token(), check_session_id_hmac(), is_auth_token(), man_check_password(), openvpn_decrypt_v1(), tls_crypt_unwrap(), tls_crypt_v2_unwrap_client_key(), verify_auth_token(), and verify_cert().

◆ must_have_n_keys()

void must_have_n_keys	(	const char *	filename,
		const char *	option,
		const struct key2 *	key2,
		int	n
	)

Definition at line 1640 of file crypto.c.

References M_FATAL, msg, and key2::n.

Referenced by crypto_read_openvpn_key().

◆ print_cipher()

void print_cipher ( const char * cipher )

Print a cipher list entry.

Definition at line 1769 of file crypto.c.

References cipher_kt_block_size(), cipher_kt_key_size(), cipher_kt_mode_cbc(), cipher_kt_name(), and cipher_valid_reason().

Referenced by show_available_ciphers().

◆ print_key_filename()

const char * print_key_filename	(	const char *	str,
		bool	is_inline
	)

To be used when printing a string that may contain inline data.

If "is_inline" is true, return the inline tag. If "is_inline" is false and "str" is not NULL, return "str". Return the constant string "[NULL]" otherwise.

Parameters

str	the original string to return when is_inline is false
is_inline	true when str contains an inline data of some sort

Definition at line 1310 of file crypto.c.

References buffer::len, and np().

Referenced by backend_tls_ctx_reload_crl(), crypto_read_openvpn_key(), read_key_file(), tls_ctx_load_ca(), tls_ctx_load_dh_params(), tls_ctx_load_extra_certs(), and tls_ctx_load_priv_file().

◆ prng_bytes()

void prng_bytes	(	uint8_t *	output,
		int	len
	)

Definition at line 1750 of file crypto.c.

References ASSERT, and rand_bytes().

Referenced by get_random(), hostname_randomize(), openvpn_encrypt_v1(), and session_id_random().

◆ read_key_file()

void read_key_file	(	struct key2 *	key2,
		const char *	file,
		const unsigned int	flags
	)

Definition at line 1373 of file crypto.c.

References ASSERT, buf_clear(), buf_set_read(), buf_valid(), buffer_read_from_file(), CLEAR, buffer::data, format_hex_ex(), gc, gc_free(), gc_new(), key2::keys, buffer::len, M_FATAL, M_INFO, msg, key2::n, PARSE_DATA, PARSE_DATA_COMPLETE, PARSE_FINISHED, PARSE_FOOT, PARSE_HEAD, PARSE_INITIAL, print_key_filename(), printable_char_fmt, RKF_INLINE, RKF_MUST_SUCCEED, SIZE, static_key_foot, static_key_head, and unprintable_char_fmt.

Referenced by crypto_read_openvpn_key().

◆ read_pem_key_file()

bool read_pem_key_file	(	struct buffer *	key,
		const char *	pem_name,
		const char *	key_file,
		bool	key_inline
	)

Read key material from a PEM encoded files into the key structure.

Parameters

key	the key structure that will hold the key material
pem_name	the name used in the pem encoding start/end lines
key_file	name of the file to read or the key itself if key_inline is true
key_inline	True if key_file contains an inline key, False otherwise.

Returns: true if reading into key was successful

Definition at line 1902 of file crypto.c.

References buf_clear(), buf_set_read(), buf_valid(), buffer_read_from_file(), cleanup(), crypto_pem_decode(), gc, gc_free(), gc_new(), buffer::len, M_WARN, and msg.

Referenced by auth_token_init_secret(), tls_crypt_v2_init_client_key(), and tls_crypt_v2_init_server_key().

◆ test_crypto()

void test_crypto	(	struct crypto_options *	co,
		struct frame *	f
	)

Definition at line 1229 of file crypto.c.

References alloc_buf_gc(), ASSERT, BLEN, BPTR, frame::buf, buf_init, BUF_SIZE, buf_write_alloc(), key_ctx::cipher, cipher_ctx_iv_length(), cipher_ctx_mode_aead(), clear_buf(), key_ctx_bi::decrypt, key_ctx_bi::encrypt, gc, gc_free(), gc_new(), frame::headroom, key_ctx::implicit_iv, crypto_options::key_ctx_bi, buffer::len, M_FATAL, M_INFO, msg, OPENVPN_AEAD_MIN_IV_LEN, openvpn_decrypt(), openvpn_encrypt(), OPENVPN_MAX_IV_LENGTH, frame::payload_size, rand_bytes(), and update_time().

Referenced by show_settings(), and test_crypto_thread().

◆ verify_fix_key2()

void verify_fix_key2	(	struct key2 *	key2,
		const struct key_type *	kt,
		const char *	shared_secret_file
	)

Definition at line 1734 of file crypto.c.

References check_key(), key2::keys, M_FATAL, msg, and key2::n.

Referenced by crypto_read_openvpn_key().

◆ write_key_file()

int write_key_file	(	const int	nkeys,
		const char *	filename
	)

Write nkeys 1024-bits keys to file.

Returns: number of random bits written, or -1 on failure.

Definition at line 1577 of file crypto.c.

References alloc_buf_gc(), BLEN, BPTR, buf_clear(), buf_printf(), buffer_write_file(), format_hex_ex(), gc, gc_free(), gc_new(), generate_key_random(), buffer::len, secure_memzero(), static_key_foot, and static_key_head.

Referenced by do_genkey().

◆ write_pem_key_file()

void write_pem_key_file	(	const char *	filename,
		const char *	key_name
	)

Generate a server key with enough randomness to fill a key struct and write to file.

Parameters

filename	Filename of the server key file to create.
key_name	The name to use in the PEM header/footer.

Definition at line 1846 of file crypto.c.

References BLEN, BPTR, buf_clear(), buf_set_read(), buffer_write_file(), cleanup(), clear_buf(), crypto_pem_encode(), gc, gc_free(), gc_new(), buffer::len, M_ERR, M_NONFATAL, M_WARN, msg, rand_bytes(), and secure_memzero().

Referenced by auth_token_write_server_key_file(), and tls_crypt_v2_write_server_key_file().

Data Structures

Macros

Functions

Detailed Description

Macro Definition Documentation

◆ AEAD_LIMIT_BLOCKSIZE

◆ CO_EPOCH_DATA_KEY_FORMAT

◆ CO_FORCE_TLSCRYPTV2_COOKIE

◆ CO_IGNORE_PACKET_ID

◆ CO_MUTE_REPLAY_WARNINGS

◆ CO_PACKET_ID_LONG_FORM

◆ CO_RESEND_WKC

◆ CO_USE_CC_EXIT_NOTIFY

◆ CO_USE_DYNAMIC_TLS_CRYPT

◆ CO_USE_TLS_KEY_MATERIAL_EXPORT

◆ CRYPT_DROP

◆ CRYPT_ERROR

◆ CRYPT_ERROR_EXIT

◆ KEY_DIRECTION_BIDIRECTIONAL

◆ KEY_DIRECTION_INVERSE

◆ KEY_DIRECTION_NORMAL

◆ OPENVPN_AEAD_MIN_IV_LEN

◆ RKF_INLINE

◆ RKF_MUST_SUCCEED

Function Documentation

◆ aead_usage_limit_reached()

◆ ascii2keydirection()

◆ calculate_crypto_overhead()

◆ check_key()

◆ check_tls_prf_working()

◆ cipher_decrypt_verify_fail_exceeded()

◆ cipher_decrypt_verify_fail_warn()

◆ cipher_get_aead_limits()

◆ create_kt()

◆ crypto_check_replay()

◆ crypto_max_overhead()

◆ crypto_read_openvpn_key()

◆ free_key_ctx()

◆ free_key_ctx_bi()

◆ generate_ephemeral_key()

◆ get_random()

◆ init_key_bi_ctx_recv()

◆ init_key_bi_ctx_send()

◆ init_key_ctx()

◆ init_key_ctx_bi()

◆ init_key_type()

◆ key2_print()

◆ key_ctx_bi_defined()

◆ key_direction_state_init()

◆ key_parameters_from_key()

◆ keydirection2ascii()

◆ memcmp_constant_time()

◆ must_have_n_keys()

◆ print_cipher()

◆ print_key_filename()

◆ prng_bytes()

◆ read_key_file()

◆ read_pem_key_file()

◆ test_crypto()

◆ verify_fix_key2()

◆ write_key_file()

◆ write_pem_key_file()