SSL/TLS interface functions for OpenSSL. More...

#include "includes.h"
#include <openssl/ssl.h>
#include <openssl/err.h>
#include <openssl/pkcs12.h>
#include <openssl/x509v3.h>
#include <openssl/dsa.h>
#include <openssl/dh.h>
#include "common.h"
#include "crypto.h"
#include "sha1.h"
#include "sha256.h"
#include "tls.h"

Data Structures
struct	tls_context

struct	tls_data

struct	tls_connection

Macros
#define	OPENSSL_NO_ENGINE

#define	ERR_remove_thread_state(tid) ERR_remove_state(0)

Typedefs
typedef int	stack_index_t

Functions
void *	tls_init (const struct tls_config *conf)
	Initialize TLS library. More...

void	tls_deinit (void *ssl_ctx)
	Deinitialize TLS library. More...

int	tls_get_errors (void *ssl_ctx)
	Process pending errors. More...

struct tls_connection *	tls_connection_init (void *ssl_ctx)
	Initialize a new TLS connection. More...

void	tls_connection_deinit (void ssl_ctx, struct tls_connection conn)
	Free TLS connection data. More...

int	tls_connection_established (void ssl_ctx, struct tls_connection conn)
	Has the TLS connection been completed? More...

int	tls_connection_shutdown (void ssl_ctx, struct tls_connection conn)
	Shutdown TLS connection. More...

int	tls_global_set_verify (void *ssl_ctx, int check_crl)
	Set global certificate verification options. More...

int	tls_connection_set_verify (void ssl_ctx, struct tls_connection conn, int verify_peer, unsigned int flags, const u8 *session_ctx, size_t session_ctx_len)
	Set certificate verification options. More...

int	tls_connection_get_random (void ssl_ctx, struct tls_connection conn, struct tls_random *keys)
	Get random data from TLS connection. More...

int	tls_connection_prf (void tls_ctx, struct tls_connection conn, const char label, int server_random_first, int skip_keyblock, u8 out, size_t out_len)
	Use TLS-PRF to derive keying material. More...

struct wpabuf *	tls_connection_handshake (void ssl_ctx, struct tls_connection conn, const struct wpabuf in_data, struct wpabuf *appl_data)
	Process TLS handshake (client side) More...

struct wpabuf *	tls_connection_server_handshake (void tls_ctx, struct tls_connection conn, const struct wpabuf in_data, struct wpabuf *appl_data)
	Process TLS handshake (server side) More...

struct wpabuf *	tls_connection_encrypt (void tls_ctx, struct tls_connection conn, const struct wpabuf *in_data)
	Encrypt data into TLS tunnel. More...

struct wpabuf *	tls_connection_decrypt (void tls_ctx, struct tls_connection conn, const struct wpabuf *in_data)
	Decrypt data from TLS tunnel. More...

int	tls_connection_resumed (void ssl_ctx, struct tls_connection conn)
	Was session resumption used. More...

int	tls_connection_set_cipher_list (void tls_ctx, struct tls_connection conn, u8 *ciphers)
	Configure acceptable cipher suites. More...

int	tls_get_version (void ssl_ctx, struct tls_connection conn, char *buf, size_t buflen)
	Get the current TLS version number. More...

int	tls_get_cipher (void ssl_ctx, struct tls_connection conn, char *buf, size_t buflen)
	Get current cipher name. More...

int	tls_connection_enable_workaround (void ssl_ctx, struct tls_connection conn)
	Enable TLS workaround options. More...

int	tls_connection_get_failed (void ssl_ctx, struct tls_connection conn)
	Get connection failure status. More...

int	tls_connection_get_read_alerts (void ssl_ctx, struct tls_connection conn)
	Get connection read alert status. More...

int	tls_connection_get_write_alerts (void ssl_ctx, struct tls_connection conn)
	Get connection write alert status. More...

int	tls_connection_set_params (void tls_ctx, struct tls_connection conn, const struct tls_connection_params *params)
	Set TLS connection parameters. More...

int	tls_global_set_params (void tls_ctx, const struct tls_connection_params params)
	Set TLS parameters for all TLS connection. More...

int	tls_connection_set_session_ticket_cb (void tls_ctx, struct tls_connection conn, tls_session_ticket_cb cb, void *ctx)

int	tls_get_library_version (char *buf, size_t buf_len)

void	tls_connection_set_success_data (struct tls_connection conn, struct wpabuf data)

void	tls_connection_set_success_data_resumed (struct tls_connection *conn)

const struct wpabuf *	tls_connection_get_success_data (struct tls_connection *conn)

void	tls_connection_remove_session (struct tls_connection *conn)

Detailed Description

SSL/TLS interface functions for OpenSSL.

Function Documentation

struct wpabuf* tls_connection_decrypt	(	void *	tls_ctx,
		struct tls_connection *	conn,
		const struct wpabuf *	in_data
	)

Decrypt data from TLS tunnel.

Parameters

tls_ctx	TLS context data from tls_init()
conn	Connection context data from tls_connection_init()
in_data	Encrypted TLS data

Returns: Decrypted TLS data or NULL on failure

This function is used after TLS handshake has been completed successfully to receive data from the encrypted tunnel. The caller is responsible for freeing the returned output data.

void tls_connection_deinit	(	void *	tls_ctx,
		struct tls_connection *	conn
	)

Free TLS connection data.

Parameters

tls_ctx	TLS context data from tls_init()
conn	Connection context data from tls_connection_init()

Release all resources allocated for TLS connection.

int tls_connection_enable_workaround	(	void *	tls_ctx,
		struct tls_connection *	conn
	)

Enable TLS workaround options.

Parameters

tls_ctx	TLS context data from tls_init()
conn	Connection context data from tls_connection_init()

Returns: 0 on success, -1 on failure

This function is used to enable connection-specific workaround options for buffer SSL/TLS implementations.

struct wpabuf* tls_connection_encrypt	(	void *	tls_ctx,
		struct tls_connection *	conn,
		const struct wpabuf *	in_data
	)

Encrypt data into TLS tunnel.

Parameters

tls_ctx	TLS context data from tls_init()
conn	Connection context data from tls_connection_init()
in_data	Plaintext data to be encrypted

Returns: Encrypted TLS data or NULL on failure

This function is used after TLS handshake has been completed successfully to send data in the encrypted tunnel. The caller is responsible for freeing the returned output data.

int tls_connection_established	(	void *	tls_ctx,
		struct tls_connection *	conn
	)

Has the TLS connection been completed?

Parameters

tls_ctx	TLS context data from tls_init()
conn	Connection context data from tls_connection_init()

Returns: 1 if TLS connection has been completed, 0 if not.

int tls_connection_get_failed	(	void *	tls_ctx,
		struct tls_connection *	conn
	)

Get connection failure status.

Parameters

tls_ctx	TLS context data from tls_init()
conn	Connection context data from tls_connection_init()

Returns >0 if connection has failed, 0 if not.

int tls_connection_get_random	(	void *	tls_ctx,
		struct tls_connection *	conn,
		struct tls_random *	data
	)

Get random data from TLS connection.

Parameters

tls_ctx	TLS context data from tls_init()
conn	Connection context data from tls_connection_init()
data	Structure of client/server random data (filled on success)

Returns: 0 on success, -1 on failure

int tls_connection_get_read_alerts	(	void *	tls_ctx,
		struct tls_connection *	conn
	)

Get connection read alert status.

Parameters

tls_ctx	TLS context data from tls_init()
conn	Connection context data from tls_connection_init()

Returns: Number of times a fatal read (remote end reported error) has happened during this connection.

int tls_connection_get_write_alerts	(	void *	tls_ctx,
		struct tls_connection *	conn
	)

Get connection write alert status.

Parameters

tls_ctx	TLS context data from tls_init()
conn	Connection context data from tls_connection_init()

Returns: Number of times a fatal write (locally detected error) has happened during this connection.

struct wpabuf* tls_connection_handshake	(	void *	tls_ctx,
		struct tls_connection *	conn,
		const struct wpabuf *	in_data,
		struct wpabuf **	appl_data
	)

Process TLS handshake (client side)

Parameters

tls_ctx	TLS context data from tls_init()
conn	Connection context data from tls_connection_init()
in_data	Input data from TLS server
appl_data	Pointer to application data pointer, or NULL if dropped

Returns: Output data, NULL on failure

The caller is responsible for freeing the returned output data. If the final handshake message includes application data, this is decrypted and appl_data (if not NULL) is set to point this data. The caller is responsible for freeing appl_data.

This function is used during TLS handshake. The first call is done with in_data == NULL and the library is expected to return ClientHello packet. This packet is then send to the server and a response from server is given to TLS library by calling this function again with in_data pointing to the TLS message from the server.

If the TLS handshake fails, this function may return NULL. However, if the TLS library has a TLS alert to send out, that should be returned as the output data. In this case, tls_connection_get_failed() must return failure (> 0).

tls_connection_established() should return 1 once the TLS handshake has been completed successfully.

struct tls_connection* tls_connection_init ( void * tls_ctx )

Initialize a new TLS connection.

Parameters

tls_ctx TLS context data from tls_init()

Returns: Connection context data, conn for other function calls

int tls_connection_prf	(	void *	tls_ctx,
		struct tls_connection *	conn,
		const char *	label,
		int	server_random_first,
		int	skip_keyblock,
		u8 *	out,
		size_t	out_len
	)

Use TLS-PRF to derive keying material.

Parameters

tls_ctx	TLS context data from tls_init()
conn	Connection context data from tls_connection_init()
label	Label (e.g., description of the key) for PRF
server_random_first	seed is 0 = client_random\|server_random, 1 = server_random\|client_random
skip_keyblock	Skip TLS key block from the beginning of PRF output
out	Buffer for output data from TLS-PRF
out_len	Length of the output buffer

Returns: 0 on success, -1 on failure

tls_connection_prf() is required so that further keying material can be derived from the master secret. Example implementation of this function is in tls_prf_sha1_md5() when it is called with seed set to client_random|server_random (or server_random|client_random). For TLSv1.2 and newer, a different PRF is needed, though.

int tls_connection_resumed	(	void *	tls_ctx,
		struct tls_connection *	conn
	)

Was session resumption used.

Parameters

tls_ctx	TLS context data from tls_init()
conn	Connection context data from tls_connection_init()

Returns: 1 if current session used session resumption, 0 if not

struct wpabuf* tls_connection_server_handshake	(	void *	tls_ctx,
		struct tls_connection *	conn,
		const struct wpabuf *	in_data,
		struct wpabuf **	appl_data
	)

Process TLS handshake (server side)

Parameters

tls_ctx	TLS context data from tls_init()
conn	Connection context data from tls_connection_init()
in_data	Input data from TLS peer
appl_data	Pointer to application data pointer, or NULL if dropped

Returns: Output data, NULL on failure

The caller is responsible for freeing the returned output data.

int tls_connection_set_cipher_list	(	void *	tls_ctx,
		struct tls_connection *	conn,
		u8 *	ciphers
	)

Configure acceptable cipher suites.

Parameters

tls_ctx	TLS context data from tls_init()
conn	Connection context data from tls_connection_init()
ciphers	Zero (TLS_CIPHER_NONE) terminated list of allowed ciphers (TLS_CIPHER_*).

Returns: 0 on success, -1 on failure

int tls_connection_set_params	(	void *	tls_ctx,
		struct tls_connection *	conn,
		const struct tls_connection_params *	params
	)

Set TLS connection parameters.

Parameters

tls_ctx	TLS context data from tls_init()
conn	Connection context data from tls_connection_init()
params	Connection parameters

Returns: 0 on success, -1 on failure, TLS_SET_PARAMS_ENGINE_PRV_INIT_FAILED (-2) on error causing PKCS#11 engine failure, or TLS_SET_PARAMS_ENGINE_PRV_VERIFY_FAILED (-3) on failure to verify the PKCS#11 engine private key, or TLS_SET_PARAMS_ENGINE_PRV_BAD_PIN (-4) on PIN error causing PKCS#11 engine failure.

int tls_connection_set_verify	(	void *	tls_ctx,
		struct tls_connection *	conn,
		int	verify_peer,
		unsigned int	flags,
		const u8 *	session_ctx,
		size_t	session_ctx_len
	)

Set certificate verification options.

Parameters

tls_ctx	TLS context data from tls_init()
conn	Connection context data from tls_connection_init()
verify_peer	1 = verify peer certificate
flags	Connection flags (TLS_CONN_*)
session_ctx	Session caching context or NULL to use default
session_ctx_len	Length of session_ctx in bytes.

Returns: 0 on success, -1 on failure

int tls_connection_shutdown	(	void *	tls_ctx,
		struct tls_connection *	conn
	)

Shutdown TLS connection.

Parameters

tls_ctx	TLS context data from tls_init()
conn	Connection context data from tls_connection_init()

Returns: 0 on success, -1 on failure

Shutdown current TLS connection without releasing all resources. New connection can be started by using the same conn without having to call tls_connection_init() or setting certificates etc. again. The new connection should try to use session resumption.

void tls_deinit ( void * tls_ctx )

Deinitialize TLS library.

Parameters

tls_ctx TLS context data from tls_init()

Called once during program shutdown and once for each RSN pre-authentication session. If global library deinitialization is needed (i.e., one that is shared between both authentication types), the TLS library wrapper should maintain a reference counter and do global deinitialization only when moving from 1 to 0 references.

int tls_get_cipher	(	void *	tls_ctx,
		struct tls_connection *	conn,
		char *	buf,
		size_t	buflen
	)

Get current cipher name.

Parameters

tls_ctx	TLS context data from tls_init()
conn	Connection context data from tls_connection_init()
buf	Buffer for the cipher name
buflen	buf size

Returns: 0 on success, -1 on failure

Get the name of the currently used cipher.

int tls_get_errors ( void * tls_ctx )

Process pending errors.

Parameters

tls_ctx TLS context data from tls_init()

Returns: Number of found error, 0 if no errors detected.

Process all pending TLS errors.

int tls_get_version	(	void *	tls_ctx,
		struct tls_connection *	conn,
		char *	buf,
		size_t	buflen
	)

Get the current TLS version number.

Parameters

tls_ctx	TLS context data from tls_init()
conn	Connection context data from tls_connection_init()
buf	Buffer for returning the TLS version number
buflen	buf size

Returns: 0 on success, -1 on failure

Get the currently used TLS version number.

int tls_global_set_params	(	void *	tls_ctx,
		const struct tls_connection_params *	params
	)

Set TLS parameters for all TLS connection.

Parameters

tls_ctx	TLS context data from tls_init()
params	Global TLS parameters

Returns: 0 on success, -1 on failure, TLS_SET_PARAMS_ENGINE_PRV_INIT_FAILED (-2) on error causing PKCS#11 engine failure, or TLS_SET_PARAMS_ENGINE_PRV_VERIFY_FAILED (-3) on failure to verify the PKCS#11 engine private key, or TLS_SET_PARAMS_ENGINE_PRV_BAD_PIN (-4) on PIN error causing PKCS#11 engine failure.

int tls_global_set_verify	(	void *	tls_ctx,
		int	check_crl
	)

Set global certificate verification options.

Parameters

tls_ctx	TLS context data from tls_init()
check_crl	0 = do not verify CRLs, 1 = verify CRL for the user certificate, 2 = verify CRL for all certificates

Returns: 0 on success, -1 on failure

void* tls_init ( const struct tls_config * conf )

Initialize TLS library.

Parameters

conf	Configuration data for TLS library

Returns: Context data to be used as tls_ctx in calls to other functions, or NULL on failure.

Called once during program startup and once for each RSN pre-authentication session. In other words, there can be two concurrent TLS contexts. If global library initialization is needed (i.e., one that is shared between both authentication types), the TLS library wrapper should maintain a reference counter and do global initialization only when moving from 0 to 1 reference.

Data Structures

Macros

Typedefs

Functions

Detailed Description

Function Documentation