wolfio.h File Reference

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Functions
int	EmbedReceive (WOLFSSL *ssl, char *buf, int sz, void *ctx)
	This function is the receive embedded callback. More...
int	EmbedSend (WOLFSSL *ssl, char *buf, int sz, void *ctx)
	This function is the send embedded callback. More...
int	EmbedReceiveFrom (WOLFSSL *ssl, char *buf, int sz, void *)
	This function is the receive embedded callback. More...
int	EmbedSendTo (WOLFSSL *ssl, char *buf, int sz, void *ctx)
	This function is the send embedded callback. More...
int	EmbedGenerateCookie (WOLFSSL *ssl, unsigned char *buf, int sz, void *)
	This function is the DTLS Generate Cookie callback. More...
void	EmbedOcspRespFree (void *ctx, byte *resp)
	This function frees the response buffer. More...
void	wolfSSL_CTX_SetIORecv (WOLFSSL_CTX *ctx, CallbackIORecv CBIORecv)
	This function registers a receive callback for wolfSSL to get input data. By default, wolfSSL uses EmbedReceive() as the callback which uses the system’s TCP recv() function. The user can register a function to get input from memory, some other network module, or from anywhere. Please see the EmbedReceive() function in src/io.c as a guide for how the function should work and for error codes. In particular, IO_ERR_WANT_READ should be returned for non blocking receive when no data is ready. More...
void	wolfSSL_SetIOReadCtx (WOLFSSL *ssl, void *ctx)
	This function registers a context for the SSL session’s receive callback function. By default, wolfSSL sets the file descriptor passed to wolfSSL_set_fd() as the context when wolfSSL is using the system’s TCP library. If you’ve registered your own receive callback you may want to set a specific context for the session. For example, if you’re using memory buffers the context may be a pointer to a structure describing where and how to access the memory buffers. More...
void	wolfSSL_SetIOWriteCtx (WOLFSSL *ssl, void *ctx)
	This function registers a context for the SSL session’s send callback function. By default, wolfSSL sets the file descriptor passed to wolfSSL_set_fd() as the context when wolfSSL is using the system’s TCP library. If you’ve registered your own send callback you may want to set a specific context for the session. For example, if you’re using memory buffers the context may be a pointer to a structure describing where and how to access the memory buffers. More...
void *	wolfSSL_GetIOReadCtx (WOLFSSL *ssl)
	This function returns the IOCB_ReadCtx member of the WOLFSSL struct. More...
void *	wolfSSL_GetIOWriteCtx (WOLFSSL *ssl)
	This function returns the IOCB_WriteCtx member of the WOLFSSL structure. More...
void	wolfSSL_SetIOReadFlags (WOLFSSL *ssl, int flags)
	This function sets the flags for the receive callback to use for the given SSL session. The receive callback could be either the default wolfSSL EmbedReceive callback, or a custom callback specified by the user (see wolfSSL_CTX_SetIORecv). The default flag value is set internally by wolfSSL to the value of 0. The default wolfSSL receive callback uses the recv() function to receive data from the socket. From the recv() man page: “The flags argument to a recv() function is formed by or'ing one or more of the values: MSG_OOB process out-of-band data, MSG_PEEK peek at incoming message, MSG_WAITALL wait for full request or error. The MSG_OOB flag requests receipt of out-of-band data that would not be received in the normal data stream. Some protocols place expedited data at the head of the normal data queue, and thus this flag cannot be used with such protocols. The MSG_PEEK flag causes the receive operation to return data from the beginning of the receive queue without removing that data from the queue. Thus, a subsequent receive call will return the same data. The MSG_WAITALL flag requests that the operation block until the full request is satisfied. However, the call may still return less data than requested if a signal is caught, an error or disconnect occurs, or the next data to be received is of a different type than that returned.” More...
void	wolfSSL_SetIOWriteFlags (WOLFSSL *ssl, int flags)
	This function sets the flags for the send callback to use for the given SSL session. The send callback could be either the default wolfSSL EmbedSend callback, or a custom callback specified by the user (see wolfSSL_CTX_SetIOSend). The default flag value is set internally by wolfSSL to the value of 0. The default wolfSSL send callback uses the send() function to send data from the socket. From the send() man page: “The flags parameter may include one or more of the following: #define MSG_OOB 0x1 // process out-of-band data, #define MSG_DONTROUTE 0x4 // bypass routing, use direct interface. The flag MSG_OOB is used to send 'out-of-band' data on sockets that support this notion (e.g. SOCK_STREAM); the underlying protocol must also support 'out-of-band' data. MSG_DONTROUTE is usually used only by diagnostic or routing programs.” More...
void	wolfSSL_SetIO_NetX (WOLFSSL *ssl, NX_TCP_SOCKET *nxsocket, ULONG waitoption)
	This function sets the nxSocket and nxWait members of the nxCtx struct within the WOLFSSL structure. More...
void	wolfSSL_CTX_SetGenCookie (WOLFSSL_CTX *ctx, CallbackGenCookie cb)
	This function sets the callback for the CBIOCookie member of the WOLFSSL_CTX structure. The CallbackGenCookie type is a function pointer and has the signature: int (CallbackGenCookie)(WOLFSSL ssl, unsigned char* buf, int sz, void* ctx);. More...
void *	wolfSSL_GetCookieCtx (WOLFSSL *ssl)
	This function returns the IOCB_CookieCtx member of the WOLFSSL structure. More...
int	wolfSSL_SetIO_ISOTP (WOLFSSL *ssl, isotp_wolfssl_ctx *ctx, can_recv_fn recv_fn, can_send_fn send_fn, can_delay_fn delay_fn, word32 receive_delay, char *receive_buffer, int receive_buffer_size, void *arg)
	This function sets up the ISO-TP context if wolfSSL, for use when wolfSSL is compiled with WOLFSSL_ISOTP. More...

Function Documentation

EmbedGenerateCookie()

int EmbedGenerateCookie	(	WOLFSSL *	ssl,
		unsigned char *	buf,
		int	sz,
		void *
	)

This function is the DTLS Generate Cookie callback.

Returns

Success This function returns the number of bytes copied into the buffer.

GEN_COOKIE_E returned if the getpeername failed in EmbedGenerateCookie.

Parameters

ssl	a pointer to a WOLFSSL structure, created using wolfSSL_new().
buf	byte pointer representing the buffer. It is the destination from XMEMCPY().
sz	the size of the buffer.
ctx	a void pointer to user registered context.

Example

WOLFSSL_CTX* ctx = wolfSSL_CTX_new( method );
WOLFSSL* ssl = wolfSSL_new(ctx);
byte buffer[BUFFER_SIZE];
int sz = sizeof(buffer)/sizeof(byte);
void* ctx;
…
int ret = EmbedGenerateCookie(ssl, buffer, sz, ctx);
 
if(ret > 0){
    // EmbedGenerateCookie code block for success
}

See also

wolfSSL_CTX_SetGenCookie

EmbedOcspRespFree()

void EmbedOcspRespFree	(	void *	ctx,
		byte *	resp
	)

This function frees the response buffer.

Returns

none No returns.

Parameters

ctx	a void pointer to heap hint.
resp	a byte pointer representing the response.

Example

void* ctx;
byte* resp; // Response buffer.
…
EmbedOcspRespFree(ctx, resp);

See also

wolfSSL_CertManagerSetOCSP_Cb

wolfSSL_CertManagerEnableOCSPStapling

wolfSSL_CertManagerEnableOCSP

EmbedReceive()

int EmbedReceive	(	WOLFSSL *	ssl,
		char *	buf,
		int	sz,
		void *	ctx
	)

This function is the receive embedded callback.

Returns

Success This function returns the number of bytes read.

WOLFSSL_CBIO_ERR_WANT_READ returned with a “Would block” message if the last error was SOCKET_EWOULDBLCOK or SOCKET_EAGAIN.

WOLFSSL_CBIO_ERR_TIMEOUT returned with a “Socket timeout” message.

WOLFSSL_CBIO_ERR_CONN_RST returned with a “Connection reset” message if the last error was SOCKET_ECONNRESET.

WOLFSSL_CBIO_ERR_ISR returned with a “Socket interrupted” message if the last error was SOCKET_EINTR.

WOLFSSL_CBIO_ERR_WANT_READ returned with a “Connection refused” message if the last error was SOCKET_ECONNREFUSED.

WOLFSSL_CBIO_ERR_CONN_CLOSE returned with a “Connection aborted” message if the last error was SOCKET_ECONNABORTED.

WOLFSSL_CBIO_ERR_GENERAL returned with a “General error” message if the last error was not specified.

Parameters

ssl	a pointer to a WOLFSSL structure, created using wolfSSL_new().
buf	a char pointer representation of the buffer.
sz	the size of the buffer.
ctx	a void pointer to user registered context. In the default case the ctx is a socket descriptor pointer.

Example

WOLFSSL_CTX* ctx = wolfSSL_CTX_new( protocol method );
WOLFSSL* ssl = wolfSSL_new(ctx);
char* buf;
int sz;
void* ctx;
int bytesRead = EmbedReceive(ssl, buf, sz, ctx);
if(bytesRead <= 0){
    // There were no bytes read. Failure case.
}

See also

EmbedSend

wolfSSL_CTX_SetIORecv

wolfSSL_SSLSetIORecv

EmbedReceiveFrom()

int EmbedReceiveFrom	(	WOLFSSL *	ssl,
		char *	buf,
		int	sz,
		void *
	)

This function is the receive embedded callback.

Returns

Success This function returns the nb bytes read if the execution was successful.

WOLFSSL_CBIO_ERR_WANT_READ if the connection refused or if a ‘would block’ error was thrown in the function.

WOLFSSL_CBIO_ERR_TIMEOUT returned if the socket timed out.

WOLFSSL_CBIO_ERR_CONN_RST returned if the connection reset.

WOLFSSL_CBIO_ERR_ISR returned if the socket was interrupted.

WOLFSSL_CBIO_ERR_GENERAL returned if there was a general error.

Parameters

ssl	a pointer to a WOLFSSL structure, created using wolfSSL_new().
buf	a constant char pointer to the buffer.
sz	an int type representing the size of the buffer.
ctx	a void pointer to the WOLFSSL_CTX context.

Example

WOLFSSL_CTX* ctx = wolfSSL_CTX_new( protocol method );
WOLFSSL* ssl = WOLFSSL_new(ctx);
char* buf;
int sz = sizeof(buf)/sizeof(char);
(void*)ctx;
…
int nb = EmbedReceiveFrom(ssl, buf, sz, ctx);
if(nb > 0){
    // nb is the number of bytes written and is positive
}

See also

EmbedSendTo

wolfSSL_CTX_SetIORecv

wolfSSL_SSLSetIORecv

wolfSSL_dtls_get_current_timeout

EmbedSend()

int EmbedSend	(	WOLFSSL *	ssl,
		char *	buf,
		int	sz,
		void *	ctx
	)

This function is the send embedded callback.

Returns

Success This function returns the number of bytes sent.

WOLFSSL_CBIO_ERR_WANT_WRITE returned with a “Would block” message if the last error was SOCKET_EWOULDBLOCK or SOCKET_EAGAIN.

WOLFSSL_CBIO_ERR_CONN_RST returned with a “Connection reset” message if the last error was SOCKET_ECONNRESET.

WOLFSSL_CBIO_ERR_ISR returned with a “Socket interrupted” message if the last error was SOCKET_EINTR.

WOLFSSL_CBIO_ERR_CONN_CLOSE returned with a “Socket EPIPE” message if the last error was SOCKET_EPIPE.

WOLFSSL_CBIO_ERR_GENERAL returned with a “General error” message if the last error was not specified.

Parameters

ssl	a pointer to a WOLFSSL structure, created using wolfSSL_new().
buf	a char pointer representing the buffer.
sz	the size of the buffer.
ctx	a void pointer to user registered context.

Example

WOLFSSL* ssl = wolfSSL_new(ctx);
char* buf;
int sz;
void* ctx;
int dSent = EmbedSend(ssl, buf, sz, ctx);
if(dSent <= 0){
    // No byes sent. Failure case.
}

See also

EmbedReceive

wolfSSL_CTX_SetIOSend

wolfSSL_SSLSetIOSend

EmbedSendTo()

int EmbedSendTo	(	WOLFSSL *	ssl,
		char *	buf,
		int	sz,
		void *	ctx
	)

This function is the send embedded callback.

Returns

Success This function returns the number of bytes sent.

WOLFSSL_CBIO_ERR_WANT_WRITE returned with a “Would Block” message if the last error was either SOCKET_EWOULDBLOCK or SOCKET_EAGAIN error.

WOLFSSL_CBIO_ERR_CONN_RST returned with a “Connection reset” message if the last error was SOCKET_ECONNRESET.

WOLFSSL_CBIO_ERR_ISR returned with a “Socket interrupted” message if the last error was SOCKET_EINTR.

WOLFSSL_CBIO_ERR_CONN_CLOSE returned with a “Socket EPIPE” message if the last error was WOLFSSL_CBIO_ERR_CONN_CLOSE.

WOLFSSL_CBIO_ERR_GENERAL returned with a “General error” message if the last error was not specified.

Parameters

ssl	a pointer to a WOLFSSL structure, created using wolfSSL_new().
buf	a char pointer representing the buffer.
sz	the size of the buffer.
ctx	a void pointer to the user registered context. The default case is a WOLFSSL_DTLS_CTX structure.

Example

WOLFSSL* ssl;
…
char* buf;
int sz;
void* ctx;
 
int sEmbed = EmbedSendto(ssl, buf, sz, ctx);
if(sEmbed <= 0){
    // No bytes sent. Failure case.
}

See also

EmbedReceiveFrom

wolfSSL_CTX_SetIOSend

wolfSSL_SSLSetIOSend

wolfSSL_CTX_SetGenCookie()

void wolfSSL_CTX_SetGenCookie	(	WOLFSSL_CTX *	ctx,
		CallbackGenCookie	cb
	)

This function sets the callback for the CBIOCookie member of the WOLFSSL_CTX structure. The CallbackGenCookie type is a function pointer and has the signature: int (CallbackGenCookie)(WOLFSSL ssl, unsigned char* buf, int sz, void* ctx);.

Returns

none No returns.

Parameters

ssl	a pointer to a WOLFSSL structure, created using wolfSSL_new().
cb	a CallbackGenCookie type function pointer with the signature of CallbackGenCookie.

Example

WOLFSSL_CTX* ctx = wolfSSL_CTX_new( method );
WOLFSSL* ssl = wolfSSL_new(ctx);
…
int SetGenCookieCB(WOLFSSL* ssl, unsigned char* buf, int sz, void* ctx){
// Callback function body.
}
…
wolfSSL_CTX_SetGenCookie(ssl->ctx, SetGenCookieCB);

See also

CallbackGenCookie

wolfSSL_CTX_SetIORecv()

void wolfSSL_CTX_SetIORecv	(	WOLFSSL_CTX *	ctx,
		CallbackIORecv	CBIORecv
	)

This function registers a receive callback for wolfSSL to get input data. By default, wolfSSL uses EmbedReceive() as the callback which uses the system’s TCP recv() function. The user can register a function to get input from memory, some other network module, or from anywhere. Please see the EmbedReceive() function in src/io.c as a guide for how the function should work and for error codes. In particular, IO_ERR_WANT_READ should be returned for non blocking receive when no data is ready.

Returns

none no Returns.

Parameters

ctx	pointer to the SSL context, created with wolfSSL_CTX_new().
callback	function to be registered as the receive callback for the wolfSSL context, ctx. The signature of this function must follow that as shown above in the Synopsis section.

Example

WOLFSSL_CTX* ctx = 0;
// Receive callback prototype
int MyEmbedReceive(WOLFSSL* ssl, char* buf, int sz, void* ctx);
// Register the custom receive callback with wolfSSL
wolfSSL_CTX_SetIORecv(ctx, MyEmbedReceive);
int MyEmbedReceive(WOLFSSL* ssl, char* buf, int sz, void* ctx)
{
    // custom EmbedReceive function
}

See also

wolfSSL_CTX_SetIOSend

wolfSSL_SetIOReadCtx

wolfSSL_SetIOWriteCtx

wolfSSL_SetIOReadCtx()

void wolfSSL_SetIOReadCtx	(	WOLFSSL *	ssl,
		void *	ctx
	)

This function registers a context for the SSL session’s receive callback function. By default, wolfSSL sets the file descriptor passed to wolfSSL_set_fd() as the context when wolfSSL is using the system’s TCP library. If you’ve registered your own receive callback you may want to set a specific context for the session. For example, if you’re using memory buffers the context may be a pointer to a structure describing where and how to access the memory buffers.

Returns

none No returns.

Parameters

ssl	pointer to the SSL session, created with wolfSSL_new().
rctx	pointer to the context to be registered with the SSL session’s (ssl) receive callback function.

Example

int sockfd;
WOLFSSL* ssl = 0;
...
// Manually setting the socket fd as the receive CTX, for example
wolfSSL_SetIOReadCtx(ssl, &sockfd);
...

See also

wolfSSL_CTX_SetIORecv

wolfSSL_CTX_SetIOSend

wolfSSL_SetIOWriteCtx

wolfSSL_SetIOReadFlags()

void wolfSSL_SetIOReadFlags	(	WOLFSSL *	ssl,
		int	flags
	)

This function sets the flags for the receive callback to use for the given SSL session. The receive callback could be either the default wolfSSL EmbedReceive callback, or a custom callback specified by the user (see wolfSSL_CTX_SetIORecv). The default flag value is set internally by wolfSSL to the value of 0. The default wolfSSL receive callback uses the recv() function to receive data from the socket. From the recv() man page: “The flags argument to a recv() function is formed by or'ing one or more of the values: MSG_OOB process out-of-band data, MSG_PEEK peek at incoming message, MSG_WAITALL wait for full request or error. The MSG_OOB flag requests receipt of out-of-band data that would not be received in the normal data stream. Some protocols place expedited data at the head of the normal data queue, and thus this flag cannot be used with such protocols. The MSG_PEEK flag causes the receive operation to return data from the beginning of the receive queue without removing that data from the queue. Thus, a subsequent receive call will return the same data. The MSG_WAITALL flag requests that the operation block until the full request is satisfied. However, the call may still return less data than requested if a signal is caught, an error or disconnect occurs, or the next data to be received is of a different type than that returned.”

Returns

none No returns.

Parameters

ssl	pointer to the SSL session, created with wolfSSL_new().
flags	value of the I/O read flags for the specified SSL session (ssl).

Example

WOLFSSL* ssl = 0;
...
// Manually setting recv flags to 0
wolfSSL_SetIOReadFlags(ssl, 0);
...

See also

wolfSSL_CTX_SetIORecv

wolfSSL_CTX_SetIOSend

wolfSSL_SetIOReadCtx

wolfSSL_SetIOWriteCtx()

void wolfSSL_SetIOWriteCtx	(	WOLFSSL *	ssl,
		void *	ctx
	)

This function registers a context for the SSL session’s send callback function. By default, wolfSSL sets the file descriptor passed to wolfSSL_set_fd() as the context when wolfSSL is using the system’s TCP library. If you’ve registered your own send callback you may want to set a specific context for the session. For example, if you’re using memory buffers the context may be a pointer to a structure describing where and how to access the memory buffers.

Returns

none No returns.

Parameters

ssl	pointer to the SSL session, created with wolfSSL_new().
wctx	pointer to the context to be registered with the SSL session’s (ssl) send callback function.

Example

int sockfd;
WOLFSSL* ssl = 0;
...
// Manually setting the socket fd as the send CTX, for example
wolfSSL_SetIOWriteCtx(ssl, &sockfd);
...

See also

wolfSSL_CTX_SetIORecv

wolfSSL_CTX_SetIOSend

wolfSSL_SetIOReadCtx

wolfSSL_SetIOWriteFlags()

void wolfSSL_SetIOWriteFlags	(	WOLFSSL *	ssl,
		int	flags
	)

This function sets the flags for the send callback to use for the given SSL session. The send callback could be either the default wolfSSL EmbedSend callback, or a custom callback specified by the user (see wolfSSL_CTX_SetIOSend). The default flag value is set internally by wolfSSL to the value of 0. The default wolfSSL send callback uses the send() function to send data from the socket. From the send() man page: “The flags parameter may include one or more of the following: #define MSG_OOB 0x1 // process out-of-band data, #define MSG_DONTROUTE 0x4 // bypass routing, use direct interface. The flag MSG_OOB is used to send 'out-of-band' data on sockets that support this notion (e.g. SOCK_STREAM); the underlying protocol must also support 'out-of-band' data. MSG_DONTROUTE is usually used only by diagnostic or routing programs.”

Returns

none No returns.

Parameters

ssl	pointer to the SSL session, created with wolfSSL_new().
flags	value of the I/O send flags for the specified SSL session (ssl).

Example

WOLFSSL* ssl = 0;
...
// Manually setting send flags to 0
wolfSSL_SetIOWriteFlags(ssl, 0);
...

See also

wolfSSL_CTX_SetIORecv

wolfSSL_CTX_SetIOSend

wolfSSL_SetIOReadCtx