SSL Structure

struct ssl_st
{
	/* protocol version
	 * (one of SSL2_VERSION, SSL3_VERSION, TLS1_VERSION)
	 */
 
int version;
	int type; /* SSL_ST_CONNECT or SSL_ST_ACCEPT */
 
	SSL_METHOD *method; /* SSLv3 */
 
 
	/* There are 2 BIO's even though they are normally both the
	 * same.  This is so data can be read and written to different
	 * handlers */
 
#ifndef NO_BIO
 
	BIO *rbio; /* used by SSL_read */
	BIO *wbio; /* used by SSL_write */
	BIO *bbio; /* used during session-id reuse to concatenate
		    * messages */
 
#else
 
	char *rbio; /* used by SSL_read */
	char *wbio; /* used by SSL_write */
	char *bbio;
#endif
 
	/* This holds a variable that indicates what we were doing
	 * when a 0 or -1 is returned.  This is needed for
	 * non-blocking IO so we know what request needs re-doing when
	 * in SSL_accept or SSL_connect */
 
	int rwstate;
 
	/* true when we are actually in SSL_accept() or SSL_connect() */
 
	int in_handshake;
	int (*handshake_func)();
 
	/* Imagine that here's a boolean member "init" that is
	 * switched as soon as SSL_set_{accept/connect}_state
	 * is called for the first time, so that "state" and
	 * "handshake_func" are properly initialized.  But as
	 * handshake_func is == 0 until then, we use this
	 * test instead of an "init" member.
	 */
 
	int server;	/* are we the server side? - mostly used by SSL_clear*/
	int new_session;/* 1 if we are to use a new session */
	int quiet_shutdown;/* don't send shutdown packets */
	int shutdown;	/* we have shut things down, 0x01 sent, 0x02
 
			 * for received */
 
	int state;	/* where we are */
	int rstate;	/* where we are when reading */
 
	BUF_MEM *init_buf;	/* buffer used during init */
	int init_num;		/* amount read/written */
	int init_off;		/* amount read/written */
 
	/* used internally to point at a raw packet */
 
	unsigned char *packet;
	unsigned int packet_length;
	struct ssl2_state_st *s2; /* SSLv2 variables */
	struct ssl3_state_st *s3; /* SSLv3 variables */
	int read_ahead;		/* Read as many input bytes as possible
	               	 	* (for non-blocking reads) */
 
	int hit;		/* reusing a previous session */
	int purpose;		/* Purpose setting */
	int trust;		/* Trust setting */
 
	/* crypto */
 
	STACK_OF(SSL_CIPHER) *cipher_list;
	STACK_OF(SSL_CIPHER) *cipher_list_by_id;
 
	/* These are the ones being used, the ones in SSL_SESSION are
	 * the ones to be 'copied' into these ones */
 
	EVP_CIPHER_CTX *enc_read_ctx;		/* cryptographic state */
	const EVP_MD *read_hash;		/* used for mac generation */
#ifndef NO_COMP
	COMP_CTX *expand;			/* uncompress */
#else
 
	char *expand;
#endif
 
	EVP_CIPHER_CTX *enc_write_ctx;		/* cryptographic state */
	const EVP_MD *write_hash;		/* used for mac generation */
#ifndef NO_COMP

	COMP_CTX *compress;			/* compression */
#else
	char *compress;	
#endif
 
	/* session info */
	/* client cert? */
	/* This is used to hold the server certificate used */
 
	struct cert_st /* CERT */ *cert;
 
	/* the session_id_context is used to ensure sessions are only reused
	 * in the appropriate context */
 
	unsigned int sid_ctx_length;
	unsigned char sid_ctx[SSL_MAX_SID_CTX_LENGTH];
 
	/* This can also be in the session once a session is established */
 
	SSL_SESSION *session;
 
	/* Used in SSL2 and SSL3 */
	int verify_mode; 	/* 0 don't care about verify failure.
				 * 1 fail if verify fails */
 
	int verify_depth;
	int (*verify_callback)(int ok,X509_STORE_CTX *ctx); /* fail if callback returns 0 */
	void (*info_callback)(); /* optional informational callback */
 
	int error;		/* error bytes to be written */
	int error_code;		/* actual code */
 
	SSL_CTX *ctx;
 
	/* set this flag to 1 and a sleep(1) is put into all SSL_read()
	 * and SSL_write() calls, good for nbio debuging :-) */
 
	int debug;	
 
	/* extra application data */
 
	long verify_result;
	CRYPTO_EX_DATA ex_data;
 
	/* for server side, keep the list of CA_dn we can use */
 
	STACK_OF(X509_NAME) *client_CA;
	int references;
	unsigned long options; /* protocol behaviour */
	unsigned long mode; /* API behaviour */
	int first_packet;
	int client_version;	/* what was passed, used for
 
				 * SSLv3/TLS rollback check */
 
};