/* Tunala ("Tunneler with a New Zealand accent") * * Written by Geoff Thorpe, but endorsed/supported by noone. Please use this is * if it's useful or informative to you, but it's only here as a scratchpad for * ideas about how you might (or might not) program with OpenSSL. If you deploy * this is in a mission-critical environment, and have not read, understood, * audited, and modified this code to your satisfaction, and the result is that * all hell breaks loose and you are looking for a new employer, then it proves * nothing except perhaps that Darwinism is alive and well. Let's just say, *I* * don't use this in a mission-critical environment, so it would be stupid for * anyone to assume that it is solid and/or tested enough when even its author * doesn't place that much trust in it. You have been warned. * * With thanks to Cryptographic Appliances, Inc. */ #ifndef _TUNALA_H #define _TUNALA_H #ifndef NO_SYSTEM_H #include #include #include #include #include #include #include #endif /* !defined(NO_SYSTEM_H) */ #ifndef NO_OPENSSL #include #include #include #endif /* !defined(NO_OPENSSL) */ #ifndef OPENSSL_NO_BUFFER /* This is the generic "buffer" type that is used when feeding the * state-machine. It's basically a FIFO with respect to the "adddata" & * "takedata" type functions that operate on it. */ #define MAX_DATA_SIZE 16384 typedef struct _buffer_t { unsigned char data[MAX_DATA_SIZE]; unsigned int used; /* Statistical values - counts the total number of bytes read in and * read out (respectively) since "buffer_init()" */ unsigned long total_in, total_out; } buffer_t; /* Initialise a buffer structure before use */ void buffer_init(buffer_t *buf); /* Cleanup a buffer structure - presently not needed, but if buffer_t is * converted to using dynamic allocation, this would be required - so should be * called to protect against an explosion of memory leaks later if the change is * made. */ void buffer_close(buffer_t *buf); /* Basic functions to manipulate buffers */ unsigned int buffer_used(buffer_t *buf); /* How much data in the buffer */ unsigned int buffer_unused(buffer_t *buf); /* How much space in the buffer */ int buffer_full(buffer_t *buf); /* Boolean, is it full? */ int buffer_notfull(buffer_t *buf); /* Boolean, is it not full? */ int buffer_empty(buffer_t *buf); /* Boolean, is it empty? */ int buffer_notempty(buffer_t *buf); /* Boolean, is it not empty? */ unsigned long buffer_total_in(buffer_t *buf); /* Total bytes written to buffer */ unsigned long buffer_total_out(buffer_t *buf); /* Total bytes read from buffer */ #if 0 /* Currently used only within buffer.c - better to expose only * higher-level functions anyway */ /* Add data to the tail of the buffer, returns the amount that was actually * added (so, you need to check if return value is less than size) */ unsigned int buffer_adddata(buffer_t *buf, const unsigned char *ptr, unsigned int size); /* Take data from the front of the buffer (and scroll the rest forward). If * "ptr" is NULL, this just removes data off the front of the buffer. Return * value is the amount actually removed (can be less than size if the buffer has * too little data). */ unsigned int buffer_takedata(buffer_t *buf, unsigned char *ptr, unsigned int size); /* Flushes as much data as possible out of the "from" buffer into the "to" * buffer. Return value is the amount moved. The amount moved can be restricted * to a maximum by specifying "cap" - setting it to -1 means no limit. */ unsigned int buffer_tobuffer(buffer_t *to, buffer_t *from, int cap); #endif #ifndef NO_IP /* Read or write between a file-descriptor and a buffer */ int buffer_from_fd(buffer_t *buf, int fd); int buffer_to_fd(buffer_t *buf, int fd); #endif /* !defined(NO_IP) */ #ifndef NO_OPENSSL /* Read or write between an SSL or BIO and a buffer */ void buffer_from_SSL(buffer_t *buf, SSL *ssl); void buffer_to_SSL(buffer_t *buf, SSL *ssl); void buffer_from_BIO(buffer_t *buf, BIO *bio); void buffer_to_BIO(buffer_t *buf, BIO *bio); /* Callbacks */ void cb_ssl_info(SSL *s, int where, int ret); void cb_ssl_info_set_output(FILE *fp); /* Called if output should be sent too */ int cb_ssl_verify(int ok, X509_STORE_CTX *ctx); void cb_ssl_verify_set_output(FILE *fp); void cb_ssl_verify_set_depth(unsigned int verify_depth); void cb_ssl_verify_set_level(unsigned int level); #endif /* !defined(NO_OPENSSL) */ #endif /* !defined(OPENSSL_NO_BUFFER) */ #ifndef NO_TUNALA #ifdef OPENSSL_NO_BUFFER #error "TUNALA section of tunala.h requires BUFFER support" #endif typedef struct _state_machine_t { SSL *ssl; BIO *bio_intossl; BIO *bio_fromssl; buffer_t clean_in, clean_out; buffer_t dirty_in, dirty_out; } state_machine_t; typedef enum { SM_CLEAN_IN, SM_CLEAN_OUT, SM_DIRTY_IN, SM_DIRTY_OUT } sm_buffer_t; void state_machine_init(state_machine_t *machine); void state_machine_close(state_machine_t *machine); buffer_t *state_machine_get_buffer(state_machine_t *machine, sm_buffer_t type); SSL *state_machine_get_SSL(state_machine_t *machine); int state_machine_set_SSL(state_machine_t *machine, SSL *ssl, int is_server); /* Performs the data-IO loop and returns zero if the machine should close */ int state_machine_churn(state_machine_t *machine); /* Is used to handle closing conditions - namely when one side of the tunnel has * closed but the other should finish flushing. */ int state_machine_close_clean(state_machine_t *machine); int state_machine_close_dirty(state_machine_t *machine); #endif /* !defined(NO_TUNALA) */ #ifndef NO_IP /* Initialise anything related to the networking. This includes blocking pesky * SIGPIPE signals. */ int ip_initialise(void); /* ip is the 4-byte ip address (eg. 127.0.0.1 is {0x7F,0x00,0x00,0x01}), port is * the port to listen on (host byte order), and the return value is the * file-descriptor or -1 on error. */ int ip_create_listener_split(const unsigned char *ip, unsigned short port); /* Same semantics as above. */ int ip_create_connection_split(const unsigned char *ip, unsigned short port); /* Converts a string into the ip/port before calling the above */ int ip_create_listener(const char *address); int ip_create_connection(const char *address); /* Just does a string conversion on its own. NB: If accept_all_ip is non-zero, * then the address string could be just a port. Ie. it's suitable for a * listening address but not a connecting address. */ int ip_parse_address(const char *address, unsigned char **parsed_ip, unsigned short *port, int accept_all_ip); /* Accepts an incoming connection through the listener. Assumes selects and * what-not have deemed it an appropriate thing to do. */ int ip_accept_connection(int listen_fd); #endif /* !defined(NO_IP) */ #endif /* !defined(_TUNALA_H) */