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Diffstat (limited to 'doc/crypto/BIO_f_ssl.pod')
-rw-r--r-- | doc/crypto/BIO_f_ssl.pod | 322 |
1 files changed, 0 insertions, 322 deletions
diff --git a/doc/crypto/BIO_f_ssl.pod b/doc/crypto/BIO_f_ssl.pod deleted file mode 100644 index a9f23f1dd7de..000000000000 --- a/doc/crypto/BIO_f_ssl.pod +++ /dev/null @@ -1,322 +0,0 @@ -=pod - -=head1 NAME - -BIO_f_ssl, BIO_set_ssl, BIO_get_ssl, BIO_set_ssl_mode, BIO_set_ssl_renegotiate_bytes, -BIO_get_num_renegotiates, BIO_set_ssl_renegotiate_timeout, BIO_new_ssl, -BIO_new_ssl_connect, BIO_new_buffer_ssl_connect, BIO_ssl_copy_session_id, -BIO_ssl_shutdown - SSL BIO - -=head1 SYNOPSIS - - #include <openssl/bio.h> - #include <openssl/ssl.h> - - BIO_METHOD *BIO_f_ssl(void); - - #define BIO_set_ssl(b,ssl,c) BIO_ctrl(b,BIO_C_SET_SSL,c,(char *)ssl) - #define BIO_get_ssl(b,sslp) BIO_ctrl(b,BIO_C_GET_SSL,0,(char *)sslp) - #define BIO_set_ssl_mode(b,client) BIO_ctrl(b,BIO_C_SSL_MODE,client,NULL) - #define BIO_set_ssl_renegotiate_bytes(b,num) \ - BIO_ctrl(b,BIO_C_SET_SSL_RENEGOTIATE_BYTES,num,NULL); - #define BIO_set_ssl_renegotiate_timeout(b,seconds) \ - BIO_ctrl(b,BIO_C_SET_SSL_RENEGOTIATE_TIMEOUT,seconds,NULL); - #define BIO_get_num_renegotiates(b) \ - BIO_ctrl(b,BIO_C_SET_SSL_NUM_RENEGOTIATES,0,NULL); - - BIO *BIO_new_ssl(SSL_CTX *ctx,int client); - BIO *BIO_new_ssl_connect(SSL_CTX *ctx); - BIO *BIO_new_buffer_ssl_connect(SSL_CTX *ctx); - int BIO_ssl_copy_session_id(BIO *to,BIO *from); - void BIO_ssl_shutdown(BIO *bio); - - #define BIO_do_handshake(b) BIO_ctrl(b,BIO_C_DO_STATE_MACHINE,0,NULL) - -=head1 DESCRIPTION - -BIO_f_ssl() returns the SSL BIO method. This is a filter BIO which -is a wrapper round the OpenSSL SSL routines adding a BIO "flavour" to -SSL I/O. - -I/O performed on an SSL BIO communicates using the SSL protocol with -the SSLs read and write BIOs. If an SSL connection is not established -then an attempt is made to establish one on the first I/O call. - -If a BIO is appended to an SSL BIO using BIO_push() it is automatically -used as the SSL BIOs read and write BIOs. - -Calling BIO_reset() on an SSL BIO closes down any current SSL connection -by calling SSL_shutdown(). BIO_reset() is then sent to the next BIO in -the chain: this will typically disconnect the underlying transport. -The SSL BIO is then reset to the initial accept or connect state. - -If the close flag is set when an SSL BIO is freed then the internal -SSL structure is also freed using SSL_free(). - -BIO_set_ssl() sets the internal SSL pointer of BIO B<b> to B<ssl> using -the close flag B<c>. - -BIO_get_ssl() retrieves the SSL pointer of BIO B<b>, it can then be -manipulated using the standard SSL library functions. - -BIO_set_ssl_mode() sets the SSL BIO mode to B<client>. If B<client> -is 1 client mode is set. If B<client> is 0 server mode is set. - -BIO_set_ssl_renegotiate_bytes() sets the renegotiate byte count -to B<num>. When set after every B<num> bytes of I/O (read and write) -the SSL session is automatically renegotiated. B<num> must be at -least 512 bytes. - -BIO_set_ssl_renegotiate_timeout() sets the renegotiate timeout to -B<seconds>. When the renegotiate timeout elapses the session is -automatically renegotiated. - -BIO_get_num_renegotiates() returns the total number of session -renegotiations due to I/O or timeout. - -BIO_new_ssl() allocates an SSL BIO using SSL_CTX B<ctx> and using -client mode if B<client> is non zero. - -BIO_new_ssl_connect() creates a new BIO chain consisting of an -SSL BIO (using B<ctx>) followed by a connect BIO. - -BIO_new_buffer_ssl_connect() creates a new BIO chain consisting -of a buffering BIO, an SSL BIO (using B<ctx>) and a connect -BIO. - -BIO_ssl_copy_session_id() copies an SSL session id between -BIO chains B<from> and B<to>. It does this by locating the -SSL BIOs in each chain and calling SSL_copy_session_id() on -the internal SSL pointer. - -BIO_ssl_shutdown() closes down an SSL connection on BIO -chain B<bio>. It does this by locating the SSL BIO in the -chain and calling SSL_shutdown() on its internal SSL -pointer. - -BIO_do_handshake() attempts to complete an SSL handshake on the -supplied BIO and establish the SSL connection. It returns 1 -if the connection was established successfully. A zero or negative -value is returned if the connection could not be established, the -call BIO_should_retry() should be used for non blocking connect BIOs -to determine if the call should be retried. If an SSL connection has -already been established this call has no effect. - -=head1 NOTES - -SSL BIOs are exceptional in that if the underlying transport -is non blocking they can still request a retry in exceptional -circumstances. Specifically this will happen if a session -renegotiation takes place during a BIO_read() operation, one -case where this happens is when step up occurs. - -In OpenSSL 0.9.6 and later the SSL flag SSL_AUTO_RETRY can be -set to disable this behaviour. That is when this flag is set -an SSL BIO using a blocking transport will never request a -retry. - -Since unknown BIO_ctrl() operations are sent through filter -BIOs the servers name and port can be set using BIO_set_host() -on the BIO returned by BIO_new_ssl_connect() without having -to locate the connect BIO first. - -Applications do not have to call BIO_do_handshake() but may wish -to do so to separate the handshake process from other I/O -processing. - -=head1 RETURN VALUES - -TBA - -=head1 EXAMPLE - -This SSL/TLS client example, attempts to retrieve a page from an -SSL/TLS web server. The I/O routines are identical to those of the -unencrypted example in L<BIO_s_connect(3)|BIO_s_connect(3)>. - - BIO *sbio, *out; - int len; - char tmpbuf[1024]; - SSL_CTX *ctx; - SSL *ssl; - - ERR_load_crypto_strings(); - ERR_load_SSL_strings(); - OpenSSL_add_all_algorithms(); - - /* We would seed the PRNG here if the platform didn't - * do it automatically - */ - - ctx = SSL_CTX_new(SSLv23_client_method()); - - /* We'd normally set some stuff like the verify paths and - * mode here because as things stand this will connect to - * any server whose certificate is signed by any CA. - */ - - sbio = BIO_new_ssl_connect(ctx); - - BIO_get_ssl(sbio, &ssl); - - if(!ssl) { - fprintf(stderr, "Can't locate SSL pointer\n"); - /* whatever ... */ - } - - /* Don't want any retries */ - SSL_set_mode(ssl, SSL_MODE_AUTO_RETRY); - - /* We might want to do other things with ssl here */ - - BIO_set_conn_hostname(sbio, "localhost:https"); - - out = BIO_new_fp(stdout, BIO_NOCLOSE); - if(BIO_do_connect(sbio) <= 0) { - fprintf(stderr, "Error connecting to server\n"); - ERR_print_errors_fp(stderr); - /* whatever ... */ - } - - if(BIO_do_handshake(sbio) <= 0) { - fprintf(stderr, "Error establishing SSL connection\n"); - ERR_print_errors_fp(stderr); - /* whatever ... */ - } - - /* Could examine ssl here to get connection info */ - - BIO_puts(sbio, "GET / HTTP/1.0\n\n"); - for(;;) { - len = BIO_read(sbio, tmpbuf, 1024); - if(len <= 0) break; - BIO_write(out, tmpbuf, len); - } - BIO_free_all(sbio); - BIO_free(out); - -Here is a simple server example. It makes use of a buffering -BIO to allow lines to be read from the SSL BIO using BIO_gets. -It creates a pseudo web page containing the actual request from -a client and also echoes the request to standard output. - - BIO *sbio, *bbio, *acpt, *out; - int len; - char tmpbuf[1024]; - SSL_CTX *ctx; - SSL *ssl; - - ERR_load_crypto_strings(); - ERR_load_SSL_strings(); - OpenSSL_add_all_algorithms(); - - /* Might seed PRNG here */ - - ctx = SSL_CTX_new(SSLv23_server_method()); - - if (!SSL_CTX_use_certificate_file(ctx,"server.pem",SSL_FILETYPE_PEM) - || !SSL_CTX_use_PrivateKey_file(ctx,"server.pem",SSL_FILETYPE_PEM) - || !SSL_CTX_check_private_key(ctx)) { - - fprintf(stderr, "Error setting up SSL_CTX\n"); - ERR_print_errors_fp(stderr); - return 0; - } - - /* Might do other things here like setting verify locations and - * DH and/or RSA temporary key callbacks - */ - - /* New SSL BIO setup as server */ - sbio=BIO_new_ssl(ctx,0); - - BIO_get_ssl(sbio, &ssl); - - if(!ssl) { - fprintf(stderr, "Can't locate SSL pointer\n"); - /* whatever ... */ - } - - /* Don't want any retries */ - SSL_set_mode(ssl, SSL_MODE_AUTO_RETRY); - - /* Create the buffering BIO */ - - bbio = BIO_new(BIO_f_buffer()); - - /* Add to chain */ - sbio = BIO_push(bbio, sbio); - - acpt=BIO_new_accept("4433"); - - /* By doing this when a new connection is established - * we automatically have sbio inserted into it. The - * BIO chain is now 'swallowed' by the accept BIO and - * will be freed when the accept BIO is freed. - */ - - BIO_set_accept_bios(acpt,sbio); - - out = BIO_new_fp(stdout, BIO_NOCLOSE); - - /* Setup accept BIO */ - if(BIO_do_accept(acpt) <= 0) { - fprintf(stderr, "Error setting up accept BIO\n"); - ERR_print_errors_fp(stderr); - return 0; - } - - /* Now wait for incoming connection */ - if(BIO_do_accept(acpt) <= 0) { - fprintf(stderr, "Error in connection\n"); - ERR_print_errors_fp(stderr); - return 0; - } - - /* We only want one connection so remove and free - * accept BIO - */ - - sbio = BIO_pop(acpt); - - BIO_free_all(acpt); - - if(BIO_do_handshake(sbio) <= 0) { - fprintf(stderr, "Error in SSL handshake\n"); - ERR_print_errors_fp(stderr); - return 0; - } - - BIO_puts(sbio, "HTTP/1.0 200 OK\r\nContent-type: text/plain\r\n\r\n"); - BIO_puts(sbio, "\r\nConnection Established\r\nRequest headers:\r\n"); - BIO_puts(sbio, "--------------------------------------------------\r\n"); - - for(;;) { - len = BIO_gets(sbio, tmpbuf, 1024); - if(len <= 0) break; - BIO_write(sbio, tmpbuf, len); - BIO_write(out, tmpbuf, len); - /* Look for blank line signifying end of headers*/ - if((tmpbuf[0] == '\r') || (tmpbuf[0] == '\n')) break; - } - - BIO_puts(sbio, "--------------------------------------------------\r\n"); - BIO_puts(sbio, "\r\n"); - - /* Since there is a buffering BIO present we had better flush it */ - BIO_flush(sbio); - - BIO_free_all(sbio); - -=head1 BUGS - -In OpenSSL versions before 1.0.0 the BIO_pop() call was handled incorrectly, -the I/O BIO reference count was incorrectly incremented (instead of -decremented) and dissociated with the SSL BIO even if the SSL BIO was not -explicitly being popped (e.g. a pop higher up the chain). Applications which -included workarounds for this bug (e.g. freeing BIOs more than once) should -be modified to handle this fix or they may free up an already freed BIO. - -=head1 SEE ALSO - -TBA |