| SSL_read.pod (72613) | SSL_read.pod (76866) |
|---|---|
| 1=pod 2 3=head1 NAME 4 5SSL_read - read bytes from a TLS/SSL connection. 6 7=head1 SYNOPSIS 8 9 #include <openssl/ssl.h> 10 | 1=pod 2 3=head1 NAME 4 5SSL_read - read bytes from a TLS/SSL connection. 6 7=head1 SYNOPSIS 8 9 #include <openssl/ssl.h> 10 |
| 11 int SSL_read(SSL *ssl, char *buf, int num); | 11 int SSL_read(SSL *ssl, void *buf, int num); |
| 12 13=head1 DESCRIPTION 14 15SSL_read() tries to read B<num> bytes from the specified B<ssl> into the 16buffer B<buf>. 17 18=head1 NOTES 19 20If necessary, SSL_read() will negotiate a TLS/SSL session, if | 12 13=head1 DESCRIPTION 14 15SSL_read() tries to read B<num> bytes from the specified B<ssl> into the 16buffer B<buf>. 17 18=head1 NOTES 19 20If necessary, SSL_read() will negotiate a TLS/SSL session, if |
| 21not already explicitly performed by SSL_connect() or SSL_accept(). If the | 21not already explicitly performed by L<SSL_connect(3)|SSL_connect(3)> or 22L<SSL_accept(3)|SSL_accept(3)>. If the |
| 22peer requests a re-negotiation, it will be performed transparently during 23the SSL_read() operation. The behaviour of SSL_read() depends on the 24underlying BIO. 25 | 23peer requests a re-negotiation, it will be performed transparently during 24the SSL_read() operation. The behaviour of SSL_read() depends on the 25underlying BIO. 26 |
| 27For the transparent negotiation to succeed, the B<ssl> must have been 28initialized to client or server mode. This is not the case if a generic 29method is being used (see L<SSL_CTX_new(3)|SSL_CTX_new(3)>, so that 30L<SSL_set_connect_state(3)|SSL_set_connect_state(3)> or SSL_set_accept_state() 31must be used before the first call to an SSL_read() or 32L<SSL_write(3)|SSL_write(3)> function. 33 |
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| 26If the underlying BIO is B<blocking>, SSL_read() will only return, once the | 34If the underlying BIO is B<blocking>, SSL_read() will only return, once the |
| 27read operation has been finished or an error occurred. | 35read operation has been finished or an error occurred, except when a 36renegotiation take place, in which case a SSL_ERROR_WANT_READ may occur. 37This behaviour can be controlled with the SSL_MODE_AUTO_RETRY flag of the 38L<SSL_CTX_set_mode(3)|SSL_CTX_set_mode(3)> call. |
| 28 29If the underlying BIO is B<non-blocking>, SSL_read() will also return 30when the underlying BIO could not satisfy the needs of SSL_read() | 39 40If the underlying BIO is B<non-blocking>, SSL_read() will also return 41when the underlying BIO could not satisfy the needs of SSL_read() |
| 31to continue the operation. In this case a call to SSL_get_error() with the | 42to continue the operation. In this case a call to 43L<SSL_get_error(3)|SSL_get_error(3)> with the |
| 32return value of SSL_read() will yield B<SSL_ERROR_WANT_READ> or 33B<SSL_ERROR_WANT_WRITE>. As at any time a re-negotiation is possible, a 34call to SSL_read() can also cause write operations! The calling process 35then must repeat the call after taking appropriate action to satisfy the 36needs of SSL_read(). The action depends on the underlying BIO. When using a 37non-blocking socket, nothing is to be done, but select() can be used to check 38for the required condition. When using a buffering BIO, like a BIO pair, data 39must be written into or retrieved out of the BIO before being able to continue. --- 27 unchanged lines hidden (view full) --- 67or action must be taken by the calling process. Call SSL_get_error() with the 68return value B<ret> to find out the reason. 69 70=back 71 72=head1 SEE ALSO 73 74L<SSL_get_error(3)|SSL_get_error(3)>, L<SSL_write(3)|SSL_write(3)>, | 44return value of SSL_read() will yield B<SSL_ERROR_WANT_READ> or 45B<SSL_ERROR_WANT_WRITE>. As at any time a re-negotiation is possible, a 46call to SSL_read() can also cause write operations! The calling process 47then must repeat the call after taking appropriate action to satisfy the 48needs of SSL_read(). The action depends on the underlying BIO. When using a 49non-blocking socket, nothing is to be done, but select() can be used to check 50for the required condition. When using a buffering BIO, like a BIO pair, data 51must be written into or retrieved out of the BIO before being able to continue. --- 27 unchanged lines hidden (view full) --- 79or action must be taken by the calling process. Call SSL_get_error() with the 80return value B<ret> to find out the reason. 81 82=back 83 84=head1 SEE ALSO 85 86L<SSL_get_error(3)|SSL_get_error(3)>, L<SSL_write(3)|SSL_write(3)>, |
| 87L<SSL_CTX_set_mode(3)|SSL_CTX_set_mode(3)>, L<SSL_CTX_new(3)|SSL_CTX_new(3)>, 88L<SSL_connect(3)|SSL_connect(3)>, L<SSL_accept(3)|SSL_accept(3)> 89L<SSL_set_connect_state(3)|SSL_set_connect_state(3)>, |
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| 75L<ssl(3)|ssl(3)>, L<bio(3)|bio(3)> 76 77=cut | 90L<ssl(3)|ssl(3)>, L<bio(3)|bio(3)> 91 92=cut |