Name

SSL_CTX_set_mode, SSL_set_mode
SSL_CTX_get_mode, SSL_get_mode

manipulate SSL engine mode

Library

libssl.lib

#include <openssl/ssl.h>

long SSL_CTX_set_mode(SSL_CTX *ctx, long mode);
long SSL_set_mode(SSL *ssl, long mode);

long SSL_CTX_get_mode(SSL_CTX *ctx);
long SSL_get_mode(SSL *ssl);

SSL_CTX_set_mode() adds the mode set via bitmask in mode to ctx. Options already set before are not cleared.

SSL_set_mode() adds the mode set via bitmask in mode to ssl. Options already set before are not cleared.

SSL_CTX_get_mode() returns the mode set for ctx.

SSL_get_mode() returns the mode set for ssl.

The following mode changes are available:

SSL_MODE_ENABLE_PARTIAL_WRITE: Allow SSL_write(..., n) to return r with 0 < r < n (i.e. report success when just a single record has been written). When not set (the default), SSL_write() will only report success once the complete chunk was written. Once SSL_write() returns with r, r bytes have been successfully written and the next call to SSL_write() must only send the n-r bytes left, imitating the behaviour of write().

SSL_MODE_ACCEPT_MOVING_WRITE_BUFFER: Make it possible to retry SSL_write() with changed buffer location (the buffer contents must stay the same). This is not the default to avoid the misconception that non-blocking SSL_write() behaves like non-blocking write().

SSL_MODE_AUTO_RETRY: Never bother the application with retries if the transport is blocking. If a renegotiation take place during normal operation, a SSL_read() or SSL_write() would return with -1 and indicate the need to retry with SSL_ERROR_WANT_READ. In a non-blocking environment applications must be prepared to handle incomplete read/write operations. In a blocking environment, applications are not always prepared to deal with read/write operations returning without success report. The flag SSL_MODE_AUTO_RETRY will cause read/write operations to only return after the handshake and successful completion.

SSL_CTX_set_mode() and SSL_set_mode() return the new mode bitmask after adding mode.

SSL_CTX_get_mode() and SSL_get_mode() return the current bitmask.

SSL_MODE_AUTO_RETRY as been added in OpenSSL 0.9.6.

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