Hi Scott and Viktor, After some time spent debugging and trying to figure out the ssl::stream code, I think have found the problem (actually there were two): - A read operation should check the read buffer first to see if there's any data present and use that first, before issuing a new read from the socket. - The read buffer is a member of the openssl_operation class, and a new openssl_operation object is created for each read or write initiated by the application. This means that any surplus data from a previous read is lost. Can you please try the diffs included below and let me know how it goes. Thanks! Cheers, Chris Index: asio/ssl/detail/openssl_operation.hpp =================================================================== RCS file: /cvsroot/asio/asio/include/asio/ssl/detail/openssl_operation.hpp,v retrieving revision 1.9 diff -u -r1.9 openssl_operation.hpp --- asio/ssl/detail/openssl_operation.hpp 28 May 2006 06:54:42 -0000 1.9 +++ asio/ssl/detail/openssl_operation.hpp 21 Jul 2006 05:31:07 -0000 @@ -82,12 +82,14 @@ // Constructor for asynchronous operations openssl_operation(ssl_primitive_func primitive, Stream& socket, + net_buffer& recv_buf, SSL* session, BIO* ssl_bio, user_handler_func handler ) : primitive_(primitive) , user_handler_(handler) + , recv_buf_(recv_buf) , socket_(socket) , ssl_bio_(ssl_bio) , session_(session) @@ -105,9 +107,11 @@ // Constructor for synchronous operations openssl_operation(ssl_primitive_func primitive, Stream& socket, + net_buffer& recv_buf, SSL* session, BIO* ssl_bio) : primitive_(primitive) + , recv_buf_(recv_buf) , socket_(socket) , ssl_bio_(ssl_bio) , session_(session) @@ -165,6 +169,36 @@ // not want network communication nor does want to send shutdown out... return handler_(asio::error(error_code), rc); + if (!is_operation_done && !is_write_needed) + { + // We may have left over data that we can pass to SSL immediately + if (recv_buf_.get_data_len() > 0) + { + // Pass the buffered data to SSL + int written = ::BIO_write + ( + ssl_bio_, + recv_buf_.get_data_start(), + recv_buf_.get_data_len() + ); + + if (written > 0) + { + recv_buf_.data_removed(written); + } + else if (written < 0) + { + if (!BIO_should_retry(ssl_bio_)) + { + // Some serios error with BIO.... + return handler_(asio::error(asio::error::no_recovery), 0); + } + } + + return start(); + } + } + // Continue with operation, flush any SSL data out to network... return write_(is_operation_done, rc); } @@ -181,7 +215,12 @@ int_handler_func handler_; net_buffer send_buf_; // buffers for network IO - net_buffer recv_buf_; + + // The recv buffer is owned by the stream, not the operation, since there can + // be left over bytes after passing the data up to the application, and these + // bytes need to be kept around for the next read operation issued by the + // application. + net_buffer& recv_buf_; Stream& socket_; BIO* ssl_bio_; Index: asio/ssl/detail/openssl_stream_service.hpp =================================================================== RCS file: /cvsroot/asio/asio/include/asio/ssl/detail/openssl_stream_service.hpp,v retrieving revision 1.11 diff -u -r1.11 openssl_stream_service.hpp --- asio/ssl/detail/openssl_stream_service.hpp 16 Jun 2006 11:52:28 -0000 1.11 +++ asio/ssl/detail/openssl_stream_service.hpp 21 Jul 2006 05:41:34 -0000 @@ -152,6 +152,7 @@ { ::SSL* ssl; ::BIO* ext_bio; + net_buffer recv_buf; } * impl_type; // Construct a new stream socket service for the specified io_service. @@ -179,6 +180,7 @@ impl = new impl_struct; impl->ssl = ::SSL_new(context.impl()); ::SSL_set_mode(impl->ssl, SSL_MODE_ENABLE_PARTIAL_WRITE); + ::SSL_set_mode(impl->ssl, SSL_MODE_ACCEPT_MOVING_WRITE_BUFFER); ::BIO* int_bio = 0; impl->ext_bio = 0; ::BIO_new_bio_pair(&int_bio, 8192, &impl->ext_bio, 8192); @@ -240,6 +242,7 @@ &ssl_wrap<mutex_type>::SSL_connect: &ssl_wrap<mutex_type>::SSL_accept, next_layer, + impl->recv_buf, impl->ssl, impl->ext_bio, boost::bind @@ -265,6 +268,7 @@ openssl_operation<Stream> op( &ssl_wrap<mutex_type>::SSL_shutdown, next_layer, + impl->recv_buf, impl->ssl, impl->ext_bio); op.start(); @@ -292,6 +296,7 @@ ( &ssl_wrap<mutex_type>::SSL_shutdown, next_layer, + impl->recv_buf, impl->ssl, impl->ext_bio, boost::bind @@ -322,6 +327,7 @@ openssl_operation<Stream> op( send_func, next_layer, + impl->recv_buf, impl->ssl, impl->ext_bio ); @@ -356,6 +362,7 @@ ( send_func, next_layer, + impl->recv_buf, impl->ssl, impl->ext_bio, boost::bind @@ -385,6 +392,7 @@ asio::buffer_size(*buffers.begin())); openssl_operation<Stream> op(recv_func, next_layer, + impl->recv_buf, impl->ssl, impl->ext_bio ); @@ -420,6 +428,7 @@ ( recv_func, next_layer, + impl->recv_buf, impl->ssl, impl->ext_bio, boost::bind