New SSL API mode 'SSL_MODE_AUTO_RETRY', which disables the default

behaviour that SSL_read may result in SSL_ERROR_WANT_READ.

CHANGES

@@ -4,6 +4,15 @@
 
  Changes between 0.9.5a and 0.9.6  [xx XXX 2000]
 
+  *) New SSL API mode 'SSL_MODE_AUTO_RETRY'.  This disables the default
+     behaviour that SSL_read may result in SSL_ERROR_WANT_READ (even if
+     the underlying transport is blocking) if a handshake took place.
+     (The default behaviour is needed by applications such as s_client
+     and s_server that use select() to determine when to use SSL_read;
+     but for applications that know in advance when to expect data, it
+     just makes things more complicated.)
+     [Bodo Moeller]
+
   *) Add RAND_egd_bytes(), which gives control over the number of bytes read
      from EGD.
      [Ben Laurie]

ssl/s3_pkt.c

@@ -899,19 +899,21 @@ start:
 					return(-1);
 					}
 
-				if (s->s3->rbuf.left == 0) /* no read-ahead left? */
+				if (!(s->mode & SSL_MODE_AUTO_RETRY))
 					{
-					BIO *bio;
-					/* In the case where we try to read application data
-					 * the first time, but we trigger an SSL handshake, we
-					 * return -1 with the retry option set.  I do this
-					 * otherwise renegotiation can cause nasty problems 
-					 * in the blocking world */ /* ? */
-					s->rwstate=SSL_READING;
-					bio=SSL_get_rbio(s);
-					BIO_clear_retry_flags(bio);
-					BIO_set_retry_read(bio);
-					return(-1);
+					if (s->s3->rbuf.left == 0) /* no read-ahead left? */
+						{
+						BIO *bio;
+						/* In the case where we try to read application data,
+						 * but we trigger an SSL handshake, we return -1 with
+						 * the retry option set.  Otherwise renegotiation may
+						 * cause nasty problems in the blocking world */
+						s->rwstate=SSL_READING;
+						bio=SSL_get_rbio(s);
+						BIO_clear_retry_flags(bio);
+						BIO_set_retry_read(bio);
+						return(-1);
+						}
 					}
 				}
 			}
@@ -1022,19 +1024,21 @@ start:
 			return(-1);
 			}
 
-		if (s->s3->rbuf.left == 0) /* no read-ahead left? */
+		if (!(s->mode & SSL_MODE_AUTO_RETRY))
 			{
-			BIO *bio;
-			/* In the case where we try to read application data
-			 * the first time, but we trigger an SSL handshake, we
-			 * return -1 with the retry option set.  I do this
-			 * otherwise renegotiation can cause nasty problems 
-			 * in the blocking world */ /* ? */
-			s->rwstate=SSL_READING;
-			bio=SSL_get_rbio(s);
-			BIO_clear_retry_flags(bio);
-			BIO_set_retry_read(bio);
-			return(-1);
+			if (s->s3->rbuf.left == 0) /* no read-ahead left? */
+				{
+				BIO *bio;
+				/* In the case where we try to read application data,
+				 * but we trigger an SSL handshake, we return -1 with
+				 * the retry option set.  Otherwise renegotiation may
+				 * cause nasty problems in the blocking world */
+				s->rwstate=SSL_READING;
+				bio=SSL_get_rbio(s);
+				BIO_clear_retry_flags(bio);
+				BIO_set_retry_read(bio);
+				return(-1);
+				}
 			}
 		goto start;
 		}

ssl/ssl.h

@@ -335,6 +335,9 @@ typedef struct ssl_session_st
  * the misconception that non-blocking SSL_write() behaves like
  * non-blocking write(): */
 #define SSL_MODE_ACCEPT_MOVING_WRITE_BUFFER 0x00000002L
+/* Never bother the application with retries if the transport
+ * is blocking: */
+#define SSL_MODE_AUTO_RETRY 0x00000004L
 
 /* Note: SSL[_CTX]_set_{options,mode} use |= op on the previous value,
  * they cannot be used to clear bits. */