Mostly align BIO_read()/BIO_write() return values with OpenSSL 3.x.

For various historical reasons, there are a number of cases where our
BIO_read() and BIO_write() return slightly different values to what
OpenSSL 3.x does (of course OpenSSL 1.0 differs from OpenSSL 1.1 which
differs from OpenSSL 3.x). Mostly align these - some further work will be
needed.

Issue raised by tb@ who also wrote some test code.

diff --git a/lib/libcrypto/bio/bio_lib.c b/lib/libcrypto/bio/bio_lib.c
index 92c0d5e..b33ebe1 100644 (file)
--- a/lib/libcrypto/bio/bio_lib.c
+++ b/lib/libcrypto/bio/bio_lib.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: bio_lib.c,v 1.37 2022/11/28 07:50:00 tb Exp $ */
+/* $OpenBSD: bio_lib.c,v 1.38 2022/11/30 01:56:18 jsing Exp $ */
 /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
  * All rights reserved.
  *
@@ -322,12 +322,19 @@ BIO_read(BIO *b, void *out, int outl)
        size_t readbytes = 0;
        int ret;
 
-       if (b == NULL)
-               return (0);
+       if (b == NULL) {
+               BIOerror(ERR_R_PASSED_NULL_PARAMETER);
+               return (-1);
+       }
 
-       if (out == NULL || outl <= 0)
+       if (outl <= 0)
                return (0);
 
+       if (out == NULL) {
+               BIOerror(ERR_R_PASSED_NULL_PARAMETER);
+               return (-1);
+       }
+
        if (b->method == NULL || b->method->bread == NULL) {
                BIOerror(BIO_R_UNSUPPORTED_METHOD);
                return (-2);
@@ -372,12 +379,19 @@ BIO_write(BIO *b, const void *in, int inl)
        size_t writebytes = 0;
        int ret;
 
-       if (b == NULL)
-               return (0);
+       if (b == NULL) {
+               BIOerror(ERR_R_PASSED_NULL_PARAMETER);
+               return (-1);
+       }
 
-       if (in == NULL || inl <= 0)
+       if (inl <= 0)
                return (0);
 
+       if (in == NULL) {
+               BIOerror(ERR_R_PASSED_NULL_PARAMETER);
+               return (-1);
+       }
+
        if (b->method == NULL || b->method->bwrite == NULL) {
                BIOerror(BIO_R_UNSUPPORTED_METHOD);
                return (-2);