Add new filter BIO BIO_f_readbuffer()

This allows BIO_tell() and BIO_seek() to work for BIO's that do
not support these methods. The main use case for this is file/fd BIO's
that use stdin.

This works for stdin taken from input redirection (command < file),
and stdin via pipe (cat file | command).

Reviewed-by: Tomas Mraz <tomas@openssl.org>
Reviewed-by: Matt Caswell <matt@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/14407)

1 files changed, 1 insertions, 0 deletions

diff --git a/include/openssl/bio.h.in b/include/openssl/bio.h.in
index 6bb4876022..3b2f7e98f5 100644
--- a/include/openssl/bio.h.in
+++ b/include/openssl/bio.h.in
@@ -647,6 +647,7 @@ const BIO_METHOD *BIO_s_bio(void);
 const BIO_METHOD *BIO_s_null(void);
 const BIO_METHOD *BIO_f_null(void);
 const BIO_METHOD *BIO_f_buffer(void);
+const BIO_METHOD *BIO_f_readbuffer(void);
 const BIO_METHOD *BIO_f_linebuffer(void);
 const BIO_METHOD *BIO_f_nbio_test(void);
 const BIO_METHOD *BIO_f_prefix(void);