From 416a5b6c92f9f7a664c34a96e63f50c38b7e3291 Mon Sep 17 00:00:00 2001
From: Matt Caswell <matt@openssl.org>
Date: Fri, 3 Jun 2016 15:53:54 +0100
Subject: [PATCH] BIO_printf() can fail to print the last character
If the string to print is exactly 2048 character long (excluding the NULL
terminator) then BIO_printf will chop off the last byte. This is because
it has filled its static buffer but hasn't yet allocated a dynamic buffer.
In cases where we don't have a dynamic buffer we need to truncate but that
is not the case for BIO_printf(). We need to check whether we are able to
have a dynamic buffer buffer deciding to truncate.
Reviewed-by: Rich Salz <rsalz@openssl.org>
---
crypto/bio/b_print.c | 12 +++++++++---
1 file changed, 9 insertions(+), 3 deletions(-)
diff --git a/crypto/bio/b_print.c b/crypto/bio/b_print.c
index 1b70bac71b..6808cdc6de 100644
--- a/crypto/bio/b_print.c
+++ b/crypto/bio/b_print.c
@@ -363,9 +363,15 @@ _dopr(char **sbuffer,
break;
}
}
- *truncated = (currlen > *maxlen - 1);
- if (*truncated)
- currlen = *maxlen - 1;
+ /*
+ * We have to truncate if there is no dynamic buffer and we have filled the
+ * static buffer.
+ */
+ if (buffer == NULL) {
+ *truncated = (currlen > *maxlen - 1);
+ if (*truncated)
+ currlen = *maxlen - 1;
+ }
if(!doapr_outch(sbuffer, buffer, &currlen, maxlen, '\0'))
return 0;
*retlen = currlen - 1;
--
2.25.1