NetBSD Problem Report #50907

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Message-Id: <20160307120819.9ED4B7ACBA@mollari.NetBSD.org>
Date: Mon,  7 Mar 2016 12:08:19 +0000 (UTC)
From: dcb314@hotmail.com
Reply-To: dcb314@hotmail.com
To: gnats-bugs@NetBSD.org
Subject: src/lib/libresolv/hmac_link.c: clumsy call to memset ?
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>Number:         50907
>Category:       lib
>Synopsis:       src/lib/libresolv/hmac_link.c: clumsy call to memset ?
>Confidential:   no
>Severity:       non-critical
>Priority:       low
>Responsible:    lib-bug-people
>State:          closed
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Mon Mar 07 12:10:00 +0000 2016
>Closed-Date:    Mon Mar 07 14:39:18 +0000 2016
>Last-Modified:  Mon Mar 07 14:40:00 +0000 2016
>Originator:     David Binderman
>Release:        cvs dated 20160305
>Organization:
>Environment:
>Description:
[src/lib/libresolv/hmac_link.c:285] -> [src/lib/libresolv/hmac_link.c:287]: (performance) Buffer 'buff' is being written before its old content has been used.

Source code is

    memset(buff, 0, buff_len);  /*%< just in case */
    /* write file header */
    snprintf(buff, buff_len, KEY_FILE_FMT_STR, KEY_FILE_FORMAT,
        KEY_HMAC_MD5, "HMAC");

    bp = buff + strlen(buff);

Maybe better code

    /* write file header */
    snprintf(buff, buff_len, KEY_FILE_FMT_STR, KEY_FILE_FORMAT,
        KEY_HMAC_MD5, "HMAC");

    bp = buff + strlen(buff);
    memset(bp, 0, buff_len - (bp - buff));  /*%< just in case */

>How-To-Repeat:

>Fix:

>Release-Note:

>Audit-Trail:

State-Changed-From-To: open->closed
State-Changed-By: wiz@NetBSD.org
State-Changed-When: Mon, 07 Mar 2016 14:39:18 +0000
State-Changed-Why:
Fixed by christos, thanks.


From: "Christos Zoulas" <christos@netbsd.org>
To: gnats-bugs@gnats.NetBSD.org
Cc: 
Subject: PR/50907 CVS commit: src/lib/libresolv
Date: Mon, 7 Mar 2016 09:35:39 -0500

 Module Name:	src
 Committed By:	christos
 Date:		Mon Mar  7 14:35:39 UTC 2016

 Modified Files:
 	src/lib/libresolv: hmac_link.c

 Log Message:
 PR/50907: David Binderman: Remove useless strlen()'s and memcpy()'s.


 To generate a diff of this commit:
 cvs rdiff -u -r1.2 -r1.3 src/lib/libresolv/hmac_link.c

 Please note that diffs are not public domain; they are subject to the
 copyright notices on the relevant files.

>Unformatted:

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