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Subject: [PATCH] use snprintf in knownhost_writeline() rather then sprintf

[PATCH] use snprintf in knownhost_writeline() rather then sprintf

From: Steven Dake <sdake_at_redhat.com>
Date: Tue, 6 Mar 2012 00:09:42 -0700

Although the function checks the length, if the code was in error, there
could potentially be a buffer overrun with the use of sprintf. Instead replace
with snprintf.

Signed-off-by: Steven Dake <sdake_at_redhat.com>

---
 src/knownhost.c |    8 ++++----
 1 files changed, 4 insertions(+), 4 deletions(-)
diff --git a/src/knownhost.c b/src/knownhost.c
index 193bda3..c58dfbb 100644
--- a/src/knownhost.c
+++ b/src/knownhost.c
@@ -997,10 +997,10 @@ knownhost_writeline(LIBSSH2_KNOWNHOSTS *hosts,
 
         if(nlen <= buflen)
             if(node->comment)
-                sprintf(buf, "|1|%s|%s%s %s %s\n", saltalloc, namealloc,
+                snprintf(buf, buflen, "|1|%s|%s%s %s %s\n", saltalloc, namealloc,
                         keytype, node->key, node->comment);
             else
-                sprintf(buf, "|1|%s|%s%s %s\n", saltalloc, namealloc,
+                snprintf(buf, buflen, "|1|%s|%s%s %s\n", saltalloc, namealloc,
                         keytype, node->key);
         else
             rc = _libssh2_error(hosts->session, LIBSSH2_ERROR_BUFFER_TOO_SMALL,
@@ -1016,10 +1016,10 @@ knownhost_writeline(LIBSSH2_KNOWNHOSTS *hosts,
         if(nlen <= buflen)
             /* these types have the plain name */
             if(node->comment)
-                sprintf(buf, "%s%s %s %s\n", node->name, keytype, node->key,
+                snprintf(buf, buflen, "%s%s %s %s\n", node->name, keytype, node->key,
                         node->comment);
             else
-                sprintf(buf, "%s%s %s\n", node->name, keytype, node->key);
+                snprintf(buf, buflen, "%s%s %s\n", node->name, keytype, node->key);
         else
             rc = _libssh2_error(hosts->session, LIBSSH2_ERROR_BUFFER_TOO_SMALL,
                                 "Known-host write buffer too small");
-- 
1.7.7.6
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Received on 2012-03-06

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