From: Todd C. Miller <Todd.Miller@courtesan.com>
Date: Mon, 1 Nov 1999 15:58:46 +0000 (+0000)
Subject: When read()'ing, do a single character at a time to be sure we don't go
X-Git-Tag: SUDO_1_6_0~22
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=68fd7e74c12f94080e54699ce0f16639f4f3a3ab;p=sudo

When read()'ing, do a single character at a time to be sure we don't go
oast the newline.
---

diff --git a/tgetpass.c b/tgetpass.c
index 213c32ac2..df079888c 100644
--- a/tgetpass.c
+++ b/tgetpass.c
@@ -182,8 +182,12 @@ tgetline(fd, buf, bufsiz, timeout)
     int n;
     fd_set *readfds = NULL;
     struct timeval tv;
+    char c;
     char *cp;
 
+    if (bufsiz == 0)
+	return(NULL);			/* sanity */
+
     /*
      * Timeout of <= 0 means no timeout.
      */
@@ -210,16 +214,12 @@ tgetline(fd, buf, bufsiz, timeout)
     if (readfds)
 	free(readfds);
 
-    /* Get a line of input */
-    left = bufsiz;
+    /* Keep reading until out of space, EOF, error, or newline */
     cp = buf;
-    do {
-	if ((n = read(fd, cp, left)) > 0) {
-	    cp += n;
-	    left -= n;
-	}
-    } while (n > 0 && left != 0 && *(cp - 1) != '\n');
-    *(cp - 1) = '\0';
+    left = bufsiz;
+    while (--left && (n = read(fd, &c, 1)) == 1 && c != '\n')
+	*cp++ = c;
+    *cp = '\0';
 
-    return(left == bufsiz ? NULL : buf);
+    return(cp == buf ? NULL : buf);
 }