Add macros to compute base64 encode/decode lengths.

clients/tools/ldappasswd.c

@@ -41,8 +41,6 @@
 #include "ldap_defaults.h"
 
 /* local macros */
-#define CEILING(x)	((double)(x) > (int)(x) ? (int)(x) + 1 : (int)(x))
-
 #define LDAP_PASSWD_ATTRIB "userPassword"
 #define LDAP_PASSWD_CONF   LDAP_SYSCONFDIR LDAP_DIRSEP "passwd.conf"
 
@@ -107,8 +105,10 @@ pw_encode (unsigned char *passwd, Salt * salt, unsigned int len)
 		len += salt->len;
 	}
 
-	b64_len = CEILING (len / 3) * 4 + 1;
+	b64_len = LUTIL_BASE64_ENCODE_LEN(len) + 1;
+
 	base64digest = (char *)malloc (b64_len);
+
 	if (lutil_b64_ntop (npasswd, len, base64digest, b64_len) < 0)
 	{
 		free (base64digest);

include/lutil.h

@@ -19,6 +19,12 @@
  * Include file for LDAP utility routine
  */
 
+/* n octets encode into ceiling(n/3) * 4 bytes */
+/* Avoid floating point math by through extra padding */
+
+#define LUTIL_BASE64_ENCODE_LEN(n)	((n)/3 * 4 + 4)
+#define LUTIL_BASE64_DECODE_LEN(n)	((n)/4 * 3)
+
 LDAP_BEGIN_DECL
 
 /* ISC Base64 Routines */

libraries/liblutil/passwd.c

@@ -109,7 +109,7 @@ lutil_passwd(
 	if ((p = passwd_scheme( passwd, "{MD5}", schemes )) != NULL ) {
 		lutil_MD5_CTX MD5context;
 		unsigned char MD5digest[16];
-		char base64digest[25];  /* ceiling(sizeof(input)/3) * 4 + 1 */
+		char base64digest[LUTIL_BASE64_ENCODE_LEN(16)]; 
 
 		lutil_MD5Init(&MD5context);
 		lutil_MD5Update(&MD5context,
@@ -127,7 +127,7 @@ lutil_passwd(
 	} else if ((p = passwd_scheme( passwd, "{SHA}", schemes )) != NULL ) {
 		lutil_SHA1_CTX SHA1context;
 		unsigned char SHA1digest[20];
-		char base64digest[29];  /* ceiling(sizeof(input)/3) * 4 + 1 */
+		char base64digest[LUTIL_BASE64_ENCODE_LEN(20)]; 
 
 		lutil_SHA1Init(&SHA1context);
 		lutil_SHA1Update(&SHA1context,
@@ -150,7 +150,8 @@ lutil_passwd(
 		unsigned char *orig_pass = NULL;
  
 		/* base64 un-encode password */
-		orig_pass = (unsigned char *)malloc((size_t)(pw_len * 0.75 + 1));
+		orig_pass = (unsigned char *) malloc( (size_t) (
+			LUTIL_BASE64_DECODE_LEN(pw_len) + 1) );
 		if ((rc = lutil_b64_pton(p, orig_pass, pw_len)) < 0)
 		{
 			free(orig_pass);
@@ -179,7 +180,8 @@ lutil_passwd(
 		unsigned char *orig_pass = NULL;
 
 		/* base64 un-encode password */
-		orig_pass = (unsigned char *)malloc((size_t)(pw_len * 0.75 + 1));
+		orig_pass = (unsigned char *) malloc( (size_t) (
+			LUTIL_BASE64_DECODE_LEN(pw_len) + 1) );
 		if ((rc = lutil_b64_pton(p, orig_pass, pw_len)) < 0)
 		{
 			free(orig_pass);