Index: include/base64.h
===================================================================
--- /dev/null
+++ include/base64.h
@@ -0,0 +1,9 @@
+#include <sys/types.h>
+
+#define b64_ntop		__b64_ntop
+#define b64_pton		__b64_pton
+
+int		b64_ntop(unsigned char const *, size_t, char *, size_t);
+int		b64_pton(char const *, unsigned char *, size_t);
+
+int		b64_pton_partial(char const *, unsigned char **, size_t);
Index: include/resolv.h
===================================================================
--- include/resolv.h
+++ include/resolv.h
@@ -59,6 +59,7 @@
 #include <sys/types.h>
 #include <sys/cdefs.h>
 #include <sys/socket.h>
+#include <base64.h>
 #include <stdio.h>
 #include <arpa/nameser.h>
 
@@ -335,8 +336,6 @@
 extern const struct res_sym __p_rcode_syms[];
 #endif /* SHARED_LIBBIND */
 
-#define b64_ntop		__b64_ntop
-#define b64_pton		__b64_pton
 #define dn_comp			__dn_comp
 #define dn_count_labels		__dn_count_labels
 #define dn_expand		__dn_expand
@@ -420,8 +419,6 @@
 int		sym_ston(const struct res_sym *, const char *, int *);
 const char *	sym_ntos(const struct res_sym *, int, int *);
 const char *	sym_ntop(const struct res_sym *, int, int *);
-int		b64_ntop(u_char const *, size_t, char *, size_t);
-int		b64_pton(char const *, u_char *, size_t);
 int		loc_aton(const char *, u_char *);
 const char *	loc_ntoa(const u_char *, char *);
 int		dn_skipname(const u_char *, const u_char *);
Index: lib/libc/net/Symbol.map
===================================================================
--- lib/libc/net/Symbol.map
+++ lib/libc/net/Symbol.map
@@ -5,6 +5,7 @@
 FBSD_1.0 {
 	__b64_ntop;
 	__b64_pton;
+	b64_pton_partial;
 	ether_line;
 	ether_aton;
 	ether_aton_r;
Index: lib/libc/net/base64.c
===================================================================
--- lib/libc/net/base64.c
+++ lib/libc/net/base64.c
@@ -43,15 +43,8 @@
 #include <sys/cdefs.h>
 __FBSDID("$FreeBSD$");
 
-#include <sys/param.h>
-#include <sys/socket.h>
-
-#include <netinet/in.h>
-#include <arpa/inet.h>
-#include <arpa/nameser.h>
-
 #include <ctype.h>
-#include <resolv.h>
+#include <base64.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
@@ -192,14 +185,18 @@
  */
 
 int
-b64_pton(const char *src, u_char *target, size_t targsize)
+b64_pton_partial(const char *src, unsigned char **target, size_t targsize)
 {
-	int tarindex, state, ch;
+	int state, ch;
 	u_char nextbyte;
 	char *pos;
+	unsigned char *tarend, *orig;
 
 	state = 0;
-	tarindex = 0;
+	if (*target) {
+		tarend = *target + targsize;
+		orig = *target;
+	}
 
 	while ((ch = *src++) != '\0') {
 		if (isspace((unsigned char)ch))        /* Skip whitespace anywhere. */
@@ -214,48 +211,48 @@
 
 		switch (state) {
 		case 0:
-			if (target) {
-				if ((size_t)tarindex >= targsize)
+			if (*target) {
+				if (*target >= tarend)
 					return (-1);
-				target[tarindex] = (pos - Base64) << 2;
+				**target = (pos - Base64) << 2;
 			}
 			state = 1;
 			break;
 		case 1:
-			if (target) {
-				if ((size_t)tarindex >= targsize)
+			if (*target) {
+				if (*target >= tarend)
 					return (-1);
-				target[tarindex]   |=  (pos - Base64) >> 4;
+				**target   |=  (pos - Base64) >> 4;
 				nextbyte = ((pos - Base64) & 0x0f) << 4;
-				if ((size_t)tarindex + 1 < targsize)
-					target[tarindex + 1] = nextbyte;
+				if (*target + 1 < tarend)
+					(*target)[1] = nextbyte;
 				else if (nextbyte)
 					return (-1);
 			}
-			tarindex++;
+			(*target)++;
 			state = 2;
 			break;
 		case 2:
-			if (target) {
-				if ((size_t)tarindex >= targsize)
+			if (*target) {
+				if (*target >= tarend)
 					return (-1);
-				target[tarindex]   |=  (pos - Base64) >> 2;
+				**target   |=  (pos - Base64) >> 2;
 				nextbyte = ((pos - Base64) & 0x03) << 6;
-				if ((size_t)tarindex + 1 < targsize)
-					target[tarindex + 1] = nextbyte;
+				if (*target + 1 < tarend)
+					(*target)[1] = nextbyte;
 				else if (nextbyte)
 					return (-1);
 			}
-			tarindex++;
+			(*target)++;
 			state = 3;
 			break;
 		case 3:
-			if (target) {
-				if ((size_t)tarindex >= targsize)
+			if (*target) {
+				if (*target >= tarend)
 					return (-1);
-				target[tarindex] |= (pos - Base64);
+				**target |= (pos - Base64);
 			}
-			tarindex++;
+			(*target)++;
 			state = 0;
 			break;
 		default:
@@ -302,8 +299,7 @@
 			 * zeros.  If we don't check them, they become a
 			 * subliminal channel.
 			 */
-			if (target && (size_t)tarindex < targsize &&
-			    target[tarindex] != 0)
+			if (*target && *target < tarend && **target != 0)
 				return (-1);
 		}
 	} else {
@@ -315,5 +311,11 @@
 			return (-1);
 	}
 
-	return (tarindex);
+	return (*target - orig);
+}
+
+int
+b64_pton(const char *src, unsigned char *target, size_t targsize)
+{
+	return b64_pton_partial(src, &target, targsize);
 }