diff --git a/lib/roken/Makefile.am b/lib/roken/Makefile.am
index 26554dc19..5532c417f 100644
--- a/lib/roken/Makefile.am
+++ b/lib/roken/Makefile.am
@@ -20,7 +20,7 @@ if HAVE_DBHEADER
 AM_CPPFLAGS += -I$(DBHEADER)
 endif
 
-noinst_PROGRAMS = snprintf-test resolve-test rkpty test-detach test-auxval rkvis
+noinst_PROGRAMS = snprintf-test resolve-test rkpty test-detach test-auxval rkvis rkbase64
 
 CHECK_LOCAL = snprintf-test resolve-test rkpty make-roken
 
@@ -60,6 +60,9 @@ test_getuserinfo_LDADD = libtest.la $(LDADD)
 rkvis_SOURCES = vis.c
 rkvis_CPPFLAGS = -DTEST
 
+rkbase64_SOURCES = base64.c
+rkbase64_CPPFLAGS = -DTEST
+
 test_detach_SOURCES = test-detach.c
 
 rkpty_LDADD = $(LIB_openpty) $(LDADD)
diff --git a/lib/roken/base64.c b/lib/roken/base64.c
index ddb733c52..a6dacdd1d 100644
--- a/lib/roken/base64.c
+++ b/lib/roken/base64.c
@@ -37,7 +37,13 @@
 #include <stdlib.h>
 #include <string.h>
 #include <limits.h>
+#ifdef TEST
+#include <stdio.h>
+#include <getarg.h>
+#include <err.h>
+#endif
 #include "base64.h"
+#include "roken.h"
 
 static const char base64_chars[] =
     "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
@@ -148,3 +154,105 @@ rk_base64_decode(const char *str, void *data)
     }
     return q - (unsigned char *) data;
 }
+
+#ifdef TEST
+static int decode_flag;
+static int help_flag;
+
+/*
+ * The short options are compatible with a subset of the FreeBSD contrib
+ * vis(1).  Heimdal additions have long option names only.
+ */
+static struct getargs args[] = {
+    { "decode", 'd', arg_flag, &decode_flag, "Decode", NULL },
+    { "help", 'h', arg_flag, &help_flag, "Print help message", NULL },
+};
+static size_t num_args = sizeof(args)/sizeof(args[0]);
+
+int
+main(int argc, char **argv)
+{
+    unsigned char *buf = NULL;
+    size_t buflen = 0;
+    size_t bufsz = 0;
+    int goptind = 0;
+    int ret;
+
+    setprogname("rkbase64");
+    if (getarg(args, num_args, argc, argv, &goptind) || help_flag) {
+        arg_printusage(args, num_args, NULL, "FILE | -");
+        return help_flag ? 0 : 1;
+    }
+
+    argc -= goptind;
+    argv += goptind;
+
+    if (help_flag)
+        return arg_printusage(args, num_args, NULL, "FILE | -- -"), 0;
+    if (argc != 1)
+        return arg_printusage(args, num_args, NULL, "FILE | -- -"), 1;
+
+    if (strcmp(argv[0], "-") == 0) {
+        unsigned char *tmp;
+        unsigned char d[4096];
+        size_t bytes;
+
+        while (!feof(stdin) && !ferror(stdin)) {
+            bytes = fread(d, 1, sizeof(d), stdin);
+            if (bytes == 0)
+                continue;
+            if (buflen + bytes > bufsz) {
+                if ((tmp = realloc(buf, bufsz + (bufsz >> 2) + sizeof(d))) == NULL)
+                    err(1, "Could not read stdin");
+                buf = tmp;
+                bufsz = bufsz + (bufsz >> 2) + sizeof(d);
+            }
+            memcpy(buf + buflen, d, bytes);
+            buflen += bytes;
+        }
+        if (ferror(stdin))
+            err(1, "Could not read stdin");
+    } else {
+        void *d;
+        if ((ret = rk_undumpdata(argv[0], &d, &bufsz)))
+            err(1, "Could not read %s", argv[0]);
+        buflen = bufsz;
+        buf = d;
+    }
+
+    if (decode_flag) {
+        unsigned char *d;
+
+        if (buflen == bufsz) {
+            unsigned char *tmp;
+
+            if ((tmp = realloc(buf, bufsz + 1)) == NULL)
+                err(1, "Could not decode data");
+            buf = tmp;
+            bufsz++;
+        }
+        buf[buflen] = '\0';
+
+        if ((d = malloc(buflen * 3 / 4 + 4)) == NULL)
+            err(1, "Could not decode data");
+
+        if ((ret = rk_base64_decode((const char *)buf, d)) < 0)
+            err(1, "Could not decode data");
+        if (fwrite(d, ret, 1, stdout) != 1)
+            err(1, "Could not write decoded data");
+        free(d);
+    } else {
+        char *e;
+
+        if ((ret = rk_base64_encode(buf, buflen, &e)) < 0)
+            err(1, "Could not encode data");
+        if (fwrite(e, ret, 1, stdout) != 1)
+            err(1, "Could not write decoded data");
+        free(e);
+        if (fwrite("\n", 1, 1, stdout) != 1)
+            err(1, "Could not write decoded data");
+    }
+    free(buf);
+    return 0;
+}
+#endif