1 files changed, 5 insertions, 1 deletions

diff --git a/st.c b/st.c
index ede7ae6..a8f8232 100644
--- a/st.c
+++ b/st.c
@@ -366,7 +366,7 @@ char
 base64dec_getc(const char **src)
 {
         while (**src && !isprint(**src)) (*src)++;
-        return *((*src)++);
+        return **src ? *((*src)++) : '=';  /* emulate padding if string ends */
 }
 
 char *
@@ -384,6 +384,10 @@ base64dec(const char *src)
                 int c = base64_digits[(unsigned char) base64dec_getc(&src)];
                 int d = base64_digits[(unsigned char) base64dec_getc(&src)];
 
+                /* invalid input. 'a' can be -1, e.g. if src is "\n" (c-str) */
+                if (a == -1 || b == -1)
+                        break;
+
                 *dst++ = (a << 2) | ((b & 0x30) >> 4);
                 if (c == -1)
                         break;