1 files changed, 37 insertions, 0 deletions
diff --git a/utils/base64_decode.c b/utils/base64_decode.c
new file mode 100644
index 00000000..4f00f196
--- /dev/null
+++ b/utils/base64_decode.c
@@ -0,0 +1,37 @@
+#include "misc.h"
+
+void base64_decode_bs(BinarySink *bs, ptrlen input)
+{
+    BinarySource src[1];
+    BinarySource_BARE_INIT_PL(src, input);
+
+    while (get_avail(src)) {
+        char b64atom[4];
+        unsigned char binatom[3];
+
+        for (size_t i = 0; i < 4 ;) {
+            char c = get_byte(src);
+            if (get_err(src))
+                c = '=';
+            if (c == '\n' || c == '\r')
+                continue;
+            b64atom[i++] = c;
+        }
+
+        put_data(bs, binatom, base64_decode_atom(b64atom, binatom));
+    }
+}
+
+void base64_decode_fp(FILE *fp, ptrlen input)
+{
+    stdio_sink ss;
+    stdio_sink_init(&ss, fp);
+    base64_decode_bs(BinarySink_UPCAST(&ss), input);
+}
+
+strbuf *base64_decode_sb(ptrlen input)
+{
+    strbuf *sb = strbuf_new_nm();
+    base64_decode_bs(BinarySink_UPCAST(sb), input);
+    return sb;
+}