accept base64 encoding? about jose HOT 6 CLOSED

$ echo 'ix6oO88/Qid+iPbREThqOw==' | sed -e 's|\+|-|g' -e 's|/|_|g' -e 's|=||g'
ix6oO88_Qid-iPbREThqOw

diff --git a/lib/b64.c b/lib/b64.c
index 6223089..70f6e3a 100644
--- a/lib/b64.c
+++ b/lib/b64.c
@@ -185,11 +185,15 @@ jose_b64_dec(const json_t *i, void *o, size_t ol)
 
     if (json_unpack((json_t *) i, "s%", &b64, &len) < 0)
         return SIZE_MAX;
-
-    if (!o)
-        return b64_dlen(len);
-
-    return jose_b64_dec_buf(b64, len, o, ol);
+    size_t padding = 0;
+    for (size_t idx = 0; idx < len; idx++) {
+        if (b64[idx] == '=')
+            padding++;
+    }
+    if (!o) {
+        return b64_dlen(len - padding);
+    }
+    return jose_b64_dec_buf(b64, len - padding, o, ol);
 }
 
 jose_io_t *
@@ -231,8 +235,24 @@ jose_b64_dec_buf(const void *i, size_t il, void *o, size_t ol)
 
     for (size_t io = 0; io < il; io++) {
         uint8_t v = 0;
-
-        for (const char c = e[io]; v < len && c != map[v]; v++)
+        bool skip = false;
+
+        for (const char c = e[io]; v < len && c != map[v]; v++) {
+            if (c == '+') {
+                v=62;
+                break;
+            }
+            if (c == '/') {
+                v=63;
+                break;
+            }
+            if (c == '=') {
+                skip = true;
+                break;
+            }
+            continue;
+        }
+        if (skip)
             continue;
 
         if (v >= len)
--