TOTP

lib/Arduino-Base32-Decode/README.md

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+# Arduino libary for Base32 (rfc4648) decoding.
+
+
+## Traditional C interface
+
+### base32decode : decode a \0 terminated base32 encoded string.
+  
+    int base32decode(
+       const char * encoded, 
+       unsigned char * decodedBytes, 
+       size_t maxbuf
+    );
+
+#### inputs: 
+
+    encoded        \0 terminated char buffer with encoded string
+    decodedBytes   outputbuffer (or NULL)
+    maxbuff        size of the output buffer
+
+#### outputs:
+
+ returns the decoded byte array in decodedBytes and the length. Or if
+ decodedBytes==NULL, will just return the length needed; regardless of
+ the value of maxbuff.
+ 
+ If the size of maxbuff allows it - a terminating \0 is added (but not
+ including in the length returned) - as very often the decoded data
+ itself is actually again a string.
+
+
+## C++/INO/Arduino# tring interface
+
+### base32decodeToString - decode a String into a decoded String
+
+    int base32decodeToString(String encoded, String &decoded);
+
+#### inputs:
+    encoded   String with the encoded base32 value
+    &decoded  returned string (if any)
+
+#### outputs:  
+Will return the length of the decoded string or a negative
+ value on error. 
+
+
+# Example
+
+Typical use:
+
+    String in = "IFZGI5LJNZXSAUTVNRSXU===";
+    String out;
+
+    int r = base32decodeToString(in, out);
+    if (r < 0) {
+      Serial.println("Could not decode the string");
+      return;
+    };
+
+    Serial.print("Decoded: ");
+    Serial.println(out);