From 4aeb5f46149417e158352b9b977152fc8f8fcc40 Mon Sep 17 00:00:00 2001
From: Eric Betts <bettse@fastmail.fm>
Date: Sun, 14 Apr 2024 14:43:22 -0700
Subject: [PATCH] add C1k35s

---
 plugin_wiegand.c | 53 ++++++++++++++++++++++++++++++++++++++++++++----
 1 file changed, 49 insertions(+), 4 deletions(-)

diff --git a/plugin_wiegand.c b/plugin_wiegand.c
index 947665f9d7c..51d69734391 100644
--- a/plugin_wiegand.c
+++ b/plugin_wiegand.c
@@ -9,11 +9,51 @@
  * https://github.com/RfidResearchGroup/proxmark3/blob/master/client/src/wiegand_formats.c
  */
 
-static int wiegand_h10301_parse(uint8_t bit_length, uint64_t bits, FuriString* description) {
-    UNUSED(description);
-    UNUSED(bits);
-    UNUSED(bit_length);
+// Structure for packed wiegand messages
+// Always align lowest value (last transmitted) bit to ordinal position 0 (lowest valued bit bottom)
+typedef struct {
+    uint8_t Length; // Number of encoded bits in wiegand message (excluding headers and preamble)
+    uint32_t Top; // Bits in x<<64 positions
+    uint32_t Mid; // Bits in x<<32 positions
+    uint32_t Bot; // Lowest ordinal positions
+} wiegand_message_t;
+
+static inline uint8_t oddparity32(uint32_t x) {
+    return bit_lib_test_parity_32(x, BitLibParityOdd);
+}
+
+static inline uint8_t evenparity32(uint32_t x) {
+    return bit_lib_test_parity_32(x, BitLibParityEven);
+}
 
+static int wiegand_C1k35s_parse(uint8_t bit_length, uint64_t bits, FuriString* description) {
+    if(bit_length != 35) {
+        return 0;
+    }
+
+    wiegand_message_t value;
+    value.Mid = bits >> 32;
+    value.Bot = bits;
+    wiegand_message_t* packed = &value;
+
+    uint32_t cn = (packed->Bot >> 1) & 0x000FFFFF;
+    uint32_t fc = ((packed->Mid & 1) << 11) | ((packed->Bot >> 21));
+    bool valid = (evenparity32((packed->Mid & 0x1) ^ (packed->Bot & 0xB6DB6DB6)) ==
+                  ((packed->Mid >> 1) & 1)) &&
+                 (oddparity32((packed->Mid & 0x3) ^ (packed->Bot & 0x6DB6DB6C)) ==
+                  ((packed->Bot >> 0) & 1)) &&
+                 (oddparity32((packed->Mid & 0x3) ^ (packed->Bot & 0xFFFFFFFF)) ==
+                  ((packed->Mid >> 2) & 1));
+
+    if(valid) {
+        furi_string_cat_printf(description, "C1k35s\nFC: %ld CN: %ld\n", fc, cn);
+        return 1;
+    }
+
+    return 0;
+}
+
+static int wiegand_h10301_parse(uint8_t bit_length, uint64_t bits, FuriString* description) {
     if(bit_length != 26) {
         return 0;
     }
@@ -60,6 +100,7 @@ static int wiegand_format_count(uint8_t bit_length, uint64_t bits) {
     FuriString* ignore = furi_string_alloc();
 
     count += wiegand_h10301_parse(bit_length, bits, ignore);
+    count += wiegand_C1k35s_parse(bit_length, bits, ignore);
 
     furi_string_free(ignore);
 
@@ -82,6 +123,10 @@ static void wiegand_format_description(
     if(i - 1 == index) {
         return;
     }
+    i += wiegand_C1k35s_parse(bit_length, bits, description);
+    if(i - 1 == index) {
+        return;
+    }
 
     furi_string_cat_printf(description, "[%i] <name> FC: CN:", index);
 }