diff --git a/CHANGELOG.md b/CHANGELOG.md index 617951345..c60483e67 100644 --- a/CHANGELOG.md +++ b/CHANGELOG.md @@ -109,6 +109,7 @@ - NFC: - Added 6 new Mifare Classic keys from Bulgaria Hotel (#216 by @z3r0l1nk) - NDEF parser supports NTAG I2C Plus 1k and 2k chips too (by @RocketGod-git) + - NDEF parser decodes URL-encoded URI characters (#267 by @jaylikesbunda) - UL: Add iq aparts hotel key (by @xMasterX) - OFW/UL: Rename 'Detect Reader' to 'Extract MFC Keys' (by @bettse & @xMasterX) - OFW: Plantain parser improvements (by @assasinfil) diff --git a/applications/main/nfc/plugins/supported_cards/ndef.c b/applications/main/nfc/plugins/supported_cards/ndef.c index 05b31f32b..45809c847 100644 --- a/applications/main/nfc/plugins/supported_cards/ndef.c +++ b/applications/main/nfc/plugins/supported_cards/ndef.c @@ -27,11 +27,7 @@ static void print_data(FuriString* str, const char* prefix, const uint8_t* buf, size_t len, bool force_hex) { if(prefix) furi_string_cat_printf(str, "%s: ", prefix); if(!force_hex && is_text(buf, len)) { - char* tmp = malloc(len + 1); - memcpy(tmp, buf, len); - tmp[len] = '\0'; - furi_string_cat_printf(str, "%s", tmp); - free(tmp); + furi_string_cat_printf(str, "%.*s", len, buf); } else { for(uint8_t i = 0; i < len; i++) { furi_string_cat_printf(str, "%02X ", buf[i]); @@ -40,6 +36,17 @@ static void furi_string_cat(str, "\n"); } +static inline uint8_t hex_to_int(char c) { + if(c >= '0' && c <= '9') return c - '0'; + if(c >= 'A' && c <= 'F') return c - 'A' + 10; + if(c >= 'a' && c <= 'f') return c - 'a' + 10; + return 0; +} + +static char decode_char(const char* str) { + return (hex_to_int(str[1]) << 4) | hex_to_int(str[2]); +} + static void parse_ndef_uri(FuriString* str, const uint8_t* payload, uint32_t payload_len) { // https://learn.adafruit.com/adafruit-pn532-rfid-nfc/ndef#uri-records-0x55-slash-u-607763 const char* prepends[] = { @@ -88,26 +95,44 @@ static void parse_ndef_uri(FuriString* str, const uint8_t* payload, uint32_t pay size_t prepend_len = strlen(prepend); size_t uri_len = prepend_len + (payload_len - 1); - char* const uri_buf = malloc(uri_len); + char* const uri_buf = malloc(uri_len); // const to keep the original pointer to free later memcpy(uri_buf, prepend, prepend_len); memcpy(uri_buf + prepend_len, payload + 1, payload_len - 1); - char* uri = uri_buf; + char* uri = uri_buf; // cursor we can iterate and shift freely + + // Encoded chars take 3 bytes (%AB), decoded chars take 1 byte + // We can decode by iterating and overwriting the same buffer + size_t decoded_len = 0; + for(size_t encoded_idx = 0; encoded_idx < uri_len; encoded_idx++) { + if(uri[encoded_idx] == '%' && encoded_idx + 2 < uri_len) { + char hi = toupper(uri[encoded_idx + 1]); + char lo = toupper(uri[encoded_idx + 2]); + if(((hi >= 'A' && hi <= 'F') || (hi >= '0' && hi <= '9')) && + ((lo >= 'A' && lo <= 'F') || (lo >= '0' && lo <= '9'))) { + uri[decoded_len++] = decode_char(&uri[encoded_idx]); + encoded_idx += 2; + continue; + } + } + uri[decoded_len++] = uri[encoded_idx]; + } const char* type = "URI"; - if(strncmp(uri, "http", strlen("http")) == 0) { + if(strncmp(uri, "http", 4) == 0) { type = "URL"; - } else if(strncmp(uri, "tel:", strlen("tel:")) == 0) { + } else if(strncmp(uri, "tel:", 4) == 0) { type = "Phone"; - uri += strlen("tel:"); - uri_len -= strlen("tel:"); - } else if(strncmp(uri, "mailto:", strlen("mailto:")) == 0) { + uri += 4; + decoded_len -= 4; + } else if(strncmp(uri, "mailto:", 7) == 0) { type = "Mail"; - uri += strlen("mailto:"); - uri_len -= strlen("mailto:"); + uri += 7; + decoded_len -= 7; } furi_string_cat_printf(str, "%s\n", type); - print_data(str, NULL, (uint8_t*)uri, uri_len, false); + print_data(str, NULL, (uint8_t*)uri, decoded_len, false); + free(uri_buf); }