From 1f27b416ad023094ea65ad5307918054c1289139 Mon Sep 17 00:00:00 2001
From: Klas Lindfors <klas@yubico.com>
Date: Fri, 9 Nov 2012 15:08:50 +0100
Subject: [PATCH] add ykp_ndef_as_text() to get the text back from YK_NDEF

---
 libykpers-1.map |  1 +
 ykpers.c        | 37 +++++++++++++++++++++++++++++++++++++
 ykpers.h        |  1 +
 3 files changed, 39 insertions(+)

diff --git a/libykpers-1.map b/libykpers-1.map
index 6bdf7d2..0ea98e6 100644
--- a/libykpers-1.map
+++ b/libykpers-1.map
@@ -166,5 +166,6 @@ LIBYKPERS_1.10 {
   global:
 # Functions:
   yk_write_ndef2;
+  ykp_ndef_as_text;
 # Variables:
 } LIBYKPERS_1.9;
diff --git a/ykpers.c b/ykpers.c
index 52aee82..12ead7d 100644
--- a/ykpers.c
+++ b/ykpers.c
@@ -445,6 +445,43 @@ int ykp_construct_ndef_text(YK_NDEF *ndef, const char *text, const char *lang, b
 	return 1;
 }
 
+int ykp_ndef_as_text(YK_NDEF *ndef, char *text, size_t len)
+{
+	if(ndef->type == 'U') {
+		const char *part = NULL;
+		size_t offset = 0;
+		if(ndef->data[0] > 0) {
+			part = ndef_identifiers[ndef->data[0] - 1];
+			offset = strlen(part);
+		}
+		if(offset + ndef->len - 1 > len) {
+			ykp_errno = YKP_EINVAL;
+			return 0;
+		}
+		if(part) {
+			memcpy(text, part, offset);
+		}
+		memcpy(text + offset, ndef->data + 1, ndef->len - 1);
+		text[ndef->len + offset] = 0;
+		return 1;
+	}
+	else if(ndef->type == 'T') {
+		unsigned char status = ndef->data[0];
+		if(status & 0x80)
+			status ^= 0x80;
+		if(ndef->len - status - 1 > len) {
+			ykp_errno = YKP_EINVAL;
+			return 0;
+		}
+		memcpy(text, ndef->data + status + 1, ndef->len - status - 1);
+		text[ndef->len - status] = 0;
+		return 1;
+	}
+	else {
+		return 0;
+	}
+}
+
 int ykp_set_ndef_access_code(YK_NDEF *ndef, unsigned char *access_code)
 {
 	if(ndef)
diff --git a/ykpers.h b/ykpers.h
index 9a142f0..4eeec6a 100644
--- a/ykpers.h
+++ b/ykpers.h
@@ -72,6 +72,7 @@ int ykp_free_ndef(YK_NDEF *ndef);
 int ykp_construct_ndef_uri(YK_NDEF *ndef, const char *uri);
 int ykp_construct_ndef_text(YK_NDEF *ndef, const char *text, const char *lang, bool isutf16);
 int ykp_set_ndef_access_code(YK_NDEF *ndef, unsigned char *access_code);
+int ykp_ndef_as_text(YK_NDEF *ndef, char *text, size_t len);
 
 int ykp_set_access_code(YKP_CONFIG *cfg, unsigned char *access_code, size_t len);
 int ykp_set_fixed(YKP_CONFIG *cfg, unsigned char *fixed, size_t len);
-- 
2.39.5