SMPKeyBin: Make key base filename compatible to FAT32 Long filename (LFN)v2.2.6

Previous scheme : `bd_C0:26:DA:01:DA:B1:1.smpkey.bin'

FAT32 LFN scheme: `bd_C0_26_DA_01_DA_B1_1-smpkey.bin'

Tested interoperability with native and java test application.

3 files changed, 51 insertions, 8 deletions

diff --git a/api/direct_bt/SMPKeyBin.hpp b/api/direct_bt/SMPKeyBin.hpp
index 9844d0e8..7b77444b 100644
--- a/api/direct_bt/SMPKeyBin.hpp
+++ b/api/direct_bt/SMPKeyBin.hpp
@@ -48,6 +48,16 @@ namespace direct_bt {
  * implementation supports mixed mode for certain devices.
  * E.g. LTK responder key only etc.
  * </p>
+ * <p>
+ * Filename as retrieved by SMPKeyBin::getFileBasename()
+ * has the following form `bd_C0_26_DA_01_DA_B1_1-smpkey.bin`:
+ * <ul>
+ * <li>{@code 'bd_'} denotes prefix</li>
+ * <li>{@code 'C0_26_DA_01_DA_B1'} denotes the {@link EUI48} address</li>
+ * <li>{@code '_1'} denotes the {@link BDAddressType}</li>
+ * <li>{@code '-smpkey.bin'} denotes the suffix</li>
+ * </li>
+ * </p>
  */
 class SMPKeyBin {
     public:
@@ -276,12 +286,16 @@ class SMPKeyBin {
 
         std::string toString() const noexcept;
 
-        std::string getFileBasename() const noexcept {
-            return "bd_"+addrAndType.address.toString()+":"+std::to_string(number(addrAndType.type))+".smpkey.bin";
-        }
-        static std::string getFileBasename(const BDAddressAndType& addrAndType_) {
-            return "bd_"+addrAndType_.address.toString()+":"+std::to_string(number(addrAndType_.type))+".smpkey.bin";
-        }
+        /**
+         * Returns the base filename, see SMPKeyBin API doc for naming scheme.
+         */
+        std::string getFileBasename() const noexcept;
+
+        /**
+         * Returns the base filename, see SMPKeyBin API doc for naming scheme.
+         */
+        static std::string getFileBasename(const BDAddressAndType& addrAndType_);
+
         static std::string getFilename(const std::string& path, const BDAddressAndType& addrAndType_) {
             return path + "/" + getFileBasename(addrAndType_);
         }
diff --git a/java/org/direct_bt/SMPKeyBin.java b/java/org/direct_bt/SMPKeyBin.java
index d0fa80ba..b8dff758 100644
--- a/java/org/direct_bt/SMPKeyBin.java
+++ b/java/org/direct_bt/SMPKeyBin.java
@@ -46,6 +46,16 @@ import org.direct_bt.SMPKeyMask.KeyType;
  * implementation supports mixed mode for certain devices.
  * E.g. LTK responder key only etc.
  * </p>
+ * <p>
+ * Filename as retrieved by {@link #getFileBasename(BDAddressAndType)} and {@link #getFileBasename()}
+ * has the following form '{@code bd_C0_26_DA_01_DA_B1_1-smpkey.bin}':
+ * <ul>
+ * <li>{@code 'bd_'} denotes prefix</li>
+ * <li>{@code 'C0_26_DA_01_DA_B1'} denotes the {@link EUI48} address</li>
+ * <li>{@code '_1'} denotes the {@link BDAddressType}</li>
+ * <li>{@code '-smpkey.bin'} denotes the suffix</li>
+ * </li>
+ * </p>
  */
 public class SMPKeyBin {
         public static final short VERSION = (short)0b0101010101010101 + (short)2; // bitpattern + version
@@ -325,11 +335,19 @@ public class SMPKeyBin {
                    ( !hasLTKResp() || ltk_resp.isValid() );
         }
 
+        /**
+         * Returns the base filename, see {@link SMPKeyBin} API doc for naming scheme.
+         */
         final public String getFileBasename() {
-            return "bd_"+addrAndType.address.toString()+":"+addrAndType.type.value+".smpkey.bin";
+            final String r = "bd_"+addrAndType.address.toString()+":"+addrAndType.type.value+"-smpkey.bin";
+            return r.replace(':', '_');
         }
+        /**
+         * Returns the base filename, see {@link SMPKeyBin} API doc for naming scheme.
+         */
         final public static String getFileBasename(final BDAddressAndType addrAndType_) {
-            return "bd_"+addrAndType_.address.toString()+":"+addrAndType_.type.value+".smpkey.bin";
+            final String r = "bd_"+addrAndType_.address.toString()+":"+addrAndType_.type.value+"-smpkey.bin";
+            return r.replace(':', '_');
         }
         final public static String getFilename(final String path, final BDAddressAndType addrAndType_) {
             return path + "/" + getFileBasename(addrAndType_);
diff --git a/src/direct_bt/SMPKeyBin.cpp b/src/direct_bt/SMPKeyBin.cpp
index e9fbbac2..252d747e 100644
--- a/src/direct_bt/SMPKeyBin.cpp
+++ b/src/direct_bt/SMPKeyBin.cpp
@@ -138,6 +138,17 @@ std::string SMPKeyBin::toString() const noexcept {
     return res;
 }
 
+std::string SMPKeyBin::getFileBasename() const noexcept {
+    std::string r("bd_"+addrAndType.address.toString()+":"+std::to_string(number(addrAndType.type))+"-smpkey.bin");
+    std::replace( r.begin(), r.end(), ':', '_');
+    return r;
+}
+std::string SMPKeyBin::getFileBasename(const BDAddressAndType& addrAndType_) {
+    std::string r("bd_"+addrAndType_.address.toString()+":"+std::to_string(number(addrAndType_.type))+"-smpkey.bin");
+    std::replace( r.begin(), r.end(), ':', '_');
+    return r;
+}
+
 bool SMPKeyBin::remove_impl(const std::string& fname) {
 #if USE_CXX17lib_FS
     const fs::path fname2 = fname;