Fixed writing the tag thanks to @boardhead explaining encipher/decipher.

Sadly, ArrayCfg/crpyt does not know if he's encrypting/decrypting. I've added a sniff in TiffEncoder::visitBinaryArrayEnd to avoid changing the API. Let's change the API in v0.28 (but not yet on master).
Exiv2 · Jun 21, 2019 · c89dc37 · c89dc37
1 parent 23f1aa9
commit c89dc37
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Showing 5 changed files with 26 additions and 7 deletions.
diff --git a/src/sonymn_int.cpp b/src/sonymn_int.cpp
@@ -811,14 +811,18 @@ namespace Exiv2 {
         return tagInfoFp_;
     }
 
-    DataBuf sonyTagDecipher(uint16_t /* tag */, const byte* bytes, uint32_t size, TiffComponent* const /*object*/)
+    DataBuf sonyTagCipher(uint16_t /* tag */, const byte* bytes, uint32_t size, TiffComponent* const /*object*/, bool bDecipher)
     {
         DataBuf b(bytes,size); // copy the data
 
         // initialize the code table
         byte  code[256];
         for ( uint32_t i = 0 ; i < 249 ; i++ ) {
-            code[(i * i * i) % 249] = i ;
+            if ( bDecipher ) {
+                code[(i * i * i) % 249] = i ;
+            } else {
+                code[i] = (i * i * i) % 249 ;
+            }
         }
         for ( uint32_t i = 249 ; i < 256 ; i++ ) {
             code[i] = i;
@@ -832,4 +836,13 @@ namespace Exiv2 {
         return b;
     }
 
+    DataBuf sonyTagDecipher(uint16_t tag, const byte* bytes, uint32_t size, TiffComponent* const object)
+    {
+        return sonyTagCipher(tag,bytes,size,object,true);
+    }
+    DataBuf sonyTagEncipher(uint16_t tag, const byte* bytes, uint32_t size, TiffComponent* const object)
+    {
+        return sonyTagCipher(tag,bytes,size,object,false);
+    }
+
 }}                                      // namespace Internal, Exiv2
diff --git a/src/sonymn_int.hpp b/src/sonymn_int.hpp
@@ -78,7 +78,9 @@ namespace Exiv2 {
 
     }; // class SonyMakerNote
 
+    DataBuf sonyTagCipher  (uint16_t, const byte*, uint32_t, TiffComponent* const, bool bCipher);
     DataBuf sonyTagDecipher(uint16_t, const byte*, uint32_t, TiffComponent* const);
+    DataBuf sonyTagEncipher(uint16_t, const byte*, uint32_t, TiffComponent* const);
 
 }}                                      // namespace Internal, Exiv2
 

diff --git a/src/tiffvisitor_int.cpp b/src/tiffvisitor_int.cpp
@@ -36,6 +36,7 @@
 #include "value.hpp"
 #include "image.hpp"
 #include "jpgimage.hpp"
+#include "sonymn_int.hpp"
 #include "i18n.h"             // NLS support.
 
 // + standard includes
@@ -780,7 +781,10 @@ namespace Exiv2 {
         if (!object->initialize(pRoot_)) return;
 
         // Re-encrypt buffer if necessary
-        const CryptFct cryptFct = object->cfg()->cryptFct_;
+        CryptFct cryptFct = object->cfg()->cryptFct_;
+        if ( cryptFct == sonyTagDecipher ) {
+             cryptFct  = sonyTagEncipher;
+        }
         if (cryptFct != 0) {
             const byte* pData = object->pData();
             DataBuf buf = cryptFct(object->tag(), pData, size, pRoot_);

diff --git a/test/data/exiv2-pr906.exv b/test/data/exiv2-pr906.exv
diff --git a/tests/bugfixes/github/test_pr_906.py b/tests/bugfixes/github/test_pr_906.py
@@ -7,10 +7,10 @@ class Sony2FpTest(metaclass=CaseMeta):
     filename = path("$data_path/exiv2-pr906.exv")
     commands = ["$exiv2 -pa --grep Sony2Fp $filename"]
 
-    stdout = ["""Exif.Sony2Fp.AmbientTemperature              SByte       1  73
-Exif.Sony2Fp.FocusMode                       Byte        1  42
-Exif.Sony2Fp.AFAreaMode                      Byte        1  3
-Exif.Sony2Fp.FocusPosition2                  Byte        1  179
+    stdout = ["""Exif.Sony2Fp.AmbientTemperature              SByte       1  19
+Exif.Sony2Fp.FocusMode                       Byte        1  6
+Exif.Sony2Fp.AFAreaMode                      Byte        1  12
+Exif.Sony2Fp.FocusPosition2                  Byte        1  140
 """
     ]
     stderr = [""]