BUG: Replace strncpy with snprintf to ensure NUL termination

GCC's -Wstringop-truncation flagged 6 calls in itkScancoImageIO.cxx
where strncpy was invoked with a bound equal to the destination size.
When the source string is at least as long as the destination, strncpy
leaves the buffer without a NUL terminator, causing undefined behavior
in subsequent C-string accessors (GetVersion, GetPatientName, etc.).

The in-memory header buffers (m_Version[18], m_PatientName[42],
m_CreationDate[32], m_ModificationDate[32], m_RescaleUnits[18],
m_CalibrationData[66]) are explicitly sized two bytes wider than the
on-disk fixed-width fields (16, 40, 8/decoded-32, 32, 16, 64) so that a
NUL terminator always fits; itkISQHeaderIO.cxx:137 documents this with
an explicit '\\0' write.

Switch all six metadata-import sites and the five (six counting
ModificationDate) public Set*() inline accessors to
std::snprintf(dst, sizeof(dst), "%s", src), which always
NUL-terminates and silently truncates oversized input. Add <cstdio> to
both translation units.

Author: hjmjohnson

include/itkScancoImageIO.h

@@ -55,6 +55,7 @@
 #include "IOScancoExport.h"
 
 
+#include <cstdio>
 #include <fstream>
 #include "itkImageIOBase.h"
 #include "itkScancoDataManipulation.h"
@@ -167,7 +168,7 @@ class IOScanco_EXPORT ScancoImageIO : public ImageIOBase
   void
   SetVersion(const char * version)
   {
-    strncpy(this->m_HeaderData.m_Version, version, 18);
+    std::snprintf(this->m_HeaderData.m_Version, sizeof(this->m_HeaderData.m_Version), "%s", version);
     this->Modified();
   }
 
@@ -179,7 +180,8 @@ class IOScanco_EXPORT ScancoImageIO : public ImageIOBase
   void
   SetCalibrationData(const char * calibrationData)
   {
-    strncpy(this->m_HeaderData.m_CalibrationData, calibrationData, 66);
+    std::snprintf(
+      this->m_HeaderData.m_CalibrationData, sizeof(this->m_HeaderData.m_CalibrationData), "%s", calibrationData);
     this->Modified();
   }
 
@@ -191,7 +193,8 @@ class IOScanco_EXPORT ScancoImageIO : public ImageIOBase
   void
   SetRescaleUnits(const char * rescaleUnits)
   {
-    strncpy(this->m_HeaderData.m_RescaleUnits, rescaleUnits, 18);
+    std::snprintf(
+      this->m_HeaderData.m_RescaleUnits, sizeof(this->m_HeaderData.m_RescaleUnits), "%s", rescaleUnits);
     this->Modified();
   }
 
@@ -284,7 +287,7 @@ class IOScanco_EXPORT ScancoImageIO : public ImageIOBase
   void
   SetPatientName(const char * patientName)
   {
-    strncpy(this->m_HeaderData.m_PatientName, patientName, 42);
+    std::snprintf(this->m_HeaderData.m_PatientName, sizeof(this->m_HeaderData.m_PatientName), "%s", patientName);
     this->Modified();
   }
 
@@ -296,7 +299,8 @@ class IOScanco_EXPORT ScancoImageIO : public ImageIOBase
   void
   SetCreationDate(const char * creationDate)
   {
-    strncpy(this->m_HeaderData.m_CreationDate, creationDate, 32);
+    std::snprintf(
+      this->m_HeaderData.m_CreationDate, sizeof(this->m_HeaderData.m_CreationDate), "%s", creationDate);
     this->Modified();
   }
 
@@ -308,7 +312,10 @@ class IOScanco_EXPORT ScancoImageIO : public ImageIOBase
   void
   SetModificationDate(const char * modificationDate)
   {
-    strncpy(this->m_HeaderData.m_ModificationDate, modificationDate, 32);
+    std::snprintf(this->m_HeaderData.m_ModificationDate,
+                  sizeof(this->m_HeaderData.m_ModificationDate),
+                  "%s",
+                  modificationDate);
     this->Modified();
   }
 

src/itkScancoImageIO.cxx

@@ -42,6 +42,7 @@
 #include "itkISQHeaderIO.h"
 
 #include <algorithm>
+#include <cstdio>
 #include <ctime>
 #include <filesystem>
 
@@ -354,23 +355,28 @@ ScancoImageIO::SetHeaderFromMetaDataDictionary()
   std::string stringMeta;
   if (ExposeMetaData<std::string>(metaData, "Version", stringMeta))
   {
-    strncpy(this->m_HeaderData.m_Version, stringMeta.c_str(), 18);
+    std::snprintf(this->m_HeaderData.m_Version, sizeof(this->m_HeaderData.m_Version), "%s", stringMeta.c_str());
   }
   if (ExposeMetaData<std::string>(metaData, "PatientName", stringMeta))
   {
-    strncpy(this->m_HeaderData.m_PatientName, stringMeta.c_str(), 42);
+    std::snprintf(
+      this->m_HeaderData.m_PatientName, sizeof(this->m_HeaderData.m_PatientName), "%s", stringMeta.c_str());
   }
 
   ExposeMetaData<int>(metaData, "PatientIndex", this->m_HeaderData.m_PatientIndex);
   ExposeMetaData<int>(metaData, "ScannerID", this->m_HeaderData.m_ScannerID);
 
   if (ExposeMetaData<std::string>(metaData, "CreationDate", stringMeta))
   {
-    strncpy(this->m_HeaderData.m_CreationDate, stringMeta.c_str(), 32);
+    std::snprintf(
+      this->m_HeaderData.m_CreationDate, sizeof(this->m_HeaderData.m_CreationDate), "%s", stringMeta.c_str());
   }
   if (ExposeMetaData<std::string>(metaData, "ModificationDate", stringMeta))
   {
-    strncpy(this->m_HeaderData.m_ModificationDate, stringMeta.c_str(), 32);
+    std::snprintf(this->m_HeaderData.m_ModificationDate,
+                  sizeof(this->m_HeaderData.m_ModificationDate),
+                  "%s",
+                  stringMeta.c_str());
   }
 
   ExposeMetaData<double>(metaData, "SliceThickness", this->m_HeaderData.m_SliceThickness);
@@ -399,11 +405,13 @@ ScancoImageIO::SetHeaderFromMetaDataDictionary()
   ExposeMetaData<int>(metaData, "RescaleType", this->m_HeaderData.m_RescaleType);
   if (ExposeMetaData<std::string>(metaData, "RescaleUnits", stringMeta))
   {
-    strncpy(this->m_HeaderData.m_RescaleUnits, stringMeta.c_str(), 18);
+    std::snprintf(
+      this->m_HeaderData.m_RescaleUnits, sizeof(this->m_HeaderData.m_RescaleUnits), "%s", stringMeta.c_str());
   }
   if (ExposeMetaData<std::string>(metaData, "CalibrationData", stringMeta))
   {
-    strncpy(this->m_HeaderData.m_CalibrationData, stringMeta.c_str(), 66);
+    std::snprintf(
+      this->m_HeaderData.m_CalibrationData, sizeof(this->m_HeaderData.m_CalibrationData), "%s", stringMeta.c_str());
   }
 
   ExposeMetaData<double>(metaData, "RescaleSlope", this->m_HeaderData.m_RescaleSlope);