Switched to using bash arrays to hold split versions of key instead of temp files.

asc2qr.sh

@@ -28,7 +28,7 @@
 
 # Maximum chuck size to send to the QR encoder. QR version 40 supports
 # 2,953 bytes of storage.
-file_split_size=2800
+max_qr_bytes=2800
 
 # Prefix string for the PNG images that are produced
 image_prefix="QR"
@@ -45,38 +45,27 @@ if [ ! -f ${asc_key} ]; then
 	exit 1
 fi
 
-# Create a temp file to use as a pattern for splitting the input key file.
-# This helps protect against file collisions in the current directory.
-export TMPDIR=""
-tmp_file=$(mktemp keyparts.XXXXXX)
-if [ $? -ne 0 ]; then
-	echo "failed to create temporary file"
-	exit 1
-fi
+## Split the key file into usable chunks that the QR encoder can consume
+chunks=()
+while true; do
+    s=$( head -c ${max_qr_bytes} )
+    echo "$s"
+    if [ ${#s} -gt 0 ]; then
+        chunks+=("${s}")
+    else
+        break
+    fi
+done <<< "$( cat ${asc_key} )"
 
-# Split the key file into usable chunks that the QR encoder can consume
-split -b ${file_split_size} ${asc_key} "${tmp_file}."
-
-# For each chunk, encode it into a qc image
+## For each chunk, encode it into a qr image
 index=1
-for file in ${tmp_file}.*; do
-	img="${image_prefix}${index}.png"
-	echo "generating ${img}"
-	cat ${file} | qrencode -o ${img}
+for c in "${chunks[@]}"; do
+    img="${image_prefix}${index}.png"
+    echo "generating ${img}"
+    echo -n "${c}" | qrencode -o ${img}
 	if [ $? -ne 0 ]; then
 		echo "failed to encode image"
 		exit 2
 	fi
 	index=$((index+1))
 done
-
-# Find the correct secure deletion utility (srm on Mac, shred on Linux)
-sec_del="srm"
-which ${sec_del} 2>&1 1>/dev/null
-if [ $? -ne 0 ]; then
-	sec_del="shred --remove"
-fi
-
-# Securely clean up temporary files
-${sec_del} ${tmp_file}
-${sec_del} ${tmp_file}.*

qr2asc.sh

@@ -43,6 +43,7 @@ if [ $? -ne 0 ]; then
 fi
 
 # For each image on the command line, decode it into text
+chunks=()
 index=1
 for img in "$@"; do
 	if [ ! -f ${img} ]; then
@@ -51,24 +52,19 @@ for img in "$@"; do
 	fi
 	asc_key="${tmp_file}.${index}"
 	echo "decoding ${img}"
-	zbarimg --raw ${img} 2>/dev/null | perl -p -e 'chomp if eof' > ${asc_key}
+    chunk=$( zbarimg --raw ${img} 2>/dev/null | perl -p -e 'chomp if eof' )
 	if [ $? -ne 0 ]; then
 		echo "failed to decode QR image"
 		exit 2
 	fi
+    chunks+=("${chunk}")
 	index=$((index+1))
 done
 
+asc_key=""
+for c in "${chunks[@]}"; do
+    asc_key+="${c}"
+done
+
 echo "creating ${output_key_name}"
-cat ${tmp_file}.* > ${output_key_name}
-
-# Find the correct secure deletion utility (srm on Mac, shred on Linux)
-sec_del="srm"
-which ${sec_del} 2>&1 1>/dev/null
-if [ $? -ne 0 ]; then
-	sec_del="shred --remove"
-fi
-
-# Securely clean up temporary files
-${sec_del} ${tmp_file}
-${sec_del} ${tmp_file}.*
+echo "${asc_key}" > ${output_key_name}