From 15bbe379861c671a2e9b6dc5ac2583625c489033 Mon Sep 17 00:00:00 2001
From: rjaeckel <robert.jaeckel@itz.uni-halle.de>
Date: Sat, 30 Jan 2016 20:54:10 +0100
Subject: [PATCH 1/5] bugfix as openssl 1.0.2 does not accept a key longer than
 64Bytes in hex

openssl 1.0.1 just strips the key
---
 ocdec.sh | 1 +
 1 file changed, 1 insertion(+)

diff --git a/ocdec.sh b/ocdec.sh
index 1388c2f..2f682d0 100755
--- a/ocdec.sh
+++ b/ocdec.sh
@@ -124,6 +124,7 @@ function decryptFile() {
 
   decFileKeyContent="$( openssl rc4 -d -in "$encFileKeyPath" -iv 0 -K $decUserFileShareKeyHEX )"
   decFileKeyContentHEX="$( echo -n $decFileKeyContent |od -An -tx1 |tr -dc '[:xdigit:]' )"
+  decFileKeyContentHEX=${decFileKeyContentHEX:0:64}
   # --- Get the FileKey ---
 
   # --- Decrypt the file ---

From d25fc4b5c87fa3bb539eb82e1f16c49d1d217af7 Mon Sep 17 00:00:00 2001
From: rjaeckel <robert.jaeckel@itz.uni-halle.de>
Date: Sat, 30 Jan 2016 20:58:28 +0100
Subject: [PATCH 2/5] refactored decryption to use a single file operation,
 increases performance extremely

---
 ocdec.sh | 23 ++++++++++-------------
 1 file changed, 10 insertions(+), 13 deletions(-)

diff --git a/ocdec.sh b/ocdec.sh
index 2f682d0..cd648e2 100755
--- a/ocdec.sh
+++ b/ocdec.sh
@@ -128,19 +128,16 @@ function decryptFile() {
   # --- Get the FileKey ---
 
   # --- Decrypt the file ---
-  # TODO: to figure out how to speed-up the decryption process.
-  #       bottlenecks:
-  #        - awk is running really slow, consuming lot of CPU
-  encFileContentsALL="$(cat "${USER}/$encFilePath")"
-  encFileContentsNOHEAD=$(echo -n "$encFileContentsALL" | sed -r 's/^HBEGIN:.+:HEND-*//')
-  N=0
-  for IV in $(echo -n "$encFileContentsNOHEAD" |grep -E -o '00iv00.{16}xx' |sed -r 's/^00iv00//;s/xx$//'); do
-    N=$[N+1]
-    encFileContentsBASE64=$(echo -n "$encFileContentsNOHEAD" |awk -F '00iv00................xx' -v N=$N '{print $N}')
-    plainFileIVHEX=$(echo -n "$IV" |od -An -tx1 |tr -dc '[:xdigit:]')
-    openssl enc -AES-256-CFB -d -nosalt -base64 -A -K $decFileKeyContentHEX -iv $plainFileIVHEX -in <(echo "$encFileContentsBASE64")
-    #php -r "echo openssl_decrypt('$encFileContentsBASE64', 'AES-256-CFB', '$decFileKeyContent', false, '$IV');"
-  done
+  # OC writes the encrypted file in 8K chunks, each containing it's own iv in the end
+  chunkSize=8192
+  while read -d '' -n $chunkSize CHUNK; do
+    #split chunk into payload an iv string (strip padding from iv)          
+    read payload iv <<<`echo $CHUNK | sed -r 's/(.*)00iv00(.{16})xx/\1 \2/'`
+    # convert base64 iv into hex
+    iv=$(echo -n "$iv" | od -An -tx1 | tr -dc '[:xdigit:]' )
+    # decode chunk
+    openssl enc -AES-256-CFB -d -nosalt -base64 -A -K $decFileKeyContentHEX -iv $iv -in <(echo "$payload")
+    done <<<`sed -r 's/^HBEGIN:.+:HEND-*//' <"$encFilePath"` # pipe the encrypted file without head into the loop
   # --- Decrypt the file ---
 }
 

From 683980933599a4c68b771ee4fac69de8d67d98e6 Mon Sep 17 00:00:00 2001
From: rjaeckel <robert.jaeckel@itz.uni-halle.de>
Date: Sun, 31 Jan 2016 23:17:09 +0100
Subject: [PATCH 3/5] force to read last line of encrypted file

---
 ocdec.sh | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/ocdec.sh b/ocdec.sh
index cd648e2..3ba919c 100755
--- a/ocdec.sh
+++ b/ocdec.sh
@@ -130,7 +130,7 @@ function decryptFile() {
   # --- Decrypt the file ---
   # OC writes the encrypted file in 8K chunks, each containing it's own iv in the end
   chunkSize=8192
-  while read -d '' -n $chunkSize CHUNK; do
+  while read -d '' -n $chunkSize CHUNK || [ -n "$CHUNK" ]; do
     #split chunk into payload an iv string (strip padding from iv)          
     read payload iv <<<`echo $CHUNK | sed -r 's/(.*)00iv00(.{16})xx/\1 \2/'`
     # convert base64 iv into hex

From f5156ef14cd747b0c70524cbe79248985941109e Mon Sep 17 00:00:00 2001
From: rjaeckel <robert.jaeckel@itz.uni-halle.de>
Date: Sun, 31 Jan 2016 23:17:49 +0100
Subject: [PATCH 4/5] missing user parameter in filepath

---
 ocdec.sh | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/ocdec.sh b/ocdec.sh
index 3ba919c..1d67ea7 100755
--- a/ocdec.sh
+++ b/ocdec.sh
@@ -137,7 +137,7 @@ function decryptFile() {
     iv=$(echo -n "$iv" | od -An -tx1 | tr -dc '[:xdigit:]' )
     # decode chunk
     openssl enc -AES-256-CFB -d -nosalt -base64 -A -K $decFileKeyContentHEX -iv $iv -in <(echo "$payload")
-    done <<<`sed -r 's/^HBEGIN:.+:HEND-*//' <"$encFilePath"` # pipe the encrypted file without head into the loop
+    done <<<`sed -r 's/^HBEGIN:.+:HEND-*//' <"${USER}/$encFilePath"` # pipe the encrypted file without head into the loop
   # --- Decrypt the file ---
 }
 

From 2adaf0464f96e33a69c7e598dc87e24d028bd695 Mon Sep 17 00:00:00 2001
From: rjaeckel <robert.jaeckel@itz.uni-halle.de>
Date: Sun, 31 Jan 2016 23:44:19 +0100
Subject: [PATCH 5/5] clear CHUNK variable to avoid infinite loops

---
 ocdec.sh | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/ocdec.sh b/ocdec.sh
index 1d67ea7..863773f 100755
--- a/ocdec.sh
+++ b/ocdec.sh
@@ -130,9 +130,11 @@ function decryptFile() {
   # --- Decrypt the file ---
   # OC writes the encrypted file in 8K chunks, each containing it's own iv in the end
   chunkSize=8192
-  while read -d '' -n $chunkSize CHUNK || [ -n "$CHUNK" ]; do
+  while read -d '' -n $chunkSize CHUNK || [ ! -z "$CHUNK" ]; do
     #split chunk into payload an iv string (strip padding from iv)          
     read payload iv <<<`echo $CHUNK | sed -r 's/(.*)00iv00(.{16})xx/\1 \2/'`
+    CHUNK=
+    #if [ -z $CHUNK ]; then break; fi
     # convert base64 iv into hex
     iv=$(echo -n "$iv" | od -An -tx1 | tr -dc '[:xdigit:]' )
     # decode chunk