Decrypt Signal message DB

Decrypt Signal message DB & conver it to a valid JSON

Posted on One min read

All but the last step are based on this answer on unix.stackexchange: https://unix.stackexchange.com/questions/505008/signal-desktop-how-to-export-messages

Locate db.sqlite & db key

Find Signal DB one of these locations:

  • ~/.config/Signal/sql/db.sqlite
  • ~/.var/app/org.signal.Signal/config/Signal/sql/db.sqlite

The decryption key is in config.json which is located in one thes location:

  • ~/.config/Signal/config.json
  • ~/.var/app/org.signal.Signal/config/Signal/config.json

Compile sqlcipher

As of writing, you’ll need sqlcipher v3.30 or newer to decrypt Signal’s message DB.

Get it from https://github.com/sqlcipher/sqlcipher

Then compile it with dynamic linking:

./configure \
    --enable-tempstore=yes \
    CFLAGS="-DSQLITE_HAS_CODEC" \
    LDFLAGS="-lcrypto"
make

Decrypt db.sqlite 

/path/to/sqlcipher \
    -list \
    -noheader \
    "db.sqlite" \
    "PRAGMA key = \"x'"${SIGNAL_KEY}"'\";select json from messages;" > clear_text_msgs;

Turn it into a valid JSON file

The file with clear text messages is not a valid JSON, thus we need to:

  1. Remove first line, that contains word “ok”
  2. Add a comma at the end of every line
  3. Add leading [
  4. Add trailing ]
tail -n +2 clear_text_msgs > without_ok
sed '$!s/$/,/' without_ok > with_commas
sed '1 s/^/[\n/' with_commas > with_leading_bracket
echo "]" >> with_leading_bracket
rm without_ok
rm with_commas
mv with_leading_bracket valid.json