unitproc/bkagedecrypt

   1 #!/bin/bash
   2 # Desc: Decrypts files encrypted with age
   3 # Usage: bkagedecrypt -i key.txt file1 file2 ...
   4 # Version: 0.0.1
   5
   6 #==BEGIN Define script parameters==
   7 #===BEGIN Define variables===
   8 declare -g runFlag # If "false", indicates exit required
   9 declare -ag inputFilePaths # Array to store input file paths
  10 declare -Ag appRollCall # Associative array for storing app status
  11 declare -Ag fileRollCall # Associative array for storing file status
  12 declare -Ag dirRollCall # Associative array for storing dir status
  13
  14 timeScriptStartNs="$(date +%Y%m%dT%H%M%S.%N%z)";
  15 dirTemp="/tmp/$timeScriptStartNs"..bkagedecrypt; # will be automatically deleted
  16 #===END Define variables===
  17
  18 #===BEGIN Declare local script functions===
  19 yell() { echo "$0: $*" >&2; } # Yell, Die, Try Three-Fingered Claw technique; # Ref/Attrib: https://stackoverflow.com/a/25515370
  20 die() { yell "$*"; exit 111; }
  21 try() { "$@" || die "cannot $*"; }
  22 vbm() {
  23     # Description: Prints verbose message ("vbm") to stderr if opVerbose is set to "true".
  24     # Usage: vbm "DEBUG :verbose message here"
  25     # Version 0.2.0
  26     # Input: arg1: string
  27     #        vars: opVerbose
  28     # Output: stderr
  29     # Depends: bash 5.0.3, GNU-coreutils 8.30 (echo, date)
  30
  31     if [ "$opVerbose" = "true" ]; then
  32         functionTime="$(date --iso-8601=ns)"; # Save current time in nano seconds.
  33         echo "[$functionTime]:$0:""$*" 1>&2;  # Display argument text.
  34     fi
  35
  36     # End function
  37     return 0; # Function finished.
  38 } # Displays message if opVerbose true
  39 checkapp() {
  40     # Desc: If arg is a command, save result in assoc array 'appRollCall'
  41     # Usage: checkapp arg1 arg2 arg3 ...
  42     # Version: 0.1.1
  43     # Input: global assoc. array 'appRollCall'
  44     # Output: adds/updates key(value) to global assoc array 'appRollCall'
  45     # Depends: bash 5.0.3
  46     local returnState
  47
  48     #===Process Args===
  49     for arg in "$@"; do
  50         if command -v "$arg" 1>/dev/null 2>&1; then # Check if arg is a valid command
  51             appRollCall[$arg]="true";
  52             if ! [ "$returnState" = "false" ]; then returnState="true"; fi;
  53         else
  54             appRollCall[$arg]="false"; returnState="false";
  55         fi;
  56     done;
  57
  58     #===Determine function return code===
  59     if [ "$returnState" = "true" ]; then
  60         return 0;
  61     else
  62         return 1;
  63     fi;
  64 } # Check that app exists
  65 checkfile() {
  66     # Desc: If arg is a file path, save result in assoc array 'fileRollCall'
  67     # Usage: checkfile arg1 arg2 arg3 ...
  68     # Version: 0.1.1
  69     # Input: global assoc. array 'fileRollCall'
  70     # Output: adds/updates key(value) to global assoc array 'fileRollCall';
  71     # Output: returns 0 if app found, 1 otherwise
  72     # Depends: bash 5.0.3
  73     local returnState
  74
  75     #===Process Args===
  76     for arg in "$@"; do
  77         if [ -f "$arg" ]; then
  78             fileRollCall["$arg"]="true";
  79             if ! [ "$returnState" = "false" ]; then returnState="true"; fi;
  80         else
  81             fileRollCall["$arg"]="false"; returnState="false";
  82         fi;
  83     done;
  84
  85     #===Determine function return code===
  86     if [ "$returnState" = "true" ]; then
  87         return 0;
  88     else
  89         return 1;
  90     fi;
  91 } # Check that file exists
  92 checkdir() {
  93     # Desc: If arg is a dir path, save result in assoc array 'dirRollCall'
  94     # Usage: checkdir arg1 arg2 arg3 ...
  95     # Version 0.1.1
  96     # Input: global assoc. array 'dirRollCall'
  97     # Output: adds/updates key(value) to global assoc array 'dirRollCall';
  98     # Output: returns 0 if app found, 1 otherwise
  99     # Depends: Bash 5.0.3
 100     local returnState
 101
 102     #===Process Args===
 103     for arg in "$@"; do
 104         if [ -d "$arg" ]; then
 105             dirRollCall["$arg"]="true";
 106             if ! [ "$returnState" = "false" ]; then returnState="true"; fi
 107         else
 108             dirRollCall["$arg"]="false"; returnState="false";
 109         fi
 110     done
 111
 112     #===Determine function return code===
 113     if [ "$returnState" = "true" ]; then
 114         return 0;
 115     else
 116         return 1;
 117     fi
 118 } # Check that dir exists
 119 displayMissing() {
 120     # Desc: Displays missing apps, files, and dirs
 121     # Usage: displayMissing
 122     # Version 0.1.1
 123     # Input: associative arrays: appRollCall, fileRollCall, dirRollCall
 124     # Output: stderr: messages indicating missing apps, file, or dirs
 125     # Depends: bash 5, checkAppFileDir()
 126     local missingApps value appMissing missingFiles fileMissing
 127     local missingDirs dirMissing
 128
 129     #==BEGIN Display errors==
 130     #===BEGIN Display Missing Apps===
 131     missingApps="Missing apps  :";
 132     #for key in "${!appRollCall[@]}"; do echo "DEBUG:$key => ${appRollCall[$key]}"; done
 133     for key in "${!appRollCall[@]}"; do
 134         value="${appRollCall[$key]}";
 135         if [ "$value" = "false" ]; then
 136             #echo "DEBUG:Missing apps: $key => $value";
 137             missingApps="$missingApps""$key ";
 138             appMissing="true";
 139         fi;
 140     done;
 141     if [ "$appMissing" = "true" ]; then  # Only indicate if an app is missing.
 142         echo "$missingApps" 1>&2;
 143     fi;
 144     unset value;
 145     #===END Display Missing Apps===
 146
 147     #===BEGIN Display Missing Files===
 148     missingFiles="Missing files:";
 149     #for key in "${!fileRollCall[@]}"; do echo "DEBUG:$key => ${fileRollCall[$key]}"; done
 150     for key in "${!fileRollCall[@]}"; do
 151         value="${fileRollCall[$key]}";
 152         if [ "$value" = "false" ]; then
 153             #echo "DEBUG:Missing files: $key => $value";
 154             missingFiles="$missingFiles""$key ";
 155             fileMissing="true";
 156         fi;
 157     done;
 158     if [ "$fileMissing" = "true" ]; then  # Only indicate if an app is missing.
 159         echo "$missingFiles" 1>&2;
 160     fi;
 161     unset value;
 162     #===END Display Missing Files===
 163
 164     #===BEGIN Display Missing Directories===
 165     missingDirs="Missing dirs:";
 166     #for key in "${!dirRollCall[@]}"; do echo "DEBUG:$key => ${dirRollCall[$key]}"; done
 167     for key in "${!dirRollCall[@]}"; do
 168         value="${dirRollCall[$key]}";
 169         if [ "$value" = "false" ]; then
 170             #echo "DEBUG:Missing dirs: $key => $value";
 171             missingDirs="$missingDirs""$key ";
 172             dirMissing="true";
 173         fi;
 174     done;
 175     if [ "$dirMissing" = "true" ]; then  # Only indicate if an dir is missing.
 176         echo "$missingDirs" 1>&2;
 177     fi;
 178     unset value;
 179     #===END Display Missing Directories===
 180
 181     #==END Display errors==
 182 } # Display missing apps, files, dirs
 183 showVersion() {
 184     # Desc: Displays script version and license information.
 185     # Usage: showVersion
 186     # Version: 0.0.1 (modified)
 187     # Input: scriptVersion   var containing version string
 188     # Output: stdout
 189     # Depends: vbm(), yell, GNU-coreutils 8.30
 190
 191     # Initialize function
 192     vbm "DEBUG:showVersion function called."
 193
 194     cat <<'EOF'
 195 bkagedecrypt 0.0.1
 196 Copyright (C) 2021 Steven Baltakatei Sandoval
 197 License GPLv3: GNU GPL version 3
 198 This is free software; you are free to change and redistribute it.
 199 There is NO WARRANTY, to the extent permitted by law.
 200 EOF
 201
 202     # End function
 203     vbm "DEBUG:showVersion function ended."
 204     return 0; # Function finished.
 205 } # Display script version.
 206 processArgs() {
 207     # Desc: Processes arguments provided to script.
 208     # Usage: processArgs "$@"
 209     # Version: 0.0.1 (modified)
 210     # Input: "$@"          (list of arguments provided to the function)
 211     # Output: Sets following variables used by other functions:
 212     #   opVerbose            Indicates verbose mode enable status.  (ex: "true", "false")
 213     #   pathDirOut1          Path to output directory.
 214     #   inputFilePaths       Array containing paths of files to decrypt
 215     # Depends:
 216     #   yell()           Displays messages to stderr.
 217     #   vbm()            Displays messsages to stderr if opVerbose set to "true".
 218     #   showUsage()      Displays usage information about parent script
 219     #   showVersion()    Displays version about parent script
 220     #   checkfile()      Checks if file exists
 221     #   checkdir()       Checks if dir exists
 222     #   dirRollCall      Assoc. array used by checkfile(), checkdir(), checkapp()
 223     #   fileRollCall     Assoc. array used by checkfile(), checkdir(), checkapp()
 224     #   appRollCall      Assoc. array used by checkfile(), checkdir(), checkapp()
 225     # External dependencies: bash (5.0.3), echo
 226     # Ref./Attrib.:
 227     #  [1]: Marco Aurelio (2014-05-08). "echo that outputs to stderr". https://stackoverflow.com/a/23550347
 228     vbm "STATUS:start processArgs()";
 229
 230     # Perform work
 231     while [ ! $# -eq 0 ]; do   # While number of arguments ($#) is not (!) equal to (-eq) zero (0).
 232         #vbm "DEBUG:Starting processArgs while loop." # Debug stderr message. See [1].
 233         #vbm "DEBUG:Provided arguments are:""$*"      # Debug stderr message. See [1].
 234         case "$1" in
 235             -h | --help) showUsage; exit 1;; # Display usage.
 236             --version) showVersion; exit 1;; # Show version
 237             -v | --verbose) # Enable verbose mode. See [1].
 238                 opVerbose="true";
 239                 vbm "DEBUG:Verbose mode enabled.";;
 240             -i | --identity) # Define identity file
 241                 pathFileIdentity="$2";
 242                 shift;;
 243             -O | --output-dir) # Define output directory path
 244                 pathDirOut1="$2";
 245                 vbm "DEBUG:Setting pathDirOut1 to:$pathDirOut1";
 246                 shift;;
 247             *) inputFilePaths+=("$1"); # Add to inputArgs array
 248                vbm "DEBUG:Added to inputFilePaths array:$1";
 249         esac;
 250         shift;
 251     done;
 252
 253     # If pathDirOut1 not set, set as default
 254     if [[ -z $pathDirOut1 ]]; then
 255         pathDirOut1="$(pwd)"; # Fall back to using current working directory
 256         vbm "DEBUG:pathDirOut1 not set. Setting to default:$pathDirOut1";
 257     fi;
 258
 259     # Exit if pathFileIdentity not set
 260     if [[ -z $pathFileIdentity ]]; then
 261         showUsage;
 262         die "ERROR:not set:pathFileIdentity:$pathFileIdentity";
 263     fi;
 264
 265     # Check apps, dirs
 266     if ! checkapp age tar gunzip; then runFlag="false"; fi;
 267     if ! checkdir "$pathDirOut1"; then runFlag="false"; fi;
 268     # Check files
 269     ## Check identity file (required)
 270     if ! checkfile "$pathFileIdentity"; then runFlag="false"; fi;
 271     ## Check inputFilePaths
 272     if [[ ${#inputFilePaths[@]} -eq 0 ]]; then
 273         vbm "DEBUG:ERROR:inputFilePaths array empty:'${inputFilePaths[*]}'";
 274         runFlag="false"; fi;
 275     for path in "${inputFilePaths[@]}"; do
 276         vbm "DEBUG:Checking if file path $path exists.";
 277         if ! checkfile "$path"; then
 278             runFlag="false";
 279             vbm "DEBUG:ERROR:File does not exist:$path"; fi;
 280     done;
 281
 282     # On error, display missing elements, exit.
 283     if [[ $runFlag == "false" ]]; then
 284         displayMissing;
 285         showUsage;
 286         die "ERROR:Input argument requirements unsatisfied. Exiting.";
 287     else
 288         vbm "STATUS:Input argument requirements satisfied.";
 289     fi;
 290
 291     # End function
 292     vbm "STATUS:end processArgs()";
 293     return  0; # Function finished.
 294 } # Evaluate script options from positional arguments (ex: $1, $2, $3, etc.).
 295 showUsage() {
 296     # Desc: Display script usage information
 297     # Usage: showUsage
 298     # Version 0.0.1 (modified)
 299     # Input: none
 300     # Output: stdout
 301     # Depends: GNU-coreutils 8.30 (cat)
 302     cat <<'EOF'
 303     NAME:
 304         bkagedecrypt - decrypt age-encrypted files
 305     USAGE:
 306         bkagedecrypt [ options ] [FILE...]
 307
 308     DESCRIPTION:
 309         Decrypt FILE(s) using `age` v1.0.0-rc.3. See:
 310           https://github.com/FiloSottile/age
 311
 312         FILE(s) must have the following file name extensions and properties:
 313             .gz.age.tar,    File is a tar archive containing one or more
 314                               subfiles within. Each subfile contains an
 315                               age-encrypted, gzip-compressed plaintext file.
 316             .gz.age,        File is an age-encrypted gzip-compressed plaintext
 317                               file.
 318             .age,           File is an age-encrypted plaintext file.
 319
 320         Decryption via password is not supported.
 321
 322     OPTIONS:
 323         -i, --identity KEY
 324                 Path of private key file passed to `age`.
 325         -O, --output-dir
 326                 Define output directory path. (Default: current working dir)
 327         -h, --help
 328                 Display help information.
 329         --version
 330                 Display script version.
 331         -v, --verbose
 332                 Display debugging info.
 333
 334     EXAMPLE:
 335       $ bkagedecrypt -i key.txt foo.gz.age.tar
 336       $ bkagedecrypt -i key.txt foo.gz.age.tar bar.gz.age baz.age
 337       $ bkagedecrypt -i ky.txt -O ../ foo.gz.age.tar bar.gz.age baz.age
 338
 339 EOF
 340 } # Display information on how to use this script.
 341 extractGzAgeTar() {
 342     # Desc: Extracts contents from .gz.age.tar
 343     # Usage: extractGzAgeTar arg1
 344     # Input: - arg1: path to file
 345     #        - pathFileIdentity: path to age identity file (for decryption)
 346     #        - pathDirOut1: path to output dir
 347     # Output: file writes $pathDirOut1
 348     # Depends: age v1.0.0-rpc3, GNU tar v1.30
 349     vbm "STATUS:start extractGzAgeTar()";
 350     vbm "args:$*";
 351     vbm "pathFileIdentity:$pathFileIdentity";
 352     vbm "pathDirOut1:$pathDirOut1";
 353     local file
 354     local -a fileNameList
 355
 356     # Get filename from path
 357     file="$(basename "$1")";
 358
 359     # Get list of files from tar
 360     while read -r line; do
 361         fileNameList+=("$line");
 362         vbm "Adding to fileNameList:$line";
 363     done < <(try tar --list -f "$1");
 364     vbm "STATUS:fileNameList:${fileNameList[*]}";
 365
 366     # Extract .gz.age files from tar to temporary dir
 367     vbm "Extracting files from '$1' to '$dirTemp'";
 368     try tar -xf "$1" -C "$dirTemp";
 369
 370     # Decrypt and decompress each .gz.age file to $pathDirOut1
 371     for fileName in "${fileNameList[@]}"; do
 372         if [[ $fileName =~ .gz.age$ ]]; then
 373             ## Decrypt and decompress files ending in .gz.age
 374             vbm "DEBUG:Decrypting file:$dirTemp/$fileName";
 375             try age -i "$pathFileIdentity" -d "$dirTemp"/"$fileName" | try gunzip > "$pathDirOut1"/"${fileName%.gz.age}";
 376         else
 377             ## Copy other files as-is
 378             try cp "$dirTemp"/"$fileName" "$pathDirOut1"/"$fileName";
 379         fi;
 380     done;
 381
 382     vbm "STATUS:end extractGzAgeTar()";
 383 } # Extracts contents from .gz.age.tar
 384 extractGzAge() {
 385     # Desc: Extracts contents from .gz.age
 386     # Usage: extractGzAge arg1
 387     # Input: - arg1: path to file
 388     #        - pathFileIdentity: path to age identity file (for decryption)
 389     #        - pathDirOut1: path to output dir
 390     # Output: file writes $pathDirOut1
 391     # Depends: age v1.0.0-rpc3
 392     vbm "STATUS:start extractGzAge()";
 393     vbm "args:$*";
 394     vbm "pathFileIdentity:$pathFileIdentity";
 395     vbm "pathDirOut1:$pathDirOut1";
 396     local file
 397
 398     # Get filename from path
 399     file="$(basename "$1")";
 400
 401     # Decrypt and decompress to $pathDirOut1
 402     try age -i "$pathFileIdentity" -d "$1" | try gunzip > "$pathDirOut1"/"${file%.gz.age}";
 403     :
 404     vbm "STATUS:end extractGzAge()";
 405 } # Extracts contents from .gz.age
 406 extractAge() {
 407     # Desc: Extracts contents from .age
 408     # Usage: extractAge arg1
 409     # Input: - arg1: path to file
 410     #        - pathFileIdentity: path to age identity file (for decryption)
 411     #        - pathDirOut1: path to output dir
 412     # Output: file writes $pathDirOut1
 413     # Depends: age v1.0.0-rpc3
 414     vbm "STATUS:start extractAge()";
 415     vbm "args:$*";
 416     vbm "pathFileIdentity:$pathFileIdentity";
 417     vbm "pathDirOut1:$pathDirOut1";
 418     local file
 419
 420     # Get filename from path
 421     file="$(basename "$1")";
 422
 423     # Decrypt to $pathDirOut1
 424     try age -i "$pathFileIdentity" -d "$1" > "$pathDirOut1"/"${file%.age}";
 425
 426     vbm "STATUS:end extractAge()";
 427 } # Extracts contents from .age
 428
 429 main() {
 430     vbm "STATUS:start main()";
 431     # Process options
 432     ## Sets vars: - pathDirOut1 (from -O, --output-dir option)
 433     ##            - opVerbose (from -v, --verbose option)
 434     ##            - pathFileIdentity (from -i, --identity option)
 435     processArgs "$@";
 436
 437     # Create temporary working dir
 438     try mkdir "$dirTemp";
 439
 440     # Verify input args
 441     for arg in "${inputFilePaths[@]}"; do
 442         vbm "DEBUG:input file path is:$arg";
 443         ## Ends in .gz.age.tar?
 444         if [[ $arg =~ .gz.age.tar$ ]]; then
 445             vbm "DEBUG:$arg ends in .gz.age.tar";
 446             vbm "DEBUG:$arg is a valid file extension";
 447             : # do nothing
 448         ## Ends in .gz.age?
 449         elif [[ $arg =~ .gz.age$ ]]; then
 450             vbm "DEBUG:$arg ends in .gz.age";
 451             vbm "DEBUG:$arg is a valid file extension";
 452         ## Ends in .age?
 453         elif [[ $arg =~ .age$ ]]; then
 454             vbm "DEBUG:$arg ends in .age";
 455             vbm "DEBUG:$arg is a valid file extension";
 456         else
 457             showUsage;
 458             die "ERROR:Invalid file extension detected.";
 459         fi;
 460     done;
 461
 462     # Work on each file
 463     for file in "${inputFilePaths[@]}"; do
 464         vbm "DEBUG:input file path is:$arg";
 465         vbm "DEBUG:file is:$file";
 466         ## Ends in .gz.age.tar?
 467         if [[ $file =~ .gz.age.tar$ ]]; then
 468             vbm "DEBUG:Beginning extraction of file(s) from $file";
 469             extractGzAgeTar "$file";
 470         ## Ends in .gz.age?
 471         elif [[ $file =~ .gz.age$ ]]; then
 472             vbm "DEBUG:Beginning extraction of file from $file";
 473             extractGzAge "$file";
 474         ## Ends in .age?
 475         elif [[ $file =~ .age$ ]]; then
 476             vbm "DEBUG:Beginning extraction of file from $file";
 477             extractAge "$file";
 478         else
 479             vbm "DEBUG:Invalid file extension detected:$file"
 480             showUsage;
 481             die "Exiting.";
 482         fi;
 483     done;
 484
 485     # Remove temporary directory
 486     try rm -rf "$dirTemp";
 487     vbm "STATUS:end main()";
 488 }
 489 #===END Declare local script functions===
 490 #==END Define script parameters==
 491
 492 # Run program
 493 main "$@";
 494
 495 # Author: Steven Baltakatei Sandoval
 496 # License: GPLv3+