Provided by: aespipe_2.3e-2_i386 bug

NAME

       aespipe - AES encrypting or decrypting pipe

SYNOPSIS

       aespipe [options] <inputfile >outputfile

DESCRIPTION

       aespipe reads from standard input and writes to standard output. It can
       be used to create and restore encrypted tar or cpio archives. It can be
       used  to encrypt and decrypt loop-AES compatible encrypted disk images.

       The AES cipher is used in CBC (cipher block  chaining)  mode.  Data  is
       encrypted and decrypted in 512 byte chains.  aespipe supports three key
       setup modes; single-key, multi-key-v2 and multi-key-v3  modes.  Single-
       key  mode  uses simple sector IV and one AES key to encrypt and decrypt
       all data sectors. Multi-key-v2 mode uses cryptographically more  secure
       MD5  IV  and 64 different AES keys to encrypt and decrypt data sectors.
       In multi-key mode first key is used for first sector,  second  key  for
       second  sector,  and so on. Multi-key-v3 is same as multi-key-v2 except
       is uses one extra 65th key as additional input to MD5  IV  computation.
       See  -K  option  for  more information about how to enable multi-key-v3
       mode.

       Recommended key setup mode is  multi-key-v3,  which  is  based  on  gpg
       encrypted  key files. In this mode, the passphrase is protected against
       optimized dictionary attacks via salting  and  key  iteration  of  gpg.
       Passphrase length should be 20 characters or more.

       Single-key  mode preserves input size at 16 byte granularity. Multi-key
       mode preserves input size at 512 byte granularity. If input size is not
       multiple  of  16  or 512 bytes, input data is padded with null bytes so
       that both input and output sizes are multiples of 16 or 512 bytes.

OPTIONS

       -A gpgAgentSocket
              Read passphrase of gpg encrypted key file from gpg-agent instead
              of the terminal. aespipe runs gpg to decrypt a key file, and gpg
              talks to gpg-agent using gpgAgentSocket. Usually this data is in
              GPG_AGENT_INFO  environment  variable.  The  environment that is
              passed to  gpg  is  very  minimal.   Normally  gpg  passes  some
              environment  variables  to  gpg-agent,  but  in this case, there
              aren’t any. For best results, you may  want  to  configure  gpg-
              agent  so that it "keeps" and uses its own environment. Defining
              "keep-tty",    "keep-display"    and    "pinentry-program"    in
              $HOME/.gnupg/gpg-agent.conf  configuration file is a good start.

       -C itercountk
              Runs hashed passphrase through itercountk thousand iterations of
              AES-256  before using it for data encryption. This consumes lots
              of CPU cycles at program  start  time  but  not  thereafter.  In
              combination  with  passphrase  seed  this  slows down dictionary
              attacks. Iteration is not done in multi-key mode.

       -d     Decrypt data. If this option is not specified, default operation
              is to encrypt data.

       -e encryption
              Following  encryption  types  are  recognized: AES128 (default),
              AES192 and AES256. Encryption type names are  case  insensitive.
              AES128   defaults  to  using  SHA-256  passphrase  hash,  AES192
              defaults to using SHA-384 passphrase hash, and  AES256  defaults
              to using SHA-512 passphrase hash.

       -G gpghome
              Set   gpg   home   directory   to  gpghome,  so  that  gpg  uses
              public/private keys on gpghome directory. This is only used when
              gpgkey  file needs to be decrypted using public/private keys. If
              gpgkey  file  is   encrypted   with   symmetric   cipher   only,
              public/private  keys  are  not  required  and this option has no
              effect.

       -H phash
              Uses phash function to hash passphrase. Available hash functions
              are  sha256,  sha384, sha512 and rmd160. unhashed1 and unhashed2
              functions  also  exist  for  compatibility  with  some  obsolete
              implementations. Hash type names are case insensitive.

       -K gpgkey
              Passphrase  is  piped to gpg so that gpg can decrypt file gpgkey
              which contains the real keys that are used to encrypt  data.  If
              decryption  requires  public/private  keys  and  gpghome  is not
              specified, all users use their own gpg  public/private  keys  to
              decrypt  gpgkey.  Decrypted  gpgkey should contain 1 or 64 or 65
              keys, each key at least 20 characters and separated by  newline.
              If  decrypted gpgkey contains 64 or 65 keys, then aespipe is put
              to multi-key mode. 65th key, if present, is used  as  additional
              input to MD5 IV computation.

       -O sectornumber
              Set  IV  offset  in  512  byte  units.  Default is zero. Data is
              encrypted in 512 byte CBC chains and each 512 byte chain  starts
              with  IV  whose  computation  depends on offset within the data.
              This option can be used to start  encryption  or  decryption  in
              middle of some existing encrypted disk image.

       -p fdnumber
              Read the passphrase from file descriptor fdnumber instead of the
              terminal. If -K option is not being used (no gpg key file), then
              aespipe  attempts  to  read  65  keys from passwdfd, each key at
              least  20  characters  and  separated  by  newline.  If  aespipe
              successfully  reads 64 or 65 keys, then aespipe is put to multi-
              key mode. If aespipe encounters end-of-file before 64  keys  are
              read, then only first key is used in single-key mode.

       -P cleartextkey
              Read  the  passphrase  from  file  cleartextkey  instead  of the
              terminal. If -K option is not being used (no gpg key file), then
              aespipe  attempts to read 65 keys from cleartextkey, each key at
              least  20  characters  and  separated  by  newline.  If  aespipe
              successfully  reads 64 or 65 keys, then aespipe is put to multi-
              key mode. If aespipe encounters end-of-file before 64  keys  are
              read, then only first key is used in single-key mode. If both -p
              and -P options are used, then -p option takes precedence.  These
              are equivalent:

              aespipe -p3 -K foo.gpg -e AES128 ...   3<someFileName

              aespipe -P someFileName -K foo.gpg -e AES128 ...

              In  first line of above example, in addition to normal open file
              descriptors (0==stdin 1==stdout 2==stderr), shell opens the file
              and  passes  open file descriptor to started aespipe program. In
              second line of above example, aespipe opens the file itself.

       -q     Be quiet and don’t complain about write errors.

       -S pseed
              Sets encryption passphrase seed pseed which is appended to  user
              supplied  passphrase before hashing. Using different seeds makes
              dictionary attacks slower but does  not  prevent  them  if  user
              supplied passphrase is guessable.  Seed is not used in multi-key
              mode.

       -T     Asks passphrase twice instead of just once.

       -w number
              Wait number seconds before asking passphrase.

RETURN VALUE

       aespipe returns 0 on success, nonzero on failure.

AVAILABILITY

       Source is available from http://loop-aes.sourceforge.net/

AUTHORS

       Jari Ruusu