Amazon S3 is the online storage service offered by Amazon Web Services (AWS). Its interface (S3 REST API) is public and has become the de-facto standard for cloud storage. To be able to use Amazon S3 service, you first need to sign up for an AWS account. The account is free and you will pay only for the amount of storage and traffic that you actually use.

For more information click on the following link :  http://aws.amazon.com/s3/faqs/

DragonDisk is an application that allows you to manage files stored on a service compatible with Amazon S3.

DragonDisk is a "freeware". It is distributed free of charge for any private and corporate use. It is provided "as is" without warranty of any kind. You may download it and install it on as many machines as you wish, copy it for other people; but you may not incorporate DragonDisk into any "commercial" product or service. 

DragonDisk is not really a backup software but is a "file manager". But you can use it as a basic backup solution thanks to its synchronization and encryption features.

Google provides two different storage services: Google Cloud Storage, and Google Drive.

DragonDisk is compatible with Google Cloud Storage but not with Google Drive. Google Drive does not offer an S3 compatible API, and Google Cloud Storage is not currently integrated with Google Docs.

DragonDisk is still in development and there is no documentation available yet. But if you're familiar with the Amazon S3 AWS Console, you will have no troubles using DragonDisk. A Quick Start Guide is available to help you get started.

For installing the package from a terminal, perform the following steps :

 
Ubuntu 11.10 and later require an old version of libssl to be installed :
sudo apt-get install libssl0.9.8

Ubuntu 32-bit :

Download the native package and install like this :
wget http://download.dragondisk.com/dragondisk_1.0.5-0ubuntu_i386.deb
sudo apt-get install libqt4-dbus libqt4-network libqt4-xml libqtcore4 libqtgui4
sudo dpkg -i dragondisk_1.0.5-0ubuntu_i386.deb

Ubuntu  64-bit ( >= 10.04 ) :

Download the native package and install like this :
wget http://download.dragondisk.com/dragondisk_1.0.5-0ubuntu_amd64.deb
sudo apt-get install libqt4-dbus libqt4-network libqt4-xml libqtcore4 libqtgui4
sudo dpkg -i dragondisk_1.0.5-0ubuntu_amd64.deb

To start the Application, enter :
dragondisk

You can also start it from the KDE/Gnome GUI menu  ( Applications -> Internet -> DragonDisk )

This feature is not available in DragonDisk. But you can schedule a backup using the command-line tool.

DragonDisk uses the OpenSSL library and produces the same result as OpenSSL.
The encryption is directly equivalent to these commands :

# encrypt / decrypt using 256-bit AES in CBC mode
openssl enc -md sha1  -aes-256-cbc -in clearfile -out cryptedfile -pass pass:myPassword
openssl enc -md sha1  -d -aes-256-cbc -in cryptedfile -out clearfile -pass pass:myPassword

# encrypt / decrypt using Blowfish in CBC mode
openssl enc -md sha1  -bf-cbc -in clearfile -out cryptedfile -pass pass:myPassword
openssl enc -md sha1 -d -bf-cbc -in cryptedfile -out clearfile -pass pass:myPassword

# encrypt /decrypt using three key triple DES EDE in CBC mode
openssl enc -md sha1 -des-ede3-cbc -in clearfile -out cryptedfile -pass pass:myPassword
openssl enc -md sha1 -d -des-ede3-cbc -in cryptedfile -out clearfile -pass pass:myPassword

Here is a sample script for Linux...

# export http_proxy=http://username:password@host:port/
export DGTOOLS_ACCESS_KEY=myAccessKey
export DGTOOLS_SECRET_KEY=mySecretKey
export DGTOOLS_ENCRYPTION_PASSWORD=myPassword
export DGTOOLS_DECRYPTION_PASSWORD_0=myPassword
export DGTOOLS_DECRYPTION_PASSWORD_1=myOldPassword
#
#
# Local to Google cloud storage
# dgsync -z -e aes-256-cbc /home/tony/documents/ gs://mybucket/documents/
# Google Cloud storage to local
# dgsync gs://mybucket/documents/ /home/tony/documents/
# Local to Connectria
# dgsync -z -e aes-256-cbc --endpoint rs2.connectria.com /home/tony/documents/ s3://mybucket/documents/
# Connectria to local
# dgsync --endpoint rs2.connectria.com s3://mybucket/documents/ /home/tony/documents/
# Local to Amazon S3
dgsync -z -e aes-256-cbc /home/tony/documents/ s3://mybucket/documents/
# Amazon S3 to local
# dgsync s3://mybucket/documents/ /home/tony/documents/

   ... and Windows

REM SET http_proxy=http://username:password@host:port/
SET DGTOOLS_ACCESS_KEY=myAccessKey
SET DGTOOLS_SECRET_KEY=mySecretKey
SET DGTOOLS_ENCRYPTION_PASSWORD=myPassword
SET DGTOOLS_DECRYPTION_PASSWORD_0=myPassword
SET DGTOOLS_DECRYPTION_PASSWORD_1=myOldPassword
REM Local to Google cloud storage
REM dgsync.exe -z -e aes-256-cbc "C:/my folder/" "gs://mybucket/my folder/"
REM Google Cloud storage to local
REM dgsync.exe "gs://mybucket/my folder/" "C:/my folder/"
REM Local to Connectria
REM dgsync.exe -z -e aes-256-cbc --endpoint rs2.connectria.com "C:/my folder/" "s3://mybucket/my folder/"
REM Connectria to local
REM dgsync.exe --endpoint rs2.connectria.com "s3://mybucket/my folder/" "C:/my folder/"
REM Local to Amazon S3
dgsync.exe -z -e aes-256-cbc "C:/my folder/" "s3://mybucket/my folder/"
REM Amazon S3 to local
REM dgsync.exe "s3://mybucket/my folder/" "C:/my folder/"

The following options are available:

-v   --verbose                    Verbose
-V   --version                    Display the version number
-h   --help                       Display a help screen and quit
-D   --debug                      Debug mode
-t   --threads                    Number of threads (default: 4)
-A   --access-key ACCESS_KEY      Access Key ID
-S   --secret-key SECRET_KEY      Secret Key
     --ssl                        Enable SSL/HTTPS
     --endpoint                   Define the endpoint of the service
-h   --hidden-files               Include hidden files.
-s   --system-files               Include system files.
-l   --symbolic-links             Do not ignore symbolic links.
     --keep-new                   If a file exists in the source and target
                                  folders, do not replace the target file if it is
                                  newer than the source file.
     --dont-delete                If a file exists in the target folder but not the
                                  source, do not delete the target file.
     --dont-add                   If a file exists in the source folder but not the
                                  target, do not copy the source file.
     --dont-replace               If a file exists in the source and target
                                  folders, do not replace the target file.

Filters :
     --include-cs-filename GLOB   Include files with names matching GLOB.
                                  Matching is case-sensitive.
     --include-ci-filename GLOB   Include files with names matching GLOB.
                                  Matching is case-insensitive.
     --exclude-cs-filename GLOB   Exclude files with names matching GLOB.
                                  Matching is case-sensitive.
     --exclude-ci-filename GLOB   Exclude files with names matching GLOB.
                                  Matching is case-insensitive.

                                  A file is synchronized only if it matches at
                                  least one file inclusion filter and does not
                                  match any file exclusion filter. If no inclusion
                                  filters are specified, all files are included.

Storage :
     --rrs                        Use Reduced Redundancy Storage (Amazon S3 Only)

Compression :
-z   --compress                   Enable compression

Client side encryption :
-e   --encrypt CIPHER             Enable client side encryption.

                                   Supported OpenSSL ciphers :
                                   aes-256-cbc    256 bit AES in CBC mode
                                   aes-192-cbc    192 bit AES in CBC mode
                                   aes-128-cbc    128 bit AES in CBC mode
                                   aes-256-cfb    256 bit AES in 128 bit CFB mode
                                   aes-192-cfb    192 bit AES in 128 bit CFB mode
                                   aes-128-cfb    128 bit AES in 128 bit CFB mode
                                   aes-256-cfb1   256 bit AES in 1 bit CFB mode
                                   aes-192-cfb1   192 bit AES in 1 bit CFB mode
                                   aes-128-cfb1   128 bit AES in 1 bit CFB mode
                                   aes-256-cfb8   256 bit AES in 8 bit CFB mode
                                   aes-192-cfb8   192 bit AES in 8 bit CFB mode
                                   aes-128-cfb8   128 bit AES in 8 bit CFB mode
                                   aes-256-ofb    256 bit AES in OFB mode
                                   aes-192-ofb    192 bit AES in OFB mode
                                   aes-128-ofb    28 bit AES in OFB mode
                                   bf-cbc         Blowfish in CBC mode
                                   bf-cfb         Blowfish in CFB mode
                                   bf-ofb         Blowfish in OFB mode
                                   des-ede3-cbc   Three key triple DES EDE
                                                  in CBC mode
                                   des-ede3-cfb   Three key triple DES EDE
                                                  in CFB mode
                                   des-ede3-ofb   Three key triple DES EDE
                                                  in OFB mode

     --nosalt                     Don't use a salt in the key derivation routines.
     --encryption-password PWD    Use PWD to encrypt files.
     --decryption-password PWD    Use PWD to decrypt files. You may set this option
                                  several times.

Server side encryption :
     --server-side-encryption     Enable Server Side Encryption
                                  (Amazon S3 Only)