SYNOPSIS
       sssp web?

DESCRIPTION
       SSSP is an HTTP proxy for S3 that can generate short-lived, signed URLs
       for stored objects. By providing a server separate from S3 that can  be
       placed  behind an authenticating proxy or firewall, SSSP allows a vari-
       ety of common security mechanisms to be used  to  limit  access  to  S3
       objects over HTTP while taking advantage of S3's considerable bandwidth
       and parallelism.

       Use-cases for SSSP include:

          o sharing of large files within an organization,

          o media service for public facing web applications,

          o distribution of internal software.

       SSSP supports configuration via environment variables or STDIN.

CONFIGURATION
       These settings can be passed as environment variables  or  fed  to  the
       server on STDIN in colon separated format.

       # AWS Settings
       AWS_ACCESS_KEY_ID           = account access key
       AWS_SECRET_ACCESS_KEY       = secret
       AWS_REGION                  = eu-west-1, classic, us-east-1, ...

       # Storage settings
       SSSP_BUCKET                 = DNS friendly bucket name

       # Server settings
       SSSP_CONN                   = <ip>:<port> pair
       PORT                        = port to connect to, on localhost

       SSSP  is  fairly  liberal when parsing STDIN. In fact, Bourne shell .rc
       files, like the follow example, are parsed without error:

       export SSSP_BUCKET=dist
       export SSSP_CONN=*:6000

       However, SSSP does not parse shell quotes (which  one  is  unlikely  to
       need for the kinds of values involved, given their rigid formats).

REST INTERFACE
       URLs  in  SSSP point to one of two objects: an item or a listing. Items
       correspond to S3 objects; a GET retrieves  a  signed  redirect  to  the
       object.   Listings  are  a  sequence of URLs, in ascending order; a GET
       retrieves the listing as a plaintext document, one URL per line.

       GET https://sssp.io/p/a/t/h         # Signed for the default time (10s).

       A PUT to an item sets the item's content. DELETEs can  be  singular  or
       plural.  A  plural DELETE removes only the objects generated by a list-
       ing.

       URLs are divided syntactically in to listings and items. A  URL  ending
       with a slash is always a listing.

       GET https://sssp.io/dist   # Signed redirect to an object called dist.
       GET https://sssp.io/dist/  # Listing of items below the key `dist'.

       To  make  it  easier to work with versioned or timestamped assets, SSSP
       supports the @hi and @lo meta-paths. These correspond to the names that
       sort  highest  and  lowest  according  to  semantic version sort, where
       non-digit chars serve to delimit arrays of numbers. For common forms of
       dates, these have the same effect as ASCII sort. (ASCII sort may speci-
       fied, as well; please the section WILDCARDS, below.)

       GET https://sssp.io/dist/x/x-0.1.1.tgz
       GET https://sssp.io/dist/x/x-0.1.4.tgz
       GET https://sssp.io/dist/x/x-0.2.11.tgz
       GET https://sssp.io/dist/x/x-0.2.9.tgz

       # Retrieval with @hi and @lo.
       GET https://sssp.io/dist/x/@hi  -307->  https://sssp.io/dist/x/x-0.2.11.tgz
       GET https://sssp.io/dist/x/@lo  -307->  https://sssp.io/dist/x/x-0.1.1.tgz

       Wildcards @hi and @lo used together with a count specify  a  set  wild-
       card; the result is a listing:

       GET https://sssp.io/dist/x/@lo2  -200->  dist/x/x-0.1.1.tgz
                                               dist/x/x-0.1.4.tgz

       Counts are the natural numbers starting at 0.

       A  counted  wildcard,  like  @hi2, can be suffixed with a tilde to form
       it's complement -- so @hi2~ is everything but the  highest  two  items.
       This can be useful for bulk deletion of old/new things.

WILDCARDS
          @hi.semver, @lo.semver
                 Key  with  highest or lowest version, according to a liberal-
                 ized form of "semantic versioning", where version  components
                 are delimited by any non-digit characters.

          @hi.ascii, @lo.ascii
                 Keys sorted ASCIIbetically, in the C locale (sorted purely by
                 byte value).

          @hi, @lo
                 The default sort, which is semantic version sort.

EXAMPLES
       # Start web application.
       sssp < conf

       # Start web application with some configuration provided by the environment.
       export AWS_ACCESS_KEY_ID=...
       export AWS_SECRET_ACCESS_KEY=...
       sssp <<CONF
       SSSP_BUCKET: dist
       CONF

BUGS
       Listing results should really be URLs. The time to sign  should  really
       be configurable; or at least settable with a query parameter.