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
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.
These settings can be passed as environment variables or fed to the
server on STDIN in colon separated format. Both the new and old forms
of the AWS credential environment variables are supported.
# AWS Settings
AWS_ACCESS_KEY = account access key
AWS_ACCESS_KEY_ID = account access key
AWS_SECRET_KEY = secret
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:
However, SSSP skips over lines that contain quotes ("') or that appear
to require shell interpolation for their correct interpolation (lines
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 http://sssp.io/p/a/t/h # Signed for the default time (10s).
GET http://sssp.io/p/a/t/h?t=n # Signed for n seconds.
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-
URLs are divided syntactically in to listings and items. A URL ending
with a slash is always a listing.
GET http://sssp.io/dist # Signed redirect to an object called dist.
GET http://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.)
# Retrieval with @hi and @lo.
GET http://sssp.io/dist/x/@hi -307-> http://sssp.io/dist/x/x-0.2.11.tgz
GET http://sssp.io/dist/x/@lo -307-> http://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 http://sssp.io/dist/x/@lo2 -200-> dist/x/x-0.1.1.tgz
Counts are the natural numbers starting at 0. The wildcard @* refers to
"all the items".
A counted wildcard, like @hi2, can be suffixed with a tilde to form its
complement -- so @hi2~ is everything but the highest two items. This
can be useful for bulk deletion of old/new things.
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.
Keys sorted ASCIIbetically, in the C locale (sorted purely by
The default sort, which is semantic version sort.
@*, @*.semver, @*.ascii
All the items, in the default order (semantic version) or in
a specified order.
ASCII sort can be substantially more performant than semantic version
sort, because S3 returns data in ASCII order and thus no real sorting
# Start web application.
sssp < conf
# Start web application with configuration provided by the environment.
Listing results should really be URLs. The time to sign should really
be configurable; or at least settable with a query parameter.