I started writing one, but something about the authentication is not working properly, and I thought I'd check to see if anyone had already done this before I try to figure out what is going wrong. Sample code follows, as if there does not already exist a library, I'd be curious if anyone else sees what is wrong with the authentication signature (what I assume is not working), as now it 403's every time.

open Netencoding.Base64

open Cryptokit

open Cryptokit.MAC

open Http_client

let id = "___PUT_YOUR_ID_HERE____"

let key = "__PUT_YOUR_SECRET_KEY_HERE____"

let sign verb content_type date bucket url =

let hash = hmac_sha1 key in

let str_to_sign = verb ^ "\n\n" ^ content_type ^ "\n" ^ date ^ "\n" ^ "/" ^ bucket ^ url in

begin

Printf.printf "---------\n%s\n---------\n" str_to_sign;

"AWS " ^ id ^ ":" ^ encode (hash_string hash str_to_sign)

end

let date () = Netdate.mk_mail_date (Unix.time ())

let text_put_s3 bucket url contents =

let uri = "http://" ^ bucket ^ ".s3.amazonaws.com" ^ url in

let req = new put uri contents in

let head = req#request_header `Base in

let content_type = "text/plain" in

let now = date () in

let pipeline = new pipeline in

begin

pipeline#set_options {pipeline#get_options with verbose_status=true; verbose_request_header=true; verbose_response_header=true;

verbose_request_contents=true; verbose_response_contents=true; verbose_connection=true};

head#set_fields [("Date", now); ("Content-Type", content_type); ("Authentication", sign "PUT" content_type now bucket url)];

req#set_request_header head;

pipeline#add req;

pipeline#run ();

(req#response_status_code, req#response_status_text)

end