OCaml 中的 HMAC-SHA1 签名?

Question

我正在尝试向Twitter API发出请求，他们要求我签署我的请求。最后一部分需要通过HMAC-SHA1哈希算法进行签名。有没有简单的方法可以得到它？

Answer 1

Hannes伸出手给了我答案(用下面的ReasonML语法，而不是OCaml(：

Nocrypto.Hash.SHA1.hmac key::(Cstruct.of_string signingKey) (Cstruct.of_string output) |> Cstruct.to_string

有了这个，这里有一个从 Twitter API 文档翻译而来的签名函数(参数和值也取自该页面，因此输出可以验证为正确(：

let signRequest clientId clientSecret method uri params :string => {
let tmp = params |> List.sort (fun (a, _) (b, _) => compare a b);
let collectedParamsString =
List.map
(
fun (header: string, values: list string) => {
let nextStr =
List.fold_left
(
fun innerAcc value => {
let nextItem =
/* Using `Userinfo here is weird, but it's the only component I could get to properly percent-encode things in the same way Twitter expects it */
Uri.pct_encode component::`Query_key header ^
"=" ^ Uri.pct_encode component::`Userinfo value;
let final = innerAcc @ [nextItem];
print_endline (value ^ " => " ^ String.concat "&" final);
final
}
)
[]
values |>
String.concat "&";
nextStr
}
)
tmp |>
String.concat "&";
let output =
String.uppercase_ascii method ^
"&" ^
Uri.pct_encode component::`Userinfo uri ^
"&" ^ Uri.pct_encode component::`Userinfo collectedParamsString;
let signingKey =
Uri.pct_encode component::`Userinfo clientId ^
"&" ^ Uri.pct_encode component::`Userinfo clientSecret;
Cstruct.to_string (
Nocrypto.Hash.SHA1.hmac key::(Cstruct.of_string signingKey) (Cstruct.of_string output)
)
};
let signature =
signRequest
"post"
"https://api.twitter.com/1.1/statuses/update.json"
"kAcSOqF21Fu85e7zjz7ZN2U4ZRhfV3WpwPAoE3Z7kBw"
"LswwdoUaIvS8ltyTt5jkRh4J50vUPVVHtR2YPi5kE"
[
("status", ["Hello Ladies + Gentlemen, a signed OAuth request!"]),
("include_entities", ["true"]),
("oauth_consumer_key", ["xvz1evFS4wEEPTGEFPHBog"]),
("oauth_nonce", ["kYjzVBB8Y0ZFabxSWbWovY3uYSQ2pTgmZeNu2VS4cg"]),
("oauth_signature_method", ["HMAC-SHA1"]),
("oauth_timestamp", ["1318622958"]),
("oauth_token", ["370773112-GmHxMAgYyLbNEtIKZeRNFsMKPR9EyMZeS9weJAEb"]),
("oauth_version", ["1.0"])
];
/* let signature : string = "hCtSmYh+iHYCEqBWrE7C7hYmtUk */

编辑：我最初说Hannes是OCaml的nocrypto库的作者 - 它实际上是David Kaloper。对此非常抱歉，感谢丹尼尔·宾兹利指出这一点！