OCaml中的HMAC-SHA1簽名？

Question

我試圖向Twitter API發出請求，並且他們要求我簽署我的請求。最後一部分需要通過HMAC-SHA1哈希算法進行簽名。有沒有簡單的方法來獲得它？

Answer 1

漢納斯伸出手來給我答案（在ReasonML語法下面，而不是OCaml的）：

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

有了這樣的，這裏是從Twitter API doc（PARAMS翻譯和值也採取了簽字功能從該頁面，以便輸出可驗證是正確的）：

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 */ 

編輯：我原來說的Hannes是OCaml中的nocrypto庫的作者 - 它實際上是大衛Kaloper。非常抱歉，並感謝DanielBünzli指出了這一點！