use digestif 1.2.0 API (mirage#215)

* use digestif 1.2.0 API Co-authored-by: Reynir Björnsson <[email protected]>
hannesm · Mar 19, 2024 · 4b757b1 · 4b757b1
1 parent fff44e5
commit 4b757b1
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Showing 5 changed files with 43 additions and 89 deletions.
diff --git a/ec/mirage_crypto_ec.ml b/ec/mirage_crypto_ec.ml
@@ -967,15 +967,22 @@ module Ed25519 = struct
 
   type priv = string
 
+  let sha512 datas =
+    let open Digestif.SHA512 in
+    let buf = Bytes.create digest_size in
+    let ctx = List.fold_left (feed_string ?off:None ?len:None) empty datas in
+    get_into_bytes ctx buf;
+    buf
+
   (* RFC 8032 *)
   let public secret =
     (* section 5.1.5 *)
     (* step 1 *)
-    let h = Digestif.SHA512.(digest_string secret |> to_raw_string) in
+    let h = sha512 [ secret ] in
     (* step 2 *)
     let s, rest =
-      Bytes.unsafe_of_string (String.sub h 0 key_len),
-      String.sub h key_len (String.length h - key_len)
+      Bytes.sub h 0 key_len,
+      Bytes.unsafe_to_string (Bytes.sub h key_len (Bytes.length h - key_len))
     in
     Bytes.set_uint8 s 0 ((Bytes.get_uint8 s 0) land 248);
     Bytes.set_uint8 s 31 (((Bytes.get_uint8 s 31) land 127) lor 64);
@@ -1009,13 +1016,11 @@ module Ed25519 = struct
   let sign ~key msg =
     (* section 5.1.6 *)
     let pub, (s, prefix) = public key in
-    let r = Digestif.SHA512.(digest_string (String.concat "" [ prefix; msg ]) |> to_raw_string) in
-    let r = Bytes.unsafe_of_string r in
+    let r = sha512 [ prefix; msg ] in
     reduce_l r;
     let r = Bytes.unsafe_to_string r in
     let r_big = scalar_mult_base_to_bytes r in
-    let k = Digestif.SHA512.(digest_string (String.concat "" [ r_big; pub; msg]) |> to_raw_string) in
-    let k = Bytes.unsafe_of_string k in
+    let k = sha512 [ r_big; pub; msg] in
     reduce_l k;
     let k = Bytes.unsafe_to_string k in
     let s_out = muladd k s r in
@@ -1041,10 +1046,7 @@ module Ed25519 = struct
         String.equal s'' s'
       in
       if s_smaller_l then begin
-        let k =
-          Digestif.SHA512.(digest_string (String.concat "" [ r ; key ; msg ]) |> to_raw_string)
-        in
-        let k = Bytes.unsafe_of_string k in
+        let k = sha512 [ r ; key ; msg ] in
         reduce_l k;
         let k = Bytes.unsafe_to_string k in
         let success, r' = double_scalar_mult k key s in

diff --git a/mirage-crypto-ec.opam b/mirage-crypto-ec.opam
@@ -30,7 +30,7 @@ depends: [
   "dune-configurator"
   "eqaf" {>= "0.7"}
   "mirage-crypto-rng" {=version}
-  "digestif" {>= "1.1.4"}
+  "digestif" {>= "1.2.0"}
   "hex" {with-test}
   "alcotest" {with-test & >= "0.8.1"}
   "ppx_deriving_yojson" {with-test}

diff --git a/mirage-crypto-pk.opam b/mirage-crypto-pk.opam
@@ -20,7 +20,7 @@ depends: [
   "randomconv" {with-test & >= "0.2.0"}
   "mirage-crypto" {=version}
   "mirage-crypto-rng" {=version}
-  "digestif" {>= "1.1.4"}
+  "digestif" {>= "1.2.0"}
   "zarith" {>= "1.13"}
   "eqaf" {>= "0.8"}
 ]

diff --git a/pk/mirage_crypto_pk.mli b/pk/mirage_crypto_pk.mli
@@ -187,15 +187,12 @@ module Rsa : sig
         was produced with the given [key] as per {{!sig_encode}sig_encode}, or
         [None] *)
 
-    type hash = [ `MD5 | `SHA1 | `SHA224 | `SHA256 | `SHA384 | `SHA512 ]
-    (** The type of supported hash algorithms. *)
-
-    val min_key : hash -> bits
+    val min_key : [< Digestif.hash' > `MD5 `SHA1 `SHA224 `SHA256 `SHA384 `SHA512 ] -> bits
     (** [min_key hash] is the minimum key size required by {{!sign}[sign]}. *)
 
     val sign : ?crt_hardening:bool -> ?mask:mask ->
-      hash:hash -> key:priv -> string or_digest ->
-      string
+      hash:[< Digestif.hash' > `MD5 `SHA1 `SHA224 `SHA256 `SHA384 `SHA512 ] ->
+      key:priv -> string or_digest -> string
     (** [sign ~crt_hardening ~mask ~hash ~key message] is the PKCS 1.5
         signature of [message], signed by the [key], using the hash function
         [hash]. This is the full signature, with the ASN-encoded message digest
@@ -208,8 +205,8 @@ module Rsa : sig
 
         @raise Invalid_argument if message is a [`Digest] of the wrong size.  *)
 
-    val verify : hashp:(hash -> bool) -> key:pub ->
-      signature:string -> string or_digest -> bool
+    val verify : hashp:([< Digestif.hash' > `MD5 `SHA1 `SHA224 `SHA256 `SHA384 `SHA512 ] -> bool) ->
+      key:pub -> signature:string -> string or_digest -> bool
     (** [verify ~hashp ~key ~signature message] checks that [signature] is the
         PKCS 1.5 signature of the [message] under the given [key].
 

diff --git a/pk/rsa.ml b/pk/rsa.ml
@@ -23,11 +23,6 @@ module Digest_or (H : Digestif.S) = struct
           invalid_arg "(`Digest _): %d bytes, expecting %d" n m
 end
 
-let digest_or (type a) ~(hash : a Digestif.hash) =
-  let module H = (val Digestif.module_of hash) in
-  let module D = Digest_or (H) in
-  D.digest_or
-
 exception Insufficient_key
 
 type pub = { e : Z.t ; n : Z.t }
@@ -274,69 +269,23 @@ module PKCS1 = struct
     String.length msg >= String.length asn &&
     String.equal asn (String.sub msg 0 (String.length asn))
 
-  type hash = [ `MD5 | `SHA1 | `SHA224 | `SHA256 | `SHA384 | `SHA512 ]
-
-  let digestif_or = function
-    | `MD5 -> digest_or ~hash:Digestif.md5
-    | `SHA1 -> digest_or ~hash:Digestif.sha1
-    | `SHA224 -> digest_or ~hash:Digestif.sha224
-    | `SHA256 -> digest_or ~hash:Digestif.sha256
-    | `SHA384 -> digest_or ~hash:Digestif.sha384
-    | `SHA512 -> digest_or ~hash:Digestif.sha512
-
-  let digestif_size = function
-    | `MD5 ->
-      let module H = (val Digestif.module_of Digestif.md5) in
-      H.digest_size
-    | `SHA1 ->
-      let module H = (val Digestif.module_of Digestif.sha1) in
-      H.digest_size
-    | `SHA224 ->
-      let module H = (val Digestif.module_of Digestif.sha224) in
-      H.digest_size
-    | `SHA256 ->
-      let module H = (val Digestif.module_of Digestif.sha256) in
-      H.digest_size
-    | `SHA384 ->
-      let module H = (val Digestif.module_of Digestif.sha384) in
-      H.digest_size
-    | `SHA512 ->
-      let module H = (val Digestif.module_of Digestif.sha512) in
-      H.digest_size
-
   let asn_of_hash, detect =
-    let md5 = "\x30\x20\x30\x0c\x06\x08\x2a\x86\x48\x86\xf7\x0d\x02\x05\x05\x00\x04\x10"
-    and sha1 = "\x30\x21\x30\x09\x06\x05\x2b\x0e\x03\x02\x1a\x05\x00\x04\x14"
-    and sha224 = "\x30\x2d\x30\x0d\x06\x09\x60\x86\x48\x01\x65\x03\x04\x02\x04\x05\x00\x04\x1c"
-    and sha256 = "\x30\x31\x30\x0d\x06\x09\x60\x86\x48\x01\x65\x03\x04\x02\x01\x05\x00\x04\x20"
-    and sha384 = "\x30\x41\x30\x0d\x06\x09\x60\x86\x48\x01\x65\x03\x04\x02\x02\x05\x00\x04\x30"
-    and sha512 = "\x30\x51\x30\x0d\x06\x09\x60\x86\x48\x01\x65\x03\x04\x02\x03\x05\x00\x04\x40"
+    let map = [
+      `MD5, "\x30\x20\x30\x0c\x06\x08\x2a\x86\x48\x86\xf7\x0d\x02\x05\x05\x00\x04\x10" ;
+      `SHA1, "\x30\x21\x30\x09\x06\x05\x2b\x0e\x03\x02\x1a\x05\x00\x04\x14" ;
+      `SHA224, "\x30\x2d\x30\x0d\x06\x09\x60\x86\x48\x01\x65\x03\x04\x02\x04\x05\x00\x04\x1c" ;
+      `SHA256, "\x30\x31\x30\x0d\x06\x09\x60\x86\x48\x01\x65\x03\x04\x02\x01\x05\x00\x04\x20" ;
+      `SHA384, "\x30\x41\x30\x0d\x06\x09\x60\x86\x48\x01\x65\x03\x04\x02\x02\x05\x00\x04\x30" ;
+      `SHA512, "\x30\x51\x30\x0d\x06\x09\x60\x86\x48\x01\x65\x03\x04\x02\x03\x05\x00\x04\x40"
+    ]
     in
-    (function
-      | `MD5 -> md5
-      | `SHA1 -> sha1
-      | `SHA224 -> sha224
-      | `SHA256 -> sha256
-      | `SHA384 -> sha384
-      | `SHA512 -> sha512),
-     (fun buf ->
-       if is_prefix md5 buf then
-         Some (`MD5, md5)
-       else if is_prefix sha1 buf then
-         Some (`SHA1, sha1)
-       else if is_prefix sha224 buf then
-         Some (`SHA224, sha224)
-       else if is_prefix sha256 buf then
-         Some (`SHA256, sha256)
-       else if is_prefix sha384 buf then
-         Some (`SHA384, sha384)
-       else if is_prefix sha512 buf then
-         Some (`SHA512, sha512)
-       else
-         None)
+    (fun h -> List.assoc h map),
+    (fun buf -> List.find_opt (fun (_, d) -> is_prefix d buf) map)
 
   let sign ?(crt_hardening = true) ?mask ~hash ~key msg =
-    let msg' = asn_of_hash hash ^ digestif_or hash msg in
+    let module H = (val Digestif.module_of_hash' (hash :> Digestif.hash')) in
+    let module D = Digest_or(H) in
+    let msg' = asn_of_hash hash ^ D.digest_or msg in
     sig_encode ~crt_hardening ?mask ~key msg'
 
   let verify ~hashp ~key ~signature msg =
@@ -346,11 +295,14 @@ module PKCS1 = struct
     Option.value
       (sig_decode ~key signature >>= fun buf ->
        detect buf >>| fun (hash, asn) ->
-       hashp hash && Eqaf.equal (asn ^ digestif_or hash msg) buf)
+       let module H = (val Digestif.module_of_hash' (hash :> Digestif.hash')) in
+       let module D = Digest_or(H) in
+       hashp hash && Eqaf.equal (asn ^ D.digest_or msg) buf)
       ~default:false
 
   let min_key hash =
-    (String.length (asn_of_hash hash) + digestif_size hash + min_pad + 2) * 8 + 1
+    let module H = (val Digestif.module_of_hash' (hash :> Digestif.hash')) in
+    (String.length (asn_of_hash hash) + H.digest_size + min_pad + 2) * 8 + 1
 end
 
 module MGF1 (H : Digestif.S) = struct
@@ -364,8 +316,11 @@ module MGF1 (H : Digestif.S) = struct
   let mgf ~seed len =
     let rec go acc c = function
       | 0 -> Bytes.sub (Bytes.concat Bytes.empty (List.rev acc)) 0 len
-      | n -> let h = Bytes.unsafe_of_string H.(digesti_string (iter2 seed (repr c)) |> to_raw_string) in
-             go (h :: acc) Int32.(succ c) (pred n) in
+      | n ->
+        let h = Bytes.create H.digest_size in
+        H.get_into_bytes (H.feedi_string H.empty (iter2 seed (repr c))) h;
+        go (h :: acc) Int32.(succ c) (pred n)
+    in
     go [] 0l (len // H.digest_size)
 
   let mask ~seed buf =