SHA1

SHA-1 is a cryptographic hash function. Although it is no longer considered cryptographically secure (as collisions can be found faster than brute force), it is still very suitable for a broad range of uses, and is a lot stronger than MD5.

This package provides a way of creating SHA-1 digests from Bytes, Strings, List Ints (where each Int is between 0 and 255, and represents a byte). It can also take those Digests and format them in hexadecimal or base64 notation. Alternatively, you can get the binary digest, using either Bytes or List Int to represent the bytes.

type Digest

A type to represent a message digest. SHA1.Digests are equatable, and you may want to consider keeping any digests you need in your Model as Digests, not as Strings created by toHex or toBase64.

Creating digests

fromString : String -> Digest

Create a digest from a String.

"hello world" |> SHA1.fromString |> SHA1.toHex
--> "2aae6c35c94fcfb415dbe95f408b9ce91ee846ed"

Formatting digests

toHex : Digest -> String

One of the two canonical ways of representing a SHA-1 digest is with 40 hexadecimal digits.

"And our friends are all aboard"
    |> SHA1.fromString
    |> SHA1.toHex
--> "f9a0c23ddcd40f6956b0cf59cd9b8800d71de73d"

toBase64 : Digest -> String

One of the two canonical ways of representing a SHA-1 digest is in a 20 digit long Base64 binary to ASCII text encoding.

"Many more of them live next door"
    |> SHA1.fromString
    |> SHA1.toBase64
--> "jfL0oVb5xakab6BMLplGe2XPbj8="

Binary data

fromElmBytes : Bytes -> Digest

Create a digest from a Bytes

import Bytes.Encode as Encode
import Bytes exposing (Bytes, Endianness(..))


buffer : Bytes
buffer = Encode.encode (Encode.unsignedInt32 BE 42)


SHA1.fromElmBytes buffer
    |> SHA1.toHex
    --> "25f0c736f1fad0770bbb9a265ded159517c1e68c"

toElmBytes : Digest -> Bytes

Turn a digest into Bytes.

The digest is stored as 5 big-endian 32-bit unsigned integers, so the width is 20 bytes or 160 bits.

fromBytes : List Int -> Digest

Sometimes you have binary data that's not representable in a string. Create a digest from the raw "bytes", i.e. a List of Ints. Any items not between 0 and 255 are discarded.

SHA1.fromBytes [72, 105, 33, 32, 240, 159, 152, 132]
--> SHA1.fromString "Hi! 😄"


[0x00, 0xFF, 0x34, 0xA5] |> SHA1.fromBytes |> SHA1.toBase64
--> "sVQuFckyE6K3fsdLmLHmq8+J738="

toBytes : Digest -> List Int

Turn a digest into List Int

"And the band begins to play"
    |> SHA1.fromString
    |> SHA1.toBytes
--> [ 0xF3, 0x08, 0x73, 0x13
--> , 0xD6, 0xBC, 0xE5, 0x5B
--> , 0x60, 0x0C, 0x69, 0x2F
--> , 0xE0, 0x92, 0xF4, 0x53
--> , 0x87, 0x3F, 0xAE, 0x91
--> ]

Modules

SHA1

TSFoster/elm-sha1/1.1.0

SHA1

Creating digests

Formatting digests

Binary data

Modules