# SHA1

Calculate SHA-1 digests in Elm.

This package can take a message as a `String` or `List Int` ("bytes") calculate
SHA-1 digests, and represent them in [hexadecimal], [base64] or a `List Int` (as
"bytes").

[hexadecimal]: https://en.wikipedia.org/wiki/Hexadecimal
[base64]: https://en.wikipedia.org/wiki/Base64

# [Documentation](https://package.elm-lang.org/packages/TSFoster/elm-sha1/latest/SHA1)

## IMPORTANT UPGRADE NOTES

- **Upgrade to elm-sha1 >= v1.0.3 for use with elm v0.19.1.** An update to the
  elm compiler to fix a [regression][issue-1945] will break versions of this
  package before v1.0.3. Please ensure this package is updated to at least v1.0.3
  when upgrading to elm version 0.19.1.

- [There was an issue][issue-2] regarding input data of 311 bytes in versions
  1.0.0 and 1.0.1 of this library. If you are using either of these versions, it
  is highly recommended that you upgrade as soon as possible.

[issue-2]: https://github.com/TSFoster/elm-sha1/issues/2
[issue-1945]: https://github.com/elm/compiler/issues/1945

## Examples

```elm
import SHA1

digest1 : SHA1.Digest
digest1 = SHA1.fromString "string"

digest2 : SHA1.Digest
digest2 = SHA1.fromBytes [0x00, 0xFF, 0xCE, 0x35, 0x74]


SHA1.toHex digest1
--> "ecb252044b5ea0f679ee78ec1a12904739e2904d"

SHA1.toBase64 digest2
--> "gHweOF5Lyg+Ha7ujrlYwNa/Hwgk="

SHA1.toBytes digest1
--> [ 0xEC, 0xB2, 0x52, 0x04, 0x4B
--> , 0x5E, 0xA0, 0xF6, 0x79, 0xEE
--> , 0x78, 0xEC, 0x1A, 0x12, 0x90
--> , 0x47, 0x39, 0xE2, 0x90, 0x4D
--> ]
```

## Validation

Not officially validated through [CAVP](http://csrc.nist.gov/groups/STM/cavp/)/[CMVP](https://csrc.nist.gov/groups/STM/cmvp/).

Tested against hashes in [tests/Tests.elm](https://github.com/TSFoster/elm-sha1/blob/master/tests/Tests.elm), indirectly in [romariolopezc/elm-hmac-sha1’s tests](https://github.com/romariolopezc/elm-hmac-sha1/blob/master/tests/HmacSha1Test.elm), and personal use of and the [tests](https://github.com/TSFoster/elm-uuid/blob/2.2.0/tests/Tests.elm) for [TSFoster/elm-uuid](https://package.elm-lang.org/packages/TSFoster/elm-uuid/latest/).

Please note that SHA-1 is not “[considered secure against well-funded opponents](https://en.wikipedia.org/wiki/SHA-1)”, but it does have its uses, including, but not limited to, [version 5 UUIDs](https://package.elm-lang.org/packages/TSFoster/elm-uuid/latest/UUID#childNamed).