core/crypto: Exile keccak, md5 and sha1 to legacy

In an perfect world these would just be removed, but the world is
imperfect, and people are forced to interact/interface with things
that are broken.

core/crypto/README.md

@@ -10,13 +10,13 @@ Please see the chart below for the options.
 |:-------------------------------------------------------------------------------------------------------------|:-----------------|
 | [BLAKE2B](https://datatracker.ietf.org/doc/html/rfc7693)                                                     | ✔️ |
 | [BLAKE2S](https://datatracker.ietf.org/doc/html/rfc7693)                                                     | ✔️ |
-| [Keccak](https://nvlpubs.nist.gov/nistpubs/FIPS/NIST.FIPS.202.pdf)                                           | ✔️ |
-| [MD5](https://datatracker.ietf.org/doc/html/rfc1321)                                                         | ✔️ |
-| [SHA-1](https://datatracker.ietf.org/doc/html/rfc3174)                                                       | ✔️ |
 | [SHA-2](https://csrc.nist.gov/csrc/media/publications/fips/180/2/archive/2002-08-01/documents/fips180-2.pdf) | ✔️ |
 | [SHA-3](https://nvlpubs.nist.gov/nistpubs/FIPS/NIST.FIPS.202.pdf)                                            | ✔️ |
 | [SHAKE](https://nvlpubs.nist.gov/nistpubs/FIPS/NIST.FIPS.202.pdf)                                            | ✔️ |
 | [SM3](https://datatracker.ietf.org/doc/html/draft-sca-cfrg-sm3-02)                                           | ✔️ |
+| legacy/[Keccak](https://nvlpubs.nist.gov/nistpubs/FIPS/NIST.FIPS.202.pdf)                                    | ✔️ |
+| legacy/[MD5](https://datatracker.ietf.org/doc/html/rfc1321)                                                  | ✔️ |
+| legacy/[SHA-1](https://datatracker.ietf.org/doc/html/rfc3174)                                                | ✔️ |
 
 #### High level API
 Each hash algorithm contains a procedure group named `hash`, or if the algorithm provides more than one digest size `hash_<size>`\*.  

core/crypto/legacy/README.md

@@ -0,0 +1,10 @@
+# crypto/legacy
+
+These are algorithms that are shipped solely for the purpose of
+interoperability with legacy systems.  The use of these packages in
+any other capacity is discouraged, especially those that are known
+to be broken.
+
+- keccak - The draft version of the algorithm that became SHA-3
+- MD5 - Broken (https://eprint.iacr.org/2005/075)
+- SHA-1 - Broken (https://eprint.iacr.org/2017/190)

core/crypto/legacy/keccak/keccak.odin

@@ -14,7 +14,7 @@ package keccak
 import "core:io"
 import "core:os"
 
-import "../_sha3"
+import "../../_sha3"
 
 /*
     High level API