core:crypto/hash: Add a generic higher level hash interface

There is a lot of code duplicated in convenience methods in each hash
implementation, and having a generic hash type makes implementing
higher-level constructs such as HMAC significantly easier down the road.

core/crypto/blake2b/blake2b.odin

@@ -7,121 +7,33 @@ package blake2b
     List of contributors:
         zhibog, dotbmp:  Initial implementation.
 
-    Interface for the BLAKE2b hashing algorithm.
-    BLAKE2b and BLAKE2s share the implementation in the _blake2 package.
+    Interface for the vanilla BLAKE2b hashing algorithm.
 */
 
-import "core:io"
-import "core:os"
-
 import "../_blake2"
 
-/*
-    High level API
-*/
-
 DIGEST_SIZE :: 64
 
-// hash_string will hash the given input and return the
-// computed hash
-hash_string :: proc(data: string) -> [DIGEST_SIZE]byte {
-	return hash_bytes(transmute([]byte)(data))
-}
-
-// hash_bytes will hash the given input and return the
-// computed hash
-hash_bytes :: proc(data: []byte) -> [DIGEST_SIZE]byte {
-	hash: [DIGEST_SIZE]byte
-	ctx: Context
-	cfg: _blake2.Blake2_Config
-	cfg.size = _blake2.BLAKE2B_SIZE
-	ctx.cfg = cfg
-	init(&ctx)
-	update(&ctx, data)
-	final(&ctx, hash[:])
-	return hash
-}
-
-// hash_string_to_buffer will hash the given input and assign the
-// computed hash to the second parameter.
-// It requires that the destination buffer is at least as big as the digest size
-hash_string_to_buffer :: proc(data: string, hash: []byte) {
-	hash_bytes_to_buffer(transmute([]byte)(data), hash)
-}
-
-// hash_bytes_to_buffer will hash the given input and write the
-// computed hash into the second parameter.
-// It requires that the destination buffer is at least as big as the digest size
-hash_bytes_to_buffer :: proc(data, hash: []byte) {
-	ctx: Context
-	cfg: _blake2.Blake2_Config
-	cfg.size = _blake2.BLAKE2B_SIZE
-	ctx.cfg = cfg
-	init(&ctx)
-	update(&ctx, data)
-	final(&ctx, hash)
-}
-
-// hash_stream will read the stream in chunks and compute a
-// hash from its contents
-hash_stream :: proc(s: io.Stream) -> ([DIGEST_SIZE]byte, bool) {
-	hash: [DIGEST_SIZE]byte
-	ctx: Context
-	cfg: _blake2.Blake2_Config
-	cfg.size = _blake2.BLAKE2B_SIZE
-	ctx.cfg = cfg
-	init(&ctx)
-
-	buf := make([]byte, 512)
-	defer delete(buf)
-
-	read := 1
-	for read > 0 {
-		read, _ = io.read(s, buf)
-		if read > 0 {
-			update(&ctx, buf[:read])
-		}
-	}
-	final(&ctx, hash[:])
-	return hash, true
-}
-
-// hash_file will read the file provided by the given handle
-// and compute a hash
-hash_file :: proc(hd: os.Handle, load_at_once := false) -> ([DIGEST_SIZE]byte, bool) {
-	if !load_at_once {
-		return hash_stream(os.stream_from_handle(hd))
-	} else {
-		if buf, ok := os.read_entire_file(hd); ok {
-			return hash_bytes(buf[:]), ok
-		}
-	}
-	return [DIGEST_SIZE]byte{}, false
-}
-
-hash :: proc {
-	hash_stream,
-	hash_file,
-	hash_bytes,
-	hash_string,
-	hash_bytes_to_buffer,
-	hash_string_to_buffer,
-}
-
-/*
-    Low level API
-*/
-
 Context :: _blake2.Blake2b_Context
 
 init :: proc(ctx: ^Context) {
-	_blake2.init(ctx)
+	cfg: _blake2.Blake2_Config
+	cfg.size = _blake2.BLAKE2B_SIZE
+	_blake2.init(ctx, &cfg)
 }
 
 update :: proc(ctx: ^Context, data: []byte) {
 	_blake2.update(ctx, data)
 }
 
-final :: proc(ctx: ^Context, hash: []byte) {
-	_blake2.final(ctx, hash)
+final :: proc(ctx: ^Context, hash: []byte, finalize_clone: bool = false) {
+	_blake2.final(ctx, hash, finalize_clone)
+}
+
+clone :: proc(ctx, other: ^Context) {
+	_blake2.clone(ctx, other)
+}
+
+reset :: proc(ctx: ^Context) {
+	_blake2.reset(ctx)
 }