Add Botan crypto lib as a vendor library

vendor/botan/shake/shake.odin

@@ -0,0 +1,159 @@
+package shake
+
+/*
+    Copyright 2021 zhibog
+    Made available under the BSD-3 license.
+
+    List of contributors:
+        zhibog, dotbmp:  Initial implementation.
+
+    Interface for the SHAKE hashing algorithm.
+    The hash will be computed via bindings to the Botan crypto library
+*/
+
+import "core:os"
+import "core:io"
+
+import botan "../bindings"
+
+/*
+    High level API
+*/
+
+// hash_string_128 will hash the given input and return the
+// computed hash
+hash_string_128 :: proc(data: string) -> [16]byte {
+    return hash_bytes_128(transmute([]byte)(data))
+}
+
+// hash_bytes_128 will hash the given input and return the
+// computed hash
+hash_bytes_128 :: proc(data: []byte) -> [16]byte {
+    hash: [16]byte
+    ctx: botan.hash_t
+    botan.hash_init(&ctx, botan.HASH_SHAKE_128, 0)
+    botan.hash_update(ctx, len(data) == 0 ? nil : &data[0], uint(len(data)))
+    botan.hash_final(ctx, &hash[0])
+    botan.hash_destroy(ctx)
+    return hash
+}
+
+// hash_stream_128 will read the stream in chunks and compute a
+// hash from its contents
+hash_stream_128 :: proc(s: io.Stream) -> ([16]byte, bool) {
+    hash: [16]byte
+    ctx: botan.hash_t
+    botan.hash_init(&ctx, botan.HASH_SHAKE_128, 0)
+    buf := make([]byte, 512)
+    defer delete(buf)
+    i := 1
+    for i > 0 {
+        i, _ = s->impl_read(buf)
+        if i > 0 {
+            botan.hash_update(ctx, len(buf) == 0 ? nil : &buf[0], uint(i))
+        } 
+    }
+    botan.hash_final(ctx, &hash[0])
+    botan.hash_destroy(ctx)
+    return hash, true 
+}
+
+// hash_file_128 will read the file provided by the given handle
+// and compute a hash
+hash_file_128 :: proc(hd: os.Handle, load_at_once := false) -> ([16]byte, bool) {
+    if !load_at_once {
+        return hash_stream_128(os.stream_from_handle(hd))
+    } else {
+        if buf, ok := os.read_entire_file(hd); ok {
+            return hash_bytes_128(buf[:]), ok
+        }
+    }
+    return [16]byte{}, false
+}
+
+hash_128 :: proc {
+    hash_stream_128,
+    hash_file_128,
+    hash_bytes_128,
+    hash_string_128,
+}
+
+// hash_string_256 will hash the given input and return the
+// computed hash
+hash_string_256 :: proc(data: string) -> [32]byte {
+    return hash_bytes_256(transmute([]byte)(data))
+}
+
+// hash_bytes_256 will hash the given input and return the
+// computed hash
+hash_bytes_256 :: proc(data: []byte) -> [32]byte {
+    hash: [32]byte
+    ctx: botan.hash_t
+    botan.hash_init(&ctx, botan.HASH_SHAKE_256, 0)
+    botan.hash_update(ctx, len(data) == 0 ? nil : &data[0], uint(len(data)))
+    botan.hash_final(ctx, &hash[0])
+    botan.hash_destroy(ctx)
+    return hash
+}
+
+// hash_stream_256 will read the stream in chunks and compute a
+// hash from its contents
+hash_stream_256 :: proc(s: io.Stream) -> ([32]byte, bool) {
+    hash: [32]byte
+    ctx: botan.hash_t
+    botan.hash_init(&ctx, botan.HASH_SHAKE_256, 0)
+    buf := make([]byte, 512)
+    defer delete(buf)
+    i := 1
+    for i > 0 {
+        i, _ = s->impl_read(buf)
+        if i > 0 {
+            botan.hash_update(ctx, len(buf) == 0 ? nil : &buf[0], uint(i))
+        } 
+    }
+    botan.hash_final(ctx, &hash[0])
+    botan.hash_destroy(ctx)
+    return hash, true 
+}
+
+// hash_file_256 will read the file provided by the given handle
+// and compute a hash
+hash_file_256 :: proc(hd: os.Handle, load_at_once := false) -> ([32]byte, bool) {
+    if !load_at_once {
+        return hash_stream_256(os.stream_from_handle(hd))
+    } else {
+        if buf, ok := os.read_entire_file(hd); ok {
+            return hash_bytes_256(buf[:]), ok
+        }
+    }
+    return [32]byte{}, false
+}
+
+hash_256 :: proc {
+    hash_stream_256,
+    hash_file_256,
+    hash_bytes_256,
+    hash_string_256,
+}
+
+/*
+    Low level API
+*/
+
+Shake_Context :: botan.hash_t
+
+init :: proc "contextless" (ctx: ^botan.hash_t, hash_size := 256) {
+    switch hash_size {
+        case 128: botan.hash_init(ctx, botan.HASH_SHAKE_128, 0)
+        case 256: botan.hash_init(ctx, botan.HASH_SHAKE_256, 0)
+    }
+}
+
+update :: proc "contextless" (ctx: ^botan.hash_t, data: []byte) {
+    botan.hash_update(ctx^, len(data) == 0 ? nil : &data[0], uint(len(data)))
+}
+
+final :: proc "contextless" (ctx: ^botan.hash_t, hash: []byte) {
+    botan.hash_final(ctx^, &hash[0])
+    botan.hash_destroy(ctx^)
+}