add vdk_aeser lib (untested)

libs/vdk_aeser/src/vdk_aeser.ts

@@ -0,0 +1,97 @@
+/**
+ * Miscellaneous serialization/deserialization functions
+ *
+ * Refs:
+ * 1. https://github.com/aeternity/protocol/blob/master/node/api/api_encoding.md
+ * 2. https://github.com/aeternity/protocol/blob/master/serializations.md
+ *
+ * @module
+ */
+
+
+import * as vdk_base58 from './jex_include/local-vdk_base58-0.1.0/dist/vdk_base58.js';
+import * as vdk_binary from './jex_include/local-vdk_binary-0.1.0/dist/vdk_binary.js';
+
+
+export {
+    pubkey2ak_str,
+    add_check_bytes,
+    shasha4
+}
+
+
+
+/**
+ * Take a public key as 32 bytes and encode it in AE API ak_... notation
+ *
+ * Refs:
+ * 1. https://github.com/aeternity/protocol/blob/master/node/api/api_encoding.md
+ */
+async function
+pubkey2ak_str
+    (pubkey_bytes : Uint8Array)
+    : Promise<string>
+{
+    let checked_pubkey_bytes : Uint8Array = await add_check_bytes(pubkey_bytes);
+    let b58_str              : string     = vdk_base58.encode(checked_pubkey_bytes);
+    return ("ak_" + b58_str);
+}
+
+
+
+/**
+ * Take the double-sha of a byte array and return the first 4 bytes
+ *
+ * TypeScript equivalent of
+ *
+ * ```erlang
+ * add_check_bytes(Bin) when is_binary(Bin) ->
+ *     <<Check:4/binary, _/binary>> = sha256(sha256(Bin)),
+ *     <<Bin/binary, Check/binary>>.
+ * ```
+ *
+ * Refs:
+ * 1. https://developer.mozilla.org/en-US/docs/Web/API/SubtleCrypto/digest
+ * 2. https://github.com/aeternity/protocol/blob/master/node/api/api_encoding.md
+ * 3. https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/ArrayBuffer/slice
+ *
+ * is async because everything is retarded.
+*/
+async function
+add_check_bytes
+    (pubkey_bytes : Uint8Array)
+    : Promise<Uint8Array>
+{
+    let check_bytes : Uint8Array = await shasha4(pubkey_bytes);
+    return vdk_binary.bytes_concat(pubkey_bytes, check_bytes);
+}
+
+
+/**
+ * Take the double-sha of a byte array and return the first 4 bytes
+ *
+ * TypeScript equivalent of
+ *
+ * ```erlang
+ * shasha4(Bin) when is_binary(Bin) ->
+ *     <<Check:4/binary, _/binary>> = sha256(sha256(Bin)),
+ *     <<Check/binary>>.
+ * ```
+ *
+ * Refs:
+ * 1. https://developer.mozilla.org/en-US/docs/Web/API/SubtleCrypto/digest
+ * 2. https://github.com/aeternity/protocol/blob/master/node/api/api_encoding.md
+ * 3. https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/ArrayBuffer/slice
+ *
+ * is async because everything is retarded.
+*/
+async function
+shasha4
+    (pubkey_bytes : Uint8Array)
+    : Promise<Uint8Array>
+{
+    let shad_bytes      : ArrayBuffer = await crypto.subtle.digest("SHA-256", pubkey_bytes);
+    let shashad_bytes   : ArrayBuffer = await crypto.subtle.digest("SHA-256", shad_bytes);
+    let shashad_bytes_4 : ArrayBuffer = shashad_bytes.slice(0, 4);
+    return new Uint8Array(shashad_bytes_4);
+}