From b6a111602b2a7c870681a2672c7dac64e37f13c7 Mon Sep 17 00:00:00 2001
From: John Turner <jturner.usa@gmail.com>
Date: Fri, 5 Sep 2025 15:04:10 -0400
Subject: init

---
 .dir-locals.el    | 10 +++++++
 .flake8           |  2 ++
 .mypy.ini         |  2 ++
 bozo4/__init__.py | 88 +++++++++++++++++++++++++++++++++++++++++++++++++++++++
 bozo4/py.typed    |  0
 5 files changed, 102 insertions(+)
 create mode 100644 .dir-locals.el
 create mode 100644 .flake8
 create mode 100644 .mypy.ini
 create mode 100644 bozo4/__init__.py
 create mode 100644 bozo4/py.typed

diff --git a/.dir-locals.el b/.dir-locals.el
new file mode 100644
index 0000000..042b2ea
--- /dev/null
+++ b/.dir-locals.el
@@ -0,0 +1,10 @@
+((python-ts-mode . ((eval . (flycheck-mode 1))
+                    (eval . (flycheck-select-checker 'python-mypy))
+                    (eval . (flycheck-add-next-checker 'python-mypy (cons t 'python-flake8)))
+                    (eval . (add-hook 'before-save-hook 'fmt-current-buffer nil t))
+                    (eval . (setq-local fmt-executable "black"
+                                        fmt-args '("-")))))
+ (meson-mode
+  . ((fmt-executable . "meson")
+     (fmt-args . ("format" "-"))
+     (eval . (add-hook 'before-save-hook 'fmt-current-buffer nil t)))))
diff --git a/.flake8 b/.flake8
new file mode 100644
index 0000000..79a16af
--- /dev/null
+++ b/.flake8
@@ -0,0 +1,2 @@
+[flake8]
+max-line-length = 120
\ No newline at end of file
diff --git a/.mypy.ini b/.mypy.ini
new file mode 100644
index 0000000..1d781df
--- /dev/null
+++ b/.mypy.ini
@@ -0,0 +1,2 @@
+[mypy]
+strict = true
\ No newline at end of file
diff --git a/bozo4/__init__.py b/bozo4/__init__.py
new file mode 100644
index 0000000..0f2e2fa
--- /dev/null
+++ b/bozo4/__init__.py
@@ -0,0 +1,88 @@
+import hmac
+from urllib.parse import quote as quote_url
+from hashlib import sha256
+from datetime import datetime
+from typing import Dict
+
+
+def _s3v4_sign(msg: str, key: bytes) -> bytes:
+    return hmac.new(key, msg.encode(), sha256).digest()
+
+
+def s3v4_datetime_string(dt: datetime) -> str:
+    return dt.strftime("%Y%m%dT%H%M%SZ")
+
+
+def s3v4_sign_request(
+    endpoint: str,
+    region: str,
+    access_key: str,
+    secret_key: str,
+    request_method: str,
+    date: datetime,
+    payload_hash: str,
+    uri: str,
+    parameters: Dict[str, str],
+    headers: Dict[str, str],
+    service: str,
+) -> str:
+    algo = "AWS4-HMAC-SHA256"
+    datestamp = date.strftime("%Y%m%d")
+    amzdate = s3v4_datetime_string(date)
+
+    canon_uri = quote_url(uri)
+
+    signed_headers = ";".join(
+        key for key in sorted(key.lower() for key in headers.keys())
+    )
+
+    quoted_parameters = {
+        quote_url(key): quote_url(value) for key, value in parameters.items()
+    }
+
+    canon_parameters = "&".join(
+        f"{key}={val}"
+        for key, val in sorted(quoted_parameters.items(), key=lambda p: p[0])
+    )
+
+    def fixup_header_value(val: str) -> str:
+        return " ".join(w for w in val.strip().split())
+
+    canon_headers = "".join(
+        f"{key.lower()}:{fixup_header_value(val)}\n"
+        for key, val in sorted(headers.items(), key=lambda h: h[0])
+    )
+
+    canon_request = "\n".join(
+        x
+        for x in [
+            request_method,
+            canon_uri,
+            canon_parameters,
+            canon_headers,
+            signed_headers,
+            payload_hash,
+        ]
+    )
+
+    hashed_request = sha256(canon_request.encode()).hexdigest().lower()
+
+    credential_scope = f"{datestamp}/{region}/{service}/aws4_request"
+
+    s = f"{algo}\n{amzdate}\n{credential_scope}\n{hashed_request}"
+
+    k = f"AWS4{secret_key}".encode()
+    k = _s3v4_sign(msg=datestamp, key=k)
+    k = _s3v4_sign(msg=region, key=k)
+    k = _s3v4_sign(msg=service, key=k)
+    k = _s3v4_sign(msg="aws4_request", key=k)
+    sig = _s3v4_sign(msg=s, key=k).hex().lower()
+
+    return ", ".join(
+        x
+        for x in [
+            f"{algo} Credential={access_key}/{credential_scope}",
+            f"SignedHeaders={signed_headers}",
+            f"Signature={sig}",
+        ]
+    )
diff --git a/bozo4/py.typed b/bozo4/py.typed
new file mode 100644
index 0000000..e69de29
-- 
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