add 1200 byte HKDF test vector and a generator/verifier for it (#4074)

* add 1200 byte HKDF test vector and a generator/verifier for it

* exit non-zero when failing

* ugh

1 files changed, 39 insertions, 0 deletions

diff --git a/docs/development/custom-vectors/hkdf/generate_hkdf.py b/docs/development/custom-vectors/hkdf/generate_hkdf.py
new file mode 100644
index 00000000..767aedd8
--- /dev/null
+++ b/docs/development/custom-vectors/hkdf/generate_hkdf.py
@@ -0,0 +1,39 @@
+# This file is dual licensed under the terms of the Apache License, Version
+# 2.0, and the BSD License. See the LICENSE file in the root of this repository
+# for complete details.
+
+from __future__ import absolute_import, division, print_function
+
+import binascii
+
+from cryptography.hazmat.backends import default_backend
+from cryptography.hazmat.primitives import hashes
+from cryptography.hazmat.primitives.kdf.hkdf import HKDF
+
+IKM = binascii.unhexlify(b"0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b")
+L = 1200
+OKM = HKDF(
+    algorithm=hashes.SHA256(), length=L, salt=None, info=None,
+    backend=default_backend()
+).derive(IKM)
+
+
+def _build_vectors():
+    output = []
+    output.append("COUNT = 0")
+    output.append("Hash = SHA-256")
+    output.append("IKM = " + binascii.hexlify(IKM).decode("ascii"))
+    output.append("salt = ")
+    output.append("info = ")
+    output.append("L = {}".format(L))
+    output.append("OKM = " + binascii.hexlify(OKM).decode("ascii"))
+    return "\n".join(output)
+
+
+def _write_file(data, filename):
+    with open(filename, 'w') as f:
+        f.write(data)
+
+
+if __name__ == '__main__':
+    _write_file(_build_vectors(), 'hkdf.txt')