restore a subset of the rand module (#708)

* restore a subset of the rand module

* flake

* remove cleanup, go ahead and assume status will always be 1

* lighten and add power

1 files changed, 40 insertions, 0 deletions

diff --git a/src/OpenSSL/rand.py b/src/OpenSSL/rand.py
new file mode 100644
index 0000000..d2c1767
--- /dev/null
+++ b/src/OpenSSL/rand.py
@@ -0,0 +1,40 @@
+"""
+PRNG management routines, thin wrappers.
+"""
+
+from OpenSSL._util import lib as _lib
+
+
+def add(buffer, entropy):
+    """
+    Mix bytes from *string* into the PRNG state.
+
+    The *entropy* argument is (the lower bound of) an estimate of how much
+    randomness is contained in *string*, measured in bytes.
+
+    For more information, see e.g. :rfc:`1750`.
+
+    This function is only relevant if you are forking Python processes and
+    need to reseed the CSPRNG after fork.
+
+    :param buffer: Buffer with random data.
+    :param entropy: The entropy (in bytes) measurement of the buffer.
+
+    :return: :obj:`None`
+    """
+    if not isinstance(buffer, bytes):
+        raise TypeError("buffer must be a byte string")
+
+    if not isinstance(entropy, int):
+        raise TypeError("entropy must be an integer")
+
+    _lib.RAND_add(buffer, len(buffer), entropy)
+
+
+def status():
+    """
+    Check whether the PRNG has been seeded with enough data.
+
+    :return: 1 if the PRNG is seeded enough, 0 otherwise.
+    """
+    return _lib.RAND_status()