btrfs-progs: tests: add SHA256

In order to drop dependency on SSL library to compute MD5 in fssum,
we'll use the reference implementation from RFC 6234.

The checksum is not in a cryptographically sensitive context, but we're
going to skip MD5 and SHA-1 anyway.

Signed-off-by: David Sterba <dsterba@suse.com>

1 files changed, 28 insertions, 0 deletions

diff --git a/tests/sha-private.h b/tests/sha-private.h
new file mode 100644
index 00000000..6e9c4520
--- /dev/null
+++ b/tests/sha-private.h
@@ -0,0 +1,28 @@
+/************************ sha-private.h ************************/
+/***************** See RFC 6234 for details. *******************/
+#ifndef _SHA_PRIVATE__H
+#define _SHA_PRIVATE__H
+/*
+ * These definitions are defined in FIPS 180-3, section 4.1.
+ * Ch() and Maj() are defined identically in sections 4.1.1,
+ * 4.1.2, and 4.1.3.
+ *
+ * The definitions used in FIPS 180-3 are as follows:
+ */
+
+#ifndef USE_MODIFIED_MACROS
+#define SHA_Ch(x,y,z)        (((x) & (y)) ^ ((~(x)) & (z)))
+#define SHA_Maj(x,y,z)       (((x) & (y)) ^ ((x) & (z)) ^ ((y) & (z)))
+#else /* USE_MODIFIED_MACROS */
+/*
+ * The following definitions are equivalent and potentially faster.
+ */
+
+#define SHA_Ch(x, y, z)      (((x) & ((y) ^ (z))) ^ (z))
+#define SHA_Maj(x, y, z)     (((x) & ((y) | (z))) | ((y) & (z)))
+
+#endif /* USE_MODIFIED_MACROS */
+
+#define SHA_Parity(x, y, z)  ((x) ^ (y) ^ (z))
+
+#endif /* _SHA_PRIVATE__H */