Provide and use crypto_ro{l,r}_u{32,64}().

Various code in libcrypto needs bitwise rotation - rather than defining
different versions across the code base, provide a common set that can
be reused. Any sensible compiler optimises these to a single instruction
where the architecture supports it, which means we can ditch the inline
assembly.

On the chance that we need to provide a platform specific versions, this
follows the approach used in BN where a MD crypto_arch.h header could be
added in the future, which would then provide more specific versions of
these functions.

ok tb@

1 files changed, 33 insertions, 1 deletions

diff --git a/src/lib/libcrypto/crypto_internal.h b/src/lib/libcrypto/crypto_internal.h
index af2a87216e..fa1dc504f7 100644
--- a/src/lib/libcrypto/crypto_internal.h
+++ b/src/lib/libcrypto/crypto_internal.h
@@ -1,4 +1,4 @@
-/*      $OpenBSD: crypto_internal.h,v 1.1 2023/04/12 04:40:39 jsing Exp $ */
+/*      $OpenBSD: crypto_internal.h,v 1.2 2023/04/12 04:54:15 jsing Exp $ */
 /*
  * Copyright (c) 2023 Joel Sing <jsing@openbsd.org>
  *
@@ -31,4 +31,36 @@ crypto_store_htobe64(uint8_t *dst, uint64_t v)
 }
 #endif
 
+#ifndef HAVE_CRYPTO_ROL_U32
+static inline uint32_t
+crypto_rol_u32(uint32_t v, size_t shift)
+{
+        return (v << shift) | (v >> (32 - shift));
+}
+#endif
+
+#ifndef HAVE_CRYPTO_ROR_U32
+static inline uint32_t
+crypto_ror_u32(uint32_t v, size_t shift)
+{
+        return (v << (32 - shift)) | (v >> shift);
+}
+#endif
+
+#ifndef HAVE_CRYPTO_ROL_U64
+static inline uint64_t
+crypto_rol_u64(uint64_t v, size_t shift)
+{
+        return (v << shift) | (v >> (64 - shift));
+}
+#endif
+
+#ifndef HAVE_CRYPTO_ROR_U64
+static inline uint64_t
+crypto_ror_u64(uint64_t v, size_t shift)
+{
+        return (v << (64 - shift)) | (v >> shift);
+}
+#endif
+
 #endif