1 files changed, 61 insertions, 0 deletions
diff --git a/crypto/sha512-select.c b/crypto/sha512-select.c
new file mode 100644
index 00000000..ecd567bd
--- /dev/null
+++ b/crypto/sha512-select.c
@@ -0,0 +1,61 @@
+/*
+ * Top-level vtables to select a SHA-512 implementation.
+ */
+
+#include <assert.h>
+#include <stdlib.h>
+
+#include "putty.h"
+#include "ssh.h"
+#include "sha512.h"
+
+static const ssh_hashalg *const real_sha512_algs[] = {
+#if HAVE_NEON_SHA512
+    &ssh_sha512_neon,
+#endif
+    &ssh_sha512_sw,
+    NULL,
+};
+
+static const ssh_hashalg *const real_sha384_algs[] = {
+#if HAVE_NEON_SHA512
+    &ssh_sha384_neon,
+#endif
+    &ssh_sha384_sw,
+    NULL,
+};
+
+static ssh_hash *sha512_select(const ssh_hashalg *alg)
+{
+    const ssh_hashalg *const *real_algs =
+        (const ssh_hashalg *const *)alg->extra;
+
+    for (size_t i = 0; real_algs[i]; i++) {
+        const ssh_hashalg *alg = real_algs[i];
+        const struct sha512_extra *alg_extra =
+            (const struct sha512_extra *)alg->extra;
+        if (check_availability(alg_extra))
+            return ssh_hash_new(alg);
+    }
+
+    /* We should never reach the NULL at the end of the list, because
+     * the last non-NULL entry should be software-only SHA-512, which
+     * is always available. */
+    unreachable("sha512_select ran off the end of its list");
+}
+
+const ssh_hashalg ssh_sha512 = {
+    .new = sha512_select,
+    .hlen = 64,
+    .blocklen = 128,
+    HASHALG_NAMES_ANNOTATED("SHA-512", "dummy selector vtable"),
+    .extra = real_sha512_algs,
+};
+
+const ssh_hashalg ssh_sha384 = {
+    .new = sha512_select,
+    .hlen = 48,
+    .blocklen = 128,
+    HASHALG_NAMES_ANNOTATED("SHA-384", "dummy selector vtable"),
+    .extra = real_sha384_algs,
+};