1 files changed, 23 insertions, 0 deletions
diff --git a/libblake_blake2xs_digest.c b/libblake_blake2xs_digest.c
new file mode 100644
index 0000000..0d4ffea
--- /dev/null
+++ b/libblake_blake2xs_digest.c
@@ -0,0 +1,23 @@
+/* See LICENSE file for copyright and license details. */
+#include "common.h"
+
+void
+libblake_blake2xs_digest(const struct libblake_blake2xs_state *state,
+                         uint_least32_t i /* start 0, increase by 1 until i * 32 >= desired hash length */,
+                         uint_least8_t len /* desired hash MIN(length - i * 32, 32) */,
+                         unsigned char output[static len]  /* output for hash offset by i * 32 */)
+{
+	struct libblake_blake2xs_state xstate;
+	struct libblake_blake2xs_params xparams;
+
+	xparams = state->xof_params;
+	xparams.node_offset = i;
+	xparams.digest_len = len;
+
+	libblake_internal_blake2xs_init0(&xstate, &xparams);
+
+	xstate.b2s.f[0] = UINT_LEAST32_C(0xFFFFffff);
+	xstate.b2s.t[0] = (uint_least32_t)state->xof_params.digest_len & UINT_LEAST32_C(0xFFFFffff);
+	libblake_internal_blake2s_compress(&xstate.b2s, state->intermediate);
+	libblake_internal_blake2s_output_digest(&xstate.b2s, (size_t)len, output);
+}