1 files changed, 33 insertions, 0 deletions
diff --git a/libkeccak_state_initialise.c b/libkeccak_state_initialise.c
new file mode 100644
index 0000000..2559f47
--- /dev/null
+++ b/libkeccak_state_initialise.c
@@ -0,0 +1,33 @@
+/* See LICENSE file for copyright and license details. */
+#include "common.h"
+
+
+/**
+ * Initialise a state according to hashing specifications
+ * 
+ * @param   state  The state that should be initialised
+ * @param   spec   The specifications for the state
+ * @return         Zero on success, -1 on error
+ */
+int
+libkeccak_state_initialise(libkeccak_state_t *restrict state, const libkeccak_spec_t *restrict spec)
+{
+	long int x;
+	state->r = spec->bitrate;
+	state->n = spec->output;
+	state->c = spec->capacity;
+	state->b = state->r + state->c;
+	state->w = x = state->b / 25;
+	state->l = 0;
+	if (x & 0xF0L) state->l |= 4, x >>= 4;
+	if (x & 0x0CL) state->l |= 2, x >>= 2;
+	if (x & 0x02L) state->l |= 1;
+	state->nr = 12 + (state->l << 1);
+	state->wmod = (state->w == 64) ? ~0LL : (int64_t)((1ULL << state->w) - 1);
+	for (x = 0; x < 25; x++)
+		state->S[x] = 0;
+	state->mptr = 0;
+	state->mlen = (size_t)(state->r * state->b) >> 2;
+	state->M = malloc(state->mlen * sizeof(char));
+	return state->M == NULL ? -1 : 0;
+}