Organise files

Signed-off-by: Mattias Andrée <maandree@kth.se>

1 files changed, 120 insertions, 0 deletions

diff --git a/spec/libkeccak_degeneralise_spec.c b/spec/libkeccak_degeneralise_spec.c
new file mode 100644
index 0000000..2a719e9
--- /dev/null
+++ b/spec/libkeccak_degeneralise_spec.c
@@ -0,0 +1,120 @@
+/* See LICENSE file for copyright and license details. */
+#include "../common.h"
+
+
+#if defined(__clang__)
+# pragma clang diagnostic push
+# pragma clang diagnostic ignored "-Wconditional-uninitialized"
+#elif defined(__GNUC__)
+# pragma GCC diagnostic push
+# pragma GCC diagnostic ignored "-Wmaybe-uninitialized"
+#endif
+
+#define deft(v, dv) (have_##v ? v : (dv))
+
+
+/**
+ * Convert a `struct libkeccak_generalised_spec` to a `struct libkeccak_spec`
+ *
+ * If you are interrested in finding errors, you should call
+ * `libkeccak_spec_check(output)` if this function returns zero
+ * 
+ * @param   spec         The generalised input specifications, will be update with resolved automatic values
+ * @param   output_spec  The specification datastructure to fill in
+ * @return               Zero if `spec` is valid, a `LIBKECCAK_GENERALISED_SPEC_ERROR_*` if an error was found
+ */
+int
+libkeccak_degeneralise_spec(struct libkeccak_generalised_spec *restrict spec, struct libkeccak_spec *restrict output_spec)
+{
+	long int state_size, word_size, capacity, bitrate, output;
+	int have_state_size = spec->state_size != LIBKECCAK_GENERALISED_SPEC_AUTOMATIC;
+	int have_word_size  = spec->word_size  != LIBKECCAK_GENERALISED_SPEC_AUTOMATIC;
+	int have_capacity   = spec->capacity   != LIBKECCAK_GENERALISED_SPEC_AUTOMATIC;
+	int have_bitrate    = spec->bitrate    != LIBKECCAK_GENERALISED_SPEC_AUTOMATIC;
+	int have_output     = spec->output     != LIBKECCAK_GENERALISED_SPEC_AUTOMATIC;
+
+
+	if (have_state_size) {
+		state_size = spec->state_size;
+		if (state_size <= 0)
+			return LIBKECCAK_GENERALISED_SPEC_ERROR_STATE_NONPOSITIVE;
+		if (state_size > 1600)
+			return LIBKECCAK_GENERALISED_SPEC_ERROR_STATE_TOO_LARGE;
+		if (state_size % 25)
+			return LIBKECCAK_GENERALISED_SPEC_ERROR_STATE_MOD_25;
+	}
+
+	if (have_word_size) {
+		word_size = spec->word_size;
+		if (word_size <= 0)
+			return LIBKECCAK_GENERALISED_SPEC_ERROR_WORD_NONPOSITIVE;
+		if (word_size > 64)
+			return LIBKECCAK_GENERALISED_SPEC_ERROR_WORD_TOO_LARGE;		
+		if (have_state_size && state_size != word_size * 25)
+			return LIBKECCAK_GENERALISED_SPEC_ERROR_STATE_WORD_INCOHERENCY;
+		else if (!have_state_size) {
+			have_state_size = 1;
+			state_size = word_size * 25;
+		}
+	}
+
+	if (have_capacity) {
+		capacity = spec->capacity;
+		if (capacity <= 0)
+			return LIBKECCAK_GENERALISED_SPEC_ERROR_CAPACITY_NONPOSITIVE;
+		if (capacity & 7)
+			return LIBKECCAK_GENERALISED_SPEC_ERROR_CAPACITY_MOD_8;
+	}
+
+	if (have_bitrate) {
+		bitrate = spec->bitrate;
+		if (bitrate <= 0)
+			return LIBKECCAK_GENERALISED_SPEC_ERROR_BITRATE_NONPOSITIVE;
+		if (bitrate & 7)
+			return LIBKECCAK_GENERALISED_SPEC_ERROR_BITRATE_MOD_8;
+	}
+
+	if (have_output) {
+		output = spec->output;
+		if (output <= 0)
+			return LIBKECCAK_GENERALISED_SPEC_ERROR_OUTPUT_NONPOSITIVE;
+	}
+
+
+	if (have_bitrate + have_capacity == 2) {
+		if (!have_state_size) {
+			state_size = bitrate + capacity;
+			output = deft(output, capacity * 2L <= 8 ? 8 : capacity * 2L);
+		} else if (state_size != bitrate + capacity) {
+			return LIBKECCAK_GENERALISED_SPEC_ERROR_STATE_BITRATE_CAPACITY_INCONSISTENCY;
+		}
+	} else if (have_bitrate + have_capacity == 1) {
+		state_size = deft(state_size, 1600L);
+		capacity = deft(capacity, state_size - bitrate);
+		bitrate = deft(bitrate, state_size - capacity);
+		output = deft(output, capacity * 2L <= 8 ? 8 : capacity * 2L);
+	} else {
+		state_size = deft(state_size, 1600L);
+		capacity = state_size * 9 / 25;
+		bitrate = state_size - capacity;
+		output = deft(output, bitrate / 2L <= 8 ? 8 : bitrate / 2L);
+	}
+
+
+	spec->capacity   = output_spec->capacity = capacity;
+	spec->bitrate    = output_spec->bitrate  = bitrate;
+	spec->output     = output_spec->output   = output;
+	spec->state_size = state_size;
+	spec->word_size  = state_size / 25;
+
+	return 0;
+}
+
+
+#undef deft
+
+#if defined(__clang__)
+# pragma clang diagnostic pop
+#elif defined(__GNUC__)
+# pragma GCC diagnostic pop
+#endif