Add support for Keccak, SHA3, SHAKE, and RawSHAKE via libkeccak>=1.3 (this version introduced zerocopy)

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

1 files changed, 148 insertions, 0 deletions

diff --git a/libhashsum_init_keccak__.c b/libhashsum_init_keccak__.c
new file mode 100644
index 0000000..b0023a5
--- /dev/null
+++ b/libhashsum_init_keccak__.c
@@ -0,0 +1,148 @@
+/* See LICENSE file for copyright and license details. */
+#include "common.h"
+#ifdef LIBHASHSUM_INCLUDE_LIBKECCAK_STATE
+
+
+LIBHASHSUM_1_NONNULL_
+static size_t
+process(struct libhashsum_hasher *this, const void *data, size_t bytes)
+{
+	bytes -= bytes % this->input_block_size;
+	libkeccak_zerocopy_update(&this->state.keccak.s, data, bytes);
+	return bytes;
+}
+
+
+LIBHASHSUM_1_NONNULL_
+static int
+finalise_const(struct libhashsum_hasher *this, const void *data, size_t bytes, unsigned extra_bits)
+{
+	const uint8_t *m = data;
+	size_t r;
+
+	if (extra_bits > 7U) {
+		errno = EINVAL;
+		return -1;
+	}
+
+	r = process(this, m, bytes);
+	m = &m[r];
+	bytes -= r;
+
+	if (this->hash_size > sizeof(this->state.keccak.sum.buf))
+		this->hash_output = this->state.keccak.sum.dyn;
+	else
+		this->hash_output = this->state.keccak.sum.buf;
+	libkeccak_digest(&this->state.keccak.s, m, bytes, extra_bits, this->state.keccak.suffix, this->hash_output);
+	libkeccak_state_wipe_message(&this->state.keccak.s);
+	libkeccak_state_fast_destroy(&this->state.keccak.s);
+	memset(&this->state.keccak.s, 0, sizeof(this->state.keccak.s));
+	this->state.keccak.s.M = NULL;
+	return 0;
+}
+
+
+LIBHASHSUM_1_NONNULL_
+static int
+finalise(struct libhashsum_hasher *this, void *data, size_t bytes, unsigned extra_bits, size_t size)
+{
+	uint8_t *m = data;
+	size_t r;
+	size_t need;
+
+	if (extra_bits > 7U) {
+		errno = EINVAL;
+		return -1;
+	}
+
+	r = process(this, m, bytes);
+	m = &m[r];
+	bytes -= r;
+	size -= r;
+
+	need = strlen(this->state.keccak.suffix) + 2U + extra_bits;
+	need = (need + 7U) >> 3;
+	need += bytes;
+	if (need & (this->input_block_size - 1U)) {
+		need &= ~(this->input_block_size - 1U);
+		need += this->input_block_size;
+	}
+
+	if (this->hash_size > sizeof(this->state.keccak.sum.buf))
+		this->hash_output = this->state.keccak.sum.dyn;
+	else
+		this->hash_output = this->state.keccak.sum.buf;
+	if (size < need)
+		libkeccak_digest(&this->state.keccak.s, m, bytes, extra_bits,
+		                 this->state.keccak.suffix, this->hash_output);
+	else
+		libkeccak_zerocopy_digest(&this->state.keccak.s, m, bytes, extra_bits,
+		                          this->state.keccak.suffix, this->hash_output);
+	libkeccak_state_wipe_message(&this->state.keccak.s);
+	libkeccak_state_fast_destroy(&this->state.keccak.s);
+	memset(&this->state.keccak.s, 0, sizeof(this->state.keccak.s));
+	this->state.keccak.s.M = NULL;
+	return 0;
+}
+
+
+LIBHASHSUM_1_NONNULL_
+static void
+destroy(struct libhashsum_hasher *this)
+{
+	libkeccak_state_wipe_message(&this->state.keccak.s);
+	libkeccak_state_fast_destroy(&this->state.keccak.s);
+	memset(&this->state.keccak.s, 0, sizeof(this->state.keccak.s));
+	this->state.keccak.s.M = NULL;
+	if (this->hash_size > sizeof(this->state.keccak.sum.buf)) {
+		free(this->state.keccak.sum.dyn);
+		this->state.keccak.sum.dyn = NULL;
+	}
+}
+
+
+int
+libhashsum_init_keccak__(struct libhashsum_hasher *this, size_t hashbits, void *spec_, const char *suffix)
+{
+	struct libkeccak_spec *spec = spec_;
+
+	this->hash_size = hashbits >> 3;
+	this->hash_size += (size_t)!!(hashbits & 7U);
+	this->hash_output = NULL;
+	this->supports_non_whole_bytes = 1;
+	this->state.keccak.suffix = suffix;
+
+	if (this->hash_size > sizeof(this->state.keccak.sum.buf)) {
+		this->state.keccak.sum.dyn = malloc(this->hash_size);
+		if (!this->state.keccak.sum.dyn)
+			return -1;
+	}
+
+	if (libkeccak_state_initialise(&this->state.keccak.s, spec)) {
+		if (this->hash_size > sizeof(this->state.keccak.sum.buf)) {
+			free(this->state.keccak.sum.dyn);
+			this->state.keccak.sum.dyn = NULL;
+		}
+		return -1;
+	}
+
+	this->input_block_size = libkeccak_zerocopy_chunksize(&this->state.keccak.s);
+	this->process = &process;
+	this->finalise_const = &finalise_const;
+	this->finalise = &finalise;
+	this->destroy = &destroy;
+	return 0;
+}
+
+
+#else
+int
+libhashsum_init_keccak__(struct libhashsum_hasher *this, size_t hashbits, void *spec, const char *suffix);
+{
+	(void) this;
+	(void) spec;
+	(void) suffix;
+	errno = ENOSYS;
+	return -1;
+}
+#endif