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, 75 insertions, 0 deletions

diff --git a/libhashsum_init_keccak_hasher.c b/libhashsum_init_keccak_hasher.c
new file mode 100644
index 0000000..93622f6
--- /dev/null
+++ b/libhashsum_init_keccak_hasher.c
@@ -0,0 +1,75 @@
+/* See LICENSE file for copyright and license details. */
+#include "common.h"
+#ifdef SUPPORT_KECCAK
+
+
+int
+libhashsum_init_keccak_hasher(struct libhashsum_hasher *this, size_t ratebits, size_t capbits, size_t hashbits)
+{
+	struct libkeccak_generalised_spec gspec;
+	struct libkeccak_spec spec;
+
+	if ((ratebits | capbits | hashbits) > (size_t)LONG_MAX) {
+		errno = EINVAL;
+		return -1;
+	} else if (!ratebits || !capbits || !hashbits) {
+		libkeccak_generalised_spec_initialise(&gspec);
+		if (ratebits)
+			gspec.bitrate = (long int)ratebits;
+		if (capbits)
+			gspec.capacity = (long int)capbits;
+		if (hashbits)
+			gspec.output = (long int)hashbits;
+		if (libkeccak_degeneralise_spec(&gspec, &spec)) {
+			errno = EINVAL;
+			return -1;
+		}
+		ratebits = (size_t)spec.bitrate;
+		capbits = (size_t)spec.capacity;
+		hashbits = (size_t)spec.output;
+	} else {
+		spec.bitrate = (long int)ratebits;
+		spec.capacity = (long int)capbits;
+		spec.output = (long int)hashbits;
+	}
+	if (libkeccak_spec_check(&spec)) {
+		errno = EINVAL;
+		return -1;
+	}
+
+	this->algorithm = LIBHASHSUM_KECCAK;
+	if ((capbits >> 1) == hashbits && !(capbits & 1U) &&
+	    1600U >= capbits && ratebits == 1600U - capbits) {
+		if (hashbits == 224U) {
+			this->algorithm = LIBHASHSUM_KECCAK_224;
+			this->algorithm_string = "Keccak-224";
+		} else if (hashbits == 256U) {
+			this->algorithm = LIBHASHSUM_KECCAK_256;
+			this->algorithm_string = "Keccak-256";
+		} else if (hashbits == 384U) {
+			this->algorithm = LIBHASHSUM_KECCAK_384;
+			this->algorithm_string = "Keccak-384";
+		} else if (hashbits == 512U) {
+			this->algorithm = LIBHASHSUM_KECCAK_512;
+			this->algorithm_string = "Keccak-512";
+		}
+	}
+	if (this->algorithm == LIBHASHSUM_KECCAK) {
+		sprintf(this->state.keccak.algostr, "Keccak[r=%zu,c=%zu,n=%zu]", ratebits, capbits, hashbits);
+		this->algorithm_string = this->state.keccak.algostr;
+	}
+
+	return libhashsum_init_keccak__(this, hashbits, &spec, "");
+}
+
+
+#else
+int
+libhashsum_init_keccak_hasher(struct libhashsum_hasher *this, size_t hashbits)
+{
+	(void) this;
+	(void) hashbits;
+	errno = ENOSYS;
+	return -1;
+}
+#endif