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authorMattias Andrée <maandree@kth.se>2022-02-26 14:09:49 +0100
committerMattias Andrée <maandree@kth.se>2022-02-26 19:11:06 +0100
commite2d8ba51ecd9a302641e63bf7aafbcddb8da1375 (patch)
tree49f027a6f62f46269fe43095c1197d97600a554a
parentFix error in libkeccak_degeneralise_spec: spec->state_size was set to 1 rather than have_state_size (diff)
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Fix libkeccak_degeneralise_spec and add missing error: LIBKECCAK_GENERALISED_SPEC_ERROR_STATE_BITRATE_CAPACITY_INCONSISTENCY
Signed-off-by: Mattias Andrée <maandree@kth.se>
-rw-r--r--libkeccak.h10
-rw-r--r--libkeccak_degeneralise_spec.34
-rw-r--r--libkeccak_degeneralise_spec.c34
3 files changed, 29 insertions, 19 deletions
diff --git a/libkeccak.h b/libkeccak.h
index 1244aec..932c5de 100644
--- a/libkeccak.h
+++ b/libkeccak.h
@@ -160,6 +160,14 @@
*/
#define LIBKECCAK_GENERALISED_SPEC_ERROR_OUTPUT_NONPOSITIVE 11
+/**
+ * Invalid `struct libkeccak_generalised_spec.state_size`,
+ * `struct libkeccak_generalised_spec.bitrate`, and
+ * `struct libkeccak_generalised_spec.capacity`:
+ * `.bitrate + .capacity != .state_size`
+ */
+#define LIBKECCAK_GENERALISED_SPEC_ERROR_STATE_BITRATE_CAPACITY_INCONSISTENCY 12
+
/**
* Data structure that describes the parameters
@@ -313,7 +321,7 @@ libkeccak_spec_rawshake(struct libkeccak_spec *spec, long int x, long int d)
}
/**
- * Fill in a `struct libkeccak_spec` for a SHAKEx hashing
+< * Fill in a `struct libkeccak_spec` for a SHAKEx hashing
*
* @param spec:struct libkeccak_spec * The specifications datastructure to fill in
* @param x:long The value of x in `SHAKEx`, half the capacity
diff --git a/libkeccak_degeneralise_spec.3 b/libkeccak_degeneralise_spec.3
index bed40c4..b4819b3 100644
--- a/libkeccak_degeneralise_spec.3
+++ b/libkeccak_degeneralise_spec.3
@@ -84,6 +84,10 @@ modulus 8, that is, it was not in whole bytes.
.TP
.B LIBKECCAK_GENERALISED_SPEC_ERROR_OUTPUT_NONPOSITIVE
The specified output size was non-positive.
+.TP
+.B LIBKECCAK_GENERALISED_SPEC_ERROR_STATE_BITRATE_CAPACITY_INCONSISTENCY
+The sum of the bitrate and the capacity does not equal
+the state size (25 times the word size).
.PP
Note that there may be more than one error. Only the first
detected is returned.
diff --git a/libkeccak_degeneralise_spec.c b/libkeccak_degeneralise_spec.c
index 7fc51aa..99c8e00 100644
--- a/libkeccak_degeneralise_spec.c
+++ b/libkeccak_degeneralise_spec.c
@@ -81,29 +81,27 @@ libkeccak_degeneralise_spec(struct libkeccak_generalised_spec *restrict spec, st
}
- if (!have_bitrate && !have_capacity && !have_output) {
- state_size = deft(state_size, 1600L);
- output = ((state_size << 5) / 100L + 7L) & ~0x07L;
- bitrate = output << 1;
- capacity = state_size - bitrate;
- output = output >= 8 ? output : 8;
- } else if (!have_bitrate && !have_capacity) {
- bitrate = 1024;
- capacity = 1600 - 1024;
- state_size = deft(state_size, bitrate + capacity);
- } else if (!have_bitrate) {
+ 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);
- bitrate = state_size - capacity;
- output = deft(output, capacity == 8 ? 8 : (capacity << 1));
- } else if (!have_capacity) {
+ bitrate = deft(bitrate, state_size - capacity);
+ capacity = deft(capacity, state_size - bitrate);
+ output = deft(output, capacity * 2L <= 8 ? 8 : capacity * 2L);
+ } else {
state_size = deft(state_size, 1600L);
+ output = deft(output, (state_size * 32L / 100L + 7L) & ~7L);
+ bitrate = 2L * output;
capacity = state_size - bitrate;
- output = deft(output, capacity == 8 ? 8 : (capacity << 1));
- } else {
- state_size = deft(state_size, bitrate + capacity);
- output = deft(output, capacity == 8 ? 8 : (capacity << 1));
+ 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;