Imported Upstream version 5.3.0

1 files changed, 433 insertions, 0 deletions

diff --git a/src/libstrongswan/plugins/bliss/bliss_huffman.c b/src/libstrongswan/plugins/bliss/bliss_huffman.c
new file mode 100644
index 000000000..647234fd8
--- /dev/null
+++ b/src/libstrongswan/plugins/bliss/bliss_huffman.c
@@ -0,0 +1,433 @@
+/*
+ * Copyright (C) 2014 Tobias Brunner
+ * Copyright (C) 2014 Andreas Steffen
+ * HSR Hochschule fuer Technik Rapperswil
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the
+ * Free Software Foundation; either version 2 of the License, or (at your
+ * option) any later version.  See <http://www.fsf.org/copyleft/gpl.txt>.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
+ * or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * for more details.
+ */
+
+#include "bliss_param_set.h"
+
+#include <library.h>
+
+#include <stdio.h>
+#include <math.h>
+
+typedef struct tuple_t tuple_t;
+
+struct tuple_t {
+	int8_t z1;
+	int8_t z2;
+	uint16_t index;
+	uint16_t bits;
+	uint32_t code;
+};
+
+typedef struct node_t node_t;
+
+struct node_t {
+	node_t *next;
+	node_t *l;
+	node_t *r;
+	tuple_t *tuple;
+	double p;
+	uint16_t depth;
+	uint16_t index;
+};
+
+static void print_node(node_t *node)
+{
+	if (node->tuple)
+	{
+		fprintf(stderr, "(%1d,%2d)", node->tuple->z1, node->tuple->z2);
+	}
+	else
+	{
+		fprintf(stderr, "      ");
+	}
+	fprintf(stderr, "  %18.16f\n", node->p);
+}
+
+static double code_node(node_t *node, int *index, uint8_t bits, uint32_t code)
+{
+	double code_length = 0;
+
+	node->index = (*index)++;
+
+	if (node->tuple)
+	{
+		node->tuple->code = code;
+		node->tuple->bits = bits;
+		code_length += node->p * bits;
+	}
+	if (node->l)
+	{
+		code_length += code_node(node->l, index, bits + 1, (code << 1));
+	}
+	if (node->r)
+	{
+		code_length += code_node(node->r, index, bits + 1, (code << 1) + 1);
+	}
+
+	return code_length;
+
+}
+
+static void write_node(node_t *node)
+{
+	int16_t node_0, node_1, tuple;
+
+	node_0 = node->l ? node->l->index : BLISS_HUFFMAN_CODE_NO_NODE;
+	node_1 = node->r ? node->r->index : BLISS_HUFFMAN_CODE_NO_NODE;
+	tuple = node->tuple ? node->tuple->index : BLISS_HUFFMAN_CODE_NO_TUPLE;
+
+	printf("\t{ %3d, %3d, %3d },  /* %3d: ", node_0, node_1, tuple, node->index);
+
+	if (node->tuple)
+	{
+		printf("(%d,%2d) %2u bit%s ", node->tuple->z1, node->tuple->z2,
+			   node->tuple->bits, (node->tuple->bits == 1) ? " " : "s");
+	}
+	printf("*/\n");
+
+	if (node->l)
+	{
+		write_node(node->l);
+	}
+	if (node->r)
+	{
+		write_node(node->r);
+	}
+}
+
+static void write_header(void)
+{
+	printf("/*\n");
+	printf(" * Copyright (C) 2014 Andreas Steffen\n");
+	printf(" * HSR Hochschule fuer Technik Rapperswil\n");
+	printf(" *\n");
+	printf(" * Optimum Huffman code for BLISS-X signatures\n");
+	printf(" *\n");
+	printf(" * This file has been automatically generated by the"
+		   " bliss_huffman utility\n");
+	printf(" * Do not edit manually!\n");
+	printf(" */\n\n");
+};
+
+static void write_code_tables(int bliss_type, int n_z1, int n_z2, node_t *nodes,
+							  tuple_t **tuples)
+{
+	int index, i, k;
+	uint32_t bit;
+	double code_length;
+
+	printf("#include \"bliss_huffman_code.h\"\n\n");
+
+	printf("static bliss_huffman_code_node_t nodes[] = {\n");
+	index = 0;
+	code_length = code_node(nodes, &index, 0, 0);
+	write_node(nodes);
+	printf("};\n\n");
+
+	printf("static bliss_huffman_code_tuple_t tuples[] = {\n");
+	index = 0;
+	for (i = 0; i < n_z1; i++)
+	{
+		if (i > 0)
+		{
+			printf("\n");
+		}
+		for (k = 1 - n_z2; k < n_z2; k++)
+		{
+			printf("\t{ %5u, %2u },  /* %3d: (%1d,%2d) ",
+						tuples[index]->code, tuples[index]->bits, index, i, k);
+			bit = 1 << (tuples[index]->bits - 1);
+			while (bit)
+			{
+				printf("%s", (tuples[index]->code & bit) ? "1" : "0");
+				bit >>= 1;
+			}
+			printf(" */\n");
+			index++;
+		}
+	}
+	printf("};\n\n");
+	printf("/* code_length = %6.4f bits/tuple (%d bits) */\n\n",
+			   code_length, (int)(512 * code_length + 1));
+
+	printf("bliss_huffman_code_t bliss_huffman_code_%d = {\n", bliss_type);
+	printf("\t.n_z1 = %d,\n", n_z1);
+	printf("\t.n_z2 = %d,\n", n_z2);
+	printf("\t.tuples = tuples,\n");
+	printf("\t.nodes  = nodes\n");
+	printf("};\n");
+}
+
+static void destroy_node(node_t *node)
+{
+	if (node->l)
+	{
+		destroy_node(node->l);
+	}
+	if (node->r)
+	{
+		destroy_node(node->r);
+	}
+	free(node->tuple);
+	free(node);
+}
+
+static void remove_node(node_t *list, node_t **last, node_t *node)
+{
+	node_t *current, *prev;
+
+	for (current = list->next, prev = list; current;
+		 prev = current, current = current->next)
+	{
+		if (current == node)
+		{
+			prev->next = current->next;
+			if (*last == current)
+			{
+				*last = prev->next ?: prev;
+			}
+			break;
+		}
+	}
+}
+
+/**
+ * Generate a Huffman code for the optimum encoding of BLISS signatures
+ */
+int main(int argc, char *argv[])
+{
+	bliss_param_set_t *set;
+	int dx, bliss_type, depth = 1, groups, groups_left, pairs = 1;
+	int i_max = 9, k_max = 8, index_max = (2*k_max - 1) * i_max;
+	int i, i_top, k, k_top;
+	uint16_t index;
+	double p, p_z1[i_max], p_z2[k_max], x_z1[i_max], x_z2[k_max];
+	double t, x, x0, p_sum, entropy = 0, erf_i, erf_k, erf_0 = 0;
+	tuple_t *tuple, *tuples[index_max];
+	node_t *node, *node_l, *node_r, *nodes = NULL;
+	node_t *node_list, *node_last;
+
+	if (argc < 2)
+	{
+		fprintf(stderr, "usage: bliss_huffman <bliss type> [<pairs>]\n");
+		exit(1);
+	}
+	if (argc > 2)
+	{
+		pairs = atoi(argv[2]);
+	}
+	fprintf(stderr, "%d code pairs with constant length\n\n", pairs);
+	groups_left = groups = pairs >> 1;
+
+	bliss_type = atoi(argv[1]);
+	set = bliss_param_set_get_by_id(bliss_type);
+	if (!set)
+	{
+		fprintf(stderr, "bliss type %d unsupported\n", bliss_type);
+		exit(1);
+	}
+	write_header();
+	printf("/*\n");
+	printf(" * Design: sigma = %u\n", set->sigma);
+	printf(" *\n");
+
+	t = 1/(sqrt(2) * set->sigma);
+
+	/* Probability distribution for z1 */
+	i_top = (set->B_inf + 255) / 256;
+	p_sum = 0;
+	x = 0;
+
+	for (i = 0; i < i_top; i++)
+	{
+		x = min(x + 256, set->B_inf);
+		erf_i = erf(t*x);
+		p_z1[i] = erf_i - erf_0;
+		p_sum += p_z1[i];
+		erf_0 = erf_i;
+		x_z1[i] = x;
+	}
+
+	/* Normalize and print the probability distribution for z1 */
+	printf(" *   i  p_z1[i]\n");
+	x0 = 0;
+
+	for (i = 0; i < i_top; i++)
+	{
+		p_z1[i] /= p_sum;
+		printf(" *  %2d  %18.16f      %4.0f .. %4.0f\n", i, p_z1[i], x0, x_z1[i]);
+		x0 = x_z1[i];
+	}
+	printf(" *\n");
+
+	/* Probability distribution for z2 */
+	dx = 1 << set->d;
+	k_top = 1 + set->B_inf / dx;
+	x = (dx >> 1) - 0.5;
+	p_sum = 0;
+
+	for (k = 0; k < k_top; k++)
+	{
+
+		erf_k = erf(t*x) / 2;
+		p_z2[k] = (k == 0) ? 2*erf_k : erf_k - erf_0;
+		p_sum +=  (k == 0) ? p_z2[k] : 2*p_z2[k];
+		erf_0 = erf_k;
+		x_z2[k] = x;
+		x += dx;
+	}
+
+	/* Normalize the probability distribution for z2 */
+	for (k = 0; k < k_top; k++)
+	{
+		p_z2[k] /= p_sum;
+	}
+
+	/* Print the probability distribution for z2 */
+	printf(" *   k  p_z2[k]  dx = %d\n", dx);
+
+	for (k = 1 - k_top; k < k_top; k++)
+	{
+
+		printf(" *  %2d  %18.16f  ",k, p_z2[abs(k)]);
+		if (k < 0)
+		{
+			printf(" %7.1f ..%7.1f\n", -x_z2[-k], -x_z2[-k-1]);
+		}
+		else if (k == 0)
+		{
+			printf(" %7.1f ..%7.1f\n", -x_z2[k], x_z2[k]);
+		}
+		else
+		{
+			printf(" %7.1f ..%7.1f\n", x_z2[k-1], x_z2[k]);
+		}
+	}
+	printf(" *\n");
+
+	/* Compute probabilities of tuples (z1, z2) */
+	INIT(node_list);
+	node_last = node_list;
+	printf(" *  (i, k)  p\n");
+	p_sum =0;
+	index = 0;
+
+	for (i = 0; i < i_top; i++)
+	{
+		for (k = 1 - k_top; k < k_top; k++)
+		{
+			p = p_z1[i] * p_z2[abs(k)];
+			printf(" *  (%1d,%2d)  %18.16f\n", i, k, p);
+			p_sum += p;
+			entropy += -log(p) * p;
+
+			INIT(tuple,
+				.z1 = i,
+				.z2 = k,
+				.index = index,
+			);
+			tuples[index++] = tuple;
+
+			INIT(node,
+				.p = p,
+				.tuple = tuple,
+			);
+			node_last->next = node;
+			node_last = node;
+		}
+		printf(" *\n");
+	}
+	entropy /= log(2);
+	printf(" *  p_sum   %18.16f\n", p_sum);
+	printf(" *\n");
+	printf(" * entropy = %6.4f bits/tuple (%d bits)\n",
+			   entropy, (int)(512 * entropy));
+	printf(" */\n\n");
+
+	/* Build Huffman tree */
+	while (node_list->next != node_last)
+	{
+		node_r = node_l = NULL;
+
+		for (node = node_list->next; node; node = node->next)
+		{
+			if (pairs > 0)
+			{
+				if (!node->tuple)
+				{
+					continue;
+				}
+			}
+			else if (groups_left > 0)
+			{
+				if (node->tuple || node->depth != depth)
+				{
+					continue;
+				}
+			}
+			if (node_r == NULL || node->p < node_r->p)
+			{
+				node_l = node_r;
+				node_r = node;
+			}
+			else if (node_l == NULL || node->p < node_l->p)
+			{
+				node_l = node;
+			}
+		}
+
+		INIT(node,
+			.l = node_l,
+			.r = node_r,
+			.p = node_l->p + node_r->p,
+			.depth = 1 + max(node_l->depth, node_r->depth),
+			.tuple = NULL,
+		);
+		print_node(node_r);
+		print_node(node_l);
+		fprintf(stderr, "        %18.16f", node->p);
+
+		remove_node(node_list, &node_last, node_l);
+		remove_node(node_list, &node_last, node_r);
+		node_last->next = node;
+		node_last = node;
+
+		if (pairs > 0)
+		{
+			pairs--;
+		}
+		else if (groups > 0)
+		{
+			if (--groups_left == 0)
+			{
+				groups >>= 1;
+				groups_left = groups;
+				depth++;
+			}
+		}
+		fprintf(stderr, "\n\n");
+	}
+
+
+	nodes = node_list->next;
+
+	write_code_tables(bliss_type, i_top, k_top, nodes, tuples);
+
+	destroy_node(nodes);
+	destroy_node(node_list);
+	exit(0);
+}
+