--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/ssl/libcrypto/src/crypto/bn/bn_ctx.c	Tue Feb 02 02:01:42 2010 +0200
@@ -0,0 +1,454 @@
+/* crypto/bn/bn_ctx.c */
+/* Written by Ulf Moeller for the OpenSSL project. */
+/* ====================================================================
+ * Copyright (c) 1998-2004 The OpenSSL Project.  All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer. 
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ *
+ * 3. All advertising materials mentioning features or use of this
+ *    software must display the following acknowledgment:
+ *    "This product includes software developed by the OpenSSL Project
+ *    for use in the OpenSSL Toolkit. (http://www.openssl.org/)"
+ *
+ * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
+ *    endorse or promote products derived from this software without
+ *    prior written permission. For written permission, please contact
+ *    openssl-core@openssl.org.
+ *
+ * 5. Products derived from this software may not be called "OpenSSL"
+ *    nor may "OpenSSL" appear in their names without prior written
+ *    permission of the OpenSSL Project.
+ *
+ * 6. Redistributions of any form whatsoever must retain the following
+ *    acknowledgment:
+ *    "This product includes software developed by the OpenSSL Project
+ *    for use in the OpenSSL Toolkit (http://www.openssl.org/)"
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
+ * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+ * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE OpenSSL PROJECT OR
+ * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
+ * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+ * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+ * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
+ * OF THE POSSIBILITY OF SUCH DAMAGE.
+ * ====================================================================
+ *
+ * This product includes cryptographic software written by Eric Young
+ * (eay@cryptsoft.com).  This product includes software written by Tim
+ * Hudson (tjh@cryptsoft.com).
+ *
+ */
+
+#if !defined(BN_CTX_DEBUG) && !defined(BN_DEBUG)
+#ifndef NDEBUG
+#define NDEBUG
+#endif
+#endif
+
+#include <stdio.h>
+#include <assert.h>
+
+#include "cryptlib.h"
+#include "bn_lcl.h"
+
+/* TODO list
+ *
+ * 1. Check a bunch of "(words+1)" type hacks in various bignum functions and
+ * check they can be safely removed.
+ *  - Check +1 and other ugliness in BN_from_montgomery()
+ *
+ * 2. Consider allowing a BN_new_ex() that, at least, lets you specify an
+ * appropriate 'block' size that will be honoured by bn_expand_internal() to
+ * prevent piddly little reallocations. OTOH, profiling bignum expansions in
+ * BN_CTX doesn't show this to be a big issue.
+ */
+
+/* How many bignums are in each "pool item"; */
+#define BN_CTX_POOL_SIZE	16
+/* The stack frame info is resizing, set a first-time expansion size; */
+#define BN_CTX_START_FRAMES	32
+
+/***********/
+/* BN_POOL */
+/***********/
+
+/* A bundle of bignums that can be linked with other bundles */
+typedef struct bignum_pool_item
+	{
+	/* The bignum values */
+	BIGNUM vals[BN_CTX_POOL_SIZE];
+	/* Linked-list admin */
+	struct bignum_pool_item *prev, *next;
+	} BN_POOL_ITEM;
+/* A linked-list of bignums grouped in bundles */
+typedef struct bignum_pool
+	{
+	/* Linked-list admin */
+	BN_POOL_ITEM *head, *current, *tail;
+	/* Stack depth and allocation size */
+	unsigned used, size;
+	} BN_POOL;
+static void		BN_POOL_init(BN_POOL *);
+static void		BN_POOL_finish(BN_POOL *);
+#ifndef OPENSSL_NO_DEPRECATED
+static void		BN_POOL_reset(BN_POOL *);
+#endif
+static BIGNUM *		BN_POOL_get(BN_POOL *);
+static void		BN_POOL_release(BN_POOL *, unsigned int);
+
+/************/
+/* BN_STACK */
+/************/
+
+/* A wrapper to manage the "stack frames" */
+typedef struct bignum_ctx_stack
+	{
+	/* Array of indexes into the bignum stack */
+	unsigned int *indexes;
+	/* Number of stack frames, and the size of the allocated array */
+	unsigned int depth, size;
+	} BN_STACK;
+static void		BN_STACK_init(BN_STACK *);
+static void		BN_STACK_finish(BN_STACK *);
+#ifndef OPENSSL_NO_DEPRECATED
+static void		BN_STACK_reset(BN_STACK *);
+#endif
+static int		BN_STACK_push(BN_STACK *, unsigned int);
+static unsigned int	BN_STACK_pop(BN_STACK *);
+
+/**********/
+/* BN_CTX */
+/**********/
+
+/* The opaque BN_CTX type */
+struct bignum_ctx
+	{
+	/* The bignum bundles */
+	BN_POOL pool;
+	/* The "stack frames", if you will */
+	BN_STACK stack;
+	/* The number of bignums currently assigned */
+	unsigned int used;
+	/* Depth of stack overflow */
+	int err_stack;
+	/* Block "gets" until an "end" (compatibility behaviour) */
+	int too_many;
+	};
+
+/* Enable this to find BN_CTX bugs */
+#ifdef BN_CTX_DEBUG
+static const char *ctxdbg_cur = NULL;
+static void ctxdbg(BN_CTX *ctx)
+	{
+	unsigned int bnidx = 0, fpidx = 0;
+	BN_POOL_ITEM *item = ctx->pool.head;
+	BN_STACK *stack = &ctx->stack;
+	fprintf(stderr,"(%08x): ", (unsigned int)ctx);
+	while(bnidx < ctx->used)
+		{
+		fprintf(stderr,"%02x ", item->vals[bnidx++ % BN_CTX_POOL_SIZE].dmax);
+		if(!(bnidx % BN_CTX_POOL_SIZE))
+			item = item->next;
+		}
+	fprintf(stderr,"\n");
+	bnidx = 0;
+	fprintf(stderr,"          : ");
+	while(fpidx < stack->depth)
+		{
+		while(bnidx++ < stack->indexes[fpidx])
+			fprintf(stderr,"   ");
+		fprintf(stderr,"^^ ");
+		bnidx++;
+		fpidx++;
+		}
+	fprintf(stderr,"\n");
+	}
+#define CTXDBG_ENTRY(str, ctx)	do { \
+				ctxdbg_cur = (str); \
+				fprintf(stderr,"Starting %s\n", ctxdbg_cur); \
+				ctxdbg(ctx); \
+				} while(0)
+#define CTXDBG_EXIT(ctx)	do { \
+				fprintf(stderr,"Ending %s\n", ctxdbg_cur); \
+				ctxdbg(ctx); \
+				} while(0)
+#define CTXDBG_RET(ctx,ret)
+#else
+#define CTXDBG_ENTRY(str, ctx)
+#define CTXDBG_EXIT(ctx)
+#define CTXDBG_RET(ctx,ret)
+#endif
+
+/* This function is an evil legacy and should not be used. This implementation
+ * is WYSIWYG, though I've done my best. */
+#ifndef OPENSSL_NO_DEPRECATED
+EXPORT_C void BN_CTX_init(BN_CTX *ctx)
+	{
+	/* Assume the caller obtained the context via BN_CTX_new() and so is
+	 * trying to reset it for use. Nothing else makes sense, least of all
+	 * binary compatibility from a time when they could declare a static
+	 * variable. */
+	BN_POOL_reset(&ctx->pool);
+	BN_STACK_reset(&ctx->stack);
+	ctx->used = 0;
+	ctx->err_stack = 0;
+	ctx->too_many = 0;
+	}
+#endif
+
+EXPORT_C BN_CTX *BN_CTX_new(void)
+	{
+	BN_CTX *ret = OPENSSL_malloc(sizeof(BN_CTX));
+	if(!ret)
+		{
+		BNerr(BN_F_BN_CTX_NEW,ERR_R_MALLOC_FAILURE);
+		return NULL;
+		}
+	/* Initialise the structure */
+	BN_POOL_init(&ret->pool);
+	BN_STACK_init(&ret->stack);
+	ret->used = 0;
+	ret->err_stack = 0;
+	ret->too_many = 0;
+	return ret;
+	}
+
+EXPORT_C void BN_CTX_free(BN_CTX *ctx)
+	{
+	if (ctx == NULL)
+		return;
+#ifdef BN_CTX_DEBUG
+	{
+	BN_POOL_ITEM *pool = ctx->pool.head;
+	fprintf(stderr,"BN_CTX_free, stack-size=%d, pool-bignums=%d\n",
+		ctx->stack.size, ctx->pool.size);
+	fprintf(stderr,"dmaxs: ");
+	while(pool) {
+		unsigned loop = 0;
+		while(loop < BN_CTX_POOL_SIZE)
+			fprintf(stderr,"%02x ", pool->vals[loop++].dmax);
+		pool = pool->next;
+	}
+	fprintf(stderr,"\n");
+	}
+#endif
+	BN_STACK_finish(&ctx->stack);
+	BN_POOL_finish(&ctx->pool);
+	OPENSSL_free(ctx);
+	}
+
+EXPORT_C void BN_CTX_start(BN_CTX *ctx)
+	{
+	CTXDBG_ENTRY("BN_CTX_start", ctx);
+	/* If we're already overflowing ... */
+	if(ctx->err_stack || ctx->too_many)
+		ctx->err_stack++;
+	/* (Try to) get a new frame pointer */
+	else if(!BN_STACK_push(&ctx->stack, ctx->used))
+		{
+		BNerr(BN_F_BN_CTX_START,BN_R_TOO_MANY_TEMPORARY_VARIABLES);
+		ctx->err_stack++;
+		}
+	CTXDBG_EXIT(ctx);
+	}
+
+EXPORT_C void BN_CTX_end(BN_CTX *ctx)
+	{
+	CTXDBG_ENTRY("BN_CTX_end", ctx);
+	if(ctx->err_stack)
+		ctx->err_stack--;
+	else
+		{
+		unsigned int fp = BN_STACK_pop(&ctx->stack);
+		/* Does this stack frame have anything to release? */
+		if(fp < ctx->used)
+			BN_POOL_release(&ctx->pool, ctx->used - fp);
+		ctx->used = fp;
+		/* Unjam "too_many" in case "get" had failed */
+		ctx->too_many = 0;
+		}
+	CTXDBG_EXIT(ctx);
+	}
+
+EXPORT_C BIGNUM *BN_CTX_get(BN_CTX *ctx)
+	{
+	BIGNUM *ret;
+	CTXDBG_ENTRY("BN_CTX_get", ctx);
+	if(ctx->err_stack || ctx->too_many) return NULL;
+	if((ret = BN_POOL_get(&ctx->pool)) == NULL)
+		{
+		/* Setting too_many prevents repeated "get" attempts from
+		 * cluttering the error stack. */
+		ctx->too_many = 1;
+		BNerr(BN_F_BN_CTX_GET,BN_R_TOO_MANY_TEMPORARY_VARIABLES);
+		return NULL;
+		}
+	/* OK, make sure the returned bignum is "zero" */
+	BN_zero(ret);
+	ctx->used++;
+	CTXDBG_RET(ctx, ret);
+	return ret;
+	}
+
+/************/
+/* BN_STACK */
+/************/
+
+static void BN_STACK_init(BN_STACK *st)
+	{
+	st->indexes = NULL;
+	st->depth = st->size = 0;
+	}
+
+static void BN_STACK_finish(BN_STACK *st)
+	{
+	if(st->size) OPENSSL_free(st->indexes);
+	}
+
+#ifndef OPENSSL_NO_DEPRECATED
+static void BN_STACK_reset(BN_STACK *st)
+	{
+	st->depth = 0;
+	}
+#endif
+
+static int BN_STACK_push(BN_STACK *st, unsigned int idx)
+	{
+	if(st->depth == st->size)
+		/* Need to expand */
+		{
+		unsigned int newsize = (st->size ?
+				(st->size * 3 / 2) : BN_CTX_START_FRAMES);
+		unsigned int *newitems = OPENSSL_malloc(newsize *
+						sizeof(unsigned int));
+		if(!newitems) return 0;
+		if(st->depth)
+			memcpy(newitems, st->indexes, st->depth *
+						sizeof(unsigned int));
+		if(st->size) OPENSSL_free(st->indexes);
+		st->indexes = newitems;
+		st->size = newsize;
+		}
+	st->indexes[(st->depth)++] = idx;
+	return 1;
+	}
+
+static unsigned int BN_STACK_pop(BN_STACK *st)
+	{
+	return st->indexes[--(st->depth)];
+	}
+
+/***********/
+/* BN_POOL */
+/***********/
+
+static void BN_POOL_init(BN_POOL *p)
+	{
+	p->head = p->current = p->tail = NULL;
+	p->used = p->size = 0;
+	}
+
+static void BN_POOL_finish(BN_POOL *p)
+	{
+	while(p->head)
+		{
+		unsigned int loop = 0;
+		BIGNUM *bn = p->head->vals;
+		while(loop++ < BN_CTX_POOL_SIZE)
+			{
+			if(bn->d) BN_clear_free(bn);
+			bn++;
+			}
+		p->current = p->head->next;
+		OPENSSL_free(p->head);
+		p->head = p->current;
+		}
+	}
+
+#ifndef OPENSSL_NO_DEPRECATED
+static void BN_POOL_reset(BN_POOL *p)
+	{
+	BN_POOL_ITEM *item = p->head;
+	while(item)
+		{
+		unsigned int loop = 0;
+		BIGNUM *bn = item->vals;
+		while(loop++ < BN_CTX_POOL_SIZE)
+			{
+			if(bn->d) BN_clear(bn);
+			bn++;
+			}
+		item = item->next;
+		}
+	p->current = p->head;
+	p->used = 0;
+	}
+#endif
+
+static BIGNUM *BN_POOL_get(BN_POOL *p)
+	{
+	if(p->used == p->size)
+		{
+		BIGNUM *bn;
+		unsigned int loop = 0;
+		BN_POOL_ITEM *item = OPENSSL_malloc(sizeof(BN_POOL_ITEM));
+		if(!item) return NULL;
+		/* Initialise the structure */
+		bn = item->vals;
+		while(loop++ < BN_CTX_POOL_SIZE)
+			BN_init(bn++);
+		item->prev = p->tail;
+		item->next = NULL;
+		/* Link it in */
+		if(!p->head)
+			p->head = p->current = p->tail = item;
+		else
+			{
+			p->tail->next = item;
+			p->tail = item;
+			p->current = item;
+			}
+		p->size += BN_CTX_POOL_SIZE;
+		p->used++;
+		/* Return the first bignum from the new pool */
+		return item->vals;
+		}
+	if(!p->used)
+		p->current = p->head;
+	else if((p->used % BN_CTX_POOL_SIZE) == 0)
+		p->current = p->current->next;
+	return p->current->vals + ((p->used++) % BN_CTX_POOL_SIZE);
+	}
+
+static void BN_POOL_release(BN_POOL *p, unsigned int num)
+	{
+	unsigned int offset = (p->used - 1) % BN_CTX_POOL_SIZE;
+	p->used -= num;
+	while(num--)
+		{
+		bn_check_top(p->current->vals + offset);
+		if(!offset)
+			{
+			offset = BN_CTX_POOL_SIZE - 1;
+			p->current = p->current->prev;
+			}
+		else
+			offset--;
+		}
+	}
+