1 files changed, 315 insertions, 0 deletions

diff --git a/src/crypto/bn/ctx.c b/src/crypto/bn/ctx.c
new file mode 100644
index 0000000..e54007b
--- /dev/null
+++ b/src/crypto/bn/ctx.c
@@ -0,0 +1,315 @@
+/* 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). */
+
+
+#include <openssl/bn.h>
+
+#include <string.h>
+
+#include <openssl/err.h>
+#include <openssl/mem.h>
+
+
+/* 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
+
+/* 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;
+
+
+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 *);
+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 *);
+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;
+};
+
+BN_CTX *BN_CTX_new(void) {
+  BN_CTX *ret = OPENSSL_malloc(sizeof(BN_CTX));
+  if (!ret) {
+    OPENSSL_PUT_ERROR(BN, 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;
+}
+
+void BN_CTX_free(BN_CTX *ctx) {
+  if (ctx == NULL) {
+    return;
+  }
+
+  BN_STACK_finish(&ctx->stack);
+  BN_POOL_finish(&ctx->pool);
+  OPENSSL_free(ctx);
+}
+
+void BN_CTX_start(BN_CTX *ctx) {
+  /* If we're already overflowing ... */
+  if (ctx->err_stack || ctx->too_many) {
+    ctx->err_stack++;
+  } else if (!BN_STACK_push(&ctx->stack, ctx->used)) {
+    /* (Try to) get a new frame pointer */
+    OPENSSL_PUT_ERROR(BN, BN_CTX_start, BN_R_TOO_MANY_TEMPORARY_VARIABLES);
+    ctx->err_stack++;
+  }
+}
+
+BIGNUM *BN_CTX_get(BN_CTX *ctx) {
+  BIGNUM *ret;
+  if (ctx->err_stack || ctx->too_many) {
+    return NULL;
+  }
+
+  ret = BN_POOL_get(&ctx->pool);
+  if (ret == NULL) {
+    /* Setting too_many prevents repeated "get" attempts from
+     * cluttering the error stack. */
+    ctx->too_many = 1;
+    OPENSSL_PUT_ERROR(BN, BN_CTX_get, BN_R_TOO_MANY_TEMPORARY_VARIABLES);
+    return NULL;
+  }
+
+  /* OK, make sure the returned bignum is "zero" */
+  BN_zero(ret);
+  ctx->used++;
+  return ret;
+}
+
+void BN_CTX_end(BN_CTX *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;
+  }
+}
+
+/************/
+/* 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);
+}
+
+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)];
+}
+
+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;
+  }
+}
+
+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--) {
+    if (!offset) {
+      offset = BN_CTX_POOL_SIZE - 1;
+      p->current = p->current->prev;
+    } else {
+      offset--;
+    }
+  }
+}