1 files changed, 353 insertions, 0 deletions
diff --git a/openssl-1.1.0h/crypto/bn/bn_ctx.c b/openssl-1.1.0h/crypto/bn/bn_ctx.c
new file mode 100644
index 0000000..68c0468
--- /dev/null
+++ b/openssl-1.1.0h/crypto/bn/bn_ctx.c
@@ -0,0 +1,353 @@
+/*
+ * Copyright 2000-2016 The OpenSSL Project Authors. All Rights Reserved.
+ *
+ * Licensed under the OpenSSL license (the "License").  You may not use
+ * this file except in compliance with the License.  You can obtain a copy
+ * in the file LICENSE in the source distribution or at
+ * https://www.openssl.org/source/license.html
+ */
+
+#include "internal/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 *);
+static BIGNUM *BN_POOL_get(BN_POOL *, int);
+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;
+    /* Flags. */
+    int flags;
+};
+
+/* 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, "(%16p): ", ctx);
+    while (bnidx < ctx->used) {
+        fprintf(stderr, "%03x ", 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
+
+
+BN_CTX *BN_CTX_new(void)
+{
+    BN_CTX *ret;
+
+    if ((ret = OPENSSL_zalloc(sizeof(*ret))) == NULL) {
+        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);
+    return ret;
+}
+
+BN_CTX *BN_CTX_secure_new(void)
+{
+    BN_CTX *ret = BN_CTX_new();
+
+    if (ret != NULL)
+        ret->flags = BN_FLG_SECURE;
+    return ret;
+}
+
+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);
+}
+
+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);
+}
+
+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);
+}
+
+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, ctx->flags)) == 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)
+{
+    OPENSSL_free(st->indexes);
+    st->indexes = NULL;
+}
+
+
+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(sizeof(*newitems) * newsize);
+        if (newitems == NULL)
+            return 0;
+        if (st->depth)
+            memcpy(newitems, st->indexes, sizeof(*newitems) * st->depth);
+        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)
+{
+    unsigned int loop;
+    BIGNUM *bn;
+
+    while (p->head) {
+        for (loop = 0, bn = p->head->vals; loop++ < BN_CTX_POOL_SIZE; bn++)
+            if (bn->d)
+                BN_clear_free(bn);
+        p->current = p->head->next;
+        OPENSSL_free(p->head);
+        p->head = p->current;
+    }
+}
+
+
+static BIGNUM *BN_POOL_get(BN_POOL *p, int flag)
+{
+    BIGNUM *bn;
+    unsigned int loop;
+
+    /* Full; allocate a new pool item and link it in. */
+    if (p->used == p->size) {
+        BN_POOL_ITEM *item = OPENSSL_malloc(sizeof(*item));
+        if (item == NULL)
+            return NULL;
+        for (loop = 0, bn = item->vals; loop++ < BN_CTX_POOL_SIZE; bn++) {
+            bn_init(bn);
+            if ((flag & BN_FLG_SECURE) != 0)
+                BN_set_flags(bn, BN_FLG_SECURE);
+        }
+        item->prev = p->tail;
+        item->next = NULL;
+
+        if (p->head == NULL)
+            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 == 0) {
+            offset = BN_CTX_POOL_SIZE - 1;
+            p->current = p->current->prev;
+        } else
+            offset--;
+    }
+}