+/* 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;
+};
+
+/* Debugging functionality */
+static void ctxdbg(BIO *channel, const char *text, BN_CTX *ctx)
+{
+ unsigned int bnidx = 0, fpidx = 0;
+ BN_POOL_ITEM *item = ctx->pool.head;
+ BN_STACK *stack = &ctx->stack;
+
+ BIO_printf(channel, "%s\n", text);
+ BIO_printf(channel, " (%16p): ", (void*)ctx);
+ while (bnidx < ctx->used) {
+ BIO_printf(channel, "%03x ",
+ item->vals[bnidx++ % BN_CTX_POOL_SIZE].dmax);
+ if (!(bnidx % BN_CTX_POOL_SIZE))
+ item = item->next;
+ }
+ BIO_printf(channel, "\n");
+ bnidx = 0;
+ BIO_printf(channel, " %16s : ", "");
+ while (fpidx < stack->depth) {
+ while (bnidx++ < stack->indexes[fpidx])
+ BIO_printf(channel, " ");
+ BIO_printf(channel, "^^^ ");
+ bnidx++;
+ fpidx++;
+ }
+ BIO_printf(channel, "\n");
+}
+
+#define CTXDBG(str, ctx) \
+ OSSL_TRACE_BEGIN(BN_CTX) { \
+ ctxdbg(trc_out, str, ctx); \
+ } OSSL_TRACE_END(BN_CTX)