Add rpc_hash.c. Convert dynamic allocator in hash.c to use private

pool of pre-configured state blocks, suitable for an embedded system.

1 files changed, 300 insertions, 0 deletions

diff --git a/rpc_hash.c b/rpc_hash.c
new file mode 100644
index 0000000..4ceadb6
--- /dev/null
+++ b/rpc_hash.c
@@ -0,0 +1,300 @@
+/*
+ * rpc_hash.c
+ * ----------
+ * Remote procedure call server-side hash implementation.
+ *
+ * Authors: Rob Austein
+ * Copyright (c) 2015, NORDUnet A/S All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ * - Redistributions of source code must retain the above copyright notice,
+ *   this list of conditions and the following disclaimer.
+ *
+ * - 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.
+ *
+ * - Neither the name of the NORDUnet nor the names of its contributors may
+ *   be used to endorse or promote products derived from this software
+ *   without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
+ * IS" AND ANY EXPRESS 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 COPYRIGHT
+ * HOLDER OR 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.
+ */
+
+#include <string.h>
+
+#include "hal.h"
+#include "rpc_internal.h"
+
+/*
+ * Need table and handle allocation, including some kind of in_use
+ * flag (perhaps just handle == none).
+ *
+ * Hash and HMAC aren't really things for which we need permission
+ * bits, so not sure we even care about login stuff here.
+ */
+
+typedef struct {
+  hal_rpc_client_handle_t client_handle;
+  hal_rpc_session_handle_t session_handle;
+  hal_rpc_hash_handle_t hash_handle;
+  union {
+    hal_hash_state_t *hash;
+    hal_hmac_state_t *hmac;
+  } state;
+} handle_slot_t;
+
+#ifndef	HAL_STATIC_HASH_STATE_BLOCKS
+#define	HAL_STATIC_HASH_STATE_BLOCKS 0
+#endif
+
+#ifndef	HAL_STATIC_HMAC_STATE_BLOCKS
+#define	HAL_STATIC_HMAC_STATE_BLOCKS 0
+#endif
+
+#if HAL_STATIC_HASH_STATE_BLOCKS > 0
+static handle_slot_t hash_handle[HAL_STATIC_HASH_STATE_BLOCKS];
+#endif
+
+#if HAL_STATIC_HMAC_STATE_BLOCKS > 0
+static handle_slot_t hmac_handle[HAL_STATIC_HMAC_STATE_BLOCKS];
+#endif
+
+/*
+ * Handle allocation is simple: we look for an unused (state == NULL)
+ * slot in the appropriate table, and, assuming we find one, construct
+ * a composite handle consisting of a flag telling us which table this
+ * is, the index into the table, and a counter whose sole purpose is
+ * to keep the same handle from reoccurring anytime soon, to help
+ * identify use-after-free bugs in calling code.
+ */
+
+#define	HANDLE_FLAG_HMAC	0x80000000
+
+static inline handle_slot_t *alloc_handle(const int is_hmac)
+{
+#if HAL_STATIC_HASH_STATE_BLOCKS > 0 || HAL_STATIC_HMAC_STATE_BLOCKS > 0
+  static uint16_t next_glop = 0;
+  uint32_t glop = ++next_glop << 16;
+  next_glop %= 0x7FFF;
+#endif
+
+#if HAL_STATIC_HASH_STATE_BLOCKS > 0
+  if (!is_hmac) {
+    for (int i = 0; i < sizeof(hash_handle)/sizeof(*hash_handle); i++) {
+      if (hash_handle[i].state.hash == NULL) {
+        hash_handle[i].hash_handle.handle = i | glop;
+        return &hash_handle[i];
+      }
+    }
+  }
+#endif
+
+#if HAL_STATIC_HMAC_STATE_BLOCKS > 0
+  if (is_hmac) {
+    for (int i = 0; i < sizeof(hmac_handle)/sizeof(*hmac_handle); i++) {
+      if (hmac_handle[i].state.hmac == NULL) {
+        hmac_handle[i].hash_handle.handle = i | glop | HANDLE_FLAG_HMAC;
+        return &hmac_handle[i];
+      }
+    }
+  }
+#endif
+
+  return NULL;
+}
+
+/*
+ * Check a caller-supplied handle.  Must be in range, in use, and have
+ * the right glop.  Returns slot pointer on success, NULL otherwise.
+ */
+
+static inline handle_slot_t *find_handle(const hal_rpc_hash_handle_t handle)
+{
+#if HAL_STATIC_HASH_STATE_BLOCKS > 0 || HAL_STATIC_HMAC_STATE_BLOCKS > 0
+  const int i = (int) (handle.handle & 0xFFFF);
+  const int is_hmac = (handle.handle & HANDLE_FLAG_HMAC) != 0;
+#endif
+
+#if HAL_STATIC_HASH_STATE_BLOCKS > 0
+  if (!is_hmac && i < sizeof(hash_handle)/sizeof(*hash_handle) &&
+      hash_handle[i].hash_handle.handle == handle.handle && hash_handle[i].state.hash != NULL)
+    return &hash_handle[i];
+#endif
+
+#if HAL_STATIC_HASH_STATE_BLOCKS > 0
+  if (is_hmac && i < sizeof(hmac_handle)/sizeof(*hmac_handle) &&
+      hmac_handle[i].hash_handle.handle == handle.handle && hmac_handle[i].state.hmac != NULL)
+    return &hmac_handle[i];
+#endif
+
+  return NULL;
+}
+
+/*
+ * Translate an algorithm number to a descriptor.
+ */
+
+static inline const hal_hash_descriptor_t *alg_to_descriptor(const hal_digest_algorithm_t alg)
+{
+  switch (alg) {
+  case hal_digest_algorithm_sha1:       return hal_hash_sha1;
+  case hal_digest_algorithm_sha256:     return hal_hash_sha256;
+  case hal_digest_algorithm_sha512_224: return hal_hash_sha512_224;
+  case hal_digest_algorithm_sha512_256: return hal_hash_sha512_256;
+  case hal_digest_algorithm_sha384:     return hal_hash_sha384;
+  case hal_digest_algorithm_sha512:     return hal_hash_sha512;
+  default:                              return NULL;
+  }
+}
+
+/*
+ * Given a slot pointer, fetch the descriptor.
+ */
+
+static inline const hal_hash_descriptor_t *slot_to_descriptor(const handle_slot_t * const slot)
+{
+  if (slot == NULL)
+    return NULL;
+
+  if ((slot->hash_handle.handle & HANDLE_FLAG_HMAC) == 0)
+    return hal_hash_get_descriptor(slot->state.hash);
+  else
+    return hal_hmac_get_descriptor(slot->state.hmac);
+}
+
+/*
+ * Public API
+ */
+
+static hal_error_t get_digest_length(const hal_digest_algorithm_t alg, size_t *length)
+{
+  const hal_hash_descriptor_t * const d = alg_to_descriptor(alg);
+
+  if (d == NULL || length == NULL)
+    return HAL_ERROR_BAD_ARGUMENTS;
+
+  *length = d->digest_length;
+  return HAL_OK;
+}
+
+static hal_error_t get_digest_algorithm_id(const hal_digest_algorithm_t alg,
+                                           uint8_t *id, size_t *len, const size_t len_max)
+{
+  const hal_hash_descriptor_t * const d = alg_to_descriptor(alg);
+
+  if (d == NULL)
+    return HAL_ERROR_BAD_ARGUMENTS;
+
+  if (len != NULL)
+    *len = d->digest_algorithm_id_length;
+
+  if (id == NULL)
+    return HAL_OK;
+
+  if (len_max < d->digest_algorithm_id_length)
+    return HAL_ERROR_RESULT_TOO_LONG;
+
+  memcpy(id, d->digest_algorithm_id, d->digest_algorithm_id_length);
+  return HAL_OK;
+}
+
+static hal_error_t get_algorithm(const hal_rpc_hash_handle_t handle, hal_digest_algorithm_t *alg)
+{
+  handle_slot_t *slot = find_handle(handle);
+  const hal_hash_descriptor_t *descriptor = slot_to_descriptor(slot);
+
+  if (slot == NULL || alg == NULL)
+    return HAL_ERROR_BAD_ARGUMENTS;
+
+  if (descriptor == NULL)
+    return HAL_ERROR_IMPOSSIBLE;
+
+  *alg = descriptor->digest_algorithm;
+  return HAL_OK;
+}
+
+static hal_error_t initialize(const hal_rpc_client_handle_t client,
+                       const hal_rpc_session_handle_t session,
+                       hal_rpc_hash_handle_t *hash,
+                       const hal_digest_algorithm_t alg,
+                       const uint8_t * const key, const size_t key_len)
+{
+  const hal_hash_descriptor_t *descriptor;
+  handle_slot_t *slot;
+
+  if (hash == NULL)
+    return HAL_ERROR_BAD_ARGUMENTS;
+
+  if ((descriptor = alg_to_descriptor(alg)) == NULL)
+    return HAL_ERROR_BAD_ARGUMENTS;
+
+  if ((slot = alloc_handle(key != NULL)) == NULL)
+    return HAL_ERROR_ALLOCATION_FAILURE;
+
+  slot->client_handle  = client;
+  slot->session_handle = session;
+
+  if (key == NULL)
+    return hal_hash_initialize(NULL, descriptor, &slot->state.hash, NULL, 0);
+  else
+    return hal_hmac_initialize(NULL, descriptor, &slot->state.hmac, NULL, 0, key, key_len);
+}
+
+static hal_error_t update(const hal_rpc_hash_handle_t handle,
+                   const uint8_t * data, const size_t length)
+{
+  handle_slot_t *slot = find_handle(handle);
+
+  if (slot == NULL)
+    return HAL_ERROR_BAD_ARGUMENTS;
+
+  if ((handle.handle & HANDLE_FLAG_HMAC) == 0)
+    return hal_hash_update(slot->state.hash, data, length);
+  else
+    return hal_hmac_update(slot->state.hmac, data, length);
+}
+
+static hal_error_t finalize(const hal_rpc_hash_handle_t handle,
+                            uint8_t *digest, const size_t length)
+{
+  handle_slot_t *slot = find_handle(handle);
+  hal_error_t err;
+
+  if (slot == NULL)
+    return HAL_ERROR_BAD_ARGUMENTS;
+
+  if ((handle.handle & HANDLE_FLAG_HMAC) == 0) {
+    err = hal_hash_finalize(slot->state.hash, digest, length);
+    hal_hash_cleanup(&slot->state.hash);
+  }
+
+  else {
+    err = hal_hmac_finalize(slot->state.hmac, digest, length);
+    hal_hmac_cleanup(&slot->state.hmac);
+  }
+
+  return err;
+}
+
+const hal_rpc_hash_dispatch_t hal_rpc_remote_hash_dispatch = {
+  get_digest_length, get_digest_algorithm_id, get_algorithm, initialize, update, finalize
+};
+
+/*
+ * Local variables:
+ * indent-tabs-mode: nil
+ * End:
+ */