hbcrypto hash-{init,update,final} for incremental hashing

[chiark-tcl.git] / crypto / hash.c

diff --git a/crypto/hash.c b/crypto/hash.c
new file mode 100644 (file)
index 0000000..7c53b01
--- /dev/null
+++ b/crypto/hash.c
@@ -0,0 +1,91 @@
+/*
+ * crypto - Tcl bindings for parts of the `nettle' crypto library
+ * Copyright 2006 Ian Jackson
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of the
+ * License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
+ * 02110-1301, USA.
+ */
+
+
+#include "chiark_tcl_crypto.h"
+
+typedef struct {
+  int ix;
+  const HashAlgInfo *alg;
+  Byte d[1];
+} HashState;
+
+int cht_do_hbcrypto_hash(ClientData cd, Tcl_Interp *ip, const HashAlgInfo *alg,
+                  HBytes_Value message, HBytes_Value *result) {
+  Byte *dest;
+
+  dest= cht_hb_arrayspace(result,alg->hashsize);
+  alg->oneshot(dest, cht_hb_data(&message), cht_hb_len(&message));
+  return TCL_OK;
+}
+
+int cht_do_hbcrypto_hash_init(ClientData cd, Tcl_Interp *ip,
+                             const HashAlgInfo *alg, void **state_r) {
+  HashState *state= TALLOC(sizeof(*state) + alg->statesize - 1);
+  state->ix= -1;
+  state->alg= alg;
+  alg->init(state->d);
+  *state_r= state;
+  return TCL_OK;
+}
+
+int cht_do_hbcrypto_hash_update(ClientData cd, Tcl_Interp *ip,
+                               void *state_v, HBytes_Value data) {
+  HashState *state= state_v;
+  state->alg->update(&state->d, cht_hb_data(&data), cht_hb_len(&data));
+  return TCL_OK;
+}
+
+int cht_do_hbcrypto_hash_final(ClientData cd, Tcl_Interp *ip,
+                              void *state_v, HBytes_Value *result) {
+  HashState *state= state_v;
+  Byte *digest;
+
+  digest= cht_hb_arrayspace(result,state->alg->hashsize);
+  state->alg->final(&state->d, digest);
+  return cht_do_hbcrypto_hash_discard(cd,ip,state_v);
+}
+
+int cht_do_hbcrypto_hash_discard(ClientData cd, Tcl_Interp *ip,
+                                void *state_v) {
+  cht_tabledataid_disposing(ip,state_v,&cht_hash_states);
+  free(state_v);
+  return TCL_OK;
+}
+
+int cht_do_hbcrypto_hash_clonestate(ClientData cd, Tcl_Interp *ip,
+                                   void *old_v, void **new_r) {
+  HashState *old= old_v;
+  int len= sizeof(*old) + old->alg->statesize - 1;
+  void *new_v= TALLOC(len);
+  memcpy(new_v, old, len);
+  ((HashState*)new_v)->ix= -1;
+  *new_r= new_v;
+  return TCL_OK;
+}
+
+
+static void destroy_idtabcb(Tcl_Interp *ip, void *state_v) {
+  free(state_v);
+}
+
+const IdDataSpec cht_hash_states= {
+  "hashstate", "hashstate-table", destroy_idtabcb
+};