build fixes

[disorder] / lib / authhash.c

diff --git a/lib/authhash.c b/lib/authhash.c
index a1012ba0e9ba570ee8c905dc4c2cf823d917b13a..24c40f08d22981700fd5ed1757e88087b36e2f6b 100644 (file)
--- a/lib/authhash.c
+++ b/lib/authhash.c
@@ -1,6 +1,6 @@
 /*
  * This file is part of DisOrder
- * Copyright (C) 2004, 2006 Richard Kettlewell
+ * Copyright (C) 2004, 2006, 2007 Richard Kettlewell
  *
  * 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
@@ -17,6 +17,7 @@
  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
  * USA
  */
+/** @file lib/authhash.c @brief The authorization hash */
 
 #include <config.h>
 #include "types.h"
@@ -29,36 +30,85 @@
 #include "log.h"
 #include "authhash.h"
 
-#ifndef AUTHHASH
-# define AUTHHASH GCRY_MD_SHA1
-#endif
+/** @brief Structure of algorithm lookup table */
+struct algorithm {
+  const char *name;
+  int id;
+};
+
+/** @brief Algorithm lookup table
+ *
+ * We don't use gcry_md_map_name() since that would import gcrypt's API into
+ * the disorder protocol.
+ */
+static const struct algorithm algorithms[] = {
+  { "SHA1", GCRY_MD_SHA1 },
+  { "sha1", GCRY_MD_SHA1 },
+  { "SHA256", GCRY_MD_SHA256 },
+  { "sha256", GCRY_MD_SHA256 },
+  { "SHA384", GCRY_MD_SHA384 },
+  { "sha384", GCRY_MD_SHA384 },
+  { "SHA512", GCRY_MD_SHA512 },
+  { "sha512", GCRY_MD_SHA512 },
+};
+
+/** @brief Number of supported algorithms */
+#define NALGORITHMS (sizeof algorithms / sizeof *algorithms)
 
+/** @brief Perform the authorization hash function
+ * @param challenge Pointer to challange
+ * @param nchallenge Size of challenge
+ * @param password Password
+ * @param algo Algorithm to use
+ *
+ * Computes H(challenge|password) and returns it as a newly allocated hex
+ * string, or returns NULL on error.
+ */
 const char *authhash(const void *challenge, size_t nchallenge,
-                    const char *password) {
+                    const char *password, const char *algo) {
   gcrypt_hash_handle h;
   const char *res;
+  size_t n;
+  int id;
 
   assert(challenge != 0);
   assert(password != 0);
+  assert(algo != 0);
+  for(n = 0; n < NALGORITHMS; ++n)
+    if(!strcmp(algo, algorithms[n].name))
+      break;
+  if(n >= NALGORITHMS)
+    return NULL;
+  id = algorithms[n].id;
 #if HAVE_GCRY_ERROR_T
   {
     gcry_error_t e;
     
-    if((e = gcry_md_open(&h, AUTHHASH, 0))) {
+    if((e = gcry_md_open(&h, id, 0))) {
       error(0, "gcry_md_open: %s", gcry_strerror(e));
       return 0;
     }
   }
 #else
-  h = gcry_md_open(AUTHHASH, 0);
+  h = gcry_md_open(id, 0);
 #endif
   gcry_md_write(h, password, strlen(password));
   gcry_md_write(h, challenge, nchallenge);
-  res = hex(gcry_md_read(h, AUTHHASH), gcry_md_get_algo_dlen(AUTHHASH));
+  res = hex(gcry_md_read(h, id), gcry_md_get_algo_dlen(id));
   gcry_md_close(h);
   return res;
 }
 
+/** @brief Return non-zero if @p algo is a valid algorithm */
+int valid_authhash(const char *algo) {
+  size_t n;
+
+  for(n = 0; n < NALGORITHMS; ++n)
+    if(!strcmp(algo, algorithms[n].name))
+      return 1;
+  return 0;
+}
+
 /*
 Local Variables:
 c-basic-offset:2