X-Git-Url: https://git.librecmc.org/?a=blobdiff_plain;f=src%2Futil%2Fcrypto_ecc.c;h=3cec128680f7e2bd38d9d4baf26557b80260a655;hb=72c8645af31896829b674b575c5375706f362a30;hp=d89989bd4c8287a4cfff2ec6aa59db7ff4d40e7b;hpb=dcb57a9e51e8fe7412948ec0c47d383ed390ed61;p=oweals%2Fgnunet.git

diff --git a/src/util/crypto_ecc.c b/src/util/crypto_ecc.c
index d89989bd4..3cec12868 100644
--- a/src/util/crypto_ecc.c
+++ b/src/util/crypto_ecc.c
@@ -1,6 +1,6 @@
 /*
      This file is part of GNUnet.
-     (C) 2001, 2002, 2003, 2004, 2005, 2006, 2009, 2012 Christian Grothoff (and other contributing authors)
+     (C) 2012, 2013 Christian Grothoff (and other contributing authors)
 
      GNUnet is free software; you can redistribute it and/or modify
      it under the terms of the GNU General Public License as published
@@ -30,7 +30,7 @@
 
 #define EXTRA_CHECKS ALLOW_EXTRA_CHECKS 
 
-#define CURVE "NIST P-521"
+#define CURVE "NIST P-256"
 
 #define LOG(kind,...) GNUNET_log_from (kind, "util", __VA_ARGS__)
 
@@ -216,8 +216,8 @@ GNUNET_CRYPTO_ecc_public_key_from_string (const char *enc,
     return GNUNET_SYSERR;
 
   if (GNUNET_OK != GNUNET_STRINGS_string_to_data (enc, enclen,
-						 (unsigned char*) pub,
-						 sizeof (struct GNUNET_CRYPTO_EccPublicKeyBinaryEncoded)))
+						  pub,
+						  sizeof (struct GNUNET_CRYPTO_EccPublicKeyBinaryEncoded)))
     return GNUNET_SYSERR;
   if ( (ntohs (pub->size) != sizeof (struct GNUNET_CRYPTO_EccPublicKeyBinaryEncoded)) ||
        (ntohs (pub->len) > GNUNET_CRYPTO_ECC_SIGNATURE_DATA_ENCODING_LENGTH) )
@@ -263,16 +263,13 @@ decode_public_key (const struct GNUNET_CRYPTO_EccPublicKeyBinaryEncoded *publicK
     LOG_GCRY (GNUNET_ERROR_TYPE_ERROR, "gcry_sexp_build", rc);  /* erroff gives more info */
     return NULL;
   }
-  // FIXME: is this key expected to pass pk_testkey?
-#if 0
-#if EXTRA_CHECKS 
+#if EXTRA_CHECKS
   if (0 != (rc = gcry_pk_testkey (result)))
   {
     LOG_GCRY (GNUNET_ERROR_TYPE_ERROR, "gcry_pk_testkey", rc);
     gcry_sexp_release (result);
     return NULL;
   }
-#endif
 #endif
   return result;
 }
@@ -407,72 +404,6 @@ GNUNET_CRYPTO_ecc_key_create ()
 }
 
 
-/**
- * Try to read the private key from the given file.
- *
- * @param filename file to read the key from
- * @return NULL on error
- */
-static struct GNUNET_CRYPTO_EccPrivateKey *
-try_read_key (const char *filename)
-{
-  struct GNUNET_CRYPTO_EccPrivateKey *ret;
-  struct GNUNET_DISK_FileHandle *fd;
-  OFF_T fs;
-
-  if (GNUNET_YES != GNUNET_DISK_file_test (filename))
-    return NULL;
-
-  /* key file exists already, read it! */
-  if (NULL == (fd = GNUNET_DISK_file_open (filename, GNUNET_DISK_OPEN_READ,
-					   GNUNET_DISK_PERM_NONE)))
-  {
-    LOG_STRERROR_FILE (GNUNET_ERROR_TYPE_ERROR, "open", filename);
-    return NULL;
-  }
-  if (GNUNET_OK != (GNUNET_DISK_file_handle_size (fd, &fs)))
-  {
-    LOG_STRERROR_FILE (GNUNET_ERROR_TYPE_ERROR, "stat", filename);
-    (void) GNUNET_DISK_file_close (fd);
-    return NULL;
-  }
-  if (0 == fs)
-  {
-    GNUNET_break (GNUNET_OK == GNUNET_DISK_file_close (fd));
-    return NULL;
-  }
-  if (fs > UINT16_MAX)
-  {
-    LOG (GNUNET_ERROR_TYPE_ERROR,
-         _("File `%s' does not contain a valid private key (too long, %llu bytes).  Deleting it.\n"),	
-         filename,
-	 (unsigned long long) fs);
-    GNUNET_break (GNUNET_OK == GNUNET_DISK_file_close (fd));
-    if (0 != UNLINK (filename))    
-      LOG_STRERROR_FILE (GNUNET_ERROR_TYPE_WARNING, "unlink", filename);
-    return NULL;
-  }
-  {
-    char enc[fs];
-
-    GNUNET_break (fs == GNUNET_DISK_file_read (fd, enc, fs));
-    if (NULL == (ret = GNUNET_CRYPTO_ecc_decode_key ((char *) enc, fs, GNUNET_YES)))
-    {
-      LOG (GNUNET_ERROR_TYPE_ERROR,
-	   _("File `%s' does not contain a valid private key (failed decode, %llu bytes).  Deleting it.\n"),
-	   filename,
-	   (unsigned long long) fs);
-      GNUNET_break (GNUNET_OK == GNUNET_DISK_file_close (fd));
-      if (0 != UNLINK (filename))    
-	LOG_STRERROR_FILE (GNUNET_ERROR_TYPE_WARNING, "unlink", filename);
-      return NULL;
-    }
-  }
-  GNUNET_break (GNUNET_OK == GNUNET_DISK_file_close (fd));
-  return ret;  
-}
-
-
 /**
  * Wait for a short time (we're trying to lock a file or want
  * to give another process a shot at finishing a disk write, etc.).
@@ -677,217 +608,24 @@ GNUNET_CRYPTO_ecc_key_create_from_file (const char *filename)
 
 
 /**
- * Handle to cancel private key generation and state for the
- * key generation operation.
- */
-struct GNUNET_CRYPTO_EccKeyGenerationContext
-{
-  
-  /**
-   * Continuation to call upon completion.
-   */
-  GNUNET_CRYPTO_EccKeyCallback cont;
-
-  /**
-   * Closure for 'cont'.
-   */
-  void *cont_cls;
-
-  /**
-   * Name of the file.
-   */
-  char *filename;
-
-  /**
-   * Handle to the helper process which does the key generation.
-   */ 
-  struct GNUNET_OS_Process *gnunet_ecc;
-  
-  /**
-   * Handle to 'stdout' of gnunet-ecc.  We 'read' on stdout to detect
-   * process termination (instead of messing with SIGCHLD).
-   */
-  struct GNUNET_DISK_PipeHandle *gnunet_ecc_out;
-
-  /**
-   * Location where we store the private key if it already existed.
-   * (if this is used, 'filename', 'gnunet_ecc' and 'gnunet_ecc_out' will
-   * not be used).
-   */
-  struct GNUNET_CRYPTO_EccPrivateKey *pk;
-  
-  /**
-   * Task reading from 'gnunet_ecc_out' to wait for process termination.
-   */
-  GNUNET_SCHEDULER_TaskIdentifier read_task;
-  
-};
-
-
-/**
- * Abort ECC key generation.
+ * Create a new private key by reading our peer's key from
+ * the file specified in the configuration.
  *
- * @param gc key generation context to abort
- */
-void
-GNUNET_CRYPTO_ecc_key_create_stop (struct GNUNET_CRYPTO_EccKeyGenerationContext *gc)
-{
-  if (GNUNET_SCHEDULER_NO_TASK != gc->read_task)
-  {
-    GNUNET_SCHEDULER_cancel (gc->read_task);
-    gc->read_task = GNUNET_SCHEDULER_NO_TASK;
-  }
-  if (NULL != gc->gnunet_ecc)
-  {
-    (void) GNUNET_OS_process_kill (gc->gnunet_ecc, SIGKILL);
-    GNUNET_break (GNUNET_OK ==
-		  GNUNET_OS_process_wait (gc->gnunet_ecc));
-    GNUNET_OS_process_destroy (gc->gnunet_ecc);
-    GNUNET_DISK_pipe_close (gc->gnunet_ecc_out);
-  }
-
-  if (NULL != gc->filename)
-  {
-    if (0 != UNLINK (gc->filename))
-      GNUNET_log_strerror_file (GNUNET_ERROR_TYPE_WARNING, "unlink", gc->filename);
-    GNUNET_free (gc->filename);
-  }
-  if (NULL != gc->pk)
-    GNUNET_CRYPTO_ecc_key_free (gc->pk);
-  GNUNET_free (gc);
-}
-
-
-/**
- * Task called upon shutdown or process termination of 'gnunet-ecc' during
- * ECC key generation.  Check where we are and perform the appropriate
- * action.
- *
- * @param cls the 'struct GNUNET_CRYPTO_EccKeyGenerationContext'
- * @param tc scheduler context
- */
-static void
-check_key_generation_completion (void *cls,
-				 const struct GNUNET_SCHEDULER_TaskContext *tc)
-{
-  struct GNUNET_CRYPTO_EccKeyGenerationContext *gc = cls;
-  struct GNUNET_CRYPTO_EccPrivateKey *pk;
-
-  gc->read_task = GNUNET_SCHEDULER_NO_TASK;
-  if (0 != (tc->reason & GNUNET_SCHEDULER_REASON_SHUTDOWN))
-  {
-    gc->cont (gc->cont_cls, NULL, _("interrupted by shutdown"));
-    GNUNET_CRYPTO_ecc_key_create_stop (gc);
-    return;
-  }
-  GNUNET_assert (GNUNET_OK == 
-		 GNUNET_OS_process_wait (gc->gnunet_ecc));
-  GNUNET_OS_process_destroy (gc->gnunet_ecc);
-  gc->gnunet_ecc = NULL;
-  if (NULL == (pk = try_read_key (gc->filename)))
-  {
-    GNUNET_break (0);
-    gc->cont (gc->cont_cls, NULL, _("gnunet-ecc failed"));
-    GNUNET_CRYPTO_ecc_key_create_stop (gc);
-    return;
-  }
-  gc->cont (gc->cont_cls, pk, NULL);
-  GNUNET_DISK_pipe_close (gc->gnunet_ecc_out);
-  GNUNET_free (gc->filename);
-  GNUNET_free (gc);
-}
-
-
-/**
- * Return the private ECC key which already existed on disk
- * (asynchronously) to the caller.
- *
- * @param cls the 'struct GNUNET_CRYPTO_EccKeyGenerationContext'
- * @param tc scheduler context (unused)
- */
-static void
-async_return_key (void *cls,
-		  const struct GNUNET_SCHEDULER_TaskContext *tc)
-{
-  struct GNUNET_CRYPTO_EccKeyGenerationContext *gc = cls;
-
-  gc->cont (gc->cont_cls,
-	    gc->pk,
-	    NULL);
-  GNUNET_free (gc);
-}
-
-
-/**
- * Create a new private key by reading it from a file.  If the files
- * does not exist, create a new key and write it to the file.  If the
- * contents of the file are invalid the old file is deleted and a
- * fresh key is created.
- *
- * @param filename name of file to use for storage
- * @param cont function to call when done (or on errors)
- * @param cont_cls closure for 'cont'
- * @return handle to abort operation, NULL on fatal errors (cont will not be called if NULL is returned)
+ * @return new private key, NULL on error (for example,
+ *   permission denied)
  */
-struct GNUNET_CRYPTO_EccKeyGenerationContext *
-GNUNET_CRYPTO_ecc_key_create_start (const char *filename,
-				    GNUNET_CRYPTO_EccKeyCallback cont,
-				    void *cont_cls)
+struct GNUNET_CRYPTO_EccPrivateKey *
+GNUNET_CRYPTO_ecc_key_create_from_configuration (const struct GNUNET_CONFIGURATION_Handle *cfg)
 {
-  struct GNUNET_CRYPTO_EccKeyGenerationContext *gc;
   struct GNUNET_CRYPTO_EccPrivateKey *pk;
+  char *fn;
 
-  if (NULL != (pk = try_read_key (filename)))
-  {
-    /* quick happy ending: key already exists! */
-    gc = GNUNET_malloc (sizeof (struct GNUNET_CRYPTO_EccKeyGenerationContext));
-    gc->pk = pk;
-    gc->cont = cont;
-    gc->cont_cls = cont_cls;
-    gc->read_task = GNUNET_SCHEDULER_add_now (&async_return_key,
-					      gc);
-    return gc;
-  }
-  gc = GNUNET_malloc (sizeof (struct GNUNET_CRYPTO_EccKeyGenerationContext));
-  gc->filename = GNUNET_strdup (filename);
-  gc->cont = cont;
-  gc->cont_cls = cont_cls;
-  gc->gnunet_ecc_out = GNUNET_DISK_pipe (GNUNET_NO,
-					 GNUNET_NO,
-					 GNUNET_NO,
-					 GNUNET_YES);
-  if (NULL == gc->gnunet_ecc_out)
-  {
-    GNUNET_log_strerror (GNUNET_ERROR_TYPE_WARNING, "pipe");
-    GNUNET_free (gc->filename);
-    GNUNET_free (gc);
-    return NULL;
-  }
-  gc->gnunet_ecc = GNUNET_OS_start_process (GNUNET_NO,
-					    GNUNET_OS_INHERIT_STD_ERR,
-					    NULL, 
-					    gc->gnunet_ecc_out,
-					    "gnunet-ecc",
-					    "gnunet-ecc",					    
-					    gc->filename,
-					    NULL);
-  if (NULL == gc->gnunet_ecc)
-  {
-    GNUNET_log_strerror (GNUNET_ERROR_TYPE_WARNING, "fork");
-    GNUNET_DISK_pipe_close (gc->gnunet_ecc_out);
-    GNUNET_free (gc->filename);
-    GNUNET_free (gc);
+  if (GNUNET_OK != 
+      GNUNET_CONFIGURATION_get_value_filename (cfg, "PEER", "PRIVATE_KEY", &fn))
     return NULL;
-  }
-  GNUNET_assert (GNUNET_OK ==
-		 GNUNET_DISK_pipe_close_end (gc->gnunet_ecc_out,
-					     GNUNET_DISK_PIPE_END_WRITE));
-  gc->read_task = GNUNET_SCHEDULER_add_read_file (GNUNET_TIME_UNIT_FOREVER_REL,
-						  GNUNET_DISK_pipe_handle (gc->gnunet_ecc_out,
-									   GNUNET_DISK_PIPE_END_READ),
-						  &check_key_generation_completion,
-						  gc);
-  return gc;
+  pk = GNUNET_CRYPTO_ecc_key_create_from_file (fn);
+  GNUNET_free (fn);
+  return pk;
 }
 
 
@@ -904,19 +642,41 @@ GNUNET_CRYPTO_ecc_setup_key (const char *cfg_name)
 {
   struct GNUNET_CONFIGURATION_Handle *cfg;
   struct GNUNET_CRYPTO_EccPrivateKey *pk;
-  char *fn;
 
   cfg = GNUNET_CONFIGURATION_create ();
   (void) GNUNET_CONFIGURATION_load (cfg, cfg_name);
-  if (GNUNET_OK == 
-      GNUNET_CONFIGURATION_get_value_filename (cfg, "PEER", "PRIVATE_KEY", &fn))
+  pk = GNUNET_CRYPTO_ecc_key_create_from_configuration (cfg);
+  if (NULL != pk)
+    GNUNET_CRYPTO_ecc_key_free (pk);
+  GNUNET_CONFIGURATION_destroy (cfg);
+}
+
+
+/**
+ * Retrieve the identity of the host's peer.
+ *
+ * @param cfg configuration to use
+ * @param dst pointer to where to write the peer identity
+ * @return GNUNET_OK on success, GNUNET_SYSERR if the identity
+ *         could not be retrieved
+ */
+int
+GNUNET_CRYPTO_get_host_identity (const struct GNUNET_CONFIGURATION_Handle *cfg,
+                                 struct GNUNET_PeerIdentity *dst)
+{
+  struct GNUNET_CRYPTO_EccPrivateKey *my_private_key;
+  struct GNUNET_CRYPTO_EccPublicKeyBinaryEncoded my_public_key;
+
+  if (NULL == (my_private_key = GNUNET_CRYPTO_ecc_key_create_from_configuration (cfg)))
   {
-    pk = GNUNET_CRYPTO_ecc_key_create_from_file (fn);
-    if (NULL != pk)
-      GNUNET_CRYPTO_ecc_key_free (pk);
-    GNUNET_free (fn);
+    GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
+                _("Could not load peer's private key\n"));
+    return GNUNET_SYSERR;
   }
-  GNUNET_CONFIGURATION_destroy (cfg);
+  GNUNET_CRYPTO_ecc_key_get_public (my_private_key, &my_public_key);
+  GNUNET_CRYPTO_ecc_key_free (my_private_key);
+  GNUNET_CRYPTO_hash (&my_public_key, sizeof (my_public_key), &dst->hashPubKey);
+  return GNUNET_OK;
 }
 
 
@@ -977,6 +737,8 @@ GNUNET_CRYPTO_ecc_sign (const struct GNUNET_CRYPTO_EccPrivateKey *key,
     LOG (GNUNET_ERROR_TYPE_WARNING,
          _("ECC signing failed at %s:%d: %s\n"), __FILE__,
          __LINE__, gcry_strerror (rc));
+    gcry_sexp_release (data);
+    return GNUNET_SYSERR;
   }
   gcry_sexp_release (data);
   ssize = gcry_sexp_sprint (result, 
@@ -1064,74 +826,85 @@ GNUNET_CRYPTO_ecc_ecdh (const struct GNUNET_CRYPTO_EccPrivateKey *key,
                         const struct GNUNET_CRYPTO_EccPublicKeyBinaryEncoded *pub,
                         struct GNUNET_HashCode *key_material)
 { 
-  size_t size;
   size_t slen;
+  size_t erroff;
   int rc;
-  gcry_sexp_t data;  
-  unsigned char sdata_buf[2048]; /* big enough to print 'sdata' and 'r_sig' */
+  unsigned char sdata_buf[2048]; /* big enough to print dh-shared-secret as S-expression */
+  gcry_mpi_point_t result;
+  gcry_mpi_point_t q;
+  gcry_mpi_t d;
+  gcry_ctx_t ctx;
+  gcry_sexp_t psexp;
+  gcry_mpi_t result_x;
+  gcry_mpi_t result_y;
 
-  /* first, extract the q value from the public key */
+  /* first, extract the q = dP value from the public key */
+  if (! (psexp = decode_public_key (pub)))
+    return GNUNET_SYSERR;
+  if (0 != (rc = gcry_mpi_ec_new (&ctx, psexp, NULL)))
   {
-    gcry_sexp_t psexp;
-    gcry_mpi_t sdata;
-    
-    if (! (psexp = decode_public_key (pub)))
-      return GNUNET_SYSERR;
-    rc = key_from_sexp (&sdata, psexp, "public-key", "q");
-    if (rc)
-      rc = key_from_sexp (&sdata, psexp, "ecc", "q");
-    GNUNET_assert (0 == rc);  
-    gcry_sexp_release (psexp);
-    size = sizeof (sdata_buf);
-    GNUNET_assert (0 ==
-		   gcry_mpi_print (GCRYMPI_FMT_USG, sdata_buf, size, &size,
-				   sdata));
-    gcry_mpi_release (sdata);
+    LOG_GCRY (GNUNET_ERROR_TYPE_ERROR, "gcry_mpi_ec_new", rc);  /* erroff gives more info */
+    return GNUNET_SYSERR;
   }
-  /* convert q value into an S-expression -- whatever format libgcrypt wants,
-     re-using format from sign operation for now... */
+  gcry_sexp_release (psexp);
+  q = gcry_mpi_ec_get_point ("q", ctx, 0);
+  gcry_ctx_release (ctx);
+
+  /* second, extract the d value from our private key */
+  rc = key_from_sexp (&d, key->sexp, "private-key", "d");
+  if (rc)
+    rc = key_from_sexp (&d, key->sexp, "ecc", "d");
+  if (0 != rc)
   {
-    char *sexp_string;
-
-#define FORMATPREFIX "(4:data(5:flags3:raw)(5:value%u:"
-#define FORMATPOSTFIX "))"
-    sexp_string = GNUNET_malloc (strlen (FORMATPREFIX) + size + 12 +
-				  strlen (FORMATPOSTFIX) + 1);
-    GNUNET_snprintf (sexp_string,
-		     strlen (FORMATPREFIX) + 12,
-		     FORMATPREFIX,
-		     size);
-    slen = strlen (sexp_string);
-    memcpy (&sexp_string[slen],
-	    sdata_buf, 
-	    size);
-    memcpy (&sexp_string[slen + size],
-	    FORMATPOSTFIX,
-	    strlen (FORMATPOSTFIX) + 1);  
-    GNUNET_assert (0 == gcry_sexp_new (&data, 
-				       sexp_string, 
-				       slen + size + strlen (FORMATPOSTFIX), 
-				       0));
-    GNUNET_free (sexp_string);
+    GNUNET_break (0);
+    gcry_mpi_point_release (q);
+    return GNUNET_SYSERR;
   }
-  /* then call the 'multiply' function, hoping it simply multiplies the points;
-     here we need essentially a WRAPPER around _gcry_mpi_ex_mul_point! - FIXME-WK!*/
-#if WK
+
+  /* create a new context for definitively the correct curve;
+     theoretically the 'public_key' might not use the right curve */
+  if (0 != (rc = gcry_mpi_ec_new (&ctx, NULL, "NIST P-256")))
   {
-    gcry_sexp_t result;
-    
-    rc = gcry_ecc_mul_point (&result, data /* scalar */, key->sexp /* point and ctx */);
-    GNUNET_assert (0 == rc);
-    slen = gcry_sexp_sprint (result, GCRYSEXP_FMT_DEFAULT, sdata_buf, sizeof (sdata_buf));
-    GNUNET_assert (0 != slen);
+    LOG_GCRY (GNUNET_ERROR_TYPE_ERROR, "gcry_mpi_ec_new", rc);  /* erroff gives more info */
+    gcry_mpi_release (d);
+    gcry_mpi_point_release (q);
+    return GNUNET_SYSERR;
   }
-#else
-  /* use broken version, insecure! */
-  GNUNET_log (GNUNET_ERROR_TYPE_WARNING, _("To be implemented: not secure at the moment, please read README\n"));
-  slen = sprintf ((char*) sdata_buf, "FIXME-this is not key material");
-#endif
-  gcry_sexp_release (data);
 
+  /* then call the 'multiply' function, to compute the product */
+  GNUNET_assert (NULL != ctx);
+  result = gcry_mpi_point_new (0);
+  gcry_mpi_ec_mul (result, d, q, ctx);
+  gcry_mpi_point_release (q);
+  gcry_mpi_release (d);
+
+  /* finally, convert point to string for hashing */
+  result_x = gcry_mpi_new (256);
+  result_y = gcry_mpi_new (256);
+  if (gcry_mpi_ec_get_affine (result_x, result_y, result, ctx))
+  {
+    LOG_GCRY (GNUNET_ERROR_TYPE_ERROR, "get_affine failed", 0);
+    gcry_mpi_point_release (result);
+    gcry_ctx_release (ctx);
+    return GNUNET_SYSERR;
+  }
+  gcry_mpi_point_release (result);
+  gcry_ctx_release (ctx);
+  if (0 != (rc = gcry_sexp_build (&psexp, &erroff, 
+				  "(dh-shared-secret (x %m)(y %m))",
+				  result_x,
+				  result_y)))
+  {
+    LOG_GCRY (GNUNET_ERROR_TYPE_ERROR, "gcry_sexp_build", rc);  /* erroff gives more info */
+    gcry_mpi_release (result_x);
+    gcry_mpi_release (result_y);
+    return GNUNET_SYSERR;
+  }
+  gcry_mpi_release (result_x);
+  gcry_mpi_release (result_y);
+  slen = gcry_sexp_sprint (psexp, GCRYSEXP_FMT_DEFAULT, sdata_buf, sizeof (sdata_buf));
+  GNUNET_assert (0 != slen);
+  gcry_sexp_release (psexp);
   /* finally, get a string of the resulting S-expression and hash it to generate the key material */
   GNUNET_CRYPTO_hash (sdata_buf, slen, key_material);
   return GNUNET_OK;