- implemented, untested
authorMartin Willi <martin@strongswan.org>
Tue, 22 Nov 2005 12:30:31 +0000 (12:30 -0000)
committerMartin Willi <martin@strongswan.org>
Tue, 22 Nov 2005 12:30:31 +0000 (12:30 -0000)
Source/charon/transforms/prf_plus.c [new file with mode: 0644]
Source/charon/transforms/prf_plus.h [new file with mode: 0644]

diff --git a/Source/charon/transforms/prf_plus.c b/Source/charon/transforms/prf_plus.c
new file mode 100644 (file)
index 0000000..2469fde
--- /dev/null
@@ -0,0 +1,175 @@
+/**
+ * @file prf_plus.c
+ * 
+ * @brief Implements the prf+ function described in IKEv2 draft.
+ * 
+ */
+
+/*
+ * Copyright (C) 2005 Jan Hutter, Martin Willi
+ * Hochschule fuer Technik Rapperswil
+ *
+ * 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.  See <http://www.fsf.org/copyleft/gpl.txt>.
+ *
+ * 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.
+ */
+
+
+#include "prf_plus.h"
+
+#include "../utils/allocator.h"
+#include "../definitions.h"
+
+/**
+ * Private data of an prf_plus_t object.
+ * 
+ */
+typedef struct private_prf_plus_s private_prf_plus_t;
+
+struct private_prf_plus_s {
+       /**
+        * public prf_plus_t interface
+        */
+       prf_plus_t public;
+       
+       /**
+        * prf to use
+        */
+       prf_t *prf;
+       
+       /**
+        * initial seed
+        */
+       chunk_t seed;
+       
+       /**
+        * buffer to store current prf result
+        */
+       chunk_t buffer;
+               
+       /**
+        * already given out bytes in current buffer
+        */
+       size_t given_out;
+       
+       /**
+        * octet which will be appended to the seed
+        */
+       u_int8_t appending_octet;
+};
+
+
+/**
+ * implementation of prf_plus_t.get_bytes
+ */
+static status_t get_bytes(private_prf_plus_t *this, size_t length, u_int8_t *buffer)
+{      
+       chunk_t appending_chunk;
+       size_t bytes_in_round;
+       
+       appending_chunk.ptr = &(this->appending_octet);
+       appending_chunk.len = 1;
+       
+       while (length)
+       {       /* still more to do... */
+               if (this->buffer.len == this->given_out)
+               {       /* no bytes left in buffer, get next*/  
+                       this->prf->get_bytes(this->prf, this->buffer, NULL);
+                       this->prf->get_bytes(this->prf, this->seed, NULL);
+                       this->prf->get_bytes(this->prf, appending_chunk, this->buffer.ptr);
+                       this->given_out = 0;
+                       this->appending_octet++;
+               }
+               /* how many bytes can we write in this round ? */
+               bytes_in_round = min(length, this->buffer.len - this->given_out);
+               /* copy bytes from buffer with offset */
+               memcpy(buffer, this->buffer.ptr + this->given_out, bytes_in_round);
+               
+               length -= bytes_in_round;
+               this->given_out += bytes_in_round;
+       }
+       return SUCCESS;
+}
+
+/**
+ * implementation of prf_plus_t.allocate_bytes
+ */    
+static status_t allocate_bytes(private_prf_plus_t *this, size_t length, chunk_t *chunk)
+{
+       chunk->ptr = allocator_alloc(length);
+       chunk->len = length;
+       if (chunk->ptr == NULL)
+       {
+               return OUT_OF_RES;      
+       }
+       return this->public.get_bytes(&(this->public), length, chunk->ptr);
+}
+
+/**
+ * implementation of prf_plus_t.destroy
+ */
+static status_t destroy(private_prf_plus_t *this)
+{
+       allocator_free(this->buffer.ptr);
+       allocator_free(this->seed.ptr);
+       allocator_free(this);
+       return SUCCESS;
+}
+
+/*
+ * Description in header
+ */
+prf_plus_t *prf_plus_create(prf_t *prf, chunk_t seed)
+{
+       private_prf_plus_t *this;
+       chunk_t appending_chunk;
+       
+       this = allocator_alloc_thing(private_prf_plus_t);
+       if (this == NULL)
+       {
+               return NULL;    
+       }
+       /* set public methods */
+       this->public.get_bytes = (size_t (*)(prf_plus_t *,size_t,u_int8_t*))get_bytes;
+       this->public.allocate_bytes = (size_t (*)(prf_plus_t *,size_t,chunk_t*))allocate_bytes;
+       this->public.destroy = (status_t (*)(prf_plus_t *))destroy;
+       
+       /* take over prf */
+       this->prf = prf;
+       
+       /* allocate buffer for prf output */
+       this->buffer.len = prf->get_block_size(prf);
+       this->buffer.ptr = allocator_alloc(this->buffer.len);
+       if (this->buffer.ptr == NULL)
+       {
+               allocator_free(this);
+               return NULL;
+       }
+       this->appending_octet = 0x01;
+       
+       /* clone seed */
+       this->seed.ptr = allocator_clone_bytes(seed.ptr, seed.len);
+       this->seed.len = seed.len;
+       if (this->seed.ptr == NULL)
+       {
+               allocator_free(this->buffer.ptr);
+               allocator_free(this);
+               return NULL;    
+       }
+       
+       /* do the first run */
+       appending_chunk.ptr = &(this->appending_octet);
+       appending_chunk.len = 1;
+       this->prf->get_bytes(this->prf, this->seed, NULL);
+       this->prf->get_bytes(this->prf, appending_chunk, this->buffer.ptr);
+       this->given_out = 0;
+       this->appending_octet++;
+       
+       return &(this->public);
+}
diff --git a/Source/charon/transforms/prf_plus.h b/Source/charon/transforms/prf_plus.h
new file mode 100644 (file)
index 0000000..6d1fb96
--- /dev/null
@@ -0,0 +1,84 @@
+/**
+ * @file prf_plus.h
+ * 
+ * @brief Implements the prf+ function described in IKEv2 draft.
+ * 
+ */
+
+/*
+ * Copyright (C) 2005 Jan Hutter, Martin Willi
+ * Hochschule fuer Technik Rapperswil
+ *
+ * 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.  See <http://www.fsf.org/copyleft/gpl.txt>.
+ *
+ * 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.
+ */
+
+#ifndef PRF_PLUS_H_
+#define PRF_PLUS_H_
+
+
+#include "prfs/prf.h"
+
+
+/**
+ * Object representing a prf_plus
+ */
+typedef struct prf_plus_s prf_plus_t;
+
+struct prf_plus_s {
+       /**
+        * @brief Get pseudo random bytes.
+        * 
+        * @param this                  calling prf_plus
+        * @param length                number of bytes to get
+        * @param [out]buffer   pointer where the generated bytes will be written
+        * @return                              
+        *                                              - SUCCESS in any case
+        */
+       status_t (*get_bytes) (prf_plus_t *this, size_t length, u_int8_t *buffer);
+       
+       /**
+        * @brief Allocate pseudo random bytes.
+        * 
+        * @param this                  calling prf_plus
+        * @param length                number of bytes to get
+        * @param [out]chunk    chunk which will hold generated bytes
+        * @return                              
+        *                                              - SUCCESS in any case
+        *                                              - OUT_OF_RES if space could not be allocated
+        */
+       status_t (*allocate_bytes) (prf_plus_t *this, size_t length, chunk_t *chunk);
+       
+       /**
+        * @brief Destroys a prf_plus object.
+        *
+        * @param this                  prf_plus_t object to destroy
+        * @return              
+        *                                              - SUCCESS in any case
+        */
+       status_t (*destroy) (prf_plus_t *this);
+};
+
+/**
+ * Creates a new prf_plus_t object
+ * 
+ * Seed will be cloned. prf will
+ * not be cloned, must be destroyed outside after
+ * prf_plus usage.
+ * 
+ * @param prf                          prf object to use
+ * @param seed                         input seed for prf
+ * @return
+ *                                                     - prf_plus_t if successfully
+ *                                                     - NULL if out of ressources or hash not supported
+ */
+prf_plus_t *prf_plus_create(prf_t *prf, chunk_t seed);
+
+#endif /*PRF_PLUS_H_*/