commit 9988d6bbd98c538f3f5d9fcb70e7b6a0ab1e7298
author Paul Bakker <paul@brainspark.nl> Wed Jun 01 11:29:42 2016 +0100
committer Simon Butcher <simon.butcher@arm.com> Fri Jun 10 19:42:14 2016 +0100
tree 7297948ecf4da1475db53fcbba753db7bc2249a9
parent cf0a9f96c520f84a4299f68213dc0dbe06a273d0

Introduce mbedtls_nv_seed_poll() entropy polling function

include/mbedtls/entropy_poll.h

diff --git a/include/mbedtls/entropy_poll.h b/include/mbedtls/entropy_poll.h
index 3fcfef2..a2acc1a 100644
--- a/include/mbedtls/entropy_poll.h
+++ b/include/mbedtls/entropy_poll.h
@@ -3,7 +3,7 @@
  *
  * \brief Platform-specific and custom entropy polling functions
  *
- *  Copyright (C) 2006-2015, ARM Limited, All Rights Reserved
+ *  Copyright (C) 2006-2016, ARM Limited, All Rights Reserved
  *  SPDX-License-Identifier: Apache-2.0
  *
  *  Licensed under the Apache License, Version 2.0 (the "License"); you may
@@ -90,6 +90,16 @@
                            unsigned char *output, size_t len, size_t *olen );
 #endif
 
+#if defined(MBEDTLS_ENTROPY_NV_SEED)
+/**
+ * \brief           Entropy poll callback for a non-volatile seed file
+ *
+ * \note            This must accept NULL as its first argument.
+ */
+int mbedtls_nv_seed_poll( void *data,
+                          unsigned char *output, size_t len, size_t *olen );
+#endif
+
 #ifdef __cplusplus
 }
 #endif

library/entropy.c

diff --git a/library/entropy.c b/library/entropy.c
index 381f730..d42ca15 100644
--- a/library/entropy.c
+++ b/library/entropy.c
@@ -1,7 +1,7 @@
 /*
  *  Entropy accumulator implementation
  *
- *  Copyright (C) 2006-2015, ARM Limited, All Rights Reserved
+ *  Copyright (C) 2006-2016, ARM Limited, All Rights Reserved
  *  SPDX-License-Identifier: Apache-2.0
  *
  *  Licensed under the Apache License, Version 2.0 (the "License"); you may
@@ -99,6 +99,11 @@
                                 MBEDTLS_ENTROPY_MIN_HARDWARE,
                                 MBEDTLS_ENTROPY_SOURCE_STRONG );
 #endif
+#if defined(MBEDTLS_ENTROPY_NV_SEED)
+    mbedtls_entropy_add_source( ctx, mbedtls_nv_seed_poll, NULL,
+                                MBEDTLS_ENTROPY_BLOCK_SIZE,
+                                MBEDTLS_ENTROPY_SOURCE_STRONG );
+#endif
 #endif /* MBEDTLS_NO_DEFAULT_ENTROPY_SOURCES */
 }
 

library/entropy_poll.c

diff --git a/library/entropy_poll.c b/library/entropy_poll.c
index 79efb87..1ddbdc7 100644
--- a/library/entropy_poll.c
+++ b/library/entropy_poll.c
@@ -1,7 +1,7 @@
 /*
  *  Platform-specific and custom entropy polling functions
  *
- *  Copyright (C) 2006-2015, ARM Limited, All Rights Reserved
+ *  Copyright (C) 2006-2016, ARM Limited, All Rights Reserved
  *  SPDX-License-Identifier: Apache-2.0
  *
  *  Licensed under the Apache License, Version 2.0 (the "License"); you may
@@ -37,6 +37,9 @@
 #if defined(MBEDTLS_HAVEGE_C)
 #include "mbedtls/havege.h"
 #endif
+#if defined(MBEDTLS_ENTROPY_NV_SEED)
+#include "mbedtls/platform.h"
+#endif
 
 #if !defined(MBEDTLS_NO_PLATFORM_ENTROPY)
 
@@ -238,4 +241,27 @@
 }
 #endif /* MBEDTLS_HAVEGE_C */
 
+#if defined(MBEDTLS_ENTROPY_NV_SEED)
+int mbedtls_nv_seed_poll( void *data,
+                          unsigned char *output, size_t len, size_t *olen )
+{
+    unsigned char buf[MBEDTLS_ENTROPY_BLOCK_SIZE];
+    size_t use_len = MBEDTLS_ENTROPY_BLOCK_SIZE;
+    ((void) data);
+
+    memset( buf, 0, MBEDTLS_ENTROPY_BLOCK_SIZE );
+
+    if( mbedtls_nv_seed_read( buf, MBEDTLS_ENTROPY_BLOCK_SIZE ) < 0 )
+      return( MBEDTLS_ERR_ENTROPY_SOURCE_FAILED );
+
+    if( len < use_len )
+      use_len = len;
+
+    memcpy( output, buf, use_len );
+    *olen = use_len;
+
+    return( 0 );
+}
+#endif /* MBEDTLS_ENTROPY_NV_SEED */
+
 #endif /* MBEDTLS_ENTROPY_C */