- Added CTR_DRBG based on AES-256-CTR (NIST SP 800-90) random generator
diff --git a/include/polarssl/config.h b/include/polarssl/config.h
index 48b2661..27f520b 100644
--- a/include/polarssl/config.h
+++ b/include/polarssl/config.h
@@ -307,6 +307,18 @@
#define POLARSSL_CIPHER_C
/**
+ * \def POLARSSL_CTR_DRBG_C
+ *
+ * Enable the CTR_DRBG AES-256-based random generator
+ *
+ * Module: library/ctr_drbg.c
+ * Caller:
+ *
+ * This module provides the CTR_DRBG AES-256 random number generator.
+ */
+#define POLARSSL_CTR_DRBG_C
+
+/**
* \def POLARSSL_DEBUG_C
*
* Enable the debug functions.
diff --git a/include/polarssl/ctr_drbg.h b/include/polarssl/ctr_drbg.h
new file mode 100644
index 0000000..da70611
--- /dev/null
+++ b/include/polarssl/ctr_drbg.h
@@ -0,0 +1,199 @@
+/**
+ * \file ctr_drbg.h
+ *
+ * \brief CTR_DRBG based on AES-256 (NIST SP 800-90)
+ *
+ * Copyright (C) 2006-2010, Brainspark B.V.
+ *
+ * This file is part of PolarSSL (http://www.polarssl.org)
+ * Lead Maintainer: Paul Bakker <polarssl_maintainer at polarssl.org>
+ *
+ * All rights reserved.
+ *
+ * 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 program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+#ifndef POLARSSL_CTR_DRBG_H
+#define POLARSSL_CTR_DRBG_H
+
+#include <string.h>
+
+#include "aes.h"
+
+#define POLARSSL_ERR_CTR_DRBG_ENTROPY_SOURCE_FAILED -0x0034 /**< The entropy source failed. */
+#define POLARSSL_ERR_CTR_DRBG_REQUEST_TOO_BIG -0x0036 /**< Too many random requested in single call. */
+#define POLARSSL_ERR_CTR_DRBG_INPUT_TOO_BIG -0x0038 /**< Input too large (Entropy + additional). */
+
+#define CTR_DRBG_SEEDLEN 48 /**< The seed length (counter + AES key) */
+#define CTR_DRBG_ENTROPY_LEN 32 /**< Amount of entropy used per seed by default */
+#define CTR_DRBG_RESEED_INTERVAL 10000 /**< Interval before reseed is performed by default */
+#define CTR_DRBG_MAX_INPUT 256 /**< Maximum number of additional input bytes */
+#define CTR_DRBG_MAX_REQUEST 500 /**< Maximum number of requested bytes per call */
+#define CTR_DRBG_MAX_SEED_INPUT 384 /**< Maximum size of (re)seed buffer */
+
+#define CTR_DRBG_PR_OFF 0 /**< No prediction resistance */
+#define CTR_DRBG_PR_ON 1 /**< Prediction resistance enabled */
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/**
+ * \brief CTR_DRBG context structure
+ */
+typedef struct
+{
+ unsigned char counter[16]; /*!< counter (V) */
+ int reseed_counter; /*!< reseed counter */
+ int prediction_resistance; /*!< enable prediction resistance (Automatic
+ reseed before every random generation) */
+ size_t entropy_len; /*!< amount of entropy grabbed on each (re)seed */
+ int reseed_interval; /*!< reseed interval */
+
+ aes_context aes_ctx; /*!< AES context */
+
+ /*
+ * Callbacks (Entropy)
+ */
+ int (*f_entropy)(void *, unsigned char *, size_t);
+
+ void *p_entropy; /*!< context for the entropy function */
+}
+ctr_drbg_context;
+
+/**
+ * \brief CTR_DRBG initialization
+ *
+ * Note: Personalization data can be provided in addition to the more generic
+ * entropy source to make this instantiation as unique as possible.
+ *
+ * \param ctx CTR_DRBG context to be initialized
+ * \param f_entropy Entropy callback (p_entropy, buffer to fill, buffer
+ * length)
+ * \param p_entropy Entropy context
+ * \param custom Personalization data (Device specific identifiers)
+ * \param len Length of personalization data
+ *
+ * \return 0 if successful, or
+ * POLARSSL_ERR_CTR_DRBG_ENTROPY_SOURCE_FAILED
+ */
+int ctr_drbg_init( ctr_drbg_context *ctx,
+ int (*f_entropy)(void *, unsigned char *, size_t),
+ void *p_entropy,
+ unsigned char *custom,
+ size_t len );
+
+/**
+ * \brief Enable / disable prediction resistance (Default: Off)
+ *
+ * Note: If enabled, entropy is used for ctx->entropy_len before each call!
+ * Only use this if you have ample supply of good entropy!
+ *
+ * \param ctx CTR_DRBG context
+ * \param resistance CTR_DRBG_PR_ON or CTR_DRBG_PR_OFF
+ */
+void ctr_drbg_set_prediction_resistance( ctr_drbg_context *ctx,
+ int resistance );
+
+/**
+ * \brief Set the amount of entropy grabbed on each (re)seed
+ * (Default: CTR_DRBG_ENTROPY_LEN)
+ *
+ * \param ctx CTR_DRBG context
+ * \param len Amount of entropy to grab
+ */
+void ctr_drbg_set_entropy_len( ctr_drbg_context *ctx,
+ size_t len );
+
+/**
+ * \brief Set the reseed interval
+ * (Default: CTR_DRBG_RESEED_INTERVAL)
+ *
+ * \param ctx CTR_DRBG context
+ * \param interval Reseed interval
+ */
+void ctr_drbg_set_reseed_interval( ctr_drbg_context *ctx,
+ int interval );
+
+/**
+ * \brief CTR_DRBG reseeding (extracts data from entropy source)
+ *
+ * \param ctx CTR_DRBG context
+ * \param additional Additional data to add to state
+ * \param len Length of additional data
+ *
+ * \return 0 if successful, or
+ * POLARSSL_ERR_CTR_DRBG_ENTROPY_SOURCE_FAILED
+ */
+int ctr_drbg_reseed( ctr_drbg_context *ctx,
+ unsigned char *additional, size_t len );
+
+/**
+ * \brief CTR_DRBG update state
+ *
+ * \param ctx CTR_DRBG context
+ * \param data Data to update with
+ *
+ * \return 0 if successful
+ */
+int ctr_drbg_update( ctr_drbg_context *ctx,
+ unsigned char data[CTR_DRBG_SEEDLEN] );
+
+/**
+ * \brief CTR_DRBG generate random with additional update input
+ *
+ * Note: Automatically reseeds if reseed_counter is reached.
+ *
+ * \param p_rng CTR_DRBG context
+ * \param output Buffer to fill
+ * \param output_len Length of the buffer
+ * \param additional Additional data to update with
+ * \param add_len Length of additional data
+ *
+ * \return 0 if successful, or
+ * POLARSSL_ERR_CTR_DRBG_ENTROPY_SOURCE_FAILED, or
+ * POLARSSL_ERR_CTR_DRBG_REQUEST_TOO_BIG
+ */
+int ctr_drbg_random_with_add( void *p_rng,
+ unsigned char *output, size_t output_len,
+ unsigned char *additional, size_t add_len );
+
+/**
+ * \brief CTR_DRBG generate random
+ *
+ * Note: Automatically reseeds if reseed_counter is reached.
+ *
+ * \param p_rng CTR_DRBG context
+ * \param output Buffer to fill
+ * \param output_len Length of the buffer
+ *
+ * \return 0 if successful, or
+ * POLARSSL_ERR_CTR_DRBG_ENTROPY_SOURCE_FAILED, or
+ * POLARSSL_ERR_CTR_DRBG_REQUEST_TOO_BIG
+ */
+int ctr_drbg_random( void *p_rng,
+ unsigned char *output, size_t output_len );
+
+/**
+ * \brief Checkup routine
+ *
+ * \return 0 if successful, or 1 if the test failed
+ */
+int ctr_drbg_self_test( int verbose );
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* ctr_drbg.h */
diff --git a/include/polarssl/error.h b/include/polarssl/error.h
index af2f331..7ef8a74 100644
--- a/include/polarssl/error.h
+++ b/include/polarssl/error.h
@@ -57,6 +57,7 @@
* PADLOCK 1 0x0030-0x0030
* DES 1 0x0032-0x0032
* NET 11 0x0040-0x0054
+ * CTR_DBRG 3 0x0034-0x0038
*
* High-level module nr (3 bits - 0x1...-0x8...)
* Name ID Nr of Errors