diff --git a/ChangeLog b/ChangeLog
index 7b50534..25f3b32 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -13,6 +13,11 @@
      Therefore, mbedtls_platform_zeroize() is moved to the platform module to
      facilitate testing and maintenance.
 
+Features
+   * Implement HKDF per RFC 5869. Contributed by Thomas Fossati.
+   * Add additional block mode, OFB (Output Feedback), to the AES module and
+     cipher abstraction module.
+
 = mbed TLS 2.9.0 branch released 2018-04-30
 
 Security
diff --git a/include/mbedtls/aes.h b/include/mbedtls/aes.h
index ea69781..65ab229 100644
--- a/include/mbedtls/aes.h
+++ b/include/mbedtls/aes.h
@@ -364,6 +364,46 @@
                     unsigned char *output );
 #endif /*MBEDTLS_CIPHER_MODE_CFB */
 
+#if defined(MBEDTLS_CIPHER_MODE_OFB)
+/**
+ * \brief This function performs an AES-OFB (Output Feedback Mode) encryption
+ *        or decryption operation.
+ *
+ *        For OFB, you must set up the context with mbedtls_aes_setkey_enc(),
+ *        regardless of whether you are performing an encryption or decryption
+ *        operation. This is because OFB mode uses the same key schedule for
+ *        encryption and decryption.
+ *
+ *        The OFB operation is identical for encryption or decryption, therefore
+ *        no operation mode needs to be specified.
+ *
+ * \note  Upon exit, the content of the IV is updated so that you can
+ *        call the same function again on the next
+ *        block(s) of data and get the same result as if it was
+ *        encrypted in one call. This allows a "streaming" usage.
+ *        If you need to retain the contents of the
+ *        IV, you must either save it manually or use the cipher
+ *        module instead.
+ *
+ *
+ * \param ctx      The AES context to use for encryption or decryption.
+ * \param length   The length of the input data.
+ * \param iv_off   The offset in IV (updated after use).
+ * \param iv       The initialization vector (updated after use).
+ * \param input    The buffer holding the input data.
+ * \param output   The buffer holding the output data.
+ *
+ * \return         \c 0 on success.
+ */
+int mbedtls_aes_crypt_ofb( mbedtls_aes_context *ctx,
+                       size_t length,
+                       size_t *iv_off,
+                       unsigned char iv[16],
+                       const unsigned char *input,
+                       unsigned char *output );
+
+#endif /* MBEDTLS_CIPHER_MODE_OFB */
+
 #if defined(MBEDTLS_CIPHER_MODE_CTR)
 /**
  * \brief      This function performs an AES-CTR encryption or decryption
diff --git a/include/mbedtls/check_config.h b/include/mbedtls/check_config.h
index be80332..4689f3a 100644
--- a/include/mbedtls/check_config.h
+++ b/include/mbedtls/check_config.h
@@ -4,7 +4,7 @@
  * \brief Consistency checks for configuration options
  */
 /*
- *  Copyright (C) 2006-2016, ARM Limited, All Rights Reserved
+ *  Copyright (C) 2006-2018, ARM Limited, All Rights Reserved
  *  SPDX-License-Identifier: Apache-2.0
  *
  *  Licensed under the Apache License, Version 2.0 (the "License"); you may
@@ -191,6 +191,10 @@
 #error "MBEDTLS_HAVEGE_C defined, but not all prerequisites"
 #endif
 
+#if defined(MBEDTLS_HKDF_C) && !defined(MBEDTLS_MD_C)
+#error "MBEDTLS_HKDF_C defined, but not all prerequisites"
+#endif
+
 #if defined(MBEDTLS_HMAC_DRBG_C) && !defined(MBEDTLS_MD_C)
 #error "MBEDTLS_HMAC_DRBG_C defined, but not all prerequisites"
 #endif
diff --git a/include/mbedtls/cipher.h b/include/mbedtls/cipher.h
index 2789393..f588b14 100644
--- a/include/mbedtls/cipher.h
+++ b/include/mbedtls/cipher.h
@@ -145,6 +145,9 @@
     MBEDTLS_CIPHER_CAMELLIA_128_CCM,     /**< Camellia cipher with 128-bit CCM mode. */
     MBEDTLS_CIPHER_CAMELLIA_192_CCM,     /**< Camellia cipher with 192-bit CCM mode. */
     MBEDTLS_CIPHER_CAMELLIA_256_CCM,     /**< Camellia cipher with 256-bit CCM mode. */
+    MBEDTLS_CIPHER_AES_128_OFB,          /**< AES 128-bit cipher in OFB mode. */
+    MBEDTLS_CIPHER_AES_192_OFB,          /**< AES 192-bit cipher in OFB mode. */
+    MBEDTLS_CIPHER_AES_256_OFB,          /**< AES 256-bit cipher in OFB mode. */
     MBEDTLS_CIPHER_AES_128_XTS,          /**< AES 128-bit cipher in XTS block mode. */
     MBEDTLS_CIPHER_AES_256_XTS,          /**< AES 256-bit cipher in XTS block mode. */
 } mbedtls_cipher_type_t;
@@ -155,7 +158,7 @@
     MBEDTLS_MODE_ECB,                    /**< The ECB cipher mode. */
     MBEDTLS_MODE_CBC,                    /**< The CBC cipher mode. */
     MBEDTLS_MODE_CFB,                    /**< The CFB cipher mode. */
-    MBEDTLS_MODE_OFB,                    /**< The OFB cipher mode - unsupported. */
+    MBEDTLS_MODE_OFB,                    /**< The OFB cipher mode. */
     MBEDTLS_MODE_CTR,                    /**< The CTR cipher mode. */
     MBEDTLS_MODE_GCM,                    /**< The GCM cipher mode. */
     MBEDTLS_MODE_STREAM,                 /**< The stream cipher mode. */
diff --git a/include/mbedtls/cipher_internal.h b/include/mbedtls/cipher_internal.h
index d4c7a59..95b7ef7 100644
--- a/include/mbedtls/cipher_internal.h
+++ b/include/mbedtls/cipher_internal.h
@@ -59,11 +59,20 @@
 
 #if defined(MBEDTLS_CIPHER_MODE_CFB)
     /** Encrypt using CFB (Full length) */
+
     int (*cfb_func)( void *ctx, mbedtls_operation_t mode, size_t length, size_t *iv_off,
                      unsigned char *iv, const unsigned char *input,
                      unsigned char *output );
 #endif
 
+#if defined(MBEDTLS_CIPHER_MODE_OFB)
+    /** Encrypt using OFB (Full length) */
+    int (*ofb_func)( void *ctx, size_t length, size_t *iv_off,
+                     unsigned char *iv,
+                     const unsigned char *input,
+                     unsigned char *output );
+#endif
+
 #if defined(MBEDTLS_CIPHER_MODE_CTR)
     /** Encrypt using CTR */
     int (*ctr_func)( void *ctx, size_t length, size_t *nc_off,
diff --git a/include/mbedtls/config.h b/include/mbedtls/config.h
index fbbdbee..337e136 100644
--- a/include/mbedtls/config.h
+++ b/include/mbedtls/config.h
@@ -8,7 +8,7 @@
  *  memory footprint.
  */
 /*
- *  Copyright (C) 2006-2015, ARM Limited, All Rights Reserved
+ *  Copyright (C) 2006-2018, ARM Limited, All Rights Reserved
  *  SPDX-License-Identifier: Apache-2.0
  *
  *  Licensed under the Apache License, Version 2.0 (the "License"); you may
@@ -496,6 +496,13 @@
 #define MBEDTLS_CIPHER_MODE_CBC
 
 /**
+ * \def MBEDTLS_CIPHER_MODE_OFB
+ *
+ * Enable Output Feedback mode (OFB) for symmetric ciphers.
+ */
+#define MBEDTLS_CIPHER_MODE_OFB
+
+/**
  * \def MBEDTLS_CIPHER_MODE_CFB
  *
  * Enable Cipher Feedback mode (CFB) for symmetric ciphers.
@@ -2100,6 +2107,21 @@
 //#define MBEDTLS_HAVEGE_C
 
 /**
+ * \def MBEDTLS_HKDF_C
+ *
+ * Enable HKDF algorithm.
+ *
+ * Module:  library/hkdf.c
+ * Caller:
+
+ * Requires: MBEDTLS_MD_C
+ *
+ * This module adds support for the Hashed Message Authentication Code
+ * (HMAC)-based key derivation function (HKDF).
+ */
+#define MBEDTLS_HKDF_C
+
+/**
  * \def MBEDTLS_HMAC_DRBG_C
  *
  * Enable the HMAC_DRBG random generator.
diff --git a/include/mbedtls/error.h b/include/mbedtls/error.h
index 8b4d3a8..a3d6bba 100644
--- a/include/mbedtls/error.h
+++ b/include/mbedtls/error.h
@@ -4,7 +4,7 @@
  * \brief Error to string translation
  */
 /*
- *  Copyright (C) 2006-2015, ARM Limited, All Rights Reserved
+ *  Copyright (C) 2006-2018, ARM Limited, All Rights Reserved
  *  SPDX-License-Identifier: Apache-2.0
  *
  *  Licensed under the Apache License, Version 2.0 (the "License"); you may
@@ -88,6 +88,7 @@
  * RSA       4   11
  * ECP       4   9 (Started from top)
  * MD        5   5
+ * HKDF      5   1
  * CIPHER    6   8
  * SSL       6   17 (Started from top)
  * SSL       7   31
diff --git a/include/mbedtls/hkdf.h b/include/mbedtls/hkdf.h
new file mode 100644
index 0000000..419c34e
--- /dev/null
+++ b/include/mbedtls/hkdf.h
@@ -0,0 +1,115 @@
+/**
+ * \file hkdf.h
+ *
+ * \brief The HMAC-based Extract-and-Expand Key Derivation Function (HKDF)
+ *
+ */
+/*
+ * Copyright (C) 2016-2018, ARM Limited, All Rights Reserved
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License"); you may
+ * not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ * This file is part of mbed TLS (https://tls.mbed.org)
+ */
+#ifndef MBEDTLS_HKDF_H
+#define MBEDTLS_HKDF_H
+
+#include "md.h"
+
+/**
+ *  \name HKDF Error codes
+ *  \{
+ */
+#define MBEDTLS_ERR_HKDF_BAD_PARAM  -0x5300  /**< Bad parameter */
+/* \} name */
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/**
+ *  \brief  HMAC-based Extract-and-Expand Key Derivation Function
+ *
+ *  \param  md        a hash function; md.size denotes the length of the hash
+ *                    function output in bytes
+ *  \param  salt      optional salt value (a non-secret random value);
+ *                    if not provided, it is set to a string of md.size zeros.
+ *  \param  salt_len  length in bytes of the optional \p salt
+ *  \param  ikm       input keying material
+ *  \param  ikm_len   length in bytes of \p ikm
+ *  \param  info      optional context and application specific information
+ *                    (can be a zero-length string)
+ *  \param  info_len  length of \p info in bytes
+ *  \param  okm       output keying material (of \p okm_len bytes)
+ *  \param  okm_len   length of output keying material in octets
+ *                    (<= 255*md.size)
+ *
+ *  \return 0 on success or one of the failure codes from mbedtls_hkdf_extract
+ *          or mbedtls_hkdf_expand
+ */
+int mbedtls_hkdf( const mbedtls_md_info_t *md, const unsigned char *salt,
+                  size_t salt_len, const unsigned char *ikm, size_t ikm_len,
+                  const unsigned char *info, size_t info_len,
+                  unsigned char *okm, size_t okm_len );
+
+/**
+ *  \brief  Take the input keying material \p ikm and extract from it a
+ *          fixed-length pseudorandom key \p prk
+ *
+ *  \param       md        a hash function; md.size denotes the length of the
+ *                         hash function output in bytes
+ *  \param       salt      optional salt value (a non-secret random value);
+ *                         if not provided, it is set to a string of md.size
+ *                         zeros.
+ *  \param       salt_len  length in bytes of the optional \p salt
+ *  \param       ikm       input keying material
+ *  \param       ikm_len   length in bytes of \p ikm
+ *  \param[out]  prk       a pseudorandom key of md.size bytes
+ *
+ *  \return 0 on success, MBEDTLS_ERR_HKDF_BAD_PARAM or one of mbedtls_md_*
+ *          error codes on failure
+ */
+int mbedtls_hkdf_extract( const mbedtls_md_info_t *md,
+                          const unsigned char *salt, size_t salt_len,
+                          const unsigned char *ikm, size_t ikm_len,
+                          unsigned char *prk );
+
+/**
+ *  \brief  Expand the supplied \p prk into several additional pseudorandom keys
+ *          (the output of the KDF).
+ *
+ *  \param  md          a hash function; md.size denotes the length of the hash
+ *                      function output in bytes
+ *  \param  prk         a pseudorandom key of at least md.size bytes; usually,
+ *                      the output from the extract step
+ *  \param  prk_len     length of \p prk in bytes
+ *  \param  info        optional context and application specific information
+ *                      (can be a zero-length string)
+ *  \param  info_len    length of \p info in bytes
+ *  \param  okm         output keying material (of \p okm_len bytes)
+ *  \param  okm_len     length of output keying material in octets
+ *                      (<= 255*md.size)
+ *
+ *  \return 0 on success, MBEDTLS_ERR_HKDF_BAD_PARAM or a failure code from the
+ *          mbedtls_md_* family
+ */
+int mbedtls_hkdf_expand( const mbedtls_md_info_t *md, const unsigned char *prk,
+                         size_t prk_len, const unsigned char *info,
+                         size_t info_len, unsigned char *okm, size_t okm_len );
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* hkdf.h */
diff --git a/library/CMakeLists.txt b/library/CMakeLists.txt
index 6177ca2..b730d08 100644
--- a/library/CMakeLists.txt
+++ b/library/CMakeLists.txt
@@ -29,6 +29,7 @@
     error.c
     gcm.c
     havege.c
+    hkdf.c
     hmac_drbg.c
     md.c
     md2.c
diff --git a/library/Makefile b/library/Makefile
index b155c72..5721d7e 100644
--- a/library/Makefile
+++ b/library/Makefile
@@ -56,6 +56,7 @@
 		ecjpake.o	ecp.o				\
 		ecp_curves.o	entropy.o	entropy_poll.o	\
 		error.o		gcm.o		havege.o	\
+		hkdf.o						\
 		hmac_drbg.o	md.o		md2.o		\
 		md4.o		md5.o		md_wrap.o	\
 		memory_buffer_alloc.o		oid.o		\
diff --git a/library/aes.c b/library/aes.c
index 5752fb3..59c5165 100644
--- a/library/aes.c
+++ b/library/aes.c
@@ -1114,7 +1114,41 @@
 
     return( 0 );
 }
-#endif /*MBEDTLS_CIPHER_MODE_CFB */
+#endif /* MBEDTLS_CIPHER_MODE_CFB */
+
+#if defined(MBEDTLS_CIPHER_MODE_OFB)
+/*
+ * AES-OFB (Output Feedback Mode) buffer encryption/decryption
+ */
+int mbedtls_aes_crypt_ofb( mbedtls_aes_context *ctx,
+                            size_t length,
+                            size_t *iv_off,
+                            unsigned char iv[16],
+                            const unsigned char *input,
+                            unsigned char *output )
+{
+    int ret = 0;
+    size_t n = *iv_off;
+
+    while( length-- )
+    {
+        if( n == 0 )
+        {
+            ret = mbedtls_aes_crypt_ecb( ctx, MBEDTLS_AES_ENCRYPT, iv, iv );
+            if( ret != 0 )
+                goto exit;
+        }
+        *output++ =  *input++ ^ iv[n];
+
+        n = ( n + 1 ) & 0x0F;
+    }
+
+    *iv_off = n;
+
+exit:
+    return( ret );
+}
+#endif /* MBEDTLS_CIPHER_MODE_OFB */
 
 #if defined(MBEDTLS_CIPHER_MODE_CTR)
 /*
@@ -1394,6 +1428,72 @@
 };
 #endif /* MBEDTLS_CIPHER_MODE_CFB */
 
+#if defined(MBEDTLS_CIPHER_MODE_OFB)
+/*
+ * AES-OFB test vectors from:
+ *
+ * http://csrc.nist.gov/publications/nistpubs/800-38a/sp800-38a.pdf
+ */
+static const unsigned char aes_test_ofb_key[3][32] =
+{
+    { 0x2B, 0x7E, 0x15, 0x16, 0x28, 0xAE, 0xD2, 0xA6,
+      0xAB, 0xF7, 0x15, 0x88, 0x09, 0xCF, 0x4F, 0x3C },
+    { 0x8E, 0x73, 0xB0, 0xF7, 0xDA, 0x0E, 0x64, 0x52,
+      0xC8, 0x10, 0xF3, 0x2B, 0x80, 0x90, 0x79, 0xE5,
+      0x62, 0xF8, 0xEA, 0xD2, 0x52, 0x2C, 0x6B, 0x7B },
+    { 0x60, 0x3D, 0xEB, 0x10, 0x15, 0xCA, 0x71, 0xBE,
+      0x2B, 0x73, 0xAE, 0xF0, 0x85, 0x7D, 0x77, 0x81,
+      0x1F, 0x35, 0x2C, 0x07, 0x3B, 0x61, 0x08, 0xD7,
+      0x2D, 0x98, 0x10, 0xA3, 0x09, 0x14, 0xDF, 0xF4 }
+};
+
+static const unsigned char aes_test_ofb_iv[16] =
+{
+    0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07,
+    0x08, 0x09, 0x0A, 0x0B, 0x0C, 0x0D, 0x0E, 0x0F
+};
+
+static const unsigned char aes_test_ofb_pt[64] =
+{
+    0x6B, 0xC1, 0xBE, 0xE2, 0x2E, 0x40, 0x9F, 0x96,
+    0xE9, 0x3D, 0x7E, 0x11, 0x73, 0x93, 0x17, 0x2A,
+    0xAE, 0x2D, 0x8A, 0x57, 0x1E, 0x03, 0xAC, 0x9C,
+    0x9E, 0xB7, 0x6F, 0xAC, 0x45, 0xAF, 0x8E, 0x51,
+    0x30, 0xC8, 0x1C, 0x46, 0xA3, 0x5C, 0xE4, 0x11,
+    0xE5, 0xFB, 0xC1, 0x19, 0x1A, 0x0A, 0x52, 0xEF,
+    0xF6, 0x9F, 0x24, 0x45, 0xDF, 0x4F, 0x9B, 0x17,
+    0xAD, 0x2B, 0x41, 0x7B, 0xE6, 0x6C, 0x37, 0x10
+};
+
+static const unsigned char aes_test_ofb_ct[3][64] =
+{
+    { 0x3B, 0x3F, 0xD9, 0x2E, 0xB7, 0x2D, 0xAD, 0x20,
+      0x33, 0x34, 0x49, 0xF8, 0xE8, 0x3C, 0xFB, 0x4A,
+      0x77, 0x89, 0x50, 0x8d, 0x16, 0x91, 0x8f, 0x03,
+      0xf5, 0x3c, 0x52, 0xda, 0xc5, 0x4e, 0xd8, 0x25,
+      0x97, 0x40, 0x05, 0x1e, 0x9c, 0x5f, 0xec, 0xf6,
+      0x43, 0x44, 0xf7, 0xa8, 0x22, 0x60, 0xed, 0xcc,
+      0x30, 0x4c, 0x65, 0x28, 0xf6, 0x59, 0xc7, 0x78,
+      0x66, 0xa5, 0x10, 0xd9, 0xc1, 0xd6, 0xae, 0x5e },
+    { 0xCD, 0xC8, 0x0D, 0x6F, 0xDD, 0xF1, 0x8C, 0xAB,
+      0x34, 0xC2, 0x59, 0x09, 0xC9, 0x9A, 0x41, 0x74,
+      0xfc, 0xc2, 0x8b, 0x8d, 0x4c, 0x63, 0x83, 0x7c,
+      0x09, 0xe8, 0x17, 0x00, 0xc1, 0x10, 0x04, 0x01,
+      0x8d, 0x9a, 0x9a, 0xea, 0xc0, 0xf6, 0x59, 0x6f,
+      0x55, 0x9c, 0x6d, 0x4d, 0xaf, 0x59, 0xa5, 0xf2,
+      0x6d, 0x9f, 0x20, 0x08, 0x57, 0xca, 0x6c, 0x3e,
+      0x9c, 0xac, 0x52, 0x4b, 0xd9, 0xac, 0xc9, 0x2a },
+    { 0xDC, 0x7E, 0x84, 0xBF, 0xDA, 0x79, 0x16, 0x4B,
+      0x7E, 0xCD, 0x84, 0x86, 0x98, 0x5D, 0x38, 0x60,
+      0x4f, 0xeb, 0xdc, 0x67, 0x40, 0xd2, 0x0b, 0x3a,
+      0xc8, 0x8f, 0x6a, 0xd8, 0x2a, 0x4f, 0xb0, 0x8d,
+      0x71, 0xab, 0x47, 0xa0, 0x86, 0xe8, 0x6e, 0xed,
+      0xf3, 0x9d, 0x1c, 0x5b, 0xba, 0x97, 0xc4, 0x08,
+      0x01, 0x26, 0x14, 0x1d, 0x67, 0xf3, 0x7b, 0xe8,
+      0x53, 0x8f, 0x5a, 0x8b, 0xe7, 0x40, 0xe4, 0x84 }
+};
+#endif /* MBEDTLS_CIPHER_MODE_OFB */
+
 #if defined(MBEDTLS_CIPHER_MODE_CTR)
 /*
  * AES-CTR test vectors from:
@@ -1756,6 +1856,69 @@
         mbedtls_printf( "\n" );
 #endif /* MBEDTLS_CIPHER_MODE_CFB */
 
+#if defined(MBEDTLS_CIPHER_MODE_OFB)
+    /*
+     * OFB mode
+     */
+    for( i = 0; i < 6; i++ )
+    {
+        u = i >> 1;
+        keybits = 128 + u * 64;
+        mode = i & 1;
+
+        if( verbose != 0 )
+            mbedtls_printf( "  AES-OFB-%3d (%s): ", keybits,
+                            ( mode == MBEDTLS_AES_DECRYPT ) ? "dec" : "enc" );
+
+        memcpy( iv,  aes_test_ofb_iv, 16 );
+        memcpy( key, aes_test_ofb_key[u], keybits / 8 );
+
+        offset = 0;
+        ret = mbedtls_aes_setkey_enc( &ctx, key, keybits );
+        /*
+         * AES-192 is an optional feature that may be unavailable when
+         * there is an alternative underlying implementation i.e. when
+         * MBEDTLS_AES_ALT is defined.
+         */
+        if( ret == MBEDTLS_ERR_AES_FEATURE_UNAVAILABLE && keybits == 192 )
+        {
+            mbedtls_printf( "skipped\n" );
+            continue;
+        }
+        else if( ret != 0 )
+        {
+            goto exit;
+        }
+
+        if( mode == MBEDTLS_AES_DECRYPT )
+        {
+            memcpy( buf, aes_test_ofb_ct[u], 64 );
+            aes_tests = aes_test_ofb_pt;
+        }
+        else
+        {
+            memcpy( buf, aes_test_ofb_pt, 64 );
+            aes_tests = aes_test_ofb_ct[u];
+        }
+
+        ret = mbedtls_aes_crypt_ofb( &ctx, 64, &offset, iv, buf, buf );
+        if( ret != 0 )
+            goto exit;
+
+        if( memcmp( buf, aes_tests, 64 ) != 0 )
+        {
+            ret = 1;
+            goto exit;
+        }
+
+        if( verbose != 0 )
+            mbedtls_printf( "passed\n" );
+    }
+
+    if( verbose != 0 )
+        mbedtls_printf( "\n" );
+#endif /* MBEDTLS_CIPHER_MODE_OFB */
+
 #if defined(MBEDTLS_CIPHER_MODE_CTR)
     /*
      * CTR mode
diff --git a/library/cipher.c b/library/cipher.c
index 4f12b72..74fd950 100644
--- a/library/cipher.c
+++ b/library/cipher.c
@@ -191,10 +191,11 @@
     ctx->operation = operation;
 
     /*
-     * For CFB and CTR mode always use the encryption key schedule
+     * For OFB, CFB and CTR mode always use the encryption key schedule
      */
     if( MBEDTLS_ENCRYPT == operation ||
         MBEDTLS_MODE_CFB == ctx->cipher_info->mode ||
+        MBEDTLS_MODE_OFB == ctx->cipher_info->mode ||
         MBEDTLS_MODE_CTR == ctx->cipher_info->mode )
     {
         return ctx->cipher_info->base->setkey_enc_func( ctx->cipher_ctx, key,
@@ -424,6 +425,21 @@
     }
 #endif /* MBEDTLS_CIPHER_MODE_CFB */
 
+#if defined(MBEDTLS_CIPHER_MODE_OFB)
+    if( ctx->cipher_info->mode == MBEDTLS_MODE_OFB )
+    {
+        if( 0 != ( ret = ctx->cipher_info->base->ofb_func( ctx->cipher_ctx,
+                ilen, &ctx->unprocessed_len, ctx->iv, input, output ) ) )
+        {
+            return( ret );
+        }
+
+        *olen = ilen;
+
+        return( 0 );
+    }
+#endif /* MBEDTLS_CIPHER_MODE_OFB */
+
 #if defined(MBEDTLS_CIPHER_MODE_CTR)
     if( ctx->cipher_info->mode == MBEDTLS_MODE_CTR )
     {
@@ -660,6 +676,7 @@
     *olen = 0;
 
     if( MBEDTLS_MODE_CFB == ctx->cipher_info->mode ||
+        MBEDTLS_MODE_OFB == ctx->cipher_info->mode ||
         MBEDTLS_MODE_CTR == ctx->cipher_info->mode ||
         MBEDTLS_MODE_GCM == ctx->cipher_info->mode ||
         MBEDTLS_MODE_XTS == ctx->cipher_info->mode ||
diff --git a/library/cipher_wrap.c b/library/cipher_wrap.c
index 070f1d8..a58a5c7 100644
--- a/library/cipher_wrap.c
+++ b/library/cipher_wrap.c
@@ -138,6 +138,15 @@
 }
 #endif /* MBEDTLS_CIPHER_MODE_CFB */
 
+#if defined(MBEDTLS_CIPHER_MODE_OFB)
+static int aes_crypt_ofb_wrap( void *ctx, size_t length, size_t *iv_off,
+        unsigned char *iv, const unsigned char *input, unsigned char *output )
+{
+    return mbedtls_aes_crypt_ofb( (mbedtls_aes_context *) ctx, length, iv_off,
+                                    iv, input, output );
+}
+#endif /* MBEDTLS_CIPHER_MODE_OFB */
+
 #if defined(MBEDTLS_CIPHER_MODE_CTR)
 static int aes_crypt_ctr_wrap( void *ctx, size_t length, size_t *nc_off,
         unsigned char *nonce_counter, unsigned char *stream_block,
@@ -214,6 +223,9 @@
 #if defined(MBEDTLS_CIPHER_MODE_CFB)
     aes_crypt_cfb128_wrap,
 #endif
+#if defined(MBEDTLS_CIPHER_MODE_OFB)
+    aes_crypt_ofb_wrap,
+#endif
 #if defined(MBEDTLS_CIPHER_MODE_CTR)
     aes_crypt_ctr_wrap,
 #endif
@@ -332,6 +344,41 @@
 };
 #endif /* MBEDTLS_CIPHER_MODE_CFB */
 
+#if defined(MBEDTLS_CIPHER_MODE_OFB)
+static const mbedtls_cipher_info_t aes_128_ofb_info = {
+    MBEDTLS_CIPHER_AES_128_OFB,
+    MBEDTLS_MODE_OFB,
+    128,
+    "AES-128-OFB",
+    16,
+    0,
+    16,
+    &aes_info
+};
+
+static const mbedtls_cipher_info_t aes_192_ofb_info = {
+    MBEDTLS_CIPHER_AES_192_OFB,
+    MBEDTLS_MODE_OFB,
+    192,
+    "AES-192-OFB",
+    16,
+    0,
+    16,
+    &aes_info
+};
+
+static const mbedtls_cipher_info_t aes_256_ofb_info = {
+    MBEDTLS_CIPHER_AES_256_OFB,
+    MBEDTLS_MODE_OFB,
+    256,
+    "AES-256-OFB",
+    16,
+    0,
+    16,
+    &aes_info
+};
+#endif /* MBEDTLS_CIPHER_MODE_OFB */
+
 #if defined(MBEDTLS_CIPHER_MODE_CTR)
 static const mbedtls_cipher_info_t aes_128_ctr_info = {
     MBEDTLS_CIPHER_AES_128_CTR,
@@ -412,6 +459,9 @@
 #if defined(MBEDTLS_CIPHER_MODE_CFB)
     NULL,
 #endif
+#if defined(MBEDTLS_CIPHER_MODE_OFB)
+    NULL,
+#endif
 #if defined(MBEDTLS_CIPHER_MODE_CTR)
     NULL,
 #endif
@@ -467,6 +517,9 @@
 #if defined(MBEDTLS_CIPHER_MODE_CFB)
     NULL,
 #endif
+#if defined(MBEDTLS_CIPHER_MODE_OFB)
+    NULL,
+#endif
 #if defined(MBEDTLS_CIPHER_MODE_CTR)
     NULL,
 #endif
@@ -533,6 +586,9 @@
 #if defined(MBEDTLS_CIPHER_MODE_CFB)
     NULL,
 #endif
+#if defined(MBEDTLS_CIPHER_MODE_OFB)
+    NULL,
+#endif
 #if defined(MBEDTLS_CIPHER_MODE_CTR)
     NULL,
 #endif
@@ -663,6 +719,9 @@
 #if defined(MBEDTLS_CIPHER_MODE_CFB)
     camellia_crypt_cfb128_wrap,
 #endif
+#if defined(MBEDTLS_CIPHER_MODE_OFB)
+    NULL,
+#endif
 #if defined(MBEDTLS_CIPHER_MODE_CTR)
     camellia_crypt_ctr_wrap,
 #endif
@@ -833,6 +892,9 @@
 #if defined(MBEDTLS_CIPHER_MODE_CFB)
     NULL,
 #endif
+#if defined(MBEDTLS_CIPHER_MODE_OFB)
+    NULL,
+#endif
 #if defined(MBEDTLS_CIPHER_MODE_CTR)
     NULL,
 #endif
@@ -899,6 +961,9 @@
 #if defined(MBEDTLS_CIPHER_MODE_CFB)
     NULL,
 #endif
+#if defined(MBEDTLS_CIPHER_MODE_OFB)
+    NULL,
+#endif
 #if defined(MBEDTLS_CIPHER_MODE_CTR)
     NULL,
 #endif
@@ -1078,6 +1143,9 @@
 #if defined(MBEDTLS_CIPHER_MODE_CFB)
     NULL,
 #endif
+#if defined(MBEDTLS_CIPHER_MODE_OFB)
+    NULL,
+#endif
 #if defined(MBEDTLS_CIPHER_MODE_CTR)
     NULL,
 #endif
@@ -1126,6 +1194,9 @@
 #if defined(MBEDTLS_CIPHER_MODE_CFB)
     NULL,
 #endif
+#if defined(MBEDTLS_CIPHER_MODE_OFB)
+    NULL,
+#endif
 #if defined(MBEDTLS_CIPHER_MODE_CTR)
     NULL,
 #endif
@@ -1174,6 +1245,9 @@
 #if defined(MBEDTLS_CIPHER_MODE_CFB)
     NULL,
 #endif
+#if defined(MBEDTLS_CIPHER_MODE_OFB)
+    NULL,
+#endif
 #if defined(MBEDTLS_CIPHER_MODE_CTR)
     NULL,
 #endif
@@ -1286,6 +1360,9 @@
 #if defined(MBEDTLS_CIPHER_MODE_CFB)
     blowfish_crypt_cfb64_wrap,
 #endif
+#if defined(MBEDTLS_CIPHER_MODE_OFB)
+    NULL,
+#endif
 #if defined(MBEDTLS_CIPHER_MODE_CTR)
     blowfish_crypt_ctr_wrap,
 #endif
@@ -1399,6 +1476,9 @@
 #if defined(MBEDTLS_CIPHER_MODE_CFB)
     NULL,
 #endif
+#if defined(MBEDTLS_CIPHER_MODE_OFB)
+    NULL,
+#endif
 #if defined(MBEDTLS_CIPHER_MODE_CTR)
     NULL,
 #endif
@@ -1465,6 +1545,9 @@
 #if defined(MBEDTLS_CIPHER_MODE_CFB)
     NULL,
 #endif
+#if defined(MBEDTLS_CIPHER_MODE_OFB)
+    NULL,
+#endif
 #if defined(MBEDTLS_CIPHER_MODE_CTR)
     NULL,
 #endif
@@ -1508,6 +1591,11 @@
     { MBEDTLS_CIPHER_AES_192_CFB128,       &aes_192_cfb128_info },
     { MBEDTLS_CIPHER_AES_256_CFB128,       &aes_256_cfb128_info },
 #endif
+#if defined(MBEDTLS_CIPHER_MODE_OFB)
+    { MBEDTLS_CIPHER_AES_128_OFB,          &aes_128_ofb_info },
+    { MBEDTLS_CIPHER_AES_192_OFB,          &aes_192_ofb_info },
+    { MBEDTLS_CIPHER_AES_256_OFB,          &aes_256_ofb_info },
+#endif
 #if defined(MBEDTLS_CIPHER_MODE_CTR)
     { MBEDTLS_CIPHER_AES_128_CTR,          &aes_128_ctr_info },
     { MBEDTLS_CIPHER_AES_192_CTR,          &aes_192_ctr_info },
diff --git a/library/error.c b/library/error.c
index 222d85b..8dd90b2 100644
--- a/library/error.c
+++ b/library/error.c
@@ -101,6 +101,10 @@
 #include "mbedtls/gcm.h"
 #endif
 
+#if defined(MBEDTLS_HKDF_C)
+#include "mbedtls/hkdf.h"
+#endif
+
 #if defined(MBEDTLS_HMAC_DRBG_C)
 #include "mbedtls/hmac_drbg.h"
 #endif
@@ -698,6 +702,11 @@
         mbedtls_snprintf( buf, buflen, "GCM - Bad input parameters to function" );
 #endif /* MBEDTLS_GCM_C */
 
+#if defined(MBEDTLS_HKDF_C)
+    if( use_ret == -(MBEDTLS_ERR_HKDF_BAD_PARAM) )
+        mbedtls_snprintf( buf, buflen, "HKDF - Bad parameter" );
+#endif /* MBEDTLS_HKDF_C */
+
 #if defined(MBEDTLS_HMAC_DRBG_C)
     if( use_ret == -(MBEDTLS_ERR_HMAC_DRBG_REQUEST_TOO_BIG) )
         mbedtls_snprintf( buf, buflen, "HMAC_DRBG - Too many random requested in single call" );
diff --git a/library/hkdf.c b/library/hkdf.c
new file mode 100644
index 0000000..ded555c
--- /dev/null
+++ b/library/hkdf.c
@@ -0,0 +1,164 @@
+/*
+ *  HKDF implementation -- RFC 5869
+ *
+ *  Copyright (C) 2016-2017, ARM Limited, All Rights Reserved
+ *  SPDX-License-Identifier: Apache-2.0
+ *
+ *  Licensed under the Apache License, Version 2.0 (the "License"); you may
+ *  not use this file except in compliance with the License.
+ *  You may obtain a copy of the License at
+ *
+ *  http://www.apache.org/licenses/LICENSE-2.0
+ *
+ *  Unless required by applicable law or agreed to in writing, software
+ *  distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ *  WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *  See the License for the specific language governing permissions and
+ *  limitations under the License.
+ *
+ *  This file is part of mbed TLS (https://tls.mbed.org)
+ */
+#if !defined(MBEDTLS_CONFIG_FILE)
+#include "mbedtls/config.h"
+#else
+#include MBEDTLS_CONFIG_FILE
+#endif
+
+#if defined(MBEDTLS_HKDF_C)
+
+#include <string.h>
+#include "mbedtls/hkdf.h"
+#include "mbedtls/platform_util.h"
+
+/* HKDF-Extract + HKDF-Expand */
+int mbedtls_hkdf( const mbedtls_md_info_t *md, const unsigned char *salt,
+                  size_t salt_len, const unsigned char *ikm, size_t ikm_len,
+                  const unsigned char *info, size_t info_len,
+                  unsigned char *okm, size_t okm_len )
+{
+    int ret;
+    unsigned char prk[MBEDTLS_MD_MAX_SIZE];
+
+    ret = mbedtls_hkdf_extract( md, salt, salt_len, ikm, ikm_len, prk );
+
+    if ( ret == 0 ) {
+        ret = mbedtls_hkdf_expand( md, prk, mbedtls_md_get_size(md), info, info_len, okm, okm_len );
+    }
+
+    mbedtls_platform_zeroize( prk, sizeof( prk ) );
+
+    return( ret );
+}
+
+/* HKDF-Extract(salt, IKM) -> PRK */
+int mbedtls_hkdf_extract( const mbedtls_md_info_t *md,
+                          const unsigned char *salt, size_t salt_len,
+                          const unsigned char *ikm, size_t ikm_len,
+                          unsigned char *prk )
+{
+    unsigned char null_salt[MBEDTLS_MD_MAX_SIZE] = { '\0' };
+
+    if ( salt == NULL ) {
+        size_t hash_len;
+
+        hash_len = mbedtls_md_get_size( md );
+
+        if ( hash_len == 0 ) {
+            return MBEDTLS_ERR_HKDF_BAD_PARAM;
+        }
+
+        salt = null_salt;
+        salt_len = hash_len;
+    }
+
+    return( mbedtls_md_hmac( md, salt, salt_len, ikm, ikm_len, prk ) );
+}
+
+/* HKDF-Expand(PRK, info, L) -> OKM */
+int mbedtls_hkdf_expand( const mbedtls_md_info_t *md, const unsigned char *prk,
+                         size_t prk_len, const unsigned char *info,
+                         size_t info_len, unsigned char *okm, size_t okm_len )
+{
+    size_t hash_len;
+    size_t where = 0;
+    size_t N;
+    size_t T_len = 0;
+    size_t i;
+    int ret = 0;
+    mbedtls_md_context_t ctx;
+    unsigned char T[MBEDTLS_MD_MAX_SIZE];
+
+    if ( okm == NULL ) {
+        return( MBEDTLS_ERR_HKDF_BAD_PARAM );
+    }
+
+    hash_len = mbedtls_md_get_size(md);
+
+    if ( (prk_len < hash_len) || (hash_len == 0) ) {
+        return( MBEDTLS_ERR_HKDF_BAD_PARAM );
+    }
+
+    if ( info == NULL ) {
+        info = (const unsigned char *) "";
+        info_len = 0;
+    }
+
+    N = okm_len / hash_len;
+
+    if ( (okm_len % hash_len) != 0 ) {
+        N++;
+    }
+
+    if ( N > 255 ) {
+        return( MBEDTLS_ERR_HKDF_BAD_PARAM );
+    }
+
+    mbedtls_md_init( &ctx );
+
+    if ( (ret = mbedtls_md_setup( &ctx, md, 1) ) != 0 ) {
+        goto exit;
+    }
+
+    /* Section 2.3. */
+    for ( i = 1; i <= N; i++ ) {
+        unsigned char c = i & 0xff;
+
+        ret = mbedtls_md_hmac_starts( &ctx, prk, prk_len );
+        if ( ret != 0 ) {
+            goto exit;
+        }
+
+        ret = mbedtls_md_hmac_update( &ctx, T, T_len );
+        if ( ret != 0 ) {
+            goto exit;
+        }
+
+        ret = mbedtls_md_hmac_update( &ctx, info, info_len );
+        if ( ret != 0 ) {
+            goto exit;
+        }
+
+        /* The constant concatenated to the end of each T(n) is a single octet.
+         * */
+        ret = mbedtls_md_hmac_update( &ctx, &c, 1 );
+        if ( ret != 0 ) {
+            goto exit;
+        }
+
+        ret = mbedtls_md_hmac_finish( &ctx, T );
+        if ( ret != 0 ) {
+            goto exit;
+        }
+
+        memcpy( okm + where, T, (i != N) ? hash_len : (okm_len - where) );
+        where += hash_len;
+        T_len = hash_len;
+    }
+
+exit:
+    mbedtls_md_free( &ctx );
+
+    return( ret );
+}
+
+#endif /* MBEDTLS_HKDF_C */
diff --git a/library/version_features.c b/library/version_features.c
index 861276a..82b8dd0 100644
--- a/library/version_features.c
+++ b/library/version_features.c
@@ -246,6 +246,9 @@
 #if defined(MBEDTLS_CIPHER_MODE_CBC)
     "MBEDTLS_CIPHER_MODE_CBC",
 #endif /* MBEDTLS_CIPHER_MODE_CBC */
+#if defined(MBEDTLS_CIPHER_MODE_OFB)
+    "MBEDTLS_CIPHER_MODE_OFB",
+#endif /* MBEDTLS_CIPHER_MODE_OFB */
 #if defined(MBEDTLS_CIPHER_MODE_CFB)
     "MBEDTLS_CIPHER_MODE_CFB",
 #endif /* MBEDTLS_CIPHER_MODE_CFB */
@@ -582,6 +585,9 @@
 #if defined(MBEDTLS_HAVEGE_C)
     "MBEDTLS_HAVEGE_C",
 #endif /* MBEDTLS_HAVEGE_C */
+#if defined(MBEDTLS_HKDF_C)
+    "MBEDTLS_HKDF_C",
+#endif /* MBEDTLS_HKDF_C */
 #if defined(MBEDTLS_HMAC_DRBG_C)
     "MBEDTLS_HMAC_DRBG_C",
 #endif /* MBEDTLS_HMAC_DRBG_C */
diff --git a/scripts/generate_errors.pl b/scripts/generate_errors.pl
index ac0fbff..7290b87 100755
--- a/scripts/generate_errors.pl
+++ b/scripts/generate_errors.pl
@@ -31,7 +31,7 @@
 
 my @low_level_modules = qw( AES ARC4 ASN1 BASE64 BIGNUM BLOWFISH
                             CAMELLIA CCM CMAC CTR_DRBG DES
-                            ENTROPY GCM HMAC_DRBG MD2 MD4 MD5
+                            ENTROPY GCM HKDF HMAC_DRBG MD2 MD4 MD5
                             NET OID PADLOCK PBKDF2 RIPEMD160
                             SHA1 SHA256 SHA512 THREADING XTEA );
 my @high_level_modules = qw( CIPHER DHM ECP MD
diff --git a/tests/CMakeLists.txt b/tests/CMakeLists.txt
index 16e19a9..bcd97a0 100644
--- a/tests/CMakeLists.txt
+++ b/tests/CMakeLists.txt
@@ -81,6 +81,7 @@
 add_test_suite(gcm gcm.aes192_de)
 add_test_suite(gcm gcm.aes256_de)
 add_test_suite(gcm gcm.camellia)
+add_test_suite(hkdf)
 add_test_suite(hmac_drbg hmac_drbg.misc)
 add_test_suite(hmac_drbg hmac_drbg.no_reseed)
 add_test_suite(hmac_drbg hmac_drbg.nopr)
diff --git a/tests/Makefile b/tests/Makefile
index edb515c..f34ae19 100644
--- a/tests/Makefile
+++ b/tests/Makefile
@@ -46,7 +46,8 @@
 endif
 
 APPS =	test_suite_aes.ecb$(EXEXT)	test_suite_aes.cbc$(EXEXT)	\
-	test_suite_aes.cfb$(EXEXT)	test_suite_aes.xts$(EXEXT)	\
+	test_suite_aes.cfb$(EXEXT)	test_suite_aes.ofb$(EXEXT)	\
+	test_suite_aes.xts$(EXEXT)	\
 	test_suite_aes.rest$(EXEXT)	\
 	test_suite_arc4$(EXEXT)		test_suite_asn1write$(EXEXT)	\
 	test_suite_base64$(EXEXT)	test_suite_blowfish$(EXEXT)	\
@@ -71,6 +72,7 @@
 	test_suite_gcm.aes192_en$(EXEXT)				\
 	test_suite_gcm.aes256_en$(EXEXT)				\
 	test_suite_gcm.camellia$(EXEXT)					\
+	test_suite_hkdf$(EXEXT)						\
 	test_suite_hmac_drbg.misc$(EXEXT)				\
 	test_suite_hmac_drbg.no_reseed$(EXEXT)				\
 	test_suite_hmac_drbg.nopr$(EXEXT)				\
@@ -110,6 +112,10 @@
 	echo "  Gen   $@"
 	perl scripts/generate_code.pl suites test_suite_aes test_suite_aes.cfb
 
+test_suite_aes.ofb.c : suites/test_suite_aes.function suites/test_suite_aes.ofb.data scripts/generate_code.pl suites/helpers.function suites/main_test.function
+	echo "  Gen   $@"
+	perl scripts/generate_code.pl suites test_suite_aes test_suite_aes.ofb
+
 test_suite_aes.xts.c : suites/test_suite_aes.function suites/test_suite_aes.xts.data scripts/generate_code.pl suites/helpers.function suites/main_test.function
 	echo "  Gen   $@"
 	perl scripts/generate_code.pl suites test_suite_aes test_suite_aes.xts
@@ -182,6 +188,10 @@
 	echo "  Gen   $@"
 	perl scripts/generate_code.pl suites test_suite_gcm test_suite_gcm.camellia
 
+test_suite_hkdf.c : suites/test_suite_hkdf.function suites/test_suite_hkdf.data scripts/generate_code.pl suites/helpers.function suites/main_test.function
+	echo "  Gen   $@"
+	perl scripts/generate_code.pl suites test_suite_hkdf test_suite_hkdf
+
 test_suite_hmac_drbg.misc.c : suites/test_suite_hmac_drbg.function suites/test_suite_hmac_drbg.misc.data scripts/generate_code.pl suites/helpers.function suites/main_test.function
 	echo "  Gen   $@"
 	perl scripts/generate_code.pl suites test_suite_hmac_drbg test_suite_hmac_drbg.misc
@@ -214,6 +224,10 @@
 	echo "  CC    $<"
 	$(CC) $(LOCAL_CFLAGS) $(CFLAGS) $<	$(LOCAL_LDFLAGS) $(LDFLAGS) -o $@
 
+test_suite_aes.ofb$(EXEXT): test_suite_aes.ofb.c $(DEP)
+	echo "  CC    $<"
+	$(CC) $(LOCAL_CFLAGS) $(CFLAGS) $<	$(LOCAL_LDFLAGS) $(LDFLAGS) -o $@
+
 test_suite_aes.xts$(EXEXT): test_suite_aes.xts.c $(DEP)
 	echo "  CC    $<"
 	$(CC) $(LOCAL_CFLAGS) $(CFLAGS) $<	$(LOCAL_LDFLAGS) $(LDFLAGS) -o $@
@@ -350,6 +364,10 @@
 	echo "  CC    $<"
 	$(CC) $(LOCAL_CFLAGS) $(CFLAGS) $<	$(LOCAL_LDFLAGS) $(LDFLAGS) -o $@
 
+test_suite_hkdf$(EXEXT): test_suite_hkdf.c $(DEP)
+	echo "  CC    $<"
+	$(CC) $(LOCAL_CFLAGS) $(CFLAGS) $<	$(LOCAL_LDFLAGS) $(LDFLAGS) -o $@
+
 test_suite_hmac_drbg.misc$(EXEXT): test_suite_hmac_drbg.misc.c $(DEP)
 	echo "  CC    $<"
 	$(CC) $(LOCAL_CFLAGS) $(CFLAGS) $<	$(LOCAL_LDFLAGS) $(LDFLAGS) -o $@
diff --git a/tests/suites/test_suite_aes.function b/tests/suites/test_suite_aes.function
index 6aeffd2..9a98218 100644
--- a/tests/suites/test_suite_aes.function
+++ b/tests/suites/test_suite_aes.function
@@ -303,6 +303,58 @@
 }
 /* END_CASE */
 
+/* BEGIN_CASE depends_on:MBEDTLS_CIPHER_MODE_OFB */
+void aes_encrypt_ofb( int fragment_size, char *hex_key_string,
+                        char *hex_iv_string, char *hex_src_string,
+                        char *hex_dst_string )
+{
+    unsigned char key_str[100];
+    unsigned char iv_str[100];
+    unsigned char src_str[200];
+    unsigned char dst_str[200];
+    unsigned char output[200];
+    mbedtls_aes_context ctx;
+    size_t iv_offset = 0;
+    int in_buffer_len;
+    unsigned char* src_str_next;
+    int key_len;
+
+    memset(key_str, 0x00, 100);
+    memset(iv_str, 0x00, 100);
+    memset(src_str, 0x00, 200);
+    memset(dst_str, 0x00, 200);
+    memset(output, 0x00, 200);
+    mbedtls_aes_init( &ctx );
+
+    key_len = unhexify( key_str, hex_key_string );
+    unhexify( iv_str, hex_iv_string );
+    in_buffer_len = unhexify( src_str, hex_src_string );
+
+    TEST_ASSERT( mbedtls_aes_setkey_enc( &ctx, key_str, key_len * 8 ) == 0 );
+    src_str_next = src_str;
+
+    while( in_buffer_len > 0 )
+    {
+        TEST_ASSERT( mbedtls_aes_crypt_ofb( &ctx, fragment_size, &iv_offset,
+                                            iv_str, src_str_next, output ) == 0 );
+
+        hexify( dst_str, output, fragment_size );
+        TEST_ASSERT( strncmp( (char *) dst_str, hex_dst_string,
+                                ( 2 * fragment_size) ) == 0 );
+
+        in_buffer_len -= fragment_size;
+        hex_dst_string += ( fragment_size * 2 );
+        src_str_next += fragment_size;
+
+        if( in_buffer_len < fragment_size )
+            fragment_size = in_buffer_len;
+    }
+
+exit:
+    mbedtls_aes_free( &ctx );
+}
+/* END_CASE */
+
 /* BEGIN_CASE depends_on:MBEDTLS_CIPHER_MODE_XTS */
 void aes_encrypt_xts( char *hex_key_string, char *hex_data_unit_string,
                       char *hex_src_string, char *hex_dst_string )
diff --git a/tests/suites/test_suite_aes.ofb.data b/tests/suites/test_suite_aes.ofb.data
new file mode 100644
index 0000000..4b9d80e
--- /dev/null
+++ b/tests/suites/test_suite_aes.ofb.data
@@ -0,0 +1,35 @@
+# NIST Special Publication 800-38A
+# Recommendation for Block Cipher Modes of Operation
+# Test Vectors - Appendix F, Section F.4
+OFB-AES128.Encrypt - Single block
+depends_on:MBEDTLS_CIPHER_MODE_OFB
+aes_encrypt_ofb:16:"2b7e151628aed2a6abf7158809cf4f3c":"000102030405060708090a0b0c0d0e0f":"6bc1bee22e409f96e93d7e117393172a":"3b3fd92eb72dad20333449f8e83cfb4a"
+
+OFB-AES128.Encrypt - Partial blocks - 7 bytes
+depends_on:MBEDTLS_CIPHER_MODE_OFB
+aes_encrypt_ofb:5:"2b7e151628aed2a6abf7158809cf4f3c":"000102030405060708090a0b0c0d0e0f":"6bc1bee22e409f96e93d7e117393172aae2d8a571e03ac9c9eb76fac45af8e5130c81c46a35ce411e5fbc1191a0a52eff69f2445df4f9b17ad2b417be66c3710":"3b3fd92eb72dad20333449f8e83cfb4a7789508d16918f03f53c52dac54ed8259740051e9c5fecf64344f7a82260edcc304c6528f659c77866a510d9c1d6ae5e"
+
+OFB-AES128.Encrypt - Test NIST SP800-38A - F.4.1
+depends_on:MBEDTLS_CIPHER_MODE_OFB
+aes_encrypt_ofb:16:"2b7e151628aed2a6abf7158809cf4f3c":"000102030405060708090a0b0c0d0e0f":"6bc1bee22e409f96e93d7e117393172aae2d8a571e03ac9c9eb76fac45af8e5130c81c46a35ce411e5fbc1191a0a52eff69f2445df4f9b17ad2b417be66c3710":"3b3fd92eb72dad20333449f8e83cfb4a7789508d16918f03f53c52dac54ed8259740051e9c5fecf64344f7a82260edcc304c6528f659c77866a510d9c1d6ae5e"
+
+OFB-AES128.Decrypt - Test NIST SP800-38A - F.4.2
+depends_on:MBEDTLS_CIPHER_MODE_OFB
+aes_encrypt_ofb:16:"2b7e151628aed2a6abf7158809cf4f3c":"000102030405060708090a0b0c0d0e0f":"3b3fd92eb72dad20333449f8e83cfb4a7789508d16918f03f53c52dac54ed8259740051e9c5fecf64344f7a82260edcc304c6528f659c77866a510d9c1d6ae5e":"6bc1bee22e409f96e93d7e117393172aae2d8a571e03ac9c9eb76fac45af8e5130c81c46a35ce411e5fbc1191a0a52eff69f2445df4f9b17ad2b417be66c3710"
+
+OFB-AES192.Encrypt - Test NIST SP800-38A - F.4.3
+depends_on:MBEDTLS_CIPHER_MODE_OFB
+aes_encrypt_ofb:16:"8e73b0f7da0e6452c810f32b809079e562f8ead2522c6b7b":"000102030405060708090a0b0c0d0e0f":"6bc1bee22e409f96e93d7e117393172aae2d8a571e03ac9c9eb76fac45af8e5130c81c46a35ce411e5fbc1191a0a52eff69f2445df4f9b17ad2b417be66c3710":"cdc80d6fddf18cab34c25909c99a4174fcc28b8d4c63837c09e81700c11004018d9a9aeac0f6596f559c6d4daf59a5f26d9f200857ca6c3e9cac524bd9acc92a"
+
+OFB-AES192.Decrypt - Test NIST SP800-38A - F.4.4
+depends_on:MBEDTLS_CIPHER_MODE_OFB
+aes_encrypt_ofb:16:"8e73b0f7da0e6452c810f32b809079e562f8ead2522c6b7b":"000102030405060708090a0b0c0d0e0f":"cdc80d6fddf18cab34c25909c99a4174fcc28b8d4c63837c09e81700c11004018d9a9aeac0f6596f559c6d4daf59a5f26d9f200857ca6c3e9cac524bd9acc92a":"6bc1bee22e409f96e93d7e117393172aae2d8a571e03ac9c9eb76fac45af8e5130c81c46a35ce411e5fbc1191a0a52eff69f2445df4f9b17ad2b417be66c3710"
+
+OFB-AES256.Encrypt - Test NIST SP800-38A - F.4.5
+depends_on:MBEDTLS_CIPHER_MODE_OFB
+aes_encrypt_ofb:16:"603deb1015ca71be2b73aef0857d77811f352c073b6108d72d9810a30914dff4":"000102030405060708090a0b0c0d0e0f":"6bc1bee22e409f96e93d7e117393172aae2d8a571e03ac9c9eb76fac45af8e5130c81c46a35ce411e5fbc1191a0a52eff69f2445df4f9b17ad2b417be66c3710":"dc7e84bfda79164b7ecd8486985d38604febdc6740d20b3ac88f6ad82a4fb08d71ab47a086e86eedf39d1c5bba97c4080126141d67f37be8538f5a8be740e484"
+
+OFB-AES256.Decrypt - Test NIST SP800-38A - F.4.6
+depends_on:MBEDTLS_CIPHER_MODE_OFB
+aes_encrypt_ofb:16:"603deb1015ca71be2b73aef0857d77811f352c073b6108d72d9810a30914dff4":"000102030405060708090a0b0c0d0e0f":"dc7e84bfda79164b7ecd8486985d38604febdc6740d20b3ac88f6ad82a4fb08d71ab47a086e86eedf39d1c5bba97c4080126141d67f37be8538f5a8be740e484":"6bc1bee22e409f96e93d7e117393172aae2d8a571e03ac9c9eb76fac45af8e5130c81c46a35ce411e5fbc1191a0a52eff69f2445df4f9b17ad2b417be66c3710"
+
diff --git a/tests/suites/test_suite_cipher.aes.data b/tests/suites/test_suite_cipher.aes.data
index 4742251..f212fa4 100644
--- a/tests/suites/test_suite_cipher.aes.data
+++ b/tests/suites/test_suite_cipher.aes.data
@@ -474,6 +474,110 @@
 depends_on:MBEDTLS_AES_C:MBEDTLS_CIPHER_MODE_CFB
 enc_dec_buf_multipart:MBEDTLS_CIPHER_AES_128_CFB128:128:16:16:-1:16:16:16:16
 
+AES-128 OFB - Encrypt and decrypt 0 bytes
+depends_on:MBEDTLS_AES_C:MBEDTLS_CIPHER_MODE_OFB
+enc_dec_buf:MBEDTLS_CIPHER_AES_128_OFB:"AES-128-OFB":128:0:-1
+
+AES-128 OFB - Encrypt and decrypt 1 byte
+depends_on:MBEDTLS_AES_C:MBEDTLS_CIPHER_MODE_OFB
+enc_dec_buf:MBEDTLS_CIPHER_AES_128_OFB:"AES-128-OFB":128:1:-1
+
+AES-128 OFB - Encrypt and decrypt 2 bytes
+depends_on:MBEDTLS_AES_C:MBEDTLS_CIPHER_MODE_OFB
+enc_dec_buf:MBEDTLS_CIPHER_AES_128_OFB:"AES-128-OFB":128:2:-1
+
+AES-128 OFB - Encrypt and decrypt 7 bytes
+depends_on:MBEDTLS_AES_C:MBEDTLS_CIPHER_MODE_OFB
+enc_dec_buf:MBEDTLS_CIPHER_AES_128_OFB:"AES-128-OFB":128:7:-1
+
+AES-128 OFB - Encrypt and decrypt 8 bytes
+depends_on:MBEDTLS_AES_C:MBEDTLS_CIPHER_MODE_OFB
+enc_dec_buf:MBEDTLS_CIPHER_AES_128_OFB:"AES-128-OFB":128:8:-1
+
+AES-128 OFB - Encrypt and decrypt 9 bytes
+depends_on:MBEDTLS_AES_C:MBEDTLS_CIPHER_MODE_OFB
+enc_dec_buf:MBEDTLS_CIPHER_AES_128_OFB:"AES-128-OFB":128:9:-1
+
+AES-128 OFB - Encrypt and decrypt 15 bytes
+depends_on:MBEDTLS_AES_C:MBEDTLS_CIPHER_MODE_OFB
+enc_dec_buf:MBEDTLS_CIPHER_AES_128_OFB:"AES-128-OFB":128:15:-1
+
+AES-128 OFB - Encrypt and decrypt 16 bytes
+depends_on:MBEDTLS_AES_C:MBEDTLS_CIPHER_MODE_OFB
+enc_dec_buf:MBEDTLS_CIPHER_AES_128_OFB:"AES-128-OFB":128:16:-1
+
+AES-128 OFB - Encrypt and decrypt 17 bytes
+depends_on:MBEDTLS_AES_C:MBEDTLS_CIPHER_MODE_OFB
+enc_dec_buf:MBEDTLS_CIPHER_AES_128_OFB:"AES-128-OFB":128:17:-1
+
+AES-128 OFB - Encrypt and decrypt 31 bytes
+depends_on:MBEDTLS_AES_C:MBEDTLS_CIPHER_MODE_OFB
+enc_dec_buf:MBEDTLS_CIPHER_AES_128_OFB:"AES-128-OFB":128:31:-1
+
+AES-128 OFB - Encrypt and decrypt 32 bytes
+depends_on:MBEDTLS_AES_C:MBEDTLS_CIPHER_MODE_OFB
+enc_dec_buf:MBEDTLS_CIPHER_AES_128_OFB:"AES-128-OFB":128:32:-1
+
+AES-128 OFB - Encrypt and decrypt 32 bytes
+depends_on:MBEDTLS_AES_C:MBEDTLS_CIPHER_MODE_OFB
+enc_dec_buf:MBEDTLS_CIPHER_AES_128_OFB:"AES-128-OFB":128:33:-1
+
+AES-128 OFB - Encrypt and decrypt 47 bytes
+depends_on:MBEDTLS_AES_C:MBEDTLS_CIPHER_MODE_OFB
+enc_dec_buf:MBEDTLS_CIPHER_AES_128_OFB:"AES-128-OFB":128:47:-1
+
+AES-128 OFB - Encrypt and decrypt 48 bytes
+depends_on:MBEDTLS_AES_C:MBEDTLS_CIPHER_MODE_OFB
+enc_dec_buf:MBEDTLS_CIPHER_AES_128_OFB:"AES-128-OFB":128:48:-1
+
+AES-128 OFB - Encrypt and decrypt 49 bytes
+depends_on:MBEDTLS_AES_C:MBEDTLS_CIPHER_MODE_OFB
+enc_dec_buf:MBEDTLS_CIPHER_AES_128_OFB:"AES-128-OFB":128:49:-1
+
+AES-128 OFB - Encrypt and decrypt 0 bytes in multiple parts
+depends_on:MBEDTLS_AES_C:MBEDTLS_CIPHER_MODE_OFB
+enc_dec_buf_multipart:MBEDTLS_CIPHER_AES_128_OFB:128:0:0:-1:0:0:0:0
+
+AES-128 OFB - Encrypt and decrypt 1 bytes in multiple parts 1
+depends_on:MBEDTLS_AES_C:MBEDTLS_CIPHER_MODE_OFB
+enc_dec_buf_multipart:MBEDTLS_CIPHER_AES_128_OFB:128:1:0:-1:1:0:1:0
+
+AES-128 OFB - Encrypt and decrypt 1 bytes in multiple parts 2
+depends_on:MBEDTLS_AES_C:MBEDTLS_CIPHER_MODE_OFB
+enc_dec_buf_multipart:MBEDTLS_CIPHER_AES_128_OFB:128:0:1:-1:0:1:0:1
+
+AES-128 OFB - Encrypt and decrypt 16 bytes in multiple parts 1
+depends_on:MBEDTLS_AES_C:MBEDTLS_CIPHER_MODE_OFB
+enc_dec_buf_multipart:MBEDTLS_CIPHER_AES_128_OFB:128:16:0:-1:16:0:16:0
+
+AES-128 OFB - Encrypt and decrypt 16 bytes in multiple parts 2
+depends_on:MBEDTLS_AES_C:MBEDTLS_CIPHER_MODE_OFB
+enc_dec_buf_multipart:MBEDTLS_CIPHER_AES_128_OFB:128:0:16:-1:0:16:0:16
+
+AES-128 OFB - Encrypt and decrypt 16 bytes in multiple parts 3
+depends_on:MBEDTLS_AES_C:MBEDTLS_CIPHER_MODE_OFB
+enc_dec_buf_multipart:MBEDTLS_CIPHER_AES_128_OFB:128:1:15:-1:1:15:1:15
+
+AES-128 OFB - Encrypt and decrypt 16 bytes in multiple parts 4
+depends_on:MBEDTLS_AES_C:MBEDTLS_CIPHER_MODE_OFB
+enc_dec_buf_multipart:MBEDTLS_CIPHER_AES_128_OFB:128:15:1:-1:15:1:15:1
+
+AES-128 OFB - Encrypt and decrypt 22 bytes in multiple parts 1
+depends_on:MBEDTLS_AES_C:MBEDTLS_CIPHER_MODE_OFB
+enc_dec_buf_multipart:MBEDTLS_CIPHER_AES_128_OFB:128:15:7:-1:15:7:15:7
+
+AES-128 OFB - Encrypt and decrypt 22 bytes in multiple parts 2
+depends_on:MBEDTLS_AES_C:MBEDTLS_CIPHER_MODE_OFB
+enc_dec_buf_multipart:MBEDTLS_CIPHER_AES_128_OFB:128:16:6:-1:16:6:16:6
+
+AES-128 OFB - Encrypt and decrypt 23 bytes in multiple parts 1
+depends_on:MBEDTLS_AES_C:MBEDTLS_CIPHER_MODE_OFB
+enc_dec_buf_multipart:MBEDTLS_CIPHER_AES_128_OFB:128:17:6:-1:17:6:17:6
+
+AES-128 OFB - Encrypt and decrypt 32 bytes in multiple parts 1
+depends_on:MBEDTLS_AES_C:MBEDTLS_CIPHER_MODE_OFB
+enc_dec_buf_multipart:MBEDTLS_CIPHER_AES_128_OFB:128:16:16:-1:16:16:16:16
+
 AES-128 XTS - Encrypt and decrypt 16 bytes
 depends_on:MBEDTLS_AES_C:MBEDTLS_CIPHER_MODE_XTS
 enc_dec_buf:MBEDTLS_CIPHER_AES_128_XTS:"AES-128-XTS":256:16:-1
diff --git a/tests/suites/test_suite_hkdf.data b/tests/suites/test_suite_hkdf.data
new file mode 100644
index 0000000..b58ec93
--- /dev/null
+++ b/tests/suites/test_suite_hkdf.data
@@ -0,0 +1,27 @@
+HKDF RFC5869 Test Vector #1
+depends_on:MBEDTLS_SHA256_C
+test_hkdf:6:"0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b":"000102030405060708090a0b0c":"f0f1f2f3f4f5f6f7f8f9":"3cb25f25faacd57a90434f64d0362f2a2d2d0a90cf1a5a4c5db02d56ecc4c5bf34007208d5b887185865"
+
+HKDF RFC5869 Test Vector #2
+depends_on:MBEDTLS_SHA256_C
+test_hkdf:6:"000102030405060708090a0b0c0d0e0f101112131415161718191a1b1c1d1e1f202122232425262728292a2b2c2d2e2f303132333435363738393a3b3c3d3e3f404142434445464748494a4b4c4d4e4f":"606162636465666768696a6b6c6d6e6f707172737475767778797a7b7c7d7e7f808182838485868788898a8b8c8d8e8f909192939495969798999a9b9c9d9e9fa0a1a2a3a4a5a6a7a8a9aaabacadaeaf":"b0b1b2b3b4b5b6b7b8b9babbbcbdbebfc0c1c2c3c4c5c6c7c8c9cacbcccdcecfd0d1d2d3d4d5d6d7d8d9dadbdcdddedfe0e1e2e3e4e5e6e7e8e9eaebecedeeeff0f1f2f3f4f5f6f7f8f9fafbfcfdfeff":"b11e398dc80327a1c8e7f78c596a49344f012eda2d4efad8a050cc4c19afa97c59045a99cac7827271cb41c65e590e09da3275600c2f09b8367793a9aca3db71cc30c58179ec3e87c14c01d5c1f3434f1d87"
+
+HKDF RFC5869 Test Vector #3
+depends_on:MBEDTLS_SHA256_C
+test_hkdf:6:"0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b":"":"":"8da4e775a563c18f715f802a063c5a31b8a11f5c5ee1879ec3454e5f3c738d2d9d201395faa4b61a96c8"
+
+HKDF RFC5869 Test Vector #4
+depends_on:MBEDTLS_SHA1_C
+test_hkdf:4:"0b0b0b0b0b0b0b0b0b0b0b":"000102030405060708090a0b0c":"f0f1f2f3f4f5f6f7f8f9":"085a01ea1b10f36933068b56efa5ad81a4f14b822f5b091568a9cdd4f155fda2c22e422478d305f3f896"
+
+HKDF RFC5869 Test Vector #5
+depends_on:MBEDTLS_SHA1_C
+test_hkdf:4:"000102030405060708090a0b0c0d0e0f101112131415161718191a1b1c1d1e1f202122232425262728292a2b2c2d2e2f303132333435363738393a3b3c3d3e3f404142434445464748494a4b4c4d4e4f":"606162636465666768696a6b6c6d6e6f707172737475767778797a7b7c7d7e7f808182838485868788898a8b8c8d8e8f909192939495969798999a9b9c9d9e9fa0a1a2a3a4a5a6a7a8a9aaabacadaeaf":"b0b1b2b3b4b5b6b7b8b9babbbcbdbebfc0c1c2c3c4c5c6c7c8c9cacbcccdcecfd0d1d2d3d4d5d6d7d8d9dadbdcdddedfe0e1e2e3e4e5e6e7e8e9eaebecedeeeff0f1f2f3f4f5f6f7f8f9fafbfcfdfeff":"0bd770a74d1160f7c9f12cd5912a06ebff6adcae899d92191fe4305673ba2ffe8fa3f1a4e5ad79f3f334b3b202b2173c486ea37ce3d397ed034c7f9dfeb15c5e927336d0441f4c4300e2cff0d0900b52d3b4"
+
+HKDF RFC5869 Test Vector #6
+depends_on:MBEDTLS_SHA1_C
+test_hkdf:4:"0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b":"":"":"0ac1af7002b3d761d1e55298da9d0506b9ae52057220a306e07b6b87e8df21d0ea00033de03984d34918"
+
+HKDF RFC5869 Test Vector #7
+depends_on:MBEDTLS_SHA1_C
+test_hkdf:4:"0c0c0c0c0c0c0c0c0c0c0c0c0c0c0c0c0c0c0c0c0c0c":"":"":"2c91117204d745f3500d636a62f64f0ab3bae548aa53d423b0d1f27ebba6f5e5673a081d70cce7acfc48"
diff --git a/tests/suites/test_suite_hkdf.function b/tests/suites/test_suite_hkdf.function
new file mode 100644
index 0000000..21a9447
--- /dev/null
+++ b/tests/suites/test_suite_hkdf.function
@@ -0,0 +1,39 @@
+/* BEGIN_HEADER */
+#include "mbedtls/hkdf.h"
+/* END_HEADER */
+
+/* BEGIN_DEPENDENCIES
+ * depends_on:MBEDTLS_HKDF_C
+ * END_DEPENDENCIES
+ */
+
+/* BEGIN_CASE */
+void test_hkdf(int md_alg, char *hex_ikm_string, char *hex_salt_string,
+               char *hex_info_string, char *hex_okm_string)
+{
+    int ret;
+    size_t ikm_len, salt_len, info_len, okm_len;
+    unsigned char ikm[1024] = {'\0'};
+    unsigned char salt[1024] = {'\0'};
+    unsigned char info[1024] = {'\0'};
+    unsigned char expected_okm[1024] = {'\0'};
+    unsigned char okm[1024] = {'\0'};
+    unsigned char okm_string[1000] = {'\0'};
+
+    const mbedtls_md_info_t *md = mbedtls_md_info_from_type(md_alg);
+    TEST_ASSERT(md != NULL);
+
+    ikm_len = unhexify(ikm, hex_ikm_string);
+    salt_len = unhexify(salt, hex_salt_string);
+    info_len = unhexify(info, hex_info_string);
+    okm_len = unhexify(expected_okm, hex_okm_string);
+
+    ret = mbedtls_hkdf(md, salt, salt_len, ikm, ikm_len, info, info_len, okm,
+                       okm_len);
+    TEST_ASSERT(ret == 0);
+
+    // Run hexify on it so that it looks nicer if the assertion fails
+    hexify(okm_string, okm, okm_len);
+    TEST_ASSERT(!strcmp((char *)okm_string, hex_okm_string));
+}
+/* END_CASE */
diff --git a/visualc/VS2010/mbedTLS.vcxproj b/visualc/VS2010/mbedTLS.vcxproj
index 802cce7..4c5c480 100644
--- a/visualc/VS2010/mbedTLS.vcxproj
+++ b/visualc/VS2010/mbedTLS.vcxproj
@@ -178,6 +178,7 @@
     <ClInclude Include="..\..\include\mbedtls\error.h" />
     <ClInclude Include="..\..\include\mbedtls\gcm.h" />
     <ClInclude Include="..\..\include\mbedtls\havege.h" />
+    <ClInclude Include="..\..\include\mbedtls\hkdf.h" />
     <ClInclude Include="..\..\include\mbedtls\hmac_drbg.h" />
     <ClInclude Include="..\..\include\mbedtls\md.h" />
     <ClInclude Include="..\..\include\mbedtls\md2.h" />
@@ -248,6 +249,7 @@
     <ClCompile Include="..\..\library\error.c" />
     <ClCompile Include="..\..\library\gcm.c" />
     <ClCompile Include="..\..\library\havege.c" />
+    <ClCompile Include="..\..\library\hkdf.c" />
     <ClCompile Include="..\..\library\hmac_drbg.c" />
     <ClCompile Include="..\..\library\md.c" />
     <ClCompile Include="..\..\library\md2.c" />