diff --git a/include/polarssl/md.h b/include/polarssl/md.h
index 88596cb041..b81ebf1beb 100644
--- a/include/polarssl/md.h
+++ b/include/polarssl/md.h
@@ -111,6 +111,8 @@ typedef struct {
     /** Free the given context */
     void (*ctx_free_func)( void *ctx );
 
+    /** Internal use only */
+    void (*process_func)( void *ctx, const unsigned char *input );
 } md_info_t;
 
 /**
@@ -347,6 +349,9 @@ int md_hmac( const md_info_t *md_info, const unsigned char *key, size_t keylen,
                 const unsigned char *input, size_t ilen,
                 unsigned char *output );
 
+/* Internal use */
+int md_process( md_context_t *ctx, const unsigned char *data );
+
 #ifdef __cplusplus
 }
 #endif
diff --git a/include/polarssl/md2.h b/include/polarssl/md2.h
index 1f60470fdc..02a0a10e9a 100644
--- a/include/polarssl/md2.h
+++ b/include/polarssl/md2.h
@@ -146,6 +146,9 @@ void md2_hmac( const unsigned char *key, size_t keylen,
  */
 int md2_self_test( int verbose );
 
+/* Internal use */
+void md2_process( md2_context *ctx );
+
 #ifdef __cplusplus
 }
 #endif
diff --git a/include/polarssl/md4.h b/include/polarssl/md4.h
index 641edf1892..4791fb1bc2 100644
--- a/include/polarssl/md4.h
+++ b/include/polarssl/md4.h
@@ -152,6 +152,9 @@ void md4_hmac( const unsigned char *key, size_t keylen,
  */
 int md4_self_test( int verbose );
 
+/* Internal use */
+void md4_process( md4_context *ctx, const unsigned char data[64] );
+
 #ifdef __cplusplus
 }
 #endif
diff --git a/include/polarssl/sha4.h b/include/polarssl/sha4.h
index 6aae124465..5563676e38 100644
--- a/include/polarssl/sha4.h
+++ b/include/polarssl/sha4.h
@@ -161,6 +161,9 @@ void sha4_hmac( const unsigned char *key, size_t keylen,
  */
 int sha4_self_test( int verbose );
 
+/* Internal use */
+void sha4_process( sha4_context *ctx, const unsigned char data[128] );
+
 #ifdef __cplusplus
 }
 #endif
diff --git a/library/md.c b/library/md.c
index 96065c95f0..07a93ec55b 100644
--- a/library/md.c
+++ b/library/md.c
@@ -294,4 +294,14 @@ int md_hmac( const md_info_t *md_info, const unsigned char *key, size_t keylen,
     return 0;
 }
 
+int md_process( md_context_t *ctx, const unsigned char *data )
+{
+    if( ctx == NULL || ctx->md_info == NULL )
+        return POLARSSL_ERR_MD_BAD_INPUT_DATA;
+
+    ctx->md_info->process_func( ctx->md_ctx, data );
+
+    return 0;
+}
+
 #endif
diff --git a/library/md2.c b/library/md2.c
index 954aa07be8..73abdfa49a 100644
--- a/library/md2.c
+++ b/library/md2.c
@@ -80,7 +80,7 @@ void md2_starts( md2_context *ctx )
     ctx->left = 0;
 }
 
-static void md2_process( md2_context *ctx )
+void md2_process( md2_context *ctx )
 {
     int i, j;
     unsigned char t = 0;
diff --git a/library/md4.c b/library/md4.c
index 82adcd8d36..60125266d2 100644
--- a/library/md4.c
+++ b/library/md4.c
@@ -76,7 +76,7 @@ void md4_starts( md4_context *ctx )
     ctx->state[3] = 0x10325476;
 }
 
-static void md4_process( md4_context *ctx, const unsigned char data[64] )
+void md4_process( md4_context *ctx, const unsigned char data[64] )
 {
     uint32_t X[16], A, B, C, D;
 
diff --git a/library/md_wrap.c b/library/md_wrap.c
index f276db5925..93c35f39cd 100644
--- a/library/md_wrap.c
+++ b/library/md_wrap.c
@@ -117,6 +117,13 @@ static void md2_ctx_free( void *ctx )
     free( ctx );
 }
 
+static void md2_process_wrap( void *ctx, const unsigned char *data )
+{
+    ((void) data);
+
+    md2_process( (md2_context *) ctx );
+}
+
 const md_info_t md2_info = {
     POLARSSL_MD_MD2,
     "MD2",
@@ -133,6 +140,7 @@ const md_info_t md2_info = {
     md2_hmac,
     md2_ctx_alloc,
     md2_ctx_free,
+    md2_process_wrap,
 };
 
 #endif
@@ -195,6 +203,11 @@ void md4_ctx_free( void *ctx )
     free( ctx );
 }
 
+void md4_process_wrap( void *ctx, const unsigned char *data )
+{
+    md4_process( (md4_context *) ctx, data );
+}
+
 const md_info_t md4_info = {
     POLARSSL_MD_MD4,
     "MD4",
@@ -211,6 +224,7 @@ const md_info_t md4_info = {
     md4_hmac,
     md4_ctx_alloc,
     md4_ctx_free,
+    md4_process_wrap,
 };
 
 #endif
@@ -273,6 +287,11 @@ static void md5_ctx_free( void *ctx )
     free( ctx );
 }
 
+static void md5_process_wrap( void *ctx, const unsigned char *data )
+{
+    md5_process( (md5_context *) ctx, data );
+}
+
 const md_info_t md5_info = {
     POLARSSL_MD_MD5,
     "MD5",
@@ -289,6 +308,7 @@ const md_info_t md5_info = {
     md5_hmac,
     md5_ctx_alloc,
     md5_ctx_free,
+    md5_process_wrap,
 };
 
 #endif
@@ -351,6 +371,11 @@ void sha1_ctx_free( void *ctx )
     free( ctx );
 }
 
+void sha1_process_wrap( void *ctx, const unsigned char *data )
+{
+    sha1_process( (sha1_context *) ctx, data );
+}
+
 const md_info_t sha1_info = {
     POLARSSL_MD_SHA1,
     "SHA1",
@@ -367,6 +392,7 @@ const md_info_t sha1_info = {
     sha1_hmac,
     sha1_ctx_alloc,
     sha1_ctx_free,
+    sha1_process_wrap,
 };
 
 #endif
@@ -445,6 +471,11 @@ void sha224_ctx_free( void *ctx )
     free( ctx );
 }
 
+void sha224_process_wrap( void *ctx, const unsigned char *data )
+{
+    sha2_process( (sha2_context *) ctx, data );
+}
+
 const md_info_t sha224_info = {
     POLARSSL_MD_SHA224,
     "SHA224",
@@ -461,6 +492,7 @@ const md_info_t sha224_info = {
     sha224_hmac_wrap,
     sha224_ctx_alloc,
     sha224_ctx_free,
+    sha224_process_wrap,
 };
 
 void sha256_starts_wrap( void *ctx )
@@ -532,6 +564,11 @@ void sha256_ctx_free( void *ctx )
     free( ctx );
 }
 
+void sha256_process_wrap( void *ctx, const unsigned char *data )
+{
+    sha2_process( (sha2_context *) ctx, data );
+}
+
 const md_info_t sha256_info = {
     POLARSSL_MD_SHA256,
     "SHA256",
@@ -548,6 +585,7 @@ const md_info_t sha256_info = {
     sha256_hmac_wrap,
     sha256_ctx_alloc,
     sha256_ctx_free,
+    sha256_process_wrap,
 };
 
 #endif
@@ -623,6 +661,11 @@ void sha384_ctx_free( void *ctx )
     free( ctx );
 }
 
+void sha384_process_wrap( void *ctx, const unsigned char *data )
+{
+    sha4_process( (sha4_context *) ctx, data );
+}
+
 const md_info_t sha384_info = {
     POLARSSL_MD_SHA384,
     "SHA384",
@@ -639,6 +682,7 @@ const md_info_t sha384_info = {
     sha384_hmac_wrap,
     sha384_ctx_alloc,
     sha384_ctx_free,
+    sha384_process_wrap,
 };
 
 void sha512_starts_wrap( void *ctx )
@@ -710,6 +754,11 @@ void sha512_ctx_free( void *ctx )
     free( ctx );
 }
 
+void sha512_process_wrap( void *ctx, const unsigned char *data )
+{
+    sha4_process( (sha4_context *) ctx, data );
+}
+
 const md_info_t sha512_info = {
     POLARSSL_MD_SHA512,
     "SHA512",
@@ -726,6 +775,7 @@ const md_info_t sha512_info = {
     sha512_hmac_wrap,
     sha512_ctx_alloc,
     sha512_ctx_free,
+    sha512_process_wrap,
 };
 
 #endif
diff --git a/library/sha4.c b/library/sha4.c
index 6361a542c2..556cc4fd90 100644
--- a/library/sha4.c
+++ b/library/sha4.c
@@ -152,7 +152,7 @@ void sha4_starts( sha4_context *ctx, int is384 )
     ctx->is384 = is384;
 }
 
-static void sha4_process( sha4_context *ctx, const unsigned char data[128] )
+void sha4_process( sha4_context *ctx, const unsigned char data[128] )
 {
     int i;
     uint64_t temp1, temp2, W[80];