diff --git a/include/polarssl/dhm.h b/include/polarssl/dhm.h
new file mode 100644
index 0000000..127d626
--- /dev/null
+++ b/include/polarssl/dhm.h
@@ -0,0 +1,122 @@
+/**
+ * \file dhm.h
+ */
+#ifndef XYSSL_DHM_H
+#define XYSSL_DHM_H
+
+#include "xyssl/bignum.h"
+
+#define XYSSL_ERR_DHM_BAD_INPUT_DATA                    -0x0480
+#define XYSSL_ERR_DHM_READ_PARAMS_FAILED                -0x0490
+#define XYSSL_ERR_DHM_MAKE_PARAMS_FAILED                -0x04A0
+#define XYSSL_ERR_DHM_READ_PUBLIC_FAILED                -0x04B0
+#define XYSSL_ERR_DHM_MAKE_PUBLIC_FAILED                -0x04C0
+#define XYSSL_ERR_DHM_CALC_SECRET_FAILED                -0x04D0
+
+typedef struct
+{
+    int len;    /*!<  size(P) in chars  */
+    mpi P;      /*!<  prime modulus     */
+    mpi G;      /*!<  generator         */
+    mpi X;      /*!<  secret value      */
+    mpi GX;     /*!<  self = G^X mod P  */
+    mpi GY;     /*!<  peer = G^Y mod P  */
+    mpi K;      /*!<  key = GY^X mod P  */
+    mpi RP;     /*!<  cached R^2 mod P  */
+}
+dhm_context;
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/**
+ * \brief          Parse the ServerKeyExchange parameters
+ *
+ * \param ctx      DHM context
+ * \param p        &(start of input buffer)
+ * \param end      end of buffer
+ *
+ * \return         0 if successful, or an XYSSL_ERR_DHM_XXX error code
+ */
+int dhm_read_params( dhm_context *ctx,
+                     unsigned char **p,
+                     unsigned char *end );
+
+/**
+ * \brief          Setup and write the ServerKeyExchange parameters
+ *
+ * \param ctx      DHM context
+ * \param x_size   private value size in bits
+ * \param output   destination buffer
+ * \param olen     number of chars written
+ * \param f_rng    RNG function
+ * \param p_rng    RNG parameter
+ *
+ * \note           This function assumes that ctx->P and ctx->G
+ *                 have already been properly set (for example
+ *                 using mpi_read_string or mpi_read_binary).
+ *
+ * \return         0 if successful, or an XYSSL_ERR_DHM_XXX error code
+ */
+int dhm_make_params( dhm_context *ctx, int s_size,
+                     unsigned char *output, int *olen,
+                     int (*f_rng)(void *), void *p_rng );
+
+/**
+ * \brief          Import the peer's public value G^Y
+ *
+ * \param ctx      DHM context
+ * \param input    input buffer
+ * \param ilen     size of buffer
+ *
+ * \return         0 if successful, or an XYSSL_ERR_DHM_XXX error code
+ */
+int dhm_read_public( dhm_context *ctx,
+                     unsigned char *input, int ilen );
+
+/**
+ * \brief          Create own private value X and export G^X
+ *
+ * \param ctx      DHM context
+ * \param x_size   private value size in bits
+ * \param output   destination buffer
+ * \param olen     must be equal to ctx->P.len
+ * \param f_rng    RNG function
+ * \param p_rng    RNG parameter
+ *
+ * \return         0 if successful, or an XYSSL_ERR_DHM_XXX error code
+ */
+int dhm_make_public( dhm_context *ctx, int s_size,
+                     unsigned char *output, int olen,
+                     int (*f_rng)(void *), void *p_rng );
+
+/**
+ * \brief          Derive and export the shared secret (G^Y)^X mod P
+ *
+ * \param ctx      DHM context
+ * \param output   destination buffer
+ * \param olen     number of chars written
+ *
+ * \return         0 if successful, or an XYSSL_ERR_DHM_XXX error code
+ */
+int dhm_calc_secret( dhm_context *ctx,
+                     unsigned char *output, int *olen );
+
+/*
+ * \brief          Free the components of a DHM key
+ */
+void dhm_free( dhm_context *ctx );
+
+/**
+ * \brief          Checkup routine
+ *
+ * \return         0 if successful, or 1 if the test failed
+ */
+int dhm_self_test( int verbose );
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif