diff --git a/ports/stm32/Makefile b/ports/stm32/Makefile
index 6a44ff30b3..1216cd13bd 100644
--- a/ports/stm32/Makefile
+++ b/ports/stm32/Makefile
@@ -396,6 +396,11 @@ SRC_MOD += $(addprefix $(CC3000_DIR)/src/,\
 	)
 endif
 
+ifeq ($(MICROPY_SSL_MBEDTLS),1)
+CFLAGS_MOD += -DMBEDTLS_CONFIG_FILE='"mbedtls/mbedtls_config.h"'
+SRC_MOD += mbedtls/mbedtls_port.c
+endif
+
 OBJ =
 OBJ += $(PY_O)
 OBJ += $(addprefix $(BUILD)/, $(SRC_LIB:.c=.o))
diff --git a/ports/stm32/mbedtls/mbedtls_config.h b/ports/stm32/mbedtls/mbedtls_config.h
new file mode 100644
index 0000000000..4820140766
--- /dev/null
+++ b/ports/stm32/mbedtls/mbedtls_config.h
@@ -0,0 +1,93 @@
+/*
+ * This file is part of the MicroPython project, http://micropython.org/
+ *
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2018-2019 Damien P. George
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+#ifndef MICROPY_INCLUDED_MBEDTLS_CONFIG_H
+#define MICROPY_INCLUDED_MBEDTLS_CONFIG_H
+
+// Set mbedtls configuration
+#define MBEDTLS_PLATFORM_MEMORY
+#define MBEDTLS_PLATFORM_NO_STD_FUNCTIONS
+#define MBEDTLS_DEPRECATED_REMOVED
+#define MBEDTLS_ENTROPY_HARDWARE_ALT
+#define MBEDTLS_AES_ROM_TABLES
+#define MBEDTLS_CIPHER_MODE_CBC
+#define MBEDTLS_ECP_DP_SECP192R1_ENABLED
+#define MBEDTLS_ECP_DP_SECP224R1_ENABLED
+#define MBEDTLS_ECP_DP_SECP256R1_ENABLED
+#define MBEDTLS_ECP_DP_SECP384R1_ENABLED
+#define MBEDTLS_ECP_DP_SECP521R1_ENABLED
+#define MBEDTLS_ECP_DP_SECP192K1_ENABLED
+#define MBEDTLS_ECP_DP_SECP224K1_ENABLED
+#define MBEDTLS_ECP_DP_SECP256K1_ENABLED
+#define MBEDTLS_ECP_DP_BP256R1_ENABLED
+#define MBEDTLS_ECP_DP_BP384R1_ENABLED
+#define MBEDTLS_ECP_DP_BP512R1_ENABLED
+#define MBEDTLS_ECP_DP_CURVE25519_ENABLED
+#define MBEDTLS_KEY_EXCHANGE_RSA_ENABLED
+#define MBEDTLS_NO_PLATFORM_ENTROPY
+#define MBEDTLS_PKCS1_V15
+#define MBEDTLS_SHA256_SMALLER
+#define MBEDTLS_SSL_PROTO_TLS1
+#define MBEDTLS_SSL_PROTO_TLS1_1
+#define MBEDTLS_SSL_PROTO_TLS1_2
+#define MBEDTLS_SSL_SERVER_NAME_INDICATION
+
+// Enable mbedtls modules
+#define MBEDTLS_AES_C
+#define MBEDTLS_ASN1_PARSE_C
+#define MBEDTLS_BIGNUM_C
+#define MBEDTLS_CIPHER_C
+#define MBEDTLS_CTR_DRBG_C
+//#define MBEDTLS_ECP_C
+#define MBEDTLS_ENTROPY_C
+#define MBEDTLS_MD_C
+#define MBEDTLS_MD5_C
+#define MBEDTLS_OID_C
+#define MBEDTLS_PKCS5_C
+#define MBEDTLS_PK_C
+#define MBEDTLS_PK_PARSE_C
+#define MBEDTLS_PLATFORM_C
+#define MBEDTLS_RSA_C
+#define MBEDTLS_SHA1_C
+#define MBEDTLS_SHA256_C
+#define MBEDTLS_SHA512_C
+#define MBEDTLS_SSL_CLI_C
+#define MBEDTLS_SSL_SRV_C
+#define MBEDTLS_SSL_TLS_C
+#define MBEDTLS_X509_CRT_PARSE_C
+#define MBEDTLS_X509_USE_C
+
+// Memory allocation hooks
+#include <stdlib.h>
+#include <stdio.h>
+void *m_calloc_mbedtls(size_t nmemb, size_t size);
+void m_free_mbedtls(void *ptr);
+#define MBEDTLS_PLATFORM_STD_CALLOC m_calloc_mbedtls
+#define MBEDTLS_PLATFORM_STD_FREE m_free_mbedtls
+#define MBEDTLS_PLATFORM_SNPRINTF_MACRO snprintf
+
+#include "mbedtls/check_config.h"
+
+#endif /* MICROPY_INCLUDED_MBEDTLS_CONFIG_H */
diff --git a/ports/stm32/mbedtls/mbedtls_port.c b/ports/stm32/mbedtls/mbedtls_port.c
new file mode 100644
index 0000000000..efb8d2c2a4
--- /dev/null
+++ b/ports/stm32/mbedtls/mbedtls_port.c
@@ -0,0 +1,96 @@
+/*
+ * This file is part of the MicroPython project, http://micropython.org/
+ *
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2019 Damien P. George
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+#include "py/runtime.h"
+#include "py/gc.h"
+#include "rng.h"
+#include "mbedtls_config.h"
+
+#define DEBUG (0)
+
+#if DEBUG
+static size_t count_links(uint32_t *nb) {
+    void **p = MP_STATE_PORT(mbedtls_memory);
+    size_t n = 0;
+    *nb = 0;
+    while (p != NULL) {
+        ++n;
+        *nb += gc_nbytes(p);
+        p = (void**)p[1];
+    }
+    return n;
+}
+#endif
+
+void *m_calloc_mbedtls(size_t nmemb, size_t size) {
+    void **ptr = m_malloc0(nmemb * size + 2 * sizeof(uintptr_t));
+    #if DEBUG
+    uint32_t nb;
+    size_t n = count_links(&nb);
+    printf("mbed_alloc(%u, %u) -> (%u;%u) %p\n", nmemb, size, n, (uint)nb, ptr);
+    #endif
+    if (MP_STATE_PORT(mbedtls_memory) != NULL) {
+        MP_STATE_PORT(mbedtls_memory)[0] = ptr;
+    }
+    ptr[0] = NULL;
+    ptr[1] = MP_STATE_PORT(mbedtls_memory);
+    MP_STATE_PORT(mbedtls_memory) = ptr;
+    return &ptr[2];
+}
+
+void m_free_mbedtls(void *ptr_in) {
+    void **ptr = &((void**)ptr_in)[-2];
+    #if DEBUG
+    uint32_t nb;
+    size_t n = count_links(&nb);
+    printf("mbed_free(%p, [%p, %p], nbytes=%u, links=%u;%u)\n", ptr, ptr[0], ptr[1], gc_nbytes(ptr), n, (uint)nb);
+    #endif
+    if (ptr[1] != NULL) {
+        ((void**)ptr[1])[0] = ptr[0];
+    }
+    if (ptr[0] != NULL) {
+        ((void**)ptr[0])[1] = ptr[1];
+    } else {
+        MP_STATE_PORT(mbedtls_memory) = ptr[1];
+    }
+    m_free(ptr);
+}
+
+int mbedtls_hardware_poll(void *data, unsigned char *output, size_t len, size_t *olen) {
+    uint32_t val;
+    int n = 0;
+    *olen = len;
+    while (len--) {
+        if (!n) {
+            val = rng_get();
+            n = 4;
+        }
+        *output++ = val;
+        val >>= 8;
+        --n;
+    }
+    return 0;
+}
diff --git a/ports/stm32/mpconfigport.h b/ports/stm32/mpconfigport.h
index 5a1687c07b..d802300637 100644
--- a/ports/stm32/mpconfigport.h
+++ b/ports/stm32/mpconfigport.h
@@ -224,6 +224,12 @@ extern const struct _mp_obj_module_t mp_module_onewire;
 #define SOCKET_BUILTIN_MODULE_WEAK_LINKS
 #endif
 
+#if MICROPY_PY_USSL
+#define SSL_BUILTIN_MODULE_WEAK_LINKS       { MP_ROM_QSTR(MP_QSTR_ssl), MP_ROM_PTR(&mp_module_ussl) },
+#else
+#define SSL_BUILTIN_MODULE_WEAK_LINKS
+#endif
+
 #if MICROPY_PY_NETWORK
 #define NETWORK_BUILTIN_MODULE              { MP_ROM_QSTR(MP_QSTR_network), MP_ROM_PTR(&mp_module_network) },
 #else
@@ -254,6 +260,7 @@ extern const struct _mp_obj_module_t mp_module_onewire;
     { MP_ROM_QSTR(MP_QSTR_time), MP_ROM_PTR(&mp_module_utime) }, \
     { MP_ROM_QSTR(MP_QSTR_select), MP_ROM_PTR(&mp_module_uselect) }, \
     SOCKET_BUILTIN_MODULE_WEAK_LINKS \
+    SSL_BUILTIN_MODULE_WEAK_LINKS \
     { MP_ROM_QSTR(MP_QSTR_struct), MP_ROM_PTR(&mp_module_ustruct) }, \
     { MP_ROM_QSTR(MP_QSTR_machine), MP_ROM_PTR(&machine_module) }, \
     { MP_ROM_QSTR(MP_QSTR_errno), MP_ROM_PTR(&mp_module_uerrno) }, \
@@ -267,6 +274,12 @@ extern const struct _mp_obj_module_t mp_module_onewire;
 
 #define MP_STATE_PORT MP_STATE_VM
 
+#if MICROPY_SSL_MBEDTLS
+#define MICROPY_PORT_ROOT_POINTER_MBEDTLS void **mbedtls_memory;
+#else
+#define MICROPY_PORT_ROOT_POINTER_MBEDTLS
+#endif
+
 #define MICROPY_PORT_ROOT_POINTERS \
     const char *readline_hist[8]; \
     \
@@ -295,6 +308,8 @@ extern const struct _mp_obj_module_t mp_module_onewire;
     \
     /* list of registered NICs */ \
     mp_obj_list_t mod_network_nic_list; \
+    \
+    MICROPY_PORT_ROOT_POINTER_MBEDTLS
 
 // type definitions for the specific machine