diff --git a/src/hsm/cmd_bip_slip.c b/src/hsm/cmd_bip_slip.c
index 2a8aed7..95f8b30 100644
--- a/src/hsm/cmd_bip_slip.c
+++ b/src/hsm/cmd_bip_slip.c
@@ -265,7 +265,7 @@ int cmd_bip_slip() {
         }
         mbedtls_ecp_keypair ctx;
         uint8_t chain[32] = { 0 }, fgpt[4] = { 0 }, last_node[4] = { 0 }, key_type = 0, nodes = 0;
-        uint16_t olen = 0;
+        size_t olen = 0;
         int r =
             node_derive_path(apdu.data, apdu.nc, &ctx, chain, fgpt, &nodes, last_node, &key_type);
         if (r != CCID_OK) {
@@ -287,11 +287,11 @@ int cmd_bip_slip() {
             mbedtls_ecp_point_write_binary(&ctx.grp,
                                            &ctx.Q,
                                            MBEDTLS_ECP_PF_COMPRESSED,
-                                           (size_t *)&olen,
+                                           &olen,
                                            pubkey,
                                            sizeof(pubkey));
             memcpy(res_APDU + res_APDU_size, pubkey, olen);
-            res_APDU_size += olen;
+            res_APDU_size += (uint16_t)olen;
         }
         else if (key_type == 0x3) {
             sha256_sha256(chain, 32, chain);
diff --git a/src/hsm/cmd_cipher_sym.c b/src/hsm/cmd_cipher_sym.c
index a9aa86e..cacaac4 100644
--- a/src/hsm/cmd_cipher_sym.c
+++ b/src/hsm/cmd_cipher_sym.c
@@ -380,7 +380,7 @@ int cmd_cipher_sym() {
             if (r != 0) {
                 return SW_EXEC_ERROR();
             }
-            res_APDU_size = apdu.ne > 0 && apdu.ne < 65536 ? apdu.ne : mbedtls_md_get_size(md_info);
+            res_APDU_size = apdu.ne > 0 && apdu.ne < 65536 ? apdu.ne : (uint16_t)mbedtls_md_get_size(md_info);
         }
         else if (memcmp(oid, OID_PKCS5_PBKDF2, oid_len) == 0) {
             int iterations = 0;
@@ -412,7 +412,7 @@ int cmd_cipher_sym() {
             res_APDU_size = keylen ? keylen : (apdu.ne > 0 && apdu.ne < 65536 ? apdu.ne : 32);
         }
         else if (memcmp(oid, OID_PKCS5_PBES2, oid_len) == 0) {
-            uint16_t olen = 0;
+            size_t olen = 0;
             mbedtls_asn1_buf params =
                 {.p = aad, .len = aad_len, .tag = (MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE)};
             int r = mbedtls_pkcs5_pbes2_ext(&params,
@@ -421,12 +421,12 @@ int cmd_cipher_sym() {
                                         key_size,
                                         enc,
                                         enc_len,
-                                        res_APDU, 4096, (size_t *)&olen);
+                                        res_APDU, 4096, &olen);
             mbedtls_platform_zeroize(kdata, sizeof(kdata));
             if (r != 0) {
                 return SW_WRONG_DATA();
             }
-            res_APDU_size = olen;
+            res_APDU_size = (uint16_t)olen;
         }
         else if (memcmp(oid, OID_KDF_X963, oid_len) == 0) {
             mbedtls_md_type_t md_type = MBEDTLS_MD_SHA1;
diff --git a/src/hsm/cmd_decrypt_asym.c b/src/hsm/cmd_decrypt_asym.c
index 4f4dc5b..c76ab8f 100644
--- a/src/hsm/cmd_decrypt_asym.c
+++ b/src/hsm/cmd_decrypt_asym.c
@@ -61,10 +61,10 @@ int cmd_decrypt_asym() {
             memset(apdu.data + apdu.nc, 0, key_size - apdu.nc);
         }
         if (p2 == ALGO_RSA_DECRYPT_PKCS1 || p2 == ALGO_RSA_DECRYPT_OEP) {
-            uint16_t olen = apdu.nc;
-            r = mbedtls_rsa_pkcs1_decrypt(&ctx, random_gen, NULL, (size_t *)&olen, apdu.data, res_APDU, 512);
+            size_t olen = apdu.nc;
+            r = mbedtls_rsa_pkcs1_decrypt(&ctx, random_gen, NULL, &olen, apdu.data, res_APDU, 512);
             if (r == 0) {
-                res_APDU_size = olen;
+                res_APDU_size = (uint16_t)olen;
             }
         }
         else {
@@ -131,19 +131,19 @@ int cmd_decrypt_asym() {
             mbedtls_ecdh_free(&ctx);
             return SW_DATA_INVALID();
         }
-        uint16_t olen = 0;
+        size_t olen = 0;
         // The SmartCard-HSM returns the point result of the DH operation
         // with a leading '04'
         res_APDU[0] = 0x04;
         r =
-            mbedtls_ecdh_calc_secret(&ctx, (size_t *)&olen, res_APDU + 1, MBEDTLS_ECP_MAX_BYTES, random_gen,
+            mbedtls_ecdh_calc_secret(&ctx, &olen, res_APDU + 1, MBEDTLS_ECP_MAX_BYTES, random_gen,
                                      NULL);
         mbedtls_ecdh_free(&ctx);
         if (r != 0) {
             return SW_EXEC_ERROR();
         }
         if (p2 == ALGO_EC_DH) {
-            res_APDU_size = olen + 1;
+            res_APDU_size = (uint16_t)(olen + 1);
         }
         else {
             res_APDU_size = 0;
diff --git a/src/hsm/cmd_extras.c b/src/hsm/cmd_extras.c
index cddb33e..a5c4499 100644
--- a/src/hsm/cmd_extras.c
+++ b/src/hsm/cmd_extras.c
@@ -111,9 +111,9 @@ int cmd_extras() {
             memcpy(mse.Qpt, apdu.data, sizeof(mse.Qpt));
 
             uint8_t buf[MBEDTLS_ECP_MAX_BYTES];
-            uint16_t olen = 0;
+            size_t olen = 0;
             ret = mbedtls_ecdh_calc_secret(&hkey,
-                                           (size_t *)&olen,
+                                           &olen,
                                            buf,
                                            MBEDTLS_ECP_MAX_BYTES,
                                            random_gen,
@@ -141,7 +141,7 @@ int cmd_extras() {
             ret = mbedtls_ecp_point_write_binary(&hkey.ctx.mbed_ecdh.grp,
                                                  &hkey.ctx.mbed_ecdh.Q,
                                                  MBEDTLS_ECP_PF_UNCOMPRESSED,
-                                                 (size_t *)&olen,
+                                                 &olen,
                                                  res_APDU,
                                                  4096);
             mbedtls_ecdh_free(&hkey);
@@ -149,7 +149,7 @@ int cmd_extras() {
                 return SW_EXEC_ERROR();
             }
             mse.init = true;
-            res_APDU_size = olen;
+            res_APDU_size = (uint16_t)olen;
         }
         else if (P2(apdu) == 0x02 || P2(apdu) == 0x03 || P2(apdu) == 0x04) {
             if (mse.init == false) {
diff --git a/src/hsm/cmd_signature.c b/src/hsm/cmd_signature.c
index 42a7272..8afb737 100644
--- a/src/hsm/cmd_signature.c
+++ b/src/hsm/cmd_signature.c
@@ -276,19 +276,19 @@ int cmd_signature() {
             }
             return SW_EXEC_ERROR();
         }
-        uint16_t olen = 0;
+        size_t olen = 0;
         uint8_t buf[MBEDTLS_ECDSA_MAX_LEN];
         if (mbedtls_ecdsa_write_signature(&ctx, md, apdu.data, apdu.nc, buf, MBEDTLS_ECDSA_MAX_LEN,
-                                          (size_t *)&olen, random_gen, NULL) != 0) {
+                                          &olen, random_gen, NULL) != 0) {
             mbedtls_ecdsa_free(&ctx);
             return SW_EXEC_ERROR();
         }
         memcpy(res_APDU, buf, olen);
-        res_APDU_size = olen;
+        res_APDU_size = (uint16_t)olen;
         mbedtls_ecdsa_free(&ctx);
     }
     else if (p2 == ALGO_HD) {
-        uint16_t olen = 0;
+        size_t olen = 0;
         uint8_t buf[MBEDTLS_ECDSA_MAX_LEN];
         if (hd_context.grp.id == MBEDTLS_ECP_DP_NONE) {
             return SW_CONDITIONS_NOT_SATISFIED();
@@ -299,12 +299,12 @@ int cmd_signature() {
         md = MBEDTLS_MD_SHA256;
         if (mbedtls_ecdsa_write_signature(&hd_context, md, apdu.data, apdu.nc, buf,
                                           MBEDTLS_ECDSA_MAX_LEN,
-                                          (size_t *)&olen, random_gen, NULL) != 0) {
+                                          &olen, random_gen, NULL) != 0) {
             mbedtls_ecdsa_free(&hd_context);
             return SW_EXEC_ERROR();
         }
         memcpy(res_APDU, buf, olen);
-        res_APDU_size = olen;
+        res_APDU_size = (uint16_t)olen;
         mbedtls_ecdsa_free(&hd_context);
         hd_keytype = 0;
     }
diff --git a/src/hsm/kek.c b/src/hsm/kek.c
index 7f9dea6..4d317b8 100644
--- a/src/hsm/kek.c
+++ b/src/hsm/kek.c
@@ -387,15 +387,15 @@ int dkek_encode_key(uint8_t id,
         mbedtls_mpi_write_binary(&ecdsa->grp.N, kb + 8 + kb_len, mbedtls_mpi_size(&ecdsa->grp.N));
         kb_len += (uint16_t)mbedtls_mpi_size(&ecdsa->grp.N);
 
-        uint16_t olen = 0;
+        size_t olen = 0;
         mbedtls_ecp_point_write_binary(&ecdsa->grp,
                                        &ecdsa->grp.G,
                                        MBEDTLS_ECP_PF_UNCOMPRESSED,
-                                       (size_t *)&olen,
+                                       &olen,
                                        kb + 8 + kb_len + 2,
                                        sizeof(kb) - 8 - kb_len - 2);
-        put_uint16_t(olen, kb + 8 + kb_len);
-        kb_len += 2 + olen;
+        put_uint16_t((uint16_t)olen, kb + 8 + kb_len);
+        kb_len += 2 + (uint16_t)olen;
 
         put_uint16_t((uint16_t)mbedtls_mpi_size(&ecdsa->d), kb + 8 + kb_len); kb_len += 2;
         mbedtls_mpi_write_binary(&ecdsa->d, kb + 8 + kb_len, mbedtls_mpi_size(&ecdsa->d));
@@ -404,11 +404,11 @@ int dkek_encode_key(uint8_t id,
         mbedtls_ecp_point_write_binary(&ecdsa->grp,
                                        &ecdsa->Q,
                                        MBEDTLS_ECP_PF_UNCOMPRESSED,
-                                       (size_t *)&olen,
+                                       &olen,
                                        kb + 8 + kb_len + 2,
                                        sizeof(kb) - 8 - kb_len - 2);
-        put_uint16_t(olen, kb + 8 + kb_len);
-        kb_len += 2 + olen;
+        put_uint16_t((uint16_t)olen, kb + 8 + kb_len);
+        kb_len += 2 + (uint16_t)olen;
 
         algo = (uint8_t *) "\x00\x0A\x04\x00\x7F\x00\x07\x02\x02\x02\x02\x03";
         algo_len = 12;