diff --git a/src/fido/cbor_client_pin.c b/src/fido/cbor_client_pin.c
index d61133e..7ecbcbd 100644
--- a/src/fido/cbor_client_pin.c
+++ b/src/fido/cbor_client_pin.c
@@ -374,21 +374,7 @@ int cbor_client_pin(const uint8_t *data, size_t len) {
             CBOR_CHECK(cbor_encoder_create_map(&encoder, &mapEncoder, 1));
             CBOR_CHECK(cbor_encode_uint(&mapEncoder, 0x01));
 
-            CBOR_CHECK(cbor_encoder_create_map(&mapEncoder, &mapEncoder2,  5));
-            CBOR_CHECK(cbor_encode_uint(&mapEncoder2, 1));
-            CBOR_CHECK(cbor_encode_uint(&mapEncoder2, 2));
-            CBOR_CHECK(cbor_encode_uint(&mapEncoder2, 3));
-            CBOR_CHECK(cbor_encode_negative_int(&mapEncoder2, -FIDO2_ALG_ECDH_ES_HKDF_256));
-            CBOR_CHECK(cbor_encode_negative_int(&mapEncoder2, 1));
-            CBOR_CHECK(cbor_encode_uint(&mapEncoder2, FIDO2_CURVE_P256));
-            CBOR_CHECK(cbor_encode_negative_int(&mapEncoder2, 2));
-            uint8_t pkey[32];
-            mbedtls_mpi_write_binary(&hkey.ctx.mbed_ecdh.Q.X, pkey, 32);
-            CBOR_CHECK(cbor_encode_byte_string(&mapEncoder2, pkey, 32));
-            CBOR_CHECK(cbor_encode_negative_int(&mapEncoder2, 3));
-            mbedtls_mpi_write_binary(&hkey.ctx.mbed_ecdh.Q.Y, pkey, 32);
-            CBOR_CHECK(cbor_encode_byte_string(&mapEncoder2, pkey, 32));
-            CBOR_CHECK(cbor_encoder_close_container(&mapEncoder, &mapEncoder2));
+            CBOR_CHECK(COSE_key_shared(&hkey, &mapEncoder, &mapEncoder2));
         }
         else if (pinUvAuthProtocol == 0) {
             CBOR_ERROR(CTAP2_ERR_MISSING_PARAMETER);
diff --git a/src/fido/cbor_cred_mgmt.c b/src/fido/cbor_cred_mgmt.c
index d9705fa..13ee3f6 100644
--- a/src/fido/cbor_cred_mgmt.c
+++ b/src/fido/cbor_cred_mgmt.c
@@ -309,21 +309,7 @@ int cbor_cred_mgmt(const uint8_t *data, size_t len) {
         CBOR_CHECK(cbor_encoder_close_container(&mapEncoder, &mapEncoder2));
 
         CBOR_CHECK(cbor_encode_uint(&mapEncoder, 0x08));
-        CBOR_CHECK(cbor_encoder_create_map(&mapEncoder, &mapEncoder2,  5));
-        CBOR_CHECK(cbor_encode_uint(&mapEncoder2, 1));
-        CBOR_CHECK(cbor_encode_uint(&mapEncoder2, 2));
-        CBOR_CHECK(cbor_encode_uint(&mapEncoder2, 3));
-        CBOR_CHECK(cbor_encode_negative_int(&mapEncoder2, -cred.alg));
-        CBOR_CHECK(cbor_encode_negative_int(&mapEncoder2, 1));
-        CBOR_CHECK(cbor_encode_uint(&mapEncoder2, cred.curve));
-        CBOR_CHECK(cbor_encode_negative_int(&mapEncoder2, 2));
-        uint8_t pkey[66];
-        mbedtls_mpi_write_binary(&key.Q.X, pkey, mbedtls_mpi_size(&key.Q.X));
-        CBOR_CHECK(cbor_encode_byte_string(&mapEncoder2, pkey, mbedtls_mpi_size(&key.Q.X)));
-        CBOR_CHECK(cbor_encode_negative_int(&mapEncoder2, 3));
-        mbedtls_mpi_write_binary(&key.Q.Y, pkey, mbedtls_mpi_size(&key.Q.Y));
-        CBOR_CHECK(cbor_encode_byte_string(&mapEncoder2, pkey, mbedtls_mpi_size(&key.Q.Y)));
-        CBOR_CHECK(cbor_encoder_close_container(&mapEncoder, &mapEncoder2));
+        CBOR_CHECK(COSE_key(&key, &mapEncoder, &mapEncoder2));
 
         if (subcommand == 0x04) {
             CBOR_CHECK(cbor_encode_uint(&mapEncoder, 0x09));
diff --git a/src/fido/cbor_get_info.c b/src/fido/cbor_get_info.c
index 8812376..0864725 100644
--- a/src/fido/cbor_get_info.c
+++ b/src/fido/cbor_get_info.c
@@ -91,30 +91,10 @@ int cbor_get_info() {
 
     CBOR_CHECK(cbor_encode_uint(&mapEncoder, 0x0A));
     CBOR_CHECK(cbor_encoder_create_array(&mapEncoder, &arrayEncoder, 4));
-    CBOR_CHECK(cbor_encoder_create_map(&arrayEncoder, &mapEncoder2, 2));
-    CBOR_CHECK(cbor_encode_text_stringz(&mapEncoder2, "alg"));
-    CBOR_CHECK(cbor_encode_negative_int(&mapEncoder2, -FIDO2_ALG_ES256));
-    CBOR_CHECK(cbor_encode_text_stringz(&mapEncoder2, "type"));
-    CBOR_CHECK(cbor_encode_text_stringz(&mapEncoder2, "public-key"));
-    CBOR_CHECK(cbor_encoder_close_container(&arrayEncoder, &mapEncoder2));
-    CBOR_CHECK(cbor_encoder_create_map(&arrayEncoder, &mapEncoder2, 2));
-    CBOR_CHECK(cbor_encode_text_stringz(&mapEncoder2, "alg"));
-    CBOR_CHECK(cbor_encode_negative_int(&mapEncoder2, -FIDO2_ALG_ES384));
-    CBOR_CHECK(cbor_encode_text_stringz(&mapEncoder2, "type"));
-    CBOR_CHECK(cbor_encode_text_stringz(&mapEncoder2, "public-key"));
-    CBOR_CHECK(cbor_encoder_close_container(&arrayEncoder, &mapEncoder2));
-    CBOR_CHECK(cbor_encoder_create_map(&arrayEncoder, &mapEncoder2, 2));
-    CBOR_CHECK(cbor_encode_text_stringz(&mapEncoder2, "alg"));
-    CBOR_CHECK(cbor_encode_negative_int(&mapEncoder2, -FIDO2_ALG_ES512));
-    CBOR_CHECK(cbor_encode_text_stringz(&mapEncoder2, "type"));
-    CBOR_CHECK(cbor_encode_text_stringz(&mapEncoder2, "public-key"));
-    CBOR_CHECK(cbor_encoder_close_container(&arrayEncoder, &mapEncoder2));
-    CBOR_CHECK(cbor_encoder_create_map(&arrayEncoder, &mapEncoder2, 2));
-    CBOR_CHECK(cbor_encode_text_stringz(&mapEncoder2, "alg"));
-    CBOR_CHECK(cbor_encode_negative_int(&mapEncoder2, -FIDO2_ALG_ES256K));
-    CBOR_CHECK(cbor_encode_text_stringz(&mapEncoder2, "type"));
-    CBOR_CHECK(cbor_encode_text_stringz(&mapEncoder2, "public-key"));
-    CBOR_CHECK(cbor_encoder_close_container(&arrayEncoder, &mapEncoder2));
+    CBOR_CHECK(COSE_public_key(FIDO2_ALG_ES256, &arrayEncoder, &mapEncoder2));
+    CBOR_CHECK(COSE_public_key(FIDO2_ALG_ES384, &arrayEncoder, &mapEncoder2));
+    CBOR_CHECK(COSE_public_key(FIDO2_ALG_ES512, &arrayEncoder, &mapEncoder2));
+    CBOR_CHECK(COSE_public_key(FIDO2_ALG_ES256K, &arrayEncoder, &mapEncoder2));
     CBOR_CHECK(cbor_encoder_close_container(&mapEncoder, &arrayEncoder));
 
     CBOR_CHECK(cbor_encode_uint(&mapEncoder, 0x0B));
diff --git a/src/fido/cbor_make_credential.c b/src/fido/cbor_make_credential.c
index c176408..d709d5c 100644
--- a/src/fido/cbor_make_credential.c
+++ b/src/fido/cbor_make_credential.c
@@ -369,7 +369,6 @@ int cbor_make_credential(const uint8_t *data, size_t len) {
         ext_len = cbor_encoder_get_buffer_size(&encoder, ext);
         flags |= FIDO2_AUT_FLAG_ED;
     }
-    uint8_t pkey[66];
     mbedtls_ecdsa_context ekey;
     mbedtls_ecdsa_init(&ekey);
     int ret = fido_load_key(curve, cred_id, &ekey);
@@ -386,21 +385,7 @@ int cbor_make_credential(const uint8_t *data, size_t len) {
     uint32_t ctr = get_sign_counter();
     uint8_t cbor_buf[1024];
     cbor_encoder_init(&encoder, cbor_buf, sizeof(cbor_buf), 0);
-    CBOR_CHECK(cbor_encoder_create_map(&encoder, &mapEncoder,  5));
-    CBOR_CHECK(cbor_encode_uint(&mapEncoder, 1));
-    CBOR_CHECK(cbor_encode_uint(&mapEncoder, 2));
-    CBOR_CHECK(cbor_encode_uint(&mapEncoder, 3));
-    CBOR_CHECK(cbor_encode_negative_int(&mapEncoder, -alg));
-    CBOR_CHECK(cbor_encode_negative_int(&mapEncoder, 1));
-    CBOR_CHECK(cbor_encode_uint(&mapEncoder, curve));
-    CBOR_CHECK(cbor_encode_negative_int(&mapEncoder, 2));
-    mbedtls_mpi_write_binary(&ekey.Q.X, pkey, mbedtls_mpi_size(&ekey.Q.X));
-    CBOR_CHECK(cbor_encode_byte_string(&mapEncoder, pkey, mbedtls_mpi_size(&ekey.Q.X)));
-    CBOR_CHECK(cbor_encode_negative_int(&mapEncoder, 3));
-    mbedtls_mpi_write_binary(&ekey.Q.Y, pkey, mbedtls_mpi_size(&ekey.Q.Y));
-    CBOR_CHECK(cbor_encode_byte_string(&mapEncoder, pkey, mbedtls_mpi_size(&ekey.Q.Y)));
-
-    CBOR_CHECK(cbor_encoder_close_container(&encoder, &mapEncoder));
+    CBOR_CHECK(COSE_key(&ekey, &encoder, &mapEncoder));
     size_t rs = cbor_encoder_get_buffer_size(&encoder, cbor_buf);
 
     size_t aut_data_len = 32 + 1 + 4 + (16 + 2 + cred_id_len + rs) + ext_len;
diff --git a/src/fido/cbor_vendor.c b/src/fido/cbor_vendor.c
index 5ec5b28..466bc67 100644
--- a/src/fido/cbor_vendor.c
+++ b/src/fido/cbor_vendor.c
@@ -223,22 +223,7 @@ int cbor_vendor_generic(uint8_t cmd, const uint8_t *data, size_t len) {
 
             CBOR_CHECK(cbor_encoder_create_map(&encoder, &mapEncoder, 1));
             CBOR_CHECK(cbor_encode_uint(&mapEncoder, 0x01));
-
-            CBOR_CHECK(cbor_encoder_create_map(&mapEncoder, &mapEncoder2,  5));
-            CBOR_CHECK(cbor_encode_uint(&mapEncoder2, 1));
-            CBOR_CHECK(cbor_encode_uint(&mapEncoder2, 2));
-            CBOR_CHECK(cbor_encode_uint(&mapEncoder2, 3));
-            CBOR_CHECK(cbor_encode_negative_int(&mapEncoder2, -FIDO2_ALG_ECDH_ES_HKDF_256));
-            CBOR_CHECK(cbor_encode_negative_int(&mapEncoder2, 1));
-            CBOR_CHECK(cbor_encode_uint(&mapEncoder2, FIDO2_CURVE_P256));
-            CBOR_CHECK(cbor_encode_negative_int(&mapEncoder2, 2));
-            uint8_t pkey[32];
-            mbedtls_mpi_write_binary(&hkey.ctx.mbed_ecdh.Q.X, pkey, 32);
-            CBOR_CHECK(cbor_encode_byte_string(&mapEncoder2, pkey, 32));
-            CBOR_CHECK(cbor_encode_negative_int(&mapEncoder2, 3));
-            mbedtls_mpi_write_binary(&hkey.ctx.mbed_ecdh.Q.Y, pkey, 32);
-            CBOR_CHECK(cbor_encode_byte_string(&mapEncoder2, pkey, 32));
-            CBOR_CHECK(cbor_encoder_close_container(&mapEncoder, &mapEncoder2));
+            CBOR_CHECK(COSE_key_shared(&hkey, &mapEncoder, &mapEncoder2));
             mbedtls_ecdh_free(&hkey);
         }
     }