Ok, I just fixed the problem, it works now with ECDHE-ECDSA-AES128-GCM-SHA256 and no filesystem.
For people who got the same problem, at first you need to add the following in the certs_test.h file:
/* ./certs/server-ecc.der */
static const unsigned char server_ecc_der[] =
{
0x30, 0x82, 0x03, 0x0F, 0x30, 0x82, 0x02, 0xB5, 0xA0, 0x03, 0x02, 0x01, 0x02, 0x02, 0x09, 0x00,
0xB2, 0x37, 0x31, 0x16, 0xF6, 0x5A, 0x0A, 0x06, 0x30, 0x0A, 0x06, 0x08, 0x2A, 0x86, 0x48, 0xCE,
0x3D, 0x04, 0x03, 0x02, 0x30, 0x81, 0x8F, 0x31, 0x0B, 0x30, 0x09, 0x06, 0x03, 0x55, 0x04, 0x06,
0x13, 0x02, 0x55, 0x53, 0x31, 0x13, 0x30, 0x11, 0x06, 0x03, 0x55, 0x04, 0x08, 0x0C, 0x0A, 0x57,
0x61, 0x73, 0x68, 0x69, 0x6E, 0x67, 0x74, 0x6F, 0x6E, 0x31, 0x10, 0x30, 0x0E, 0x06, 0x03, 0x55,
0x04, 0x07, 0x0C, 0x07, 0x53, 0x65, 0x61, 0x74, 0x74, 0x6C, 0x65, 0x31, 0x10, 0x30, 0x0E, 0x06,
0x03, 0x55, 0x04, 0x0A, 0x0C, 0x07, 0x45, 0x6C, 0x69, 0x70, 0x74, 0x69, 0x63, 0x31, 0x0C, 0x30,
0x0A, 0x06, 0x03, 0x55, 0x04, 0x0B, 0x0C, 0x03, 0x45, 0x43, 0x43, 0x31, 0x18, 0x30, 0x16, 0x06,
0x03, 0x55, 0x04, 0x03, 0x0C, 0x0F, 0x77, 0x77, 0x77, 0x2E, 0x77, 0x6F, 0x6C, 0x66, 0x73, 0x73,
0x6C, 0x2E, 0x63, 0x6F, 0x6D, 0x31, 0x1F, 0x30, 0x1D, 0x06, 0x09, 0x2A, 0x86, 0x48, 0x86, 0xF7,
0x0D, 0x01, 0x09, 0x01, 0x16, 0x10, 0x69, 0x6E, 0x66, 0x6F, 0x40, 0x77, 0x6F, 0x6C, 0x66, 0x73,
0x73, 0x6C, 0x2E, 0x63, 0x6F, 0x6D, 0x30, 0x1E, 0x17, 0x0D, 0x31, 0x35, 0x30, 0x35, 0x30, 0x37,
0x31, 0x38, 0x32, 0x31, 0x30, 0x31, 0x5A, 0x17, 0x0D, 0x31, 0x38, 0x30, 0x31, 0x33, 0x31, 0x31,
0x38, 0x32, 0x31, 0x30, 0x31, 0x5A, 0x30, 0x81, 0x8F, 0x31, 0x0B, 0x30, 0x09, 0x06, 0x03, 0x55,
0x04, 0x06, 0x13, 0x02, 0x55, 0x53, 0x31, 0x13, 0x30, 0x11, 0x06, 0x03, 0x55, 0x04, 0x08, 0x0C,
0x0A, 0x57, 0x61, 0x73, 0x68, 0x69, 0x6E, 0x67, 0x74, 0x6F, 0x6E, 0x31, 0x10, 0x30, 0x0E, 0x06,
0x03, 0x55, 0x04, 0x07, 0x0C, 0x07, 0x53, 0x65, 0x61, 0x74, 0x74, 0x6C, 0x65, 0x31, 0x10, 0x30,
0x0E, 0x06, 0x03, 0x55, 0x04, 0x0A, 0x0C, 0x07, 0x45, 0x6C, 0x69, 0x70, 0x74, 0x69, 0x63, 0x31,
0x0C, 0x30, 0x0A, 0x06, 0x03, 0x55, 0x04, 0x0B, 0x0C, 0x03, 0x45, 0x43, 0x43, 0x31, 0x18, 0x30,
0x16, 0x06, 0x03, 0x55, 0x04, 0x03, 0x0C, 0x0F, 0x77, 0x77, 0x77, 0x2E, 0x77, 0x6F, 0x6C, 0x66,
0x73, 0x73, 0x6C, 0x2E, 0x63, 0x6F, 0x6D, 0x31, 0x1F, 0x30, 0x1D, 0x06, 0x09, 0x2A, 0x86, 0x48,
0x86, 0xF7, 0x0D, 0x01, 0x09, 0x01, 0x16, 0x10, 0x69, 0x6E, 0x66, 0x6F, 0x40, 0x77, 0x6F, 0x6C,
0x66, 0x73, 0x73, 0x6C, 0x2E, 0x63, 0x6F, 0x6D, 0x30, 0x59, 0x30, 0x13, 0x06, 0x07, 0x2A, 0x86,
0x48, 0xCE, 0x3D, 0x02, 0x01, 0x06, 0x08, 0x2A, 0x86, 0x48, 0xCE, 0x3D, 0x03, 0x01, 0x07, 0x03,
0x42, 0x00, 0x04, 0xBB, 0x33, 0xAC, 0x4C, 0x27, 0x50, 0x4A, 0xC6, 0x4A, 0xA5, 0x04, 0xC3, 0x3C,
0xDE, 0x9F, 0x36, 0xDB, 0x72, 0x2D, 0xCE, 0x94, 0xEA, 0x2B, 0xFA, 0xCB, 0x20, 0x09, 0x39, 0x2C,
0x16, 0xE8, 0x61, 0x02, 0xE9, 0xAF, 0x4D, 0xD3, 0x02, 0x93, 0x9A, 0x31, 0x5B, 0x97, 0x92, 0x21,
0x7F, 0xF0, 0xCF, 0x18, 0xDA, 0x91, 0x11, 0x02, 0x34, 0x86, 0xE8, 0x20, 0x58, 0x33, 0x0B, 0x80,
0x34, 0x89, 0xD8, 0xA3, 0x81, 0xF7, 0x30, 0x81, 0xF4, 0x30, 0x1D, 0x06, 0x03, 0x55, 0x1D, 0x0E,
0x04, 0x16, 0x04, 0x14, 0x5D, 0x5D, 0x26, 0xEF, 0xAC, 0x7E, 0x36, 0xF9, 0x9B, 0x76, 0x15, 0x2B,
0x4A, 0x25, 0x02, 0x23, 0xEF, 0xB2, 0x89, 0x30, 0x30, 0x81, 0xC4, 0x06, 0x03, 0x55, 0x1D, 0x23,
0x04, 0x81, 0xBC, 0x30, 0x81, 0xB9, 0x80, 0x14, 0x5D, 0x5D, 0x26, 0xEF, 0xAC, 0x7E, 0x36, 0xF9,
0x9B, 0x76, 0x15, 0x2B, 0x4A, 0x25, 0x02, 0x23, 0xEF, 0xB2, 0x89, 0x30, 0xA1, 0x81, 0x95, 0xA4,
0x81, 0x92, 0x30, 0x81, 0x8F, 0x31, 0x0B, 0x30, 0x09, 0x06, 0x03, 0x55, 0x04, 0x06, 0x13, 0x02,
0x55, 0x53, 0x31, 0x13, 0x30, 0x11, 0x06, 0x03, 0x55, 0x04, 0x08, 0x0C, 0x0A, 0x57, 0x61, 0x73,
0x68, 0x69, 0x6E, 0x67, 0x74, 0x6F, 0x6E, 0x31, 0x10, 0x30, 0x0E, 0x06, 0x03, 0x55, 0x04, 0x07,
0x0C, 0x07, 0x53, 0x65, 0x61, 0x74, 0x74, 0x6C, 0x65, 0x31, 0x10, 0x30, 0x0E, 0x06, 0x03, 0x55,
0x04, 0x0A, 0x0C, 0x07, 0x45, 0x6C, 0x69, 0x70, 0x74, 0x69, 0x63, 0x31, 0x0C, 0x30, 0x0A, 0x06,
0x03, 0x55, 0x04, 0x0B, 0x0C, 0x03, 0x45, 0x43, 0x43, 0x31, 0x18, 0x30, 0x16, 0x06, 0x03, 0x55,
0x04, 0x03, 0x0C, 0x0F, 0x77, 0x77, 0x77, 0x2E, 0x77, 0x6F, 0x6C, 0x66, 0x73, 0x73, 0x6C, 0x2E,
0x63, 0x6F, 0x6D, 0x31, 0x1F, 0x30, 0x1D, 0x06, 0x09, 0x2A, 0x86, 0x48, 0x86, 0xF7, 0x0D, 0x01,
0x09, 0x01, 0x16, 0x10, 0x69, 0x6E, 0x66, 0x6F, 0x40, 0x77, 0x6F, 0x6C, 0x66, 0x73, 0x73, 0x6C,
0x2E, 0x63, 0x6F, 0x6D, 0x82, 0x09, 0x00, 0xB2, 0x37, 0x31, 0x16, 0xF6, 0x5A, 0x0A, 0x06, 0x30,
0x0C, 0x06, 0x03, 0x55, 0x1D, 0x13, 0x04, 0x05, 0x30, 0x03, 0x01, 0x01, 0xFF, 0x30, 0x0A, 0x06,
0x08, 0x2A, 0x86, 0x48, 0xCE, 0x3D, 0x04, 0x03, 0x02, 0x03, 0x48, 0x00, 0x30, 0x45, 0x02, 0x20,
0x35, 0x25, 0x33, 0xEA, 0x7C, 0x3B, 0xE2, 0x2E, 0xED, 0xE4, 0x2E, 0x9A, 0x91, 0xF1, 0xC3, 0x86,
0xFF, 0xA7, 0x27, 0x35, 0xA9, 0xF6, 0x29, 0xD6, 0xF8, 0xD5, 0x9A, 0x0B, 0x35, 0xF1, 0x21, 0xC7,
0x02, 0x21, 0x00, 0xBC, 0x79, 0xF7, 0xFD, 0x66, 0xD4, 0xD3, 0x46, 0x61, 0xE4, 0x19, 0xE5, 0xF7,
0x74, 0x03, 0x83, 0x27, 0xF8, 0x26, 0xC0, 0x86, 0x15, 0xA9, 0xE2, 0x10, 0xE3, 0xAD, 0x6B, 0xB9,
0x1C, 0x1D, 0xEB
};
static const int sizeof_server_ecc_der = sizeof(server_ecc_der);
/* ./certs/ecc-key.der */
static const unsigned char ecc_key_der[] =
{
0x30, 0x77, 0x02, 0x01, 0x01, 0x04, 0x20, 0x45, 0xB6, 0x69, 0x02, 0x73, 0x9C, 0x6C, 0x85, 0xA1,
0x38, 0x5B, 0x72, 0xE8, 0xE8, 0xC7, 0xAC, 0xC4, 0x03, 0x8D, 0x53, 0x35, 0x04, 0xFA, 0x6C, 0x28,
0xDC, 0x34, 0x8D, 0xE1, 0xA8, 0x09, 0x8C, 0xA0, 0x0A, 0x06, 0x08, 0x2A, 0x86, 0x48, 0xCE, 0x3D,
0x03, 0x01, 0x07, 0xA1, 0x44, 0x03, 0x42, 0x00, 0x04, 0xBB, 0x33, 0xAC, 0x4C, 0x27, 0x50, 0x4A,
0xC6, 0x4A, 0xA5, 0x04, 0xC3, 0x3C, 0xDE, 0x9F, 0x36, 0xDB, 0x72, 0x2D, 0xCE, 0x94, 0xEA, 0x2B,
0xFA, 0xCB, 0x20, 0x09, 0x39, 0x2C, 0x16, 0xE8, 0x61, 0x02, 0xE9, 0xAF, 0x4D, 0xD3, 0x02, 0x93,
0x9A, 0x31, 0x5B, 0x97, 0x92, 0x21, 0x7F, 0xF0, 0xCF, 0x18, 0xDA, 0x91, 0x11, 0x02, 0x34, 0x86,
0xE8, 0x20, 0x58, 0x33, 0x0B, 0x80, 0x34, 0x89, 0xD8
};
static const int sizeof_ecc_key_der = sizeof(ecc_key_der);
Without having a ECDSA certificate set at the server there will be a -501 error.
One last point: I figured out that the connection also works without having HAVE_TLS_EXTENSIONS and HAVE_SUPPORTED_CURVES.