px5g uses a 512 bit RSA key by default, for rsakey without a size and
for selfsigned without -newkey. mbedtls 3.6 refuses to generate RSA
keys smaller than MBEDTLS_RSA_GEN_KEY_MIN_BITS, which is 1024 bits, so
both commands fail with "error: key generation failed". OpenWrt uses
mbedtls 3.6 since 24.10.
Use 2048 bits as the default RSA key size, like px5g-wolfssl and
OpenSSL do.
Signed-off-by: Josef Schlehofer <pepe.schlehofer@gmail.com>
Link: https://github.com/openwrt/openwrt/pull/25629
Signed-off-by: Robert Marko <robimarko@gmail.com>