RNG in no_std

[xFranv8]

Hello,

I am trying to connect to a Mqtt broker with TLS from my rp pico with rust.

let mut rng = RoscRng;
let mut tls_connection: TlsConnection<_, Aes256GcmSha384> =
        TlsConnection::new(tcp_socket, &mut record_read_buf, &mut record_write_buf);

  tls_connection
      .open(TlsContext::new(
          &tls_config,
          UnsecureProvider::new::<Aes256GcmSha384>(rng),
      ))
      .await
      .unwrap();

I am using

use embassy_rp::clocks::RoscRng;
use rand::RngCore;

But receive the following error:

error[E0277]: the trait bound `RoscRng: CryptoRng` is not satisfied
   --> src/main.rs:177:5
    |
177 | /     tls_connection
178 | |         .open(TlsContext::new(
179 | |             &tls_config,
180 | |             UnsecureProvider::new::<Aes256GcmSha384>(rng),
181 | |         ))
    | |__________^ the trait `CryptoRng` is not implemented for `RoscRng`
    |
    = help: the following other types implement trait `CryptoRng`:
              &'a mut R
              rand_core::block::BlockRng<R>
    = note: required for `RoscRng` to implement `CryptoRngCore`
    = note: required for `UnsecureProvider<Aes256GcmSha384, RoscRng>` to implement `CryptoProvider`
note: required by a bound in `embedded_tls::TlsConnection::<'a, Socket, CipherSuite>::open`
   --> /Users/xfranv8/.cargo/git/checkouts/embedded-tls-6ca93bdfa1e2460b/7936bc1/src/asynch.rs:78:19
    |
73  |     pub async fn open<'v, Provider>(
    |                  ---- required by a bound in this associated function
...
78  |         Provider: CryptoProvider<CipherSuite = CipherSuite>,
    |                   ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ required by this bound in `TlsConnection::<'a, Socket, CipherSuite>::open`

Any help you could provide?

Thanks!!

[newAM]

rand_core had a major update recently. Perhaps there are two incompatible versions here?

[xFranv8]

I solved modifying embassy_rp::clocks::RoscRng as follows:

impl rand_core::CryptoRng for RoscRng {}

However, now I am not able to connect to my wifi, as I get stuck waiting for a DHCP IP.

I can still connect if I comment this part:

tls_connection
        .open(TlsContext::new(
            &tls_config,
            UnsecureProvider::new::<Aes256GcmSha384>(rng),
        ))
        .await
        .unwrap();
log::info!("TLS connection opened");