hal: move TestingRandom to platform host

diff --git a/src/rust/bitbox-platform-host/src/lib.rs b/src/rust/bitbox-platform-host/src/lib.rs
index d12d0dc..d9b8817 100644
--- a/src/rust/bitbox-platform-host/src/lib.rs
+++ b/src/rust/bitbox-platform-host/src/lib.rs
@@ -8,6 +8,7 @@ extern crate std;
 
 pub mod eeprom;
 pub mod memory;
+pub mod random;
 pub mod sd;
 pub mod securechip;
 pub mod timer;
diff --git a/src/rust/bitbox-platform-host/src/random.rs b/src/rust/bitbox-platform-host/src/random.rs
new file mode 100644
index 0000000..9ef37ac
--- /dev/null
+++ b/src/rust/bitbox-platform-host/src/random.rs
@@ -0,0 +1,79 @@
+// SPDX-License-Identifier: Apache-2.0
+use alloc::collections::VecDeque;
+
+use bitcoin::hashes::{Hash, sha256};
+use hex_lit::hex;
+
+pub struct TestingRandom {
+    mock_next_values: VecDeque<[u8; 32]>,
+    counter: u32,
+}
+
+impl TestingRandom {
+    pub const FACTORY_RANDOMNESS: [u8; 32] =
+        hex!("f71df5932e61dbaab9b9eca90e59c4b45ec91fadf803db15578c260c608eb46b");
+
+    pub fn new() -> Self {
+        Self {
+            mock_next_values: VecDeque::new(),
+            counter: 0,
+        }
+    }
+
+    pub fn mock_next(&mut self, value: [u8; 32]) {
+        self.mock_next_values.push_back(value)
+    }
+
+    fn next_value(&mut self) -> [u8; 32] {
+        self.counter += 1;
+        if let Some(value) = self.mock_next_values.pop_front() {
+            value
+        } else {
+            let hash = sha256::Hash::hash(&self.counter.to_be_bytes());
+            hash.to_byte_array()
+        }
+    }
+}
+
+impl bitbox_hal::Random for TestingRandom {
+    fn factory_randomness(&mut self) -> &'static [u8; 32] {
+        &Self::FACTORY_RANDOMNESS
+    }
+
+    fn mcu_32_bytes(&mut self, out: &mut [u8; 32]) {
+        *out = self.next_value();
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use bitbox_hal::Random;
+    use hex_lit::hex;
+
+    #[test]
+    fn test_mcu_32_bytes() {
+        let mut random = TestingRandom::new();
+        let mut first = [0u8; 32];
+        let mut second = [0u8; 32];
+        random.mcu_32_bytes(&mut first);
+        random.mcu_32_bytes(&mut second);
+        assert_eq!(
+            first,
+            hex!("b40711a88c7039756fb8a73827eabe2c0fe5a0346ca7e0a104adc0fc764f528d"),
+        );
+        assert_eq!(
+            second,
+            hex!("433ebf5bc03dffa38536673207a21281612cef5faa9bc7a4d5b9be2fdb12cf1a"),
+        );
+    }
+
+    #[test]
+    fn test_factory_randomness() {
+        let mut random = TestingRandom::new();
+        let first = random.factory_randomness();
+        let second = random.factory_randomness();
+        assert_eq!(first, &TestingRandom::FACTORY_RANDOMNESS);
+        assert_eq!(second, &TestingRandom::FACTORY_RANDOMNESS);
+    }
+}
diff --git a/src/rust/bitbox02-rust/src/hal/testing.rs b/src/rust/bitbox02-rust/src/hal/testing.rs
index c3ddeaf..c35971a 100644
--- a/src/rust/bitbox02-rust/src/hal/testing.rs
+++ b/src/rust/bitbox02-rust/src/hal/testing.rs
@@ -1,14 +1,13 @@
 // SPDX-License-Identifier: Apache-2.0
 
-pub mod random;
 pub mod system;
 pub mod ui;
 
 pub use bitbox_platform_host::eeprom::FakeEeprom as TestingEeprom;
 pub use bitbox_platform_host::memory::FakeMemory as TestingMemory;
+pub use bitbox_platform_host::random::TestingRandom;
 pub use bitbox_platform_host::sd::FakeSd as TestingSd;
 pub use bitbox_platform_host::securechip::FakeSecureChip as TestingSecureChip;
-pub use random::TestingRandom;
 pub use system::TestingSystem;
 pub use ui::{Screen, TestingUi};
 
diff --git a/src/rust/bitbox02-rust/src/hal/testing/random.rs b/src/rust/bitbox02-rust/src/hal/testing/random.rs
deleted file mode 100644
index 1304d3e..0000000
--- a/src/rust/bitbox02-rust/src/hal/testing/random.rs
+++ /dev/null
@@ -1,79 +0,0 @@
-// SPDX-License-Identifier: Apache-2.0
-use alloc::collections::VecDeque;
-
-use bitcoin::hashes::{Hash, sha256};
-use hex_lit::hex;
-
-pub struct TestingRandom {
-    mock_next_values: VecDeque<[u8; 32]>,
-    counter: u32,
-}
-
-impl TestingRandom {
-    pub const FACTORY_RANDOMNESS: [u8; 32] =
-        hex!("f71df5932e61dbaab9b9eca90e59c4b45ec91fadf803db15578c260c608eb46b");
-
-    pub fn new() -> Self {
-        Self {
-            mock_next_values: VecDeque::new(),
-            counter: 0,
-        }
-    }
-
-    pub fn mock_next(&mut self, value: [u8; 32]) {
-        self.mock_next_values.push_back(value)
-    }
-
-    fn next_value(&mut self) -> [u8; 32] {
-        self.counter += 1;
-        if let Some(value) = self.mock_next_values.pop_front() {
-            value
-        } else {
-            let hash = sha256::Hash::hash(&self.counter.to_be_bytes());
-            hash.to_byte_array()
-        }
-    }
-}
-
-impl crate::hal::Random for TestingRandom {
-    fn factory_randomness(&mut self) -> &'static [u8; 32] {
-        &Self::FACTORY_RANDOMNESS
-    }
-
-    fn mcu_32_bytes(&mut self, out: &mut [u8; 32]) {
-        *out = self.next_value();
-    }
-}
-
-#[cfg(test)]
-mod tests {
-    use super::*;
-    use crate::hal::Random;
-    use hex_lit::hex;
-
-    #[test]
-    fn test_mcu_32_bytes() {
-        let mut random = TestingRandom::new();
-        let mut first = [0u8; 32];
-        let mut second = [0u8; 32];
-        random.mcu_32_bytes(&mut first);
-        random.mcu_32_bytes(&mut second);
-        assert_eq!(
-            first,
-            hex!("b40711a88c7039756fb8a73827eabe2c0fe5a0346ca7e0a104adc0fc764f528d"),
-        );
-        assert_eq!(
-            second,
-            hex!("433ebf5bc03dffa38536673207a21281612cef5faa9bc7a4d5b9be2fdb12cf1a"),
-        );
-    }
-
-    #[test]
-    fn test_factory_randomness() {
-        let mut random = TestingRandom::new();
-        let first = random.factory_randomness();
-        let second = random.factory_randomness();
-        assert_eq!(first, &TestingRandom::FACTORY_RANDOMNESS);
-        assert_eq!(second, &TestingRandom::FACTORY_RANDOMNESS);
-    }
-}
diff --git a/src/rust/bitbox02-rust/src/hal/testing/ui.rs b/src/rust/bitbox02-rust/src/hal/testing/ui.rs
index 7b4733c..ae1823c 100644
--- a/src/rust/bitbox02-rust/src/hal/testing/ui.rs
+++ b/src/rust/bitbox02-rust/src/hal/testing/ui.rs
@@ -306,13 +306,13 @@ impl<'a> TestingUi<'a> {
     /// Push one mocked 16-bit random value in the format consumed by
     /// `workflow::mnemonic::create_random_unique_words()` (its local `rand16`
     /// helper reads the first two bytes big-endian).
-    pub fn mock_next_u16(random: &mut super::random::TestingRandom, value: u16) {
+    pub fn mock_next_u16(random: &mut super::TestingRandom, value: u16) {
         random.mock_next(Self::u16_to_rand(value));
     }
 
     /// Configure random values for one `create_random_unique_words()` call so that
     /// the correct answer is placed at choice index 2 in a 5-entry list.
-    pub fn prepare_mnemonic_quiz_word_random(random: &mut super::random::TestingRandom) {
+    pub fn prepare_mnemonic_quiz_word_random(random: &mut super::TestingRandom) {
         for value in [2u16, 0, 1, 2, 3] {
             Self::mock_next_u16(random, value);
         }
@@ -323,7 +323,7 @@ impl<'a> TestingUi<'a> {
     /// This prepares the quiz so the correct answer is always at choice index 2.
     pub fn prepare_show_and_confirm_mnemonic(
         &mut self,
-        random: &mut super::random::TestingRandom,
+        random: &mut super::TestingRandom,
         num_words: usize,
     ) {
         for _ in 0..num_words {