feat(hlapi): add generate_oblivious_pseudo_random on FheBool

tfhe/src/high_level_api/booleans/mod.rs

@@ -8,5 +8,6 @@ mod base;
 mod compressed;
 mod encrypt;
 mod inner;
+mod oprf;
 #[cfg(test)]
 mod tests;

tfhe/src/high_level_api/booleans/oprf.rs

@@ -0,0 +1,39 @@
+use super::FheBool;
+use crate::high_level_api::global_state;
+use crate::high_level_api::keys::InternalServerKey;
+use crate::integer::BooleanBlock;
+use concrete_csprng::seeders::Seed;
+
+impl FheBool {
+    /// Generates an encrypted boolean
+    /// taken uniformly using the given seed.
+    /// The encryted value is oblivious to the server.
+    /// It can be useful to make server random generation deterministic.
+    ///
+    /// ```rust
+    /// use tfhe::prelude::FheDecrypt;
+    /// use tfhe::{generate_keys, set_server_key, ConfigBuilder, FheBool, Seed};
+    ///
+    /// let config = ConfigBuilder::default().build();
+    /// let (client_key, server_key) = generate_keys(config);
+    ///
+    /// set_server_key(server_key);
+    ///
+    /// let ct_res = FheBool::generate_oblivious_pseudo_random(Seed(0));
+    ///
+    /// let dec_result: bool = ct_res.decrypt(&client_key);
+    /// ```
+    pub fn generate_oblivious_pseudo_random(seed: Seed) -> Self {
+        global_state::with_internal_keys(|key| match key {
+            InternalServerKey::Cpu(key) => {
+                let ct = key.pbs_key().key.generate_oblivious_pseudo_random(seed, 1);
+
+                Self::new(BooleanBlock(ct), key.tag.clone())
+            }
+            #[cfg(feature = "gpu")]
+            InternalServerKey::Cuda(_) => {
+                todo!("Cuda devices do not yet support oblivious pseudo random generation")
+            }
+        })
+    }
+}