✨ Compression and encryption for the cached search results (#443)

* attempt1

* rough draft

* add features and their optional dependancies

* add encryption and compression error variants

* add a sample implementation to cache trait

* Update src/cache/cacher.rs

Co-authored-by: neon_arch <[email protected]>

* adjust comment so feature flag would apply?

* adjust feature flag so it applies?

* formatting

* Update src/cache/cacher.rs

update documentation

Co-authored-by: neon_arch <[email protected]>

* [features]Add base64 and chacha20 dependencies for compress-cache-results and encrypt-cache-results

* move encryption key and cipher logic to separate sub module

* added cacha20 and cec-results feature

* added cacha20 and cec-results feature

* added compression and encryption helper functions to trait implementations

* added compression and encryption implementation for inMemoryCache

* base64 is only requried when redis-cache feature is enabled

* add error case for base64 and encryption/compression implementation to redisCache

* Refactor cacher to remove regex dependency

* fmt cache error and cacher

* Update Cargo.toml

disabling the unneeded default-features

Co-authored-by: neon_arch <[email protected]>

* fix unused import warning for mimalloc

* remove deprecated method

* add doc comments for encryption module

* fix known bugs and use cfg-if module

* make cfg-if an optional dependency

* use feature-flag instead of maco lint

* add comment to explain type complexity

* bump app version

* Update src/cache/encryption.rs

Co-authored-by: neon_arch <[email protected]>

* fixed type complexity and add docs for types

---------

Co-authored-by: Spencer Najib <[email protected]>
Co-authored-by: alamin655 <[email protected]>
Co-authored-by: mergify[bot] <37929162+mergify[bot]@users.noreply.github.com>
Co-authored-by: neon_arch <[email protected]>
Co-authored-by: Spencerjibz <[email protected]>
Co-authored-by: spencer <spencer@DESKTOP-SIF13AR>

Cargo.lock

@@ -243,6 +243,16 @@ version = "1.0.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "f26201604c87b1e01bd3d98f8d5d9a8fcbb815e8cedb41ffccbeb4bf593a35fe"
 
+[[package]]
+name = "aead"
+version = "0.5.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "d122413f284cf2d62fb1b7db97e02edb8cda96d769b16e443a4f6195e35662b0"
+dependencies = [
+ "crypto-common",
+ "generic-array",
+]
+
 [[package]]
 name = "ahash"
 version = "0.7.7"
@@ -600,6 +610,30 @@ version = "1.0.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "baf1de4339761588bc0619e3cbc0120ee582ebb74b53b4efbf79117bd2da40fd"
 
+[[package]]
+name = "chacha20"
+version = "0.9.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "c3613f74bd2eac03dad61bd53dbe620703d4371614fe0bc3b9f04dd36fe4e818"
+dependencies = [
+ "cfg-if 1.0.0",
+ "cipher",
+ "cpufeatures",
+]
+
+[[package]]
+name = "chacha20poly1305"
+version = "0.10.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "10cd79432192d1c0f4e1a0fef9527696cc039165d729fb41b3f4f4f354c2dc35"
+dependencies = [
+ "aead",
+ "chacha20",
+ "cipher",
+ "poly1305",
+ "zeroize",
+]
+
 [[package]]
 name = "ci_info"
 version = "0.10.2"
@@ -636,6 +670,17 @@ dependencies = [
  "half",
 ]
 
+[[package]]
+name = "cipher"
+version = "0.4.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "773f3b9af64447d2ce9850330c473515014aa235e6a783b02db81ff39e4a3dad"
+dependencies = [
+ "crypto-common",
+ "inout",
+ "zeroize",
+]
+
 [[package]]
 name = "clap"
 version = "4.4.12"
@@ -897,6 +942,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "1bfb12502f3fc46cca1bb51ac28df9d618d813cdc3d2f25b9fe775a34af26bb3"
 dependencies = [
  "generic-array",
+ "rand_core 0.6.4",
  "typenum",
 ]
 
@@ -1709,6 +1755,15 @@ dependencies = [
  "hashbrown 0.14.3",
 ]
 
+[[package]]
+name = "inout"
+version = "0.1.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "a0c10553d664a4d0bcff9f4215d0aac67a639cc68ef660840afe309b807bc9f5"
+dependencies = [
+ "generic-array",
+]
+
 [[package]]
 name = "iovec"
 version = "0.1.4"
@@ -2219,6 +2274,12 @@ version = "11.1.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "0ab1bc2a289d34bd04a330323ac98a1b4bc82c9d9fcb1e66b63caa84da26b575"
 
+[[package]]
+name = "opaque-debug"
+version = "0.3.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "624a8340c38c1b80fd549087862da4ba43e08858af025b236e509b6649fc13d5"
+
 [[package]]
 name = "openssl"
 version = "0.10.62"
@@ -2521,6 +2582,17 @@ version = "0.3.28"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "69d3587f8a9e599cc7ec2c00e331f71c4e69a5f9a4b8a6efd5b07466b9736f9a"
 
+[[package]]
+name = "poly1305"
+version = "0.8.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "8159bd90725d2df49889a078b54f4f79e87f1f8a8444194cdca81d38f5393abf"
+dependencies = [
+ "cpufeatures",
+ "opaque-debug",
+ "universal-hash",
+]
+
 [[package]]
 name = "powerfmt"
 version = "0.2.0"
@@ -3392,6 +3464,12 @@ version = "0.3.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "b1884d1bc09741d466d9b14e6d37ac89d6909cbcac41dd9ae982d4d063bbedfc"
 
+[[package]]
+name = "subtle"
+version = "2.5.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "81cdd64d312baedb58e21336b31bc043b77e01cc99033ce76ef539f78e965ebc"
+
 [[package]]
 name = "syn"
 version = "0.15.44"
@@ -3877,6 +3955,16 @@ version = "0.2.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "f962df74c8c05a667b5ee8bcf162993134c104e96440b663c8daa176dc772d8c"
 
+[[package]]
+name = "universal-hash"
+version = "0.5.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "fc1de2c688dc15305988b563c3854064043356019f97a4b46276fe734c4f07ea"
+dependencies = [
+ "crypto-common",
+ "subtle",
+]
+
 [[package]]
 name = "untrusted"
 version = "0.9.0"
@@ -4058,7 +4146,7 @@ checksum = "1778a42e8b3b90bff8d0f5032bf22250792889a5cdc752aa0020c84abe3aaf10"
 
 [[package]]
 name = "websurfx"
-version = "1.7.3"
+version = "1.9.0"
 dependencies = [
  "actix-cors",
  "actix-files",
@@ -4066,7 +4154,12 @@ dependencies = [
  "actix-web",
  "async-once-cell",
  "async-trait",
+ "base64 0.21.5",
  "blake3",
+ "brotli",
+ "cfg-if 1.0.0",
+ "chacha20",
+ "chacha20poly1305",
  "criterion",
  "dhat",
  "env_logger",
@@ -4328,3 +4421,9 @@ dependencies = [
  "quote 1.0.33",
  "syn 2.0.43",
 ]
+
+[[package]]
+name = "zeroize"
+version = "1.7.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "525b4ec142c6b68a2d10f01f7bbf6755599ca3f81ea53b8431b7dd348f5fdb2d"

Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "websurfx"
-version = "1.7.3"
+version = "1.9.0"
 edition = "2021"
 description = "An open-source alternative to Searx that provides clean, ad-free, and organic results with incredible speed while keeping privacy and security in mind."
 repository = "https://github.com/neon-mmd/websurfx"
@@ -38,6 +38,11 @@ mimalloc = { version = "0.1.38", default-features = false }
 async-once-cell = {version="0.5.3", default-features=false}
 actix-governor = {version="0.5.0", default-features=false}
 mini-moka = { version="0.10", optional = true, default-features=false, features=["sync"]}
+brotli = { version = "3.4.0", default-features = false, features=["std"], optional=true}
+chacha20poly1305={version="0.10.1", default-features=false, features=["alloc","getrandom"], optional=true}
+chacha20 = {version="0.9.1", default-features=false, optional=true}
+base64 = {version="0.21.5", default-features=false, features=["std"], optional=true}
+cfg-if = {version="1.0.0", default-features=false,optional=true}
 
 [dev-dependencies]
 rusty-hook = {version="^0.11.2", default-features=false}
@@ -78,4 +83,8 @@ strip = "debuginfo"
 default = ["memory-cache"]
 dhat-heap = ["dep:dhat"] 
 memory-cache = ["dep:mini-moka"]
-redis-cache = ["dep:redis"]
+redis-cache = ["dep:redis","dep:base64"]
+compress-cache-results = ["dep:brotli","dep:cfg-if"]
+encrypt-cache-results = ["dep:chacha20poly1305","dep:chacha20"]
+cec-cache-results = ["compress-cache-results","encrypt-cache-results"]
+

src/bin/websurfx.rs

@@ -2,8 +2,9 @@
 //!
 //! This module contains the main function which handles the logging of the application to the
 //! stdout and handles the command line arguments provided and launches the `websurfx` server.
-
+#[cfg(not(feature = "dhat-heap"))]
 use mimalloc::MiMalloc;
+
 use std::net::TcpListener;
 use websurfx::{cache::cacher::create_cache, config::parser::Config, run};
 

src/cache/cacher.rs

@@ -4,6 +4,7 @@
 use error_stack::Report;
 #[cfg(feature = "memory-cache")]
 use mini_moka::sync::Cache as MokaCache;
+
 #[cfg(feature = "memory-cache")]
 use std::time::Duration;
 use tokio::sync::Mutex;
@@ -14,6 +15,9 @@ use super::error::CacheError;
 #[cfg(feature = "redis-cache")]
 use super::redis_cacher::RedisCache;
 
+#[cfg(any(feature = "encrypt-cache-results", feature = "cec-cache-results"))]
+use super::encryption::*;
+
 /// Abstraction trait for common methods provided by a cache backend.
 #[async_trait::async_trait]
 pub trait Cacher: Send + Sync {
@@ -69,6 +73,237 @@ pub trait Cacher: Send + Sync {
     fn hash_url(&self, url: &str) -> String {
         blake3::hash(url.as_bytes()).to_string()
     }
+
+    /// A helper function that returns  either encrypted or decrypted results.
+    ///  Feature flags (**encrypt-cache-results or cec-cache-results**) are required  for this to work.
+    ///
+    /// # Arguments
+    ///
+    /// * `bytes` - It takes a slice of bytes as an argument.
+    /// * `encrypt` - A boolean to choose whether to encrypt or decrypt the bytes
+
+    ///
+    /// # Error
+    /// Returns  either encrypted or decrypted bytes on success otherwise it returns a CacheError
+    /// on failure.
+    #[cfg(any(
+      //  feature = "compress-cache-results",
+        feature = "encrypt-cache-results",
+        feature = "cec-cache-results"
+    ))]
+    fn encrypt_or_decrypt_results(
+        &mut self,
+        mut bytes: Vec<u8>,
+        encrypt: bool,
+    ) -> Result<Vec<u8>, Report<CacheError>> {
+        use chacha20poly1305::{
+            aead::{Aead, AeadCore, KeyInit, OsRng},
+            ChaCha20Poly1305,
+        };
+
+        let cipher = CIPHER.get_or_init(|| {
+            let key = ChaCha20Poly1305::generate_key(&mut OsRng);
+            ChaCha20Poly1305::new(&key)
+        });
+
+        let encryption_key = ENCRYPTION_KEY.get_or_init(
+            || ChaCha20Poly1305::generate_nonce(&mut OsRng), // 96-bits; unique per message
+        );
+
+        bytes = if encrypt {
+            cipher
+                .encrypt(encryption_key, bytes.as_ref())
+                .map_err(|_| CacheError::EncryptionError)?
+        } else {
+            cipher
+                .decrypt(encryption_key, bytes.as_ref())
+                .map_err(|_| CacheError::EncryptionError)?
+        };
+
+        Ok(bytes)
+    }
+
+    /// A helper function that returns compressed results.
+    /// Feature flags (**compress-cache-results or cec-cache-results**) are required  for this to work.
+    ///
+    /// # Arguments
+    ///
+    /// * `bytes` - It takes a slice of bytes as an argument.
+
+    ///
+    /// # Error
+    /// Returns the compressed bytes on success otherwise it returns a CacheError
+    /// on failure.
+    #[cfg(any(feature = "compress-cache-results", feature = "cec-cache-results"))]
+    fn compress_results(&mut self, mut bytes: Vec<u8>) -> Result<Vec<u8>, Report<CacheError>> {
+        use std::io::Write;
+        let mut writer = brotli::CompressorWriter::new(Vec::new(), 4096, 11, 22);
+        writer
+            .write_all(&bytes)
+            .map_err(|_| CacheError::CompressionError)?;
+        bytes = writer.into_inner();
+        Ok(bytes)
+    }
+
+    /// A helper function that returns compressed-encrypted results.
+    /// Feature flag (**cec-cache-results**) is required  for this to work.
+    ///
+    /// # Arguments
+    ///
+    /// * `bytes` - It takes a slice of bytes as an argument.
+
+    ///
+    /// # Error
+    /// Returns the compressed and encrypted bytes on success otherwise it returns a CacheError
+    /// on failure.
+    #[cfg(feature = "cec-cache-results")]
+    fn compress_encrypt_compress_results(
+        &mut self,
+        mut bytes: Vec<u8>,
+    ) -> Result<Vec<u8>, Report<CacheError>> {
+        // compress first
+        bytes = self.compress_results(bytes)?;
+        // encrypt
+        bytes = self.encrypt_or_decrypt_results(bytes, true)?;
+
+        // compress again;
+        bytes = self.compress_results(bytes)?;
+
+        Ok(bytes)
+    }
+
+    /// A helper function that returns compressed results.
+    /// Feature flags (**compress-cache-results or cec-cache-results**) are required  for this to work.
+    /// If bytes where
+    /// # Arguments
+    ///
+    /// * `bytes` - It takes a slice of bytes as an argument.
+
+    ///
+    /// # Error
+    /// Returns the uncompressed bytes on success otherwise it returns a CacheError
+    /// on failure.
+
+    #[cfg(any(feature = "compress-cache-results", feature = "cec-cache-results"))]
+    fn decompress_results(&mut self, bytes: &[u8]) -> Result<Vec<u8>, Report<CacheError>> {
+        cfg_if::cfg_if! {
+             if #[cfg(feature = "compress-cache-results")]
+            {
+               decompress_util(bytes)
+
+            }
+            else if  #[cfg(feature = "cec-cache-results")]
+            {
+                let decompressed = decompress_util(bytes)?;
+                let decrypted = self.encrypt_or_decrypt_results(decompressed, false)?;
+
+                decompress_util(&decrypted)
+
+            }
+        }
+    }
+
+    /// A helper function that compresses or encrypts search results before they're inserted into a cache store
+
+    /// # Arguments
+    ///
+    /// * `search_results` - A reference to the search_Results to process.
+    ///
+
+    ///
+    /// # Error
+    /// Returns a Vec of compressed or encrypted bytes on success otherwise it returns a CacheError
+    /// on failure.
+    fn pre_process_search_results(
+        &mut self,
+        search_results: &SearchResults,
+    ) -> Result<Vec<u8>, Report<CacheError>> {
+        #[allow(unused_mut)] // needs to be mutable when any of the features is enabled
+        let mut bytes: Vec<u8> = search_results.try_into()?;
+        #[cfg(feature = "compress-cache-results")]
+        {
+            let compressed = self.compress_results(bytes)?;
+            bytes = compressed;
+        }
+
+        #[cfg(feature = "encrypt-cache-results")]
+        {
+            let encrypted = self.encrypt_or_decrypt_results(bytes, true)?;
+            bytes = encrypted;
+        }
+
+        #[cfg(feature = "cec-cache-results")]
+        {
+            let compressed_encrypted_compressed = self.compress_encrypt_compress_results(bytes)?;
+            bytes = compressed_encrypted_compressed;
+        }
+
+        Ok(bytes)
+    }
+
+    /// A helper function that decompresses or decrypts search results after they're fetched from the cache-store
+
+    /// # Arguments
+    ///
+    /// * `bytes` - A Vec of bytes stores in the cache.
+    ///
+
+    ///
+    /// # Error
+    /// Returns the SearchResults struct on success otherwise it returns a CacheError
+    /// on failure.
+
+    #[allow(unused_mut)] // needs to be mutable when any of the features is enabled
+    fn post_process_search_results(
+        &mut self,
+        mut bytes: Vec<u8>,
+    ) -> Result<SearchResults, Report<CacheError>> {
+        #[cfg(feature = "compress-cache-results")]
+        {
+            let decompressed = self.decompress_results(&bytes)?;
+            bytes = decompressed
+        }
+
+        #[cfg(feature = "encrypt-cache-results")]
+        {
+            let decrypted = self.encrypt_or_decrypt_results(bytes, false)?;
+            bytes = decrypted
+        }
+
+        #[cfg(feature = "cec-cache-results")]
+        {
+            let decompressed_decrypted = self.decompress_results(&bytes)?;
+            bytes = decompressed_decrypted;
+        }
+
+        Ok(bytes.try_into()?)
+    }
+}
+
+/// A helper function that returns compressed results.
+/// Feature flags (**compress-cache-results or cec-cache-results**) are required  for this to work.
+/// If bytes where
+/// # Arguments
+///
+/// * `bytes` - It takes a slice of bytes as an argument.
+
+///
+/// # Error
+/// Returns the uncompressed bytes on success otherwise it returns a CacheError
+/// on failure.
+
+#[cfg(any(feature = "compress-cache-results", feature = "cec-cache-results"))]
+fn decompress_util(input: &[u8]) -> Result<Vec<u8>, Report<CacheError>> {
+    use std::io::Write;
+    let mut writer = brotli::DecompressorWriter::new(Vec::new(), 4096);
+
+    writer
+        .write_all(input)
+        .map_err(|_| CacheError::CompressionError)?;
+    let bytes = writer
+        .into_inner()
+        .map_err(|_| CacheError::CompressionError)?;
+    Ok(bytes)
 }
 
 #[cfg(feature = "redis-cache")]
@@ -85,10 +320,14 @@ impl Cacher for RedisCache {
     }
 
     async fn cached_results(&mut self, url: &str) -> Result<SearchResults, Report<CacheError>> {
+        use base64::Engine;
         let hashed_url_string: &str = &self.hash_url(url);
-        let json = self.cached_json(hashed_url_string).await?;
-        Ok(serde_json::from_str::<SearchResults>(&json)
-            .map_err(|_| CacheError::SerializationError)?)
+        let base64_string = self.cached_json(hashed_url_string).await?;
+
+        let bytes = base64::engine::general_purpose::STANDARD_NO_PAD
+            .decode(base64_string)
+            .map_err(|_| CacheError::Base64DecodingOrEncodingError)?;
+        self.post_process_search_results(bytes)
     }
 
     async fn cache_results(
@@ -96,10 +335,29 @@ impl Cacher for RedisCache {
         search_results: &SearchResults,
         url: &str,
     ) -> Result<(), Report<CacheError>> {
-        let json =
-            serde_json::to_string(search_results).map_err(|_| CacheError::SerializationError)?;
+        use base64::Engine;
+        let bytes = self.pre_process_search_results(search_results)?;
+        let base64_string = base64::engine::general_purpose::STANDARD_NO_PAD.encode(bytes);
         let hashed_url_string = self.hash_url(url);
-        self.cache_json(&json, &hashed_url_string).await
+        self.cache_json(&base64_string, &hashed_url_string).await
+    }
+}
+/// TryInto implementation for SearchResults from Vec<u8>
+use std::convert::TryInto;
+
+impl TryInto<SearchResults> for Vec<u8> {
+    type Error = CacheError;
+
+    fn try_into(self) -> Result<SearchResults, Self::Error> {
+        serde_json::from_slice(&self).map_err(|_| CacheError::SerializationError)
+    }
+}
+
+impl TryInto<Vec<u8>> for &SearchResults {
+    type Error = CacheError;
+
+    fn try_into(self) -> Result<Vec<u8>, Self::Error> {
+        serde_json::to_vec(self).map_err(|_| CacheError::SerializationError)
     }
 }
 
@@ -107,7 +365,7 @@ impl Cacher for RedisCache {
 #[cfg(feature = "memory-cache")]
 pub struct InMemoryCache {
     /// The backend cache which stores data.
-    cache: MokaCache<String, SearchResults>,
+    cache: MokaCache<String, Vec<u8>>,
 }
 
 #[cfg(feature = "memory-cache")]
@@ -126,7 +384,7 @@ impl Cacher for InMemoryCache {
     async fn cached_results(&mut self, url: &str) -> Result<SearchResults, Report<CacheError>> {
         let hashed_url_string = self.hash_url(url);
         match self.cache.get(&hashed_url_string) {
-            Some(res) => Ok(res),
+            Some(res) => self.post_process_search_results(res),
             None => Err(Report::new(CacheError::MissingValue)),
         }
     }
@@ -137,7 +395,8 @@ impl Cacher for InMemoryCache {
         url: &str,
     ) -> Result<(), Report<CacheError>> {
         let hashed_url_string = self.hash_url(url);
-        self.cache.insert(hashed_url_string, search_results.clone());
+        let bytes = self.pre_process_search_results(search_results)?;
+        self.cache.insert(hashed_url_string, bytes);
         Ok(())
     }
 }
@@ -282,3 +541,5 @@ pub async fn create_cache(config: &Config) -> impl Cacher {
     #[cfg(not(any(feature = "memory-cache", feature = "redis-cache")))]
     return DisabledCache::build(config).await;
 }
+
+//#[cfg(feature = "Compress-cache-results")]

src/cache/encryption.rs

@@ -0,0 +1,25 @@
+use chacha20poly1305::{
+    consts::{B0, B1},
+    ChaChaPoly1305,
+};
+use std::sync::OnceLock;
+
+use chacha20::{
+    cipher::{
+        generic_array::GenericArray,
+        typenum::{UInt, UTerm},
+        StreamCipherCoreWrapper,
+    },
+    ChaChaCore,
+};
+
+/// The ChaCha20 core wrapped in a stream cipher for use in ChaCha20-Poly1305 authenticated encryption.
+type StreamCipherCoreWrapperType =
+    StreamCipherCoreWrapper<ChaChaCore<UInt<UInt<UInt<UInt<UTerm, B1>, B0>, B1>, B0>>>;
+/// Our ChaCha20-Poly1305 cipher instance, lazily initialized.
+pub static CIPHER: OnceLock<ChaChaPoly1305<StreamCipherCoreWrapperType>> = OnceLock::new();
+
+/// The type alias for our encryption key, a 32-byte array.
+type GenericArrayType = GenericArray<u8, UInt<UInt<UInt<UInt<UTerm, B1>, B1>, B0>, B0>>;
+/// Our encryption key, lazily initialized.
+pub static ENCRYPTION_KEY: OnceLock<GenericArrayType> = OnceLock::new();

src/cache/error.rs

@@ -18,6 +18,12 @@ pub enum CacheError {
     SerializationError,
     /// Returned when the value is missing.
     MissingValue,
+    /// whenever encryption or decryption of cache results fails
+    EncryptionError,
+    /// Whenever compression of  the cache results fails
+    CompressionError,
+    /// Whenever base64 decoding failed
+    Base64DecodingOrEncodingError,
 }
 
 impl fmt::Display for CacheError {
@@ -43,6 +49,18 @@ impl fmt::Display for CacheError {
             CacheError::SerializationError => {
                 write!(f, "Unable to serialize, deserialize from the cache")
             }
+
+            CacheError::EncryptionError => {
+                write!(f, "Failed to encrypt or decrypt cache-results")
+            }
+
+            CacheError::CompressionError => {
+                write!(f, "failed to compress or uncompress cache results")
+            }
+
+            CacheError::Base64DecodingOrEncodingError => {
+                write!(f, "base64 encoding or decoding failed")
+            }
         }
     }
 }

src/cache/mod.rs

@@ -1,7 +1,11 @@
 //! This module provides the modules which provide the functionality to cache the aggregated
 //! results fetched and aggregated from the upstream search engines in a json format.
-
 pub mod cacher;
+
+#[cfg(any(feature = "encrypt-cache-results", feature = "cec-cache-results"))]
+/// encryption module contains encryption utils such the cipher and key
+pub mod encryption;
 pub mod error;
+
 #[cfg(feature = "redis-cache")]
 pub mod redis_cacher;

src/cache/redis_cacher.rs

@@ -44,7 +44,7 @@ impl RedisCache {
         let mut tasks: Vec<_> = Vec::new();
 
         for _ in 0..pool_size {
-            tasks.push(client.get_tokio_connection_manager());
+            tasks.push(client.get_connection_manager());
         }
 
         let redis_cache = RedisCache {