From 6810557942a3174ff484f970f7b643d10ba1a6e9 Mon Sep 17 00:00:00 2001
From: sjfhsjfh <sjfhsjfh@qq.com>
Date: Fri, 11 Apr 2025 23:08:33 +0800
Subject: [PATCH] feat: runtime rng feature

---
 Cargo.toml          |  7 +++++--
 src/helper/crypt.rs |  6 +++---
 src/lib.rs          |  2 +-
 src/random.rs       | 21 +++++++++++++++++++++
 4 files changed, 30 insertions(+), 6 deletions(-)
 create mode 100644 src/random.rs

diff --git a/Cargo.toml b/Cargo.toml
index a21d1c8e..5c7f7a0e 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -13,7 +13,7 @@ edition = "2021"
 
 [dependencies]
 aes = "0.8.4"
-ahash = "0.8.11"
+ahash = { version = "0.8.11", default-features = false, features = ["std"] }
 base64 = "0.22.1"
 byteorder = "1.5"
 cbc = "0.1.2"
@@ -21,12 +21,12 @@ cfb = "0.10.0"
 chrono = { version = "0.4.38", default-features = false, features = ["clock"] }
 encoding_rs = "0.8.35"
 fancy-regex = "0.14.0"
-getrandom = { version = "0.2.15" }
 hmac = "0.12.1"
 html_parser = "0.7.0"
 image = { version = "0.25.5", optional = true }
 lazy_static = "1.5.0"
 md-5 = "0.10.6"
+rand = { version = "0.9.0", default-features = false, features = ["small_rng"] }
 regex = "1.11.1"
 sha2 = "0.10.8"
 thin-vec = "0.2.13"
@@ -34,9 +34,12 @@ thousands = "0.2.0"
 quick-xml = { version = "0.37.1", features = ["serialize"] }
 zip = { version = "2.2.1", default-features = false, features = ["deflate"] }
 
+getrandom = { version = "0.2.15", optional = true }
+
 [lib]
 doctest = false
 
 [features]
 js = ["getrandom/js"]
+runtime-rng = ["getrandom"]
 default = ["image"]
diff --git a/src/helper/crypt.rs b/src/helper/crypt.rs
index 2e7847c9..90b4357f 100644
--- a/src/helper/crypt.rs
+++ b/src/helper/crypt.rs
@@ -480,21 +480,21 @@ fn hash(algorithm: &str, buffers: Vec<&[u8]>) -> Result<Vec<u8>, String> {
 #[inline]
 fn gen_random_16() -> Vec<u8> {
     let buf: &mut [u8] = &mut [0; 16];
-    getrandom::getrandom(buf);
+    crate::random::getrandom(buf);
     buf.to_vec()
 }
 
 #[inline]
 fn gen_random_32() -> Vec<u8> {
     let buf: &mut [u8] = &mut [0; 32];
-    getrandom::getrandom(buf);
+    crate::random::getrandom(buf);
     buf.to_vec()
 }
 
 #[inline]
 fn gen_random_64() -> Vec<u8> {
     let buf: &mut [u8] = &mut [0; 64];
-    getrandom::getrandom(buf);
+    crate::random::getrandom(buf);
     buf.to_vec()
 }
 
diff --git a/src/lib.rs b/src/lib.rs
index 4b391c84..35394854 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -134,7 +134,6 @@ extern crate base64;
 extern crate byteorder;
 extern crate cbc;
 extern crate cfb;
-extern crate getrandom;
 extern crate hmac;
 extern crate html_parser;
 extern crate sha2;
@@ -147,6 +146,7 @@ pub mod reader;
 pub mod structs;
 pub mod traits;
 pub mod writer;
+mod random;
 
 pub use self::structs::*;
 pub use self::traits::*;
diff --git a/src/random.rs b/src/random.rs
new file mode 100644
index 00000000..50eedb57
--- /dev/null
+++ b/src/random.rs
@@ -0,0 +1,21 @@
+pub(crate) fn getrandom(buf: &mut [u8]) -> Result<(), String> {
+    #[cfg(feature = "runtime-rng")]
+    {
+        extern crate getrandom;
+        match getrandom::getrandom(buf) {
+            Ok(_) => Ok(()),
+            Err(e) => Err(format!("getrandom error: {}", e)),
+        }
+    }
+    #[cfg(not(feature = "runtime-rng"))]
+    {
+        use rand::{RngCore, SeedableRng};
+        let seed = b"No Runtime RNG HERE!!!!!!!!!!111";
+        let len = buf.len();
+        let mut rng = rand::rngs::SmallRng::from_seed(*seed);
+        for byte in buf.iter_mut() {
+            *byte = rng.next_u32() as u8;
+        }
+        Ok(())
+    }
+}