Unsafe i32 to usize conversion from network data

lib/rs/src/lib.rs

@@ -91,3 +91,46 @@ pub type Result<T> = std::result::Result<T, self::Error>;
 // Re-export ordered-float, since it is used by the generator
 // FIXME: check the guidance around type reexports
 pub use ordered_float::OrderedFloat;
+
+use std::io::{Error as IoErr, ErrorKind as IoErrKind};
+use std::ops::RangeBounds;
+
+/// A trait similar to try-from but with additional checks
+pub trait TryIntoRange<T>: TryInto<T> {
+    type ErrTy;
+
+    fn try_into_range(self, between: impl RangeBounds<Self>)
+        -> std::result::Result<T, Self::ErrTy>;
+}
+
+impl TryIntoRange<usize> for i32 {
+    type ErrTy = IoErr;
+
+    fn try_into_range(
+        self,
+        between: impl RangeBounds<Self>,
+    ) -> std::result::Result<usize, Self::ErrTy> {
+        if between.contains(&self) {
+            self.try_into()
+                .map_err(|_| IoErr::from(IoErrKind::InvalidData))
+        } else {
+            Err(IoErr::from(IoErrKind::InvalidData))
+        }
+    }
+}
+
+impl TryIntoRange<usize> for u32 {
+    type ErrTy = IoErr;
+
+    fn try_into_range(
+        self,
+        between: impl RangeBounds<Self>,
+    ) -> std::result::Result<usize, Self::ErrTy> {
+        if between.contains(&self) {
+            self.try_into()
+                .map_err(|_| IoErr::from(IoErrKind::InvalidData))
+        } else {
+            Err(IoErr::from(IoErrKind::InvalidData))
+        }
+    }
+}

lib/rs/src/protocol/binary.rs

@@ -24,6 +24,7 @@ use super::{
 };
 use super::{TOutputProtocol, TOutputProtocolFactory, TSetIdentifier, TStructIdentifier, TType};
 use crate::transport::{TReadTransport, TWriteTransport};
+use crate::TryIntoRange;
 use crate::{ProtocolError, ProtocolErrorKind};
 
 const BINARY_PROTOCOL_VERSION_1: u32 = 0x8001_0000;
@@ -112,7 +113,7 @@ where
                 // in the non-strict version the first message field
                 // is the message name. strings (byte arrays) are length-prefixed,
                 // so we've just read the length in the first 4 bytes
-                let name_size = BigEndian::read_i32(&first_bytes) as usize;
+                let name_size = BigEndian::read_i32(&first_bytes).try_into_range(0..=i32::MAX)?;
                 let mut name_buf: Vec<u8> = vec![0; name_size];
                 self.transport.read_exact(&mut name_buf)?;
                 let name = String::from_utf8(name_buf)?;
@@ -154,7 +155,10 @@ where
     }
 
     fn read_bytes(&mut self) -> crate::Result<Vec<u8>> {
-        let num_bytes = self.transport.read_i32::<BigEndian>()? as usize;
+        let num_bytes = self
+            .transport
+            .read_i32::<BigEndian>()?
+            .try_into_range(0..=i32::MAX)?;
         let mut buf = vec![0u8; num_bytes];
         self.transport
             .read_exact(&mut buf)

lib/rs/src/transport/framed.rs

@@ -15,13 +15,13 @@
 // specific language governing permissions and limitations
 // under the License.
 
+use super::{TReadTransport, TReadTransportFactory, TWriteTransport, TWriteTransportFactory};
+use crate::TryIntoRange;
 use byteorder::{BigEndian, ReadBytesExt, WriteBytesExt};
 use std::cmp;
 use std::io;
 use std::io::{Read, Write};
 
-use super::{TReadTransport, TReadTransportFactory, TWriteTransport, TWriteTransportFactory};
-
 /// Default capacity of the read buffer in bytes.
 const READ_CAPACITY: usize = 4096;
 
@@ -91,13 +91,16 @@ where
 {
     fn read(&mut self, b: &mut [u8]) -> io::Result<usize> {
         if self.cap - self.pos == 0 {
-            let message_size = self.chan.read_i32::<BigEndian>()? as usize;
+            let message_size = self
+                .chan
+                .read_i32::<BigEndian>()?
+                .try_into_range(0..=i32::MAX)?; // Range should be smaller?
 
             let buf_capacity = cmp::max(message_size, READ_CAPACITY);
             self.buf.resize(buf_capacity, 0);
 
             self.chan.read_exact(&mut self.buf[..message_size])?;
-            self.cap = message_size as usize;
+            self.cap = message_size;
             self.pos = 0;
         }