rust/pv: Remove memeq function

The rust std lib already provides functionality to compare two slies.
Replace all `memeq` invocations with == and remove the `memeq` function.
As a side effect this eliminates some unsafe code in this crate.

Reviewed-by: Marc Hartmayer <mhartmay@linux.ibm.com>
Signed-off-by: Steffen Eiden <seiden@linux.ibm.com>
Signed-off-by: Jan Höppner <hoeppner@linux.ibm.com>

rust/pv/src/verify/helper.rs

@@ -3,7 +3,7 @@
 // Copyright IBM Corp. 2023
 
 use crate::error::bail_hkd_verify;
-use crate::misc::{memeq, read_crls};
+use crate::misc::read_crls;
 use crate::HkdVerifyErrorType::*;
 use crate::{Error, Result};
 use curl::easy::{Easy2, Handler, WriteError};
@@ -219,7 +219,7 @@ fn name_data_eq(entries: &X509NameRef, nid: Nid, rhs: &[u8]) -> bool {
     let mut it = entries.entries_by_nid(nid);
     match it.next() {
         None => false,
-        Some(entry) => memeq(entry.data().as_slice(), rhs),
+        Some(entry) => entry.data().as_slice() == rhs,
     }
 }
 
@@ -376,11 +376,12 @@ fn check_x509_name_equal(lhs: &X509NameRef, rhs: &X509NameRef) -> Result<()> {
     }
 
     for l in lhs.entries() {
-        let ldata = l.data().as_slice();
-
         // search for the matching value in the rhs names
         // found none? -> names are not equal
-        if !rhs.entries().any(|r| memeq(ldata, r.data().as_slice())) {
+        if !rhs
+            .entries()
+            .any(|r| l.data().as_slice() == r.data().as_slice())
+        {
             bail_hkd_verify!(IssuerMismatch);
         }
     }

rust/pv_core/src/lib.rs

@@ -26,7 +26,7 @@ pub use error::{Error, FileAccessErrorType, FileIoErrorType, Result};
 pub mod misc {
     pub use crate::utils::pv_guest_bit_set;
     pub use crate::utils::{create_file, open_file, read_exact_file, read_file, write_file};
-    pub use crate::utils::{memeq, parse_hex, to_u16, to_u32, try_parse_u128, try_parse_u64};
+    pub use crate::utils::{parse_hex, to_u16, to_u32, try_parse_u128, try_parse_u64};
     pub use crate::utils::{read, write};
     pub use crate::utils::{Flags, Lsb0Flags64, Msb0Flags64};
 }
@@ -65,7 +65,7 @@ pub mod request {
             if v.len() < Self::MAGIC.len() {
                 return false;
             }
-            crate::misc::memeq(&v[..Self::MAGIC.len()], &Self::MAGIC)
+            v[..Self::MAGIC.len()] == Self::MAGIC
         }
     }
 }

rust/pv_core/src/utils.rs

@@ -335,20 +335,6 @@ usize_to_ui! {
 #[doc = r"u16"]
 => u16, to_u16}
 
-/// Test if both slices contain the exact same bytes.
-///
-/// Do not use this to compare cryptographic values (i.e. hashes)
-pub fn memeq(lhs: &[u8], rhs: &[u8]) -> bool {
-    let size = lhs.len();
-
-    size == rhs.len()
-        && unsafe {
-            let l = lhs as *const _ as _;
-            let r = rhs as *const _ as _;
-            (l as usize) == (r as usize) || libc::memcmp(l, r, size) == 0
-        }
-}
-
 /// Converts the hexstring into a byte vector.
 ///
 /// Stops if the end or until a non hex chat is found
@@ -573,17 +559,4 @@ mod tests {
             try_parse_u128("00112233445566778899aabbccddeeff", "").unwrap()
         );
     }
-
-    #[test]
-    fn memeq() {
-        let a = [1, 2, 3, 4, 5, 6, 7, 8, 9, 0];
-        let b = [1, 2, 3, 4, 5, 6, 7, 8, 9, 1];
-        let c = [0, 0, 1, 2, 3, 4];
-
-        assert!(super::memeq(&a, &a));
-        assert!(super::memeq(&a, &a.clone()));
-        assert!(!super::memeq(&b, &a));
-        assert!(!super::memeq(&b, &c));
-        assert!(!super::memeq(&b, &[]));
-    }
 }