crypto/internal/mlkem768: remove crypto/rand.Read error checking

After #66821 crypto/rand.Read can't return an error.

Change-Id: I185063a25ef70986448f2a300e5578de17f6e61e
Reviewed-on: https://go-review.googlesource.com/c/go/+/621979
Auto-Submit: Filippo Valsorda <filippo@golang.org>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: Michael Knyszek <mknyszek@google.com>
Reviewed-by: Russ Cox <rsc@golang.org>
Reviewed-by: Daniel McCarney <daniel@binaryparadox.net>

diff --git a/src/crypto/internal/mlkem768/mlkem768.go b/src/crypto/internal/mlkem768/mlkem768.go
index 45f4b78056ad7e428e083d79ad6cab6cddc89f28..f152e7682ee9616042e079818c98129ef4431fc1 100644 (file)
--- a/src/crypto/internal/mlkem768/mlkem768.go
+++ b/src/crypto/internal/mlkem768/mlkem768.go
@@ -112,19 +112,15 @@ type decryptionKey struct {
 func GenerateKey() (*DecapsulationKey, error) {
        // The actual logic is in a separate function to outline this allocation.
        dk := &DecapsulationKey{}
-       return generateKey(dk)
+       return generateKey(dk), nil
 }
 
-func generateKey(dk *DecapsulationKey) (*DecapsulationKey, error) {
+func generateKey(dk *DecapsulationKey) *DecapsulationKey {
        var d [32]byte
-       if _, err := rand.Read(d[:]); err != nil {
-               return nil, errors.New("mlkem768: crypto/rand Read failed: " + err.Error())
-       }
+       rand.Read(d[:])
        var z [32]byte
-       if _, err := rand.Read(z[:]); err != nil {
-               return nil, errors.New("mlkem768: crypto/rand Read failed: " + err.Error())
-       }
-       return kemKeyGen(dk, &d, &z), nil
+       rand.Read(z[:])
+       return kemKeyGen(dk, &d, &z)
 }
 
 // NewKeyFromSeed deterministically generates a decapsulation key from a 64-byte
@@ -214,9 +210,7 @@ func encapsulate(cc *[CiphertextSize]byte, encapsulationKey []byte) (ciphertext,
                return nil, nil, errors.New("mlkem768: invalid encapsulation key length")
        }
        var m [messageSize]byte
-       if _, err := rand.Read(m[:]); err != nil {
-               return nil, nil, errors.New("mlkem768: crypto/rand Read failed: " + err.Error())
-       }
+       rand.Read(m[:])
        // Note that the modulus check (step 2 of the encapsulation key check from
        // FIPS 203, Section 7.2) is performed by polyByteDecode in parseEK.
        return kemEncaps(cc, encapsulationKey, &m)