ecies: drop randomness parameter from `PrivateKey.Decrypt` (#16374)

The parameter `rand` is unused in `PrivateKey.Decrypt`. Decryption in
the ECIES encryption scheme is deterministic, so randomness isn't
needed.

1 files changed, 3 insertions, 3 deletions

diff --git a/crypto/ecies/ecies.go b/crypto/ecies/ecies.go
index 2ed91c895..147418148 100644
--- a/crypto/ecies/ecies.go
+++ b/crypto/ecies/ecies.go
@@ -230,7 +230,7 @@ func symEncrypt(rand io.Reader, params *ECIESParams, key, m []byte) (ct []byte,
 
 // symDecrypt carries out CTR decryption using the block cipher specified in
 // the parameters
-func symDecrypt(rand io.Reader, params *ECIESParams, key, ct []byte) (m []byte, err error) {
+func symDecrypt(params *ECIESParams, key, ct []byte) (m []byte, err error) {
 	c, err := params.Cipher(key)
 	if err != nil {
 		return
@@ -292,7 +292,7 @@ func Encrypt(rand io.Reader, pub *PublicKey, m, s1, s2 []byte) (ct []byte, err e
 }
 
 // Decrypt decrypts an ECIES ciphertext.
-func (prv *PrivateKey) Decrypt(rand io.Reader, c, s1, s2 []byte) (m []byte, err error) {
+func (prv *PrivateKey) Decrypt(c, s1, s2 []byte) (m []byte, err error) {
 	if len(c) == 0 {
 		return nil, ErrInvalidMessage
 	}
@@ -361,6 +361,6 @@ func (prv *PrivateKey) Decrypt(rand io.Reader, c, s1, s2 []byte) (m []byte, err
 		return
 	}
 
-	m, err = symDecrypt(rand, params, Ke, c[mStart:mEnd])
+	m, err = symDecrypt(params, Ke, c[mStart:mEnd])
 	return
 }