From 6b2a1d5242503d6d4ad89d40c752368190817f84 Mon Sep 17 00:00:00 2001
From: Andrei Burdulescu <andrei.burdulescu@pm.me>
Date: Sun, 10 Dec 2023 13:13:30 +0200
Subject: [PATCH] Use *os.File instead of io.Reader/io.Writer

---
 internal/aes/cbc.go                 | 20 +++++++----------
 internal/aes/cmac.go                | 32 +++++++++++----------------
 internal/aes/ecb.go                 | 20 +++++++----------
 internal/aes/gcm.go                 | 20 +++++++----------
 internal/encoding/rsa/der2pem.go    | 20 +++++++----------
 internal/encoding/rsa/pem2der.go    | 22 ++++++++-----------
 internal/encoding/rsa/priv2pub.go   | 20 +++++++----------
 internal/hash/sha.go                | 34 +++++++++++++----------------
 internal/kdf/pbkdf2.go              | 10 ++++-----
 internal/kem/rsa/cmd/kem.go         | 20 +++++++----------
 internal/keygen/aes.go              | 13 +++++------
 internal/keygen/ed25519.go          | 13 +++++------
 internal/keygen/rsa.go              | 11 ++++------
 internal/keywrap/aes/cmd/keywrap.go | 20 +++++++----------
 14 files changed, 111 insertions(+), 164 deletions(-)

diff --git a/internal/aes/cbc.go b/internal/aes/cbc.go
index 34911ac..4811204 100644
--- a/internal/aes/cbc.go
+++ b/internal/aes/cbc.go
@@ -74,32 +74,28 @@ Options:
 		return err
 	}
 
-	var r io.Reader
-	if *fInput == "" {
-		r = os.Stdin
-	} else {
+	in := os.Stdin
+	if *fInput != "" {
 		f, err := os.Open(*fInput)
 		if err != nil {
 			return err
 		}
 		defer f.Close()
-		r = f
+		in = f
 	}
 
-	var w io.Writer
-	if *fOutput == "" {
-		w = os.Stdout
-	} else {
+	out := os.Stdout
+	if *fOutput != "" {
 		f, err := os.Create(*fOutput)
 		if err != nil {
 			return err
 		}
 		defer f.Close()
-		w = f
+		out = f
 	}
 
 	var input bytes.Buffer
-	if _, err := io.Copy(&input, r); err != nil {
+	if _, err := io.Copy(&input, in); err != nil {
 		return err
 	}
 
@@ -118,7 +114,7 @@ Options:
 
 	output := cbcProcessBlocks(c, input.Bytes())
 
-	if _, err := io.Copy(w, bytes.NewBuffer(output)); err != nil {
+	if _, err := io.Copy(out, bytes.NewBuffer(output)); err != nil {
 		return err
 	}
 
diff --git a/internal/aes/cmac.go b/internal/aes/cmac.go
index 7807112..8382363 100644
--- a/internal/aes/cmac.go
+++ b/internal/aes/cmac.go
@@ -64,32 +64,28 @@ Options:
 		key = b
 	}
 
-	var r io.Reader
-	if *fInput == "" {
-		r = os.Stdin
-	} else {
+	in := os.Stdin
+	if *fInput != "" {
 		f, err := os.Open(*fInput)
 		if err != nil {
 			return err
 		}
 		defer f.Close()
-		r = f
+		in = f
 	}
 
-	var w io.Writer
-	if *fOutput == "" {
-		w = os.Stdout
-	} else {
+	out := os.Stdout
+	if *fOutput != "" {
 		f, err := os.Create(*fOutput)
 		if err != nil {
 			return err
 		}
 		defer f.Close()
-		w = f
+		out = f
 	}
 
 	var input bytes.Buffer
-	if _, err := io.Copy(&input, r); err != nil {
+	if _, err := io.Copy(&input, in); err != nil {
 		return err
 	}
 
@@ -104,11 +100,11 @@ Options:
 	}
 
 	if *fBin {
-		if _, err := io.Copy(w, bytes.NewBuffer(output)); err != nil {
+		if _, err := io.Copy(out, bytes.NewBuffer(output)); err != nil {
 			return err
 		}
 	} else {
-		fmt.Fprintln(w, hex.EncodeToString(output))
+		fmt.Fprintln(out, hex.EncodeToString(output))
 	}
 
 	return nil
@@ -171,20 +167,18 @@ Options:
 		return err
 	}
 
-	var r io.Reader
-	if *fInput == "" {
-		r = os.Stdin
-	} else {
+	in := os.Stdin
+	if *fInput != "" {
 		f, err := os.Open(*fInput)
 		if err != nil {
 			return err
 		}
 		defer f.Close()
-		r = f
+		in = f
 	}
 
 	var input bytes.Buffer
-	if _, err := io.Copy(&input, r); err != nil {
+	if _, err := io.Copy(&input, in); err != nil {
 		return err
 	}
 
diff --git a/internal/aes/ecb.go b/internal/aes/ecb.go
index 1e55365..850f6aa 100644
--- a/internal/aes/ecb.go
+++ b/internal/aes/ecb.go
@@ -63,32 +63,28 @@ Options:
 		key = b
 	}
 
-	var r io.Reader
-	if *fInput == "" {
-		r = os.Stdin
-	} else {
+	in := os.Stdin
+	if *fInput != "" {
 		f, err := os.Open(*fInput)
 		if err != nil {
 			return err
 		}
 		defer f.Close()
-		r = f
+		in = f
 	}
 
-	var w io.Writer
-	if *fOutput == "" {
-		w = os.Stdout
-	} else {
+	out := os.Stdout
+	if *fOutput != "" {
 		f, err := os.Create(*fOutput)
 		if err != nil {
 			return err
 		}
 		defer f.Close()
-		w = f
+		out = f
 	}
 
 	var input bytes.Buffer
-	if _, err := io.Copy(&input, r); err != nil {
+	if _, err := io.Copy(&input, in); err != nil {
 		return err
 	}
 
@@ -106,7 +102,7 @@ Options:
 		return err
 	}
 
-	if _, err := io.Copy(w, bytes.NewBuffer(output)); err != nil {
+	if _, err := io.Copy(out, bytes.NewBuffer(output)); err != nil {
 		return err
 	}
 
diff --git a/internal/aes/gcm.go b/internal/aes/gcm.go
index 20365df..c10bd0c 100644
--- a/internal/aes/gcm.go
+++ b/internal/aes/gcm.go
@@ -85,32 +85,28 @@ Options:
 		aad = b
 	}
 
-	var r io.Reader
-	if *fInput == "" {
-		r = os.Stdin
-	} else {
+	in := os.Stdin
+	if *fInput != "" {
 		f, err := os.Open(*fInput)
 		if err != nil {
 			return err
 		}
 		defer f.Close()
-		r = f
+		in = f
 	}
 
-	var w io.Writer
-	if *fOutput == "" {
-		w = os.Stdout
-	} else {
+	out := os.Stdout
+	if *fOutput != "" {
 		f, err := os.Create(*fOutput)
 		if err != nil {
 			return err
 		}
 		defer f.Close()
-		w = f
+		out = f
 	}
 
 	var input bytes.Buffer
-	if _, err := io.Copy(&input, r); err != nil {
+	if _, err := io.Copy(&input, in); err != nil {
 		return err
 	}
 
@@ -127,7 +123,7 @@ Options:
 		return err
 	}
 
-	if _, err := io.Copy(w, bytes.NewBuffer(output)); err != nil {
+	if _, err := io.Copy(out, bytes.NewBuffer(output)); err != nil {
 		return err
 	}
 
diff --git a/internal/encoding/rsa/der2pem.go b/internal/encoding/rsa/der2pem.go
index f4b1179..831eb93 100644
--- a/internal/encoding/rsa/der2pem.go
+++ b/internal/encoding/rsa/der2pem.go
@@ -36,32 +36,28 @@ Options:
 		return err
 	}
 
-	var r io.Reader
-	if *fInput == "" {
-		r = os.Stdin
-	} else {
+	in := os.Stdin
+	if *fInput != "" {
 		f, err := os.Open(*fInput)
 		if err != nil {
 			return err
 		}
 		defer f.Close()
-		r = f
+		in = f
 	}
 
-	var w io.Writer
-	if *fOutput == "" {
-		w = os.Stdout
-	} else {
+	out := os.Stdout
+	if *fOutput != "" {
 		f, err := os.Create(*fOutput)
 		if err != nil {
 			return err
 		}
 		defer f.Close()
-		w = f
+		out = f
 	}
 
 	var input bytes.Buffer
-	if _, err := io.Copy(&input, r); err != nil {
+	if _, err := io.Copy(&input, in); err != nil {
 		return err
 	}
 
@@ -80,7 +76,7 @@ Options:
 		Type:  blockType,
 		Bytes: input.Bytes(),
 	}
-	if err := pem.Encode(w, block); err != nil {
+	if err := pem.Encode(out, block); err != nil {
 		return err
 	}
 
diff --git a/internal/encoding/rsa/pem2der.go b/internal/encoding/rsa/pem2der.go
index 8a06d54..0000feb 100644
--- a/internal/encoding/rsa/pem2der.go
+++ b/internal/encoding/rsa/pem2der.go
@@ -34,32 +34,28 @@ Options:
 		return err
 	}
 
-	var r io.Reader
-	if *fInput == "" {
-		r = os.Stdin
-	} else {
+	in := os.Stdin
+	if *fInput != "" {
 		f, err := os.Open(*fInput)
 		if err != nil {
 			return err
 		}
 		defer f.Close()
-		r = f
+		in = f
 	}
 
-	var w io.Writer
-	if *fOutput == "" {
-		w = os.Stdout
-	} else {
+	out := os.Stdout
+	if *fOutput != "" {
 		f, err := os.Create(*fOutput)
 		if err != nil {
 			return err
 		}
 		defer f.Close()
-		w = f
+		out = f
 	}
 
 	var input bytes.Buffer
-	if _, err := io.Copy(&input, r); err != nil {
+	if _, err := io.Copy(&input, in); err != nil {
 		return err
 	}
 
@@ -69,11 +65,11 @@ Options:
 	}
 
 	if *fPrintBin {
-		if _, err := io.Copy(w, bytes.NewBuffer(block.Bytes)); err != nil {
+		if _, err := io.Copy(out, bytes.NewBuffer(block.Bytes)); err != nil {
 			return err
 		}
 	} else {
-		fmt.Fprintln(w, hex.EncodeToString(block.Bytes))
+		fmt.Fprintln(out, hex.EncodeToString(block.Bytes))
 	}
 
 	return nil
diff --git a/internal/encoding/rsa/priv2pub.go b/internal/encoding/rsa/priv2pub.go
index a26ee8d..5b24566 100644
--- a/internal/encoding/rsa/priv2pub.go
+++ b/internal/encoding/rsa/priv2pub.go
@@ -34,32 +34,28 @@ Options:
 		return err
 	}
 
-	var r io.Reader
-	if *fInput == "" {
-		r = os.Stdin
-	} else {
+	in := os.Stdin
+	if *fInput != "" {
 		f, err := os.Open(*fInput)
 		if err != nil {
 			return err
 		}
 		defer f.Close()
-		r = f
+		in = f
 	}
 
-	var w io.Writer
-	if *fOutput == "" {
-		w = os.Stdout
-	} else {
+	out := os.Stdout
+	if *fOutput != "" {
 		f, err := os.Create(*fOutput)
 		if err != nil {
 			return err
 		}
 		defer f.Close()
-		w = f
+		out = f
 	}
 
 	var input bytes.Buffer
-	if _, err := io.Copy(&input, r); err != nil {
+	if _, err := io.Copy(&input, in); err != nil {
 		return err
 	}
 
@@ -75,7 +71,7 @@ Options:
 		Bytes: x509.MarshalPKCS1PublicKey(&pubKey),
 	}
 
-	if err := pem.Encode(w, pubKeyBlock); err != nil {
+	if err := pem.Encode(out, pubKeyBlock); err != nil {
 		return err
 	}
 
diff --git a/internal/hash/sha.go b/internal/hash/sha.go
index 1996441..a4b50c4 100644
--- a/internal/hash/sha.go
+++ b/internal/hash/sha.go
@@ -40,50 +40,46 @@ Options:
 		return errors.New("hash alg not specified, use -alg")
 	}
 
-	hashFunc, err := common.HashFuncFrom(*fAlg)
-	if err != nil {
-		fset.Usage()
-		return err
-	}
-
-	var r io.Reader
-	if *fInput == "" {
-		r = os.Stdin
-	} else {
+	in := os.Stdin
+	if *fInput != "" {
 		f, err := os.Open(*fInput)
 		if err != nil {
 			return err
 		}
 		defer f.Close()
-		r = f
+		in = f
 	}
 
-	var w io.Writer
-	if *fOutput == "" {
-		w = os.Stdout
-	} else {
+	out := os.Stdout
+	if *fOutput != "" {
 		f, err := os.Create(*fOutput)
 		if err != nil {
 			return err
 		}
 		defer f.Close()
-		w = f
+		out = f
+	}
+
+	hashFunc, err := common.HashFuncFrom(*fAlg)
+	if err != nil {
+		fset.Usage()
+		return err
 	}
 
 	h := hashFunc()
 
-	if _, err := io.Copy(h, r); err != nil {
+	if _, err := io.Copy(h, in); err != nil {
 		return err
 	}
 
 	digest := h.Sum(nil)
 
 	if *fBin {
-		if _, err := w.Write(digest); err != nil {
+		if _, err := out.Write(digest); err != nil {
 			return err
 		}
 	} else {
-		fmt.Fprintln(w, hex.EncodeToString(digest))
+		fmt.Fprintln(out, hex.EncodeToString(digest))
 	}
 
 	return nil
diff --git a/internal/kdf/pbkdf2.go b/internal/kdf/pbkdf2.go
index ebd9630..26bf8b9 100644
--- a/internal/kdf/pbkdf2.go
+++ b/internal/kdf/pbkdf2.go
@@ -102,21 +102,19 @@ Options:
 		salt = b
 	}
 
-	var w io.Writer
-	if *fOutput == "" {
-		w = os.Stdout
-	} else {
+	out := os.Stdout
+	if *fOutput != "" {
 		f, err := os.Create(*fOutput)
 		if err != nil {
 			return err
 		}
 		defer f.Close()
-		w = f
+		out = f
 	}
 
 	output := pbkdf2.Key(key, salt, *fIter, *fLen, hashFunc)
 
-	if _, err := io.Copy(w, bytes.NewBuffer(output)); err != nil {
+	if _, err := io.Copy(out, bytes.NewBuffer(output)); err != nil {
 		return err
 	}
 
diff --git a/internal/kem/rsa/cmd/kem.go b/internal/kem/rsa/cmd/kem.go
index ce2e43b..48cdee0 100644
--- a/internal/kem/rsa/cmd/kem.go
+++ b/internal/kem/rsa/cmd/kem.go
@@ -93,32 +93,28 @@ Options:
 		HashFunc: kdfHashFunc,
 	}
 
-	var r io.Reader
-	if *fInput == "" {
-		r = os.Stdin
-	} else {
+	in := os.Stdin
+	if *fInput != "" {
 		f, err := os.Open(*fInput)
 		if err != nil {
 			return err
 		}
 		defer f.Close()
-		r = f
+		in = f
 	}
 
-	var w io.Writer
-	if *fOutput == "" {
-		w = os.Stdout
-	} else {
+	out := os.Stdout
+	if *fOutput != "" {
 		f, err := os.Create(*fOutput)
 		if err != nil {
 			return err
 		}
 		defer f.Close()
-		w = f
+		out = f
 	}
 
 	var input bytes.Buffer
-	if _, err := io.Copy(&input, r); err != nil {
+	if _, err := io.Copy(&input, in); err != nil {
 		return err
 	}
 
@@ -135,7 +131,7 @@ Options:
 		return err
 	}
 
-	if _, err := io.Copy(w, bytes.NewBuffer(output)); err != nil {
+	if _, err := io.Copy(out, bytes.NewBuffer(output)); err != nil {
 		return err
 	}
 
diff --git a/internal/keygen/aes.go b/internal/keygen/aes.go
index 966ed24..9b81aa8 100644
--- a/internal/keygen/aes.go
+++ b/internal/keygen/aes.go
@@ -6,7 +6,6 @@ import (
 	"errors"
 	"flag"
 	"fmt"
-	"io"
 	"os"
 	"strconv"
 )
@@ -49,16 +48,14 @@ Options:
 	}
 	numBits /= 8
 
-	var w io.Writer
-	if *fOutput == "" {
-		w = os.Stdout
-	} else {
+	out := os.Stdout
+	if *fOutput != "" {
 		f, err := os.Create(*fOutput)
 		if err != nil {
 			return err
 		}
 		defer f.Close()
-		w = f
+		out = f
 	}
 
 	output := make([]byte, numBits)
@@ -67,11 +64,11 @@ Options:
 	}
 
 	if *fBin {
-		if _, err := w.Write(output); err != nil {
+		if _, err := out.Write(output); err != nil {
 			return err
 		}
 	} else {
-		fmt.Fprintln(w, hex.EncodeToString(output))
+		fmt.Fprintln(out, hex.EncodeToString(output))
 	}
 
 	return nil
diff --git a/internal/keygen/ed25519.go b/internal/keygen/ed25519.go
index cc55636..965a943 100644
--- a/internal/keygen/ed25519.go
+++ b/internal/keygen/ed25519.go
@@ -5,7 +5,6 @@ import (
 	"encoding/hex"
 	"flag"
 	"fmt"
-	"io"
 	"os"
 )
 
@@ -30,16 +29,14 @@ Options:
 		return err
 	}
 
-	var w io.Writer
-	if *fOutput == "" {
-		w = os.Stdout
-	} else {
+	out := os.Stdout
+	if *fOutput != "" {
 		f, err := os.Create(*fOutput)
 		if err != nil {
 			return err
 		}
 		defer f.Close()
-		w = f
+		out = f
 	}
 
 	key, _, err := ed25519.GenerateKey(nil)
@@ -48,11 +45,11 @@ Options:
 	}
 
 	if *fBin {
-		if _, err := w.Write(key); err != nil {
+		if _, err := out.Write(key); err != nil {
 			return err
 		}
 	} else {
-		fmt.Fprintln(w, hex.EncodeToString(key))
+		fmt.Fprintln(out, hex.EncodeToString(key))
 	}
 
 	return nil
diff --git a/internal/keygen/rsa.go b/internal/keygen/rsa.go
index dd58837..391defc 100644
--- a/internal/keygen/rsa.go
+++ b/internal/keygen/rsa.go
@@ -8,7 +8,6 @@ import (
 	"errors"
 	"flag"
 	"fmt"
-	"io"
 	"os"
 	"strconv"
 )
@@ -49,16 +48,14 @@ Options:
 		return errors.New("invalid num bits requested")
 	}
 
-	var w io.Writer
-	if *fOutput == "" {
-		w = os.Stdout
-	} else {
+	out := os.Stdout
+	if *fOutput != "" {
 		f, err := os.Create(*fOutput)
 		if err != nil {
 			return err
 		}
 		defer f.Close()
-		w = f
+		out = f
 	}
 
 	key, err := rsa.GenerateKey(rand.Reader, numBits)
@@ -70,7 +67,7 @@ Options:
 		Type:  "RSA PRIVATE KEY",
 		Bytes: x509.MarshalPKCS1PrivateKey(key),
 	}
-	if err := pem.Encode(w, block); err != nil {
+	if err := pem.Encode(out, block); err != nil {
 		return err
 	}
 
diff --git a/internal/keywrap/aes/cmd/keywrap.go b/internal/keywrap/aes/cmd/keywrap.go
index 394524c..93634a4 100644
--- a/internal/keywrap/aes/cmd/keywrap.go
+++ b/internal/keywrap/aes/cmd/keywrap.go
@@ -63,32 +63,28 @@ Options:
 		key = b
 	}
 
-	var r io.Reader
-	if *fInput == "" {
-		r = os.Stdin
-	} else {
+	in := os.Stdin
+	if *fInput != "" {
 		f, err := os.Open(*fInput)
 		if err != nil {
 			return err
 		}
 		defer f.Close()
-		r = f
+		in = f
 	}
 
-	var w io.Writer
-	if *fOutput == "" {
-		w = os.Stdout
-	} else {
+	out := os.Stdout
+	if *fOutput != "" {
 		f, err := os.Create(*fOutput)
 		if err != nil {
 			return err
 		}
 		defer f.Close()
-		w = f
+		out = f
 	}
 
 	var input bytes.Buffer
-	if _, err := io.Copy(&input, r); err != nil {
+	if _, err := io.Copy(&input, in); err != nil {
 		return err
 	}
 
@@ -106,7 +102,7 @@ Options:
 		return err
 	}
 
-	if _, err := io.Copy(w, bytes.NewBuffer(output)); err != nil {
+	if _, err := io.Copy(out, bytes.NewBuffer(output)); err != nil {
 		return err
 	}