Simplify hash implementation (#237)

* simplify hash implementations

* fix openssl 3

* fix AZL 3

Author: qmuntal

evp.go

@@ -48,29 +48,8 @@ func hashFuncHash(fn func() hash.Hash) (h hash.Hash, err error) {
 
 // hashToMD converts a hash.Hash implementation from this package to a GO_EVP_MD_PTR.
 func hashToMD(h hash.Hash) C.GO_EVP_MD_PTR {
-	var ch crypto.Hash
-	switch h.(type) {
-	case *sha1Hash, *sha1Marshal:
-		ch = crypto.SHA1
-	case *sha224Hash, *sha224Marshal:
-		ch = crypto.SHA224
-	case *sha256Hash, *sha256Marshal:
-		ch = crypto.SHA256
-	case *sha384Hash, *sha384Marshal:
-		ch = crypto.SHA384
-	case *sha512Hash, *sha512Marshal:
-		ch = crypto.SHA512
-	case *sha3_224Hash:
-		ch = crypto.SHA3_224
-	case *sha3_256Hash:
-		ch = crypto.SHA3_256
-	case *sha3_384Hash:
-		ch = crypto.SHA3_384
-	case *sha3_512Hash:
-		ch = crypto.SHA3_512
-	}
-	if ch != 0 {
-		return cryptoHashToMD(ch)
+	if h, ok := h.(*evpHash); ok {
+		return h.alg.md
 	}
 	return nil
 }
@@ -89,78 +68,109 @@ func hashFuncToMD(fn func() hash.Hash) (C.GO_EVP_MD_PTR, error) {
 	return md, nil
 }
 
-// cryptoHashToMD converts a crypto.Hash to a EVP_MD.
-func cryptoHashToMD(ch crypto.Hash) C.GO_EVP_MD_PTR {
+type hashAlgorithm struct {
+	md             C.GO_EVP_MD_PTR
+	ch             crypto.Hash
+	size           int
+	blockSize      int
+	marshallable   bool
+	magic          string
+	marshalledSize int
+}
+
+// loadHash converts a crypto.Hash to a EVP_MD.
+func loadHash(ch crypto.Hash) *hashAlgorithm {
 	if v, ok := cacheMD.Load(ch); ok {
-		return v.(C.GO_EVP_MD_PTR)
+		return v.(*hashAlgorithm)
 	}
-	var md C.GO_EVP_MD_PTR
+
+	var hash hashAlgorithm
 	switch ch {
 	case crypto.RIPEMD160:
-		md = C.go_openssl_EVP_ripemd160()
+		hash.md = C.go_openssl_EVP_ripemd160()
 	case crypto.MD4:
-		md = C.go_openssl_EVP_md4()
+		hash.md = C.go_openssl_EVP_md4()
 	case crypto.MD5:
-		md = C.go_openssl_EVP_md5()
+		hash.md = C.go_openssl_EVP_md5()
+		hash.magic = md5Magic
+		hash.marshalledSize = md5MarshaledSize
 	case crypto.MD5SHA1:
 		if vMajor == 1 && vMinor == 0 {
-			md = C.go_openssl_EVP_md5_sha1_backport()
+			hash.md = C.go_openssl_EVP_md5_sha1_backport()
 		} else {
-			md = C.go_openssl_EVP_md5_sha1()
+			hash.md = C.go_openssl_EVP_md5_sha1()
 		}
 	case crypto.SHA1:
-		md = C.go_openssl_EVP_sha1()
+		hash.md = C.go_openssl_EVP_sha1()
+		hash.magic = sha1Magic
+		hash.marshalledSize = sha1MarshaledSize
 	case crypto.SHA224:
-		md = C.go_openssl_EVP_sha224()
+		hash.md = C.go_openssl_EVP_sha224()
+		hash.magic = magic224
+		hash.marshalledSize = marshaledSize256
 	case crypto.SHA256:
-		md = C.go_openssl_EVP_sha256()
+		hash.md = C.go_openssl_EVP_sha256()
+		hash.magic = magic256
+		hash.marshalledSize = marshaledSize256
 	case crypto.SHA384:
-		md = C.go_openssl_EVP_sha384()
+		hash.md = C.go_openssl_EVP_sha384()
+		hash.magic = magic384
+		hash.marshalledSize = marshaledSize512
 	case crypto.SHA512:
-		md = C.go_openssl_EVP_sha512()
+		hash.md = C.go_openssl_EVP_sha512()
+		hash.magic = magic512
+		hash.marshalledSize = marshaledSize512
 	case crypto.SHA512_224:
 		if versionAtOrAbove(1, 1, 1) {
-			md = C.go_openssl_EVP_sha512_224()
+			hash.md = C.go_openssl_EVP_sha512_224()
+			hash.magic = magic512_224
+			hash.marshalledSize = marshaledSize512
 		}
 	case crypto.SHA512_256:
 		if versionAtOrAbove(1, 1, 1) {
-			md = C.go_openssl_EVP_sha512_256()
+			hash.md = C.go_openssl_EVP_sha512_256()
+			hash.magic = magic512_256
+			hash.marshalledSize = marshaledSize512
 		}
 	case crypto.SHA3_224:
 		if versionAtOrAbove(1, 1, 1) {
-			md = C.go_openssl_EVP_sha3_224()
+			hash.md = C.go_openssl_EVP_sha3_224()
 		}
 	case crypto.SHA3_256:
 		if versionAtOrAbove(1, 1, 1) {
-			md = C.go_openssl_EVP_sha3_256()
+			hash.md = C.go_openssl_EVP_sha3_256()
 		}
 	case crypto.SHA3_384:
 		if versionAtOrAbove(1, 1, 1) {
-			md = C.go_openssl_EVP_sha3_384()
+			hash.md = C.go_openssl_EVP_sha3_384()
 		}
 	case crypto.SHA3_512:
 		if versionAtOrAbove(1, 1, 1) {
-			md = C.go_openssl_EVP_sha3_512()
+			hash.md = C.go_openssl_EVP_sha3_512()
 		}
 	}
-	if md == nil {
-		cacheMD.Store(ch, nil)
+	if hash.md == nil {
+		cacheMD.Store(ch, (*hashAlgorithm)(nil))
 		return nil
 	}
+	hash.ch = ch
+	hash.size = int(C.go_openssl_EVP_MD_get_size(hash.md))
+	hash.blockSize = int(C.go_openssl_EVP_MD_get_block_size(hash.md))
 	if vMajor == 3 {
 		// On OpenSSL 3, directly operating on a EVP_MD object
 		// not created by EVP_MD_fetch has negative performance
 		// implications, as digest operations will have
 		// to fetch it on every call. Better to just fetch it once here.
-		md1 := C.go_openssl_EVP_MD_fetch(nil, C.go_openssl_EVP_MD_get0_name(md), nil)
+		md := C.go_openssl_EVP_MD_fetch(nil, C.go_openssl_EVP_MD_get0_name(hash.md), nil)
 		// Don't overwrite md in case it can't be fetched, as the md may still be used
 		// outside of EVP_MD_CTX, for example to sign and verify RSA signatures.
-		if md1 != nil {
-			md = md1
+		if md != nil {
+			hash.md = md
 		}
 	}
-	cacheMD.Store(ch, md)
-	return md
+	hash.marshallable = hash.magic != "" && isHashMarshallable(hash.md)
+	cacheMD.Store(ch, &hash)
+	return &hash
 }
 
 // generateEVPPKey generates a new EVP_PKEY with the given id and properties.
@@ -302,11 +312,11 @@ func setupEVP(withKey withKeyFunc, padding C.int,
 			}
 		}
 	case C.GO_RSA_PKCS1_PSS_PADDING:
-		md := cryptoHashToMD(ch)
-		if md == nil {
+		alg := loadHash(ch)
+		if alg == nil {
 			return nil, errors.New("crypto/rsa: unsupported hash function")
 		}
-		if C.go_openssl_EVP_PKEY_CTX_ctrl(ctx, C.GO_EVP_PKEY_RSA, -1, C.GO_EVP_PKEY_CTRL_MD, 0, unsafe.Pointer(md)) != 1 {
+		if C.go_openssl_EVP_PKEY_CTX_ctrl(ctx, C.GO_EVP_PKEY_RSA, -1, C.GO_EVP_PKEY_CTRL_MD, 0, unsafe.Pointer(alg.md)) != 1 {
 			return nil, newOpenSSLError("EVP_PKEY_CTX_ctrl failed")
 		}
 		// setPadding must happen after setting EVP_PKEY_CTRL_MD.
@@ -322,11 +332,11 @@ func setupEVP(withKey withKeyFunc, padding C.int,
 	case C.GO_RSA_PKCS1_PADDING:
 		if ch != 0 {
 			// We support unhashed messages.
-			md := cryptoHashToMD(ch)
-			if md == nil {
+			alg := loadHash(ch)
+			if alg == nil {
 				return nil, errors.New("crypto/rsa: unsupported hash function")
 			}
-			if C.go_openssl_EVP_PKEY_CTX_ctrl(ctx, -1, -1, C.GO_EVP_PKEY_CTRL_MD, 0, unsafe.Pointer(md)) != 1 {
+			if C.go_openssl_EVP_PKEY_CTX_ctrl(ctx, -1, -1, C.GO_EVP_PKEY_CTRL_MD, 0, unsafe.Pointer(alg.md)) != 1 {
 				return nil, newOpenSSLError("EVP_PKEY_CTX_ctrl failed")
 			}
 			if err := setPadding(); err != nil {
@@ -441,8 +451,8 @@ func evpVerify(withKey withKeyFunc, padding C.int, saltLen C.int, h crypto.Hash,
 }
 
 func evpHashSign(withKey withKeyFunc, h crypto.Hash, msg []byte) ([]byte, error) {
-	md := cryptoHashToMD(h)
-	if md == nil {
+	alg := loadHash(h)
+	if alg == nil {
 		return nil, errors.New("unsupported hash function: " + strconv.Itoa(int(h)))
 	}
 	var out []byte
@@ -453,7 +463,7 @@ func evpHashSign(withKey withKeyFunc, h crypto.Hash, msg []byte) ([]byte, error)
 	}
 	defer C.go_openssl_EVP_MD_CTX_free(ctx)
 	if withKey(func(key C.GO_EVP_PKEY_PTR) C.int {
-		return C.go_openssl_EVP_DigestSignInit(ctx, nil, md, nil, key)
+		return C.go_openssl_EVP_DigestSignInit(ctx, nil, alg.md, nil, key)
 	}) != 1 {
 		return nil, newOpenSSLError("EVP_DigestSignInit failed")
 	}
@@ -473,8 +483,8 @@ func evpHashSign(withKey withKeyFunc, h crypto.Hash, msg []byte) ([]byte, error)
 }
 
 func evpHashVerify(withKey withKeyFunc, h crypto.Hash, msg, sig []byte) error {
-	md := cryptoHashToMD(h)
-	if md == nil {
+	alg := loadHash(h)
+	if alg == nil {
 		return errors.New("unsupported hash function: " + strconv.Itoa(int(h)))
 	}
 	ctx := C.go_openssl_EVP_MD_CTX_new()
@@ -483,7 +493,7 @@ func evpHashVerify(withKey withKeyFunc, h crypto.Hash, msg, sig []byte) error {
 	}
 	defer C.go_openssl_EVP_MD_CTX_free(ctx)
 	if withKey(func(key C.GO_EVP_PKEY_PTR) C.int {
-		return C.go_openssl_EVP_DigestVerifyInit(ctx, nil, md, nil, key)
+		return C.go_openssl_EVP_DigestVerifyInit(ctx, nil, alg.md, nil, key)
 	}) != 1 {
 		return newOpenSSLError("EVP_DigestVerifyInit failed")
 	}