Add ahash package.

ahash/ahash.go

@@ -0,0 +1,258 @@
+// Package ahash provides support for hashing data with a selectable
+//  hash function.
+package ahash
+
+import (
+	"crypto/md5"
+	"crypto/sha1"
+	"crypto/sha256"
+	"crypto/sha512"
+	"errors"
+	"hash"
+	"hash/adler32"
+	"hash/crc32"
+	"hash/crc64"
+	"hash/fnv"
+	"io"
+	"sort"
+
+	"github.com/kisom/goutils/assert"
+	"golang.org/x/crypto/blake2b"
+	"golang.org/x/crypto/blake2s"
+	"golang.org/x/crypto/md4"
+	"golang.org/x/crypto/ripemd160"
+	"golang.org/x/crypto/sha3"
+)
+
+func sha224Slicer(bs []byte) []byte {
+	sum := sha256.Sum224(bs)
+	return sum[:]
+}
+
+func sha256Slicer(bs []byte) []byte {
+	sum := sha256.Sum256(bs)
+	return sum[:]
+}
+
+func sha384Slicer(bs []byte) []byte {
+	sum := sha512.Sum384(bs)
+	return sum[:]
+}
+
+func sha512Slicer(bs []byte) []byte {
+	sum := sha512.Sum512(bs)
+	return sum[:]
+}
+
+var sliceFunctions = map[string]func([]byte) []byte{
+	"sha224": sha224Slicer,
+	"sha256": sha256Slicer,
+	"sha384": sha384Slicer,
+	"sha512": sha512Slicer,
+}
+
+// Hash represents a generic hash function that may or may not be secure. It
+// satisfies the hash.Hash interface.
+type Hash struct {
+	hash.Hash
+	secure bool
+	algo string
+}
+
+// HashAlgo returns the name of the underlying hash algorithm.
+func (h *Hash) HashAlgo() string {
+	return h.algo
+}
+
+// IsSecure returns true if the Hash is a cryptographic hash.
+func (h *Hash) IsSecure() bool {
+	return h.secure
+}
+
+// Sum32 returns true if the underlying hash is a 32-bit hash; if is, the
+// uint32 parameter will contain the hash.
+func (h *Hash) Sum32() (uint32, bool) {
+	h32, ok := h.Hash.(hash.Hash32)
+	if !ok {
+		return 0, false
+	}
+
+	return h32.Sum32(), true
+}
+
+// IsHash32 returns true if the underlying hash is a 32-bit hash function.
+func (h *Hash) IsHash32() bool {
+	_, ok := h.Hash.(hash.Hash32)
+	return ok
+}
+
+// Sum64 returns true if the underlying hash is a 64-bit hash; if is, the
+// uint64 parameter will contain the hash.
+func (h *Hash) Sum64() (uint64, bool) {
+	h64, ok := h.Hash.(hash.Hash64)
+	if !ok {
+		return 0, false
+	}
+
+	return h64.Sum64(), true
+}
+
+// IsHash64 returns true if the underlying hash is a 64-bit hash function.
+func (h *Hash) IsHash64() bool {
+	_, ok := h.Hash.(hash.Hash64)
+	return ok
+}
+
+func blakeFunc(bf func(key []byte) (hash.Hash, error)) func() hash.Hash {
+	return func() hash.Hash {
+		h, err := bf(nil)
+		assert.NoError(err, "while constructing a BLAKE2 hash function")
+		return h
+	}
+}
+
+var secureHashes = map[string]func() hash.Hash{
+	"ripemd160":   ripemd160.New,
+	"sha224":      sha256.New224,
+	"sha256":      sha256.New,
+	"sha384":      sha512.New384,
+	"sha512":      sha512.New,
+	"sha3-224":    sha3.New224,
+	"sha3-256":    sha3.New256,
+	"sha3-384":    sha3.New384,
+	"sha3-512":    sha3.New512,
+	"blake2s-256": blakeFunc(blake2s.New256),
+	"blake2b-256": blakeFunc(blake2b.New256),
+	"blake2b-384": blakeFunc(blake2b.New384),
+	"blake2b-512": blakeFunc(blake2b.New512),
+}
+
+func newHash32(f func () hash.Hash32) func () hash.Hash {
+	return func() hash.Hash {
+		return f()
+	}
+}
+
+func newHash64(f func () hash.Hash64) func () hash.Hash {
+	return func() hash.Hash {
+		return f()
+	}
+}
+
+func newCRC64(tab uint64) func () hash.Hash {
+	return newHash64(
+		func() hash.Hash64 {
+			return crc64.New(crc64.MakeTable(tab))
+		})
+}
+
+var insecureHashes = map[string]func() hash.Hash{
+	"md4":        md4.New,
+	"md5":        md5.New,
+	"sha1":       sha1.New,
+	"adler32":    newHash32(adler32.New),
+	"crc32-ieee": newHash32(crc32.NewIEEE),
+	"crc64":      newCRC64(crc64.ISO),
+	"crc64-ecma": newCRC64(crc64.ECMA),
+	"fnv1-32a":   newHash32(fnv.New32a),
+	"fnv1-32":    newHash32(fnv.New32),
+	"fnv1-64a":   newHash64(fnv.New64a),
+	"fnv1-64":    newHash64(fnv.New64),
+}
+
+// New returns a new Hash for the specified algorithm.
+func New(algo string) (*Hash, error) {
+	h := &Hash{algo: algo}
+
+	hf, ok := secureHashes[algo]
+	if ok {
+		h.Hash = hf()
+		h.secure = true
+		return h, nil
+	}
+
+	hf, ok = insecureHashes[algo]
+	if ok {
+		h.Hash = hf()
+		h.secure = false
+		return h, nil
+	}
+
+	return nil, errors.New("chash: unsupport hash algorithm " + algo)
+}
+
+// Sum returns the digest (not the hex digest) of the data using the given
+// algorithm.
+func Sum(algo string, data []byte) ([]byte, error) {
+	h, err := New(algo)
+	if err != nil {
+		return nil, err
+	}
+
+	_, err = h.Write(data)
+	if err != nil {
+		return nil, err
+	}
+
+	return h.Sum(nil), nil
+}
+
+// SumReader reads all the data from the given io.Reader and returns the
+// digest (not the hex digest) from the specified algorithm.
+func SumReader(algo string, r io.Reader) ([]byte, error) {
+	h, err := New(algo)
+	if err != nil {
+		return nil, err
+	}
+
+	_, err = io.Copy(h, r)
+	if err != nil {
+		return nil, err
+	}
+
+	return h.Sum(nil), nil
+}
+
+var insecureHashList, secureHashList, hashList []string
+
+func init() {
+	shl := len(secureHashes)   // secure hash list length
+	ihl := len(insecureHashes) // insecure hash list length
+	ahl := shl + ihl           // all hash list length
+
+	insecureHashList = make([]string, 0, ihl)
+	secureHashList = make([]string, 0, shl)
+	hashList = make([]string, 0, ahl)
+
+	for algo := range insecureHashes {
+		insecureHashList = append(insecureHashList, algo)
+	}
+	sort.Strings(insecureHashList)
+
+	for algo := range secureHashes {
+		secureHashList = append(secureHashList, algo)
+	}
+	sort.Strings(secureHashList)
+
+	hashList = append(hashList, insecureHashList...)
+	hashList = append(hashList, secureHashList...)
+	sort.Strings(hashList)
+}
+
+// HashList returns a sorted list of all the hash algorithms supported by the
+// package.
+func HashList() []string {
+	return hashList[:]
+}
+
+// SecureHashList returns a sorted list of all the secure (cryptographic) hash
+// algorithms supported by the package.
+func SecureHashList() []string {
+	return secureHashList[:]
+}
+
+// InsecureHashList returns a sorted list of all the insecure hash algorithms
+// supported by the package.
+func InsecureHashList() []string {
+	return insecureHashList[:]
+}

ahash/ahash_test.go

@@ -0,0 +1,141 @@
+package ahash
+
+import (
+	"bytes"
+	"fmt"
+	"testing"
+
+	"github.com/kisom/goutils/assert"
+)
+
+func TestSecureHash(t *testing.T) {
+	algo := "sha256"
+	h, err := New(algo)
+	assert.NoErrorT(t, err)
+	assert.BoolT(t, h.IsSecure(), algo + " should be a secure hash")
+	assert.BoolT(t, h.HashAlgo() == algo, "hash returned the wrong HashAlgo")
+	assert.BoolT(t, !h.IsHash32(), algo + " isn't actually a 32-bit hash")
+	assert.BoolT(t, !h.IsHash64(), algo + " isn't actually a 64-bit hash")
+	
+	var data []byte
+	var expected = "e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855"
+	sum, err := Sum(algo, data)
+	assert.NoErrorT(t, err)
+	assert.BoolT(t, fmt.Sprintf("%x", sum) == expected, fmt.Sprintf("expected hash %s but have %x", expected, sum))
+
+	data = []byte("hello, world")
+	buf := bytes.NewBuffer(data)
+	expected = "09ca7e4eaa6e8ae9c7d261167129184883644d07dfba7cbfbc4c8a2e08360d5b"
+	sum, err = SumReader(algo, buf)
+	assert.NoErrorT(t, err)
+	assert.BoolT(t, fmt.Sprintf("%x", sum) == expected, fmt.Sprintf("expected hash %s but have %x", expected, sum))
+	
+	data = []byte("hello world")
+	_, err = h.Write(data)
+	assert.NoErrorT(t, err)
+	unExpected := "09ca7e4eaa6e8ae9c7d261167129184883644d07dfba7cbfbc4c8a2e08360d5b"
+	sum = h.Sum(nil)
+	assert.BoolT(t, fmt.Sprintf("%x", sum) != unExpected, fmt.Sprintf("hash shouldn't have returned %x", unExpected))
+}
+
+func TestInsecureHash(t *testing.T) {
+	algo := "md5"
+	h, err := New(algo)
+	assert.NoErrorT(t, err)
+	assert.BoolT(t, !h.IsSecure(), algo + " shouldn't be a secure hash")
+	assert.BoolT(t, h.HashAlgo() == algo, "hash returned the wrong HashAlgo")
+	assert.BoolT(t, !h.IsHash32(), algo + " isn't actually a 32-bit hash")
+	assert.BoolT(t, !h.IsHash64(), algo + " isn't actually a 64-bit hash")
+
+	var data []byte
+	var expected = "d41d8cd98f00b204e9800998ecf8427e"
+	sum, err := Sum(algo, data)
+	assert.NoErrorT(t, err)
+	assert.BoolT(t, fmt.Sprintf("%x", sum) == expected, fmt.Sprintf("expected hash %s but have %x", expected, sum))
+
+	data = []byte("hello, world")
+	buf := bytes.NewBuffer(data)
+	expected = "e4d7f1b4ed2e42d15898f4b27b019da4"
+	sum, err = SumReader(algo, buf)
+	assert.NoErrorT(t, err)
+	assert.BoolT(t, fmt.Sprintf("%x", sum) == expected, fmt.Sprintf("expected hash %s but have %x", expected, sum))
+	
+	data = []byte("hello world")
+	_, err = h.Write(data)
+	assert.NoErrorT(t, err)
+	unExpected := "e4d7f1b4ed2e42d15898f4b27b019da4"
+	sum = h.Sum(nil)
+	assert.BoolT(t, fmt.Sprintf("%x", sum) != unExpected, fmt.Sprintf("hash shouldn't have returned %x", unExpected))
+}
+
+func TestHash32(t *testing.T) {
+	algo := "crc32-ieee"
+	h, err := New(algo)
+	assert.NoErrorT(t, err)
+	assert.BoolT(t, !h.IsSecure(), algo + " shouldn't be a secure hash")
+	assert.BoolT(t, h.HashAlgo() == algo, "hash returned the wrong HashAlgo")
+	assert.BoolT(t, h.IsHash32(), algo + " is actually a 32-bit hash")
+	assert.BoolT(t, !h.IsHash64(), algo + " isn't actually a 64-bit hash")
+	
+	var data []byte
+	var expected uint32
+	
+	h.Write(data)
+	sum, ok := h.Sum32()
+	assert.BoolT(t, ok, algo + " should be able to return a Sum32")
+	assert.BoolT(t, expected == sum, fmt.Sprintf("%s returned the %d but expected %d", algo, sum, expected))
+	
+	data = []byte("hello, world")
+	expected = 0xffab723a
+	h.Write(data)
+	sum, ok = h.Sum32()
+	assert.BoolT(t, ok, algo + " should be able to return a Sum32")
+	assert.BoolT(t, expected == sum, fmt.Sprintf("%s returned the %d but expected %d", algo, sum, expected))
+	
+	h.Reset()
+	data = []byte("hello world")
+	h.Write(data)
+	sum, ok = h.Sum32()
+	assert.BoolT(t, ok, algo + " should be able to return a Sum32")
+	assert.BoolT(t, expected != sum, fmt.Sprintf("%s returned %d but shouldn't have", algo, sum, expected))
+}
+
+func TestHash64(t *testing.T) {
+	algo := "crc64"
+	h, err := New(algo)
+	assert.NoErrorT(t, err)
+	assert.BoolT(t, !h.IsSecure(), algo + " shouldn't be a secure hash")
+	assert.BoolT(t, h.HashAlgo() == algo, "hash returned the wrong HashAlgo")
+	assert.BoolT(t, h.IsHash64(), algo + " is actually a 64-bit hash")
+	assert.BoolT(t, !h.IsHash32(), algo + " isn't actually a 32-bit hash")
+	
+	var data []byte
+	var expected uint64
+	
+	h.Write(data)
+	sum, ok := h.Sum64()
+	assert.BoolT(t, ok, algo + " should be able to return a Sum64")
+	assert.BoolT(t, expected == sum, fmt.Sprintf("%s returned the %d but expected %d", algo, sum, expected))
+	
+	data = []byte("hello, world")
+	expected = 0x16c45c0eb1d9c2ec
+	h.Write(data)
+	sum, ok = h.Sum64()
+	assert.BoolT(t, ok, algo + " should be able to return a Sum64")
+	assert.BoolT(t, expected == sum, fmt.Sprintf("%s returned the %d but expected %d", algo, sum, expected))
+	
+	h.Reset()
+	data = []byte("hello world")
+	h.Write(data)
+	sum, ok = h.Sum64()
+	assert.BoolT(t, ok, algo + " should be able to return a Sum64")
+	assert.BoolT(t, expected != sum, fmt.Sprintf("%s returned %d but shouldn't have", algo, sum, expected))
+}
+
+func TestListLengthSanity(t *testing.T) {
+	all := HashList()
+	secure := SecureHashList()
+	insecure := InsecureHashList()
+	
+	assert.BoolT(t, len(all) == len(secure) + len(insecure))
+}