+++ /dev/null
-package multihash
-
-import (
- "crypto/sha1"
- "crypto/sha512"
- "errors"
- "fmt"
-
- keccak "github.com/gxed/hashland/keccakpg"
- murmur3 "github.com/gxed/hashland/murmur3"
- blake2b "github.com/minio/blake2b-simd"
- sha256 "github.com/minio/sha256-simd"
- blake2s "golang.org/x/crypto/blake2s"
- sha3 "golang.org/x/crypto/sha3"
-)
-
-// ErrSumNotSupported is returned when the Sum function code is not implemented
-var ErrSumNotSupported = errors.New("Function not implemented. Complain to lib maintainer.")
-
-// HashFunc is a hash function that hashes data into digest.
-//
-// The length is the size the digest will be truncated to. While the hash
-// function isn't responsible for truncating the digest, it may want to error if
-// the length is invalid for the hash function (e.g., truncation would make the
-// hash useless).
-type HashFunc func(data []byte, length int) (digest []byte, err error)
-
-// funcTable maps multicodec values to hash functions.
-var funcTable = make(map[uint64]HashFunc)
-
-// Sum obtains the cryptographic sum of a given buffer. The length parameter
-// indicates the length of the resulting digest and passing a negative value
-// use default length values for the selected hash function.
-func Sum(data []byte, code uint64, length int) (Multihash, error) {
- if !ValidCode(code) {
- return nil, fmt.Errorf("invalid multihash code %d", code)
- }
-
- if length < 0 {
- var ok bool
- length, ok = DefaultLengths[code]
- if !ok {
- return nil, fmt.Errorf("no default length for code %d", code)
- }
- }
-
- hashFunc, ok := funcTable[code]
- if !ok {
- return nil, ErrSumNotSupported
- }
-
- d, err := hashFunc(data, length)
- if err != nil {
- return nil, err
- }
- if length >= 0 {
- d = d[:length]
- }
- return Encode(d, code)
-}
-
-func sumBlake2s(data []byte, size int) ([]byte, error) {
- if size != 32 {
- return nil, fmt.Errorf("unsupported length for blake2s: %d", size)
- }
- d := blake2s.Sum256(data)
- return d[:], nil
-}
-func sumBlake2b(data []byte, size int) ([]byte, error) {
- hasher, err := blake2b.New(&blake2b.Config{Size: uint8(size)})
- if err != nil {
- return nil, err
- }
-
- if _, err := hasher.Write(data); err != nil {
- return nil, err
- }
-
- return hasher.Sum(nil)[:], nil
-}
-
-func sumID(data []byte, length int) ([]byte, error) {
- if length >= 0 && length != len(data) {
- return nil, fmt.Errorf("the length of the identity hash (%d) must be equal to the length of the data (%d)",
- length, len(data))
-
- }
- return data, nil
-}
-
-func sumSHA1(data []byte, length int) ([]byte, error) {
- a := sha1.Sum(data)
- return a[0:20], nil
-}
-
-func sumSHA256(data []byte, length int) ([]byte, error) {
- a := sha256.Sum256(data)
- return a[0:32], nil
-}
-
-func sumDoubleSHA256(data []byte, length int) ([]byte, error) {
- val, _ := sumSHA256(data, len(data))
- return sumSHA256(val, len(val))
-}
-
-func sumSHA512(data []byte, length int) ([]byte, error) {
- a := sha512.Sum512(data)
- return a[0:64], nil
-}
-
-func sumKeccak224(data []byte, length int) ([]byte, error) {
- h := keccak.New224()
- h.Write(data)
- return h.Sum(nil), nil
-}
-
-func sumKeccak256(data []byte, length int) ([]byte, error) {
- h := keccak.New256()
- h.Write(data)
- return h.Sum(nil), nil
-}
-
-func sumKeccak384(data []byte, length int) ([]byte, error) {
- h := keccak.New384()
- h.Write(data)
- return h.Sum(nil), nil
-}
-
-func sumKeccak512(data []byte, length int) ([]byte, error) {
- h := keccak.New512()
- h.Write(data)
- return h.Sum(nil), nil
-}
-
-func sumSHA3_512(data []byte, length int) ([]byte, error) {
- a := sha3.Sum512(data)
- return a[:], nil
-}
-
-func sumMURMUR3(data []byte, length int) ([]byte, error) {
- number := murmur3.Sum32(data)
- bytes := make([]byte, 4)
- for i := range bytes {
- bytes[i] = byte(number & 0xff)
- number >>= 8
- }
- return bytes, nil
-}
-
-func sumSHAKE128(data []byte, length int) ([]byte, error) {
- bytes := make([]byte, 32)
- sha3.ShakeSum128(bytes, data)
- return bytes, nil
-}
-
-func sumSHAKE256(data []byte, length int) ([]byte, error) {
- bytes := make([]byte, 64)
- sha3.ShakeSum256(bytes, data)
- return bytes, nil
-}
-
-func sumSHA3_384(data []byte, length int) ([]byte, error) {
- a := sha3.Sum384(data)
- return a[:], nil
-}
-
-func sumSHA3_256(data []byte, length int) ([]byte, error) {
- a := sha3.Sum256(data)
- return a[:], nil
-}
-
-func sumSHA3_224(data []byte, length int) ([]byte, error) {
- a := sha3.Sum224(data)
- return a[:], nil
-}
-
-func registerStdlibHashFuncs() {
- RegisterHashFunc(ID, sumID)
- RegisterHashFunc(SHA1, sumSHA1)
- RegisterHashFunc(SHA2_512, sumSHA512)
-}
-
-func registerNonStdlibHashFuncs() {
- RegisterHashFunc(SHA2_256, sumSHA256)
- RegisterHashFunc(DBL_SHA2_256, sumDoubleSHA256)
-
- RegisterHashFunc(KECCAK_224, sumKeccak224)
- RegisterHashFunc(KECCAK_256, sumKeccak256)
- RegisterHashFunc(KECCAK_384, sumKeccak384)
- RegisterHashFunc(KECCAK_512, sumKeccak512)
-
- RegisterHashFunc(SHA3_224, sumSHA3_224)
- RegisterHashFunc(SHA3_256, sumSHA3_256)
- RegisterHashFunc(SHA3_384, sumSHA3_384)
- RegisterHashFunc(SHA3_512, sumSHA3_512)
-
- RegisterHashFunc(MURMUR3, sumMURMUR3)
-
- RegisterHashFunc(SHAKE_128, sumSHAKE128)
- RegisterHashFunc(SHAKE_256, sumSHAKE256)
-
- // Blake family of hash functions
- // BLAKE2S
- for c := uint64(BLAKE2S_MIN); c <= BLAKE2S_MAX; c++ {
- size := int(c - BLAKE2S_MIN + 1)
- RegisterHashFunc(c, func(buf []byte, _ int) ([]byte, error) {
- return sumBlake2s(buf, size)
- })
- }
- // BLAKE2B
- for c := uint64(BLAKE2B_MIN); c <= BLAKE2B_MAX; c++ {
- size := int(c - BLAKE2B_MIN + 1)
- RegisterHashFunc(c, func(buf []byte, _ int) ([]byte, error) {
- return sumBlake2b(buf, size)
- })
- }
-}
-
-func init() {
- registerStdlibHashFuncs()
- registerNonStdlibHashFuncs()
-}
-
-// RegisterHashFunc adds an entry to the package-level code -> hash func map.
-// The hash function must return at least the requested number of bytes. If it
-// returns more, the hash will be truncated.
-func RegisterHashFunc(code uint64, hashFunc HashFunc) error {
- if !ValidCode(code) {
- return fmt.Errorf("code %v not valid", code)
- }
-
- _, ok := funcTable[code]
- if ok {
- return fmt.Errorf("hash func for code %v already registered", code)
- }
-
- funcTable[code] = hashFunc
- return nil
-}
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