github.com/deroproject/derosuite@v2.1.6-1.0.20200307070847-0f2e589c7a2b+incompatible/crypto/hash.go (about)

     1  // Copyright 2017-2018 DERO Project. All rights reserved.
     2  // Use of this source code in any form is governed by RESEARCH license.
     3  // license can be found in the LICENSE file.
     4  // GPG: 0F39 E425 8C65 3947 702A  8234 08B2 0360 A03A 9DE8
     5  //
     6  //
     7  // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY
     8  // EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
     9  // MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL
    10  // THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
    11  // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
    12  // PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
    13  // INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
    14  // STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF
    15  // THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
    16  
    17  package crypto
    18  
    19  import "fmt"
    20  import "encoding/hex"
    21  
    22  const (
    23  	ChecksumLength = 4 // for addresses
    24  	HashLength     = 32
    25  )
    26  
    27  type Hash [HashLength]byte
    28  type Checksum [ChecksumLength]byte
    29  
    30  func (h Hash) MarshalText() ([]byte, error) {
    31  	return []byte(fmt.Sprintf("%x", h[:])), nil
    32  }
    33  
    34  func (h *Hash) UnmarshalText(data []byte) (err error) {
    35  	byteSlice, _ := hex.DecodeString(string(data))
    36  	if len(byteSlice) != 32 {
    37  		return fmt.Errorf("Incorrect hash size")
    38  	}
    39  	copy(h[:], byteSlice)
    40  	return
    41  }
    42  
    43  // stringifier
    44  func (h Hash) String() string {
    45  	return fmt.Sprintf("%x", h[:])
    46  }
    47  
    48  // convert a hash of hex form to binary form, returns a zero hash if any error
    49  // TODO this should be in crypto
    50  func HashHexToHash(hash_hex string) (hash Hash) {
    51  	hash_raw, err := hex.DecodeString(hash_hex)
    52  
    53  	if err != nil {
    54  		//panic(fmt.Sprintf("Cannot hex decode checkpint hash \"%s\"", hash_hex))
    55  		return hash
    56  	}
    57  
    58  	if len(hash_raw) != 32 {
    59  		//panic(fmt.Sprintf(" hash not 32 byte size Cannot hex decode checkpint hash \"%s\"", hash_hex))
    60  		return hash
    61  	}
    62  
    63  	copy(hash[:], hash_raw)
    64  	return
    65  }