github.com/kaydxh/golang@v0.0.131/go/crypto/sha256/sha256.go (about)

     1  /*
     2   *Copyright (c) 2022, kaydxh
     3   *
     4   *Permission is hereby granted, free of charge, to any person obtaining a copy
     5   *of this software and associated documentation files (the "Software"), to deal
     6   *in the Software without restriction, including without limitation the rights
     7   *to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
     8   *copies of the Software, and to permit persons to whom the Software is
     9   *furnished to do so, subject to the following conditions:
    10   *
    11   *The above copyright notice and this permission notice shall be included in all
    12   *copies or substantial portions of the Software.
    13   *
    14   *THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
    15   *IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
    16   *FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
    17   *AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
    18   *LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
    19   *OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
    20   *SOFTWARE.
    21   */
    22  package sha256
    23  
    24  import (
    25  	"bytes"
    26  	"crypto/sha256"
    27  	"encoding/hex"
    28  	"io"
    29  	"os"
    30  
    31  	os_ "github.com/kaydxh/golang/go/os"
    32  )
    33  
    34  func SumBytes(b []byte) string {
    35  	h := sha256.New()
    36  	h.Write(b)
    37  	return hex.EncodeToString(h.Sum(nil))
    38  }
    39  
    40  func SumString(s string) string {
    41  	return SumBytes([]byte(s))
    42  }
    43  
    44  func SumReader(r io.Reader) (string, error) {
    45  	h := sha256.New()
    46  	if _, err := io.Copy(h, r); err != nil {
    47  		return "", err
    48  	}
    49  
    50  	return hex.EncodeToString(h.Sum(nil)), nil
    51  }
    52  
    53  func SumReaderN(r io.Reader, n int64) (string, error) {
    54  	h := sha256.New()
    55  	if _, err := io.CopyN(h, r, n); err != nil {
    56  		return "", err
    57  	}
    58  
    59  	return hex.EncodeToString(h.Sum(nil)), nil
    60  }
    61  
    62  func SumReaderAt(r io.ReaderAt, offset, length int64) (string, error) {
    63  	h := sha256.New()
    64  	buf := make([]byte, 1024)
    65  	var total int64
    66  
    67  	for total < length {
    68  		n, err := r.ReadAt(buf, offset)
    69  		if err == nil || err == io.EOF {
    70  			if n > 0 {
    71  				_, tmpErr := io.CopyN(h, bytes.NewReader(buf), int64(n))
    72  				if tmpErr != nil {
    73  					return "", tmpErr
    74  				}
    75  				offset += int64(n)
    76  				total += int64(n)
    77  
    78  			}
    79  
    80  			if err == io.EOF {
    81  				break
    82  			}
    83  		} else {
    84  			return "", err
    85  		}
    86  
    87  	}
    88  
    89  	return hex.EncodeToString(h.Sum(nil)), nil
    90  }
    91  
    92  func SumFile(fileName string) (string, error) {
    93  	file, err := os_.OpenFile(fileName, true)
    94  	if err != nil {
    95  		return "", err
    96  	}
    97  	defer file.Close()
    98  
    99  	return SumReader(file)
   100  }
   101  
   102  func SumFileAt(fileName string, offset int64, length int64) (string, error) {
   103  	file, err := os_.OpenAll(fileName, os.O_RDWR, os.ModePerm)
   104  	if err != nil {
   105  		return "", err
   106  	}
   107  	defer file.Close()
   108  
   109  	return SumReaderAt(file, offset, length)
   110  }