github.com/sandwich-go/boost@v1.3.29/xcrypto/algorithm/vigenere/vigenere.go (about)

     1  package vigenere
     2  
     3  // Sanitize 剔除无效的字节
     4  func Sanitize(key []byte) []byte {
     5  	if len(key) == 0 {
     6  		return key
     7  	}
     8  	var out = make([]byte, 0, len(key))
     9  	for _, v := range key {
    10  		if 65 <= v && v <= 90 {
    11  			out = append(out, v)
    12  		} else if 97 <= v && v <= 122 {
    13  			out = append(out, v-32)
    14  		}
    15  	}
    16  	return out
    17  }
    18  
    19  func encode(a, b byte) byte {
    20  	return (((a - 'A') + (b - 'A')) % 26) + 'A'
    21  }
    22  
    23  func decode(a, b byte) byte {
    24  	return ((((a - 'A') - (b - 'A')) + 26) % 26) + 'A'
    25  }
    26  
    27  // Encrypt 使用 key 进行加密
    28  func Encrypt(src []byte, key []byte) []byte {
    29  	if len(key) == 0 {
    30  		return src
    31  	}
    32  	out := make([]byte, 0, len(src))
    33  	for i, v := range src {
    34  		out = append(out, encode(v, key[i%len(key)]))
    35  	}
    36  	return out
    37  }
    38  
    39  // Decrypt 使用 key 进行解密
    40  func Decrypt(src, key []byte) []byte {
    41  	if len(key) == 0 {
    42  		return src
    43  	}
    44  	out := make([]byte, 0, len(src))
    45  	for i, v := range src {
    46  		out = append(out, decode(v, key[i%len(key)]))
    47  	}
    48  	return out
    49  }
    50  
    51  // EncryptAndInplace  使用 key 进行加密，并且替换 src
    52  func EncryptAndInplace(src, key []byte) {
    53  	if len(key) == 0 {
    54  		return
    55  	}
    56  	for i, v := range src {
    57  		src[i] = encode(v, key[i%len(key)])
    58  	}
    59  }
    60  
    61  // DecryptAndInplace  使用 key 进行解密，并且替换 src
    62  func DecryptAndInplace(src, key []byte) {
    63  	if len(key) == 0 {
    64  		return
    65  	}
    66  	for i, v := range src {
    67  		src[i] = decode(v, key[i%len(key)])
    68  	}
    69  }