Shell脚本实现Base64 加密解密 2023.09.09 shell

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加密算法

#!/bin/bash

# 全局变量
str=""

base64_encode_string(){
# 源数据
source_string=$1
echo "源数据：$1"
# 判断是否为空
if [ 0 -eq "${#source_string}" ]; then
	echo "输入为空，退出"

	return
fi

echo "正在执行..."
# 编码集Wnrm0b7QPpI1FGBYVizZXN84vTJqocOuD9aHdgSlt2jRyAKEe6kCxhsfwL5M3U+/
BASE64_CODE_TABLE=(W n r m 0 b 7 Q P p I 1 F G B Y V i z Z X N 8 4 v T J q o c O u D 9 a H d g S l t 2 j R y A K E e 6 k C x h s f w L 5 M 3 U + /)
# 不知道
FIRST_SOURCE_BYTE_DIVIDEND=0X04
SECOND_SOURCE_BYTE_DIVIDEND=0X10
THIRD_SOURCE_BYTE_DIVIDEND=0X40
# 标记
encode_state=1
#
last_source_byte=""
# 结果
result=""

# 将字符转化成ASCII码值
for((i=0;i<${#source_string};++i)){
	#curChar='printf "%d" "${#source_string:i:1}";'
	curChar=`printf "%d" "'${source_string:i:1}";`
	echo curChar=$curChar

case $encode_state in
1)

	index=$(( $curChar / $FIRST_SOURCE_BYTE_DIVIDEND ))
	# echo "INDEX IN STATE 1 IS : $index"
	result="$result${BASE64_CODE_TABLE[$index]}"
	echo "结果：" $result
	encode_state=2;;

2)

	index_high=$(( ($last_source_byte % $FIRST_SOURCE_BYTE_DIVIDEND)* 0X10 ))
	index_low=$(( $curChar / $SECOND_SOURCE_BYTE_DIVIDEND ))
	index=$(( $index_high + $index_low ))
	# echo "index in state 2 is: $index"
	result="$result${BASE64_CODE_TABLE[$index]}"
	echo "结果：$result"
	encode_state=3;;
3)
	index_high=$(( ($last_source_byte % $SECOND_SOURCE_BYTE_DIVIDEND) * 0X04 ))
	index_low=$(( $curChar / $THIRD_SOURCE_BYTE_DIVIDEND ))
	index=$(( $curChar % $THIRD_SOURCE_BYTE_DIVIDEND ))
	# echo "index2 in state 3 is: $index"
	result="$result${BASE64_CODE_TABLE[$index]}"
	echo "结果：$result"
	# 追加最后一位
            index=$(( $curChar % 0x10 ))
	result="$result${BASE64_CODE_TABLE[$index]}"
	echo "追加结果：$result"
	encode_state=1;;

esac

last_source_byte=$curChar
}

# process pading
case $encode_state in
2)
	echo $FIRST_BYTE_DIVIDEND

	index=$(( ($last_source_byte % $FIRST_SOURCE_BYTE_DIVIDEND) * 0X10 ))
	#echo "index in pading state 2 is: $index"
	result="$result${BASE64_CODE_TABLE[$index]}==";;
3)
	index=$(( ($last_source_byte % $SECOND_SOURCE_BYTE_DIVIDEND) * 0X04 ))
	#echo "index in pading state 3 is: $index"
	result="$result${BASE64_CODE_TABLE[$index]}=";;
esac
echo "添加后缀：$result"
str=$result

}


    # 第二种


# main函数

echo "开始加密..."

read m
echo $m
read n

echo "-------------------"

cat $1 |while read line
do
from=$line
base64_encode_string $from
# str=$?
# echo "输出：" $str
# 写入文件
echo "$str" >> to
done

# 加密

# 写入文件
# base64_encode_string $1

echo "加密结束..."}

解密算法

#!/bin/bash

# 全局变量
str=""
_str=""
# 编码集Wnrm0b7QPpI1FGBYVizZXN84vTJqocOuD9aHdgSlt2jRyAKEe6kCxhsfwL5M3U+/
BASE64_CODE_TABLE=(W n r m 0 b 7 Q P p I 1 F G B Y V i z Z X N 8 4 v T J q o c O u D 9 a H d g S l t 2 j R y A K E e 6 k C x h s f w L 5 M 3 U + /)

#16#---->ascii
fun(){
a=$1
b=`printf "%d" $a`
#echo $b |awk '{printf("%c", $1)}'
_str=`echo $b |awk '{printf("%c", $1)}'`
}


# 四个字符转化为正确的三个字符
get(){
# get
get=$1
echo "数据源" $1
# to
to=""
# size
size=4
if [[ $2 = 1 ]]; then
	size = 3
elif [[ $2 = 2 ]]; then
	size =2
fi
for((i=0;i<size;++i))do
	# echo "循环I：$i ${get:i:1}"
	for((j=0;j<64;j++))do
		# echo "当前：$j ${BASE64_CODE_TABLE[$j]}"
		if [[ ${get:i:1} = ${BASE64_CODE_TABLE[$j]} ]]; then
			if [[ i < size-1 ]];then
				to=$(( ($to + $j)* 0x10))

				# 此时为十进制
				echo "匹配：$i $j $to ${get:i:1}"
			else
				to=$(($to + $j))
			fi
			break
		fi
	done
done
get=""
# 十进制转化为十六进制
echo "十六进制结果" $to
if [[ size = 1 ]]; then
	to=$to/0x04
	tmp=$to / 0x100
	tmp="\x${tmp}"
	tmp=`printf "$tmp"`

	to=$to >> 8
	tmp="\x${to}"
	tmp=`printf "$tmp"`
	get=$get $tmp
elif [[ size = 2 ]]; then
	to=$to/0x10
	tmp="\x${to}"
	tmp=`printf "$tmp"`
	get=$get $tmp
else
	printf "%d" $(( ($to / 65536) ))
	tmp=$(( ($to / 65536) ))
	fun $tmp
	echo "_str:" $_str
	to=$(( ($to % 65536) ))
	tmp=$(( ($to / 256) ))
	# tmp="\x${tmp}"
	echo `printf "$tmp"`
	tmp=`printf $tmp`
	get="$get" "$tmp"
	to=$to >> 8
	get=$get `echo -e '\x${to % 0x100}'`
	to=$to >> 8
	get=$get `echo -e '\x${to % 0x100}'`
fi
echo "get----------->"
echo $get
}

base64_encode_string(){
# 源数据
source_string=$1
last=0
last_to=0

# 结果
 result=""

# 判断是否为空
if [ 0 -eq "${#source_string}" ]; then
echo "输入为空，退出"
	return
fi

# 结尾标记
end=0
echo "结尾： ${source_string:${#source_string}-3}"

if [ ${source_string:${#source_string}-2} = "==" ]; then
    	end=2
elif [ ${source_string:${#source_string}-1} = "=" ]; then
    	end=1
else
    	end=0
fi

# 判断字符串长度
len=${#source_string}
if [[ 4 = len ]]; then
	echo "字符串长度小于4"

else
	echo "字符串长度大于4"
	m=${#source_string}-4
	for((i=0;i<m;))
	do
		get ${source_string:i:4} 0
		result=$result $?
		i = $i + 4
	done
fi

echo "对结尾进行处理..."
last=${source_string:${#source_string}-4:4}
echo $last
case $end in
0)
	;;
1)
	;;
2)
	get $last 2
	result=$result $?;;

esac

# 编码集Wnrm0b7QPpI1FGBYVizZXN84vTJqocOuD9aHdgSlt2jRyAKEe6kCxhsfwL5M3U+/
# BASE64_CODE_TABLE=(W n r m 0 b 7 Q P p I 1 F G B Y V i z Z X N 8 4 v T J q o c O u D 9 a H d g S l t 2 j R y A K E e 6 k C x h s f w L 5 M 3 U + /)
# 第一个字符取前六位，所以是对0100取整去掉最后两位，第二个是前一个字符的后两位和这个字符的
FIRST_SOURCE_BYTE_DIVIDEND=0X04
SECOND_SOURCE_BYTE_DIVIDEND=0X10
THIRD_SOURCE_BYTE_DIVIDEND=0X40
# 标记
encode_state=1
#
last_source_byte=""
# 结果
result=""

# 将字符转化成ASCII码值
for((i=0;i<${#source_string};++i)){
	#curChar='printf "%d" "${#source_string:i:1}";'
	curChar=`printf "%d" "'${source_string:i:1}";`
	echo curChar=$curChar

case $encode_state in
1)

	index=$(( $curChar / $FIRST_SOURCE_BYTE_DIVIDEND ))
	echo "INDEX IN STATE 1 IS : $index"
	result="$result${BASE64_CODE_TABLE[$index]}"
	encode_state=2;;

2)

	index_high=$(( ($last_source_byte % $FIRST_SOURCE_BYTE_DIVIDEND)* 0X10 ))
	index_low=$(( $curChar / $SECOND_SOURCE_BYTE_DIVIDEND ))
	index=$(( $index_high + $index_low ))
	echo "index in state 2 is: $index"
	result="$result${BASE64_CODE_TABLE[$index]}"
	encode_state=3;;
3)
	index_high=$(( ($last_source_byte % $SECOND_SOURCE_BYTE_DIVIDEND) * 0X04 ))
	index_low=$(( $curChar / $THIRD_SOURCE_BYTE_DIVIDEND ))
	index=$(( $curChar % $THIRD_SOURCE_BYTE_DIVIDEND ))
	echo "index2 in state 3 is: $index"
	result="$result${BASE64_CODE_TABLE[$index]}"
	encode_state=1;;

esac

last_source_byte=$curChar
}

# process pading
case $encode_state in
2)
	echo $FIRST_BYTE_DIVIDEND

	index=$(( ($last_source_byte % $FIRST_SOURCE_BYTE_DIVIDEND) * 0X10 ))
	#echo "index in pading state 2 is: $index"
	result="$result${BASE64_CODE_TABLE[$index]}==";;
3)
	index=$(( ($last_source_byte % $SECOND_SOURCE_BYTE_DIVIDEND) * 0X04 ))
	#echo "index in pading state 3 is: $index"
	result="$result${BASE64_CODE_TABLE[$index]}=";;
esac

str=$result

}

#main函数 $1输入文件 $2输出文件

echo "开始解密..."


   # 第二种


echo "-------------------"

get TSkr 0

read m

cat $1 |while read line

do
from=$line
echo "输入参数：$from"
base64_encode_string $from
# 写入文件
echo "$str" >> $2

done

echo "解密结束..."
}