Question

我写了一个剧本。请原谅我不是脚本专家。解密后，结果被截断。

[Message in text]: 0123456789abcdefghijklmnopqrstuvwxyz

message_input in hex: 303132333435363738396162636465666768696a6b6c6d6e6f707172737475767778797a0a
key: 788a1ca0bf1ab80f092841aabd77793f
hex string is too short, padding with zero bytes to length
c19f83afc1160ce81b0fc9906d513693386ccdd313b0f2884c698411441054e8
ciphered text: c19f83afc1160ce81b0fc9906d513693386ccdd313b0f2884c698411441054e8
IV: 7ecd3d63a8b74bb2f80d71a1c9d43359
deciphering ...

hex string is too short, padding with zero bytes to length
key: 788a1ca0bf1ab80f092841aabd77793f
iv: 7ecd3d63a8b74bb2f80d71a1c9d43359
answer: 30313233343536373839616263646566
Deciphered Message in hex: 30313233343536373839616263646566
deciphered text: 0123456789abcdef

恢复的deciphered text: 0123456789abcdef，ghijklmnopqrstuvwxyz被截断。这应该是AES-CBC。有没有我没有打开的选项？

这是加密方式：

    IV=$(openssl rand -hex 16)
    get_key_for_ciphering; # key_for_ciphering gets populated

    message_input=$(echo -n "${message_input//[[:space:]]/}") # remove spaces

    echo "message_input in hex: "$message_input
    echo "key": $key_for_ciphering;

    ANS=$(echo "0: $message_input" | xxd -r | openssl enc -aes-256-cbc -iv $IV -K "$key_for_ciphering" | xxd -p)

    ANS=$(echo -n "${ANS//[[:space:]]/}") # remove spaces

这是解密（message_input = $ ANS）：

    get_key_for_ciphering; # key_for_ciphering gets populated

    ANS=$(echo "0: $message_input" | xxd -r | openssl enc -aes-256-cbc -d -nopad -nosalt -K "$key_for_ciphering" -iv $IV | xxd -p) # -nopad -nosalt

Answer 1

----编辑：----

不起作用，因为shell参数不能包含二进制零。过滤器可能的解决方法：

#!/bin/bash

tohex () {
    perl -e 'binmode STDIN; while (<STDIN>) { print unpack "H*",$_; }'
}

fromhex () {
    perl -e 'binmode STDIN; while (<STDIN>) { print pack "H*",$_; }'
}

binInput='0123456789abcdefghijklmnopqrstuvwxyz'

hexIV="$(openssl rand -hex 16)"

hexKey='788a1ca0bf1ab80f092841aabd77793f'

hexCipher="$(printf '%s' "$binInput" |\
    openssl enc -aes-256-cbc -nosalt -iv "$hexIV" -K "$hexKey" | tohex)"

binResult="$(printf '%s' "$hexCipher" | fromhex |\
   openssl enc -aes-256-cbc -d -iv "$hexIV" -K "$hexKey")"

if [ "$binInput" = "$binResult" ]; then echo OK;
fi

----原文：----

我认为您的问题出在十六进制转换上。尝试使用perl pack / unpack：

tohex () {
    perl -e 'print unpack "H*", "$ARGV[0]"' "$1"
}

fromhex () {
    perl -e 'print pack "H*", "$ARGV[0]"' "$1"
}

message='0123456789abcdefghijklmnopqrstuvwxzy §"+!%/=()'
message_hex=$(tohex "$message")
message_cmp=$(fromhex "$message_hex")

if [ "$message" = "$message_cmp" ]; then echo OK; fi

Answer 2

在您的问题中，问题出在xxd命令中。当使用xxd -r将十六进制字符串转换为二进制时，必须使用-p来告诉xxd这是一个普通的十六进制字符串（无换行符）。

使用xxd -p转换回十六进制时，每32个字节添加一个换行符。不幸的是，xxd没有提供不包含换行符的标志（您可以使用-c来设置列数，但是它被限制为最大数目）。删除换行符的选项很多，但其中一个是在命令后附加| tr -d '\n'，如下例所示。

IV=$(openssl rand -hex 16)
key_for_ciphering=$(openssl rand -hex 16)
message_input="303132333435363738396162636465666768696a6b6c6d6e6f707172737475767778797a0a"

message_input=$(echo -n "${message_input//[[:space:]]/}") # remove spaces

echo "Message: $message_input"
echo "Key: $key_for_ciphering"
echo "IV: $IV"

ANS=$(echo "0: $message_input" | xxd -r -p | openssl enc -aes-256-cbc -iv $IV -K "$key_for_ciphering" | xxd -p | tr -d '\n')

ANS=$(echo -n "${ANS//[[:space:]]/}") # remove spaces

echo "Encrypted: $ANS"

ANS=$(echo "0: $ANS" | xxd -r -p | openssl enc -aes-256-cbc -d -nopad -nosalt -K "$key_for_ciphering" -iv $IV | xxd -p | tr -d '\n')

echo "Decrypted: $ANS"

带有OpenSSL的AES（AES-CBC-256）加密/解密预期输出被截断

2 个答案: