AES (aes-cbc-256) encryption/decryption openssl 预期输出被截断

Question

我写了一个脚本。请原谅我不是脚本专家。解密后，结果被截断了。

[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？

这里是加密：

    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

下面是解密(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-parameters 不能包含二进制零。可能的过滤器修复：

#!/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：----

我认为你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]"' ""
}

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

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

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

Answer 2

关注你的问题，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，您必须使用 -p 来告诉 xxd 这是一个普通的十六进制字符串（没有换行符）。

当使用 xxd -p 转换回十六进制时，每 32 个字节添加一次换行符。不幸的是，xxd 没有提供不包括换行符的标志（您可以使用 -c 来设置列数，但它被限制为最大数量）。有很多选项可以删除换行符，但一个选项是在您的命令中附加 | 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"

AES (aes-cbc-256) encryption/decryption openssl 预期输出被截断

AES (aes-cbc-256) encryption/decryption with openssl expected output truncated

bash

openssl

aes

cbc-mode