使用OpenSSL签名的消息; 无法用Android Java验证

Question

我正在使用SHA256和RSA使用OpenSSL在我的Ubuntu机器上签名.我的目标是使用Android的Java在Android上验证此消息.

以下命令在ubuntu上使用:

openssl genrsa -out private.pem 1024 
openssl rsa -in private.pem -out public.pem -outform PEM -pubout
echo 'foobar' > data.txt
openssl dgst -sha256 < data.txt > hash
openssl rsautl -sign -inkey private.pem -keyform PEM -in hash  > signature
openssl rsa -in private_key.pem -pubout -outform DER -out public_key.der
openssl enc -base64 -in signature -out base64_signature

我现在已经创建了密钥,对消息进行了签名,为公钥创建了一个.der文件,该文件应该能够在Java中访问并使用Base64对消息进行编码.然后我将.der公钥放在我的设备上,并成功将密钥加载到PublicKey类中.

此方法用于验证消息:

public static boolean verify(PublicKey publicKey,String data,String verification){
    java.security.Signature sig;
    try {
        sig = java.security.Signature.getInstance("SHA256WithRSA");
        sig.initVerify(publicKey);
        try {
            sig.update(verification.getBytes());
        } catch (Exception e) {
            ...
        }

        if (!sig.verify(Base64.decode(data, Base64.DEFAULT))) {
            return false;
        }
        return true;
    }
    catch ....
    return false;
}

调用方法时的参数:

verify(PublicKey, Base64 encoded data in a String that is to be verified, "foobar");

显然验证失败了,但我不明白为什么.我猜它必须对编码做些什么(？).

---

更新!所以我设法将结果写入Base64.decode(data, Base64.DEFAULT))文件,并使用hexeditor将其与原始签名文件进行比较.完全不同!

Answer 1

Java生成并期望以稍微不同的形式接收签名.消息的哈希必须用DER编码,然后用PKCS#1填充,然后用私钥签名.Openssl有一个命令(因为它实际上是一个标准程序).代替

openssl dgst -sha256 < data.txt > hash
openssl rsautl -sign -inkey private.pem -keyform PEM -in hash  > signature

你做

openssl dgst -sha256 -binary -sign private.pem data.txt > signature

另请注意:

• 你的data.txt包含换行符,不要忘记它在String verification变量中
• sig.update(verification.getBytes())应该明确指出一个字符集 - 用于填充data.txt文件的相同字符集,例如:sig.update(verification.getBytes("UTF-8"))

其余的命令/代码似乎没问题.

UPD - 回答关于差异的@GilCol:

两个签名消息(PKCS#1)的填充相同.但消息是不同的.

当你使用时openssl dgst -sha256 < data.txt > hash,hash将包含(取决于openssl版本):

(stdin)= aec070645fe53ee3b3763059376134f058cc337247c978add178b6ccdfb0019f

要么

aec070645fe53ee3b3763059376134f058cc337247c978add178b6ccdfb0019f

它只是纯文本,它是您将使用的消息openssl rsautl -sign ....我们可以看到openssl rsautl -verify ...:

# raw message as-is - we can see the padding
$ openssl rsautl -in signature -pubin -inkey public.pem -verify -raw -hexdump
0000 - 00 01 ff ff ff ff ff ff-ff ff ff ff ff ff ff ff   ................
0010 - ff ff ff ff ff ff ff ff-ff ff ff ff ff ff ff ff   ................
0020 - ff ff ff ff ff ff ff ff-ff ff ff ff ff ff ff ff   ................
0030 - ff ff ff ff ff ff ff ff-ff ff ff ff ff ff ff ff   ................
0040 - ff ff ff ff ff ff ff ff-ff ff ff ff ff ff ff ff   ................
0050 - ff ff ff ff ff ff ff ff-ff ff ff ff ff ff ff ff   ................
0060 - ff ff ff ff ff ff ff ff-ff ff ff ff ff ff ff ff   ................
0070 - ff ff ff ff ff ff ff ff-ff ff ff ff ff ff ff ff   ................
0080 - ff ff ff ff ff ff ff ff-ff ff ff ff ff ff ff ff   ................
0090 - ff ff ff ff ff ff ff ff-ff ff ff ff ff ff ff ff   ................
00a0 - ff ff ff ff ff ff ff ff-ff ff ff ff ff ff ff ff   ................
00b0 - ff ff ff ff ff ff ff ff-ff ff ff ff ff ff 00 61   ...............a #
00c0 - 65 63 30 37 30 36 34 35-66 65 35 33 65 65 33 62   ec070645fe53ee3b #
00d0 - 33 37 36 33 30 35 39 33-37 36 31 33 34 66 30 35   3763059376134f05 # your plain-text message
00e0 - 38 63 63 33 33 37 32 34-37 63 39 37 38 61 64 64   8cc337247c978add #
00f0 - 31 37 38 62 36 63 63 64-66 62 30 30 31 39 66 0a   178b6ccdfb0019f. # we can even see newline char (0a) at the end

# strip the padding
$ openssl rsautl -in signature -pubin -inkey public.pem -verify -pkcs -hexdump
0000 - 61 65 63 30 37 30 36 34-35 66 65 35 33 65 65 33   aec070645fe53ee3
0010 - 62 33 37 36 33 30 35 39-33 37 36 31 33 34 66 30   b3763059376134f0
0020 - 35 38 63 63 33 33 37 32-34 37 63 39 37 38 61 64   58cc337247c978ad
0030 - 64 31 37 38 62 36 63 63-64 66 62 30 30 31 39 66   d178b6ccdfb0019f
0040 - 0a                                                .

如果您使用openssl dgst -sha256 -binary < data.txt > hash以二进制(纯)形式获取哈希值,然后对其进行签名,则结果会更好,但仍然不正确:

# raw message as-is - we can see the same padding
$ openssl rsautl -in signature -pubin -inkey public.pem -verify -raw -hexdump
0000 - 00 01 ff ff ff ff ff ff-ff ff ff ff ff ff ff ff   ................
0010 - ff ff ff ff ff ff ff ff-ff ff ff ff ff ff ff ff   ................
0020 - ff ff ff ff ff ff ff ff-ff ff ff ff ff ff ff ff   ................
0030 - ff ff ff ff ff ff ff ff-ff ff ff ff ff ff ff ff   ................
0040 - ff ff ff ff ff ff ff ff-ff ff ff ff ff ff ff ff   ................
0050 - ff ff ff ff ff ff ff ff-ff ff ff ff ff ff ff ff   ................
0060 - ff ff ff ff ff ff ff ff-ff ff ff ff ff ff ff ff   ................
0070 - ff ff ff ff ff ff ff ff-ff ff ff ff ff ff ff ff   ................
0080 - ff ff ff ff ff ff ff ff-ff ff ff ff ff ff ff ff   ................
0090 - ff ff ff ff ff ff ff ff-ff ff ff ff ff ff ff ff   ................
00a0 - ff ff ff ff ff ff ff ff-ff ff ff ff ff ff ff ff   ................
00b0 - ff ff ff ff ff ff ff ff-ff ff ff ff ff ff ff ff   ................
00c0 - ff ff ff ff ff ff ff ff-ff ff ff ff ff ff ff ff   ................
00d0 - ff ff ff ff ff ff ff ff-ff ff ff ff ff ff ff 00   ................
00e0 - ae c0 70 64 5f e5 3e e3-b3 76 30 59 37 61 34 f0   ..pd_.>..v0Y7a4. # the hash - now in binary form
00f0 - 58 cc 33 72 47 c9 78 ad-d1 78 b6 cc df b0 01 9f   X.3rG.x..x...... #

# strip the padding
$ openssl rsautl -in signature -pubin -inkey public.pem -verify -pkcs -hexdump
0000 - ae c0 70 64 5f e5 3e e3-b3 76 30 59 37 61 34 f0   ..pd_.>..v0Y7a4. # just the hash, nothing else
0010 - 58 cc 33 72 47 c9 78 ad-d1 78 b6 cc df b0 01 9f   X.3rG.x..x...... #

但是当你使用时openssl dgst -sha256 -sign ...,消息是不同的 - 它现在是消息摘要(散列)的标准ASN.1结构.让我们来看看:

# raw message as-is - we can see the same padding
$ openssl rsautl -in signature -pubin -inkey public.pem -verify -raw -hexdump
0000 - 00 01 ff ff ff ff ff ff-ff ff ff ff ff ff ff ff   ................
0010 - ff ff ff ff ff ff ff ff-ff ff ff ff ff ff ff ff   ................
0020 - ff ff ff ff ff ff ff ff-ff ff ff ff ff ff ff ff   ................
0030 - ff ff ff ff ff ff ff ff-ff ff ff ff ff ff ff ff   ................
0040 - ff ff ff ff ff ff ff ff-ff ff ff ff ff ff ff ff   ................
0050 - ff ff ff ff ff ff ff ff-ff ff ff ff ff ff ff ff   ................
0060 - ff ff ff ff ff ff ff ff-ff ff ff ff ff ff ff ff   ................
0070 - ff ff ff ff ff ff ff ff-ff ff ff ff ff ff ff ff   ................
0080 - ff ff ff ff ff ff ff ff-ff ff ff ff ff ff ff ff   ................
0090 - ff ff ff ff ff ff ff ff-ff ff ff ff ff ff ff ff   ................
00a0 - ff ff ff ff ff ff ff ff-ff ff ff ff ff ff ff ff   ................
00b0 - ff ff ff ff ff ff ff ff-ff ff ff ff ff ff ff ff   ................
00c0 - ff ff ff ff ff ff ff ff-ff ff ff ff 00 30 31 30   .............010 #
00d0 - 0d 06 09 60 86 48 01 65-03 04 02 01 05 00 04 20   ...`.H.e.......  # the message - it's different
00e0 - ae c0 70 64 5f e5 3e e3-b3 76 30 59 37 61 34 f0   ..pd_.>..v0Y7a4. # <- we can see the hash (in binary form) starting at this line
00f0 - 58 cc 33 72 47 c9 78 ad-d1 78 b6 cc df b0 01 9f   X.3rG.x..x...... #

# strip the padding
$ openssl rsautl -in signature -pubin -inkey public.pem -verify -pkcs -hexdump
0000 - 30 31 30 0d 06 09 60 86-48 01 65 03 04 02 01 05   010...`.H.e.....
0010 - 00 04 20 ae c0 70 64 5f-e5 3e e3 b3 76 30 59 37   .. ..pd_.>..v0Y7
0020 - 61 34 f0 58 cc 33 72 47-c9 78 ad d1 78 b6 cc df   a4.X.3rG.x..x...
0030 - b0 01 9f                                          ...

# parse the message and show the underlying ASN.1 structure
$ openssl rsautl -in signature -pubin -inkey public.pem -verify -pkcs -asn1parse 
    0:d=0  hl=2 l=  49 cons: SEQUENCE          
    2:d=1  hl=2 l=  13 cons:  SEQUENCE          
    4:d=2  hl=2 l=   9 prim:   OBJECT            :sha256               # type of hash
   15:d=2  hl=2 l=   0 prim:   NULL              
   17:d=1  hl=2 l=  32 prim:  OCTET STRING      
      0000 - ae c0 70 64 5f e5 3e e3-b3 76 30 59 37 61 34 f0   ..pd_.>..v0Y7a4. # the hash in binary form
      0010 - 58 cc 33 72 47 c9 78 ad-d1 78 b6 cc df b0 01 9f   X.3rG.x..x...... # and no extra newline chars

如您所见,只有最后一个signature文件具有正确的ASN.1结构,前两个只是"一些任意"消息,使用RSA私钥签名.