将pem键转换为ssh-rsa格式

Question

我有一个der格式的证书,从这个命令我生成一个公钥:

openssl x509 -inform der -in ejbcacert.cer -noout -pubkey > pub1key.pub

结果如下:

-----BEGIN PUBLIC KEY-----
MIGfMA0GCSqGSIb3DQEBAQUAA4GNADCBiQKBgQC7vbqajDw4o6gJy8UtmIbkcpnk
O3Kwc4qsEnSZp/TR+fQi62F79RHWmwKOtFmwteURgLbj7D/WGuNLGOfa/2vse3G2
eHnHl5CB8ruRX9fBl/KgwCVr2JaEuUm66bBQeP5XeBotdR4cvX38uPYivCDdPjJ1
QWPdspTBKcxeFbccDwIDAQAB
-----END PUBLIC KEY-----

我怎样才能获得这样的公钥？来自证书还是来自这个公钥？

ssh-rsa AAAAB3NzaC1yc2EAAAADAQABAAAAgQC7vbqajDw4o6gJy8UtmIbkcpnkO3Kwc4qsEnSZp/TR+fQi62F79RHWmwKOtFmwteURgLbj7D/WGuNLGOfa/2vse3G2eHnHl5CB8ruRX9fBl/KgwCVr2JaEuUm66bBQeP5XeBotdR4cvX38uPYivCDdPjJ1QWPdspTBKcxeFbccDw==

这是通过以下命令获得的:

ssh-keygen -y -f private_key1.pem > public_key1.pub

Answer 1

不需要编译东西.您也可以这样做ssh-keygen:

ssh-keygen -f pub1key.pub -i

将从openssl格式读取公钥pub1key.pub并以OpenSSH格式输出.

注意:在某些情况下,您需要指定输入格式:

ssh-keygen -f pub1key.pub -i -mPKCS8

来自ssh-keygen文档(来自man ssh-keygen):

-m key_format指定-i(导入)或-e(导出)转换选项的密钥格式.支持的密钥格式为:"RFC4716"(RFC 4716/SSH2公钥或私钥),"PKCS8"(PEM PKCS8公钥)或"PEM"(PEM公钥).默认转换格式为"RFC4716".

Answer 2

不需要脚本或其他"技巧":openssl并且ssh-keygen足够了.我假设密钥没有密码(这很糟糕).

生成RSA对

以下所有方法都以相同的格式提供RSA密钥对

1. 用openssl(man genrsa)

   openssl genrsa -out dummy-genrsa.pem 2048
   

   在OpenSSL v1.0.1 genrsa 被取代,genpkey所以这是新方法(man genpkey):

   openssl genpkey -algorithm RSA -out dummy-genpkey.pem -pkeyopt rsa_keygen_bits:2048
   

2. 用ssh-keygen

   ssh-keygen -t rsa -b 2048 -f dummy-ssh-keygen.pem -N '' -C "Test Key"
   

将DER转换为PEM

如果您有DER格式的RSA密钥对,您可能希望将其转换为PEM以允许以下格式转换:

代:

openssl genpkey -algorithm RSA -out genpkey-dummy.cer -outform DER -pkeyopt rsa_keygen_bits:2048

转换:

openssl rsa -inform DER -outform PEM -in genpkey-dummy.cer -out dummy-der2pem.pem

从PEM格式的RSA对中提取公钥

2. 采用PEM格式:

   openssl rsa -in dummy-xxx.pem -pubout
   

3. 在OpenSSH v2格式中,请参阅:

   ssh-keygen -y -f dummy-xxx.pem
   

笔记

操作系统和软件版本:

[user@test1 ~]# cat /etc/redhat-release ; uname -a ; openssl version
CentOS release 6.5 (Final)
Linux test1.example.local 2.6.32-431.el6.x86_64 #1 SMP Fri Nov 22 03:15:09 UTC 2013 x86_64 x86_64 x86_64 GNU/Linux
OpenSSL 1.0.1e-fips 11 Feb 2013

参考文献:

• Sysmic.org在GnuPG,OpenSsh和OpenSSL之间转换密钥

Answer 3

要回答我自己的问题,在openssl邮件列表上发帖后得到了这个:

这是从OpenSSL公钥转换为OpenSSH公钥的C代码.您可以从此链接获取代码并自行编译:

static unsigned char pSshHeader[11] = { 0x00, 0x00, 0x00, 0x07, 0x73, 0x73, 0x68, 0x2D, 0x72, 0x73, 0x61};

static int SshEncodeBuffer(unsigned char *pEncoding, int bufferLen, unsigned char* pBuffer)
{
   int adjustedLen = bufferLen, index;
   if (*pBuffer & 0x80)
   {
      adjustedLen++;
      pEncoding[4] = 0;
      index = 5;
   }
   else
   {
      index = 4;
   }
   pEncoding[0] = (unsigned char) (adjustedLen >> 24);
   pEncoding[1] = (unsigned char) (adjustedLen >> 16);
   pEncoding[2] = (unsigned char) (adjustedLen >>  8);
   pEncoding[3] = (unsigned char) (adjustedLen      );
   memcpy(&pEncoding[index], pBuffer, bufferLen);
   return index + bufferLen;
}

int main(int argc, char**  argv)
{
   int iRet = 0;
   int nLen = 0, eLen = 0;
   int encodingLength = 0;
   int index = 0;
   unsigned char *nBytes = NULL, *eBytes = NULL;
   unsigned char* pEncoding = NULL;
   FILE* pFile = NULL;
   EVP_PKEY *pPubKey = NULL;
   RSA* pRsa = NULL;
   BIO *bio, *b64;

   ERR_load_crypto_strings(); 
   OpenSSL_add_all_algorithms();

   if (argc != 3)
   {
      printf("usage: %s public_key_file_name ssh_key_description\n", argv[0]);
      iRet = 1;
      goto error;
   }

   pFile = fopen(argv[1], "rt");
   if (!pFile)
   {
      printf("Failed to open the given file\n");
      iRet = 2;
      goto error;
   }

   pPubKey = PEM_read_PUBKEY(pFile, NULL, NULL, NULL);
   if (!pPubKey)
   {
      printf("Unable to decode public key from the given file: %s\n", ERR_error_string(ERR_get_error(), NULL));
      iRet = 3;
      goto error;
   }

   if (EVP_PKEY_type(pPubKey->type) != EVP_PKEY_RSA)
   {
      printf("Only RSA public keys are currently supported\n");
      iRet = 4;
      goto error;
   }

   pRsa = EVP_PKEY_get1_RSA(pPubKey);
   if (!pRsa)
   {
      printf("Failed to get RSA public key : %s\n", ERR_error_string(ERR_get_error(), NULL));
      iRet = 5;
      goto error;
   }

   // reading the modulus
   nLen = BN_num_bytes(pRsa->n);
   nBytes = (unsigned char*) malloc(nLen);
   BN_bn2bin(pRsa->n, nBytes);

   // reading the public exponent
   eLen = BN_num_bytes(pRsa->e);
   eBytes = (unsigned char*) malloc(eLen);
   BN_bn2bin(pRsa->e, eBytes);

   encodingLength = 11 + 4 + eLen + 4 + nLen;
   // correct depending on the MSB of e and N
   if (eBytes[0] & 0x80)
      encodingLength++;
   if (nBytes[0] & 0x80)
      encodingLength++;

   pEncoding = (unsigned char*) malloc(encodingLength);
   memcpy(pEncoding, pSshHeader, 11);

   index = SshEncodeBuffer(&pEncoding[11], eLen, eBytes);
   index = SshEncodeBuffer(&pEncoding[11 + index], nLen, nBytes);

   b64 = BIO_new(BIO_f_base64());
   BIO_set_flags(b64, BIO_FLAGS_BASE64_NO_NL);
   bio = BIO_new_fp(stdout, BIO_NOCLOSE);
   BIO_printf(bio, "ssh-rsa ");
   bio = BIO_push(b64, bio);
   BIO_write(bio, pEncoding, encodingLength);
   BIO_flush(bio);
   bio = BIO_pop(b64);
   BIO_printf(bio, " %s\n", argv[2]);
   BIO_flush(bio);
   BIO_free_all(bio);
   BIO_free(b64);

error:
   if (pFile)
      fclose(pFile);
   if (pRsa)
      RSA_free(pRsa);
   if (pPubKey)
      EVP_PKEY_free(pPubKey);
   if (nBytes)
      free(nBytes);
   if (eBytes)
      free(eBytes);
   if (pEncoding)
      free(pEncoding);

   EVP_cleanup();
   ERR_free_strings();
   return iRet;
}

Answer 4

所有错误的答案.这是正确的:

ssh-keygen -i -m PKCS8 -f public-key.pem

Answer 5

以下脚本将获取 base64 编码的 DER 格式的 ci.jenkins-ci.org 公钥证书并将其转换为 OpenSSH 公钥文件。此代码假定使用了 2048 位 RSA 密钥，并从 Ian Boyd's answer 中汲取了很多。我已经在 Jenkins wiki 中对这篇文章的评论中解释了它是如何工作的。

echo -n "ssh-rsa " > jenkins.pub
curl -sfI https://ci.jenkins-ci.org/ | grep -i X-Instance-Identity | tr -d \\r | cut -d\  -f2 | base64 -d | dd bs=1 skip=32 count=257 status=none | xxd -p -c257 | sed s/^/00000007\ 7373682d727361\ 00000003\ 010001\ 00000101\ / | xxd -p -r | base64 -w0 >> jenkins.pub
echo >> jenkins.pub

Answer 6

ssh-keygen -f private.pem -y > public.pub

Answer 7

我做了

ssh-keygen -i -f $ sshkeysfile >> authorized_keys

信用就在这里