题
我有证书 der
格式,使用此命令我生成一个公钥:
openssl x509 -inform der -in ejbcacert.cer -noout -pubkey > pub1key.pub
结果是这样的:
-----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?来自证书或此公共密钥?
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
解决方案 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;
}
其他提示
无需编译内容。您可以使用 ssh-keygen
:
ssh-keygen -f pub1key.pub -i
将从 pub1key.pub
读取openssl格式的公钥,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 docs(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”。
不需要脚本或其他“技巧”: openssl
和 ssh-keygen
就足够了。我假设密钥没有密码(这很糟糕)。
生成 RSA 对
以下所有方法均给出相同格式的 RSA 密钥对
使用 openssl (曼根萨)
openssl genrsa -out dummy-genrsa.pem 2048
在 OpenSSL v1.0.1 中
genrsa
被取代 经过genpkey
所以这是新的方法(曼·根普基):openssl genpkey -algorithm RSA -out dummy-genpkey.pem -pkeyopt rsa_keygen_bits:2048
使用 ssh 密钥生成器
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,您可能需要将其转换为 PEM 以允许以下格式转换:
一代:
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
PEM 格式:
openssl rsa -in dummy-xxx.pem -pubout
OpenSSH v2 格式 看:
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:
所有错误的答案。这是正确的:
ssh-keygen -i -m PKCS8 -f public-key.pem
ssh-keygen -f private.pem -y > public.pub
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。这段代码假设使用了一个2048位的RSA密钥,并从这个Ian Boyd的答案。我已经在这篇文章的评论中解释了它的工作原理在詹金斯维基。
echo -n "ssh-rsa " > jenkins.pub
curl -sfI https://ci.jenkins-ci.org/ | grep 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
FWIW,这个BASH脚本将采用PEM或DER格式的X.509证书或OpenSSL公钥文件(也是PEM格式)作为第一个参数并输出OpenSSH RSA公钥。这扩展了@ mkalkov上面的答案。要求是 cat
, grep
, tr
, dd
, xxd
, sed
, xargs
, file
, uuidgen
, base64
, openssl
(1.0+),当然还有 bash
。所有除 openssl
(包含 base64
)以外的所有内容都可以保证在任何现代Linux系统上都是基本安装的一部分,除了 xxd
(其中Fedora显示在 vim-common
包中。如果有人想要清理并使其更好,请告知lector。
#!/bin/bash
#
# Extract a valid SSH format public key from an X509 public certificate.
#
# Variables:
pubFile=$1
fileType="no"
pkEightTypeFile="$pubFile"
tmpFile="/tmp/`uuidgen`-pkEightTypeFile.pk8"
# See if a file was passed:
[ ! -f "$pubFile" ] && echo "Error, bad or no input file $pubFile." && exit 1
# If it is a PEM format X.509 public cert, set $fileType appropriately:
pemCertType="X$(file $pubFile | grep 'PEM certificate')"
[ "$pemCertType" != "X" ] && fileType="PEM"
# If it is an OpenSSL PEM-format PKCS#8-style public key, set $fileType appropriately:
pkEightType="X$(grep -e '-BEGIN PUBLIC KEY-' $pubFile)"
[ "$pkEightType" != "X" ] && fileType="PKCS"
# If this is a file we can't recognise, try to decode a (binary) DER-format X.509 cert:
if [ "$fileType" = "no" ]; then
openssl x509 -in $pubFile -inform DER -noout
derResult=$(echo $?)
[ "$derResult" = "0" ] && fileType="DER"
fi
# Exit if not detected as a file we can use:
[ "$fileType" = "no" ] && echo "Error, input file not of type X.509 public certificate or OpenSSL PKCS#8-style public key (not encrypted)." && exit 1
# Convert the X.509 public cert to an OpenSSL PEM-format PKCS#8-style public key:
if [ "$fileType" = "PEM" -o "$fileType" = "DER" ]; then
openssl x509 -in $pubFile -inform $fileType -noout -pubkey > $tmpFile
pkEightTypeFile="$tmpFile"
fi
# Build the string:
# Front matter:
frontString="$(echo -en 'ssh-rsa ')"
# Encoded modulus and exponent, with appropriate pointers:
encodedModulus="$(cat $pkEightTypeFile | grep -v -e "----" | tr -d '\n' | 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 )"
# Add a comment string based on the filename, just to be nice:
commentString=" $(echo $pubFile | xargs basename | sed -e 's/\.crt\|\.cer\|\.pem\|\.pk8\|\.der//')"
# Give the user a string:
echo $frontString $encodedModulus $commentString
# cleanup:
rm -f $tmpFile