1. RSA Key的生成
生成2048 bit的私钥
$ openssl genrsa -out Key0.pem -f4 2048Generating RSA private key, 2048 bit long modulus....................................+++.................................+++e is 65537 (0x10001)
$ cat Key0.pem
-----BEGIN RSA PRIVATE KEY-----MIIEowIBAAKCAQEA1IJ2tHYgAQ9/SbGPgc/pgAq/gfcp/HsOpJyQgOTBMWbD6CBz
BJh4FzxP+RuJflOm7ILXc3QOO+ccJIT/6P8yuRp4JgWnd8r5wvAwBCzYrRV8zz6Y
tgbBO7ORtd/lPtHzdLXj52/aAbrRu4L8qu3C8acOrM6EjY6nKUdtbYRhm2VssSE5
ApU3pPKW6/QYXrUGypj8E8pujtYbtQIir4OXpMzJ2+AYeZOvjqSTuDSvet2As3qj
BdpBTXWfNC44FHAolcWI6U8Q/L6QKO2H8P11IZAA8aHZva2vudcxVwKz2QiOR1yV
ey4iXk2BhbOJQxC0XT3cc8k7Pbr+BHCDjR7i8wIDAQABAoIBAQCHlsJUfDYJVzD4
/SC6S8UJHFJ6gxA39vAt2XNduhcGBTKkLegVG48sDCBeqdI9VvRfXVBIatkWIWxU
ZMO/jux3LEtSvzLN/SUE2ylX0KFjNh2PQbpAEelCxV0H9VYYke7LHa7PIQ+xINjm0jmSeedzNgrn+VCb3VQMw3UvdlKsyYx6j2AKx4qmML2T6qhwn/racKqTArH/9I2h
y47cxZYYACWwMD4R4NVj/UVy1yc4JU0HrtgyIo9fZL2CpGx/ZxQ0fKBGa5pI3xmn
TZZzbTUy3SGORijr1R5dYe48ZnxYc7n4G7/E9aiytrvDuny3b4crPu2UAyqsDfBK
j8ercULpAoGBAPqeKEC9J+hMGy4U1Ssu5ZqaNXxvLUEfT/ge+s/iVdh/dCtYEeqh
iR8MFJ7cqGUZt/ecR9remF/xGdXob0YssfaZiBEYu8mgr5mR4/xhF15fJHTmuyla
K3xsjOpMYTcF5KGQdwNnIXfodgL58xbel0ksx70qS/OOH60XF30Oe5KFAoGBANkS
y79dRokQDVqMDIPNswfxA7kFteL6wgXXnVgTqTCDZm7L3TnTBxwj5ZETxUm0RuA/FdY46L54eiWcOpHcdMlKyf4Re9H855/25bUQf28e7LLRciuGUCZxNRKQ6r3IIERi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-----END RSA PRIVATE KEY-----123456789101112131415161718192021222324252627282930313233
由于-inform和-outform的默认参数为PEM,所以这里的完整命令为:
$ openssl genrsa -outform=PEM -out Key0.pem -f4 2048 1
从私钥导出公钥
$ openssl rsa -in Key0.pem -pubout -out Key0_pub.pem
writing RSA key$ cat Key0_pub.pem
-----BEGIN PUBLIC KEY-----
MIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIBCgKCAQEA1IJ2tHYgAQ9/SbGPgc/p
gAq/gfcp/HsOpJyQgOTBMWbD6CBzBJh4FzxP+RuJflOm7ILXc3QOO+ccJIT/6P8y
uRp4JgWnd8r5wvAwBCzYrRV8zz6YtgbBO7ORtd/lPtHzdLXj52/aAbrRu4L8qu3C8acOrM6EjY6nKUdtbYRhm2VssSE5ApU3pPKW6/QYXrUGypj8E8pujtYbtQIir4OX
pMzJ2+AYeZOvjqSTuDSvet2As3qjBdpBTXWfNC44FHAolcWI6U8Q/L6QKO2H8P11
IZAA8aHZva2vudcxVwKz2QiOR1yVey4iXk2BhbOJQxC0XT3cc8k7Pbr+BHCDjR7i8wIDAQAB
-----END PUBLIC KEY-----123456789101112
2. RSA Key的转换
在用openssl rsa命令生成RSA Key时有3种可选格式,分别为PEM,DER和NET,通过-inform参数指定,默认为PEM。
- DER: 原始的RSA Key按照ASN1 DER编码的方式存储
- PEM: DER经过base64编码转换为PEM格式
- NET: OpenSSL的帮助提示显示,NET是一个同老式的Netscape server和微软IIS .key文件兼容的格式(不过我没有详细研究过这种格式)
除了上面提到的3种格式外,最常见的还有可读性较好的文本格式,这里称为TXT格式。以下是PEM,DER和TXT格式之间的相互转换。
2.1 PEM转DER格式
直接通过openssl rsa进行输入格式和输出格式的转换。
# 私钥:PEM --(convert)--> DER$ openssl rsa -inform PEM -in Key0.pem -outform DER -out Key0.der$# 公钥:PEM --(convert)> DER$ openssl rsa -inform PEM -in Key0_pub.pem -pubin -outform DER -out Key0_pub.der12345
既然PEM是DER格式进行base64编码的格式,那PEM通过base64解码应为DER格式:
# 私钥:PEM --(decryption)--> DER$ openssl base64 -d -in Key0.pem -out Key0.bin$# 公钥:PEM --(decryption)--> DER$ openssl base64 -d -in Key0_pub.pem -out Key0_pub.bin12345
比较以上两种方法生成的文件Key0.der和Key0.bin,以及Key0_pub.der和Key0_pub.bin,其md5sum的结果一样,说明内容一样:
$ md5sum Key0.der Key0.bin Key0_pub.der Key0_pub.bin f6fa3ec1e35866578fccd507cb106f08 Key0.derf6fa3ec1e35866578fccd507cb106f08 Key0.binfd15765f1656cc3332992cf6e979217f Key0_pub.derfd15765f1656cc3332992cf6e979217f Key0_pub.bin12345
2.2 DER转PEM格式
跟PEM转DER格式一样,可以通过openssl rsa命令和openssl base64命令进行转换。
使用openssl rsa命令转换:
# 私钥:DER --(convert)--> PEM$ openssl rsa -inform DER -in Key0.der -outform PEM -out Key0.PEM $# 公钥:DER --(convert)--> PEM$ openssl rsa -inform DER -in Key0_pub.der -pubin -outform PEM -out Key0_pub.PEM12345
使用openssl base64命令转换:
# 私钥:DER --(encryption)--> PEM$ openssl base64 -e -in Key0.der -out Key0.pem$# 公钥:DER --(encryption)--> PEM$ openssl base64 -e -in Key0_pub.der -out Key0_pub.pem12345
以下是两种转换方式得到的内容,略有不同。
$ cat Key0_pub.PEM
-----BEGIN PUBLIC KEY-----
MIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIBCgKCAQEA1IJ2tHYgAQ9/SbGPgc/p
gAq/gfcp/HsOpJyQgOTBMWbD6CBzBJh4FzxP+RuJflOm7ILXc3QOO+ccJIT/6P8y
uRp4JgWnd8r5wvAwBCzYrRV8zz6YtgbBO7ORtd/lPtHzdLXj52/aAbrRu4L8qu3C8acOrM6EjY6nKUdtbYRhm2VssSE5ApU3pPKW6/QYXrUGypj8E8pujtYbtQIir4OX
pMzJ2+AYeZOvjqSTuDSvet2As3qjBdpBTXWfNC44FHAolcWI6U8Q/L6QKO2H8P11
IZAA8aHZva2vudcxVwKz2QiOR1yVey4iXk2BhbOJQxC0XT3cc8k7Pbr+BHCDjR7i8wIDAQAB
-----END PUBLIC KEY-----
$ cat Key0_pub.pem
MIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIBCgKCAQEA1IJ2tHYgAQ9/SbGPgc/p
gAq/gfcp/HsOpJyQgOTBMWbD6CBzBJh4FzxP+RuJflOm7ILXc3QOO+ccJIT/6P8y
uRp4JgWnd8r5wvAwBCzYrRV8zz6YtgbBO7ORtd/lPtHzdLXj52/aAbrRu4L8qu3C8acOrM6EjY6nKUdtbYRhm2VssSE5ApU3pPKW6/QYXrUGypj8E8pujtYbtQIir4OX
pMzJ2+AYeZOvjqSTuDSvet2As3qjBdpBTXWfNC44FHAolcWI6U8Q/L6QKO2H8P11
IZAA8aHZva2vudcxVwKz2QiOR1yVey4iXk2BhbOJQxC0XT3cc8k7Pbr+BHCDjR7i8wIDAQAB123456789101112131415161718
其唯一不同的后者Key0_pub.pem是通过openssl base64命令得到的文件,丢失了”-----BEGIN PUBLIC KEY-----“和”-----END PUBLIC KEY-----“这两条注释信息。
2.3 PEM转TXT格式
直接通过openssl rsa命令的-text参数输出可读的TXT格式:
# 私钥:PEM --> TXT$ openssl rsa -inform PEM -in Key0.PEM -text -out Key0.txt$# 公钥:PEM --> TXT$ openssl rsa -inform PEM -in Key0_pub.PEM -pubin -text -out Key0_pub.txt12345
实践发现,转换为TXT的PEM文件需要包含”-----BEGIN PUBLIC KEY-----“和”-----END PUBLIC KEY-----“标记,没有这个标记转换会失败。
例如,以下将DER通过openssl base64命令加密为PEM格式后,再尝试转换为TXT格式失败。
$ openssl rsa -inform PEM -in Key0.pem -text -out Key0.txt
unable to load Private Key140185959843488:error:0906D06C:PEM routines:PEM_read_bio:no start line:pem_lib.c:703:Expecting: ANY PRIVATE KEY
$ cat Key0.pem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kWOL7i8O8qeyP3wC1yiXSynM0aUXAoGAW3i+WGKx3idpBDi2VTyY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7181920212223242526272829
对比这里的key0.pem可最初生成的内容,唯一的差别就是这里缺少”-----BEGIN PUBLIC KEY-----“和”-----END PUBLIC KEY-----“标记
2.4 TXT转PEM格式
我不知道如何用openssl命令进行转换,谁知道的告诉我啊~~~
但是,我相信看过TXT内容的都应该知道如何进行转换,因为TXT文件最后的”-----BEGIN PUBLIC KEY-----“和”-----END PUBLIC KEY-----“部分就是PEM内容。
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