如果您之所以问这个问题是因为您正在使用mkcert，那么诀窍在于.pem文件是cert和-key。Pem文件是密钥。

(你不需要转换，只需要运行mkcert yourdomain.dev otherdomain.dev)

先决条件

应该安装Openssl。 在Windows上，如果安装了Git Bash，试试!可以在这里找到替代二进制文件。

步骤1:从。pem中提取。key

openssl pkey -in cert.pem -out cert.key

步骤2:从。pem中提取。crt

openssl crl2pkcs7 -nocrl -certfile cert.pem | openssl pkcs7 -print_certs -out cert.crt

从pem文件中提取密钥和证书。

提取关键

openssl pkey -in foo.pem -out foo.key

另一种提取密钥的方法…

openssl rsa -in foo.pem -out foo.key

提取所有的证书，包括CA链

openssl crl2pkcs7 -nocrl -certfile foo.pem | openssl pkcs7 -print_certs -out foo.cert

将文本上的第一个证书提取为DER

openssl x509 -in foo.pem -outform DER -out first-cert.der

这是我在窗户上做的。

从谷歌下载一个包含open ssl exe的zip文件 解压zip文件并进入bin文件夹。 进入bin文件夹的地址栏，输入cmd。这将在此文件夹中打开命令提示符。 move/将pem文件放到bin文件夹中。 执行两条命令。一个创建证书，另一个创建密钥文件

openssl x509 -outform der -in yourPemFilename.pem -out certfileOutName.crt
openssl rsa -in yourPemFilename.pem -out keyfileOutName.key

.crt存储证书..pem格式。因此，.pem虽然也可以有其他东西，如csr(证书签名请求)、私钥、公钥或其他cert，但当它只存储一个cert时，它与.crt是一样的。

pem是一个base64编码的文件，每个部分之间有一个页眉和一个页脚。

要提取特定的部分，像下面这样的perl脚本是完全有效的，但是可以随意使用一些openssl命令。

 perl -ne "\$n++ if /BEGIN/; print if \$n == 1 && /BEGIN/.../END/;" mydomain.pem

其中==1可以更改为您需要的任何部分。显然，如果你确切地知道你需要的页眉和页脚，并且文件中只有其中一个(通常情况下，如果你只保留证书和密钥)，你可以简化它:

 perl -ne "print if /^-----BEGIN CERTIFICATE-----\$/.../END/;" mydomain.pem

使用OpenSSL转换

这些命令允许您将证书和密钥转换为不同的格式，以使它们与特定类型的服务器或软件兼容。

Convert a DER file (.crt .cer .der) to PEM openssl x509 -inform der -in certificate.cer -out certificate.pem Convert a PEM file to DER openssl x509 -outform der -in certificate.pem -out certificate.der Convert a PKCS#12 file (.pfx .p12) containing a private key and certificates to PEM openssl pkcs12 -in keyStore.pfx -out keyStore.pem -nodes You can add -nocerts to only output the private key or add -nokeys to only output the certificates. Convert a PEM certificate file and a private key to PKCS#12 (.pfx .p12) openssl pkcs12 -export -out certificate.pfx -inkey privateKey.key -in certificate.crt -certfile CACert.crt Convert PEM to CRT (.CRT file) openssl x509 -outform der -in certificate.pem -out certificate.crt

OpenSSL转换PEM

将PEM转换为DER Openssl x509 -outform der -in证书。导出certificate.der 将PEM转换为P7B Openssl crl2pkcs7 -nocrl -certfile证书。输出证书。p7b -certfile CACert.cer 将PEM转换为PFX Openssl pkcs12 -export -out证书。pfx -inkey privateKey。密钥输入证书。CACert.crt -certfile CACert.crt

OpenSSL Convert DER

将DER转换为PEM Openssl x509 -inform der -in证书。输出certificate.pem

OpenSSL转换P7B

将P7B转换为PEM Openssl pkcs7 -print_certs -in证书。P7b -out certificate.cer 将P7B转换为PFX Openssl pkcs7 -print_certs -in证书。P7b -out certificate.cer Openssl pkcs12 -export -in证书。-inkey privateKey。密钥输出证书。pfx -certfile CACert.cer

OpenSSL转换PFX

将PFX转换为PEM Openssl pkcs12 -in证书。PFX输出证书。cer节点

通过OpenSSL生成rsa密钥

Using OpenSSL on the command line you’d first need to generate a public and private key, you should password protect this file using the -passout argument, there are many different forms that this argument can take so consult the OpenSSL documentation about that. openssl genrsa -out private.pem 1024 This creates a key file called private.pem that uses 1024 bits. This file actually have both the private and public keys, so you should extract the public one from this file: openssl rsa -in private.pem -out public.pem -outform PEM -pubout or openssl rsa -in private.pem -pubout > public.pem or openssl rsa -in private.pem -pubout -out public.pem You’ll now have public.pem containing just your public key, you can freely share this with 3rd parties. You can test it all by just encrypting something yourself using your public key and then decrypting using your private key, first we need a bit of data to encrypt: Example file : echo 'too many secrets' > file.txt You now have some data in file.txt, lets encrypt it using OpenSSL and the public key: openssl rsautl -encrypt -inkey public.pem -pubin -in file.txt -out file.ssl This creates an encrypted version of file.txt calling it file.ssl, if you look at this file it’s just binary junk, nothing very useful to anyone. Now you can unencrypt it using the private key: openssl rsautl -decrypt -inkey private.pem -in file.ssl -out decrypted.txt You will now have an unencrypted file in decrypted.txt: cat decrypted.txt |output -> too many secrets

OpenSSL中的RSA TOOLS选项

NAME rsa - RSA key processing tool SYNOPSIS openssl rsa [-help] [-inform PEM|NET|DER] [-outform PEM|NET|DER] [-in filename] [-passin arg] [-out filename] [-passout arg] [-aes128] [-aes192] [-aes256] [-camellia128] [-camellia192] [-camellia256] [-des] [-des3] [-idea] [-text] [-noout] [-modulus] [-check] [-pubin] [-pubout] [-RSAPublicKey_in] [-RSAPublicKey_out] [-engine id] DESCRIPTION The rsa command processes RSA keys. They can be converted between various forms and their components printed out. Note this command uses the traditional SSLeay compatible format for private key encryption: newer applications should use the more secure PKCS#8 format using the pkcs8 utility. COMMAND OPTIONS -help Print out a usage message. -inform DER|NET|PEM This specifies the input format. The DER option uses an ASN1 DER encoded form compatible with the PKCS#1 RSAPrivateKey or SubjectPublicKeyInfo format. The PEM form is the default format: it consists of the DER format base64 encoded with additional header and footer lines. On input PKCS#8 format private keys are also accepted. The NET form is a format is described in the NOTES section. -outform DER|NET|PEM This specifies the output format, the options have the same meaning as the -inform option. -in filename This specifies the input filename to read a key from or standard input if this option is not specified. If the key is encrypted a pass phrase will be prompted for. -passin arg the input file password source. For more information about the format of arg see the PASS PHRASE ARGUMENTS section in openssl. -out filename This specifies the output filename to write a key to or standard output if this option is not specified. If any encryption options are set then a pass phrase will be prompted for. The output filename should not be the same as the input filename. -passout password the output file password source. For more information about the format of arg see the PASS PHRASE ARGUMENTS section in openssl. -aes128|-aes192|-aes256|-camellia128|-camellia192|-camellia256|-des|-des3|-idea These options encrypt the private key with the specified cipher before outputting it. A pass phrase is prompted for. If none of these options is specified the key is written in plain text. This means that using the rsa utility to read in an encrypted key with no encryption option can be used to remove the pass phrase from a key, or by setting the encryption options it can be use to add or change the pass phrase. These options can only be used with PEM format output files. -text prints out the various public or private key components in plain text in addition to the encoded version. -noout this option prevents output of the encoded version of the key. -modulus this option prints out the value of the modulus of the key. -check this option checks the consistency of an RSA private key. -pubin by default a private key is read from the input file: with this option a public key is read instead. -pubout by default a private key is output: with this option a public key will be output instead. This option is automatically set if the input is a public key. -RSAPublicKey_in, -RSAPublicKey_out like -pubin and -pubout except RSAPublicKey format is used instead. -engine id specifying an engine (by its unique id string) will cause rsa to attempt to obtain a functional reference to the specified engine, thus initialising it if needed. The engine will then be set as the default for all available algorithms. NOTES The PEM private key format uses the header and footer lines: -----BEGIN RSA PRIVATE KEY----- -----END RSA PRIVATE KEY----- The PEM public key format uses the header and footer lines: -----BEGIN PUBLIC KEY----- -----END PUBLIC KEY----- The PEM RSAPublicKey format uses the header and footer lines: -----BEGIN RSA PUBLIC KEY----- -----END RSA PUBLIC KEY----- The NET form is a format compatible with older Netscape servers and Microsoft IIS .key files, this uses unsalted RC4 for its encryption. It is not very secure and so should only be used when necessary. Some newer version of IIS have additional data in the exported .key files. To use these with the utility, view the file with a binary editor and look for the string "private-key", then trace back to the byte sequence 0x30, 0x82 (this is an ASN1 SEQUENCE). Copy all the data from this point onwards to another file and use that as the input to the rsa utility with the -inform NET option. EXAMPLES To remove the pass phrase on an RSA private key: openssl rsa -in key.pem -out keyout.pem To encrypt a private key using triple DES: openssl rsa -in key.pem -des3 -out keyout.pem To convert a private key from PEM to DER format: openssl rsa -in key.pem -outform DER -out keyout.der To print out the components of a private key to standard output: openssl rsa -in key.pem -text -noout To just output the public part of a private key: openssl rsa -in key.pem -pubout -out pubkey.pem Output the public part of a private key in RSAPublicKey format: openssl rsa -in key.pem -RSAPublicKey_out -out pubkey.pem