RSA私钥和公钥文件格式 (pkcs#1, pkcs#8, pkcs#12, pem)

约定不等于承诺〃 2022-05-30 06:55 337阅读 0赞

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   <th style="border-color:rgb(153,170,243);padding:4px;">Format</th> 
   <th style="border-color:rgb(153,170,243);padding:4px;">Name</th> 
   <th style="border-color:rgb(153,170,243);padding:4px;">Description</th> 
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   <td style="border-color:rgb(153,170,243);padding:4px;">PKCS #7</td> 
   <td style="border-color:rgb(153,170,243);padding:4px;">Cryptographic Message Syntax Standard</td> 
   <td style="border-color:rgb(153,170,243);padding:4px;">A PKCS #7 file can be used to store certificates, which is a SignedData structure without data (just the certificates). The file name extension is usually&nbsp;<code style="font-size:14px;line-height:22px;">.p7b</code>,&nbsp;<code style="font-size:14px;line-height:22px;">.p7c</code></td> 
  </tr> 
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   <td style="border-color:rgb(153,170,243);padding:4px;">PKCS #8</td> 
   <td style="border-color:rgb(153,170,243);padding:4px;">Private-Key Information Syntax Standard.</td> 
   <td style="border-color:rgb(153,170,243);padding:4px;">Used to carry private certificate keypairs (encrypted or unencrypted).</td> 
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   <td style="border-color:rgb(153,170,243);padding:4px;">PKCS #12</td> 
   <td style="border-color:rgb(153,170,243);padding:4px;">Personal Information Exchange Syntax Standard.</td> 
   <td style="border-color:rgb(153,170,243);padding:4px;">Defines a file format commonly used to store private keys with accompanying public key certificates, protected with a password-based symmetric key. It is the successor to PFX from Microsoft.</td> 
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   <td style="border-color:rgb(153,170,243);padding:4px;">DER</td> 
   <td style="border-color:rgb(153,170,243);padding:4px;">Distinguished Encoding Rules</td> 
   <td style="border-color:rgb(153,170,243);padding:4px;">A binary format for keys or certificates. It is a message transfer syntax specified by the ITU in X.690.</td> 
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   <td style="border-color:rgb(153,170,243);padding:4px;">PEM</td> 
   <td style="border-color:rgb(153,170,243);padding:4px;">Privacy Enhanced Mail</td> 
   <td style="border-color:rgb(153,170,243);padding:4px;">Base64 encoded DER certificates or keys, with additional header and footer lines.&nbsp;<br><br>The PEM private key format uses the header and footer lines:&nbsp;<br><code style="font-size:14px;line-height:22px;">-----BEGIN RSA PRIVATE KEY-----</code>&nbsp;<br><code style="font-size:14px;line-height:22px;">-----END RSA PRIVATE KEY-----</code>&nbsp;<br><br>The PEM public key format uses the header and footer lines:&nbsp;<br><code style="font-size:14px;line-height:22px;">-----BEGIN PUBLIC KEY-----</code>&nbsp;<br><code style="font-size:14px;line-height:22px;">-----END PUBLIC KEY-----</code>&nbsp;<br><br>The PEM certificate uses the header and footer lines:&nbsp;<br><code style="font-size:14px;line-height:22px;">-----BEGIN CERTIFICATE-----</code>&nbsp;<br><code style="font-size:14px;line-height:22px;">-----END CERTIFICATE-----</code>&nbsp;</td> 
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</table>

### RSA Public Key file (PKCS\#1) ###

The RSA Public key PEM file is specific for RSA keys.

It starts and ends with the tags:

-----BEGIN RSA PUBLIC KEY-----
    BASE64 ENCODED DATA
    -----END RSA PUBLIC KEY-----

Within the base64 encoded data the following DER structure is present:

RSAPublicKey ::= SEQUENCE {
        modulus           INTEGER,  -- n
        publicExponent    INTEGER   -- e
    }

###  ###

### Public Key file (PKCS\#8) ###

Because RSA is not used exclusively inside X509 and SSL/TLS, a more generic key format is available in the form of PKCS\#8, that identifies the type of public key and contains the relevant data.

It starts and ends with the tags:

-----BEGIN PUBLIC KEY-----
    BASE64 ENCODED DATA
    -----END PUBLIC KEY-----

Within the base64 encoded data the following DER structure is present:

PublicKeyInfo ::= SEQUENCE {
      algorithm       AlgorithmIdentifier,
      PublicKey       BIT STRING
    }
    
    AlgorithmIdentifier ::= SEQUENCE {
      algorithm       OBJECT IDENTIFIER,
      parameters      ANY DEFINED BY algorithm OPTIONAL
    }

So for an RSA public key, the OID is 1.2.840.113549.1.1.1 and there is a RSAPublicKey as the PublicKey key data bitstring.

###  ###

### RSA Private Key file (PKCS\#1) ###

The RSA private key PEM file is specific for RSA keys.

It starts and ends with the tags:

-----BEGIN RSA PRIVATE KEY-----
    BASE64 ENCODED DATA
    -----END RSA PRIVATE KEY-----

Within the base64 encoded data the following DER structure is present:

RSAPrivateKey ::= SEQUENCE {
      version           Version,
      modulus           INTEGER,  -- n
      publicExponent    INTEGER,  -- e
      privateExponent   INTEGER,  -- d
      prime1            INTEGER,  -- p
      prime2            INTEGER,  -- q
      exponent1         INTEGER,  -- d mod (p-1)
      exponent2         INTEGER,  -- d mod (q-1)
      coefficient       INTEGER,  -- (inverse of q) mod p
      otherPrimeInfos   OtherPrimeInfos OPTIONAL
    }

### Private Key file (PKCS\#8) ###

Because RSA is not used exclusively inside X509 and SSL/TLS, a more generic key format is available in the form of PKCS\#8, that identifies the type of private key and contains the relevant data.

The unencrypted PKCS\#8 encoded data starts and ends with the tags:

-----BEGIN PRIVATE KEY-----
    BASE64 ENCODED DATA
    -----END PRIVATE KEY-----

Within the base64 encoded data the following DER structure is present:

PrivateKeyInfo ::= SEQUENCE {
      version         Version,
      algorithm       AlgorithmIdentifier,
      PrivateKey      BIT STRING
    }
    
    AlgorithmIdentifier ::= SEQUENCE {
      algorithm       OBJECT IDENTIFIER,
      parameters      ANY DEFINED BY algorithm OPTIONAL
    }

So for an RSA private key, the OID is 1.2.840.113549.1.1.1 and there is a RSAPrivateKey as the PrivateKey key data bitstring.

The encrypted PKCS\#8 encoded data start and ends with the tags:

-----BEGIN ENCRYPTED PRIVATE KEY-----
    BASE64 ENCODED DATA
    -----END ENCRYPTED PRIVATE KEY-----

Within the base64 encoded data the following DER structure is present:

EncryptedPrivateKeyInfo ::= SEQUENCE {
      encryptionAlgorithm  EncryptionAlgorithmIdentifier,
      encryptedData        EncryptedData
    }
    
    EncryptionAlgorithmIdentifier ::= AlgorithmIdentifier
    
    EncryptedData ::= OCTET STRING

The EncryptedData OCTET STRING is a PKCS\#8 PrivateKeyInfo (see above).