RFC 5958 Asymmetric Key Packages

RFC 5959 Algorithms for Asymmetric Key Package Content Type

秘密鍵 (Private Key) の保存から公開鍵を含むことができる形式に変更された

RFC 5911 New ASN.1 Modules for Cryptographic Message Syntax (CMS) and S/MIME

RFC 5912 New ASN.1 Modules for the Public Key Infrastructure Using X.509 (PKIX)

code:OneAsymmetricKey

AsymmetricKeyPackage ::= SEQUENCE SIZE (1..MAX) Of OneAsymmetricKey

OneAsymmetricKey ::= SEQUENCE {

version Version,

privateKeyAlgorithm PrivateKeyAlgorithmIdentifier,

privateKey PrivateKey,

...,

...

}

PrivateKeyInfo ::= OneAsymmetricKey

Version ::= INTEGER { v1(0), v2(1) } (v1, ..., v2)

PrivateKeyAlgorithmIdentifier ::= AlgorithmIdentifier

{ PUBLIC-KEY,

{ PrivateKeyAlgorithms } }

PrivateKey ::= OCTET STRING

PublicKey ::= BIT STRING

AsymmetricKeyPackage として一覧をSEQUENCE で保存できるようだ

公開鍵(publicKey)と私有鍵(privateKey)はOCTET STRING とBIT STRINGで区別されているが、並び順とタグでも区別したほうがいいだろう。

code:EncryptedPrivateKeyInfo

EncryptedPrivateKeyInfo ::= SEQUENCE {

encryptionAlgorithm EncryptionAlgorithmIdentifier,

encryptedData EncryptedData }

EncryptionAlgorithmIdentifier ::= AlgorithmIdentifier

{ CONTENT-ENCRYPTION,

{ KeyEncryptionAlgorithms } }

EncryptedData ::= OCTET STRING

暗号化する場合、 EncryptedPrivateKeyInfo に PrivateKeyInfo をASN.1 BER または DER で EncryptedData として格納する

PUBLIC-KEY, CONTENT-ENCRYPTION などはclassで RFC 5911 にあるようだ

SoftLibASN1でXMLっぽく書き出して型などを足してみた例 (XERではない 鍵は新規生成で未使用のもの)

code:EncryptedPrivateKeyInfo XML

<?xml version="1.0" encoding="UTF-8" standalone="no"?>

<SEQUENCE>

<SEQUENCE type="EncryptionAlgorithmIdentifier" name="encryptionAlgorithm">

<OBJECTIDENTIFIER name="algorithm" short="id-PBES2">1.2.840.113549.1.5.13</OBJECTIDENTIFIER>

<SEQUENCE type="PBES2-params" name="parameters">

<SEQUENCE name="keyDerivationFunc" type="PBES2-KDFs,AlgorithmIdentifier">

<OBJECTIDENTIFIER name="algorithm" short="id-PBKDF2">1.2.840.113549.1.5.12</OBJECTIDENTIFIER>

<SEQUENCE type="PBKDF2-params" name="parameters">

<OCTETSTRING>pKC4rdTapqslzz1EtjuCBg==</OCTETSTRING>

<INTEGER>2048</INTEGER>

<SEQUENCE type="AlgorithmIdeitifier">

<OBJECTIDENTIFIER short="id-hmacWithSHA256">1.2.840.113549.2.9</OBJECTIDENTIFIER>

<NULL/>

</SEQUENCE>

</SEQUENCE>

</SEQUENCE>

<SEQUENCE name="encrytionScheme" type="AlogrithmIdentifier">

<OBJECTIDENTIFIER name="algorithm" short="aes256-CBC-PAD">2.16.840.1.101.3.4.1.42</OBJECTIDENTIFIER>

<OCTETSTRING name="parameters">DzfbpLQiCuS8WLoZRGnWug==</OCTETSTRING>

</SEQUENCE>

</SEQUENCE>

</SEQUENCE>

<OCTETSTRING name="encryptedData">YiRsfS7bv4PQYuD1Z4LwfWdCIME6NNi73GEiD4kNKR9jgjYXdq6sUZcZpZwoj3E0/mgFHJI1HZc107ybm2jLrRZmbvP8Sz0bs0LUVFTrDwBWNnN2HQ8AF6rfQnJjsH9w1jg9LTZKz68SoUvKYEJU0Uu0mDmR3/2VNYAJaAno3dY663LiwziWrCGbAM50QXCx</OCTETSTRING>

</SEQUENCE>

PBES2のパラメータ内にPBKDF2のパラメータ( salt, iterationCount, hmac AlgorithmIdentifierr)と暗号種別、salt (IV)、本体はencryptedData