API module for public key infrastructure.


This module provides functions to handle public key infrastructure from RFC 3280 - X.509 certificates (will later be upgraded to RFC 5280) and some parts of the PKCS-standard. Currently this application is mainly used by the new ssl implementation. The API is yet under construction and only a few of the functions are currently documented and thereby supported.



All records used in this manual are generated from asn1 specifications and are documented in the User's Guide. See Public key records and X.509 Certificate records.

Use the following include directive to get access to the records and constant macros described here and in the User's Guide.


Data Types

boolean() = true | false

string = [bytes()]

asn1_der_encoded() = binary() | [bytes()]

der_bin() = binary()

oid() - a tuple of integers as generated by the asn1 compiler.

public_key() = rsa_public_key() | dsa_public_key()

rsa_public_key() = #'RSAPublicKey'{}

rsa_private_key() = #'RSAPrivateKey'{}

dsa_public_key() = integer()

public_key_params() = dsa_key_params()

dsa_key_params() = #'Dss-Parms'{}

private_key() = rsa_private_key() | dsa_private_key()

rsa_private_key() = #'RSAPrivateKey'{}

dsa_private_key() = #'DSAPrivateKey'{}

x509_certificate() = "#Certificate{}"

x509_tbs_certificate() = #'TBSCertificate'{}


decode_private_key(KeyInfo) ->
decode_private_key(KeyInfo, Password) -> {ok, PrivateKey} | {error, Reason}


KeyInfo = {KeyType, der_bin(), ChipherInfo}
As returned from pem_to_der/1 for private keys
KeyType = rsa_private_key | dsa_private_key
ChipherInfo = opaque() | no_encryption
ChipherInfo may contain encryption parameters if the private key is password protected, these are opaque to the user just pass the value returned by pem_to_der/1 to this function.
Password = string()
Must be specified if CipherInfo =/= no_encryption
PrivateKey = private_key()
Reason = term()

Decodes an asn1 der encoded private key.

pem_to_der(File) -> {ok, [Entry]}


File = path()
Password = string()
Entry = {entry_type(), der_bin(), CipherInfo}
ChipherInfo = opaque() | no_encryption
ChipherInfo may contain encryption parameters if the private key is password protected, these will be handled by the function decode_private_key/2.
entry_type() = cert | cert_req | rsa_private_key | dsa_private_key | dh_params

Reads a PEM file and translates it into its asn1 der encoded parts.

pkix_decode_cert(Cert, Type) -> {ok, DecodedCert} | {error, Reason}


Cert = asn1_der_encoded()
Type = plain | otp
DecodeCert = x509_certificate()
When type is specified as otp the asn1 spec OTP-PKIX.asn1 is used to decode known extensions and enhance the signature field in #'Certificate'{} and '#TBSCertificate'{}. This is currently used by the new ssl implementation but not documented and supported for the public_key application.
Reason = term()

Decodes an asn1 encoded pkix certificate.