public_key
API module for public key infrastructure.
This module provides functions to handle public key infrastructure. It can encode/decode different file formats (PEM, openssh), sign and verify digital signatures and validate certificate paths and certificate revocation lists.
public_key
- public_key requires the crypto and asn1 applications, the latter since R16 (hopefully the runtime dependency on asn1 will be removed again in the future).
- Supports
RFC 5280 - Internet X.509 Public Key Infrastructure Certificate and Certificate Revocation List (CRL) Profile - Supports
PKCS-1 - RSA Cryptography Standard - Supports
DSS - Digital Signature Standard (DSA - Digital Signature Algorithm) - Supports
PKCS-3 - Diffie-Hellman Key Agreement Standard - Supports
PKCS-5 - Password-Based Cryptography Standard - Supports
PKCS-8 - Private-Key Information Syntax Standard - Supports
PKCS-10 - Certification Request Syntax Standard
COMMON DATA TYPES
Note!
All records used in this manual are generated from ASN.1 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.
-include_lib("public_key/include/public_key.hrl").
Data Types
oid() - a tuple of integers as generated by the ASN1 compiler.
boolean() = true | false
string() = [bytes()]
der_encoded() = binary()
pki_asn1_type() = 'Certificate' | 'RSAPrivateKey'| 'RSAPublicKey' |
'DSAPrivateKey' | 'DSAPublicKey' | 'DHParameter' |
'SubjectPublicKeyInfo' | 'PrivateKeyInfo' |
'CertificationRequest' | 'ECPrivateKey' | 'EcpkParameters'
pem_entry () = {pki_asn1_type(), binary(), %% DER or encrypted DER
not_encrypted | cipher_info()}
cipher_info() = {"RC2-CBC | "DES-CBC" | "DES-EDE3-CBC",
crypto:rand_bytes(8)} | 'PBES2-params'}
public_key() = rsa_public_key() | dsa_public_key() | ec_public_key()
private_key() = rsa_private_key() | dsa_private_key() | ec_private_key()
rsa_public_key() = #'RSAPublicKey'{}
rsa_private_key() = #'RSAPrivateKey'{}
dsa_public_key() = {integer(), #'Dss-Parms'{}}
dsa_private_key() = #'DSAPrivateKey'{}
ec_public_key() = {#'ECPoint'{}, #'EcpkParameters'{} |
{namedCurve, oid()}}
ec_private_key() = #'ECPrivateKey'{}
public_crypt_options() = [{rsa_pad, rsa_padding()}].
rsa_padding() = 'rsa_pkcs1_padding' | 'rsa_pkcs1_oaep_padding' |
'rsa_no_padding'
rsa_digest_type() = 'md5' | 'sha' | 'sha224' | 'sha256' | 'sha384' |
'sha512'
dss_digest_type() = 'sha'
ecdsa_digest_type() = 'sha'| 'sha224' | 'sha256' | 'sha384' | 'sha512'
crl_reason() = unspecified | keyCompromise | cACompromise |
affiliationChanged | superseded | cessationOfOperation |
certificateHold | privilegeWithdrawn | aACompromise
ssh_file() = openssh_public_key | rfc4716_public_key | known_hosts |
auth_keys
Functions
compute_key(OthersKey, MyKey)->
compute_key(OthersKey, MyKey, Params)->
OthersKey = #'ECPoint'{} | binary(), MyKey = #'ECPrivateKey'{} | binary()
Params = #'DHParameter'{}
Compute shared secret
decrypt_private(CipherText, Key) -> binary()
decrypt_private(CipherText, Key, Options) -> binary()
CipherText = binary()
Key = rsa_private_key()
Options = public_crypt_options()
Public key decryption using the private key. See also crypto:private_decrypt/4
decrypt_public(CipherText, Key) - > binary()
decrypt_public(CipherText, Key, Options) - > binary()
CipherText = binary()
Key = rsa_public_key()
Options = public_crypt_options()
Public key decryption using the public key. See also crypto:public_decrypt/4
der_decode(Asn1type, Der) -> term()
Asn1Type = atom()
Der = der_encoded()
Decodes a public key ASN.1 DER encoded entity.
der_encode(Asn1Type, Entity) -> der_encoded()
Asn1Type = atom()
Entity = term()
Asn1Type
Encodes a public key entity with ASN.1 DER encoding.
generate_key(Params) -> {Public::binary(), Private::binary()} | #'ECPrivateKey'{}
Params = #'DHParameter'{} | {namedCurve, oid()} | #'ECParameters'{}
Generates a new keypair
pem_decode(PemBin) -> [pem_entry()]
PemBin = binary()
Decode PEM binary data and return entries as ASN.1 DER encoded entities.
pem_encode(PemEntries) -> binary()
PemEntries = [pem_entry()]
Creates a PEM binary
pem_entry_decode(PemEntry) -> term()
pem_entry_decode(PemEntry, Password) -> term()
PemEntry = pem_entry()
Password = string()
Decodes a PEM entry. pem_decode/1 returns a list of PEM entries. Note that if the PEM entry is of type 'SubjectPublickeyInfo' it will be further decoded to an rsa_public_key() or dsa_public_key().
pem_entry_encode(Asn1Type, Entity) -> pem_entry()
pem_entry_encode(Asn1Type, Entity, {CipherInfo, Password}) -> pem_entry()
Asn1Type = pki_asn1_type()
Entity = term()
CipherInfo = cipher_info()
Password = string()
Asn1Type
. If Asn1Type
is 'SubjectPublicKeyInfo'
then Entity
must be either an rsa_public_key() or a
dsa_public_key() and this function will create the appropriate
'SubjectPublicKeyInfo' entry.
Creates a PEM entry that can be feed to pem_encode/1.
encrypt_private(PlainText, Key) -> binary()
PlainText = binary()
Key = rsa_private_key()
Public key encryption using the private key. See also crypto:private_encrypt/4
encrypt_public(PlainText, Key) -> binary()
PlainText = binary()
Key = rsa_public_key()
Public key encryption using the public key. See also crypto:public_encrypt/4
pkix_decode_cert(Cert, otp|plain) -> #'Certificate'{} | #'OTPCertificate'{}
Cert = der_encoded()
Decodes an ASN.1 DER encoded PKIX certificate. The otp option will use the customized ASN.1 specification OTP-PKIX.asn1 for decoding and also recursively decode most of the standard parts.
pkix_encode(Asn1Type, Entity, otp | plain) -> der_encoded()
Asn1Type = atom()
Entity = #'Certificate'{} | #'OTPCertificate'{} | a valid subtype
DER encodes a PKIX x509 certificate or part of such a certificate. This function must be used for encoding certificates or parts of certificates that are decoded/created in the otp format, whereas for the plain format this function will directly call der_encode/2.
pkix_is_issuer(Cert, IssuerCert) -> boolean()
Cert = der_encode() | #'OTPCertificate'{}
IssuerCert = der_encode() | #'OTPCertificate'{}
Checks if IssuerCert
issued Cert
pkix_is_fixed_dh_cert(Cert) -> boolean()
Cert = der_encode() | #'OTPCertificate'{}
Checks if a Certificate is a fixed Diffie-Hellman Cert.
pkix_is_self_signed(Cert) -> boolean()
Cert = der_encode() | #'OTPCertificate'{}
Checks if a Certificate is self signed.
pkix_issuer_id(Cert, IssuedBy) -> {ok, IssuerID} | {error, Reason}
Cert = der_encode() | #'OTPCertificate'{}
IssuedBy = self | other
IssuerID = {integer(), {rdnSequence, [#'AttributeTypeAndValue'{}]}}
Reason = term()
Returns the issuer id.
pkix_normalize_name(Issuer) -> Normalized
Issuer = {rdnSequence,[#'AttributeTypeAndValue'{}]}
Normalized = {rdnSequence, [#'AttributeTypeAndValue'{}]}
Normalizes a issuer name so that it can be easily compared to another issuer name.
pkix_path_validation(TrustedCert, CertChain, Options) -> {ok, {PublicKeyInfo, PolicyTree}} | {error, {bad_cert, Reason}}
TrustedCert = #'OTPCertificate'{} | der_encode() | unknown_ca | selfsigned_peer
CertChain = [der_encode()]
Options = proplists:proplist()
PublicKeyInfo = {?'rsaEncryption' | ?'id-dsa', rsa_public_key() | integer(), 'NULL' | 'Dss-Parms'{}}
PolicyTree = term()
Reason = cert_expired | invalid_issuer | invalid_signature | unknown_ca | selfsigned_peer | name_not_permitted | missing_basic_constraint | invalid_key_usage | crl_reason()
unknown_ca
or selfsigned_peer
that can be discovered while
constructing the input to this function and that should be run through the verify_fun
.
Performs a basic path validation according to
verify_fun
Available options are:
The fun should be defined as:
fun(OtpCert :: #'OTPCertificate'{},
Event :: {bad_cert, Reason :: atom()} |
{extension, #'Extension'{}},
InitialUserState :: term()) ->
{valid, UserState :: term()} |
{valid_peer, UserState :: term()} |
{fail, Reason :: term()} |
{unknown, UserState :: term()}.
If the verify callback fun returns {fail, Reason}, the
verification process is immediately stopped. If the verify
callback fun returns {valid, UserState}, the verification
process is continued, this can be used to accept specific path
validation errors such as selfsigned_peer
as well as
verifying application specific extensions. If called with an
extension unknown to the user application the return value
{unknown, UserState} should be used.
max_path_length
is the maximum number of non-self-issued
intermediate certificates that may follow the peer certificate
in a valid certification path. So if max_path_length
is 0 the PEER must
be signed by the trusted ROOT-CA directly, if 1 the path can
be PEER, CA, ROOT-CA, if it is 2 PEER, CA, CA, ROOT-CA and so
on.
pkix_crls_validate(OTPCertificate, DPAndCRLs, Options) -> CRLStatus()
OTPCertificate = #'OTPCertificate'{}
DPAndCRLs = [{DP::#'DistributionPoint'{} ,CRL::#'CertificateList'{}}]
Options = proplists:proplist()
CRLStatus() = valid | {bad_cert, revocation_status_undetermined} | {bad_cert, {revoked, crl_reason()}}
Performs CRL validation. It is intended to be called from the verify fun of pkix_path_validation/3
Available options are:
The fun has the following type spec:
fun(#'DistributionPoint'{}, #'CertificateList'{}) ->
#'CertificateList'{}
The fun should use the information in the distribution point to acesses the lates possible version of the CRL. If this fun is not specified public_key will use the default implementation:
fun(_DP, CRL) -> CRL end
The fun has the following type spec:
fun(#'DistributionPoint'{}, #'CertificateList'{},
{rdnSequence,[#'AttributeTypeAndValue'{}]}, term()) ->
{ok, #'OTPCertificate'{}, [der_encoded]}
The fun should return the root certificate and certificate chain that has signed the CRL.
fun(DP, CRL, Issuer, UserState) -> {ok, RootCert, CertChain}
pkix_sign(#'OTPTBSCertificate'{}, Key) -> der_encode()
Key = rsa_public_key() | dsa_public_key()
Signs a 'OTPTBSCertificate'. Returns the corresponding der encoded certificate.
pkix_sign_types(AlgorithmId) -> {DigestType, SignatureType}
AlgorithmId = oid()
DigestType = rsa_digest_type() | dss_digest_type()
SignatureType = rsa | dsa
Translates signature algorithm oid to erlang digest and signature types.
pkix_verify(Cert, Key) -> boolean()
Cert = der_encode()
Key = rsa_public_key() | dsa_public_key()
Verify PKIX x.509 certificate signature.
sign(Msg, DigestType, Key) -> binary()
Msg = binary() | {digest,binary()}
DigestType = rsa_digest_type() | dss_digest_type() | ecdsa_digest_type()
Key = rsa_private_key() | dsa_private_key() | ec_private_key()
Creates a digital signature.
ssh_decode(SshBin, Type) -> [{public_key(), Attributes::list()}]
SshBin = binary()
Type = public_key | ssh_file()
Type
is public_key
the binary may be either
a rfc4716 public key or a openssh public key.Decodes a ssh file-binary. In the case of know_hosts or auth_keys the binary may include one or more lines of the file. Returns a list of public keys and their attributes, possible attribute values depends on the file type represented by the binary.
ssh_encode([{Key, Attributes}], Type) -> binary()
Key = public_key()
Attributes = list()
Type = ssh_file()
Encodes a list of ssh file entries (public keys and attributes) to a binary. Possible attributes depends on the file type, see ssh_decode/2
verify(Msg, DigestType, Signature, Key) -> boolean()
Msg = binary() | {digest,binary()}
DigestType = rsa_digest_type() | dss_digest_type() | ecdsa_digest_type()
Signature = binary()
Key = rsa_public_key() | dsa_public_key() | ec_public_key()
Verifies a digital signature