View Source public_key (public_key v1.16.3)
API module for public-key infrastructure.
Provides functions to handle public-key infrastructure, for details see public_key application.
Note
All records used in this Reference Manual are generated from ASN.1 specifications and are documented in the User's Guide. See Public-key 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").
Summary
Types: Common
ASN.1 type present in the Public Key applications ASN.1 specifications.
ASN.1 DER encoded entity.
Hash function used to create a message digest
Object identifier, a tuple of integers as generated by the ASN.1
compiler.
Types: Keys
Can be provided together with a custom private key, that specifies a key fun, to provide additional options understood by the fun.
ASN.1 defined private key format for the DSA algorithm.
ASN.1 defined public key format for the DSA algorithm.
ASN.1 defined public key format for the DSS algorithm (part of DSA key).
ASN.1 defined private key format for the ECDSA algorithm.
ASN.1 defined public key format for the ECDSA algorithm.
ASN.1 defined private key format for the EDDSA algorithm, possible oids: ?'id-Ed25519' | ?'id-Ed448'
ASN.1 defined public key format for the EDDSA algorithm, possible oids: ?'id-Ed25519' | ?'id-Ed448'
ASN.1 defined parameters for public key algorithms.
Supported private keys
Supported public keys
ASN.1 defined private key format plain RSA algorithm or customization fun.
ASN.1 defined private key format the RSSASSA-PSS algorithm or customization fun.
ASN.1 defined public key format for the RSSASSA-PSS algorithm.
ASN.1 defined public key format for plain RSA algorithm.
Types: PEM files
Possible Ciphers
are "RC2-CBC" | "DES-CBC" | "DES-EDE3-CBC" Salt
could be generated with
crypto:strong_rand_bytes(8)
.
ASN.1 type that can be found in PEM files that can be decode by the public_key application.
Types: Certificates
The reason that a certifcate gets rejected by the certificate path validation.
An encoded or decode certificate.
A certificate is identified by its serial-number and Issuer Name.
A record that can be used to provide the certificate on both the DER encoded and the OTP decode format.
The value of the issuer part of a certificate.
Certificate policy information.
Information a certificates public key.
Types: Certificate Revocation
The reason that a certifcate has been revoked as define by RFC 5280.
Types: Test Data
Options to customize generated test certificates
Certificate customize options for diffrent parts of the certificate test chain.
Configuration options for the generated certificate test chain.
PEM API
Decodes PEM binary data and returns entries as ASN.1 DER encoded entities.
Creates a PEM binary.
Equivalent to pem_entry_decode(PemEntry, "")
.
Decodes a PEM entry. pem_decode/1
returns a list of PEM
entries. Notice that if the PEM entry is of type 'SubjectPublickeyInfo', it is
further decoded to an rsa_public_key/0
or dsa_public_key/0
.
Equivalent to pem_entry_encode/3
.
Creates a PEM entry that can be feed to pem_encode/1
.
Key API
Computes shared secret.
Computes shared secret.
Selects a group for Diffie-Hellman key exchange with the key size in the range
MinSize...MaxSize
and as close to SuggestedSize
as possible. If
Groups == undefined
a default set will be used, otherwise the group is
selected from Groups
.
Generates a new key pair. Note that except for Diffie-Hellman the public key is
included in the private key structure. See also crypto:generate_key/2
Sign/Verify API
Signs an 'OTPTBSCertificate'. Returns the corresponding DER-encoded certificate.
Verifies PKIX x.509 certificate signature.
Equivalent to sign(Msg, DigestType, Key, [])
.
Creates a digital signature.
Verifies a digital signature.
Certificate API
Clears any loaded CA certificates, returns true if any was loaded.
Returns the trusted CA certificates if any are loaded, otherwise uses
cacerts_load/0
to load them. The function fails if no cacerts
could be
loaded.
Loads the OS supplied trusted CA certificates.
Loads the trusted CA certificates from a file.
Decodes an ASN.1 DER-encoded PKIX certificate.
DER encodes a PKIX x509 certificate or part of such a certificate.
Translates OID to Erlang digest type
Checks if a certificate is a fixed Diffie-Hellman certificate.
Checks if IssuerCert
issued Cert
.
Checks if a certificate is self-signed.
Returns the x509 certificate issuer id, if it can be determined.
Normalizes an issuer name so that it can be easily compared to another issuer name.
Performs a basic path validation according to RFC 5280.
Translates signature algorithm OID to Erlang digest and signature types.
Returns the X509 certificate subject id.
Equivalent to pkix_verify_hostname(Cert, ReferenceIDs, [])
.
This function checks that the Presented Identifier (e.g hostname) in a peer certificate is in agreement with at least one of the Reference Identifier that the client expects to be connected to.
The return value of calling this function is intended to be used in the
match_fun
option in pkix_verify_hostname/3
.
Certificate Revocation API
Returns the issuer of the CRL
.
Verify that Cert
is the CRL
signer.
Performs CRL validation. It is intended to be called from the verify fun of pkix_path_validation/3 .
Creates a distribution point for CRLs issued by the same issuer as Cert
. Can
be used as input to pkix_crls_validate/3
Extracts distribution points from the certificates extensions.
Checks whether the given distribution point matches the Issuing Distribution Point of the CRL, as described in RFC 5280.
Perform OCSP response validation according to RFC 6960. Returns {'ok', Details} when OCSP response is successfully validated and {error, {bad_cert, Reason}} otherwise.
Generates a short hash of an issuer name. The hash is returned as a string containing eight hexadecimal digits.
ASN.1 Encoding API
Decodes a public-key ASN.1 DER encoded entity.
Encodes a public-key entity with ASN.1 DER encoding.
Test Data API
Creates certificate configuration(s) consisting of certificate and its private key plus CA certificate bundle, for a client and a server, intended to facilitate automated testing of applications using X509-certificates, often through SSL/TLS. The test data can be used when you have control over both the client and the server in a test scenario.
Generates a root certificate that can be used in multiple calls to
pkix_test_data/1
when you want the same root certificate for several generated
certificates.
Legacy RSA Encryption API
Public-key decryption using the private key. See also crypto:private_decrypt/4
Public-key decryption using the public key. See also crypto:public_decrypt/4
Public-key encryption using the private key.
Equivalent to encrypt_public(PlainText, Key, [])
.
Public-key encryption using the public key. See also crypto:public_encrypt/4
.
Types: Common
-type asn1_type() :: atom().
ASN.1 type present in the Public Key applications ASN.1 specifications.
-type der_encoded() :: binary().
ASN.1 DER encoded entity.
-type digest_type() :: crypto:sha2() | crypto:sha1() | md5 | none.
Hash function used to create a message digest
-type oid() :: tuple().
Object identifier, a tuple of integers as generated by the ASN.1
compiler.
Types: Keys
-type custom_key_opts() :: [term()].
Can be provided together with a custom private key, that specifies a key fun, to provide additional options understood by the fun.
-type dsa_private_key() :: #'DSAPrivateKey'{version :: term(), p :: term(), q :: term(), g :: term(), y :: term(), x :: term()}.
ASN.1 defined private key format for the DSA algorithm.
-type dsa_public_key() :: {dss_public_key(), #'Dss-Parms'{p :: term(), q :: term(), g :: term()}}.
ASN.1 defined public key format for the DSA algorithm.
-type dss_public_key() :: pos_integer().
ASN.1 defined public key format for the DSS algorithm (part of DSA key).
-type ecdsa_private_key() :: #'ECPrivateKey'{version :: term(), privateKey :: term(), parameters :: term(), publicKey :: term(), attributes :: term()}.
ASN.1 defined private key format for the ECDSA algorithm.
-type ecdsa_public_key() :: {#'ECPoint'{point :: term()}, {namedCurve, oid()} | #'ECParameters'{version :: term(), fieldID :: term(), curve :: term(), base :: term(), order :: term(), cofactor :: term()}}.
ASN.1 defined public key format for the ECDSA algorithm.
-type eddsa_private_key() :: #'ECPrivateKey'{parameters :: {namedCurve, oid()}, version :: term(), privateKey :: term(), publicKey :: term(), attributes :: term()}.
ASN.1 defined private key format for the EDDSA algorithm, possible oids: ?'id-Ed25519' | ?'id-Ed448'
ASN.1 defined public key format for the EDDSA algorithm, possible oids: ?'id-Ed25519' | ?'id-Ed448'
-type key_params() :: 'NULL' | #'RSASSA-PSS-params'{hashAlgorithm :: term(), maskGenAlgorithm :: term(), saltLength :: term(), trailerField :: term()} | {namedCurve, oid()} | #'ECParameters'{version :: term(), fieldID :: term(), curve :: term(), base :: term(), order :: term(), cofactor :: term()} | #'Dss-Parms'{p :: term(), q :: term(), g :: term()}.
ASN.1 defined parameters for public key algorithms.
-type private_key() :: rsa_private_key() | rsa_pss_private_key() | dsa_private_key() | ecdsa_private_key() | eddsa_private_key() | #{algorithm := eddsa | rsa_pss_pss | ecdsa | rsa | dsa, sign_fun => fun()}.
Supported private keys
-type public_key() :: rsa_public_key() | rsa_pss_public_key() | dsa_public_key() | ecdsa_public_key() | eddsa_public_key().
Supported public keys
-type rsa_private_key() :: #'RSAPrivateKey'{version :: term(), modulus :: term(), publicExponent :: term(), privateExponent :: term(), prime1 :: term(), prime2 :: term(), exponent1 :: term(), exponent2 :: term(), coefficient :: term(), otherPrimeInfos :: term()} | #{algorithm := rsa, encrypt_fun => fun()}.
ASN.1 defined private key format plain RSA algorithm or customization fun.
-type rsa_pss_private_key() :: {#'RSAPrivateKey'{version :: term(), modulus :: term(), publicExponent :: term(), privateExponent :: term(), prime1 :: term(), prime2 :: term(), exponent1 :: term(), exponent2 :: term(), coefficient :: term(), otherPrimeInfos :: term()}, #'RSASSA-PSS-params'{hashAlgorithm :: term(), maskGenAlgorithm :: term(), saltLength :: term(), trailerField :: term()}}.
ASN.1 defined private key format the RSSASSA-PSS algorithm or customization fun.
-type rsa_pss_public_key() :: {rsa_public_key(), #'RSASSA-PSS-params'{hashAlgorithm :: term(), maskGenAlgorithm :: term(), saltLength :: term(), trailerField :: term()}}.
ASN.1 defined public key format for the RSSASSA-PSS algorithm.
ASN.1 defined public key format for plain RSA algorithm.
Types: PEM files
-type pem_entry() :: {pki_asn1_type(), DerOrDerEncrypted :: binary(), not_encrypted | {Cipher :: iodata(), Salt :: binary() | {#'PBEParameter'{salt :: term(), iterationCount :: term()}, digest_type()} | #'PBES2-params'{keyDerivationFunc :: term(), encryptionScheme :: term()}}}.
Possible Ciphers
are "RC2-CBC" | "DES-CBC" | "DES-EDE3-CBC" Salt
could be generated with
crypto:strong_rand_bytes(8)
.
-type pki_asn1_type() ::
'Certificate' | 'RSAPrivateKey' | 'RSAPublicKey' | 'SubjectPublicKeyInfo' | 'DSAPrivateKey' |
'DHParameter' | 'PrivateKeyInfo' | 'CertificationRequest' | 'ContentInfo' |
'CertificateList' | 'ECPrivateKey' | 'OneAsymmetricKey' | 'EcpkParameters'.
ASN.1 type that can be found in PEM files that can be decode by the public_key application.
Types: Certificates
-type bad_cert_reason() :: cert_expired | invalid_issuer | invalid_signature | name_not_permitted | missing_basic_constraint | invalid_key_usage | duplicate_cert_in_path | {policy_requirement_not_met, term()} | {invalid_policy_mapping, term()} | {revoked, crl_reason()} | invalid_validity_dates | {revocation_status_undetermined, term()} | atom().
The reason that a certifcate gets rejected by the certificate path validation.
-type cert() :: der_encoded() | #'OTPCertificate'{tbsCertificate :: term(), signatureAlgorithm :: term(), signature :: term()}.
An encoded or decode certificate.
-type cert_id() :: {SerialNr :: integer(), issuer_name()}.
A certificate is identified by its serial-number and Issuer Name.
-type combined_cert() :: #cert{der :: public_key:der_encoded(), otp :: #'OTPCertificate'{tbsCertificate :: term(), signatureAlgorithm :: term(), signature :: term()}}.
A record that can be used to provide the certificate on both the DER encoded and the OTP decode format.
Such a construct can be useful to avoid conversions and problems that can arise due to relaxed decoding rules.
-type issuer_name() :: {rdnSequence, [[#'AttributeTypeAndValue'{type :: term(), value :: term()}]]}.
The value of the issuer part of a certificate.
-type policy_node() :: #{valid_policy := oid(), qualifier_set := [#'UserNotice'{noticeRef :: term(), explicitText :: term()} | {uri, string()}], expected_policy_set := [oid()]}.
Certificate policy information.
-type public_key_info() :: {oid(), rsa_public_key() | #'ECPoint'{point :: term()} | dss_public_key(), key_params()}.
Information a certificates public key.
Possible oids: ?'rsaEncryption' | ?'id-RSASSA-PSS' | ?'id-ecPublicKey' | ?'id-Ed25519' | ?'id-Ed448' | ?'id-dsa'
Types: Certificate Revocation
-type crl_reason() ::
unspecified | keyCompromise | cACompromise | affiliationChanged | superseded |
cessationOfOperation | certificateHold | privilegeWithdrawn | aACompromise.
The reason that a certifcate has been revoked as define by RFC 5280.
Types: Test Data
-type cert_opt() :: {digest, digest_type()} | {key, {namedCurve, oid()} | #'ECParameters'{version :: term(), fieldID :: term(), curve :: term(), base :: term(), order :: term(), cofactor :: term()} | {rsa, Size :: pos_integer(), Prime :: pos_integer()} | private_key()} | {validity, {From :: erlang:timestamp(), To :: erlang:timestamp()}} | {extensions, [#'Extension'{extnID :: term(), critical :: term(), extnValue :: term()}]}.
Options to customize generated test certificates
-type chain_opts() :: #{root := [cert_opt()], intermediates => [[cert_opt()]], peer := [cert_opt()]}.
Certificate customize options for diffrent parts of the certificate test chain.
-type conf_opt() :: {cert, der_encoded()} | {key, private_key()} | {cacerts, [der_encoded()]}.
Configuration options for the generated certificate test chain.
PEM API
Decodes PEM binary data and returns entries as ASN.1 DER encoded entities.
Example
{ok, PemBin} = file:read_file("cert.pem"). PemEntries = public_key:pem_decode(PemBin).
Creates a PEM binary.
Equivalent to pem_entry_decode(PemEntry, "")
.
-spec pem_entry_decode(PemEntry, Password) -> term() when PemEntry :: pem_entry(), Password :: iodata() | fun(() -> iodata()).
Decodes a PEM entry. pem_decode/1
returns a list of PEM
entries. Notice that if the PEM entry is of type 'SubjectPublickeyInfo', it is
further decoded to an rsa_public_key/0
or dsa_public_key/0
.
Password can be either an octet string or function which returns same type.
-spec pem_entry_encode(Asn1Type, Entity) -> pem_entry() when Asn1Type :: pki_asn1_type(), Entity :: term().
Equivalent to pem_entry_encode/3
.
-spec pem_entry_encode(Asn1Type, Entity, InfoPwd) -> pem_entry() when Asn1Type :: pki_asn1_type(), Entity :: term(), InfoPwd :: {CipherInfo, Password}, CipherInfo :: {Cipher :: iodata(), Salt :: binary() | {#'PBEParameter'{salt :: term(), iterationCount :: term()}, digest_type()} | #'PBES2-params'{keyDerivationFunc :: term(), encryptionScheme :: term()}}, Password :: iodata().
Creates a PEM entry that can be feed to pem_encode/1
.
If Asn1Type
is 'SubjectPublicKeyInfo'
, Entity
must be either an
rsa_public_key/0
, dsa_public_key/0
or an ecdsa_public_key/0
and this
function creates the appropriate 'SubjectPublicKeyInfo'
entry.
Key API
-spec compute_key(OthersECDHkey, MyECDHkey) -> SharedSecret when OthersECDHkey :: #'ECPoint'{point :: term()}, MyECDHkey :: #'ECPrivateKey'{version :: term(), privateKey :: term(), parameters :: term(), publicKey :: term(), attributes :: term()}, SharedSecret :: binary().
Computes shared secret.
-spec compute_key(OthersDHkey, MyDHkey, DHparms) -> SharedSecret when OthersDHkey :: crypto:dh_public(), MyDHkey :: crypto:dh_private(), DHparms :: #'DHParameter'{prime :: term(), base :: term(), privateValueLength :: term()}, SharedSecret :: binary().
Computes shared secret.
dh_gex_group(MinSize, SuggestedSize, MaxSize, Groups)
View Source (since OTP 18.2)-spec dh_gex_group(MinSize, SuggestedSize, MaxSize, Groups) -> {ok, {Size, Group}} | {error, term()} when MinSize :: pos_integer(), SuggestedSize :: pos_integer(), MaxSize :: pos_integer(), Groups :: undefined | [{Size, [Group]}], Size :: pos_integer(), Group :: {G, P}, G :: pos_integer(), P :: pos_integer().
Selects a group for Diffie-Hellman key exchange with the key size in the range
MinSize...MaxSize
and as close to SuggestedSize
as possible. If
Groups == undefined
a default set will be used, otherwise the group is
selected from Groups
.
First a size, as close as possible to SuggestedSize, is selected. Then one group
with that key size is randomly selected from the specified set of groups. If no
size within the limits of MinSize
and MaxSize
is available,
{error,no_group_found}
is returned.
The default set of groups is listed in lib/public_key/priv/moduli
. This file
may be regenerated like this:
$> cd $ERL_TOP/lib/public_key/priv/
$> generate
---- wait until all background jobs has finished. It may take several days !
$> cat moduli-* > moduli
$> cd ..; make
-spec generate_key(DHparams | ECparams | RSAparams) -> DHkeys | ECkey | RSAkey when DHparams :: #'DHParameter'{prime :: term(), base :: term(), privateValueLength :: term()}, DHkeys :: {PublicDH :: binary(), PrivateDH :: binary()}, ECparams :: {namedCurve, oid() | atom()} | #'ECParameters'{version :: term(), fieldID :: term(), curve :: term(), base :: term(), order :: term(), cofactor :: term()}, ECkey :: #'ECPrivateKey'{version :: term(), privateKey :: term(), parameters :: term(), publicKey :: term(), attributes :: term()}, RSAparams :: {rsa, Size, PubExp}, Size :: pos_integer(), PubExp :: pos_integer(), RSAkey :: #'RSAPrivateKey'{version :: term(), modulus :: term(), publicExponent :: term(), privateExponent :: term(), prime1 :: term(), prime2 :: term(), exponent1 :: term(), exponent2 :: term(), coefficient :: term(), otherPrimeInfos :: term()}.
Generates a new key pair. Note that except for Diffie-Hellman the public key is
included in the private key structure. See also crypto:generate_key/2
Sign/Verify API
-spec pkix_sign(Cert, Key) -> Der when Cert :: #'OTPTBSCertificate'{version :: term(), serialNumber :: term(), signature :: term(), issuer :: term(), validity :: term(), subject :: term(), subjectPublicKeyInfo :: term(), issuerUniqueID :: term(), subjectUniqueID :: term(), extensions :: term()}, Key :: private_key(), Der :: der_encoded().
Signs an 'OTPTBSCertificate'. Returns the corresponding DER-encoded certificate.
-spec pkix_verify(Cert, Key) -> boolean() when Cert :: der_encoded(), Key :: public_key().
Verifies PKIX x.509 certificate signature.
-spec sign(Msg, DigestType, Key) -> Signature when Msg :: binary() | {digest, binary()}, DigestType :: digest_type(), Key :: private_key(), Signature :: binary().
Equivalent to sign(Msg, DigestType, Key, [])
.
-spec sign(Msg, DigestType, Key, Options) -> Signature when Msg :: binary() | {digest, binary()}, DigestType :: digest_type(), Key :: private_key(), Options :: crypto:pk_sign_verify_opts() | custom_key_opts(), Signature :: binary().
Creates a digital signature.
The Msg
is either the binary "plain text" data to be signed or it is the
hashed value of "plain text", that is, the digest. The key, can besides a
standard key, be a map specifing a key algorithm and a fun that should handle
the signing. This may be used for customized signing with for instance hardware
security modules (HSM) or trusted platform modules (TPM).
-spec verify(Msg, DigestType, Signature, Key) -> boolean() when Msg :: binary() | {digest, binary()}, DigestType :: digest_type(), Signature :: binary(), Key :: public_key().
Equivalent to verify(Msg, DigestType, Signature, Key, [])
.
-spec verify(Msg, DigestType, Signature, Key, Options) -> boolean() when Msg :: binary() | {digest, binary()}, DigestType :: digest_type(), Signature :: binary(), Key :: public_key(), Options :: crypto:pk_sign_verify_opts().
Verifies a digital signature.
The Msg
is either the binary "plain text" data or it is the hashed value of
"plain text", that is, the digest.
Certificate API
-spec cacerts_clear() -> boolean().
Clears any loaded CA certificates, returns true if any was loaded.
-spec cacerts_get() -> [combined_cert()].
Returns the trusted CA certificates if any are loaded, otherwise uses
cacerts_load/0
to load them. The function fails if no cacerts
could be
loaded.
-spec cacerts_load() -> ok | {error, Reason :: term()}.
Loads the OS supplied trusted CA certificates.
-spec cacerts_load(File :: file:filename_all()) -> ok | {error, Reason :: term()}.
Loads the trusted CA certificates from a file.
-spec pkix_decode_cert(Cert, Type) -> #'Certificate'{tbsCertificate :: term(), signatureAlgorithm :: term(), signature :: term()} | #'OTPCertificate'{tbsCertificate :: term(), signatureAlgorithm :: term(), signature :: term()} when Cert :: der_encoded(), Type :: plain | otp.
Decodes an ASN.1 DER-encoded PKIX certificate.
Option otp
uses the customized ASN.1 specification OTP-PKIX.asn1 for
decoding and also recursively decode most of the standard parts.
-spec pkix_encode(Asn1Type, Entity, Type) -> Der when Asn1Type :: asn1_type(), Entity :: term(), Type :: otp | plain, Der :: der_encoded().
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 directly calls
der_encode/2
.
Note
Subtle ASN-1 encoding errors in certificates may be worked around when decoding, this may have the affect that the encoding a certificate back to DER may generate different bytes then the supplied original.
-spec pkix_hash_type(HashOid :: oid()) -> DigestType :: md5 | crypto:sha1() | crypto:sha2().
Translates OID to Erlang digest type
Checks if a certificate is a fixed Diffie-Hellman certificate.
-spec pkix_is_issuer(CertorCRL, IssuerCert) -> boolean() when CertorCRL :: cert() | #'CertificateList'{tbsCertList :: term(), signatureAlgorithm :: term(), signature :: term()}, IssuerCert :: cert().
Checks if IssuerCert
issued Cert
.
Checks if a certificate is self-signed.
-spec pkix_issuer_id(Cert, IssuedBy) -> {ok, ID :: cert_id()} | {error, Reason} when Cert :: cert(), IssuedBy :: self | other, Reason :: term().
Returns the x509 certificate issuer id, if it can be determined.
-spec pkix_normalize_name(Issuer) -> Normalized when Issuer :: issuer_name() | der_encoded(), Normalized :: issuer_name().
Normalizes an issuer name so that it can be easily compared to another issuer name.
-spec pkix_path_validation(Cert, CertChain, Options) -> {ok, {PublicKeyInfo, ConstrainedPolicyNodes}} | {error, {bad_cert, Reason :: bad_cert_reason()}} when Cert :: cert() | combined_cert() | atom(), CertChain :: [cert() | combined_cert()], Options :: [{max_path_length, integer()} | {verify_fun, {fun(), term()}}], PublicKeyInfo :: public_key_info(), ConstrainedPolicyNodes :: [policy_node()].
Performs a basic path validation according to RFC 5280.
However, CRL validation is done separately by pkix_crls_validate/3
and is to be called from the supplied
verify_fun
. The policy tree check was added in OTP-26.2 and if the
certificates include policies the constrained policy set with
potential qualifiers will be returned, these values are derived from
the policy tree created as part of the path validation algorithm. The
constrained set can be constrained only by the Certificate Authorities
or also by the user when the option policy_set
is provided to this
function. The qualifiers convey information about the valid policy and
is intended as information to end users.
Available options:
{verify_fun, {fun(), UserState::term()} - The fun must be defined as:
fun(OtpCert :: #'OTPCertificate'{}, Event :: {bad_cert, Reason :: atom() | {revoked, atom()}} | {extension, #'Extension'{}}, UserState :: term()) -> {valid, UserState :: term()} | {valid_peer, UserState :: term()} | {fail, Reason :: term()} | {unknown, UserState :: term()}.
or as:
fun(OtpCert :: #'OTPCertificate'{}, DerCert :: der_encoded(), Event :: {bad_cert, Reason :: atom() | {revoked, atom()}} | {extension, #'Extension'{}}, UserState :: term()) -> {valid, UserState :: term()} | {valid_peer, UserState :: term()} | {fail, Reason :: term()} | {unknown, UserState :: term()}.
The verify callback can have 3 or 4 arguments in case the DER encoded version is needed by the callback.
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 asselfsigned_peer
, as well as verifying application-specific extensions. If called with an extension unknown to the user application, the return value{unknown, UserState}
is to be used.Note
If you need the DER encoded version of the certificate and have the OTP decoded version encoding it back can fail to give the correct result, due to work arounds for common misbehaving encoders. So it is recommended to call
pkix_path_validation
withCert
andCertChain
arguments asder_encoded() | #cert{}
and[der_encoded() | #cert{}]
. Also note that the path validation itself needs both the encoded and the decoded version of the certificate.Warning
Note that user defined custom
verify_fun
may alter original path validation error (e.gselfsigned_peer
). Use with caution.{max_path_length, integer()} - The
max_path_length
is the maximum number of non-self-issued intermediate certificates that can follow the peer certificate in a valid certification path. So, ifmax_path_length
is 0, the PEER must be signed by the trusted ROOT-CA directly, if it is 1, the path can be PEER, CA, ROOT-CA, if it is 2, the path can be PEER, CA, CA, ROOT-CA, and so on.{policy_set, [oid()]}(Since OTP 26.2)
The set of policies that will be accepted, defaults to the special value[?anyPolicy]
that will accept all policies.{explicit_policy, boolean()}(Since OTP 26.2)
Explicitly require that each certificate in the path must include at least one of the certificate policies in thepolicy_set
.{inhibit_policy_mapping, boolean()}(Since OTP 26.2)
Prevent policies to be mapped to other policies.{inhibit_any_policy, boolean()}(Since OTP 26.2)
Prevent the special policy?anyPolicy
from being accepted.
Explanations of reasons for a bad certificate:
cert_expired - Certificate is no longer valid as its expiration date has passed.
invalid_issuer - Certificate issuer name does not match the name of the issuer certificate in the chain.
invalid_signature - Certificate was not signed by its issuer certificate in the chain.
name_not_permitted - Invalid Subject Alternative Name extension.
missing_basic_constraint - Certificate, required to have the basic constraints extension, does not have a basic constraints extension.
invalid_key_usage - Certificate key is used in an invalid way according to the key-usage extension.
{revoked, crl_reason()} - Certificate has been revoked.
invalid_validity_dates - The validity section of the X.509 certificate(s) contains invalid date formats not matching the RFC.
atom() - Application-specific error reason that is to be checked by the
verify_fun
.
-spec pkix_sign_types(AlgorithmId) -> {DigestType, SignatureType} when AlgorithmId :: oid(), DigestType :: digest_type(), SignatureType :: rsa | dsa | ecdsa | eddsa.
Translates signature algorithm OID to Erlang digest and signature types.
The AlgorithmId
is the signature OID from a certificate or a certificate
revocation list.
Returns the X509 certificate subject id.
-spec pkix_verify_hostname(Cert, ReferenceIDs) -> boolean() when Cert :: cert(), ReferenceIDs :: [{uri_id | dns_id | ip | srv_id | atom() | oid(), string()} | {ip, inet:ip_address() | string()}].
Equivalent to pkix_verify_hostname(Cert, ReferenceIDs, [])
.
pkix_verify_hostname(Cert, ReferenceIDs, Options)
View Source (since OTP 19.3)-spec pkix_verify_hostname(Cert, ReferenceIDs, Options) -> boolean() when Cert :: cert(), ReferenceIDs :: [{uri_id | dns_id | ip | srv_id | atom() | oid(), string()} | {ip, inet:ip_address() | string()}], Options :: [{match_fun | fail_callback | fqdn_fun, fun()}].
This function checks that the Presented Identifier (e.g hostname) in a peer certificate is in agreement with at least one of the Reference Identifier that the client expects to be connected to.
The function is intended to be added as an extra client check of the peer certificate when performing public_key:pkix_path_validation/3
See RFC 6125 for detailed information about hostname verification. The User's Guide and code examples describes this function more detailed.
The option funs are described here:
match_fun
fun(ReferenceId::ReferenceId() | FQDN::string(), PresentedId::{dNSName,string()} | {uniformResourceIdentifier,string() | {iPAddress,list(byte())} | {OtherId::atom()|oid(),term()}})
This function replaces the default host name matching rules. The fun should return a boolean to tell if the Reference ID and Presented ID matches or not. The match fun can also return a third value, value, the atom
default
, if the default matching rules shall apply. This makes it possible to augment the tests with a special case:fun(....) -> true; % My special case (_, _) -> default % all others falls back to the inherit tests end
See
pkix_verify_hostname_match_fun/1
for a function that takes a protocol name as argument and returns afun/2
suitable for this option and Re-defining the match operation in the User's Guide for an example.Note
Reference Id values given as binaries will be converted to strings, and ip references may be given in string format that is "10.0.1.1" or "1234::5678:9012" as well as on the format
inet:ip_address/0
fail_callback
- If a matching fails, there could be circumstances when the certificate should be accepted anyway. Think for example of a web browser where you choose to accept an outdated certificate. This option enables implementation of such an exception but for hostnames. Thisfun/1
is called when noReferenceID
matches. The return value of the fun (aboolean/0
) decides the outcome. Iftrue
the the certificate is accepted otherwise it is rejected. See "Pinning" a Certificate in the User's Guide.fqdn_fun
- This option augments the host name extraction from URIs and other Reference IDs. It could for example be a very special URI that is not standardised. The fun takes a Reference ID as argument and returns one of:- the hostname
- the atom
default
: the default host name extract function will be used - the atom
undefined
: a host name could not be extracted. The pkix_verify_hostname/3 will returnfalse
.
For an example, see Hostname extraction in the User's Guide.
-spec pkix_verify_hostname_match_fun(Protocol) -> Result when Protocol :: https, Result :: fun().
The return value of calling this function is intended to be used in the
match_fun
option in pkix_verify_hostname/3
.
The returned fun augments the verify hostname matching according to the specific rules for the protocol in the argument.
Note
Currently supported https fun will allow wildcard certificate matching as specified by the HTTP standard. Note that for instance LDAP have a different set of wildcard matching rules. If you do not want to allow wildcard certificates (recommended from a security perspective) or otherwise customize the hostname match the default match function used by ssl application will be sufficient.
Certificate Revocation API
-spec pkix_crl_issuer(CRL) -> Issuer when CRL :: der_encoded() | #'CertificateList'{tbsCertList :: term(), signatureAlgorithm :: term(), signature :: term()}, Issuer :: issuer_name().
Returns the issuer of the CRL
.
-spec pkix_crl_verify(CRL, Cert) -> boolean() when CRL :: der_encoded() | #'CertificateList'{tbsCertList :: term(), signatureAlgorithm :: term(), signature :: term()}, Cert :: cert().
Verify that Cert
is the CRL
signer.
pkix_crls_validate(OTPcertificate, DPandCRLs, Options)
View Source (since OTP R16B)-spec pkix_crls_validate(OTPcertificate, DPandCRLs, Options) -> CRLstatus when OTPcertificate :: #'OTPCertificate'{tbsCertificate :: term(), signatureAlgorithm :: term(), signature :: term()}, DPandCRLs :: [DPandCRL], DPandCRL :: {DP, {DerCRL, CRL}}, DP :: #'DistributionPoint'{distributionPoint :: term(), reasons :: term(), cRLIssuer :: term()}, DerCRL :: der_encoded(), CRL :: #'CertificateList'{tbsCertList :: term(), signatureAlgorithm :: term(), signature :: term()}, Options :: [{atom(), term()}], CRLstatus :: valid | {bad_cert, BadCertReason}, BadCertReason :: revocation_status_undetermined | {revocation_status_undetermined, Reason :: term()} | {revoked, crl_reason()}.
Performs CRL validation. It is intended to be called from the verify fun of pkix_path_validation/3 .
Available options:
{update_crl, fun()} - The fun has the following type specification:
fun(#'DistributionPoint'{}, #'CertificateList'{}) -> #'CertificateList'{}
The fun uses the information in the distribution point to access the latest possible version of the CRL. If this fun is not specified, Public Key uses the default implementation:
fun(_DP, CRL) -> CRL end
{issuer_fun, {fun(), UserState::term()}} - The fun has the following type specification:
fun(#'DistributionPoint'{}, #'CertificateList'{}, {rdnSequence,[#'AttributeTypeAndValue'{}]}, UserState::term()) -> {ok, #'OTPCertificate'{}, [der_encoded]}
The fun returns the root certificate and certificate chain that has signed the CRL.
fun(DP, CRL, Issuer, UserState) -> {ok, RootCert, CertChain}
{undetermined_details, boolean()} - Defaults to false. When revocation status cannot be determined, and this option is set to true, details of why no CRLs where accepted are included in the return value.
-spec pkix_dist_point(Cert) -> DistPoint when Cert :: cert(), DistPoint :: #'DistributionPoint'{distributionPoint :: term(), reasons :: term(), cRLIssuer :: term()}.
Creates a distribution point for CRLs issued by the same issuer as Cert
. Can
be used as input to pkix_crls_validate/3
-spec pkix_dist_points(Cert) -> DistPoints when Cert :: cert(), DistPoints :: [#'DistributionPoint'{distributionPoint :: term(), reasons :: term(), cRLIssuer :: term()}].
Extracts distribution points from the certificates extensions.
-spec pkix_match_dist_point(CRL, DistPoint) -> boolean() when CRL :: der_encoded() | #'CertificateList'{tbsCertList :: term(), signatureAlgorithm :: term(), signature :: term()}, DistPoint :: #'DistributionPoint'{distributionPoint :: term(), reasons :: term(), cRLIssuer :: term()}.
Checks whether the given distribution point matches the Issuing Distribution Point of the CRL, as described in RFC 5280.
If the CRL doesn't have an Issuing Distribution Point extension, the distribution point always matches.
pkix_ocsp_validate(Cert, IssuerCert, OcspRespDer, NonceExt, Options)
View Source (since OTP 27.0)-spec pkix_ocsp_validate(Cert, IssuerCert, OcspRespDer, NonceExt, Options) -> {ok, Details} | {error, {bad_cert, Reason}} when Cert :: cert(), IssuerCert :: cert(), OcspRespDer :: der_encoded(), NonceExt :: undefined | binary(), Options :: [{is_trusted_responder_fun, fun((combined_cert()) -> boolean)}], Details :: list(), Reason :: bad_cert_reason().
Perform OCSP response validation according to RFC 6960. Returns {'ok', Details} when OCSP response is successfully validated and {error, {bad_cert, Reason}} otherwise.
Available options:
{is_trusted_responder_fun, fun()} - The fun has the following type specification:
fun(#cert{}) -> boolean()
The fun returns the
true
if certificate in the argument is trusted. If this fun is not specified, Public Key uses the default implementation:fun(_) -> false end
Note
OCSP response can be provided without a nonce value - even if it was requested by the client. In such cases {missing, ocsp_nonce} will be returned in Details list.
-spec short_name_hash(Name) -> string() when Name :: issuer_name().
Generates a short hash of an issuer name. The hash is returned as a string containing eight hexadecimal digits.
The return value of this function is the same as the result of the commands
openssl crl -hash
and openssl x509 -issuer_hash
, when passed the issuer name
of a CRL or a certificate, respectively. This hash is used by the c_rehash
tool to maintain a directory of symlinks to CRL files, in order to facilitate
looking up a CRL by its issuer name.
ASN.1 Encoding API
-spec der_decode(Asn1Type, Der) -> Entity when Asn1Type :: asn1_type(), Der :: der_encoded(), Entity :: term().
Decodes a public-key ASN.1 DER encoded entity.
-spec der_encode(Asn1Type, Entity) -> Der when Asn1Type :: asn1_type(), Entity :: term(), Der :: binary().
Encodes a public-key entity with ASN.1 DER encoding.
Test Data API
-spec pkix_test_data(ChainConf) -> TestConf when ChainConf :: #{server_chain := chain_opts(), client_chain := chain_opts()} | chain_opts(), TestConf :: #{server_config := [conf_opt()], client_config := [conf_opt()]} | [conf_opt()].
Creates certificate configuration(s) consisting of certificate and its private key plus CA certificate bundle, for a client and a server, intended to facilitate automated testing of applications using X509-certificates, often through SSL/TLS. The test data can be used when you have control over both the client and the server in a test scenario.
When this function is called with a map containing client and server chain
specifications; it generates both a client and a server certificate chain where
the cacerts
returned for the server contains the root cert the server should
trust and the intermediate certificates the server should present to connecting
clients. The root cert the server should trust is the one used as root of the
client certificate chain. Vice versa applies to the cacerts
returned for the
client. The root cert(s) can either be pre-generated with
pkix_test_root_cert/2 , or if options are specified;
it is (they are) generated.
When this function is called with a list of certificate options; it generates a
configuration with just one node certificate where cacerts
contains the root
cert and the intermediate certs that should be presented to a peer. In this case
the same root cert must be used for all peers. This is useful in for example an
Erlang distributed cluster where any node, towards another node, acts either as
a server or as a client depending on who connects to whom. The generated
certificate contains a subject altname, which is not needed in a client
certificate, but makes the certificate useful for both roles.
Explanation of the options used to customize certificates in the generated chains:
{digest, digest_type()} - Hash algorithm to be used for signing the certificate together with the key option. Defaults to sha that is sha1.
{key, ec_params()| {rsa, Size:pos_integer(), Prime::pos_integer()} | private_key()} - Parameters to be used to call public_key:generate_key/1, to generate a key, or an existing key. Defaults to generating an ECDSA key. Note this could fail if Erlang/OTP is compiled with a very old cryptolib.
{validity, {From::erlang:timestamp(), To::erlang:timestamp()}} - The validity period of the certificate.
{extensions, [#'Extension'{}]} - Extensions to include in the certificate.
Default extensions included in CA certificates if not otherwise specified are:
[#'Extension'{extnID = ?'id-ce-keyUsage', extnValue = [keyCertSign, cRLSign], critical = false}, #'Extension'{extnID = ?'id-ce-basicConstraints', extnValue = #'BasicConstraints'{cA = true}, critical = true}]
Default extensions included in the server peer cert if not otherwise specified are:
[#'Extension'{extnID = ?'id-ce-keyUsage', extnValue = [digitalSignature, keyAgreement], critical = false}, #'Extension'{extnID = ?'id-ce-subjectAltName', extnValue = [{dNSName, Hostname}], critical = false}]
Hostname is the result of calling net_adm:localhost() in the Erlang node where this function is called.
Note
Note that the generated certificates and keys does not provide a formally correct PKIX-trust-chain and they cannot be used to achieve real security. This function is provided for testing purposes only.
-spec pkix_test_root_cert(Name, Options) -> RootCertAndKey when Name :: string(), Options :: [cert_opt()], RootCertAndKey :: #{cert := der_encoded(), key := private_key()}.
Generates a root certificate that can be used in multiple calls to
pkix_test_data/1
when you want the same root certificate for several generated
certificates.
Legacy RSA Encryption API
-spec decrypt_private(CipherText, Key) -> PlainText when CipherText :: binary(), Key :: rsa_private_key(), PlainText :: binary().
Equivalent to decrypt_private(CipherText, Key, [])
.
-spec decrypt_private(CipherText, Key, Options) -> PlainText when CipherText :: binary(), Key :: rsa_private_key(), Options :: crypto:pk_encrypt_decrypt_opts(), PlainText :: binary().
Public-key decryption using the private key. See also crypto:private_decrypt/4
Warning
This is a legacy function, for security reasons do not use with rsa_pkcs1_padding.
-spec decrypt_public(CipherText, Key) -> PlainText when CipherText :: binary(), Key :: rsa_public_key(), PlainText :: binary().
Equivalent to decrypt_public(CipherText, Key, [])
.
-spec decrypt_public(CipherText, Key, Options) -> PlainText when CipherText :: binary(), Key :: rsa_public_key(), Options :: crypto:pk_encrypt_decrypt_opts(), PlainText :: binary().
Public-key decryption using the public key. See also crypto:public_decrypt/4
Warning
This is a legacy function, for security reasons do not use with rsa_pkcs1_padding. For digital signatures the use of
verify/4
together withsign/3
is a prefered solution.
-spec encrypt_private(PlainText, Key) -> CipherText when PlainText :: binary(), Key :: rsa_private_key(), CipherText :: binary().
Equivalent to encrypt_private(PlainText, Key, [])
.
-spec encrypt_private(PlainText, Key, Options) -> CipherText when PlainText :: binary(), Key :: rsa_private_key(), Options :: crypto:pk_encrypt_decrypt_opts() | custom_key_opts(), CipherText :: binary().
Public-key encryption using the private key.
See also crypto:private_encrypt/4
. The key, can besides a standard
RSA key, be a map specifing the key algorithm rsa
and a fun to
handle the encryption operation. This may be used for customized the
encryption operation with for instance hardware security modules (HSM)
or trusted platform modules (TPM).
Warning
This is a legacy function, for security reasons do not use with rsa_pkcs1_padding. For digital signatures use of
sign/3
together withverify/4
is the prefered solution.
-spec encrypt_public(PlainText, Key) -> CipherText when PlainText :: binary(), Key :: rsa_public_key(), CipherText :: binary().
Equivalent to encrypt_public(PlainText, Key, [])
.
-spec encrypt_public(PlainText, Key, Options) -> CipherText when PlainText :: binary(), Key :: rsa_public_key(), Options :: crypto:pk_encrypt_decrypt_opts(), CipherText :: binary().
Public-key encryption using the public key. See also crypto:public_encrypt/4
.
Warning
This is a legacy function, for security reasons do not use with rsa_pkcs1_padding.