CkCert

The authority key identifier of the certificate in base64 string format. This is only present if the certificate contains the extension OID 2.5.29.35.

Applies only when running on a Microsoft Windows operating system. If true, then any method that returns a certificate will not try to also access the associated private key, assuming one exists. This is useful if the certificate was installed with high-security such that a private key access would trigger the Windows OS to display a security warning dialog. The default value of this property is false.

The version of the certificate (1, 2, or 3). A value of 0 indicates an error -- the most likely cause being that the certificate object is empty (i.e. was never loaded with a certificate). Note: This is not the version of the software, it is the version of the X.509 certificate object. The version of the Chilkat certificate software is indicated by the Version property.

(Relevant only when running on a Microsoft Windows operating system.) If the HasKeyContainer property is true, then the certificate is linked to a key container and this property contains the name of the associated CSP (cryptographic service provider). When a certificate is linked to a key container , the following properties will provide information about the key container and private key: CspName, KeyContainerName, MachineKeyset, and Silent.

If set to a file path, causes each Chilkat method or property call to automatically append it's LastErrorText to the specified log file. The information is appended such that if a hang or crash occurs, it is possible to see the context in which the problem occurred, as well as a history of all Chilkat calls up to the point of the problem. The VerboseLogging property can be set to provide more detailed information.

This property is typically used for debugging the rare cases where a Chilkat method call hangs or generates an exception that halts program execution (i.e. crashes). A hang or crash should generally never happen. The typical causes of a hang are:

1. a timeout related property was set to 0 to explicitly indicate that an infinite timeout is desired,
2. the hang is actually a hang within an event callback (i.e. it is a hang within the application code), or
3. there is an internal problem (bug) in the Chilkat code that causes the hang.

Has a value of true if the certificate or any certificate in the chain of authority has expired. (This information is not available when running on Windows 95/98 computers.)

Returns a string containing a comma separated list of keywords with the extended key usages of the certificate. The list of possible extended key usages are:

• serverAuth - TLS WWW server authentication
• clientAuth - TLS WWW client authentication
• codeSigning - Signing of downloadable executable code
• emailProtection - Email protection
• timeStamping - Binding the hash of an object to a time
• OCSPSigning - Signing OCSP responses

true if this certificate can be used for client authentication, otherwise false.

true if this certificate can be used for code signing, otherwise false.

true if this certificate can be used for sending secure email, otherwise false.

true if this certificate can be used for server authentication, otherwise false.

true if this certificate can be used for time stamping, otherwise false.

(Relevant only when running on a Microsoft Windows operating system.) Indicates whether this certificate is linked to a key container. If true then the certificate is linked to a key container (usually containing a private key). If false, then it is not.

When a certificate is linked to a key container , the following properties will provide information about the key container and private key: CspName, KeyContainerName, MachineKeyset, and Silent.

Bitflags indicating the intended usages of the certificate. The flags are:
Digital Signature: 0x80
Non-Repudiation: 0x40
Key Encipherment: 0x20
Data Encipherment: 0x10
Key Agreement: 0x08
Certificate Signing: 0x04
CRL Signing: 0x02
Encipher-Only: 0x01

true if this is the root certificate, otherwise false.

The certificate issuer's country.

The certificate issuer's common name.

The issuer's full distinguished name.

The certificate issuer's email address.

The certificate issuer's locality, which could be a city, count, township, or other geographic region.

The certificate issuer's organization, which is typically the company name.

The certificate issuer's organizational unit, which is the unit within the organization.

The certificate issuer's state or province.

(Relevant only when running on a Microsoft Windows operating system.) If the HasKeyContainer property is true, then the certificate is linked to a key container and this property contains the name of the key container.

When a certificate is linked to a key container , the following properties will provide information about the key container and private key: CspName, KeyContainerName, MachineKeyset, and Silent.

Provides information in HTML format about the last method/property called. If a method call returns a value indicating failure, or behaves unexpectedly, examine this property to get more information.

Provides information in plain-text format about the last method/property called. If a method call returns a value indicating failure, or behaves unexpectedly, examine this property to get more information.

Provides information in XML format about the last method/property called. If a method call returns a value indicating failure, or behaves unexpectedly, examine this property to get more information.

Indicate whether the last method call succeeded or failed. A value of true indicates success, a value of false indicates failure. This property is automatically set for method calls. It is not modified by property accesses. The property is automatically set to indicate success for the following types of method calls:

• Any method that returns a string.
• Any method returning a Chilkat object, binary bytes, or a date/time.
• Any method returning a standard boolean status value where success = true and failure = false.
• Any method returning an integer where failure is defined by a return value less than zero.

Note: Methods that do not fit the above requirements will always set this property equal to true. For example, a method that returns no value (such as a "void" in C++) will technically always succeed.

(Relevant only when running on a Microsoft Windows operating system.) If the HasKeyContainer property is true, then the certificate is linked to a key container and this property indicates whether the key container is in the machine's keyset or in the keyset specific to the logged on user's account. If true, the key container is within the machine keyset. If false, it's in the user's keyset.

When a certificate is linked to a key container , the following properties will provide information about the key container and private key: CspName, KeyContainerName, MachineKeyset, and Silent.

If present in the certificate's extensions, returns the OCSP URL of the certificate. (The Online Certificate Status Protocol (OCSP) is an Internet protocol used for obtaining the revocation status of an X.509 digital certificate.)

(Relevant only when running on a Microsoft Windows operating system.) Indicates whether the private key was installed with security settings that allow it to be re-exported.

true if the certificate or any certificate in the chain of authority has been revoked. This information is not available when running on Windows 95/98 computers. Note: If this property is false, it could mean that it was not able to check the revocation status. Because of this uncertainty, a CheckRevoked method has been added. It returns an integer indicating one of three possible states: 1 (revoked) , 0 (not revoked), -1 (unable to check revocation status).

The RFC822 name of the certificate. (The RFC822 name is one part of the Subject Alternative Name extension of a certificate, if it exists. It is often the only part of the SAN.)

If the certificate contains a list of RFC822 names then this property will return the comma separated list of names.

Starting in Chilkat v9.5.0.85, to get the complete Subject Alternative Name extension as XML, use the SubjectAlternativeName property.

true if this is a self-signed certificate, otherwise false.

The certificate's serial number as a decimal string.

The certificate's serial number as a hexidecimal string.

Hexidecimal string of the SHA-1 thumbprint for the certificate. (This is the SHA1 hash of the binary DER representation of the entire X.509 certificate.)

Returns true if the certificate and all certificates in the chain of authority have valid signatures, otherwise returns false.

(Relevant only when running on a Microsoft Windows operating system.)

If the HasKeyContainer property is true, then the certificate is linked to a key container and this property indicates that the key container will attempt to open any keys silently without any user interface prompts.

When a certificate is linked to a key container , the following properties will provide information about the key container and private key: CspName, KeyContainerName, MachineKeyset, and Silent.

If set to true, then no dialog will automatically popup if the SmartCardPin is incorrect. Instead, the method requiring the private key on the smart card will fail. The default value of this property is false, which means that if the SmartCardPin property is incorrect, a dialog with prompt will be displayed.

Can be set to the PIN value for a certificate / private key stored on a smart card.

The subject alternative name (SAN) name of the certificate returned as XML. See the examples linked below.

The certificate subject's country.

The certificate subject's common name.

The certificate subject's full distinguished name.

The certificate subject's email address.

The subject key identifier of the certificate in base64 string format. This is only present if the certificate contains the extension OID 2.5.29.14.

The certificate subject's locality, which could be a city, count, township, or other geographic region.

The certificate subject's organization, which is typically the company name.

The certificate subject's organizational unit, which is the unit within the organization.

The certificate subject's state or province.

Returns true if the certificate has a trusted root authority, otherwise returns false.

Note: As of version 9.5.0.41, the notion of what your application deems as trusted becomes more specific. The TrustedRoots class/object was added in v9.5.0.0. Prior to this, a certificate was considered to be anchored by a trusted root if the certificate chain could be established to a root (self-signed) certificate, AND if the root certificate was located somewhere in the Windows registry-based certificate stores. There are two problems with this: (1) it's a Windows-only solution. This property would always return false on non-Windows systems, and (2) it might be considered not a strong enough set of conditions for trusting a root certificate.

As of version 9.5.0.41, this property pays attention to the new TrustedRoots class/object, which allows for an application to specificallly indicate which root certificates are to be trusted. Certificates may be added to the TrustedRoots object via the LoadCaCertsPem or AddCert methods, and then activated by calling the TrustedRoots.Activate method. The activated trusted roots are deemed to be trusted in any Chilkat API method/property that needs to make this determination. In addition, the TrustedRoots object has a property named TrustSystemCaRoots, which defaults to true, which allows for backward compatibility. It will trust CA certificates stored in the Windows registry-based certificate stores, or if on Linux, will trust certificates found in /etc/ssl/certs/ca-certificates.crt.

This is a catch-all property to be used for uncommon needs. This property defaults to the empty string, and should typically remain empty.

When set to true, all "const char *" arguments are interpreted as utf-8 strings. If set to false (the default), then "const char *" arguments are interpreted as ANSI strings. Also, when set to true, and Chilkat method returning a "const char *" is returning the utf-8 representation. If set to false, all "const char *" return values are ANSI strings.

The date (in RFC822 string format) that this certificate becomes (or became) valid. It is a GMT/UTC date that is returned.

The date (in RFC822 string format) that this certificate becomes (or became) invalid. It is a GMT/UTC date that is returned.

If set to true, then the contents of LastErrorText (or LastErrorXml, or LastErrorHtml) may contain more verbose information. The default value is false. Verbose logging should only be used for debugging. The potentially large quantity of logged information may adversely affect peformance.

Version of the component/library, such as "9.5.0.94"

Returns 1 if the certificate has been revoked, 0 if not revoked, and -1 if unable to check the revocation status.

Note: This method is only implemented on Windows systems. It uses the underlying Microsoft CertVerifyRevocation Platform SDK function to check the revocation status of a certificate. (Search "CertVerifyRevocation" to get information about it.)

Non-Windows (and Windows) applications can send an OCSP request as shown in the example below.

Verifies that the SmartCardPin property setting is correct. Returns 1 if correct, 0 if incorrect, and -1 if unable to check because the underlying CSP does not support the functionality.

Exports the digital certificate to ASN.1 DER format.

Returns true for success, false for failure.

Exports the digital certificate in ASN.1 DER format to a BinData object.

Returns true for success, false for failure.

Exports the digital certificate to ASN.1 DER format binary file.

Returns true for success, false for failure.

Exports the digital certificate to an unencrypted PEM formatted string.

Returns true for success, false for failure.

Exports the digital certificate to an unencrypted PEM formatted file.

Returns true for success, false for failure.

Exports a certificate to an XML format where the XML tags are the names of the ASN.1 objects that compose the X.509 certificate. Binary data is either hex or base64 encoded. (The binary data for a "bits" ASN.1 tag is hex encoded, whereas for all other ASN.1 tags, such as "octets", it is base64.)

Returns true for success, false for failure.

Exports the certificate's private key.

Returns nil on failure

Exports the certificate's public key.

Returns nil on failure

Exports the certificate and private key (if available) to pfxData. The password is what will be required to access the PFX contents at a later time. If includeCertChain is true, then the certificates in the chain of authority are also included in the PFX.

Returns true for success, false for failure.

Exports the certificate and private key (if available) to an in-memory PFX image. The password is what will be required to access the PFX contents at a later time. If includeCertChain is true, then the certificates in the chain of authority are also included in the PFX.

Returns true for success, false for failure.

Exports the certificate and private key (if available) to a PFX (.pfx or .p12) file. The output PFX is secured using the pfxPassword. If bIncludeCertChain is true, then the certificates in the chain of authority are also included in the PFX output file.

Returns true for success, false for failure.

Finds and returns the issuer certificate. If the certificate is a root or self-issued, then the certificate returned is a copy of the caller certificate. (The IsRoot property can be check to see if the certificate is a root (or self-issued) certificate.)

Returns nil on failure

Returns a certficate chain object containing all the certificates (including this one), in the chain of authentication to the trusted root (if possible). If this certificate object was loaded from a PFX, then the certiicates contained in the PFX are automatically available for building the certificate chain. The UseCertVault method can be called to provide additional certificates that might be required to build the cert chain. Finally, the TrustedRoots object can be used to provide a way of making trusted root certificates available.

Note: Prior to v9.5.0.50, this method would fail if the certificate chain could not be completed to the root. Starting in v9.5.0.50, the incomplete certificate chain will be returned. The certificate chain's ReachesRoot property can be examined to see if the chain was completed to the root.

On Windows systems, the registry-based certificate stores are automatically consulted if needed to locate intermediate or root certificates in the chain. Chilkat searches certificate stores in the following order. See System Store Locations for more information.

1. Current-User "CA" Certificate Store
2. Local-Machine "CA" Certificate Store
3. Current-User "Root" Certificate Store
4. Local-Machine "Root" Certificate Store
5. Current-User "MY" Certificate Store
6. Local-Machine "MY" Certificate Store
7. Current-User "ADDRESSBOOK" Certificate Store (if it exists)
8. Local-Machine "ADDRESSBOOK" Certificate Store (if it exists)

Returns nil on failure

Returns a base64 encoded string representation of the certificate's binary DER format, which can be passed to SetFromEncoded to recreate the certificate object.

Returns true for success, false for failure.

Returns the certificate extension data as a string. This method should only be called for those extensions with text values NOT stored as binary ASN.1. In most cases, applications should call GetExtensionAsXml because most extensions contain ASN.1 values that need to be decoded..

Returns true for success, false for failure.

Returns the certificate extension data in XML format (converted from ASN.1). The oid is an OID, such as the ones listed here: http://www.alvestrand.no/objectid/2.5.29.html

Note: In many cases, the data within the XML is returned base64 encoded. An application may need to take one further step to base64 decode the information contained within the XML.

Returns true for success, false for failure.

Returns the certificate extension data specified by oid in bd.

Returns true for success, false for failure.

Exports the certificate's private key to a PEM string (if the private key is available).

Returns true for success, false for failure.

Loads the bd with the certificate's public key in ASN.1 DER format. If the key type (such as RSA) supports both PKCS1 and PKCS8 formats, then preferPkcs1 selects which format to return.

Returns true for success, false for failure.

Loads the bd with the certificate's signature.

Returns true for success, false for failure.

Returns the SPKI Fingerprint suitable for use in pinning. (See RFC 7469.) An SPKI Fingerprint is defined as the output of a known cryptographic hash algorithm whose input is the DER-encoded ASN.1 representation of the Subject Public Key Info (SPKI) of an X.509 certificate. The hashAlg specifies the hash algorithm and may be "sha256", "sha384", "sha512", "sha1", "md2", "md5", "haval", "ripemd128", "ripemd160","ripemd256", or "ripemd320". The encoding specifies the encoding, and may be "base64", "hex", or any of the encoding modes specified in the article at the link below.

Returns true for success, false for failure.

Returns a part of the certificate's subject by name or OID. The partNameOrOid can be a part name, such as "CN", "O", "OU", "E", "S", "L", "C", or "SERIALNUMBER", or it can be an OID such as "2.5.4.3".

Returns true for success, false for failure.

Returns the date/time this certificate becomes (or became) valid.

Returns nil on failure

Returns the date/time this certificate becomes (or became) invalid.

Returns nil on failure

Returns an encoded hash of a particular part of the certificate. The part may be one of the following:

• IssuerDN
• IssuerPublicKey
• SubjectDN
• SubjectPublicKey

The hashAlg is the name of the hash algorithm, such as "sha1", "sha256", "sha384", "sha512", "md5", etc. The encoding is the format to return, such as "hex", "base64", etc.

Returns true for success, false for failure.

Returns true if a private key associated with the certificate is available.

Links to the certificate's private key located on an HSM (smart card, token, or cloud HSM). Once linked, the certificate can be used for signing where the signing occurs on the HSM. See the example below for more detailed information.

Returns true for success, false for failure.

(Relevant only when running on a Microsoft Windows operating system.) Searches the Windows Local Machine and Current User registry-based certificate stores for a certificate having the common name specified. If found, the certificate is loaded and ready for use.

Returns true for success, false for failure.

(Relevant only when running on a Microsoft Windows operating system.) Searches the Windows Local Machine and Current User registry-based certificate stores for a certificate containing the email address specified. If found, the certificate is loaded and ready for use.

Returns true for success, false for failure.

(Relevant only when running on a Microsoft Windows operating system.) Searches the Windows Local Machine and Current User registry-based certificate stores for a certificate matching the issuerCN and having an issuer matching the serialNumber. If found, the certificate is loaded and ready for use.

Note: The hex serial number should be uppercase. Starting in Chilkat v9.5.0.88, the hex serial number is case-insensitive.

Returns true for success, false for failure.

(Relevant only when running on a Microsoft Windows operating system.) Searches the Windows Local Machine and Current User registry-based certificate stores for a certificate containing a subject part matching the oid and value.

Returns true for success, false for failure.

(Relevant only when running on a Microsoft Windows operating system.) Searches the Windows Local Machine and Current User registry-based certificate stores for a certificate having an MD5 or SHA1 thumbprint equal to the thumbprint. The hash (i.e. thumbprint) is passed as a string using the encoding specified by encoding (such as "base64", "hex", etc.).

Returns true for success, false for failure.

Loads an ASN.1 or DER encoded certificate represented in a Base64 string.

Returns true for success, false for failure.

Loads an X.509 certificate from data contained in certBytes.

Note: The certBytes may contain the certificate in any format. It can be binary DER (ASN.1), PEM, Base64, etc. Chilkat will automatically detect the format.

Returns true for success, false for failure.

Loads an X.509 certificate from ASN.1 DER encoded bytes.

Note: The data may contain the certificate in any format. It can be binary DER (ASN.1), PEM, Base64, etc. Chilkat will automatically detect the format.

Returns true for success, false for failure.

Loads a certificate from a .cer, .crt, .p7b, or .pem file. This method accepts certificates from files in any of the following formats:
1. DER encoded binary X.509 (.CER)
2. Base-64 encoded X.509 (.CER)
3. Cryptographic Message Syntax Standard - PKCS #7 Certificates (.P7B)
4. PEM format
This method decodes the certificate based on the contents if finds within the file, and not based on the file extension. If your certificate is in a file having a different extension, try loading it using this method before assuming it won't work. This method does not load .p12 or .pfx (PKCS #12) files.

Returns true for success, false for failure.

Important: It's important to set the SmartCardPin property before calling this method.

Loads a certificate and its associated private key (if available) from a connected USB token or smart card. This function works on Windows, Linux, MacOS, iOS, and Alpine Linux. If multiple USB tokens and/or smartcards are connected to the system, then each will be searched and the first matching certificate will be loaded.

The certSpec can have the following formats and values:

• Empty String: Passing the empty string is the most common way to call this function. Pass the empty string when only one HSM (USB token or smart card) is connected to the system, and it contains only one certificate with a private key. The HSM can contain other certificates, but Chilkat will automatically choose and load the certificate that has the associated private key also located on the HSM.
• cn=<cert subject common name>: Finds and loads the certificate having the specified subject common name (CN).
• subjectdn_withtags=<distinguished name with tags>: Finds and loads the certificate having the specified DN with tags. For example, subjectdn_withtags=C=US, O=Example Corporation, OU=IT Department, CN=www.example.com
• subjectdn=<distinguished name without tags>: Finds and loads the certificate having the specified DN without tags. For example, subjectdn=US, California, San Francisco, Example Corp, Engineering, www.example.com, support@example.com
• issuercn=<subject hex serial:issuer common name>: Finds and loads the certificate having the specified hex serial number and an issuer with the specified common name. For example, "01020304: Let's Encrypt Authority X1"
• serial=<hex serial number>: Finds and loads the certificate having the specified hexidecimal serial number.
• thumbprint=<hex SHA1 thumbprint>: Finds and loads the certificate having the specified hexidecimal SHA1 thumbprint.
• policyoid=<certificate policy OID>: Finds and loads the certificate having a policy OID equal to the specified value, such as 2.16.840.1.101.2.1.11.39.
• o=<subject organization>: Finds and loads the certificate having the "O" subject part equal to the specified value.
• c=<subject country>: Finds and loads the certificate having the "C" subject part equal to the specified value.
• l=<subject locality>: Finds and loads the certificate having the "L" subject part equal to the specified value.
• ou=<subject organizational unit>: Finds and loads the certificate having the "OU" subject part equal to the specified value.
• st=<subject state>: Finds and loads the certificate having the "ST" subject part equal to the specified value.
• e=<subject email>: Finds and loads the certificate having the "E" subject part equal to the specified value.

On Windows systems, certSpec can specify a CSP (Cryptographic Service Provider) name, such as "YubiHSM Key Storage Provider." This option is retained for legacy support, as Chilkat initially handled USB tokens and smartcards only on Windows via CSPs. Chilkat now supports HSMs across multiple platforms (Windows, Linux, macOS, iOS, Alpine Linux) and uses various methods to communicate with HSMs, including PKCS11, macOS Keychain services, Windows ScMinidriver, MsCNG, and legacy Windows CryptoAPI. Chilkat automatically detects the HSM make/model and selects the optimal communication method.

Some possible CSP values are:

• Microsoft Smart Card Key Storage Provider
• Microsoft Base Smart Card Crypto Provider
• Bit4id Universal Middleware Provider
• YubiHSM Key Storage Provider (starting in v9.5.0.83)
• SafeSign Standard Cryptographic Service Provider
• SafeSign Standard RSA and AES Cryptographic Service Provider
• eToken Base Cryptographic Provider
• cryptoCertum3 CSP
• FTSafe ePass1000 RSA Cryptographic Service Provider
• SecureStoreCSP
• EnterSafe ePass2003 CSP v2.0
• Gemalto Classic Card CSP
• PROXKey CSP India V1.0
• PROXKey CSP India V2.0
• TRUST KEY CSP V1.0
• Watchdata Brazil CSP V1.0
• Luna Cryptographic Services for Microsoft Windows
• Luna SChannel Cryptographic Services for Microsoft Windows
• Safenet RSA Full Cryptographic Provider
• nCipher Enhanced Cryptographic Provider
• MySmartLogon NFC CSP
• NFC Connector Enterprise
• ActivClient Cryptographic Service Provider
• EnterSafe ePass2003 CSP v1.0
• Oberthur Card Systems Cryptographic Provider
• Athena ASECard Crypto CSP
• many others...

Returns true for success, false for failure.

Loads the certificate from a PEM string.

Returns true for success, false for failure.

Loads the certificate from the PFX contained in pfxData. Note: If the PFX contains multiple certificates, the 1st certificate in the PFX is loaded.

Returns true for success, false for failure.

Loads a PFX from an in-memory image of a PFX file. Note: If the PFX contains multiple certificates, the 1st certificate in the PFX is loaded.

Returns true for success, false for failure.

Loads a PFX file. Note: If the PFX contains multiple certificates, the 1st certificate in the PFX is loaded.

Returns true for success, false for failure.

Loads the certificate from a completed asynchronous task.

Returns true for success, false for failure.

Converts a PEM file to a DER file.

Returns true for success, false for failure.

Saves a certificate object to a .cer file.

Returns true for success, false for failure.

Provides information for a cloud signing service to do the signing via a remote signing server. Current supported services are AWS KMS, Azure Key Vault, and ARSS (Aruba Remote Signing Service). See the examples below.

Returns true for success, false for failure.

Creates an asynchronous task to call the SetCloudSigner method with the arguments provided. (Async methods are available starting in Chilkat v9.5.0.52.)

Returns nil on failure

Initializes the certificate object from a base64 encoded string representation of the certificate's binary DER format.

Returns true for success, false for failure.

Used to associate a private key with the certificate for subsequent (PKCS7) signature creation or decryption.

Returns true for success, false for failure.

Same as SetPrivateKey, but the key is provided in unencrypted PEM format. (Note: The privKeyPem is not a file path, it is the actual PEM text.)

Returns true for success, false for failure.

This is an open-ended method to accomodate uploading the private key to a cloud service, such as AWS KMS, or Azure Key Vault. For details, see the examples below.

Returns true for success, false for failure.

Creates an asynchronous task to call the UploadToCloud method with the arguments provided. (Async methods are available starting in Chilkat v9.5.0.52.)

Returns nil on failure

Adds an XML certificate vault to the object's internal list of sources to be searched for certificates for help in building certificate chains and verifying the certificate signature to the trusted root.

Returns true for success, false for failure.

Verifies the certificate signature, as well as the signatures of all certificates in the chain of authentication to the trusted root. Returns true if all signatures are verified to the trusted root. Otherwise returns false.

Returns the base64 representation of an X509PKIPathv1 containing just the calling certificate. This is typically used in an X.509 Binary Security Token. It is a PKIPath that contains an ordered list of X.509 public certificates packaged in a PKIPath. The X509PKIPathv1 token type may be used to represent a certificate path. (This is sometimes used in XAdES signatures.)

Returns true for success, false for failure.