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Certificate-based encryption lets you encrypt a document
for specific recipients by means of public key technology. Various
recipients can be given different permissions for the document.
Many aspects of encryption are made possible by public key technology.
An algorithm is used to generate two large numbers, known as keys,
that have the following properties:
One key is used to encrypt a set of data. Subsequently,
only the other key can be used to decrypt the data.
It is impossible to distinguish one key from the other.
One of the keys acts as a user’s private key. It is important
that only the user has access to this key. The other key is the
user’s public key, which can be shared with others.
A public key certificate contains a user’s public key and identifying
information. The X.509 format is used for storing certificates.
Certificates are typically issued and digitally signed by a certificate
authority (CA), which is a recognized entity that provides a measure
of confidence in the validity of the certificate. Certificates have
an expiration date, after which they are no longer valid. In addition,
certificate revocation lists (CRLs) provide information about certificates that
were revoked prior to their expiration date. CRLs are published
periodically by certificate authorities. The revocation status of
a certificate can also be retrieved through Online Certificate Status
Protocol (OCSP) over the network.
注意： If you upload an encrypted PDF document to the
LiveCycle repository, it cannot decrypt the PDF document
and extract the XDP content. It is recommended that you do not encrypt
a document prior to uploading it to the LiveCycle repository.
(See Writing Resources.)
注意： Before you can encrypt a PDF document with a
certificate, you must ensure that you add the certificate to LiveCycle. A certificate is added using Administration Console or
programmatically using the Trust Manager API. (See Importing Credentials by using the Trust Manager API.)
Summary of stepsTo encrypt a PDF document with a certificate, perform the
following steps:
Include project files.
Create an Encryption Client API object.
Get a PDF document to encrypt.
Reference the certificate.
Set encryption run-time options.
Create a certificate-encrypted PDF document.
Save the encrypted PDF document as a PDF file.
Include project filesInclude the necessary files in your development
project. If you are creating a client application by using Java,
include the necessary JAR files. If you are using web services,
ensure that you include the proxy files.
The following JAR
files must be added to your project’s class path:
adobe-livecycle-client.jar
adobe-usermanager-client.jar
adobe-encryption-client.jar
adobe-utilities.jar (required if LiveCycle is deployed
on JBoss Application Server)
jbossall-client.jar (required if LiveCycle is deployed
on JBoss Application Server)
Create an Encryption Client API objectTo programmatically perform
an Encryption service operation, you must create an Encryption service
client. If you are using the Java Encryption Service API, create
an EncrytionServiceClient object. If you are using
the web service Encryption Service API, create an EncryptionServiceService object.
Get a PDF document to encryptYou must obtain an unencrypted
PDF document to encrypt. If you attempt to secure a PDF document
that is already encrypted, an exception is thrown.
Reference the certificateTo encrypt a PDF document with a certificate,
reference a certificate that is used to encrypt a PDF document.
The certificate is a .cer file, a .crt file, or a .pem file. A PKCS#12
file is used to store private keys with corresponding certificates.
When
encrypting a PDF document with a certificate, specify permissions that
are associated with the secured document. By specifying permissions,
you can control the actions that a user who opens a certificate-encrypted
PDF document can perform.
Set encryption run-time optionsSpecify the PDF document resources
to encrypt. You can encrypt the entire PDF document, everything
except the document’s metadata, or only the document’s attachments.
Create a certificate-encrypted PDF documentAfter you retrieve
an unsecured PDF document, reference the certificate, and set run-time
options, you can create a certificate-encrypted PDF document. After
the PDF document is encrypted, you need the corresponding public
key to decrypt it.
Save the encrypted PDF document as a PDF fileYou can save
the encrypted PDF document as a PDF file.
Encrypt a PDF document with a certificate using the Java APIEncrypt a PDF document with a certificate by using the
Encryption API (Java):
Include project files.
Include client JAR files,
such as adobe-encryption-client.jar, in your Java project’s class
path.
Create an Encryption Client API object.
Get a PDF document to encrypt.
Create a java.io.FileInputStream object
that represents the PDF document to encrypt by using its constructor
and passing a string value that specifies the location of the PDF
document.
Create a com.adobe.idp.Document object by
using its constructor and passing the java.io.FileInputStream object.
Reference the certificate.
Create a java.util.List object that
stores permission information by using its constructor.
Specify the permission associated with the encrypted document by
invoking the java.util.List object’s add method
and passing a CertificateEncryptionPermissions enumeration
value that represents the permissions that are granted to the user
who opens the secured PDF document. For example, to specify all permissions,
pass CertificateEncryptionPermissions.PKI_ALL_PERM.
Create a Recipient object by using its constructor.
Create a java.io.FileInputStream object
that represents the certificate that is used to encrypt the PDF document
by using its constructor and passing a string value that specifies the
location of the certificate.
Create a com.adobe.idp.Document object by
using its constructor and passing the java.io.FileInputStream object
that represents the certificate.
Invoke the Recipient object’s setX509Cert method
and pass the com.adobe.idp.Document object that
contains the certificate. (In addition, the Recipient object can
have a Truststore certificate alias or LDAP URL as a certificate source.)
Create a CertificateEncryptionIdentity object
that stores permission and certificate information by using its
constructor.
Invoke the CertificateEncryptionIdentity object’s setPerms method
and pass the java.util.List object that stores
permission information.
Invoke the CertificateEncryptionIdentity object’s setRecipient method
and pass the Recipient object that stores certificate
information.
Create a java.util.List object that stores
certificate information by using its constructor.
Invoke the java.util.List object’s add method
and pass the CertificateEncryptionIdentity object. (This java.util.List object
is passed as a parameter to the encryptPDFUsingCertificates method.)
Set encryption run-time options.
Create a CertificateEncryptionOptionSpec object by
invoking its constructor.
Specify the PDF document resources to encrypt by invoking
the CertificateEncryptionOptionSpec object’s setOption method
and passing a CertificateEncryptionOption enumeration value
that specifies the document resources to encrypt. For example, to encrypt
the entire PDF document, including its metadata and its attachments,
specify CertificateEncryptionOption.ALL.
Specify the Acrobat compatibility option by invoking the CertificateEncryptionOptionSpec object’s setCompat method
and passing a CertificateEncryptionCompatibility enumeration
value that specifies the Acrobat compatibility level. For example,
you can specify CertificateEncryptionCompatibility.ACRO_7.
Create a certificate-encrypted PDF document.
Encrypt
the PDF document with a certificate by invoking the EncryptionServiceClient object’s encryptPDFUsingCertificates method
and passing the following values:
The com.adobe.idp.Document object
that contains the PDF document to encrypt.
The java.util.List object that stores certificate
information.
The CertificateEncryptionOptionSpec object that
contains encryption run-time options.
The encryptPDFUsingCertificates method
returns a com.adobe.idp.Document object that contains
a certificate-encrypted PDF document.
Save the encrypted PDF document as a PDF file.
Create a java.io.File object and ensure
that the file name extension is .pdf.
Invoke the com.adobe.idp.Document object’s copyToFile method
to copy the contents of the com.adobe.idp.Document object
to the file. Ensure that you use the com.adobe.idp.Document object
that was returned by the encryptPDFUsingCertificates method.
Encrypt a PDF document with a certificate using the web service APIEncrypt a PDF document with a certificate by using the
Encryption API (web service):
Include project files.
Create a Microsoft .NET
project that uses MTOM. Ensure that you use the following WSDL definition: http://localhost:8080/soap/services/EncryptionService?WSDL&lc_version=9.0.1.
注意： Replace localhost with the IP
address of the server hosting LiveCycle.
Create an Encryption Client API object.
Create
an EncryptionServiceClient object by using its default
constructor.
Create an EncryptionServiceClient.Endpoint.Address object
by using the System.ServiceModel.EndpointAddress constructor.
Pass a string value that specifies the WSDL to the LiveCycle service (for example, http://localhost:8080/soap/services/EncryptionService?WSDL.)
You do not need to use the lc_version attribute.
This attribute is used when you create a service reference.)
Create a System.ServiceModel.BasicHttpBinding object
by getting the value of the EncryptionServiceClient.Endpoint.Binding field.
Cast the return value to BasicHttpBinding.
Set the System.ServiceModel.BasicHttpBinding object’s MessageEncoding field
to WSMessageEncoding.Mtom. This value ensures that
MTOM is used.
Enable basic HTTP authentication by performing the following tasks:
Assign the LiveCycle user name to the field EncryptionServiceClient.ClientCredentials.UserName.UserName.
Assign the corresponding password value to the field EncryptionServiceClient.ClientCredentials.UserName.Password.
Assign the constant value HttpClientCredentialType.Basic to
the field BasicHttpBindingSecurity.Transport.ClientCredentialType.
Assign the constant value BasicHttpSecurityMode.TransportCredentialOnly to
the field BasicHttpBindingSecurity.Security.Mode.
Get a PDF document to encrypt.
Create a BLOB object
by using its constructor. The BLOB object is used
to store a PDF document that is encrypted with a certificate.
Create a System.IO.FileStream object by
invoking its constructor and passing a string value that represents the
file location of the PDF document to encrypt and the mode in which
to open the file.
Create a byte array that stores the content of the System.IO.FileStream object.
You can determine the size of the byte array by getting the System.IO.FileStream object’s Length property.
Populate the byte array with stream data by invoking the System.IO.FileStream object’s Read method
and passing the byte array, the starting position, and the stream
length to read.
Populate the BLOB object by assigning its MTOM property
with the contents of the byte array.
Reference the certificate.
Create a Recipient object
by using its constructor. This object will store certificate information.
Create a BLOB object by using its constructor.
This BLOB object will store the certificate that
encrypts the PDF document.
Create a System.IO.FileStream object by
invoking its constructor and passing a string value that represents the
file location of the certificate and the mode in which to open the file.
Create a byte array that stores the content of the System.IO.FileStream object.
You can determine the size of the byte array by getting the System.IO.FileStream object’s Length property.
Populate the byte array with stream data by invoking the System.IO.FileStream object’s Read method
and passing the byte array, the starting position, and the stream
length to read.
Populate the BLOB object by assigning the contents
of the byte array to the BLOB object’s MTOM data
member.
Assign the BLOB object that stores the certificate
to the Recipient object’s x509Cert data
member.
Create a CertificateEncryptionIdentity object
that stores certificate information by using its constructor.
Assign the Recipient object that stores the
certificate to the CertificateEncryptionIdentity object’s
recipient data member.
Create an Object array and assign the CertificateEncryptionIdentity object
to the first element of the Object array. This Object array
is passed as a parameter to the encryptPDFUsingCertificates method.
Set encryption run-time options.
Create a CertificateEncryptionOptionSpec object by
using its constructor.
Specify the PDF document resources to encrypt by assigning
a CertificateEncryptionOption enumeration value
to the CertificateEncryptionOptionSpec object’s option data
member. To encrypt the entire PDF document, including its metadata
and its attachments, assign CertificateEncryptionOption.ALL to
this data member.
Specify the Acrobat compatibility option by assigning a CertificateEncryptionCompatibility enumeration
value to the CertificateEncryptionOptionSpec object’s compat data
member. For example, assign CertificateEncryptionCompatibility.ACRO_7 to
this data member.
Create a certificate-encrypted PDF document.
Encrypt
the PDF document with a certificate by invoking the EncryptionServiceService object’s encryptPDFUsingCertificates method
and passing the following values:
The BLOB object
that contains the PDF document to encrypt.
The Object array that stores certificate information.
The CertificateEncryptionOptionSpec object that
contains encryption run-time options.
The encryptPDFUsingCertificates method
returns a BLOB object that contains a certificate-encrypted
PDF document.
Save the encrypted PDF document as a PDF file.
Create a System.IO.FileStream object by
invoking its constructor and passing a string value that represents the
file location of the secured PDF document.
Create a byte array that stores the data content of the BLOB object
that was returned by the encryptPDFUsingCertificates method. Populate
the byte array by getting the value of the BLOB object’s binaryData data
member.
Create a System.IO.BinaryWriter object by
invoking its constructor and passing the System.IO.FileStream object.
Write the contents of the byte array to a PDF file by invoking
the System.IO.BinaryWriter object’s Write method
and passing the byte array.
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