SignedDataStream (6.0 API Documentation)

java.lang.Object
- iaik.pkcs.pkcs7.SignedDataStream

All Implemented Interfaces:

ContentStream, EOFListener, java.util.EventListener

Direct Known Subclasses:

SignedAndEnvelopedDataStream, SignedData
```
public class SignedDataStream
extends java.lang.Object
implements ContentStream, EOFListener
```
This class represents the stream-implementation of the PKCS#7 content type SignedData.
Each PKCS#7 content type is associated with a specific object identifier, derived from:
```
 pkcs-7 OBJECT IDENTIFIER ::=
   { iso(1) member-body(2) US(840) rsadsi(113549)
       pkcs(1) 7 }
 
```
The object identifier for the SignedData content type is defined as:
signedData OBJECT IDENTIFIER ::= { pkcs-7 2 }
which corresponds to the OID string "1.2.840.1.113549.1.7.2".
The PKCS#7 Cryptographic Message Standard specifies the SignedData content type for providing a syntax for building digital signatures. Content of any type may be signed by any number of signers in parallel. For each signer, a message digest is computed on the content (and any additional authenticating information) with a signer-specific message-digest algorithm. Subsequently, again for each signer, the corresponding message digest from the previous step is encrypted with the particular signer's private key and - together with some signer-specific information - collected into aSignerInfo value. Finally all created SignerInfo values are collected together with the content for forming a SignedData structure.
This class implements the SignedData structure resulting from the last step described above. The SignedData type is defined as ASN.1 SEQUENCE type containing the following components (see PKCS#7 specification, Version 1.5; notice that the ASN.1 module printed below not fully agrees with the SignedData definition of Version 1.5, since the certificates field is interpreted as SET OF pure X.509 certificates, whereas Version 1.5 also allows PKCS#6 extended certificates!):
```
 SignedData ::= SEQUENCE {
   version           Version,
   digestAlgorithms  DigestAlgorithmIdentifiers,
   contentInfo       ContentInfo,
   certificates      [0] IMPLICIT Certificates OPTIONAL,
   crls              [1] IMPLICIT CertificateRevocationLists OPTIONAL,
   signerInfos       SignerInfos }
 

 DigestAlgorithmIdentifiers ::= SET OF DigestAlgorithmIdentifier
 

 Certificates ::= SET OF Certificate -- X.509
 

 CertificateRevocationLists ::= SET OF CertificateRevocationList
 

 SignerInfos ::= SET OF SignerInfo
 
```
The digestAlgorithms field contains the object identifiers of the message digest algorithms used by the several signers for digesting the content that is supplied in the contentInfo field. The optional certificates field shall contain certificate chains for all the signers of the signerInfos field. The optional crls field may supply information about the revocation status of the certificates specified in the certificates field. And finally, the signerInfos field collects per-signer information for all parciticipated signers including the encrypted digests of the content (i.e. the signer-specific digital signatures of the content).
If there are no signers on the content, the signed-data content type may be used for disseminating certificates and certificate-revocation lists.
Verifying some received signature(s) is done by decrypting the encrypted message digests for each signer with the signer's public key and comparing the results with independently computed message digests on the original content.
For more information consult the RSA PKCS#7 specification.
The SignedData version implemented by this class complies with the SignedData structure as used by the S/MIME protocol. In this way, the digest is calculated on only the content octets of the DER encoding of the content field of the inherent ContentInfo structure. At this point it is important to note that currently IAIK-JCE only supports SignedData structures to be used for signing content values of the PKCS#7 Data content type!

When creating a SignedDataStream object for the content to be signed by using the SignedDataStream(InputStream is, int mode) constructor, additionally the transmission mode has to be specified. If the mode is set to SignedDataStream.IMPLICIT the raw data will be included in the SignedData message to be transmitted, but it will be not included if the mode is set to SignedDataStream.EXPLICIT. However, in both cases the raw data has to be supplied when creating the SignedDataStream object, because it is needed for the digest computation:
```
 InputSrteam[] data_stream = ...; // the raw data supplying input stream
 SignedDataStream signed_data = new SignedDataStream(data_stream, SignedDataStream.IMPLICIT);
 
```
respectively
```
 SignedDataStream signed_data_stream = new SignedDataStream(data_stream,
     SignedDataStream.EXPLICIT);
 
```
In contrast to the non-stream-variant of the PKCS#7 SignedData type (implemented by the SignedData class), where explicit and implicit mode can be handled in the same way when creating a SignedData object, they require a different proceeding for the stream-supporting SignedDataStream class. In this way, the steps for creating a SignedDataStream object and preparing it for transmission can be summarized in the following way (to simplify matters, we will assume not to include certificate revocation lists):
1. Create a new SignedDataStream object thereby supplying the raw data to be signed as input stream and specifying the transmission mode to be used (either SignedDataStream.IMPLICIT or SignedDataStream.EXPLICIT):
```
     InputStream data_stream = ...;
     int mode = ...;
     SignedDataStream signed_data = new SignedDataStream(data_stream, mode);
 
```
2. Set the certificates of all the signers by calling the setCertificates method. The certificates are supplied as array of X509Certificates and shall contain chains from a known top-level CA to all the signers in the SignerInfo field:
```
 signed_data.setCertificates(certificates);
 
```
3. For each participated signer, create a SignerInfo object, optionally supply it with attributes, and add it to the SignedDataStream structure by calling the addSignerInfo method:
```
     SignerInfo signer1 = ...;
     signed_data.addSignerInfo(signer1);
     SignerInfo signer2 = ...;
     signed_data.addSignerInfo(signer2);
      ...
 
```
  You alternatively may collectively add all signers by utilizing the setSignerInfos method.
  When actually adding a SignerInfo the digest computation is initialized by wrapping a digest stream for the signer's particular digest algorithm around the data carrying input stream.
4. If the mode chosen in step 1 when creating the SignedDataStream object has been SignedDataStream.EXPLICIT, now get and read the data from the data carrying input stream. Since in explicit mode the raw data is not included in the SignedData message, the stream has to be read before actually performing the encoding. When reading the stream, the data is piped to all the signer specific digest streams for updating the hash computation.
```
 if (mode == SignedDataStream.EXPLICIT) {
   InputStream data_is = signed_data.getInputStream();
   byte[] buf = new byte[1024];
   int r;
   while ((r = data_is.read(buf)) > 0) {
     // do something useful
   }
 }
 
```
  When using the implicit mode, do not explicitly read data from the input stream at all! This will be done automatically during the last step when performing the encoding.
5. Use a proper writeTo method for BER encoding the the SignedDataStream object and writing it to an output stream. You optionally may specify a particular block size for splitting the data encoding:
```
     int blockSize = ...;
     signed_data.writeTo(output_stream, blockSize);
 
```
  respectively
```
 signed_data.writeTo(output_stream);
 
```
  It is recommended only to use the writeTo method where a particular block size (default 2048) can be specified, because it is the intended purpose of this stream-supporting SignedData implementation to handle large amounts of data. When a positive block size is specified for encoding the SignedData to a stream, the raw data is BER encoded as indefinite constructed octet string being composed of a series of definite primitive encoded octet strings of blockSize length, e.g.:
```
     0x24 0x80
               0x04 0x02 0x01 0xAB
               0x04 0x02 0x23 0x7F
               0x04 0x01 0xCA
     0x00 0x00
 
```
  instead of:
```
     0x04 0x05 0x01 0xAB 0x23 0x7F 0xCA
 
```
  for encoding the five data bytes 0x01 0xAB 0x23 0x7F 0xCA. The indefinite constructed encoding scheme also may be preferable when intending to be compatible to the encoding practice of some particular application (for instance some versions of Netscape Navigator).
Again, it has to be distinguished between IMPLICIT and EXPLICIT mode when using the SignedDataStream implementation for parsing a received SignedData message. When operating in IMPLICIT mode, the raw data is included in the received SignedData object, and so the parsing immediately may be performed when creating a SignedDataStream object from the DER encoded SignedData object by calling the SignedDataStream(InputStream is) constructor. On the other side, when the raw data has been transmitted outside the SignedData message (EXPLICIT mode), the SignedDataStream(InputStream data_is, AlgorithmID[] hashAlgorithms) constructor has to be used for initializing the new SignedDataStream object with raw data and hash algorithms to be used for digest computation; and the decoding has to be performed explicitly by calling the decode method. The initialization is necessary for preparing the digest computation on the raw data for the digest algorithms of all participated signers. Later, during signature verification the digest value computation is finished and the results are compared against the hash values resulting from decrypting the encrypted digests with the signer's public keys.
The individual steps necessary for parsing a received SignedData message and verifying the signatures may be summarized as follows:
1. If the InputStream supplies the BER encoding of an implicit SignedData object, use the SignedDataStream(InputStream is) constructor for creating a SignedDataStream object and implicitly performing the decoding:
```
 SignedDataStream signedData = new SignedDataStream(encoded_stream);
 
```
  On the other hand, if the BER encoding represents an explicit SignedData object, use the SignedDataStream(InputStream data_is, AlgorithmID[] hashAlgorithms) constructor for initializing a new SignedDataStream object with raw data and digest algorithms for hash computation (assuming that two hash algorithms are used: SHA and RIPEMD160):
```
 AlgorithmID[] algIDs = { ... };
 SignedDataStream signedData = new SignedDataStream(data_is, algIDs);
 
```
2. Get the data carrying input stream and entirely read the data from the stream. This has to be performed for both implicit and explicit modes at exactly this state of the parsing procedure. In both cases the constructor has initialized the digest computation by wrapping digest streams around the raw data stream for all participated digest algorithms, either implicitly parsed from the supplied SignedData object, or explicitly supplied as an array of hash algorithm IDs. When now reading the stream, the data is piped through the digest streams for updating the hash computation:
```
 InputStream dataIs = signedData.getInputStream();
 byte[] buf = new byte[1024];
 int r;
 while ((r = dataIs.read(buf)) > 0) {
   // do something useful
 }
 
```
3. When dealing with an explicit message now explicitly perform the decoding by calling the decode method:
```
 signedData.decode(encoded_stream);
 
```
4. Get the SignerInfos from the SignedData object and perform the signature verification:
```
 // get the signer infos
 SignerInfo[] signer_infos = signed_data.getSignerInfos();
 // verify the signatures
 int numberOfSignerInfos = signer_infos.length;
 if (numberOfSignerInfos == 0) {
   System.out.println("Warning: Unsigned message (no SignerInfo included)!");  
 } else {
   for (int i = 0; i < numberOfSignerInfos; i++) {
     try {
       // verify the signature for SignerInfo at index i
       X509Certificate signer_cert = signed_data.verify(i);
       // if the signature is OK the certificate of the signer is returned
       System.out.println("Signature OK from signer: "
         + signer_cert.getSubjectDN());
     } catch (SignatureException ex) {
       // if the signature is not OK a SignatureException is thrown
       System.out.println("Signature ERROR from signer: "
         + signed_data
            .getCertificate(signer_infos[i].getIssuerAndSerialNumber())
            .getSubjectDN());
     }
   }  
 }
 
```
The simple example above verifies the correctness of the signature value(s) and dumps the result to System.out. In practice an application will require some more sophisticated error processing.
Version:

File Revision 55

See Also:
ContentStream, ContentInfoStream, SignerInfo, SignedData

Field Summary

Fields
Modifier and Type	Field and Description
`protected int`	`block_size` The block size for block oriented stream encoding.
`protected X509Certificate[]`	`certificates` Repository for the signer certificates.
`protected ContentInfoStream`	`content_info` The inherent ContentInfo.
`protected ObjectID`	`content_type` The content type.
`protected X509CRL[]`	`crls` Repository for any included CRLs.
`static int`	`EXPLICIT` Denotes a mode where the signed message is not transported within the Signature
`static int`	`IMPLICIT` Denotes a mode where the signed message is included in the Signature
`protected java.io.InputStream`	`input_stream` An InputStream holding the data.
`protected int`	`mode` The mode specifying if the signed message is included in the Signature (IMPLICIT), or if is not transported within the Signature (EXPLICIT).
`protected java.util.Vector`	`signer_infos` Repository for the SignerInfos.
`protected DerInputStream`	`this_object` An InputStream from which a DER encoded SignedData object is read.
`protected int`	`version` The version number, currently 1.

Constructor Summary

Constructors
Modifier	Constructor and Description
`protected`	`SignedDataStream()` Default constructor for dynamic object creation in ContentInfo.
	`SignedDataStream(java.io.InputStream is)` Creates a new SignedDataStream where the DER encoded data is read from the given InputStream.
	`SignedDataStream(java.io.InputStream data_is, AlgorithmID[] hashAlgorithms)` Creates a new SignedDataStream from an InputStream holding the content that has been transmitted by other means, and an array specifying the hash algorithms to be used for digesting.
	`SignedDataStream(java.io.InputStream data_is, int mode)` Creates a SignedDataStream object from an input stream supplying the data to be signed.
	`SignedDataStream(ObjectID contentType)` Creates a new SignedDataStream object without any content.

Method Summary

Methods
Modifier and Type	Method and Description
`void`	`addSignerInfo(SignerInfo signerInfo)` Adds a SignerInfo object to this SignedData.
`void`	`decode(java.io.InputStream is)` Reads and decodes the SignedDataStream from a DerInputStream.
`int`	`getBlockSize()` Gets the block size defining the length of each definite primitive encoded octet string component.
`X509Certificate`	`getCertificate(IssuerAndSerialNumber issuer)` Tries to find the certificate specified by an IssuerAndSerialNumber.
`X509Certificate[]`	`getCertificates()` Returns the certificates of the signers.
`ObjectID`	`getContentType()` Returns the content type this class implements.
`X509CRL[]`	`getCRLs()` Returns all the certificate-revocation lists included in this `SignedData` object.
`AlgorithmID[]`	`getDigestAlgorithms()` Returns a collection of message-digest algorithm identifiers.
`java.io.InputStream`	`getInputStream()` Returns an InputStream from where the signed content can be read.
`byte[]`	`getMessageDigest(AlgorithmID digestAlgorithm)` Returns the message digest calculated for a specific algorithm.
`int`	`getMode()` Returns the mode of this SignedData.
`byte[]`	`getSignedDigest(int signerInfoIndex)` Returns the message digest included in the authenticated attributes.
`SignerInfo[]`	`getSignerInfos()` Returns all the signer infos included in this `SignedData` object.
`int`	`getVersion()` Returns the syntax version number.
`void`	`notifyEOF()` This method implements the EOFListener interface for performing the final decoding.
`void`	`setBlockSize(int blockSize)` Sets the block size for defining the length of each definite primitive encoded octet string component.
`void`	`setCertificates(X509Certificate[] certificates)` Sets the certificates of the several signers.
`void`	`setCRLs(X509CRL[] crls)` Sets a set of certificate-revocation lists.
`void`	`setInputStream(java.io.InputStream is)` Sets the InputStream which holds the content to sign.
`void`	`setMessageDigest(AlgorithmID digestAlgorithm, byte[] digest)` This method can be used to set an externally calculated MessageDigest.
`void`	`setSignerInfos(SignerInfo[] signerInfos)` Sets a collection of per-signer information.
`ASN1Object`	`toASN1Object()` Returns this SignedDataStream as ASN1Object.
`protected ASN1Object`	`toASN1Object(int blockSize)` Returns this SignedData as ASN1Object where a constructed OCTET STRING is used for encoding the content.
`java.lang.String`	`toString()` Returns a string giving some information about this `SignedDataStream` object.
`java.lang.String`	`toString(boolean detailed)` Returns a string giving some - if requested - detailed information about this `SignedDataStream` object.
`X509Certificate`	`verify(int signerInfoIndex)` Verifies the signature that has been created by the `signerInfoIndex`'th signer.
`void`	`verify(java.security.PublicKey publicKey, int signerInfoIndex)` Uses the provided public key for verifying the signature that has been created by the `signerInfoIndex`'th signer.
`SignerInfo`	`verify(X509Certificate signerCertificate)` Uses the provided signer certificate for verifying the signature that has been created by the signer being owner of the certificate.
`void`	`writeTo(java.io.OutputStream os)` DER encodes and writes this object to the supplied output stream.
`void`	`writeTo(java.io.OutputStream os, int blockSize)` Writes this object to the supplied output stream where a constructed OCTET STRING is used for encoding the content.

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

- Field Detail
  - IMPLICIT
```
public static final int IMPLICIT
```
    Denotes a mode where the signed message is included in the Signature
    
    See Also:
    Constant Field Values
  - EXPLICIT
```
public static final int EXPLICIT
```
    Denotes a mode where the signed message is not transported within the Signature
    
    See Also:
    Constant Field Values
  - version
```
protected int version
```
    The version number, currently 1.
  - content_type
```
protected ObjectID content_type
```
    The content type.
  - content_info
```
protected ContentInfoStream content_info
```
    The inherent ContentInfo.
  - certificates
```
protected X509Certificate[] certificates
```
    Repository for the signer certificates.
  - crls
```
protected X509CRL[] crls
```
    Repository for any included CRLs.
  - signer_infos
```
protected java.util.Vector signer_infos
```
    Repository for the SignerInfos.
  - this_object
```
protected DerInputStream this_object
```
    An InputStream from which a DER encoded SignedData object is read.
  - input_stream
```
protected java.io.InputStream input_stream
```
    An InputStream holding the data.
  - mode
```
protected int mode
```
    The mode specifying if the signed message is included in the Signature (IMPLICIT), or if is not transported within the Signature (EXPLICIT).
  - block_size
```
protected int block_size
```
    The block size for block oriented stream encoding.
- Constructor Detail
  - SignedDataStream
```
protected SignedDataStream()
```
    Default constructor for dynamic object creation in ContentInfo. Shall not be used by an application for creating a SignedDataStream object. The block size is set to 2048.
  - SignedDataStream
```
public SignedDataStream(ObjectID contentType)
```
    Creates a new SignedDataStream object without any content. The content value to be signed has to be of the given content type and has to be supplied by other means.
    
    Parameters:
    contentType - the contentType of the data
  - SignedDataStream
```
public SignedDataStream(java.io.InputStream data_is,
                int mode)
```
    Creates a SignedDataStream object from an input stream supplying the data to be signed. The given mode specifies the way the raw data is transmitted. If the mode is SignedDataStream.IMPLICIT, the raw data is included in the SignedData message to be transmitted. If the mode is SignedDataStream.EXPLICIT, the raw data is not included in the SignedData object.
    
    Parameters:
    data_is - a stream holding the data to sign
    mode - IMPLICIT if the message shall be included in the DER encoding, EXPLICIT otherwise
  - SignedDataStream
```
public SignedDataStream(java.io.InputStream is)
                 throws PKCSParsingException,
                        java.io.IOException
```
    Creates a new SignedDataStream where the DER encoded data is read from the given InputStream.
    Do not use this constructor for supplying the content data to be signed. This constructor may be used by the recipient for parsing an already existing SignedDataStream object, supplied as DER encoding from an input stream, and may have been created by one of the writeTo methods.
    Use the SignedDataStream(InputStream data_is, int mode) constructor for supplying the content data to be signed when creating a SignedDataStream object.
    This constructor only shall be used for decoding a SignedData object with included raw data (implicit mode).
    To initialize a SignedDataStream object for parsing an explicit SignedData message where the raw data is not included, use the SignedDataStream(InputStream data_is, AlgorithmID[] hashAlgorithms) constructor, and perform the decoding explicitly by calling the decode method.
    
    Parameters:
    is - the InputStream holding a DER encoded PKCS#7 SignedData object
    
    Throws:
    
    java.io.IOException - if an I/O error occurs during reading from the InputStream
    
    PKCSParsingException - if an error occurs while parsing the object
  - SignedDataStream
```
public SignedDataStream(java.io.InputStream data_is,
                AlgorithmID[] hashAlgorithms)
                 throws java.io.IOException
```
    Creates a new SignedDataStream from an InputStream holding the content that has been transmitted by other means, and an array specifying the hash algorithms to be used for digesting.
    Do not use this constructor for supplying the content value to be signed. This constructor may be used by the recipient for initializing the digest computation for an already existing explicit SignedDataStream message where the raw data is not included. The initialization is done by wrapping a digest stream around the supplied raw data stream for any specified hash algorithm. Subsequently the hash values will be updated when reading the stream thereby piping the data through the digest streams. Later, during signature verification the digest computation is finished and the results are compared with the hash values derived from decrypting the encrypted digests with the signer's public keys.
    For an explicit message the actual decoding has to be performed by calling the decode method just after reading the data:
```
 // initialize for hash computation:
 SignedDataStream signedData = new SignedDataStream(data_is, hashAlgorithms);
 // read the stream thereby updating the hash values:
 InputStream dataIs = signed_data.getInputStream();
 byte[] buf = new byte[1024];
 int r;
 while ((r = dataIs.read(buf)) > 0) {
   // do something useful
 }
 // explicitly perform the decoding
 signedData.decode(encoded_stream);
 
```
    A sender shall use the SignedDataStream(InputStream data_is, int mode) constructor for supplying the content to be signed when creating a SignedDataStream object.
    For decoding an implicit SignedDataStream message, use the SignedDataStream(InputStream is) constructor.
    Parameters:
    data_is - the InputStream supplying the raw data which has been transmitted by other means
    hashAlgorithms - the hash algorithms used by the participated signers for digesting the content data
    
    Throws:
    
    java.io.IOException - if there is no implementation for the specified hash algorithm
- Method Detail
  - decode
```
public void decode(java.io.InputStream is)
            throws java.io.IOException,
                   PKCSParsingException
```
    Reads and decodes the SignedDataStream from a DerInputStream. If the supplied InputStream actually is not an instance of DerInputStream, internally a DerInputStream is created before parsing the data.
    This method implicitly is called from inside the corresponding constructor for decoding an received implicit SignedDataStream object where the raw data is included. This method has to be explicitly called for decoding a received explicit SignedDataStream object where the raw data is not included. Before calling this method for decoding an explicit message, a new SignedDataStream object has to be created by means of the SignedDataStream(InputStream data_is, AlgorithmID[] hashAlgorithms) constructor for initializing it for hash computation, and the data has to be read from the stream for updating the hash values:
```
 // initialize for hash computation:
 SignedDataStream signedData = new SignedDataStream(data_is, hashAlgorithms);
 // read the stream thereby updating the hash values:
 InputStream dataIs = signed_data.getInputStream();
 byte[] buf = new byte[1024];
 int r;
 while ((r = dataIs.read(buf)) > 0) {
   // do something useful
 }
 // explicitly perform the decoding
 signedData.decode(encoded_stream);
 
```
    Specified by:
    
    decode in interface ContentStream
    
    Parameters:
    is - the InputStream holding a DER encoded PKCS#7 SignedData object
    
    Throws:
    
    java.io.IOException - if an I/O error occurs during reading from the InputStream
    
    PKCSParsingException - if an error occurs while parsing the object
  - notifyEOF
```
public void notifyEOF()
               throws java.io.IOException
```
    This method implements the EOFListener interface for performing the final decoding. Since the certificates, crls, and signerInfos fields are located at the end of a SignedData structure, they only can be accessed after reading the data stream. For that reason, when starting the parsing of an implicit SignedData message only version, digestAlgorithms, and ContentInfo fields can be parsed before reading the data. Since the data is supplied from an input stream, a iaik.utils.NotifyEOFInputStream is wrapped around this raw data stream for indicating that the parsing procedure is to be notified when the stream actually has been read. At that point, the program executing automatically jumps to the actual notifyEOF method for finishing the decoding by parsing the remaining certificates, crls and signerInfos fields.
    For any application it is strongly recommended recommended not to explicitly call this method. This method only is qualified as public method since it implements the iaik.utils.EOFListener interface.
    
    Specified by:
    
    notifyEOF in interface EOFListener
    
    Throws:
    
    java.io.IOException - if an error occurs while parsing the stream
    See Also:
    EOFListener, NotifyEOFInputStream
  - getMode
```
public int getMode()
```
    Returns the mode of this SignedData.
    
    Returns:
    IMPLICIT or EXPLICIT
  - getMessageDigest
```
public byte[] getMessageDigest(AlgorithmID digestAlgorithm)
                        throws java.security.NoSuchAlgorithmException
```
    Returns the message digest calculated for a specific algorithm. This method implements the DigestProvider interface, and therefore has to be qualified as public method. However, there should be no necessity for an application to utilize this method. This method only is called from inside the SignerInfo class for obtaining the digest calculated on the content for the specified hash algorithm.
    It is strongly recommended not to explicitly call this method, since it actually finishes the digest computation for all hash values resulting from piping the data through the digest streams. This only has to be performed once and is done from inside the SignerInfo class!
    
    Parameters:
    digestAlgorithm - the hash algorithm to be used for digest computation
    
    Returns:
    the message digest calculated on the content for the given hash algorithm
    
    Throws:
    
    java.security.NoSuchAlgorithmException - if there is no message digest for the specified algorithm
  - setMessageDigest
```
public void setMessageDigest(AlgorithmID digestAlgorithm,
                    byte[] digest)
                      throws java.security.NoSuchAlgorithmException
```
    This method can be used to set an externally calculated MessageDigest. When having created a new SignedDataStream for signing some content, this method has to be called after having added the SignerInfos. If none of the SignerInfos uses the specified digest algorithm a NoSuchAlgorithmException is thrown and the digest cannot be added. On the parsing side a digest value can be set for any of the digest algorithms that are parsed from the digestAlgorithms field.
    
    Parameters:
    digestAlgorithm - the hash algorithm for which the digest shall be set
    digest - the new value for the message digest
    
    Throws:
    
    java.security.NoSuchAlgorithmException - if the specified digest algorithm is not by any of the SignerInfos of this SignedData
  - setBlockSize
```
public void setBlockSize(int blockSize)
```
    Sets the block size for defining the length of each definite primitive encoded octet string component. If the value of blockSize is smaller or equal to zero the whole data is encoded as definite primitive octet string. This method may be used for enforcing block encoding when wrapping the SignedData into a ContentInfo.
    
    Specified by:
    
    setBlockSize in interface ContentStream
    
    Parameters:
    blockSize - for defining the encoding scheme and setting the octet string component length, if positive
    See Also:
    OCTET_STRING
  - getBlockSize
```
public int getBlockSize()
```
    Gets the block size defining the length of each definite primitive encoded octet string component. If the value of blockSize is smaller or equal to zero the whole data is encoded as definite primitive octet string. This method may be used for enforcing block encoding when wrapping the EncryptedData into a ContentInfo.
    
    Specified by:
    
    getBlockSize in interface ContentStream
    
    Returns:
    blockSize defining the encoding scheme and setting the octet string component length, if positive
    See Also:
    OCTET_STRING
  - setInputStream
```
public void setInputStream(java.io.InputStream is)
```
    Sets the InputStream which holds the content to sign. This method could be useful for writing this object several times.
    
    Parameters:
    is - InputSteam holding the content to sign
  - getInputStream
```
public java.io.InputStream getInputStream()
```
    Returns an InputStream from where the signed content can be read.
    
    Returns:
    an InputSteam holding the signed content
  - getContentType
```
public ObjectID getContentType()
```
    Returns the content type this class implements.
    
    Specified by:
    
    getContentType in interface ContentStream
    
    Returns:
    ObjectID.pkcs7_signedData
  - setCertificates
```
public void setCertificates(X509Certificate[] certificates)
```
    Sets the certificates of the several signers.
    It is intended that the set be sufficient to contain chains from a recognized "root" to all of the signers in the signerInfo field.
    
    Parameters:
    certificates - the certificates of the signers as array of X509Certificate
  - setCRLs
```
public void setCRLs(X509CRL[] crls)
```
    Sets a set of certificate-revocation lists.
    The given CRLs supply information about the revocation status of the certificates specified in the certificates field.
    
    Parameters:
    crls - a set of certificate-revocation lists as array of X509CRLs
  - setSignerInfos
```
public void setSignerInfos(SignerInfo[] signerInfos)
                    throws java.security.NoSuchAlgorithmException
```
    Sets a collection of per-signer information.
    There may be any number of elements in the collection, including zero.
    
    Parameters:
    signerInfos - a collection of per-signer information
    
    Throws:
    
    java.security.NoSuchAlgorithmException - if there is no implementation for the message digest algorithm specified in one signerInfo
    See Also:
    SignerInfo
  - addSignerInfo
```
public void addSignerInfo(SignerInfo signerInfo)
                   throws java.security.NoSuchAlgorithmException
```
    Adds a SignerInfo object to this SignedData.
    This method not only adds the given SignerInfo, but also initializes the hash computation by wrapping a digest stream for the signer's hash algorithm around the data carrying input stream.
    
    Parameters:
    signerInfo - the SignerInfo to add
    
    Throws:
    
    java.security.NoSuchAlgorithmException - if there is no implementation for the message digest algorithm specified in the signerInfo
    See Also:
    SignerInfo
  - getVersion
```
public int getVersion()
```
    Returns the syntax version number. At this time version 1 is implemented.
    
    Returns:
    the version number
  - getDigestAlgorithms
```
public AlgorithmID[] getDigestAlgorithms()
```
    Returns a collection of message-digest algorithm identifiers.
    There may be any number of elements in the collection, including zero. The returned OIDs identify the digest algorithms used by the several signers.
    
    Returns:
    the message-digest AlgorithmIDs
  - getCertificates
```
public X509Certificate[] getCertificates()
```
    Returns the certificates of the signers.
    
    Returns:
    the certificates of the signers, or null if no certificates are included
  - verify
```
public void verify(java.security.PublicKey publicKey,
          int signerInfoIndex)
            throws java.security.SignatureException
```
    Uses the provided public key for verifying the signature that has been created by the signerInfoIndex'th signer.
    Note that this method does not perform any certificate verification.
    
    Parameters:
    signerInfoIndex - the index into the SignerInfos array for identifying the SignerInfo belonging to the signer whose signature has to be verified
    publicKey - the public key of the signer to verify the message
    
    Throws:
    
    java.security.SignatureException - if the signature turns out to be incorrect
  - verify
```
public X509Certificate verify(int signerInfoIndex)
                       throws java.security.SignatureException
```
    Verifies the signature that has been created by the signerInfoIndex'th signer.
    The signature is verified by using the specified signer's public key, which is get from the signer's certificate, derived from the certificatesfield.
    Verifying the signatures of all the signer's included into some specific SignedData object may be done by "looping" through all the included SignerInfos, e.g.:
```
 SignerInfo[] signer_infos = signed_data.getSignerInfos();
 int numberOfSignerInfos = signer_infos.length;
 if (numberOfSignerInfos == 0) {
   System.out.println("Warning: Unsigned message (no SignerInfo included)!");  
 } else {
   for (int i = 0; i < numberOfSignerInfos; i++) {
     try {
       // verify the signed data using the SignerInfo at index i
       X509Certificate signer_cert = signed_data.verify(i);
       // if the signature is OK the certificate of the signer is returned
       System.out.println("Signature OK from signer: "
           + signer_cert.getSubjectDN());
     } catch (SignatureException ex) {
       // if the signature is not OK a SignatureException is thrown
       System.out.println("Signature ERROR from signer: "
         + signed_data
             .getCertificate(signer_infos[i].getIssuerAndSerialNumber())
             .getSubjectDN());
     }
   }  
 }
 
```
    The simple example above verifies the correctness of the signature value(s) and dumps the result to System.out. In practice an application will require some more sophisticated error processing.
    Note that this method does not perform any certificate verification.
    Parameters:
    signerInfoIndex - the index into the SignerInfos array for identifying the SignerInfo belonging to the signer whose signature has to be verified
    
    Returns:
    the certificate of the signer, if its signature turns out to be correct; otherwise a SignaturException is thrown
    
    Throws:
    
    java.security.SignatureException - if the signature turns out to be incorrect
  - verify
```
public SignerInfo verify(X509Certificate signerCertificate)
                  throws java.security.SignatureException
```
    Uses the provided signer certificate for verifying the signature that has been created by the signer being owner of the certificate. This method may be used for verifying the signature of a signer in situations where there are no certificates sent with the SignedData object. Of course, it also may be used when the certificate is not empty. However, take in mind that you should not step through the entries of the certificates field for calling verify(cert) for any certificate presented there since there also may (shall) be included issuer certificates and certificate chains leading to some trusted root.
    Note that this method does not perform any certificate verification.
    
    Parameters:
    signerCertificate - the certificate of the signer whose signature should be verified
    
    Returns:
    the signerInfo belonging to the signer being owner of the given certificate
    
    Throws:
    
    java.security.SignatureException - if the signature turns out to be incorrect or there is no signer with the given certificate
  - getSignedDigest
```
public byte[] getSignedDigest(int signerInfoIndex)
                       throws PKCSException
```
    Returns the message digest included in the authenticated attributes. If the signed content is not included in the SignedData ASN.1 object this method can be used to get to message digest of the signed content.
    
    Parameters:
    signerInfoIndex - the index into the SignerInfos array for identifying the SignerInfo belonging to the signer whose message digest shall be returned
    
    Throws:
    
    PKCSException
  - getCertificate
```
public X509Certificate getCertificate(IssuerAndSerialNumber issuer)
                               throws PKCSException
```
    Tries to find the certificate specified by an IssuerAndSerialNumber.
    
    Parameters:
    issuer - the IssuerAndSerialNumber identifying the certificate to search for
    
    Returns:
    the X509Certificate belonging to the given IssuerAndSerialNumber, if detected; otherwise a PKCSException is thrown
    
    Throws:
    
    PKCSException - if the requested certificate cannot be found
  - getCRLs
```
public X509CRL[] getCRLs()
```
    Returns all the certificate-revocation lists included in this SignedData object.
    
    Returns:
    an array containing the certificate-revocation lists included into this SignedData object, or null if there are no CRLs included
    See Also:
    setCRLs(iaik.x509.X509CRL[])
  - getSignerInfos
```
public SignerInfo[] getSignerInfos()
```
    Returns all the signer infos included in this SignedData object.
    
    Returns:
    an array containing all the SignerInfo objects included into this SignedData, or null if there are no signers specified
  - toASN1Object
```
public ASN1Object toASN1Object()
                        throws PKCSException
```
    Returns this SignedDataStream as ASN1Object. Creates an ASN1 SEQUENCE object supplied with all the component values as defined in the PKCS#7 Cryptographic Message Standard specification.
    
    Specified by:
    
    toASN1Object in interface ContentStream
    
    Returns:
    this SignedDataStream as ASN1Object
    
    Throws:
    
    PKCSException - if the ASN1Object could not be created
  - toASN1Object
```
protected ASN1Object toASN1Object(int blockSize)
                           throws PKCSException
```
    Returns this SignedData as ASN1Object where a constructed OCTET STRING is used for encoding the content.
    
    Parameters:
    blockSize - the block size defining the encoding scheme - and specifying the length of each primitive encoded octet string component, if positive
    
    Throws:
    
    PKCSException - if the ASN1Object could not be created
  - writeTo
```
public void writeTo(java.io.OutputStream os)
             throws java.io.IOException
```
    DER encodes and writes this object to the supplied output stream. In implicit mode, whole the inherent data is encoded as one single primitive definite octet string:
```
 0x04 <length> <data>
 
```
    Parameters:
    os - the output stream to which this SignedDataStream shall be encoded
    
    Throws:
    
    java.io.IOException - if an error occurs when writing to the stream
  - writeTo
```
public void writeTo(java.io.OutputStream os,
           int blockSize)
             throws java.io.IOException
```
    Writes this object to the supplied output stream where a constructed OCTET STRING is used for encoding the content. If block size has a value > 0, in implicit mode the inherent raw data is encoded as constructed OCTET STRING. In this case the encoding is splitted according to the defined block size:
```
 0x24 0x80
           0x04 <blocksize> <data>
           0x04 <blocksize> <data>
           0x04 <blocksize> <data>
                ...
 0x00 0x00
 
```
    If the block size is not positive, whole the inherent data is encoded as one single primitive definite octet string:
```
 0x04 <length> <data>
 
```
    Parameters:
    os - the output stream to which this SignedData shall be written
    blockSize - the block size defining the encoding scheme - and specifying the length of each primitive encoded octet string component, if positive
    
    Throws:
    
    java.io.IOException - if an error occurs during writing the object
  - toString
```
public java.lang.String toString()
```
    Returns a string giving some information about this SignedDataStream object.
    
    Overrides:
    
    toString in class java.lang.Object
    
    Returns:
    the string representation
  - toString
```
public java.lang.String toString(boolean detailed)
```
    Returns a string giving some - if requested - detailed information about this SignedDataStream object.
    
    Specified by:
    
    toString in interface ContentStream
    
    Parameters:
    detailed - - whether or not to give detailed information
    
    Returns:
    the string representation

Class SignedDataStream

Field Summary

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Field Detail

IMPLICIT

EXPLICIT

version

content_type

content_info

certificates

crls

signer_infos

this_object

input_stream

mode

block_size

Constructor Detail

SignedDataStream

SignedDataStream

SignedDataStream

SignedDataStream

SignedDataStream

Method Detail

decode

notifyEOF

getMode

getMessageDigest

setMessageDigest

setBlockSize

getBlockSize

setInputStream

getInputStream

getContentType

setCertificates

setCRLs

setSignerInfos

addSignerInfo

getVersion

getDigestAlgorithms

getCertificates

verify

verify

verify

getSignedDigest

getCertificate

getCRLs

getSignerInfos

toASN1Object

toASN1Object

writeTo

writeTo

toString

toString