Encrypt Data (QC3ENCDT, Qc3EncryptData) API

The Encrypt Data (OPM, QC3ENCDT; ILE, Qc3EncryptData) API protects data privacy by scrambling clear data into an unintelligible form. To recover the clear data from the encrypted data, use the Decrypt Data (OPM, QC3DECDT; ILE, Qc3DecryptData) API.

Information on cryptographic standards can be found in Create Algorithm Context (OPM, QC3CRTAX; ILE, Qc3CreateAlgorithmContext) API.

Authorities and Locks

Required device description authority

*USE

Required file authority

*OBJOPR, *READ

Required Parameter Group

Clear data

INPUT; CHAR(*)

The data to encrypt.
The format of the clear data is specified in the clear data format name parameter

Length of clear data

INPUT; BINARY(4)

For clear data format DATA0100, this is the length of the data to encrypt. For restrictions on the length of clear data, refer to the clear data length field below.
For clear data format DATA0200, this is the number of entries in the array.

Clear data format name

INPUT; CHAR(8)

The format of the clear data parameter.
The possible format names follow.

DATA0100

The clear data parameter contains the data to encrypt.

DATA0200

The clear data parameter contains an array of pointers and lengths to the data to encrypt.
See Clear Data Formats for a description of this format.

Algorithm description

INPUT; CHAR(*)

The algorithm and associated parameters for encrypting the data.
The format of the algorithm description is specified in the algorithm description format name parameter.

Algorithm description format name

INPUT; CHAR(8)

The format of the algorithm description.
The possible format names follow.

ALGD0100

The token for an algorithm context. This format must be used when performing the encrypt operation over multiple calls. After the last call (when the final operation flag is on), the context will reset to its initial state and can be used in another API. To create an algorithm context, use the Create Algorithm Context (OPM, QC3CRTAX; ILE, Qc3CreateAlgorithmContext) API.

ALGD0200

Parameters for a block cipher algorithm (DES, Triple DES, AES, and RC2).

ALGD0300

Parameters for a stream cipher algorithm (RC4-compatible).

ALGD0400

Parameters for a public key algorithm (RSA).

See Algorithm Description Formats for a description of these formats.

Key description

INPUT; CHAR(*)

The key to use for encrypting the data.
The format of the key description is specified in the key description format name parameter.
If the encrypt operation extends over multiple calls (see ALGD0100 description above), only the key description from the first call will be used. Therefore, on subsequent calls, you may set the pointer to this parameter to NULL.

Key description format name

INPUT; CHAR(8)

The format of the key description.
If the pointer to the key description parameter is NULL, this parameter will be ignored.
The possible format names follow.

KEYD0100

Key context token. This format identifies a key context. A key context is used to store a key value so it need not be recreated or retrieved every time it is used. To create a key context, use the Create Key Context (OPM, QC3CRTKX; ILE, Qc3CreateKeyContext) API.

KEYD0200

Key parameters.

KEYD0400

Keystore label. This format identifies a key from keystore. For more information on cryptographic services keystore, see the Cryptographic Services Keystore topic.

KEYD0500

PKCS5 passphrase. This format derives a key using RSA Data Security, Inc. Public-Key Cryptography Standard (PKCS) #5.

KEYD0600

PEM certificate. This format uses the PKA key in an ASCII encoded PEM based certificate.

KEYD0700

Certificate label. This format uses the public PKA key identified by a label into system certificate keystore (*SYSTEM).

KEYD0800

Distinguished name. This format uses the public PKA key identified by a distinguished name for a certificate in system certificate keystore (*SYSTEM).

KEYD0900

Application identifier. This format uses the private PKA key identified by an application identifier. The application identifier must be assigned to a valid certificate label in system certificate keystore (*SYSTEM).

See Key Description Formats for a description of these formats.

Cryptographic service provider

INPUT; CHAR(1)

The cryptographic service provider (CSP) that will perform the encryption operation.

0	Any CSP. The system will choose an appropriate CSP to perform the encryption operation.
1	Software CSP. The system will perform the encryption operation using software. If the requested algorithm is not available in software, an error is returned.
2	Hardware CSP. The system will perform the encryption operation using cryptographic hardware. If the requested algorithm is not available in hardware, an error is returned. A specific cryptographic device can be specified using the cryptographic device name parameter. If the cryptographic device is not specified, the system will choose an appropriate one.

Cryptographic device name

INPUT; CHAR(10)

The name of a cryptographic device description.
This parameter is valid when the cryptographic service provider parameter specifies 2 (hardware CSP). Otherwise, this parameter must be blanks or the pointer to this parameter set to NULL.

Encrypted data

OUTPUT; CHAR(*)

The area to store the encrypted data.

Length of area provided for encrypted data

INPUT; BINARY(4)

The length of the encrypted data parameter.
If the mode of operation is CFB 1-bit, this length must be specified in bits.
If the length of area provided for encrypted data is too small, an error will be generated and no data will be returned in the encrypted data parameter.

Block ciphers	The encrypted data parameter must be greater than or equal to the length of clear data. If padding and performing final processing, the encrypted data parameter must be large enough to include the pad characters. For more information, refer to the pad option description.
Stream ciphers	The encrypted data parameter must be greater than or equal to the length of clear data.
PKA ciphers	The encrypted data parameter must be greater than or equal to the key size.

Length of encrypted data returned

OUTPUT; BINARY(4)

The length of encrypted data returned in the encrypted data parameter.
If the mode of operation is CFB 1-bit, this length will be returned in bits.

Error code

I/O; CHAR(*)

The structure in which to return error information.
For the format of the structure, see Error code parameter.

Clear Data Formats

DATA0200 Format

Clear Data Formats Field Descriptions

Clear data length

The length of data to encrypt. Some cipher algorithms have restrictions on the clear data length.

DES, Triple DES, AES, RC2

When mode is 0 (ECB), 1 (CBC), 2 (OFB), or 5 (CFB 64-bit) and pad option is 0 (no pad), the total of the clear data lengths for the entire encrypt operation must be a multiple of the block length. For mode 3 (CFB 1-bit), the clear data length is specified in bits, not bytes.

RSA

For PKA block formats 0, 1, and 2, the clear data length must be at least 11 bytes shorter than the key size. For PKA block format 4, the data to encrypt must be shorter than or equal to the key size.

Clear data pointer

A space pointer to the data to encrypt.

Reserved

Must be null (binary 0s).

Algorithm Description Formats

ALGD0100 Format

ALGD0200 Format

ALGD0300 Format

ALGD0400 Format

Algorithm Description Formats Field Descriptions

Algorithm context token

A token for an algorithm context. The algorithm context is created by using the Create Algorithm Context (OPM, QC3CRTAX; ILE, Qc3CreateAlgorithmContext) API.

Block cipher algorithm

The encryption algorithm. Following are the valid block cipher algorithms.

20	DES
21	Triple DES
22	AES
23	RC2

Block length

The algorithm block length. For DES, Triple DES, and RC2 the block length field must specify 8. The valid block length values for AES are 16, 24, and 32.

Effective key size

For RC2, the number of key bits to use in the cipher operation. Valid values are from 1 to 1024. If RC2 is not specified for the block cipher algorithm, this field must be set to 0.

Final operation flag

The final processing indicator.

0

Continue. The system will not perform final processing and the algorithm context will maintain the state of the operation. The algorithm context can be used on future calls to this API to continue the encryption operation.

1

Final. The system will perform final processing (e.g. padding) and the algorithm context will reset to its initial state. The algorithm context can then be used to begin a new cryptographic operation (encrypt, decrypt, etc.). When performing a final operation, the pointer to the clear data parameter may be set to NULL and the length of clear data parameter set to 0. This option must be specified if performing RSA encryption.

Initialization vector or counter

An initialization vector (IV) is used for modes CBC, OFB, CFB, and CUSP. A counter is used for CTR mode. Refer to the mode standards for an explanation of how each mode uses the IV or counter. This field is not used for ECB mode, and must be set to NULL (binary 0s).
For DES, Triple DES, and RC2, the first 8 bytes are used as the IV/counter. For AES, the length is that specified by block length.
The IV/Counter need not be secret, but it should be unique for each message. For CBC, CFB, and CUSP modes, the IV must be significantly unique. If not unique, it may compromise security.
The IV can be any value. To obtain a good random IV or counter value, use the Generate Pseudorandom Numbers (OPM, QC3GENPRN; ILE, Qc3GenPRNs)API.

MAC length

This field is not used on an encrypt operation and must be set to null (binary 0s).

Mode

The mode of operation. Information on modes can be found in FIPS PUB 81, NIST Special Publication 800-38A, and ANSI X9.52. Following are the valid modes.

0	ECB.
1	CBC.
2	OFB. Not valid with AES or RC2.
3	CFB 1-bit. Not valid with AES or RC2.
4	CFB 8-bit. Not valid with AES or RC2.
5	CFB 64-bit. Not valid with AES or RC2.
6	CUSP. CUSP is a special type of CBC mode documented in the z/OS® ICSF Application Programmer's Guide (SA22-7522). It is used for handling data not a multiple of the block length. The length of encrypted data in CUSP mode will always equal the length of clear text data.
7	CTR. Only valid with AES.

Pad character

The pad character for pad option 1. Using hex 00 as the pad character is equivalent to ANSI X9.23 padding.

Pad option

If requested, padding is performed at the end of the encrypt operation. Be sure the encrypted data parameter is large enough to include any padding. The data will be padded up to the next block length byte multiple. For example, when using DES and total data to encrypt is 20, the text is padded to 24. The last byte is filled with a 1-byte binary counter containing the number of pad characters used. The preceeding pad characters are filled as specified by this field. Padding is not performed for modes CFB 1-bit, CFB 8-bit, and CUSP. In these cases, the pad option must be set to 0. Following are the valid pad options.

0	No padding is performed.
1	Use the character specified in the pad character field for padding.
2	The pad counter is used as the pad character. This is equivalent to PKCS #5 padding.

PKA block format

The public key algorithm block format. Following are the valid values.

0	PKCS #1 block type 00
1	PKCS #1 block type 01
2	PKCS #1 block type 02 This format is recommended when encrypting non-hash items (such as keys). The other formats are normally used in sign and verify functions.
4	Zero pad The clear data is placed in the low-order bit positions of a string of the same bit-length as the key modulus. All leading bits are set to zero.
6	OAEP

Public key cipher algorithm

The encryption algorithm. Following are the valid public key cipher algorithms.

50

RSA

Reserved

Must be null (binary 0s).

Signing hash algorithm

This field is not used on an encrypt operation and must be set to null (binary 0s).

Stream cipher algorithm

The encryption algorithm. Following are the valid stream cipher algorithms.

30	RC4-compatible

Key Description Formats

KEYD0100 Format

KEYD0200 Format

KEYD0400 Format

KEYD0500 Format

KEYD0600 Format

KEYD0700 Format

KEYD0800 Format

KEYD0900 Format

Key Description Formats Field Descriptions

Application identifer

The application ID assigned to a certificate with a private key in system certificate keystore (*SYSTEM).

Application identifier length

The length of the application ID. The length can not be greater than 32.

Certificate label

The label of the certificate in system certificate keystore (*SYSTEM). The certificate's public key will be used in the encryption operation.

Certificate label length

The length of the certificate label.

Derived key length

The length of key requested. The minimum allowed length is 1.

Distinguished name

The distinguished name of the certificate in system certificate keystore (*SYSTEM). The certificate's public key will be used in the encryption operation.

Distinguished name length

The length of the distinguished name.

File name

The name of a keystore file. Keystore files are created by using the Create Keystore (OPM, QC3CRTKS; ILE, Qc3CreateKeyStore) API.

Iteration count

Used to greatly increase the cost of an exhaustive search while modestly increasing the cost of key derivation. The minimum allowed value is 1. The standard recommends a minimum of 1000. The maximum allowed length is 100,000.

Key context token

A token for a key context. The key context is created by using the Create Key Context (OPM, QC3CRTKX; ILE, Qc3CreateKeyContext) API.

Key format

The format of the key string field. Following are the valid values.

0

Binary string. The key is specified as a binary value. To obtain a good random key value, use the Generate Symmetric Key (OPM, QC3GENSK; ILE, Qc3GenSymmetricKey) API or the Generate Pseudorandom Numbers (OPM, QC3GENRN; ILE, Qc3GenPRNs) API.

1

BER string If the key type field specifies 50 (RSA public), the key must be specified in BER encoded X.509 Certificate or SubjectPublicKeyInfo format. For specifications of this format, refer to RFC 3280. If the key type field specifies 51 (RSA private), the key must be specified in BER encoded PKCS #8 format. For specifications of this format, refer to RSA Security Inc. Public-Key Cryptography Standards. To generate a PKA key pair, use the Generate PKA Key Pair (OPM, QC3GENPK; ILE, Qc3GenPKAKeyPair) API.

Key string

The key to use in the encrypt operation.

Key string length

Length of the key string specified in the key string field.

Key type

The type of key. Following are the valid values.

20	DES The key string length or derived key string length must be 8 bytes. For key description KEYD0200, the key format must be 0. Only 7 bits of each byte are used as the actual key. The rightmost bit of each byte is used to set parity. Some cryptographic service providers require that a DES key have odd parity in every byte. Others ignore parity.
21	Triple DES The key string length or the derived key length can be 8, 16, or 24. For key description KEYD0200, the key format must be 0. Triple DES operates on an encryption block by doing a DES encrypt, followed by a DES decrypt, and then another DES encrypt. Therefore, it actually uses three 8-byte DES keys. If 24 bytes are supplied in the key string, the first 8 bytes are used for key 1, the second 8 bytes for key 2, and the third 8 bytes for key 3. If 16 bytes are supplied, the first 8 bytes are used for key 1 and key 3, and the second 8 bytes for key 2. If only 8 bytes are supplied, it will be used for all 3 keys (essentially making the operation equivalent to a single DES operation). Only 7 bits of each byte are used as the actual key. The rightmost bit of each byte is used to set parity. Some cryptographic service providers require that a Triple DES key have odd parity in every byte. Others ignore parity.
22	AES The key string length or derived key length can be 16, 24, or 32. For key description KEYD0200, the key format must be 0.
23	RC2 The key string length or derived key length can be from 1 to 128. For key description KEYD0200, the key format must be 0.
30	RC4-compatible The key string length or derived key length can be from 1 to 256. For key description KEYD0200, the key format must be 0. Because of the nature of the RC4-compatible algorithm, using the same key for more than one message will severely compromise security.
50	RSA public Valid only for key description KEYD0200. The key format must be 1. Encryption with a public key and decryption with a private key is used for data privacy.
51	RSA private Valid only for key description KEYD0200. The key format must be 1. Encryption with a private key and decryption with a public key is used for data authentication (e.g. signing).

Passphrase

A text string.

Passphrase CCSID

INPUT; BINARY(4)

The CCSID of the passphrase. The passphrase will be converted from the specified CCSID to Unicode before calling the PKCS5 algorithm.

0	The CCSID of the job is used to determine the CCSID of the data to be converted. If the job CCSID is 65535, the CCSID from the default CCSID (DFTCCSID) job attribute is used.
1-65533	A valid CCSID in this range is used. For a list of valid CCSIDs, see the i5/OS globalization topic collection.

Passphrase length

The length of passphrase. The length must be in the range of 1 to 256.

PEM certificate

An ASCII encoded PEM formated certificate.

PEM certificate length

The length of the PEM certificate.

Qualified keystore file name

The keystore file where the key is stored. Keystore files are created by using the Create Keystore (OPM, QC3CRTKS; ILE, Qc3CreateKeyStore) API. The first 10 characters contain the file name. The second 10 characters contain the name of the library where the keystore file is located. You can use the following special values for the library name.

*CURLIB	The job's current library is used to locate the keystore file. If no library is specified as the current library for the job, the QGPL library is used.
*LIBL	The job's library list is searched for the first occurence of the specified file name.

Record label

The label of a key record in a keystore file. The label will be converted from the job CCSID, or if 65535, the job default CCSID (DFTCCSID) job attribute to CCSID 1200 (Unicode UTF-16). Key records are created by using the Write Key Record (OPM, QC3WRTKR; ILE, Qc3WriteKeyRecord) API or the Generate Key Record (OPM, QC3GENKR; ILE, Qc3GenKeyRecord) API.

Reserved

Must be null (binary 0s).

Salt

Used to help thwart attacks by producing a large set of keys for each passphrase. The standard recommends the salt be generated at random and be at least 8 bytes long. You can use the Generate Pseudorandom Numbers (OPM, QC3GENPRN; ILE, Qc3GenPRNs) API to obtain a random value. Additionally, data that distinguishes between various operations can be added to the salt for additional security. Refer to the standard for more information.

Salt length

The length of salt. The length must be in the range of 1 to 16.

Error Messages

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