ICspAlgorithm::get_IncrementLength method (certenroll.h)
The IncrementLength property retrieves a value, in bits, that can be used to determine valid incremental key lengths for algorithms that support multiple key sizes. This property is web enabled.
This property is read-only.
Syntax
HRESULT get_IncrementLength(
LONG *pValue
);
Parameters
pValue
Return value
None
Remarks
You can use the value of this property to determine valid key sizes for generated keys. For example, if the minimum key length of a DSA signing key is 512 bits, the maximum length is 1,024 bits, and the increment is 64 bits, valid key sizes include 512, 576, 640 and so in 64 bit increments up to 1,024.
The DefaultLength, IncrementLength, MaxLength, and MinLength properties can vary by algorithm and provider. The following table lists a few algorithms for which multiple key sizes can be set. The list is not inclusive.
| Algorithm OID | Cryptographic provider | Key length (bits) |
|---|---|---|
| XCN_OID_RSA_RSA(1.2.840.113549.1.1.1) |
Microsoft Smart Card Key Storage Provider
Microsoft Base Smart Card Crypto Provider |
Minimum: 1,024
Maximum: 4,096 Default: 1,024 Increment: 512 |
| XCN_OID_RSA_RSA(1.2.840.113549.1.1.1) |
Microsoft Software Key Storage Provider
Microsoft Base Cryptographic Provider v1.0 Microsoft Enhanced Cryptographic Provider v1.0 Microsoft Enhanced RSA and AES Cryptographic Provider Microsoft RSA Schannel Cryptographic Provider Microsoft Strong Cryptographic Provider |
Minimum: 384
Maximum: 16,384 Default: 1,024 Increment: 8 |
| XCN_OID_X957_DSA(1.2.840.10040.4.1) |
Microsoft Software Key Storage Provider
Microsoft Base DSS and Diffie-Hellman Cryptographic Provider Microsoft Base DSS Cryptographic Provider Microsoft DH Schannel Cryptographic Provider Microsoft Enhanced DSS and Diffie-Hellman Cryptographic Provider |
Minimum: 512
Maximum: 1,024 Default: 1,024 Increment: 64 |
| XCN_OID_ANSI_X942_DH(1.2.840.10046.2.1) | Diffie-Hellman key exchange algorithm. |
Minimum: 512
Maximum: 1,024 Default: 1,024 Increment: 64 |
| XCN_OID_ANSI_X942_DH(1.2.840.10046.2.1) |
Microsoft DH Schannel Cryptographic Provider
Microsoft Enhanced DSS and Diffie-Hellman Cryptographic Provider |
Minimum: 512
Maximum: 4,096 Default: 1,024 Increment: 64 |
| XCN_OID_RSA_RC2CBC(1.2.840.113549.3.2) |
Microsoft Software Key Storage Provider
Microsoft Smart Card Key Storage Provider Microsoft Base Smart Card Crypto Provider Microsoft DH Schannel Cryptographic Provider Microsoft Enhanced Cryptographic Provider v1.0 Microsoft Enhanced DSS and Diffie-Hellman Cryptographic Provider Microsoft Enhanced RSA and AES Cryptographic Provider Microsoft RSA Schannel Cryptographic Provider Microsoft Strong Cryptographic Provider |
Minimum: 40
Maximum: 128 Default: 128 Increment: 8 |
Requirements
| Requirement | Value |
|---|---|
| Minimum supported client | Windows Vista [desktop apps only] |
| Minimum supported server | Windows Server 2008 [desktop apps only] |
| Target Platform | Windows |
| Header | certenroll.h |
| DLL | CertEnroll.dll |