Edit

BCRYPT_DSA_KEY_BLOB_V2 structure (bcrypt.h)

  • Article

The BCRYPT_DSA_KEY_BLOB_V2 structure is used as a header for a Digital Signature Algorithm (DSA) public key or private key BLOB in memory.

Syntax

typedef struct _BCRYPT_DSA_KEY_BLOB_V2 {
  ULONG               dwMagic;
  ULONG               cbKey;
  HASHALGORITHM_ENUM  hashAlgorithm;
  DSAFIPSVERSION_ENUM standardVersion;
  ULONG               cbSeedLength;
  ULONG               cbGroupSize;
  UCHAR               Count[4];
} BCRYPT_DSA_KEY_BLOB_V2, *PBCRYPT_DSA_KEY_BLOB_V2;

Members

dwMagic

Determines the type of key this structure represents. This can be one of the following values.

Value Meaning
BCRYPT_DSA_PUBLIC_MAGIC_V2
0x32425044
 The structure represents a DSA public key.
BCRYPT_DSA_PRIVATE_MAGIC_V2
0x32565044
 The structure represents a DSA private key.

cbKey

The length, in bytes, of the key.

hashAlgorithm

A HASHALGORITHM_ENUM enumeration value that specifies the hashing algorithm to use.

standardVersion

A DSAFIPSVERSION_ENUM enumeration value that specifies the Federal Information Processing Standard (FIPS) to apply.

cbSeedLength

Length of the seed used to generate the prime number q in bytes.

cbGroupSize

Size of the prime number q in bytes. Currently, when the key exceeds 1024 bits in length, q is 32 bytes long.

Count[4]

The number of iterations performed to generate the prime number q from the seed. For more information, see NIST standard FIPS186-3.

Remarks

The structure applies to DSA keys that exceed 1024 bits in length but are less than or equal to 3072 bits.

This structure is used as a header for a larger buffer. A DSA public key BLOB (BCRYPT_DSA_PUBLIC_BLOB) has the following format in contiguous memory. The Seed, q, Modulus, Generator, and Public numbers are in big-endian format.


BCRYPT_DSA_KEY_BLOB_V2
Seed[cbSeedLength]  // Big-endian.
q[cbGroupSize]      // Big-endian.
Modulus[cbKey]      // Big-endian.
Generator[cbKey]    // Big-endian.
Public[cbKey]       // Big-endian.

A DSA private key BLOB (BCRYPT_DSA_PRIVATE_BLOB) has the following format in contiguous memory. The Seed, q, Modulus, Generator, Public, and PrivateExponent numbers are in big-endian format.


BCRYPT_DSA_KEY_BLOB_V2
Seed[cbSeedLength]              // Big-endian.
q[cbGroupSize]                  // Big-endian.
Modulus[cbKey]                  // Big-endian.
Generator[cbKey]                // Big-endian.
Public[cbKey]                   // Big-endian.
PrivateExponent[cbGroupSize]    // Big-endian.

Requirements

Requirement Value
Minimum supported client Windows 8 [desktop apps only]
Minimum supported server Windows Server 2012 [desktop apps only]
Header bcrypt.h

See also

BCryptExportKey

BCryptImportKeyPair