CKM_ECIES
This section provides a summary of CKM_ECIES.
Supported operations
| Operation | Supported |
|---|---|
| Encrypt and Decrypt | Yes (Single-part operation only) |
| Sign and Verify | No |
| SignRecover and VerifyRecover | No |
| Digest | No |
| Generate Key/Key-Pair | No |
| Wrap and Unwrap | No |
| Derive | No |
FIPS Mode support
| Available in FIPS Mode | Restrictions in FIPS Mode |
|---|---|
| No | Not applicable |
Key size range (bits) and parameters
| Key size minimum/maximum | Value |
|---|---|
| Minimum | 64 |
| Maximum | 571 |
Parameter
CK_ECIES_PARAM
Mechanism description
The Elliptic Curve Integrated Encryption Scheme (ECIES) mechanism, denoted CKM_ECIES, performs single-part encryption and decryption operations. The operations performed are as described in ANSI X9.63-2001.
This mechanism has a parameter, a CK_ECIES_PARAMS structure. This structure is defined as follows:
typedef struct CK_ECIES_PARAMS
{
CK_EC_DH_PRIMITIVE dhPrimitive;
CK_EC_KDF_TYPE kdf;
CK_ULONG ulSharedDataLen1;
CK_BYTE_PTR pSharedData1;
CK_EC_ENC_SCHEME encScheme;
CK_ULONG ulEncKeyLenInBits;
CK_EC_MAC_SCHEME macScheme;
CK_ULONG ulMacKeyLenInBits;
CK_ULONG ulMacLenInBits;
CK_ULONG ulSharedDataLen2;
CK_BYTE_PTR pSharedData2;
} CK_ECIES_PARAMS;
The fields of this structure have the following meanings:
| Field | Description |
|---|---|
| dhPrimitive | This is the Diffie-Hellman primitive used to derive the shared secret value. Valid value: CKDHP_STANDARD |
| kdf | This is the key derivation function used on the shared secret value. Valid value: CKD_SHA1_KDF |
| ulSharedDataLen1 | This is the length in bytes of the key derivation shared data. |
| pSharedData1 | This is the key derivation padding data shared between the two parties. |
| encScheme | This is the encryption scheme used to transform the input data. Valid value: CKES_XOR |
| ulEncKeyLenInBits | This is the bit length of the key to use for the encryption scheme. |
| macScheme | This is the MAC scheme used for MAC generation or validation. Valid values: CKMS_HMAC_SHA1 CKMS_SHA1 The MAC scheme |
| ulMacKeyLenInBits | This is the bit length of the key to use for the MAC scheme. |
| ulMacLenInBits | This is the bit length of the MAC scheme output. |
| ulSharedDataLen2 | This is the length in bytes of the MAC shared data. |
| pSharedData2 | This is the MAC padding data shared between the two parties. |
The pSharedData1 and pSharedData2 parameters are optional, and if not supplied then they must be NULL and the ulSharedDataLen1 and ulSharedDataLen2 parameters must be zero. With the MAC scheme CKMS_SHA1, any supplied shared data is ignored.
With the encryption scheme CKES_XOR, the ulEncKeyLenInBits parameter MUST be zero. With any other encryption scheme, the ulEncKeyLenInBits parameter must be set to the applicable key length in bits.
With the MAC scheme CKMS_SHA1, the ulMacKeyLenInBits parameter must be 0. With any other MAC scheme, the ulMacKeyLenInBits parameter must be a minimum of 80 bits, and a multiple of 8 bits.
The ulMacLenInBits parameter must be a minimum of 80 bits, a multiple of 8 bits, and not greater than the maximum output length for the specified Hash.
Constraints on key types and the length of the data are summarized in the following table.
ECIES: Key and Data Length
| Function | Key type | Input length | Output length |
|---|---|---|---|
| C_Encrypt | EC public key | Any length | 1 + 2modLen + any + macLen |
| C_Decrypt | EC private key | 1 + 2modLen + any + macLen | Any length |
Where:
-
modLen is the curve modulus length
-
macLen is the length of the produced MAC
The encrypted data is in the format QE||EncData||MAC, where:
-
QE is the uncompressed bit string of the ephemeral EC public key
-
EncData is the encrypted data
-
MAC is the generated MAC
Return to ProtectToolkit-C mechanisms.
