Provided by: libibverbs-dev_39.0-1_amd64 
NAME
mlx5dv_dek_create - Creates a DEK
mlx5dv_dek_query - Queries a DEK’s attributes
mlx5dv_dek_destroy - Destroys a DEK
SYNOPSIS
#include <infiniband/mlx5dv.h>
struct mlx5dv_dek *mlx5dv_dek_create(struct ibv_context *context,
struct mlx5dv_dek_init_attr *init_attr);
int mlx5dv_dek_query(struct mlx5dv_dek *dek, struct mlx5dv_dek_attr *attr);
int mlx5dv_dek_destroy(struct mlx5dv_dek *dek);
DESCRIPTION
Data Encryption Keys (DEKs) are used to encrypt and decrypt transmitted data. After a DEK is created, it
can be configured in MKeys for crypto offload operations. DEKs are not persistent and are destroyed upon
process exit. Therefore, software process needs to re-create all needed DEKs on startup.
mlx5dv_dek_create() creates a new DEK with the attributes specified in init_attr. A pointer to the newly
created dek is returned, which can be used for DEK query, DEK destruction and when configuring a MKey for
crypto offload operations. An active crypto login session must be present in order to create a DEK.
To use the created DEK in a MKey, a valid or active crypto login session is not needed. Revoking the im‐
port KEK or credential that were used during the login (and therefore rendering the login session in‐
valid) does not prevent using a created DEK.
mlx5dv_dek_query() queries the DEK specified by dek and returns the queried attributes in attr. An ac‐
tive crypto login session must be present in order to query a DEK.
mlx5dv_dek_destroy() destroys the DEK specified by dek.
ARGUMENTS
context
The device context to create the DEK with. context must have an active crypto login session associated
with in order to create the DEK.
init_attr
struct mlx5dv_dek_init_attr {
enum mlx5dv_crypto_key_size key_size;
bool has_keytag;
enum mlx5dv_crypto_key_purpose key_purpose;
struct ibv_pd *pd;
char opaque[8];
char key[128];
uint64_t comp_mask;
};
key_size
The size of the key, can be one of the following
MLX5DV_CRYPTO_KEY_SIZE_128
Key size is 128 bit.
MLX5DV_CRYPTO_KEY_SIZE_256
Key size is 256 bit.
has_keytag
Whether the DEK has a keytag or not. If set, the key should include a 8 Bytes keytag. Keytag is
used to verify that the DEK being used by a MKey is the expected DEK. This is done by comparing
the keytag that was defined during DEK creation with the keytag provided in the MKey crypto con‐
figuration, and failing the operation if they are different.
key_purpose
The purpose of the key, currently can only be the following value
MLX5DV_CRYPTO_KEY_PURPOSE_AES_XTS
The key will be used for AES-XTS crypto engine.
pd The protection domain to be associated with the DEK.
opaque Plaintext metadata to describe the key.
key The key that will be used for encryption and decryption of transmitted data. Must be provided
wrapped by the import KEK that was specified for the crypto login session. Actual size and layout
of this field depend on the provided key_size and has_keytag fields. key should be constructed
according to the following table.
DEK key Field Construction.
Key size Has Keytag Key Layout
─────────────────────────────────────────────────────
128 Bit No ENC(iv_64b + key1_128b +
key2_128b)
256 Bit No ENC(iv_64b + key1_256b +
key2_256b)
128 Bit Yes ENC(iv_64b + key1_128b +
key2_128b + 64b_keytag)
256 Bit Yes ENC(iv_64b + key1_256b +
key2_256b + 64b_keytag)
Where ENC() is AES key wrap algorithm and iv_64b is 0xA6A6A6A6A6A6A6A6 as per the AES key wrap
spec.
The following example shows how to wrap a 128 bit key that has keytag using a 128 bit import KEK
in OpenSSL:
unsigned char import_kek[16]; /* 128 bit import KEK in plaintext for wrapping */
unsigned char iv[8] = {0xA6, 0xA6, 0xA6, 0xA6, 0xA6, 0xA6, 0xA6, 0xA6};
/*
* Indexes 0-15 are key1 in plaintext, indexes 16-31 are key2 in plaintext,
* and indexes 32-39 are key_tag in plaintext.
*/
unsigned char key[40];
unsigned char wrapped_key[48];
EVP_CIPHER_CTX *ctx;
int len;
ctx = EVP_CIPHER_CTX_new();
EVP_CIPHER_CTX_set_flags(ctx, EVP_CIPHER_CTX_FLAG_WRAP_ALLOW);
EVP_EncryptInit_ex(ctx, EVP_aes_128_wrap(), NULL, import_kek, iv);
EVP_EncryptUpdate(ctx, wrapped_key, &len, key, sizeof(key));
EVP_EncryptFinal_ex(ctx, wrapped_key + len, &len);
EVP_CIPHER_CTX_free(ctx);
comp_mask
Reserved for future extension, must be 0 now.
dek
Pointer to an existing DEK to query or to destroy.
attr
DEK attributes to be populated when querying a DEK.
struct mlx5dv_dek_attr {
enum mlx5dv_dek_state state;
char opaque[8];
uint64_t comp_mask;
};
state The state of the DEK, can be one of the following
MLX5DV_DEK_STATE_READY
The key is ready for use. This is the state of the key when it is first created.
MLX5DV_DEK_STATE_ERROR
The key is unusable. The key needs to be destroyed and re-created in order to be used.
This can happen, for example, due to DEK memory corruption.
opaque Plaintext metadata to describe the key.
comp_mask
Reserved for future extension, must be 0 now.
RETURN VALUE
mlx5dv_dek_create() returns a pointer to a new struct mlx5dv_dek on success. On error NULL is returned
and errno is set.
mlx5dv_dek_query() returns 0 on success and updates attr with the queried DEK attributes. On error errno
value is returned.
mlx5dv_dek_destroy() returns 0 on success and errno value on error.
SEE ALSO
mlx5dv_crypto_login(3)
AUTHORS
Avihai Horon <avihaih@nvidia.com>
mlx5dv_dek_create / mlx5...uery / mlx5dv_dek_destroy(3)