Asymmetric Cipher Algorithm Definitions¶
-
struct
akcipher_request
¶ public key request
Definition
struct akcipher_request {
struct crypto_async_request base;
struct scatterlist *src;
struct scatterlist *dst;
unsigned int src_len;
unsigned int dst_len;
void *__ctx[];
};
Members
base
- Common attributes for async crypto requests
src
- Source data
dst
- Destination data
src_len
- Size of the input buffer
dst_len
- Size of the output buffer. It needs to be at least as big as the expected result depending on the operation After operation it will be updated with the actual size of the result. In case of error where the dst sgl size was insufficient, it will be updated to the size required for the operation.
__ctx
- Start of private context data
-
struct
akcipher_alg
¶ generic public key algorithm
Definition
struct akcipher_alg {
int (*sign)(struct akcipher_request *req);
int (*verify)(struct akcipher_request *req);
int (*encrypt)(struct akcipher_request *req);
int (*decrypt)(struct akcipher_request *req);
int (*set_pub_key)(struct crypto_akcipher *tfm, const void *key, unsigned int keylen);
int (*set_priv_key)(struct crypto_akcipher *tfm, const void *key, unsigned int keylen);
unsigned int (*max_size)(struct crypto_akcipher *tfm);
int (*init)(struct crypto_akcipher *tfm);
void (*exit)(struct crypto_akcipher *tfm);
unsigned int reqsize;
struct crypto_alg base;
};
Members
sign
- Function performs a sign operation as defined by public key algorithm. In case of error, where the dst_len was insufficient, the req->dst_len will be updated to the size required for the operation
verify
- Function performs a sign operation as defined by public key algorithm. In case of error, where the dst_len was insufficient, the req->dst_len will be updated to the size required for the operation
encrypt
- Function performs an encrypt operation as defined by public key algorithm. In case of error, where the dst_len was insufficient, the req->dst_len will be updated to the size required for the operation
decrypt
- Function performs a decrypt operation as defined by public key algorithm. In case of error, where the dst_len was insufficient, the req->dst_len will be updated to the size required for the operation
set_pub_key
- Function invokes the algorithm specific set public key function, which knows how to decode and interpret the BER encoded public key
set_priv_key
- Function invokes the algorithm specific set private key function, which knows how to decode and interpret the BER encoded private key
max_size
- Function returns dest buffer size required for a given key.
init
- Initialize the cryptographic transformation object. This function is used to initialize the cryptographic transformation object. This function is called only once at the instantiation time, right after the transformation context was allocated. In case the cryptographic hardware has some special requirements which need to be handled by software, this function shall check for the precise requirement of the transformation and put any software fallbacks in place.
exit
- Deinitialize the cryptographic transformation object. This is a counterpart to init, used to remove various changes set in init.
reqsize
- Request context size required by algorithm implementation
base
- Common crypto API algorithm data structure
Asymmetric Cipher API¶
The Public Key API is used with the algorithms of type CRYPTO_ALG_TYPE_AKCIPHER (listed as type “akcipher” in /proc/crypto)
-
struct crypto_akcipher *
crypto_alloc_akcipher
(const char * alg_name, u32 type, u32 mask)¶ allocate AKCIPHER tfm handle
Parameters
const char * alg_name
- is the cra_name / name or cra_driver_name / driver name of the public key algorithm e.g. “rsa”
u32 type
- specifies the type of the algorithm
u32 mask
- specifies the mask for the algorithm
Description
Allocate a handle for public key algorithm. The returned struct crypto_akcipher is the handle that is required for any subsequent API invocation for the public key operations.
Return
- allocated handle in case of success;
IS_ERR()
is true in case - of an error,
PTR_ERR()
returns the error code.
-
void
crypto_free_akcipher
(struct crypto_akcipher * tfm)¶ free AKCIPHER tfm handle
Parameters
struct crypto_akcipher * tfm
- AKCIPHER tfm handle allocated with
crypto_alloc_akcipher()
-
unsigned int
crypto_akcipher_maxsize
(struct crypto_akcipher * tfm)¶ Get len for output buffer
Parameters
struct crypto_akcipher * tfm
- AKCIPHER tfm handle allocated with
crypto_alloc_akcipher()
Description
Function returns the dest buffer size required for a given key. Function assumes that the key is already set in the transformation. If this function is called without a setkey or with a failed setkey, you will end up in a NULL dereference.
-
int
crypto_akcipher_encrypt
(struct akcipher_request * req)¶ Invoke public key encrypt operation
Parameters
struct akcipher_request * req
- asymmetric key request
Description
Function invokes the specific public key encrypt operation for a given public key algorithm
Return
zero on success; error code in case of error
-
int
crypto_akcipher_decrypt
(struct akcipher_request * req)¶ Invoke public key decrypt operation
Parameters
struct akcipher_request * req
- asymmetric key request
Description
Function invokes the specific public key decrypt operation for a given public key algorithm
Return
zero on success; error code in case of error
-
int
crypto_akcipher_sign
(struct akcipher_request * req)¶ Invoke public key sign operation
Parameters
struct akcipher_request * req
- asymmetric key request
Description
Function invokes the specific public key sign operation for a given public key algorithm
Return
zero on success; error code in case of error
-
int
crypto_akcipher_verify
(struct akcipher_request * req)¶ Invoke public key verify operation
Parameters
struct akcipher_request * req
- asymmetric key request
Description
Function invokes the specific public key verify operation for a given public key algorithm
Return
zero on success; error code in case of error
-
int
crypto_akcipher_set_pub_key
(struct crypto_akcipher * tfm, const void * key, unsigned int keylen)¶ Invoke set public key operation
Parameters
struct crypto_akcipher * tfm
- tfm handle
const void * key
- BER encoded public key
unsigned int keylen
- length of the key
Description
Function invokes the algorithm specific set key function, which knows how to decode and interpret the encoded key
Return
zero on success; error code in case of error
-
int
crypto_akcipher_set_priv_key
(struct crypto_akcipher * tfm, const void * key, unsigned int keylen)¶ Invoke set private key operation
Parameters
struct crypto_akcipher * tfm
- tfm handle
const void * key
- BER encoded private key
unsigned int keylen
- length of the key
Description
Function invokes the algorithm specific set key function, which knows how to decode and interpret the encoded key
Return
zero on success; error code in case of error
Asymmetric Cipher Request Handle¶
-
struct akcipher_request *
akcipher_request_alloc
(struct crypto_akcipher * tfm, gfp_t gfp)¶ allocates public key request
Parameters
struct crypto_akcipher * tfm
- AKCIPHER tfm handle allocated with
crypto_alloc_akcipher()
gfp_t gfp
- allocation flags
Return
allocated handle in case of success or NULL in case of an error.
-
void
akcipher_request_free
(struct akcipher_request * req)¶ zeroize and free public key request
Parameters
struct akcipher_request * req
- request to free
-
void
akcipher_request_set_callback
(struct akcipher_request * req, u32 flgs, crypto_completion_t cmpl, void * data)¶ Sets an asynchronous callback.
Parameters
struct akcipher_request * req
- request that the callback will be set for
u32 flgs
- specify for instance if the operation may backlog
crypto_completion_t cmpl
- callback which will be called
void * data
- private data used by the caller
Description
Callback will be called when an asynchronous operation on a given request is finished.
-
void
akcipher_request_set_crypt
(struct akcipher_request * req, struct scatterlist * src, struct scatterlist * dst, unsigned int src_len, unsigned int dst_len)¶ Sets request parameters
Parameters
struct akcipher_request * req
- public key request
struct scatterlist * src
- ptr to input scatter list
struct scatterlist * dst
- ptr to output scatter list
unsigned int src_len
- size of the src input scatter list to be processed
unsigned int dst_len
- size of the dst output scatter list
Description
Sets parameters required by crypto operation