kcapi_akcipher_setkey - Man Page

set the private key for the cipher handle

Synopsis

int kcapi_akcipher_setkey(struct kcapi_handle * handle, const uint8_t * key, uint32_t keylen);

Arguments

handle

[in] cipher handle

key

[in] key buffer in DER format

keylen

[in] length of key buffer

Description

With this function, the caller sets the key for subsequent cipher operations​.

The key must be in DER format as follows

SEQUENCE { version INTEGER, n INTEGER ({ rsa_get_n }), e INTEGER ({ rsa_get_e }), d INTEGER ({ rsa_get_d }), prime1 INTEGER, prime2 INTEGER, exponent1 INTEGER, exponent2 INTEGER, coefficient INTEGER }

After the caller provided the key, the caller may securely destroy the key as it is now maintained by the kernel​.

return upon success the value of the maximum size for the asymmetric operation is returned (e​.g​. the modulus size); a negative errno-style error code if an error occurred

Author

Stephan Mueller <​smueller@chronox.de​>

Author.

Info

August 2026 libkcapi Manual 1.5.1 Programming Interface