1KCAPI_CIPHER_STREAM_(3) Programming Interface KCAPI_CIPHER_STREAM_(3)
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6 kcapi_cipher_stream_update_last - send last data for processing
7 (stream)
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10 ssize_t kcapi_cipher_stream_update_last(struct kcapi_handle * handle,
11 struct iovec * iov,
12 size_t iovlen);
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15 handle
16 [in] cipher handle
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18 iov
19 [in] scatter/gather list with data to be processed by the cipher
20 operation.
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22 iovlen
23 [in] number of scatter/gather list elements.
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26 Using this function call, more plaintext for encryption or ciphertext
27 for decryption can be submitted to the kernel.
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29 This call is identical to the kcapi_cipher_stream_update call with the
30 exception that it marks the last data buffer before the cipher
31 operation is triggered. This is call is important for stream ciphers
32 like CTR or CTS mode when providing the last block. It is permissible
33 to provide a zero buffer if all data including the last block is
34 already provided by kcapi_cipher_stream_update.
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37 If this call is not made for stream ciphers with input data that is not
38 a multiple of the block size of the block cipher, the kernel will not
39 return the last block that contains less data than the block size of
40 the block cipher. For example, sending 257 bytes of data to be
41 encrypted with ctr(aes), the kernel will return only 256 bytes without
42 this call.
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44 return number of bytes sent to the kernel upon success; a negative
45 errno-style error code if an error occurred
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48 Stephan Mueller <smueller@chronox.de>
49 Author.
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52libkcapi Manual 1.4.0 August 2022 KCAPI_CIPHER_STREAM_(3)