mbx_sm4_xts_encrypt/decrypt_mb16

Encrypts plaintext (xts_encrypt) and decrypts ciphertext (xts_decrypt).

Syntax

mbx_status16 mbx_sm4_xts_encrypt_mb16(int8u* pa_out[SM4_LINES], const int8u* pa_in[SM4_LINES], const int len[SM4_LINES], const mbx_sm4_key_schedule* key_sched1, const mbx_sm4_key_schedule* key_sched2, const int8u* pa_tweak[SM4_LINES]);

mbx_status16 mbx_sm4_xts_decrypt_mb16(int8u* pa_out[SM4_LINES], const int8u* pa_in[SM4_LINES], const int in_len[SM4_LINES], const mbx_sm4_key_schedule* key_sched1, const mbx_sm4_key_schedule* key_sched2, const int8u* pa_tweak[SM4_LINES]);

Include Files

crypto_mb/sm4.h

Parameters

pa_out	Array of pointers up to 16 output data streams.
pa_in	Array of pointers up to 16 input data streams.
len	Array of lengths of the input data in bytes for up to 16 buffers.
key_sched1	Array of scheduled keys (from first 16 bytes of key) for up to 16 buffers.
key_sched2	Array of scheduled keys (from second 16 bytes of key) for up to 16 buffers.
pa_tweak	Array of pointers to the 16-byte tweaks (similar to IV) for up to 16 buffers.

Description

These functions encrypt/decrypt the input data streams passed by pa_in of a variable length (up to 2^32 -1 bytes) passed through len array according to the XTS cipher scheme and store the results into the memory buffers specified in pa_out parameter.

Return Values

The mbx_sm4_set_key_mb16() function returns the status that indicates whether the operation completed successfully or not. The status value of 0 indicates that the key schedule was successfully initialized. In case of non-zero status value, MBX_GET_HIGH_PART_STS16() and MBX_GET_LOW_PART_STS16() can help to get the low and high parts of the mbx_status16, which can be analyzed separately with MBX_GET_STS() call. The low part includes first eight statuses, while the high part includes remaining eight statuses for each operation.