mbx_sm4_gcm_encrypt/decrypt_mb16

Processes additional authenticated data (AAD).

Syntax

mbx_status16 mbx_sm4_gcm_encrypt_mb16(int8u* pa_out[SM4_LINES], const int8u* pa_in[SM4_LINES], const int in_len[SM4_LINES], SM4_GCM_CTX_mb16* p_context);

mbx_status16 mbx_sm4_gcm_decrypt_mb16(int8u* pa_out[SM4_LINES], const int8u* pa_in[SM4_LINES], const int in_len[SM4_LINES], SM4_GCM_CTX_mb16* p_context);

Include Files

crypto_mb/sm4_gcm.h

Parameters

pa_out	Array of pointers to the output data streams.
pa_in	Array of pointers to the input data streams.
in_len	Array of lengths of the input data in bytes.
p_context	Pointer to the context to keep intermediate results between calls.

Description

These functions encrypt/decrypt the input data streams passed by pa_in of a variable length passed through the in_len array according to the GCM cipher scheme and store the results into the memory buffers specified in the pa_out parameter. The functions also update the context with intermediate hash value.

Note

mbx_sm4_gcm_encrypt_mb16a and mbx_sm4_gcm_decrypt_mb16 have several call sequence restrictions. See SM4 GCM Algorithm Functions page for details.

Note

These functions run the cipher and the authentication as two separate passes over each buffer, so they can read pa_in more than once and read pa_out back. If another party can change these buffers during the call, copy the data to private memory first.

Return Values

The mbx_sm4_gcm_encrypt_mb16/mbx_sm4_gcm_decrypt_mb16() functions return the status that indicates whether the operation is completed successfully or not. The status value of 0 indicates that the key schedule is successfully initialized. In case of a 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 mbx_status16, which can be analyzed separately with the MBX_GET_STS() call. The low part includes the first eight statuses, while the high part includes the remaining eight statuses for each operation.