Request
| Index Word | Description |
|---|---|
| 0 | Header code [0x00470104] |
| 1 | Output buffer size |
| 2 | Input buffer size |
| 3 | Block size |
| 4 | Nonce size, size 12 is used if this is >12. |
| 5 | (inputbufsize<<4) | 10 |
| 6 | Input encrypted data buffer ptr |
| 7 | (outputbufsize<<4) | 12 |
| 8 | Output cleartext data buffer ptr |
Response
| Index Word | Description |
|---|---|
| 0 | Header code |
| 1 | Result code |
Description
This decrypts the input data with AES-CCM using keytype2, when the input noncesize is <12 the low 2-bits are cleared in the noncesize. The 12-byte nonce buffer used by NS is cleared to all-zero, then the nonce from inputbuf+0 with the noncesize is copied to this nonce buffer. NS then uses PS:EncryptSignDecryptVerifyAesCcm with keytype2 and with the above nonce buffer, where the inputptr is inputbuf+noncesize, outputptr is outputbuf+0, and size is inputbuffersize - noncesize - 16.
After decryption, NS copies the data at outbuf+blocksize to outbuf+blocksize+noncesize, with size inputbuffersize-blocksize-16. NS then copies the nonce from inputbuf+0 with the noncesize, to outbuf+blocksize.