Use case: encryption/decryption in DMA mode

Sequence diagram

Encryption/decryption in DMA mode

@startuml participant "Application" as App participant "CRYP" as CRYP note over App,CRYP: Encryption App -> CRYP: HAL_CRYP_Encrypt_DMA() group opt note over App,CRYP: Tag generation App -> CRYP: HAL_CRYPEx_AESGCM_GenerateAuthTAG() note right: **Only for GCM algorithm** App -> CRYP: HAL_CRYPEx_AESCCM_GenerateAuthTAG() note right: **Only for CCM algorithm** end group note over App,CRYP: Decryption App -> CRYP: HAL_CRYP_Decrypt_DMA() group opt note over App,CRYP: Tag generation App -> CRYP: HAL_CRYPEx_AESGCM_GenerateAuthTAG() note right: **Only for GCM algorithm** App -> CRYP: HAL_CRYPEx_AESCCM_GenerateAuthTAG() note right: **Only for CCM algorithm** end group @enduml

Code snippet

HAL1

HAL2 

/* Encryption */
HAL_CRYP_Encrypt_DMA(&hcryp, Plaintext, PLAINTEXT_SIZE,
                         EncryptedText);

/* Only for GCM algorithm */
HAL_CRYPEx_AESGCM_GenerateAuthTAG(&hcryp,TAG,
                                        TIMEOUT_VALUE);

/* Only for CCM algorithm */
HAL_CRYPEx_AESCCM_GenerateAuthTAG(&hcryp,TAG,
                                        TIMEOUT_VALUE);

/* Decryption */
HAL_CRYP_Decrypt_DMA(&hcryp,Ciphertext , PLAINTEXT_SIZE,
                         DecryptedText);

/* Only for GCM algorithm */
HAL_CRYPEx_AESGCM_GenerateAuthTAG(&hcryp,TAG,
                                        TIMEOUT_VALUE);

/* Only for CCM algorithm */
HAL_CRYPEx_AESCCM_GenerateAuthTAG(&hcryp,TAG,
                                        TIMEOUT_VALUE);

/* Encryption */
HAL_CRYP_Encrypt_DMA(&hcryp, Plaintext, PLAINTEXT_SIZE ,
                                       EncryptedText);

/* Only for GCM algorithm */
HAL_CRYP_GCM_GenerateAuthTAG(&hcryp,TAG,
                                      TIMEOUT_VALUE);

/* Only for CCM algorithm */
HAL_CRYP_CCM_GenerateAuthTAG(&hcryp,TAG,
                                     TIMEOUT_VALUE);

/* Decryption */
HAL_CRYP_Decrypt_DMA(&hcryp, Ciphertext, PLAINTEXT_SIZE ,
                                        DecryptedText);

/* Only for GCM algorithm */
HAL_CRYP_GCM_GenerateAuthTAG(&hcryp,TAG,
                                      TIMEOUT_VALUE);

/* Only for CCM algorithm */
HAL_CRYP_CCM_GenerateAuthTAG(&hcryp,TAG,
                                     TIMEOUT_VALUE);

Key changes

  1. DMA-mode encryption and decryption APIs keep the same names (HAL_CRYP_Encrypt_DMA() / HAL_CRYP_Decrypt_DMA()).

  2. Tag generation APIs are renamed from HAL_CRYPEx_AES* to HAL_CRYP_* for GCM and CCM algorithms.