This file provides firmware functions to manage the following functionalities of the Cryptographic processor (CRYP) peripheral: More...
Include dependency graph for stm32f4xx_cryp.c:
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Macros | |
| #define | FLAG_MASK ((uint8_t)0x20) |
| #define | MAX_TIMEOUT ((uint16_t)0xFFFF) |
Functions | |
| void | CRYP_Cmd (FunctionalState NewState) |
| Enables or disables the CRYP peripheral. More... | |
| void | CRYP_DataIn (uint32_t Data) |
| Writes data in the Data Input register (DIN). More... | |
| uint32_t | CRYP_DataOut (void) |
| Returns the last data entered into the output FIFO. More... | |
| void | CRYP_DeInit (void) |
| Deinitializes the CRYP peripheral registers to their default reset values. More... | |
| void | CRYP_DMACmd (uint8_t CRYP_DMAReq, FunctionalState NewState) |
| Enables or disables the CRYP DMA interface. More... | |
| void | CRYP_FIFOFlush (void) |
| Flushes the IN and OUT FIFOs (that is read and write pointers of the FIFOs are reset) More... | |
| FunctionalState | CRYP_GetCmdStatus (void) |
| Returns whether CRYP peripheral is enabled or disabled. More... | |
| FlagStatus | CRYP_GetFlagStatus (uint8_t CRYP_FLAG) |
| Checks whether the specified CRYP flag is set or not. More... | |
| ITStatus | CRYP_GetITStatus (uint8_t CRYP_IT) |
| Checks whether the specified CRYP interrupt has occurred or not. More... | |
| void | CRYP_Init (CRYP_InitTypeDef *CRYP_InitStruct) |
| Initializes the CRYP peripheral according to the specified parameters in the CRYP_InitStruct. More... | |
| void | CRYP_ITConfig (uint8_t CRYP_IT, FunctionalState NewState) |
| Enables or disables the specified CRYP interrupts. More... | |
| void | CRYP_IVInit (CRYP_IVInitTypeDef *CRYP_IVInitStruct) |
| Initializes the CRYP Initialization Vectors(IV) according to the specified parameters in the CRYP_IVInitStruct. More... | |
| void | CRYP_IVStructInit (CRYP_IVInitTypeDef *CRYP_IVInitStruct) |
| Fills each CRYP_IVInitStruct member with its default value. More... | |
| void | CRYP_KeyInit (CRYP_KeyInitTypeDef *CRYP_KeyInitStruct) |
| Initializes the CRYP Keys according to the specified parameters in the CRYP_KeyInitStruct. More... | |
| void | CRYP_KeyStructInit (CRYP_KeyInitTypeDef *CRYP_KeyInitStruct) |
| Fills each CRYP_KeyInitStruct member with its default value. More... | |
| void | CRYP_PhaseConfig (uint32_t CRYP_Phase) |
| Configures the AES-CCM and AES-GCM phases. More... | |
| void | CRYP_RestoreContext (CRYP_Context *CRYP_ContextRestore) |
| Restores the CRYP peripheral Context. More... | |
| ErrorStatus | CRYP_SaveContext (CRYP_Context *CRYP_ContextSave, CRYP_KeyInitTypeDef *CRYP_KeyInitStruct) |
| Saves the CRYP peripheral Context. More... | |
| void | CRYP_StructInit (CRYP_InitTypeDef *CRYP_InitStruct) |
| Fills each CRYP_InitStruct member with its default value. More... | |
Detailed Description
This file provides firmware functions to manage the following functionalities of the Cryptographic processor (CRYP) peripheral:
- Version
- V1.1.0
- Date
- 11-January-2013
- Initialization and Configuration functions
- Data treatment functions
- Context swapping functions
- DMA interface function
- Interrupts and flags management
===================================================================
##### How to use this driver #####
===================================================================
[..]
(#) Enable the CRYP controller clock using
RCC_AHB2PeriphClockCmd(RCC_AHB2Periph_CRYP, ENABLE); function.
(#) Initialise the CRYP using CRYP_Init(), CRYP_KeyInit() and if needed
CRYP_IVInit().
(#) Flush the IN and OUT FIFOs by using CRYP_FIFOFlush() function.
(#) Enable the CRYP controller using the CRYP_Cmd() function.
(#) If using DMA for Data input and output transfer, activate the needed DMA
Requests using CRYP_DMACmd() function
(#) If DMA is not used for data transfer, use CRYP_DataIn() and CRYP_DataOut()
functions to enter data to IN FIFO and get result from OUT FIFO.
(#) To control CRYP events you can use one of the following two methods:
(++) Check on CRYP flags using the CRYP_GetFlagStatus() function.
(++) Use CRYP interrupts through the function CRYP_ITConfig() at
initialization phase and CRYP_GetITStatus() function into interrupt
routines in processing phase.
(#) Save and restore Cryptographic processor context using CRYP_SaveContext()
and CRYP_RestoreContext() functions.
*** Procedure to perform an encryption or a decryption ***
==========================================================
*** Initialization ***
======================
[..]
(#) Initialize the peripheral using CRYP_Init(), CRYP_KeyInit() and CRYP_IVInit
functions:
(++) Configure the key size (128-, 192- or 256-bit, in the AES only)
(++) Enter the symmetric key
(++) Configure the data type
(++) In case of decryption in AES-ECB or AES-CBC, you must prepare
the key: configure the key preparation mode. Then Enable the CRYP
peripheral using CRYP_Cmd() function: the BUSY flag is set.
Wait until BUSY flag is reset : the key is prepared for decryption
(++) Configure the algorithm and chaining (the DES/TDES in ECB/CBC, the
AES in ECB/CBC/CTR)
(++) Configure the direction (encryption/decryption).
(++) Write the initialization vectors (in CBC or CTR modes only)
(#) Flush the IN and OUT FIFOs using the CRYP_FIFOFlush() function
*** Basic Processing mode (polling mode) ***
============================================
[..]
(#) Enable the cryptographic processor using CRYP_Cmd() function.
(#) Write the first blocks in the input FIFO (2 to 8 words) using
CRYP_DataIn() function.
(#) Repeat the following sequence until the complete message has been
processed:
(++) Wait for flag CRYP_FLAG_OFNE occurs (using CRYP_GetFlagStatus()
function), then read the OUT-FIFO using CRYP_DataOut() function
(1 block or until the FIFO is empty)
(++) Wait for flag CRYP_FLAG_IFNF occurs, (using CRYP_GetFlagStatus()
function then write the IN FIFO using CRYP_DataIn() function
(1 block or until the FIFO is full)
(#) At the end of the processing, CRYP_FLAG_BUSY flag will be reset and
both FIFOs are empty (CRYP_FLAG_IFEM is set and CRYP_FLAG_OFNE is
reset). You can disable the peripheral using CRYP_Cmd() function.
*** Interrupts Processing mode ***
==================================
[..] In this mode, Processing is done when the data are transferred by the
CPU during interrupts.
(#) Enable the interrupts CRYP_IT_INI and CRYP_IT_OUTI using CRYP_ITConfig()
function.
(#) Enable the cryptographic processor using CRYP_Cmd() function.
(#) In the CRYP_IT_INI interrupt handler : load the input message into the
IN FIFO using CRYP_DataIn() function . You can load 2 or 4 words at a
time, or load data until the IN FIFO is full. When the last word of
the message has been entered into the IN FIFO, disable the CRYP_IT_INI
interrupt (using CRYP_ITConfig() function).
(#) In the CRYP_IT_OUTI interrupt handler : read the output message from
the OUT FIFO using CRYP_DataOut() function. You can read 1 block (2 or
4 words) at a time or read data until the FIFO is empty.
When the last word has been read, INIM=0, BUSY=0 and both FIFOs are
empty (CRYP_FLAG_IFEM is set and CRYP_FLAG_OFNE is reset).
You can disable the CRYP_IT_OUTI interrupt (using CRYP_ITConfig()
function) and you can disable the peripheral using CRYP_Cmd() function.
*** DMA Processing mode ***
===========================
[..] In this mode, Processing is done when the DMA is used to transfer the
data from/to the memory.
(#) Configure the DMA controller to transfer the input data from the
memory using DMA_Init() function.
The transfer length is the length of the message.
As message padding is not managed by the peripheral, the message
length must be an entire number of blocks. The data are transferred
in burst mode. The burst length is 4 words in the AES and 2 or 4
words in the DES/TDES. The DMA should be configured to set an
interrupt on transfer completion of the output data to indicate that
the processing is finished.
Refer to DMA peripheral driver for more details.
(#) Enable the cryptographic processor using CRYP_Cmd() function.
Enable the DMA requests CRYP_DMAReq_DataIN and CRYP_DMAReq_DataOUT
using CRYP_DMACmd() function.
(#) All the transfers and processing are managed by the DMA and the
cryptographic processor. The DMA transfer complete interrupt indicates
that the processing is complete. Both FIFOs are normally empty and
CRYP_FLAG_BUSY flag is reset.@attention
<h2><center>© COPYRIGHT 2013 STMicroelectronics</center></h2>
Licensed under MCD-ST Liberty SW License Agreement V2, (the "License");
You may not use this file except in compliance with the License.
You may obtain a copy of the License at:
http://www.st.com/software_license_agreement_liberty_v2
Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
Definition in file stm32f4xx_cryp.c.