This file provides firmware functions to manage the following functionalities of the HASH / HMAC Processor (HASH) peripheral: More...
Include dependency graph for stm32f4xx_hash.c:
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Functions | |
| void | HASH_AutoStartDigest (FunctionalState NewState) |
| Enables or disables auto-start message padding and calculation of the final message digest at the end of DMA transfer. More... | |
| void | HASH_ClearFlag (uint32_t HASH_FLAG) |
| Clears the HASH flags. More... | |
| void | HASH_ClearITPendingBit (uint32_t HASH_IT) |
| Clears the HASH interrupt pending bit(s). More... | |
| void | HASH_DataIn (uint32_t Data) |
| Writes data in the Data Input FIFO. More... | |
| void | HASH_DeInit (void) |
| De-initializes the HASH peripheral registers to their default reset values. More... | |
| void | HASH_DMACmd (FunctionalState NewState) |
| Enables or disables the HASH DMA interface. More... | |
| void | HASH_GetDigest (HASH_MsgDigest *HASH_MessageDigest) |
| Provides the message digest result. More... | |
| FlagStatus | HASH_GetFlagStatus (uint32_t HASH_FLAG) |
| Checks whether the specified HASH flag is set or not. More... | |
| uint8_t | HASH_GetInFIFOWordsNbr (void) |
| Returns the number of words already pushed into the IN FIFO. More... | |
| ITStatus | HASH_GetITStatus (uint32_t HASH_IT) |
| Checks whether the specified HASH interrupt has occurred or not. More... | |
| void | HASH_Init (HASH_InitTypeDef *HASH_InitStruct) |
| Initializes the HASH peripheral according to the specified parameters in the HASH_InitStruct structure. More... | |
| void | HASH_ITConfig (uint32_t HASH_IT, FunctionalState NewState) |
| Enables or disables the specified HASH interrupts. More... | |
| void | HASH_Reset (void) |
| Resets the HASH processor core, so that the HASH will be ready to compute the message digest of a new message. More... | |
| void | HASH_RestoreContext (HASH_Context *HASH_ContextRestore) |
| Restore the Hash peripheral Context. More... | |
| void | HASH_SaveContext (HASH_Context *HASH_ContextSave) |
| Save the Hash peripheral Context. More... | |
| void | HASH_SetLastWordValidBitsNbr (uint16_t ValidNumber) |
| Configure the Number of valid bits in last word of the message. More... | |
| void | HASH_StartDigest (void) |
| Starts the message padding and calculation of the final message. More... | |
| void | HASH_StructInit (HASH_InitTypeDef *HASH_InitStruct) |
| Fills each HASH_InitStruct member with its default value. More... | |
Detailed Description
This file provides firmware functions to manage the following functionalities of the HASH / HMAC Processor (HASH) peripheral:
- Version
- V1.1.0
- Date
- 11-January-2013
- Initialization and Configuration functions
- Message Digest generation functions
- context swapping functions
- DMA interface function
- Interrupts and flags management
===================================================================
##### How to use this driver #####
===================================================================
*** HASH operation : ***
========================
[..]
(#) Enable the HASH controller clock using
RCC_AHB2PeriphClockCmd(RCC_AHB2Periph_HASH, ENABLE) function.
(#) Initialise the HASH using HASH_Init() function.
(#) Reset the HASH processor core, so that the HASH will be ready
to compute he message digest of a new message by using HASH_Reset() function.
(#) Enable the HASH controller using the HASH_Cmd() function.
(#) if using DMA for Data input transfer, Activate the DMA Request
using HASH_DMACmd() function
(#) if DMA is not used for data transfer, use HASH_DataIn() function
to enter data to IN FIFO.
(#) Configure the Number of valid bits in last word of the message
using HASH_SetLastWordValidBitsNbr() function.
(#) if the message length is not an exact multiple of 512 bits,
then the function HASH_StartDigest() must be called to launch the computation
of the final digest.
(#) Once computed, the digest can be read using HASH_GetDigest() function.
(#) To control HASH events you can use one of the following wo methods:
(++) Check on HASH flags using the HASH_GetFlagStatus() function.
(++) Use HASH interrupts through the function HASH_ITConfig() at
initialization phase and HASH_GetITStatus() function into
interrupt routines in hashing phase.
After checking on a flag you should clear it using HASH_ClearFlag()
function. And after checking on an interrupt event you should
clear it using HASH_ClearITPendingBit() function.
(#) Save and restore hash processor context using
HASH_SaveContext() and HASH_RestoreContext() functions.
*** HMAC operation : ***
========================
[..] The HMAC algorithm is used for message authentication, by
irreversibly binding the message being processed to a key chosen
by the user.
For HMAC specifications, refer to "HMAC: keyed-hashing for message
authentication, H. Krawczyk, M. Bellare, R. Canetti, February 1997"
[..] Basically, the HMAC algorithm consists of two nested hash operations:
HMAC(message) = Hash[((key | pad) XOR 0x5C) | Hash(((key | pad) XOR 0x36) | message)]
where:
(+) "pad" is a sequence of zeroes needed to extend the key to the
length of the underlying hash function data block (that is
512 bits for both the SHA-1 and MD5 hash algorithms)
(+) "|" represents the concatenation operator
[..]To compute the HMAC, four different phases are required:
(#) Initialise the HASH using HASH_Init() function to do HMAC
operation.
(#) The key (to be used for the inner hash function) is then given to the core.
This operation follows the same mechanism as the one used to send the
message in the hash operation (that is, by HASH_DataIn() function and,
finally, HASH_StartDigest() function.
(#) Once the last word has been entered and computation has started,
the hash processor elaborates the key. It is then ready to accept the message
text using the same mechanism as the one used to send the message in the
hash operation.
(#) After the first hash round, the hash processor returns "ready" to indicate
that it is ready to receive the key to be used for the outer hash function
(normally, this key is the same as the one used for the inner hash function).
When the last word of the key is entered and computation starts, the HMAC
result is made available using HASH_GetDigest() function.@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_hash.c.