Message digests
Description
Functions |
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psa_status_t | psa_hash_compute ( psa_algorithm_t alg, const uint8_t *input, size_t input_length, uint8_t *hash, size_t hash_size, size_t *hash_length) |
Calculate the hash (digest) of a message.
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psa_status_t | psa_hash_compare ( psa_algorithm_t alg, const uint8_t *input, size_t input_length, const uint8_t *hash, size_t hash_length) |
Calculate the hash (digest) of a message and compare it with a reference value.
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psa_status_t | psa_hash_setup (psa_hash_operation_t *operation, psa_algorithm_t alg) |
Set up a multipart hash operation.
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psa_status_t | psa_hash_update (psa_hash_operation_t *operation, const uint8_t *input, size_t input_length) |
Add a message fragment to a multipart hash operation.
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psa_status_t | psa_hash_finish (psa_hash_operation_t *operation, uint8_t *hash, size_t hash_size, size_t *hash_length) |
Finish the calculation of the hash of a message.
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psa_status_t | psa_hash_verify (psa_hash_operation_t *operation, const uint8_t *hash, size_t hash_length) |
Finish the calculation of the hash of a message and compare it with an expected value.
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psa_status_t | psa_hash_abort (psa_hash_operation_t *operation) |
Abort a hash operation.
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psa_status_t | psa_hash_clone (const psa_hash_operation_t *source_operation, psa_hash_operation_t *target_operation) |
Clone a hash operation.
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Macros |
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#define | PSA_HASH_OPERATION_INIT { 0, { 0 } } |
Function Documentation
◆ psa_hash_compute()
psa_status_t psa_hash_compute | ( | psa_algorithm_t |
alg,
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const uint8_t * |
input,
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size_t |
input_length,
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uint8_t * |
hash,
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size_t |
hash_size,
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size_t * |
hash_length
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) |
Calculate the hash (digest) of a message.
- Note
- To verify the hash of a message against an expected value, use psa_hash_compare() instead.
- Parameters
-
alg
The hash algorithm to compute ( PSA_ALG_XXX
value such that PSA_ALG_IS_HASH (alg
) is true).[in] input
Buffer containing the message to hash. input_length
Size of the input
buffer in bytes.[out] hash
Buffer where the hash is to be written. hash_size
Size of the hash
buffer in bytes.[out] hash_length
On success, the number of bytes that make up the hash value. This is always #PSA_HASH_LENGTH( alg
).
- Return values
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PSA_SUCCESS
Success. PSA_ERROR_NOT_SUPPORTED
alg
is not supported or is not a hash algorithm.PSA_ERROR_INVALID_ARGUMENT
PSA_ERROR_BUFFER_TOO_SMALL
hash_size
is too smallPSA_ERROR_INSUFFICIENT_MEMORY
PSA_ERROR_COMMUNICATION_FAILURE
PSA_ERROR_HARDWARE_FAILURE
PSA_ERROR_CORRUPTION_DETECTED
PSA_ERROR_BAD_STATE
The library has not been previously initialized by psa_crypto_init() . It is implementation-dependent whether a failure to initialize results in this error code.
◆ psa_hash_compare()
psa_status_t psa_hash_compare | ( | psa_algorithm_t |
alg,
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const uint8_t * |
input,
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size_t |
input_length,
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const uint8_t * |
hash,
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size_t |
hash_length
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) |
Calculate the hash (digest) of a message and compare it with a reference value.
- Parameters
-
alg
The hash algorithm to compute ( PSA_ALG_XXX
value such that PSA_ALG_IS_HASH (alg
) is true).[in] input
Buffer containing the message to hash. input_length
Size of the input
buffer in bytes.[out] hash
Buffer containing the expected hash value. hash_length
Size of the hash
buffer in bytes.
- Return values
-
PSA_SUCCESS
The expected hash is identical to the actual hash of the input. PSA_ERROR_INVALID_SIGNATURE
The hash of the message was calculated successfully, but it differs from the expected hash. PSA_ERROR_NOT_SUPPORTED
alg
is not supported or is not a hash algorithm.PSA_ERROR_INVALID_ARGUMENT
input_length
orhash_length
do not match the hash size foralg
PSA_ERROR_INSUFFICIENT_MEMORY
PSA_ERROR_COMMUNICATION_FAILURE
PSA_ERROR_HARDWARE_FAILURE
PSA_ERROR_CORRUPTION_DETECTED
PSA_ERROR_BAD_STATE
The library has not been previously initialized by psa_crypto_init() . It is implementation-dependent whether a failure to initialize results in this error code.
◆ psa_hash_setup()
psa_status_t psa_hash_setup | ( | psa_hash_operation_t * |
operation,
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psa_algorithm_t |
alg
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Set up a multipart hash operation.
The sequence of operations to calculate a hash (message digest) is as follows:
- Allocate an operation object which will be passed to all the functions listed here.
- Initialize the operation object with one of the methods described in the documentation for #psa_hash_operation_t, e.g. PSA_HASH_OPERATION_INIT .
- Call psa_hash_setup() to specify the algorithm.
- Call psa_hash_update() zero, one or more times, passing a fragment of the message each time. The hash that is calculated is the hash of the concatenation of these messages in order.
- To calculate the hash, call psa_hash_finish() . To compare the hash with an expected value, call psa_hash_verify() .
If an error occurs at any step after a call to psa_hash_setup() , the operation will need to be reset by a call to psa_hash_abort() . The application may call psa_hash_abort() at any time after the operation has been initialized.
After a successful call to psa_hash_setup() , the application must eventually terminate the operation. The following events terminate an operation:
- A successful call to psa_hash_finish() or psa_hash_verify() .
- A call to psa_hash_abort() .
- Parameters
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[in,out] operation
The operation object to set up. It must have been initialized as per the documentation for #psa_hash_operation_t and not yet in use. alg
The hash algorithm to compute ( PSA_ALG_XXX
value such that PSA_ALG_IS_HASH (alg
) is true).
- Return values
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PSA_SUCCESS
Success. PSA_ERROR_NOT_SUPPORTED
alg
is not a supported hash algorithm.PSA_ERROR_INVALID_ARGUMENT
alg
is not a hash algorithm.PSA_ERROR_INSUFFICIENT_MEMORY
PSA_ERROR_COMMUNICATION_FAILURE
PSA_ERROR_HARDWARE_FAILURE
PSA_ERROR_CORRUPTION_DETECTED
PSA_ERROR_BAD_STATE
The operation state is not valid (it must be inactive), or the library has not been previously initialized by psa_crypto_init() . It is implementation-dependent whether a failure to initialize results in this error code.
◆ psa_hash_update()
psa_status_t psa_hash_update | ( | psa_hash_operation_t * |
operation,
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const uint8_t * |
input,
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size_t |
input_length
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) |
Add a message fragment to a multipart hash operation.
The application must call psa_hash_setup() before calling this function.
If this function returns an error status, the operation enters an error state and must be aborted by calling psa_hash_abort() .
- Parameters
-
[in,out] operation
Active hash operation. [in] input
Buffer containing the message fragment to hash. input_length
Size of the input
buffer in bytes.
- Return values
-
PSA_SUCCESS
Success. PSA_ERROR_INSUFFICIENT_MEMORY
PSA_ERROR_COMMUNICATION_FAILURE
PSA_ERROR_HARDWARE_FAILURE
PSA_ERROR_CORRUPTION_DETECTED
PSA_ERROR_BAD_STATE
The operation state is not valid (it must be active), or the library has not been previously initialized by psa_crypto_init() . It is implementation-dependent whether a failure to initialize results in this error code.
◆ psa_hash_finish()
psa_status_t psa_hash_finish | ( | psa_hash_operation_t * |
operation,
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uint8_t * |
hash,
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size_t |
hash_size,
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size_t * |
hash_length
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) |
Finish the calculation of the hash of a message.
The application must call psa_hash_setup() before calling this function. This function calculates the hash of the message formed by concatenating the inputs passed to preceding calls to psa_hash_update() .
When this function returns successfully, the operation becomes inactive. If this function returns an error status, the operation enters an error state and must be aborted by calling psa_hash_abort() .
- Warning
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Applications should not call this function if they expect a specific value for the hash. Call
psa_hash_verify()
instead. Beware that comparing integrity or authenticity data such as hash values with a function such as
memcmp
is risky because the time taken by the comparison may leak information about the hashed data which could allow an attacker to guess a valid hash and thereby bypass security controls.
- Parameters
-
[in,out] operation
Active hash operation. [out] hash
Buffer where the hash is to be written. hash_size
Size of the hash
buffer in bytes.[out] hash_length
On success, the number of bytes that make up the hash value. This is always #PSA_HASH_LENGTH( alg
) wherealg
is the hash algorithm that is calculated.
- Return values
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PSA_SUCCESS
Success. PSA_ERROR_BUFFER_TOO_SMALL
The size of the hash
buffer is too small. You can determine a sufficient buffer size by calling #PSA_HASH_LENGTH(alg
) wherealg
is the hash algorithm that is calculated.PSA_ERROR_INSUFFICIENT_MEMORY
PSA_ERROR_COMMUNICATION_FAILURE
PSA_ERROR_HARDWARE_FAILURE
PSA_ERROR_CORRUPTION_DETECTED
PSA_ERROR_BAD_STATE
The operation state is not valid (it must be active), or the library has not been previously initialized by psa_crypto_init() . It is implementation-dependent whether a failure to initialize results in this error code.
◆ psa_hash_verify()
psa_status_t psa_hash_verify | ( | psa_hash_operation_t * |
operation,
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const uint8_t * |
hash,
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size_t |
hash_length
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) |
Finish the calculation of the hash of a message and compare it with an expected value.
The application must call psa_hash_setup() before calling this function. This function calculates the hash of the message formed by concatenating the inputs passed to preceding calls to psa_hash_update() . It then compares the calculated hash with the expected hash passed as a parameter to this function.
When this function returns successfully, the operation becomes inactive. If this function returns an error status, the operation enters an error state and must be aborted by calling psa_hash_abort() .
- Note
- Implementations shall make the best effort to ensure that the comparison between the actual hash and the expected hash is performed in constant time.
- Parameters
-
[in,out] operation
Active hash operation. [in] hash
Buffer containing the expected hash value. hash_length
Size of the hash
buffer in bytes.
- Return values
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PSA_SUCCESS
The expected hash is identical to the actual hash of the message. PSA_ERROR_INVALID_SIGNATURE
The hash of the message was calculated successfully, but it differs from the expected hash. PSA_ERROR_INSUFFICIENT_MEMORY
PSA_ERROR_COMMUNICATION_FAILURE
PSA_ERROR_HARDWARE_FAILURE
PSA_ERROR_CORRUPTION_DETECTED
PSA_ERROR_BAD_STATE
The operation state is not valid (it must be active), or the library has not been previously initialized by psa_crypto_init() . It is implementation-dependent whether a failure to initialize results in this error code.
◆ psa_hash_abort()
psa_status_t psa_hash_abort | ( | psa_hash_operation_t * |
operation
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Abort a hash operation.
Aborting an operation frees all associated resources except for the
operation
structure itself. Once aborted, the operation object can be reused for another operation by calling
psa_hash_setup()
again.
You may call this function any time after the operation object has been initialized by one of the methods described in #psa_hash_operation_t.
In particular, calling psa_hash_abort() after the operation has been terminated by a call to psa_hash_abort() , psa_hash_finish() or psa_hash_verify() is safe and has no effect.
- Parameters
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[in,out] operation
Initialized hash operation.
- Return values
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PSA_SUCCESS
PSA_ERROR_COMMUNICATION_FAILURE
PSA_ERROR_HARDWARE_FAILURE
PSA_ERROR_CORRUPTION_DETECTED
PSA_ERROR_BAD_STATE
The library has not been previously initialized by psa_crypto_init() . It is implementation-dependent whether a failure to initialize results in this error code.
◆ psa_hash_clone()
psa_status_t psa_hash_clone | ( | const psa_hash_operation_t * |
source_operation,
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psa_hash_operation_t * |
target_operation
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) |
Clone a hash operation.
This function copies the state of an ongoing hash operation to a new operation object. In other words, this function is equivalent to calling
psa_hash_setup()
on
target_operation
with the same algorithm that
source_operation
was set up for, then
psa_hash_update()
on
target_operation
with the same input that that was passed to
source_operation
. After this function returns, the two objects are independent, i.e. subsequent calls involving one of the objects do not affect the other object.
- Parameters
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[in] source_operation
The active hash operation to clone. [in,out] target_operation
The operation object to set up. It must be initialized but not active.
- Return values
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PSA_SUCCESS
PSA_ERROR_COMMUNICATION_FAILURE
PSA_ERROR_HARDWARE_FAILURE
PSA_ERROR_CORRUPTION_DETECTED
PSA_ERROR_INSUFFICIENT_MEMORY
PSA_ERROR_BAD_STATE
The source_operation
state is not valid (it must be active), or thetarget_operation
state is not valid (it must be inactive), or the library has not been previously initialized by psa_crypto_init() . It is implementation-dependent whether a failure to initialize results in this error code.
Macro Definition Documentation
◆ PSA_HASH_OPERATION_INIT
#define PSA_HASH_OPERATION_INIT { 0, { 0 } } |
This macro returns a suitable initializer for a hash operation object of type #psa_hash_operation_t.