File sha256.h
This file contains SHA-224 and SHA-256 definitions and functions.
The Secure Hash Algorithms 224 and 256 (SHA-224 and SHA-256) cryptographic hash functions are defined in FIPS 180-4: Secure Hash Standard (SHS).
Defines
-
MBEDTLS_ERR_SHA256_BAD_INPUT_DATA
SHA-256 input data was malformed.
Typedefs
-
typedef struct mbedtls_sha256_context mbedtls_sha256_context
The SHA-256 context structure.
The structure is used both for SHA-256 and for SHA-224 checksum calculations. The choice between these two is made in the call to mbedtls_sha256_starts().
Functions
-
void mbedtls_sha256_init(mbedtls_sha256_context *ctx)
This function initializes a SHA-256 context.
- Parameters:
ctx – The SHA-256 context to initialize. This must not be
NULL
.
-
void mbedtls_sha256_free(mbedtls_sha256_context *ctx)
This function clears a SHA-256 context.
- Parameters:
ctx – The SHA-256 context to clear. This may be
NULL
, in which case this function returns immediately. If it is notNULL
, it must point to an initialized SHA-256 context.
-
void mbedtls_sha256_clone(mbedtls_sha256_context *dst, const mbedtls_sha256_context *src)
This function clones the state of a SHA-256 context.
- Parameters:
dst – The destination context. This must be initialized.
src – The context to clone. This must be initialized.
-
int mbedtls_sha256_starts(mbedtls_sha256_context *ctx, int is224)
This function starts a SHA-224 or SHA-256 checksum calculation.
Note
is224 must be defined accordingly to the enabled MBEDTLS_SHA224_C/MBEDTLS_SHA256_C symbols otherwise the function will return MBEDTLS_ERR_SHA512_BAD_INPUT_DATA.
- Parameters:
ctx – The context to use. This must be initialized.
is224 – This determines which function to use. This must be either
0
for SHA-256, or1
for SHA-224.
- Returns:
0
on success.- Returns:
A negative error code on failure.
-
int mbedtls_sha256_update(mbedtls_sha256_context *ctx, const unsigned char *input, size_t ilen)
This function feeds an input buffer into an ongoing SHA-256 checksum calculation.
- Parameters:
ctx – The SHA-256 context. This must be initialized and have a hash operation started.
input – The buffer holding the data. This must be a readable buffer of length
ilen
Bytes.ilen – The length of the input data in Bytes.
- Returns:
0
on success.- Returns:
A negative error code on failure.
-
int mbedtls_sha256_finish(mbedtls_sha256_context *ctx, unsigned char *output)
This function finishes the SHA-256 operation, and writes the result to the output buffer.
- Parameters:
ctx – The SHA-256 context. This must be initialized and have a hash operation started.
output – The SHA-224 or SHA-256 checksum result. This must be a writable buffer of length
32
bytes for SHA-256,28
bytes for SHA-224.
- Returns:
0
on success.- Returns:
A negative error code on failure.
-
int mbedtls_sha256(const unsigned char *input, size_t ilen, unsigned char *output, int is224)
This function calculates the SHA-224 or SHA-256 checksum of a buffer.
The function allocates the context, performs the calculation, and frees the context.
The SHA-256 result is calculated as output = SHA-256(input buffer).
- Parameters:
input – The buffer holding the data. This must be a readable buffer of length
ilen
Bytes.ilen – The length of the input data in Bytes.
output – The SHA-224 or SHA-256 checksum result. This must be a writable buffer of length
32
bytes for SHA-256,28
bytes for SHA-224.is224 – Determines which function to use. This must be either
0
for SHA-256, or1
for SHA-224.
- Returns:
0
on success.- Returns:
A negative error code on failure.
-
int mbedtls_sha224_self_test(int verbose)
The SHA-224 checkup routine.
- Returns:
0
on success.- Returns:
1
on failure.
-
int mbedtls_sha256_self_test(int verbose)
The SHA-256 checkup routine.
- Returns:
0
on success.- Returns:
1
on failure.
-
struct mbedtls_sha256_context
- #include <sha256.h>
The SHA-256 context structure.
The structure is used both for SHA-256 and for SHA-224 checksum calculations. The choice between these two is made in the call to mbedtls_sha256_starts().