poly1305.h
Functions
Name | |
---|---|
int | wc_Poly1305SetKey(Poly1305 * poly1305, const byte * key, word32 kySz) This function sets the key for a Poly1305 context structure, initializing it for hashing. Note: A new key should be set after generating a message hash with wc_Poly1305Final to ensure security. |
int | wc_Poly1305Update(Poly1305 * poly1305, const byte * m, word32 bytes) This function updates the message to hash with the Poly1305 structure. |
int | wc_Poly1305Final(Poly1305 * poly1305, byte * tag) This function calculates the hash of the input messages and stores the result in mac. After this is called, the key should be reset. |
int | wc_Poly1305_MAC(Poly1305 * ctx, byte * additional, word32 addSz, byte * input, word32 sz, byte * tag, word32 tagSz) Takes in an initialized Poly1305 struct that has a key loaded and creates a MAC (tag) using recent TLS AEAD padding scheme. |
Functions Documentation
function wc_Poly1305SetKey
int wc_Poly1305SetKey(
Poly1305 * poly1305,
const byte * key,
word32 kySz
)
This function sets the key for a Poly1305 context structure, initializing it for hashing. Note: A new key should be set after generating a message hash with wc_Poly1305Final to ensure security.
Parameters:
- ctx pointer to a Poly1305 structure to initialize
- key pointer to the buffer containing the key to use for hashing
- keySz size of the key in the buffer. Should be 32 bytes
See:
Return:
- 0 Returned on successfully setting the key and initializing the Poly1305 structure
- BAD_FUNC_ARG Returned if the given key is not 32 bytes long, or the Poly1305 context is NULL
Example
Poly1305 enc;
byte key[] = { initialize with 32 byte key to use for hashing };
wc_Poly1305SetKey(&enc, key, sizeof(key));
function wc_Poly1305Update
int wc_Poly1305Update(
Poly1305 * poly1305,
const byte * m,
word32 bytes
)
This function updates the message to hash with the Poly1305 structure.
Parameters:
- ctx pointer to a Poly1305 structure for which to update the message to hash
- m pointer to the buffer containing the message which should be added to the hash
- bytes size of the message to hash
See:
Return:
- 0 Returned on successfully updating the message to hash
- BAD_FUNC_ARG Returned if the Poly1305 structure is NULL
Example
Poly1305 enc;
byte key[] = { }; // initialize with 32 byte key to use for encryption
byte msg[] = { }; // initialize with message to hash
wc_Poly1305SetKey(&enc, key, sizeof(key));
if( wc_Poly1305Update(key, msg, sizeof(msg)) != 0 ) {
// error updating message to hash
}
function wc_Poly1305Final
int wc_Poly1305Final(
Poly1305 * poly1305,
byte * tag
)
This function calculates the hash of the input messages and stores the result in mac. After this is called, the key should be reset.
Parameters:
- ctx pointer to a Poly1305 structure with which to generate the MAC
- mac pointer to the buffer in which to store the MAC. Should be POLY1305_DIGEST_SIZE (16 bytes) wide
See:
Return:
- 0 Returned on successfully computing the final MAC
- BAD_FUNC_ARG Returned if the Poly1305 structure is NULL
Example
Poly1305 enc;
byte mac[POLY1305_DIGEST_SIZE]; // space for a 16 byte mac
byte key[] = { }; // initialize with 32 byte key to use for encryption
byte msg[] = { }; // initialize with message to hash
wc_Poly1305SetKey(&enc, key, sizeof(key));
wc_Poly1305Update(key, msg, sizeof(msg));
if ( wc_Poly1305Final(&enc, mac) != 0 ) {
// error computing final MAC
}
function wc_Poly1305_MAC
int wc_Poly1305_MAC(
Poly1305 * ctx,
byte * additional,
word32 addSz,
byte * input,
word32 sz,
byte * tag,
word32 tagSz
)
Takes in an initialized Poly1305 struct that has a key loaded and creates a MAC (tag) using recent TLS AEAD padding scheme.
Parameters:
- ctx Initialized Poly1305 struct to use
- additional Additional data to use
- addSz Size of additional buffer
- input Input buffer to create tag from
- sz Size of input buffer
- tag Buffer to hold created tag
- tagSz Size of input tag buffer (must be at least WC_POLY1305_MAC_SZ(16))
See:
- wc_Poly1305SetKey
- wc_Poly1305Update
- wcPoly1305Final
Return:
- 0 Success
- BAD_FUNC_ARG Returned if ctx, input, or tag is null or if additional is null and addSz is greater than 0 or if tagSz is less than WC_POLY1305_MAC_SZ.
Example
Poly1305 ctx;
byte key[] = { }; // initialize with 32 byte key to use for hashing
byte additional[] = { }; // initialize with additional data
byte msg[] = { }; // initialize with message
byte tag[16];
wc_Poly1305SetKey(&ctx, key, sizeof(key));
if(wc_Poly1305_MAC(&ctx, additional, sizeof(additional), (byte*)msg,
sizeof(msg), tag, sizeof(tag)) != 0)
{
// Handle the error
}
Source code
int wc_Poly1305SetKey(Poly1305* poly1305, const byte* key,
word32 kySz);
int wc_Poly1305Update(Poly1305* poly1305, const byte* m, word32 bytes);
int wc_Poly1305Final(Poly1305* poly1305, byte* tag);
int wc_Poly1305_MAC(Poly1305* ctx, byte* additional, word32 addSz,
byte* input, word32 sz, byte* tag, word32 tagSz);
Updated on 2024-12-06 at 01:17:08 +0000