Algorithms - ChaCha20_Poly1305
Functions
Name | |
---|---|
int | wc_ChaCha20Poly1305_Encrypt(const byte inKey[CHACHA20_POLY1305_AEAD_KEYSIZE], const byte inIV[CHACHA20_POLY1305_AEAD_IV_SIZE], const byte * inAAD, const word32 inAADLen, const byte * inPlaintext, const word32 inPlaintextLen, byte * outCiphertext, byte outAuthTag[CHACHA20_POLY1305_AEAD_AUTHTAG_SIZE]) This function encrypts an input message, inPlaintext, using the ChaCha20 stream cipher, into the output buffer, outCiphertext. It also performs Poly_1305 authentication (on the cipher text), and stores the generated authentication tag in the output buffer, outAuthTag. |
int | wc_ChaCha20Poly1305_Decrypt(const byte inKey[CHACHA20_POLY1305_AEAD_KEYSIZE], const byte inIV[CHACHA20_POLY1305_AEAD_IV_SIZE], const byte * inAAD, const word32 inAADLen, const byte * inCiphertext, const word32 inCiphertextLen, const byte inAuthTag[CHACHA20_POLY1305_AEAD_AUTHTAG_SIZE], byte * outPlaintext) This function decrypts input ciphertext, inCiphertext, using the ChaCha20 stream cipher, into the output buffer, outPlaintext. It also performs Poly_1305 authentication, comparing the given inAuthTag to an authentication generated with the inAAD (arbitrary length additional authentication data). Note: If the generated authentication tag does not match the supplied authentication tag, the text is not decrypted. |
Functions Documentation
function wc_ChaCha20Poly1305_Encrypt
int wc_ChaCha20Poly1305_Encrypt(
const byte inKey[CHACHA20_POLY1305_AEAD_KEYSIZE],
const byte inIV[CHACHA20_POLY1305_AEAD_IV_SIZE],
const byte * inAAD,
const word32 inAADLen,
const byte * inPlaintext,
const word32 inPlaintextLen,
byte * outCiphertext,
byte outAuthTag[CHACHA20_POLY1305_AEAD_AUTHTAG_SIZE]
)
This function encrypts an input message, inPlaintext, using the ChaCha20 stream cipher, into the output buffer, outCiphertext. It also performs Poly-1305 authentication (on the cipher text), and stores the generated authentication tag in the output buffer, outAuthTag.
Parameters:
- inKey pointer to a buffer containing the 32 byte key to use for encryption
- inIv pointer to a buffer containing the 12 byte iv to use for encryption
- inAAD pointer to the buffer containing arbitrary length additional authenticated data (AAD)
- inAADLen length of the input AAD
- inPlaintext pointer to the buffer containing the plaintext to encrypt
- inPlaintextLen the length of the plain text to encrypt
- outCiphertext pointer to the buffer in which to store the ciphertext
- outAuthTag pointer to a 16 byte wide buffer in which to store the authentication tag
See:
- wc_ChaCha20Poly1305_Decrypt
- wc_ChaCha_*
- wc_Poly1305*
Return:
- 0 Returned upon successfully encrypting the message
- BAD_FUNC_ARG returned if there is an error during the encryption process
Example
byte key[] = { // initialize 32 byte key };
byte iv[] = { // initialize 12 byte key };
byte inAAD[] = { // initialize AAD };
byte plain[] = { // initialize message to encrypt };
byte cipher[sizeof(plain)];
byte authTag[16];
int ret = wc_ChaCha20Poly1305_Encrypt(key, iv, inAAD, sizeof(inAAD),
plain, sizeof(plain), cipher, authTag);
if(ret != 0) {
// error running encrypt
}
function wc_ChaCha20Poly1305_Decrypt
int wc_ChaCha20Poly1305_Decrypt(
const byte inKey[CHACHA20_POLY1305_AEAD_KEYSIZE],
const byte inIV[CHACHA20_POLY1305_AEAD_IV_SIZE],
const byte * inAAD,
const word32 inAADLen,
const byte * inCiphertext,
const word32 inCiphertextLen,
const byte inAuthTag[CHACHA20_POLY1305_AEAD_AUTHTAG_SIZE],
byte * outPlaintext
)
This function decrypts input ciphertext, inCiphertext, using the ChaCha20 stream cipher, into the output buffer, outPlaintext. It also performs Poly-1305 authentication, comparing the given inAuthTag to an authentication generated with the inAAD (arbitrary length additional authentication data). Note: If the generated authentication tag does not match the supplied authentication tag, the text is not decrypted.
Parameters:
- inKey pointer to a buffer containing the 32 byte key to use for decryption
- inIv pointer to a buffer containing the 12 byte iv to use for decryption
- inAAD pointer to the buffer containing arbitrary length additional authenticated data (AAD)
- inAADLen length of the input AAD
- inCiphertext pointer to the buffer containing the ciphertext to decrypt
- outCiphertextLen the length of the ciphertext to decrypt
- inAuthTag pointer to the buffer containing the 16 byte digest for authentication
- outPlaintext pointer to the buffer in which to store the plaintext
See:
- wc_ChaCha20Poly1305_Encrypt
- wc_ChaCha_*
- wc_Poly1305*
Return:
- 0 Returned upon successfully decrypting the message
- BAD_FUNC_ARG Returned if any of the function arguments do not match what is expected
- MAC_CMP_FAILED_E Returned if the generated authentication tag does not match the supplied inAuthTag.
Example
byte key[] = { // initialize 32 byte key };
byte iv[] = { // initialize 12 byte key };
byte inAAD[] = { // initialize AAD };
byte cipher[] = { // initialize with received ciphertext };
byte authTag[16] = { // initialize with received authentication tag };
byte plain[sizeof(cipher)];
int ret = wc_ChaCha20Poly1305_Decrypt(key, iv, inAAD, sizeof(inAAD),
cipher, sizeof(cipher), authTag, plain);
if(ret == MAC_CMP_FAILED_E) {
// error during authentication
} else if( ret != 0) {
// error with function arguments
}
Updated on 2024-11-08 at 01:16:17 +0000