1.44 CRYPT_TDES_IvSet Function

C

int CRYPT_TDES_IvSet(
    CRYPT_TDES_CTX* tdes,
    const unsigned char* iv
);

Description

This function changes the initialization vector (IV) of a TDES context, but leaves the key alone.

Preconditions

None.

Parameters

ParametersDescription
tdesPointer to context which saves state between calls.
ivPointer to buffer holding the initialization vector. Must be 8 bytes in size.

Returns

  • BAD_FUNC_ARG - An invalid pointer was passed to the function
  • 0 - An invalid pointer was not passed to the function

Remarks

The IV must be 8 bytes long.

Example

CRYPT_TDES_CTX mcDes3;
int            ret;
byte           out1[TDES_SIZE];
byte           out2[TDES_SIZE];

strncpy((char*)key, "1234567890abcdefghijklmn", 24);
strncpy((char*)iv,  "12345678", 8);

ret = CRYPT_TDES_KeySet(&mcDes3, key, iv, CRYPT_TDES_ENCRYPTION);
ret = CRYPT_TDES_IvSet(&mcDes3, iv);
ret = CRYPT_TDES_CBC_Encrypt(&mcDes3, out1, ourData, TDES_SIZE);
ret = CRYPT_TDES_KeySet(&mcDes3, key, iv, CRYPT_TDES_DECRYPTION);
ret = CRYPT_TDES_CBC_Decrypt(&mcDes3, out2, out1, TDES_TEST_SIZE);