| 39 | } |
| 40 | |
| 41 | int JLSRTP::resetPseudoRandomState(std::vector<unsigned char> iv) |
| 42 | { |
| 43 | unsigned int ivSize = 0; |
| 44 | |
| 45 | ivSize = iv.size(); |
| 46 | assert(ivSize == JLSRTP_SALTING_KEY_LENGTH); |
| 47 | if (ivSize == JLSRTP_SALTING_KEY_LENGTH) |
| 48 | { |
| 49 | // aes_ctr128_encrypt() requires 'num' and 'ecount' to be set to zero on the first call |
| 50 | _pseudorandomstate.num = 0; |
| 51 | memset(_pseudorandomstate.ecount, 0, sizeof(_pseudorandomstate.ecount)); |
| 52 | |
| 53 | // Clear BOTH high-order bytes [0..13] for 'IV' AND low-order bytes [14..15] for 'counter' |
| 54 | memset(_pseudorandomstate.ivec, 0, AES_BLOCK_SIZE); |
| 55 | // Copy 'IV' into high-order bytes [0..13] -- low-order bytes [14..15] remain zero |
| 56 | memcpy(_pseudorandomstate.ivec, iv.data(), iv.size()); |
| 57 | |
| 58 | return 0; |
| 59 | } |
| 60 | else |
| 61 | { |
| 62 | return -1; |
| 63 | } |
| 64 | } |
| 65 | |
| 66 | int JLSRTP::pseudorandomFunction(std::vector<unsigned char> iv, int n, std::vector<unsigned char> &output) |
| 67 | { |