hi,
I want to only encrypr the raw audio data / payload using AES in pjsip. Can anyone plase help me where to do it in the code.Right now i am encrypting the data in
rec_cb in sound_port.c? as follows
?
SampleEncrypter(frame->buf,&dLength);
where
SampleEncrypter is a function that uses AES as follows
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? void SampleEncrypter(void *opaque,unsigned *opaque_len)
{
? aes_cbc_ctx_t aes_ctx;
? hmac_ctx_t hmac_ctx;
? unsigned char enc_key[ENC_KEY_LEN] ;?
? err_status_t status;
??? /* derive encryption and authentication keys from the input key */
?? char key [] = "encryption";
??? status = hmac_init(&hmac_ctx, key, KEY_LEN);
??? if (status) return ;
??? status = hmac_compute(&hmac_ctx, "ENC", 3, ENC_KEY_LEN, enc_key);
??? if (status) return ;??
??? /* set aes key */
??? status = aes_cbc_context_init(&aes_ctx, key, direction_encrypt);
??? if (status) return ;???
??? /* encrypt the opaque data? */
??? status = aes_cbc_nist_encrypt(&aes_ctx, opaque, opaque_len);
??? if (status) return ;????
}
?
?
and decrypting it in
play_cb as follows
?
?
status = pjmedia_port_get_frame(port, frame);
// calling decrypt after get_frame
SampleDecrypter(frame->buf,&dLength);
?
?
? void SampleDecrypter(void *opaque,unsigned *opaque_len)
{
? aes_cbc_ctx_t aes_ctx;
? hmac_ctx_t hmac_ctx;
? unsigned char enc_key[ENC_KEY_LEN];
? err_status_t status;
??? /* derive encryption and authentication keys from the input key */
?char key [] = "encryption";
? status = hmac_init(&hmac_ctx, key, KEY_LEN);
??? if (status) return ;
??? status = hmac_compute(&hmac_ctx, "ENC", 3, ENC_KEY_LEN, enc_key);
??? if (status) return;
??? /* set aes key */
??? status = aes_cbc_context_init(&aes_ctx, key, direction_decrypt);
??? if (status) return;
??? /* encrypt the opaque data? */
??? status = aes_cbc_nist_decrypt(&aes_ctx, opaque, opaque_len);
??? if (status) return;?
}
?
The result is a noise and nothing else.
?
Thanks and Regards
susheel tickoo
?
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