err_status_t
ctr_prng_init(rand_source_func_t random_source) {
uint8_t tmp_key[32];
err_status_t status;
/* initialize output count to zero */
ctr_prng.octet_count = 0;
/* set random source */
ctr_prng.rand = random_source;
/* initialize secret key from random source */
status = random_source(tmp_key, 32);
if (status)
return status;
/* initialize aes ctr context with random key */
#ifdef OPENSSL
status = aes_icm_openssl_context_init(&ctr_prng.state, tmp_key, 30);
#else
status = aes_icm_context_init(&ctr_prng.state, tmp_key, 30);
#endif
if (status)
return status;
return err_status_ok;
}
static ismacryp_rc_t initSessionData (ismacryp_session_id_t session,
ismacryp_session_t *sp,
ismacryp_keytype_t keytype)
{
#ifdef HAVE_SRTP
FILE *fp;
int i;
char kms_data_file[KMS_DATA_FILE_FILENAME_MAX_LEN];
char kms_data[KMS_DATA_FILE_MAX_LINE_LEN+1];
char temp[25];
err_status_t rc = err_status_ok;
size_t pathlen;
size_t filenamelen;
int foundKey = FALSE;
int len;
#endif
sp->sessid = session;
sp->next = NULL;
sp->prev = NULL;
#ifdef HAVE_SRTP
// get the key material
// NULL case, key and salt have been memset to 0, nothing breaks.
strncpy(kms_data_file,getenv("HOME"),KMS_DATA_FILE_FILENAME_MAX_LEN);
pathlen = strlen(kms_data_file);
filenamelen = strlen(KMS_DATA_FILE);
if ( (pathlen + filenamelen + 1) > KMS_DATA_FILE_FILENAME_MAX_LEN ) { // +1 for '/'
fprintf(stdout,"key file name too long\n");
return ismacryp_rc_keyfilename_error;
}
kms_data_file[pathlen+1] = kms_data_file[pathlen];
kms_data_file[pathlen] = '/';
strncpy(&kms_data_file[pathlen+1], KMS_DATA_FILE, filenamelen );
switch( keytype) {
case KeyTypeVideo:
strcpy(temp,KMS_DATA_VIDEOKEY_STR);
break;
case KeyTypeAudio:
strcpy(temp,KMS_DATA_AUDIOKEY_STR);
break;
case KeyTypeOther:
default:
fprintf(stdout,"Unsupported key type: %d\n",keytype);
return ismacryp_rc_keytype_error;
}
if ( !(fp=fopen(kms_data_file,"r")) ) {
fprintf(stdout,"Can't open kms file: %s\n",kms_data_file);
return(ismacryp_rc_keyfile_error);
}
i = 0;
while ( fgets(kms_data,KMS_DATA_FILE_MAX_LINE_LEN,fp)) {
len = strlen(kms_data);
kms_data[len-1] = kms_data[len]; // get rid of newline
i++;
if ( !strncmp(kms_data, temp, strlen(KMS_DATA_AUDIOKEY_STR)) ) {
for (i=0;i<AES_KEY_SALT_LEN;i++) {
uint temp;
fscanf(fp, "%x", &temp);
sp->kk.aes_overlay[i] = temp;
}
foundKey = TRUE;
break;
}
}
if ( !foundKey ) {
fprintf(stdout, "Can't find %s\n", temp);
fclose(fp);
return ismacryp_rc_key_error;
}
fclose(fp);
#endif
sp->keycount = 1;
sp->sample_count = 0;
sp->BSO = 0;
sp->IV_len = ISMACRYP_DEFAULT_IV_LENGTH;
sp->deltaIV_len = ISMACRYP_DEFAULT_DELTA_IV_LENGTH;
sp->key_type = keytype;
sp->selective_enc = FALSE;
#ifdef HAVE_SRTP
// Allocate cipher.
//fprintf(stdout," - allocate cipher for session %d\n", session);
rc=aes_icm_alloc_ismacryp(&(sp->cp), AES_KEY_SALT_LEN, 1);
if ( rc != err_status_ok ) {
fprintf(stdout," - allocate cipher for session %d FAILED rc = %d\n", session,
rc );
return ismacryp_rc_cipheralloc_error;
}
// Init cipher.
rc=aes_icm_context_init(sp->cp->state, sp->kk.aes_overlay);
if ( rc != err_status_ok ) {
fprintf(stdout," - init cipher for session %d FAILED rc = %d\n", session,
rc );
return ismacryp_rc_cipherinit_error;
}
#endif
return ismacryp_rc_ok;
}
