nts: refactor NTS context

Add a context structure for the algorithm and keys established by
NTS-KE. Modify the client to save the context and reset the SIV key to
the C2S/S2C key before each request/response instead of keeping two SIV
instances.

This will make it easier for the server to support different algorithms
and allow the client to save the context with cookies to disk.
This commit is contained in:
Miroslav Lichvar
2020-03-30 18:06:57 +02:00
parent 5296858411
commit adcf073484
10 changed files with 121 additions and 91 deletions

View File

@@ -49,8 +49,7 @@ struct NKC_Instance_Record {
int got_response;
int resolving_name;
SIV_Algorithm siv_algorithm;
NKE_Key c2s, s2c;
NKE_Context context;
NKE_Cookie cookies[NKE_MAX_COOKIES];
int num_cookies;
char server_name[NKE_MAX_RECORD_BODY_LENGTH + 1];
@@ -156,7 +155,7 @@ process_response(NKC_Instance inst)
break;
}
aead_algorithm = AEAD_AES_SIV_CMAC_256;
inst->siv_algorithm = aead_algorithm;
inst->context.algorithm = aead_algorithm;
break;
case NKE_RECORD_ERROR:
if (length == 2)
@@ -237,7 +236,8 @@ handle_message(void *arg)
return 0;
}
if (!NKSN_GetKeys(inst->session, inst->siv_algorithm, &inst->c2s, &inst->s2c))
if (!NKSN_GetKeys(inst->session, inst->context.algorithm,
&inst->context.c2s, &inst->context.s2c))
return 0;
if (inst->server_name[0] != '\0') {
@@ -371,8 +371,7 @@ NKC_IsActive(NKC_Instance inst)
/* ================================================== */
int
NKC_GetNtsData(NKC_Instance inst,
SIV_Algorithm *siv_algorithm, NKE_Key *c2s, NKE_Key *s2c,
NKC_GetNtsData(NKC_Instance inst, NKE_Context *context,
NKE_Cookie *cookies, int *num_cookies, int max_cookies,
IPSockAddr *ntp_address)
{
@@ -381,9 +380,7 @@ NKC_GetNtsData(NKC_Instance inst,
if (!inst->got_response || inst->resolving_name)
return 0;
*siv_algorithm = inst->siv_algorithm;
*c2s = inst->c2s;
*s2c = inst->s2c;
*context = inst->context;
for (i = 0; i < inst->num_cookies && i < max_cookies; i++)
cookies[i] = inst->cookies[i];