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TLS: Parse OCSPResponse to extract BasicOCSPResponse

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This adds the next step for OCSP stapling. The received OCSPResponse is
parsed to get the BasicOCSPResponse. This commit does not yet process
the BasicOCSPResponse.

Signed-off-by: Jouni Malinen <j@w1.fi>
This commit is contained in:
Jouni Malinen 2015-12-14 12:31:35 +02:00
parent d560288a44
commit 06f14421ea
1 changed files with 146 additions and 3 deletions
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149
src/tls/tlsv1_client_ocsp.c
View file

@ -10,17 +10,160 @@
#include "common.h"
#include "crypto/tls.h"
#include "asn1.h"
#include "tlsv1_common.h"
#include "tlsv1_record.h"
#include "tlsv1_client.h"
#include "tlsv1_client_i.h"
enum tls_ocsp_result tls_process_ocsp_response(struct tlsv1_client *conn,
const u8 *resp, size_t len)
/* RFC 6960, 4.2.1: OCSPResponseStatus ::= ENUMERATED */
enum ocsp_response_status {
OCSP_RESP_STATUS_SUCCESSFUL = 0,
OCSP_RESP_STATUS_MALFORMED_REQ = 1,
OCSP_RESP_STATUS_INT_ERROR = 2,
OCSP_RESP_STATUS_TRY_LATER = 3,
/* 4 not used */
OCSP_RESP_STATUS_SIG_REQUIRED = 5,
OCSP_RESP_STATUS_UNAUTHORIZED = 6,
};
static int is_oid_basic_ocsp_resp(struct asn1_oid *oid)
{
wpa_hexdump(MSG_MSGDUMP, "TLSv1: OCSPResponse", resp, len);
return oid->len == 10 &&
oid->oid[0] == 1 /* iso */ &&
oid->oid[1] == 3 /* identified-organization */ &&
oid->oid[2] == 6 /* dod */ &&
oid->oid[3] == 1 /* internet */ &&
oid->oid[4] == 5 /* security */ &&
oid->oid[5] == 5 /* mechanisms */ &&
oid->oid[6] == 7 /* id-pkix */ &&
oid->oid[7] == 48 /* id-ad */ &&
oid->oid[8] == 1 /* id-pkix-ocsp */ &&
oid->oid[9] == 1 /* id-pkix-ocsp-basic */;
}
static enum tls_ocsp_result
tls_process_basic_ocsp_response(struct tlsv1_client *conn, const u8 *resp,
size_t len)
{
wpa_hexdump(MSG_MSGDUMP, "OCSP: BasicOCSPResponse", resp, len);
/*
* RFC 6960, 4.2.1:
* BasicOCSPResponse ::= SEQUENCE {
* tbsResponseData ResponseData,
* signatureAlgorithm AlgorithmIdentifier,
* signature BIT STRING,
* certs [0] EXPLICIT SEQUENCE OF Certificate OPTIONAL }
*/
/* TODO */
return TLS_OCSP_NO_RESPONSE;
}
enum tls_ocsp_result tls_process_ocsp_response(struct tlsv1_client *conn,
const u8 *resp, size_t len)
{
struct asn1_hdr hdr;
const u8 *pos, *end;
u8 resp_status;
struct asn1_oid oid;
char obuf[80];
wpa_hexdump(MSG_MSGDUMP, "TLSv1: OCSPResponse", resp, len);
/*
* RFC 6960, 4.2.1:
* OCSPResponse ::= SEQUENCE {
* responseStatus OCSPResponseStatus,
* responseBytes [0] EXPLICIT ResponseBytes OPTIONAL }
*/
if (asn1_get_next(resp, len, &hdr) < 0 ||
hdr.class != ASN1_CLASS_UNIVERSAL ||
hdr.tag != ASN1_TAG_SEQUENCE) {
wpa_printf(MSG_DEBUG,
"OCSP: Expected SEQUENCE (OCSPResponse) - found class %d tag 0x%x",
hdr.class, hdr.tag);
return TLS_OCSP_INVALID;
}
pos = hdr.payload;
end = hdr.payload + hdr.length;
/* OCSPResponseStatus ::= ENUMERATED */
if (asn1_get_next(pos, end - pos, &hdr) < 0 ||
hdr.class != ASN1_CLASS_UNIVERSAL ||
hdr.tag != ASN1_TAG_ENUMERATED ||
hdr.length != 1) {
wpa_printf(MSG_DEBUG,
"OCSP: Expected ENUMERATED (responseStatus) - found class %d tag 0x%x length %u",
hdr.class, hdr.tag, hdr.length);
return TLS_OCSP_INVALID;
}
resp_status = hdr.payload[0];
wpa_printf(MSG_DEBUG, "OCSP: responseStatus %u", resp_status);
pos = hdr.payload + hdr.length;
if (resp_status != OCSP_RESP_STATUS_SUCCESSFUL) {
wpa_printf(MSG_DEBUG, "OCSP: No stapling result");
return TLS_OCSP_NO_RESPONSE;
}
/* responseBytes [0] EXPLICIT ResponseBytes OPTIONAL */
if (pos == end)
return TLS_OCSP_NO_RESPONSE;
if (asn1_get_next(pos, end - pos, &hdr) < 0 ||
hdr.class != ASN1_CLASS_CONTEXT_SPECIFIC ||
hdr.tag != 0) {
wpa_printf(MSG_DEBUG,
"OCSP: Expected [0] EXPLICIT (responseBytes) - found class %d tag 0x%x",
hdr.class, hdr.tag);
return TLS_OCSP_INVALID;
}
/*
* ResponseBytes ::= SEQUENCE {
* responseType OBJECT IDENTIFIER,
* response OCTET STRING }
*/
if (asn1_get_next(hdr.payload, hdr.length, &hdr) < 0 ||
hdr.class != ASN1_CLASS_UNIVERSAL ||
hdr.tag != ASN1_TAG_SEQUENCE) {
wpa_printf(MSG_DEBUG,
"OCSP: Expected SEQUENCE (ResponseBytes) - found class %d tag 0x%x",
hdr.class, hdr.tag);
return TLS_OCSP_INVALID;
}
pos = hdr.payload;
end = hdr.payload + hdr.length;
/* responseType OBJECT IDENTIFIER */
if (asn1_get_oid(pos, end - pos, &oid, &pos)) {
wpa_printf(MSG_DEBUG,
"OCSP: Failed to parse OID (responseType)");
return TLS_OCSP_INVALID;
}
asn1_oid_to_str(&oid, obuf, sizeof(obuf));
wpa_printf(MSG_DEBUG, "OCSP: responseType %s", obuf);
if (!is_oid_basic_ocsp_resp(&oid)) {
wpa_printf(MSG_DEBUG, "OCSP: Ignore unsupported response type");
return TLS_OCSP_NO_RESPONSE;
}
/* response OCTET STRING */
if (asn1_get_next(pos, end - pos, &hdr) < 0 ||
hdr.class != ASN1_CLASS_UNIVERSAL ||
hdr.tag != ASN1_TAG_OCTETSTRING) {
wpa_printf(MSG_DEBUG,
"OCSP: Expected OCTET STRING (response) - found class %d tag 0x%x",
hdr.class, hdr.tag);
return TLS_OCSP_INVALID;
}
return tls_process_basic_ocsp_response(conn, hdr.payload, hdr.length);
}