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Calculate cookie in SendStatelessReplyDtls13()

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Not touching ssl->hsHashes while in stateless mode
This commit is contained in:
Juliusz Sosinowicz
2023-01-24 20:24:50 +01:00
parent c15043b191
commit 57dccc4cf4
5 changed files with 109 additions and 64 deletions
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32
src/dtls.c
View File

@ -492,9 +492,10 @@ static int SendStatelessReplyDtls13(const WOLFSSL* ssl, WolfSSL_CH* ch,
#endif
CipherSuite cs;
CipherSpecs specs;
byte cookieHash[WC_MAX_DIGEST_SIZE];
int cookieHashSz;
XMEMSET(&cs, 0, sizeof(cs));
XMEMSET(&specs, 0, sizeof(specs));
/* We need to echo the session ID sent by the client */
if (ch->sessionId.size > ID_LEN) {
@ -502,12 +503,6 @@ static int SendStatelessReplyDtls13(const WOLFSSL* ssl, WolfSSL_CH* ch,
ERROR_OUT(INVALID_PARAMETER, dtls13_cleanup);
}
/* Hashes are reset in SendTls13ServerHello when sending a HRR */
ret = Dtls13HashHandshakeType((WOLFSSL*)ssl, ch->raw, ch->length,
client_hello);
if (ret != 0)
goto dtls13_cleanup;
/* Populate the suites struct to find a common ciphersuite */
XMEMSET(&suites, 0, sizeof(suites));
suites.suiteSz = (word16)ch->cipherSuite.size;
@ -659,13 +654,28 @@ static int SendStatelessReplyDtls13(const WOLFSSL* ssl, WolfSSL_CH* ch,
TLSX_Remove(&parsedExts, TLSX_KEY_SHARE, ssl->heap);
}
/* This is required to correctly generate the hash */
ret = SetCipherSpecs_ex(WOLFSSL_SERVER_END, cs.cipherSuite0,
cs.cipherSuite, &specs, NULL);
if (ret != 0)
goto dtls13_cleanup;
/* Calculate the cookie hash */
ret = Dtls13HashClientHello(ssl, cookieHash, &cookieHashSz, ch->raw,
ch->length, &specs);
if (ret != 0)
goto dtls13_cleanup;
/* Push the cookie to extensions */
ret = CreateCookieExt(ssl, cookieHash, cookieHashSz, &parsedExts,
cs.cipherSuite0, cs.cipherSuite);
if (ret != 0)
goto dtls13_cleanup;
{
WOLFSSL* nonConstSSL = (WOLFSSL*)ssl;
TLSX* sslExts = nonConstSSL->extensions;
/* This is required to correctly generate the hash */
ret = SetCipherSpecs_ex(WOLFSSL_SERVER_END, cs.cipherSuite0,
cs.cipherSuite, &nonConstSSL->specs, NULL);
if (ret != 0)
goto dtls13_cleanup;
nonConstSSL->options.tls = 1;
@ -684,8 +694,6 @@ static int SendStatelessReplyDtls13(const WOLFSSL* ssl, WolfSSL_CH* ch,
/* Can be modified inside SendTls13ServerHello */
parsedExts = nonConstSSL->extensions;
InitCipherSpecs(&nonConstSSL->specs);
nonConstSSL->session->sessionIDSz = 0;
nonConstSSL->options.cipherSuite0 = 0;
nonConstSSL->options.cipherSuite = 0;

30
src/dtls13.c
View File

@ -437,24 +437,36 @@ static int Dtls13SendNow(WOLFSSL* ssl, enum HandShakeType handshakeType)
/* Handshake header DTLS only fields are not inlcuded in the transcript hash.
* body points to the body of the DTLSHandshake message. */
int Dtls13HashHandshakeType(WOLFSSL* ssl, const byte* body, word32 length,
enum HandShakeType handshakeType)
int Dtls13HashClientHello(const WOLFSSL* ssl, byte* hash, int* hashSz,
const byte* body, word32 length, CipherSpecs* specs)
{
/* msg_type(1) + length (3) */
byte header[OPAQUE32_LEN];
int ret;
wc_HashAlg hashCtx;
int type = wolfSSL_GetHmacType_ex(specs);
header[0] = (byte)handshakeType;
header[0] = (byte)client_hello;
c32to24(length, header + 1);
ret = HashRaw(ssl, header, OPAQUE32_LEN);
if (ret != 0)
return ret;
return HashRaw(ssl, body, length);
ret = wc_HashInit_ex(&hashCtx, type, ssl->heap, ssl->devId);
if (ret == 0) {
ret = wc_HashUpdate(&hashCtx, type, header, OPAQUE32_LEN);
if (ret == 0)
ret = wc_HashUpdate(&hashCtx, type, body, length);
if (ret == 0)
ret = wc_HashFinal(&hashCtx, type, hash);
if (ret == 0) {
*hashSz = wc_HashGetDigestSize(type);
if (*hashSz < 0)
ret = *hashSz;
}
wc_HashFree(&hashCtx, type);
}
return ret;
}
/* Handshake header DTLS only fields are not inlcuded in the transcript hash */
/* Handshake header DTLS only fields are not included in the transcript hash */
int Dtls13HashHandshake(WOLFSSL* ssl, const byte* input, word16 length)
{
int ret;

17
src/tls.c
View File

@ -663,14 +663,12 @@ int wolfSSL_make_eap_keys(WOLFSSL* ssl, void* msk, unsigned int len,
return ret;
}
/* return HMAC digest type in wolfSSL format */
int wolfSSL_GetHmacType(WOLFSSL* ssl)
int wolfSSL_GetHmacType_ex(CipherSpecs* specs)
{
if (ssl == NULL)
if (specs == NULL)
return BAD_FUNC_ARG;
switch (ssl->specs.mac_algorithm) {
switch (specs->mac_algorithm) {
#ifndef NO_MD5
case md5_mac:
{
@ -709,6 +707,15 @@ int wolfSSL_GetHmacType(WOLFSSL* ssl)
}
}
/* return HMAC digest type in wolfSSL format */
int wolfSSL_GetHmacType(WOLFSSL* ssl)
{
if (ssl == NULL)
return BAD_FUNC_ARG;
return wolfSSL_GetHmacType_ex(&ssl->specs);
}
int wolfSSL_SetTlsHmacInner(WOLFSSL* ssl, byte* inner, word32 sz, int content,
int verify)

84
src/tls13.c
View File

@ -3337,14 +3337,34 @@ byte SuiteMac(const byte* suite)
* hashSz The size of the hash data in bytes.
* returns 0 on success, otherwise failure.
*/
static int CreateCookieExt(const WOLFSSL* ssl, byte* hash, word16 hashSz,
TLSX** exts)
int CreateCookieExt(const WOLFSSL* ssl, byte* hash, word16 hashSz,
TLSX** exts, byte cipherSuite0, byte cipherSuite)
{
int ret;
byte mac[WC_MAX_DIGEST_SIZE] = {0};
Hmac cookieHmac;
byte cookieType = 0;
byte macSz = 0;
byte cookie[OPAQUE8_LEN + WC_MAX_DIGEST_SIZE + OPAQUE16_LEN * 2];
TLSX* ext;
word16 cookieSz = 0;
/* Cookie Data = Hash Len | Hash | CS | KeyShare Group */
cookie[cookieSz++] = hashSz;
XMEMCPY(cookie + cookieSz, hash, hashSz);
cookieSz += hashSz;
cookie[cookieSz++] = cipherSuite0;
cookie[cookieSz++] = cipherSuite;
if ((ext = TLSX_Find(*exts, TLSX_KEY_SHARE)) != NULL) {
KeyShareEntry* kse = (KeyShareEntry*)ext->data;
if (kse == NULL) {
WOLFSSL_MSG("KeyShareEntry can't be empty when negotiating "
"parameters");
return BAD_STATE_E;
}
c16toa(kse->group, cookie + cookieSz);
cookieSz += OPAQUE16_LEN;
}
#if !defined(NO_SHA) && defined(NO_SHA256)
cookieType = SHA;
@ -3362,7 +3382,7 @@ static int CreateCookieExt(const WOLFSSL* ssl, byte* hash, word16 hashSz,
ssl->buffers.tls13CookieSecret.length);
}
if (ret == 0)
ret = wc_HmacUpdate(&cookieHmac, hash, hashSz);
ret = wc_HmacUpdate(&cookieHmac, cookie, cookieSz);
#ifdef WOLFSSL_DTLS13
/* Tie cookie to peer address */
if (ret == 0) {
@ -3381,7 +3401,7 @@ static int CreateCookieExt(const WOLFSSL* ssl, byte* hash, word16 hashSz,
return ret;
/* The cookie data is the hash and the integrity check. */
return TLSX_Cookie_Use(ssl, hash, hashSz, mac, macSz, 1, exts);
return TLSX_Cookie_Use(ssl, cookie, cookieSz, mac, macSz, 1, exts);
}
#endif
@ -3391,16 +3411,13 @@ static int CreateCookieExt(const WOLFSSL* ssl, byte* hash, word16 hashSz,
#define HRR_MAX_HS_HEADER_SZ HANDSHAKE_HEADER_SZ
#endif /* WOLFSSL_DTLS13 */
static int CreateCookieHash(const WOLFSSL* ssl, byte** hash, byte* hashSz,
static int CreateCookie(const WOLFSSL* ssl, byte** hash, byte* hashSz,
Hashes* hashes, TLSX** exts)
{
int ret;
int ret = 0;
(void)exts;
ret = BuildCertHashes(ssl, hashes);
if (ret != 0)
return ret;
*hash = NULL;
switch (ssl->specs.mac_algorithm) {
#ifndef NO_SHA256
@ -3426,30 +3443,9 @@ static int CreateCookieHash(const WOLFSSL* ssl, byte** hash, byte* hashSz,
return BAD_FUNC_ARG;
#if defined(WOLFSSL_SEND_HRR_COOKIE) && !defined(NO_WOLFSSL_SERVER)
if (ssl->options.sendCookie && ssl->options.side == WOLFSSL_SERVER_END) {
byte cookie[OPAQUE8_LEN + WC_MAX_DIGEST_SIZE + OPAQUE16_LEN * 2];
TLSX* ext;
word16 idx = 0;
/* Cookie Data = Hash Len | Hash | CS | KeyShare Group */
cookie[idx++] = *hashSz;
if (*hash)
XMEMCPY(cookie + idx, *hash, *hashSz);
idx += *hashSz;
cookie[idx++] = ssl->options.cipherSuite0;
cookie[idx++] = ssl->options.cipherSuite;
if ((ext = TLSX_Find(ssl->extensions, TLSX_KEY_SHARE)) != NULL) {
KeyShareEntry* kse = (KeyShareEntry*)ext->data;
if (kse == NULL) {
WOLFSSL_MSG("KeyShareEntry can't be empty when negotiating "
"parameters");
return BAD_STATE_E;
}
c16toa(kse->group, cookie + idx);
idx += OPAQUE16_LEN;
}
ret = CreateCookieExt(ssl, cookie, idx, exts);
}
if (ssl->options.sendCookie && ssl->options.side == WOLFSSL_SERVER_END)
ret = CreateCookieExt(ssl, *hash, *hashSz, exts,
ssl->options.cipherSuite0, ssl->options.cipherSuite);
#endif
return ret;
}
@ -3467,7 +3463,10 @@ int RestartHandshakeHash(WOLFSSL* ssl)
byte* hash = NULL;
byte hashSz = 0;
ret = CreateCookieHash(ssl, &hash, &hashSz, &hashes, &ssl->extensions);
ret = BuildCertHashes(ssl, &hashes);
if (ret != 0)
return ret;
ret = CreateCookie(ssl, &hash, &hashSz, &hashes, &ssl->extensions);
if (ret != 0)
return ret;
#if defined(WOLFSSL_SEND_HRR_COOKIE) && !defined(NO_WOLFSSL_SERVER)
@ -6883,7 +6882,13 @@ int SendTls13ServerHello(WOLFSSL* ssl, byte extMsgType)
WOLFSSL_START(WC_FUNC_SERVER_HELLO_SEND);
WOLFSSL_ENTER("SendTls13ServerHello");
if (extMsgType == hello_retry_request) {
/* When ssl->options.dtlsStateful is not set then cookie is calculated in
* dtls.c */
if (extMsgType == hello_retry_request
#ifdef WOLFSSL_DTLS13
&& (!ssl->options.dtls || ssl->options.dtlsStateful)
#endif
) {
WOLFSSL_MSG("wolfSSL Sending HelloRetryRequest");
if ((ret = RestartHandshakeHash(ssl)) < 0)
return ret;
@ -6970,7 +6975,14 @@ int SendTls13ServerHello(WOLFSSL* ssl, byte extMsgType)
if (ssl->options.sendCookie && extMsgType == hello_retry_request) {
/* Reset the hashes from here. We will be able to restart the hashes
* from the cookie in RestartHandshakeHashWithCookie */
ret = InitHandshakeHashes(ssl);
#ifdef WOLFSSL_DTLS13
/* When ssl->options.dtlsStateful is not set then cookie is calculated
* in dtls.c */
if (ssl->options.dtls && !ssl->options.dtlsStateful)
ret = 0;
else
#endif
ret = InitHandshakeHashes(ssl);
}
else
#endif

10
wolfssl/internal.h
View File

@ -5863,6 +5863,10 @@ WOLFSSL_LOCAL int cipherExtraData(WOLFSSL* ssl);
WOLFSSL_LOCAL int SendHelloVerifyRequest(WOLFSSL* ssl,
const byte* cookie, byte cookieSz);
WOLFSSL_LOCAL int CreateCookieExt(const WOLFSSL* ssl, byte* hash,
word16 hashSz, TLSX** exts,
byte cipherSuite0, byte cipherSuite);
#if !defined(NO_WOLFSSL_SERVER)
WOLFSSL_LOCAL int DoClientHelloStateless(WOLFSSL* ssl,
const byte* input, word32* inOutIdx, word32 helloSz);
@ -6128,8 +6132,8 @@ WOLFSSL_LOCAL int Dtls13RtxProcessingCertificate(WOLFSSL* ssl, byte* input,
word32 inputSize);
WOLFSSL_LOCAL int Dtls13HashHandshake(WOLFSSL* ssl, const byte* input,
word16 length);
WOLFSSL_LOCAL int Dtls13HashHandshakeType(WOLFSSL* ssl, const byte* body,
word32 length, enum HandShakeType handshakeType);
WOLFSSL_LOCAL int Dtls13HashClientHello(const WOLFSSL* ssl, byte* hash,
int* hashSz, const byte* body, word32 length, CipherSpecs* specs);
WOLFSSL_LOCAL void Dtls13FreeFsmResources(WOLFSSL* ssl);
WOLFSSL_LOCAL int Dtls13RtxTimeout(WOLFSSL* ssl);
WOLFSSL_LOCAL int Dtls13ProcessBufferedMessages(WOLFSSL* ssl);
@ -6218,6 +6222,8 @@ WOLFSSL_LOCAL int FindPskSuite(const WOLFSSL* ssl, PreSharedKey* psk,
byte* foundSuite);
#endif
WOLFSSL_LOCAL int wolfSSL_GetHmacType_ex(CipherSpecs* specs);
#ifdef __cplusplus
} /* extern "C" */
#endif