bad_dtls_test.c
/*
* Copyright 2016 The OpenSSL Project Authors. All Rights Reserved.
*
* Licensed under the OpenSSL license (the "License"). You may not use
* this file except in compliance with the License. You can obtain a copy
* in the file LICENSE in the source distribution or at
* https://www.openssl.org/source/license.html
*/
/*
* Unit test for Cisco DTLS1_BAD_VER session resume, as used by
* AnyConnect VPN protocol.
*
* This is designed to exercise the code paths in
* http://git.infradead.org/users/dwmw2/openconnect.git/blob/HEAD:/dtls.c
* which have frequently been affected by regressions in DTLS1_BAD_VER
* support.
*
* Note that unlike other SSL tests, we don't test against our own SSL
* server method. Firstly because we don't have one; we *only* support
* DTLS1_BAD_VER as a client. And secondly because even if that were
* fixed up it's the wrong thing to test against — because if changes
* are made in generic DTLS code which don't take DTLS1_BAD_VER into
* account, there's plenty of scope for making those changes such that
* they break *both* the client and the server in the same way.
*
* So we handle the server side manually. In a session resume there isn't
* much to be done anyway.
*/
#include <string.h>
/* On Windows this will include <winsock2.h> and thus it needs to be
* included *before* anything that includes <windows.h>. Ick. */
#include "e_os.h" /* for 'inline' */
#include <openssl/bio.h>
#include <openssl/crypto.h>
#include <openssl/evp.h>
#include <openssl/ssl.h>
#include <openssl/err.h>
#include <openssl/rand.h>
/* PACKET functions lifted from OpenSSL 1.1's ssl/packet_locl.h */
typedef struct {
/* Pointer to where we are currently reading from */
const unsigned char *curr;
/* Number of bytes remaining */
size_t remaining;
} PACKET;
/* Internal unchecked shorthand; don't use outside this file. */
static inline void packet_forward(PACKET *pkt, size_t len)
{
pkt->curr += len;
pkt->remaining -= len;
}
/*
* Returns the number of bytes remaining to be read in the PACKET
*/
static inline size_t PACKET_remaining(const PACKET *pkt)
{
return pkt->remaining;
}
/*
* Initialise a PACKET with |len| bytes held in |buf|. This does not make a
* copy of the data so |buf| must be present for the whole time that the PACKET
* is being used.
*/
static inline int PACKET_buf_init(PACKET *pkt,
const unsigned char *buf,
size_t len)
{
/* Sanity check for negative values. */
if (len > (size_t)65536)
return 0;
pkt->curr = buf;
pkt->remaining = len;
return 1;
}
/*
* Returns 1 if the packet has length |num| and its contents equal the |num|
* bytes read from |ptr|. Returns 0 otherwise (lengths or contents not equal).
* If lengths are equal, performs the comparison in constant time.
*/
static inline int PACKET_equal(const PACKET *pkt, const void *ptr,
size_t num)
{
if (PACKET_remaining(pkt) != num)
return 0;
return CRYPTO_memcmp(pkt->curr, ptr, num) == 0;
}
/*
* Peek ahead at 2 bytes in network order from |pkt| and store the value in
* |*data|
*/
static inline int PACKET_peek_net_2(const PACKET *pkt,
unsigned int *data)
{
if (PACKET_remaining(pkt) < 2)
return 0;
*data = ((unsigned int)(*pkt->curr)) << 8;
*data |= *(pkt->curr + 1);
return 1;
}
/* Equivalent of n2s */
/* Get 2 bytes in network order from |pkt| and store the value in |*data| */
static inline int PACKET_get_net_2(PACKET *pkt,
unsigned int *data)
{
if (!PACKET_peek_net_2(pkt, data))
return 0;
packet_forward(pkt, 2);
return 1;
}
/* Peek ahead at 1 byte from |pkt| and store the value in |*data| */
static inline int PACKET_peek_1(const PACKET *pkt,
unsigned int *data)
{
if (!PACKET_remaining(pkt))
return 0;
*data = *pkt->curr;
return 1;
}
/* Get 1 byte from |pkt| and store the value in |*data| */
static inline int PACKET_get_1(PACKET *pkt, unsigned int *data)
{
if (!PACKET_peek_1(pkt, data))
return 0;
packet_forward(pkt, 1);
return 1;
}
/*
* Peek ahead at |len| bytes from the |pkt| and store a pointer to them in
* |*data|. This just points at the underlying buffer that |pkt| is using. The
* caller should not free this data directly (it will be freed when the
* underlying buffer gets freed
*/
static inline int PACKET_peek_bytes(const PACKET *pkt,
const unsigned char **data,
size_t len)
{
if (PACKET_remaining(pkt) < len)
return 0;
*data = pkt->curr;
return 1;
}
/*
* Read |len| bytes from the |pkt| and store a pointer to them in |*data|. This
* just points at the underlying buffer that |pkt| is using. The caller should
* not free this data directly (it will be freed when the underlying buffer gets
* freed
*/
static inline int PACKET_get_bytes(PACKET *pkt,
const unsigned char **data,
size_t len)
{
if (!PACKET_peek_bytes(pkt, data, len))
return 0;
packet_forward(pkt, len);
return 1;
}
/* Peek ahead at |len| bytes from |pkt| and copy them to |data| */
static inline int PACKET_peek_copy_bytes(const PACKET *pkt,
unsigned char *data,
size_t len)
{
if (PACKET_remaining(pkt) < len)
return 0;
memcpy(data, pkt->curr, len);
return 1;
}
/*
* Read |len| bytes from |pkt| and copy them to |data|.
* The caller is responsible for ensuring that |data| can hold |len| bytes.
*/
static inline int PACKET_copy_bytes(PACKET *pkt,
unsigned char *data,
size_t len)
{
if (!PACKET_peek_copy_bytes(pkt, data, len))
return 0;
packet_forward(pkt, len);
return 1;
}
/* Move the current reading position forward |len| bytes */
static inline int PACKET_forward(PACKET *pkt, size_t len)
{
if (PACKET_remaining(pkt) < len)
return 0;
packet_forward(pkt, len);
return 1;
}
/*
* Reads a variable-length vector prefixed with a one-byte length, and stores
* the contents in |subpkt|. |pkt| can equal |subpkt|.
* Data is not copied: the |subpkt| packet will share its underlying buffer with
* the original |pkt|, so data wrapped by |pkt| must outlive the |subpkt|.
* Upon failure, the original |pkt| and |subpkt| are not modified.
*/
static inline int PACKET_get_length_prefixed_1(PACKET *pkt,
PACKET *subpkt)
{
unsigned int length;
const unsigned char *data;
PACKET tmp = *pkt;
if (!PACKET_get_1(&tmp, &length) ||
!PACKET_get_bytes(&tmp, &data, (size_t)length)) {
return 0;
}
*pkt = tmp;
subpkt->curr = data;
subpkt->remaining = length;
return 1;
}
#define OSSL_NELEM(x) (sizeof(x)/sizeof(x[0]))
/* For DTLS1_BAD_VER packets the MAC doesn't include the handshake header */
#define MAC_OFFSET (DTLS1_RT_HEADER_LENGTH + DTLS1_HM_HEADER_LENGTH)
static unsigned char client_random[SSL3_RANDOM_SIZE];
static unsigned char server_random[SSL3_RANDOM_SIZE];
/* These are all generated locally, sized purely according to our own whim */
static unsigned char session_id[32];
static unsigned char master_secret[48];
static unsigned char cookie[20];
/* We've hard-coded the cipher suite; we know it's 104 bytes */
static unsigned char key_block[104];
#define mac_key (key_block + 20)
#define dec_key (key_block + 40)
#define enc_key (key_block + 56)
static EVP_MD_CTX handshake_md5;
static EVP_MD_CTX handshake_sha1;
/* PRF lifted from ssl/t1_enc.c since we can't easily use it directly */
static int tls1_P_hash(const EVP_MD *md, const unsigned char *sec,
int sec_len,
const void *seed1, int seed1_len,
const void *seed2, int seed2_len,
const void *seed3, int seed3_len,
unsigned char *out, int olen)
{
int chunk;
size_t j;
EVP_MD_CTX ctx, ctx_tmp, ctx_init;
EVP_PKEY *prf_mac_key;
unsigned char A1[EVP_MAX_MD_SIZE];
size_t A1_len;
int ret = 0;
chunk = EVP_MD_size(md);
OPENSSL_assert(chunk >= 0);
EVP_MD_CTX_init(&ctx);
EVP_MD_CTX_init(&ctx_tmp);
EVP_MD_CTX_init(&ctx_init);
EVP_MD_CTX_set_flags(&ctx_init, EVP_MD_CTX_FLAG_NON_FIPS_ALLOW);
prf_mac_key = EVP_PKEY_new_mac_key(EVP_PKEY_HMAC, NULL, sec, sec_len);
if (!prf_mac_key)
goto err;
if (!EVP_DigestSignInit(&ctx_init, NULL, md, NULL, prf_mac_key))
goto err;
if (!EVP_MD_CTX_copy_ex(&ctx, &ctx_init))
goto err;
if (seed1 && !EVP_DigestSignUpdate(&ctx, seed1, seed1_len))
goto err;
if (seed2 && !EVP_DigestSignUpdate(&ctx, seed2, seed2_len))
goto err;
if (seed3 && !EVP_DigestSignUpdate(&ctx, seed3, seed3_len))
goto err;
if (!EVP_DigestSignFinal(&ctx, A1, &A1_len))
goto err;
for (;;) {
/* Reinit mac contexts */
if (!EVP_MD_CTX_copy_ex(&ctx, &ctx_init))
goto err;
if (!EVP_DigestSignUpdate(&ctx, A1, A1_len))
goto err;
if (olen > chunk && !EVP_MD_CTX_copy_ex(&ctx_tmp, &ctx))
goto err;
if (seed1 && !EVP_DigestSignUpdate(&ctx, seed1, seed1_len))
goto err;
if (seed2 && !EVP_DigestSignUpdate(&ctx, seed2, seed2_len))
goto err;
if (seed3 && !EVP_DigestSignUpdate(&ctx, seed3, seed3_len))
goto err;
if (olen > chunk) {
if (!EVP_DigestSignFinal(&ctx, out, &j))
goto err;
out += j;
olen -= j;
/* calc the next A1 value */
if (!EVP_DigestSignFinal(&ctx_tmp, A1, &A1_len))
goto err;
} else { /* last one */
if (!EVP_DigestSignFinal(&ctx, A1, &A1_len))
goto err;
memcpy(out, A1, olen);
break;
}
}
ret = 1;
err:
EVP_PKEY_free(prf_mac_key);
EVP_MD_CTX_cleanup(&ctx);
EVP_MD_CTX_cleanup(&ctx_tmp);
EVP_MD_CTX_cleanup(&ctx_init);
OPENSSL_cleanse(A1, sizeof(A1));
return ret;
}
/* seed1 through seed5 are virtually concatenated */
static int do_PRF(const void *seed1, int seed1_len,
const void *seed2, int seed2_len,
const void *seed3, int seed3_len,
unsigned char *out, int olen)
{
unsigned char out2[104];
int i, len;
if (olen > (int)sizeof(out2))
return 0;
len = sizeof(master_secret) / 2;
if (!tls1_P_hash(EVP_md5(), master_secret, len,
seed1, seed1_len, seed2, seed2_len, seed3,
seed3_len, out, olen))
return 0;
if (!tls1_P_hash(EVP_sha1(), master_secret + len, len,
seed1, seed1_len, seed2, seed2_len, seed3,
seed3_len, out2, olen))
return 0;
for (i = 0; i < olen; i++) {
out[i] ^= out2[i];
}
return 1;
}
static SSL_SESSION *client_session(void)
{
static unsigned char session_asn1[] = {
0x30, 0x5F, /* SEQUENCE, length 0x5F */
0x02, 0x01, 0x01, /* INTEGER, SSL_SESSION_ASN1_VERSION */
0x02, 0x02, 0x01, 0x00, /* INTEGER, DTLS1_BAD_VER */
0x04, 0x02, 0x00, 0x2F, /* OCTET_STRING, AES128-SHA */
0x04, 0x20, /* OCTET_STRING, session id */
#define SS_SESSID_OFS 15 /* Session ID goes here */
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
0x04, 0x30, /* OCTET_STRING, master secret */
#define SS_SECRET_OFS 49 /* Master secret goes here */
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
};
const unsigned char *p = session_asn1;
/* Copy the randomly-generated fields into the above ASN1 */
memcpy(session_asn1 + SS_SESSID_OFS, session_id, sizeof(session_id));
memcpy(session_asn1 + SS_SECRET_OFS, master_secret, sizeof(master_secret));
return d2i_SSL_SESSION(NULL, &p, sizeof(session_asn1));
}
/* Returns 1 for initial ClientHello, 2 for ClientHello with cookie */
static int validate_client_hello(BIO *wbio)
{
PACKET pkt, pkt2;
long len;
unsigned char *data;
int cookie_found = 0;
unsigned int u;
len = BIO_get_mem_data(wbio, (char **)&data);
if (!PACKET_buf_init(&pkt, data, len))
return 0;
/* Check record header type */
if (!PACKET_get_1(&pkt, &u) || u != SSL3_RT_HANDSHAKE)
return 0;
/* Version */
if (!PACKET_get_net_2(&pkt, &u) || u != DTLS1_BAD_VER)
return 0;
/* Skip the rest of the record header */
if (!PACKET_forward(&pkt, DTLS1_RT_HEADER_LENGTH - 3))
return 0;
/* Check it's a ClientHello */
if (!PACKET_get_1(&pkt, &u) || u != SSL3_MT_CLIENT_HELLO)
return 0;
/* Skip the rest of the handshake message header */
if (!PACKET_forward(&pkt, DTLS1_HM_HEADER_LENGTH - 1))
return 0;
/* Check client version */
if (!PACKET_get_net_2(&pkt, &u) || u != DTLS1_BAD_VER)
return 0;
/* Store random */
if (!PACKET_copy_bytes(&pkt, client_random, SSL3_RANDOM_SIZE))
return 0;
/* Check session id length and content */
if (!PACKET_get_length_prefixed_1(&pkt, &pkt2) ||
!PACKET_equal(&pkt2, session_id, sizeof(session_id)))
return 0;
/* Check cookie */
if (!PACKET_get_length_prefixed_1(&pkt, &pkt2))
return 0;
if (PACKET_remaining(&pkt2)) {
if (!PACKET_equal(&pkt2, cookie, sizeof(cookie)))
return 0;
cookie_found = 1;
}
/* Skip ciphers */
if (!PACKET_get_net_2(&pkt, &u) || !PACKET_forward(&pkt, u))
return 0;
/* Skip compression */
if (!PACKET_get_1(&pkt, &u) || !PACKET_forward(&pkt, u))
return 0;
/* Skip extensions */
if (!PACKET_get_net_2(&pkt, &u) || !PACKET_forward(&pkt, u))
return 0;
/* Now we are at the end */
if (PACKET_remaining(&pkt))
return 0;
/* Update handshake MAC for second ClientHello (with cookie) */
if (cookie_found && (!EVP_DigestUpdate(&handshake_md5, data + MAC_OFFSET,
len - MAC_OFFSET) ||
!EVP_DigestUpdate(&handshake_sha1, data + MAC_OFFSET,
len - MAC_OFFSET)))
printf("EVP_DigestUpdate() failed\n");
(void)BIO_reset(wbio);
return 1 + cookie_found;
}
static int send_hello_verify(BIO *rbio)
{
static unsigned char hello_verify[] = {
0x16, /* Handshake */
0x01, 0x00, /* DTLS1_BAD_VER */
0x00, 0x00, /* Epoch 0 */
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, /* Seq# 0 */
0x00, 0x23, /* Length */
0x03, /* Hello Verify */
0x00, 0x00, 0x17, /* Length */
0x00, 0x00, /* Seq# 0 */
0x00, 0x00, 0x00, /* Fragment offset */
0x00, 0x00, 0x17, /* Fragment length */
0x01, 0x00, /* DTLS1_BAD_VER */
0x14, /* Cookie length */
#define HV_COOKIE_OFS 28 /* Cookie goes here */
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00,
};
memcpy(hello_verify + HV_COOKIE_OFS, cookie, sizeof(cookie));
BIO_write(rbio, hello_verify, sizeof(hello_verify));
return 1;
}
static int send_server_hello(BIO *rbio)
{
static unsigned char server_hello[] = {
0x16, /* Handshake */
0x01, 0x00, /* DTLS1_BAD_VER */
0x00, 0x00, /* Epoch 0 */
0x00, 0x00, 0x00, 0x00, 0x00, 0x01, /* Seq# 1 */
0x00, 0x52, /* Length */
0x02, /* Server Hello */
0x00, 0x00, 0x46, /* Length */
0x00, 0x01, /* Seq# */
0x00, 0x00, 0x00, /* Fragment offset */
0x00, 0x00, 0x46, /* Fragment length */
0x01, 0x00, /* DTLS1_BAD_VER */
#define SH_RANDOM_OFS 27 /* Server random goes here */
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
0x20, /* Session ID length */
#define SH_SESSID_OFS 60 /* Session ID goes here */
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
0x00, 0x2f, /* Cipher suite AES128-SHA */
0x00, /* Compression null */
};
static unsigned char change_cipher_spec[] = {
0x14, /* Change Cipher Spec */
0x01, 0x00, /* DTLS1_BAD_VER */
0x00, 0x00, /* Epoch 0 */
0x00, 0x00, 0x00, 0x00, 0x00, 0x02, /* Seq# 2 */
0x00, 0x03, /* Length */
0x01, 0x00, 0x02, /* Message */
};
memcpy(server_hello + SH_RANDOM_OFS, server_random, sizeof(server_random));
memcpy(server_hello + SH_SESSID_OFS, session_id, sizeof(session_id));
if (!EVP_DigestUpdate(&handshake_md5, server_hello + MAC_OFFSET,
sizeof(server_hello) - MAC_OFFSET) ||
!EVP_DigestUpdate(&handshake_sha1, server_hello + MAC_OFFSET,
sizeof(server_hello) - MAC_OFFSET))
printf("EVP_DigestUpdate() failed\n");
BIO_write(rbio, server_hello, sizeof(server_hello));
BIO_write(rbio, change_cipher_spec, sizeof(change_cipher_spec));
return 1;
}
/* Create header, HMAC, pad, encrypt and send a record */
static int send_record(BIO *rbio, unsigned char type, unsigned long seqnr,
const void *msg, size_t len)
{
/* Note that the order of the record header fields on the wire,
* and in the HMAC, is different. So we just keep them in separate
* variables and handle them individually. */
static unsigned char epoch[2] = { 0x00, 0x01 };
static unsigned char seq[6] = { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 };
static unsigned char ver[2] = { 0x01, 0x00 }; /* DTLS1_BAD_VER */
unsigned char lenbytes[2];
HMAC_CTX ctx;
EVP_CIPHER_CTX enc_ctx;
unsigned char iv[16];
unsigned char pad;
unsigned char *enc;
#ifdef SIXTY_FOUR_BIT_LONG
seq[0] = (seqnr >> 40) & 0xff;
seq[1] = (seqnr >> 32) & 0xff;
#endif
seq[2] = (seqnr >> 24) & 0xff;
seq[3] = (seqnr >> 16) & 0xff;
seq[4] = (seqnr >> 8) & 0xff;
seq[5] = seqnr & 0xff;
pad = 15 - ((len + SHA_DIGEST_LENGTH) % 16);
enc = OPENSSL_malloc(len + SHA_DIGEST_LENGTH + 1 + pad);
if (enc == NULL)
return 0;
/* Copy record to encryption buffer */
memcpy(enc, msg, len);
/* Append HMAC to data */
HMAC_Init(&ctx, mac_key, 20, EVP_sha1());
HMAC_Update(&ctx, epoch, 2);
HMAC_Update(&ctx, seq, 6);
HMAC_Update(&ctx, &type, 1);
HMAC_Update(&ctx, ver, 2); /* Version */
lenbytes[0] = len >> 8;
lenbytes[1] = len & 0xff;
HMAC_Update(&ctx, lenbytes, 2); /* Length */
HMAC_Update(&ctx, enc, len); /* Finally the data itself */
HMAC_Final(&ctx, enc + len, NULL);
HMAC_CTX_cleanup(&ctx);
/* Append padding bytes */
len += SHA_DIGEST_LENGTH;
do {
enc[len++] = pad;
} while (len % 16);
/* Generate IV, and encrypt */
RAND_bytes(iv, sizeof(iv));
EVP_CIPHER_CTX_init(&enc_ctx);
EVP_CipherInit_ex(&enc_ctx, EVP_aes_128_cbc(), NULL, enc_key, iv, 1);
EVP_Cipher(&enc_ctx, enc, enc, len);
EVP_CIPHER_CTX_cleanup(&enc_ctx);
/* Finally write header (from fragmented variables), IV and encrypted record */
BIO_write(rbio, &type, 1);
BIO_write(rbio, ver, 2);
BIO_write(rbio, epoch, 2);
BIO_write(rbio, seq, 6);
lenbytes[0] = (len + sizeof(iv)) >> 8;
lenbytes[1] = (len + sizeof(iv)) & 0xff;
BIO_write(rbio, lenbytes, 2);
BIO_write(rbio, iv, sizeof(iv));
BIO_write(rbio, enc, len);
OPENSSL_free(enc);
return 1;
}
static int send_finished(SSL *s, BIO *rbio)
{
static unsigned char finished_msg[DTLS1_HM_HEADER_LENGTH +
TLS1_FINISH_MAC_LENGTH] = {
0x14, /* Finished */
0x00, 0x00, 0x0c, /* Length */
0x00, 0x03, /* Seq# 3 */
0x00, 0x00, 0x00, /* Fragment offset */
0x00, 0x00, 0x0c, /* Fragment length */
/* Finished MAC (12 bytes) */
};
unsigned char handshake_hash[EVP_MAX_MD_SIZE * 2];
/* Derive key material */
do_PRF(TLS_MD_KEY_EXPANSION_CONST, TLS_MD_KEY_EXPANSION_CONST_SIZE,
server_random, SSL3_RANDOM_SIZE,
client_random, SSL3_RANDOM_SIZE,
key_block, sizeof(key_block));
/* Generate Finished MAC */
if (!EVP_DigestFinal_ex(&handshake_md5, handshake_hash, NULL) ||
!EVP_DigestFinal_ex(&handshake_sha1, handshake_hash + EVP_MD_CTX_size(&handshake_md5), NULL))
printf("EVP_DigestFinal_ex() failed\n");
do_PRF(TLS_MD_SERVER_FINISH_CONST, TLS_MD_SERVER_FINISH_CONST_SIZE,
handshake_hash, EVP_MD_CTX_size(&handshake_md5) + EVP_MD_CTX_size(&handshake_sha1),
NULL, 0,
finished_msg + DTLS1_HM_HEADER_LENGTH, TLS1_FINISH_MAC_LENGTH);
return send_record(rbio, SSL3_RT_HANDSHAKE, 0,
finished_msg, sizeof(finished_msg));
}
static int validate_ccs(BIO *wbio)
{
PACKET pkt;
long len;
unsigned char *data;
unsigned int u;
len = BIO_get_mem_data(wbio, (char **)&data);
if (!PACKET_buf_init(&pkt, data, len))
return 0;
/* Check record header type */
if (!PACKET_get_1(&pkt, &u) || u != SSL3_RT_CHANGE_CIPHER_SPEC)
return 0;
/* Version */
if (!PACKET_get_net_2(&pkt, &u) || u != DTLS1_BAD_VER)
return 0;
/* Skip the rest of the record header */
if (!PACKET_forward(&pkt, DTLS1_RT_HEADER_LENGTH - 3))
return 0;
/* Check ChangeCipherSpec message */
if (!PACKET_get_1(&pkt, &u) || u != SSL3_MT_CCS)
return 0;
/* A DTLS1_BAD_VER ChangeCipherSpec also contains the
* handshake sequence number (which is 2 here) */
if (!PACKET_get_net_2(&pkt, &u) || u != 0x0002)
return 0;
/* Now check the Finished packet */
if (!PACKET_get_1(&pkt, &u) || u != SSL3_RT_HANDSHAKE)
return 0;
if (!PACKET_get_net_2(&pkt, &u) || u != DTLS1_BAD_VER)
return 0;
/* Check epoch is now 1 */
if (!PACKET_get_net_2(&pkt, &u) || u != 0x0001)
return 0;
/* That'll do for now. If OpenSSL accepted *our* Finished packet
* then it's evidently remembered that DTLS1_BAD_VER doesn't
* include the handshake header in the MAC. There's not a lot of
* point in implementing decryption here, just to check that it
* continues to get it right for one more packet. */
return 1;
}
#define NODROP(x) { x##UL, 0 }
#define DROP(x) { x##UL, 1 }
static struct {
unsigned long seq;
int drop;
} tests[] = {
NODROP(1), NODROP(3), NODROP(2),
NODROP(0x1234), NODROP(0x1230), NODROP(0x1235),
NODROP(0xffff), NODROP(0x10001), NODROP(0xfffe), NODROP(0x10000),
DROP(0x10001), DROP(0xff), NODROP(0x100000), NODROP(0x800000), NODROP(0x7fffe1),
NODROP(0xffffff), NODROP(0x1000000), NODROP(0xfffffe), DROP(0xffffff), NODROP(0x1000010),
NODROP(0xfffffd), NODROP(0x1000011), DROP(0x12), NODROP(0x1000012),
NODROP(0x1ffffff), NODROP(0x2000000), DROP(0x1ff00fe), NODROP(0x2000001),
NODROP(0x20fffff), NODROP(0x2105500), DROP(0x20ffffe), NODROP(0x21054ff),
NODROP(0x211ffff), DROP(0x2110000), NODROP(0x2120000)
/* The last test should be NODROP, because a DROP wouldn't get tested. */
};
int main(int argc, char *argv[])
{
SSL_SESSION *sess;
SSL_CTX *ctx;
SSL *con;
BIO *rbio;
BIO *wbio;
BIO *err;
int testresult = 0;
int ret;
int i;
SSL_library_init();
SSL_load_error_strings();
err = BIO_new_fp(stderr, BIO_NOCLOSE | BIO_FP_TEXT);
CRYPTO_malloc_debug_init();
CRYPTO_set_mem_debug_options(V_CRYPTO_MDEBUG_ALL);
CRYPTO_mem_ctrl(CRYPTO_MEM_CHECK_ON);
RAND_bytes(session_id, sizeof(session_id));
RAND_bytes(master_secret, sizeof(master_secret));
RAND_bytes(cookie, sizeof(cookie));
RAND_bytes(server_random + 4, sizeof(server_random) - 4);
time((void *)server_random);
sess = client_session();
if (sess == NULL) {
printf("Failed to generate SSL_SESSION\n");
goto end;
}
if (!EVP_DigestInit_ex(&handshake_md5, EVP_md5(), NULL) ||
!EVP_DigestInit_ex(&handshake_sha1, EVP_sha1(), NULL)) {
printf("Failed to initialise handshake_md\n");
goto end;
}
ctx = SSL_CTX_new(DTLSv1_client_method());
if (ctx == NULL) {
printf("Failed to allocate SSL_CTX\n");
goto end_md;
}
SSL_CTX_set_options(ctx, SSL_OP_CISCO_ANYCONNECT);
if (!SSL_CTX_set_cipher_list(ctx, "AES128-SHA")) {
printf("SSL_CTX_set_cipher_list() failed\n");
goto end_ctx;
}
con = SSL_new(ctx);
if (!SSL_set_session(con, sess)) {
printf("SSL_set_session() failed\n");
goto end_con;
}
SSL_SESSION_free(sess);
rbio = BIO_new(BIO_s_mem());
wbio = BIO_new(BIO_s_mem());
BIO_set_nbio(rbio, 1);
BIO_set_nbio(wbio, 1);
SSL_set_bio(con, rbio, wbio);
SSL_set_connect_state(con);
/* Send initial ClientHello */
ret = SSL_do_handshake(con);
if (ret > 0 || SSL_get_error(con, ret) != SSL_ERROR_WANT_READ) {
printf("Unexpected handshake result at initial call!\n");
goto end_con;
}
if (validate_client_hello(wbio) != 1) {
printf("Initial ClientHello failed validation\n");
goto end_con;
}
if (send_hello_verify(rbio) != 1) {
printf("Failed to send HelloVerify\n");
goto end_con;
}
ret = SSL_do_handshake(con);
if (ret > 0 || SSL_get_error(con, ret) != SSL_ERROR_WANT_READ) {
printf("Unexpected handshake result after HelloVerify!\n");
goto end_con;
}
if (validate_client_hello(wbio) != 2) {
printf("Second ClientHello failed validation\n");
goto end_con;
}
if (send_server_hello(rbio) != 1) {
printf("Failed to send ServerHello\n");
goto end_con;
}
ret = SSL_do_handshake(con);
if (ret > 0 || SSL_get_error(con, ret) != SSL_ERROR_WANT_READ) {
printf("Unexpected handshake result after ServerHello!\n");
goto end_con;
}
if (send_finished(con, rbio) != 1) {
printf("Failed to send Finished\n");
goto end_con;
}
ret = SSL_do_handshake(con);
if (ret < 1) {
printf("Handshake not successful after Finished!\n");
goto end_con;
}
if (validate_ccs(wbio) != 1) {
printf("Failed to validate client CCS/Finished\n");
goto end_con;
}
/* While we're here and crafting packets by hand, we might as well do a
bit of a stress test on the DTLS record replay handling. Not Cisco-DTLS
specific but useful anyway for the general case. It's been broken
before, and in fact was broken even for a basic 0, 2, 1 test case
when this test was first added.... */
for (i = 0; i < (int)OSSL_NELEM(tests); i++) {
unsigned long recv_buf[2];
if (send_record(rbio, SSL3_RT_APPLICATION_DATA, tests[i].seq,
&tests[i].seq, sizeof(unsigned long)) != 1) {
printf("Failed to send data seq #0x%lx (%d)\n",
tests[i].seq, i);
goto end_con;
}
if (tests[i].drop)
continue;
ret = SSL_read(con, recv_buf, 2 * sizeof(unsigned long));
if (ret != sizeof(unsigned long)) {
printf("SSL_read failed or wrong size on seq#0x%lx (%d)\n",
tests[i].seq, i);
goto end_con;
}
if (recv_buf[0] != tests[i].seq) {
printf("Wrong data packet received (0x%lx not 0x%lx) at packet %d\n",
recv_buf[0], tests[i].seq, i);
goto end_con;
}
}
if (tests[i-1].drop) {
printf("Error: last test cannot be DROP()\n");
goto end_con;
}
testresult=1;
end_con:
SSL_free(con);
end_ctx:
SSL_CTX_free(ctx);
end_md:
EVP_MD_CTX_cleanup(&handshake_md5);
EVP_MD_CTX_cleanup(&handshake_sha1);
end:
ERR_print_errors_fp(stderr);
if (!testresult) {
printf("Cisco BadDTLS test: FAILED\n");
}
ERR_free_strings();
ERR_remove_thread_state(NULL);
EVP_cleanup();
CRYPTO_cleanup_all_ex_data();
CRYPTO_mem_leaks(err);
BIO_free(err);
return testresult?0:1;
}
