diff options
Diffstat (limited to 'networking')
| -rw-r--r-- | networking/tls.c | 413 |
1 files changed, 248 insertions, 165 deletions
diff --git a/networking/tls.c b/networking/tls.c index 8549a21da..a65da4ad4 100644 --- a/networking/tls.c +++ b/networking/tls.c @@ -18,10 +18,50 @@ #include "tls.h" -#define TLS_DEBUG 0 -#define TLS_DEBUG_HASH 0 -#define TLS_DEBUG_DER 0 -#define TLS_DEBUG_FIXED_SECRETS 0 +//Tested against kernel.org: +//TLS 1.2 +#define TLS_MAJ 3 +#define TLS_MIN 3 +//#define CIPHER_ID TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA // ok, recvs SERVER_KEY_EXCHANGE *** matrixssl uses this on my box +//#define CIPHER_ID TLS_RSA_WITH_AES_256_CBC_SHA256 // ok, no SERVER_KEY_EXCHANGE +//#define CIPHER_ID TLS_DH_anon_WITH_AES_256_CBC_SHA // SSL_ALERT_HANDSHAKE_FAILURE +//^^^^^^^^^^^^^^^^^^^^^^^ (tested b/c this one doesn't req server certs... no luck, server refuses it) +//#define CIPHER_ID TLS_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384 // SSL_ALERT_HANDSHAKE_FAILURE +//#define CIPHER_ID TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256 // SSL_ALERT_HANDSHAKE_FAILURE +//#define CIPHER_ID TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 // ok, recvs SERVER_KEY_EXCHANGE +//#define CIPHER_ID TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256 +//#define CIPHER_ID TLS_ECDH_ECDSA_WITH_AES_256_GCM_SHA384 +//#define CIPHER_ID TLS_ECDH_ECDSA_WITH_AES_128_GCM_SHA256 // SSL_ALERT_HANDSHAKE_FAILURE +//#define CIPHER_ID TLS_ECDH_RSA_WITH_AES_256_GCM_SHA384 +//#define CIPHER_ID TLS_ECDH_RSA_WITH_AES_128_GCM_SHA256 // SSL_ALERT_HANDSHAKE_FAILURE +//#define CIPHER_ID TLS_RSA_WITH_AES_256_GCM_SHA384 // ok, no SERVER_KEY_EXCHANGE +//#define CIPHER_ID TLS_RSA_WITH_AES_128_GCM_SHA256 // ok, no SERVER_KEY_EXCHANGE *** select this? + +// works against "openssl s_server -cipher NULL" +// and against wolfssl-3.9.10-stable/examples/server/server.c: +//#define CIPHER_ID TLS_RSA_WITH_NULL_SHA256 // for testing (does everything except encrypting) + +// works against wolfssl-3.9.10-stable/examples/server/server.c +// works for kernel.org +// does not work for cdn.kernel.org (e.g. downloading an actual tarball, not a web page) +// getting alert 40 "handshake failure" at once +// with GNU Wget 1.18, they agree on TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256 (0xC02F) cipher +// fail: openssl s_client -connect cdn.kernel.org:443 -debug -tls1_2 -no_tls1 -no_tls1_1 -cipher AES256-SHA256 +// fail: openssl s_client -connect cdn.kernel.org:443 -debug -tls1_2 -no_tls1 -no_tls1_1 -cipher AES256-GCM-SHA384 +// fail: openssl s_client -connect cdn.kernel.org:443 -debug -tls1_2 -no_tls1 -no_tls1_1 -cipher AES128-SHA256 +// ok: openssl s_client -connect cdn.kernel.org:443 -debug -tls1_2 -no_tls1 -no_tls1_1 -cipher AES128-GCM-SHA256 +// ok: openssl s_client -connect cdn.kernel.org:443 -debug -tls1_2 -no_tls1 -no_tls1_1 -cipher AES128-SHA +// (TLS_RSA_WITH_AES_128_CBC_SHA - in TLS 1.2 it's mandated to be always supported) +#define CIPHER_ID1 TLS_RSA_WITH_AES_256_CBC_SHA256 // no SERVER_KEY_EXCHANGE from peer +// Does not work yet: +//#define CIPHER_ID2 TLS_RSA_WITH_AES_128_CBC_SHA +#define CIPHER_ID2 0 + + +#define TLS_DEBUG 1 +#define TLS_DEBUG_HASH 1 +#define TLS_DEBUG_DER 1 +#define TLS_DEBUG_FIXED_SECRETS 1 #if 0 # define dump_raw_out(...) dump_hex(__VA_ARGS__) #else @@ -124,52 +164,26 @@ #define TLS_ECDH_RSA_WITH_AES_128_GCM_SHA256 0xC031 /* 49201 */ #define TLS_ECDH_RSA_WITH_AES_256_GCM_SHA384 0xC032 /* 49202 */ -//Tested against kernel.org: -//TLS 1.2 -#define TLS_MAJ 3 -#define TLS_MIN 3 -//#define CIPHER_ID TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA // ok, recvs SERVER_KEY_EXCHANGE *** matrixssl uses this on my box -//#define CIPHER_ID TLS_RSA_WITH_AES_256_CBC_SHA256 // ok, no SERVER_KEY_EXCHANGE -//#define CIPHER_ID TLS_DH_anon_WITH_AES_256_CBC_SHA // SSL_ALERT_HANDSHAKE_FAILURE -//^^^^^^^^^^^^^^^^^^^^^^^ (tested b/c this one doesn't req server certs... no luck, server refuses it) -//#define CIPHER_ID TLS_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384 // SSL_ALERT_HANDSHAKE_FAILURE -//#define CIPHER_ID TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256 // SSL_ALERT_HANDSHAKE_FAILURE -//#define CIPHER_ID TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 // ok, recvs SERVER_KEY_EXCHANGE -//#define CIPHER_ID TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256 -//#define CIPHER_ID TLS_ECDH_ECDSA_WITH_AES_256_GCM_SHA384 -//#define CIPHER_ID TLS_ECDH_ECDSA_WITH_AES_128_GCM_SHA256 // SSL_ALERT_HANDSHAKE_FAILURE -//#define CIPHER_ID TLS_ECDH_RSA_WITH_AES_256_GCM_SHA384 -//#define CIPHER_ID TLS_ECDH_RSA_WITH_AES_128_GCM_SHA256 // SSL_ALERT_HANDSHAKE_FAILURE -//#define CIPHER_ID TLS_RSA_WITH_AES_256_GCM_SHA384 // ok, no SERVER_KEY_EXCHANGE -//#define CIPHER_ID TLS_RSA_WITH_AES_128_GCM_SHA256 // ok, no SERVER_KEY_EXCHANGE *** select this? +/* Might go to libbb.h */ +#define TLS_MAX_CRYPTBLOCK_SIZE 16 +#define TLS_MAX_OUTBUF (1 << 14) -// works against "openssl s_server -cipher NULL" -// and against wolfssl-3.9.10-stable/examples/server/server.c: -//#define CIPHER_ID TLS_RSA_WITH_NULL_SHA256 // for testing (does everything except encrypting) +enum { + SHA_INSIZE = 64, + SHA1_OUTSIZE = 20, + SHA256_OUTSIZE = 32, -// works against wolfssl-3.9.10-stable/examples/server/server.c -// works for kernel.org -// does not work for cdn.kernel.org (e.g. downloading an actual tarball, not a web page) -// getting alert 40 "handshake failure" at once -// with GNU Wget 1.18, they agree on TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256 (0xC02F) cipher -// fail: openssl s_client -connect cdn.kernel.org:443 -debug -tls1_2 -no_tls1 -no_tls1_1 -cipher AES256-SHA256 -// fail: openssl s_client -connect cdn.kernel.org:443 -debug -tls1_2 -no_tls1 -no_tls1_1 -cipher AES256-GCM-SHA384 -// fail: openssl s_client -connect cdn.kernel.org:443 -debug -tls1_2 -no_tls1 -no_tls1_1 -cipher AES128-SHA256 -// ok: openssl s_client -connect cdn.kernel.org:443 -debug -tls1_2 -no_tls1 -no_tls1_1 -cipher AES128-GCM-SHA256 -// ok: openssl s_client -connect cdn.kernel.org:443 -debug -tls1_2 -no_tls1 -no_tls1_1 -cipher AES128-SHA -// (TLS_RSA_WITH_AES_128_CBC_SHA - in TLS 1.2 it's mandated to be always supported) -#define CIPHER_ID TLS_RSA_WITH_AES_256_CBC_SHA256 // no SERVER_KEY_EXCHANGE from peer + AES_BLOCKSIZE = 16, + AES128_KEYSIZE = 16, + AES256_KEYSIZE = 32, -enum { RSA_PREMASTER_SIZE = 48, RECHDR_LEN = 5, - MAX_TLS_RECORD = (1 << 14), /* 8 = 3+5. 3 extra bytes result in record data being 32-bit aligned */ OUTBUF_PFX = 8 + AES_BLOCKSIZE, /* header + IV */ - OUTBUF_SFX = SHA256_OUTSIZE + AES_BLOCKSIZE, /* MAC + padding */ - MAX_OUTBUF = MAX_TLS_RECORD - OUTBUF_PFX - OUTBUF_SFX, + OUTBUF_SFX = TLS_MAX_MAC_SIZE + TLS_MAX_CRYPTBLOCK_SIZE, /* MAC + padding */ // RFC 5246 // | 6.2.1. Fragmentation @@ -205,7 +219,7 @@ enum { // | length // | The length (in bytes) of the following TLSCiphertext.fragment. // | The length MUST NOT exceed 2^14 + 2048. - MAX_INBUF = (1 << 14) + 2048, + MAX_INBUF = RECHDR_LEN + (1 << 14) + 2048, }; struct record_hdr { @@ -215,12 +229,17 @@ struct record_hdr { }; struct tls_handshake_data { - sha256_ctx_t handshake_sha256_ctx; + /* In bbox, md5/sha1/sha256 ctx's are the same structure */ + md5sha_ctx_t handshake_hash_ctx; + uint8_t client_and_server_rand32[2 * 32]; uint8_t master_secret[48]; //TODO: store just the DER key here, parse/use/delete it when sending client key //this way it will stay key type agnostic here. psRsaKey_t server_rsa_pub_key; + + unsigned saved_client_hello_size; + uint8_t saved_client_hello[1]; }; @@ -275,37 +294,41 @@ void tls_get_random(void *buf, unsigned len) xfunc_die(); } -//TODO rename this to sha256_hash, and sha256_hash -> sha256_update -static void hash_sha256(uint8_t out[SHA256_OUTSIZE], const void *data, unsigned size) +/* Nondestructively see the current hash value */ +static unsigned sha_peek(md5sha_ctx_t *ctx, void *buffer) { - sha256_ctx_t ctx; - sha256_begin(&ctx); - sha256_hash(&ctx, data, size); - sha256_end(&ctx, out); + md5sha_ctx_t ctx_copy = *ctx; /* struct copy */ + return sha_end(&ctx_copy, buffer); } -/* Nondestructively see the current hash value */ -static void sha256_peek(sha256_ctx_t *ctx, void *buffer) +static ALWAYS_INLINE unsigned get_handshake_hash(tls_state_t *tls, void *buffer) { - sha256_ctx_t ctx_copy = *ctx; - sha256_end(&ctx_copy, buffer); + return sha_peek(&tls->hsd->handshake_hash_ctx, buffer); } -#if TLS_DEBUG_HASH -static void sha256_hash_dbg(const char *fmt, sha256_ctx_t *ctx, const void *buffer, size_t len) +#if !TLS_DEBUG_HASH +# define hash_handshake(tls, fmt, buffer, len) \ + hash_handshake(tls, buffer, len) +#endif +static void hash_handshake(tls_state_t *tls, const char *fmt, const void *buffer, unsigned len) { - uint8_t h[SHA256_OUTSIZE]; - - sha256_hash(ctx, buffer, len); - dump_hex(fmt, buffer, len); - dbg(" (%u) ", (int)len); - sha256_peek(ctx, h); - dump_hex("%s\n", h, SHA256_OUTSIZE); -} -#else -# define sha256_hash_dbg(fmt, ctx, buffer, len) \ - sha256_hash(ctx, buffer, len) + md5sha_hash(&tls->hsd->handshake_hash_ctx, buffer, len); +#if TLS_DEBUG_HASH + { + uint8_t h[TLS_MAX_MAC_SIZE]; + dump_hex(fmt, buffer, len); + dbg(" (%u bytes) ", (int)len); + len = sha_peek(&tls->hsd->handshake_hash_ctx, h); + if (len == SHA1_OUTSIZE) + dump_hex("sha1:%s\n", h, len); + else + if (len == SHA256_OUTSIZE) + dump_hex("sha256:%s\n", h, len); + else + dump_hex("sha???:%s\n", h, len); + } #endif +} // RFC 2104 // HMAC(key, text) based on a hash H (say, sha256) is: @@ -317,12 +340,13 @@ static void sha256_hash_dbg(const char *fmt, sha256_ctx_t *ctx, const void *buff // if we often need HMAC hmac with the same key. // // text is often given in disjoint pieces. -static void hmac_sha256_precomputed_v(uint8_t out[SHA256_OUTSIZE], - sha256_ctx_t *hashed_key_xor_ipad, - sha256_ctx_t *hashed_key_xor_opad, +static unsigned hmac_sha_precomputed_v(uint8_t *out, + md5sha_ctx_t *hashed_key_xor_ipad, + md5sha_ctx_t *hashed_key_xor_opad, va_list va) { uint8_t *text; + unsigned len; /* hashed_key_xor_ipad contains unclosed "H((key XOR ipad) +" state */ /* hashed_key_xor_opad contains unclosed "H((key XOR opad) +" state */ @@ -330,24 +354,24 @@ static void hmac_sha256_precomputed_v(uint8_t out[SHA256_OUTSIZE], /* calculate out = H((key XOR ipad) + text) */ while ((text = va_arg(va, uint8_t*)) != NULL) { unsigned text_size = va_arg(va, unsigned); - sha256_hash(hashed_key_xor_ipad, text, text_size); + md5sha_hash(hashed_key_xor_ipad, text, text_size); } - sha256_end(hashed_key_xor_ipad, out); + len = sha_end(hashed_key_xor_ipad, out); /* out = H((key XOR opad) + out) */ - sha256_hash(hashed_key_xor_opad, out, SHA256_OUTSIZE); - sha256_end(hashed_key_xor_opad, out); + md5sha_hash(hashed_key_xor_opad, out, len); + return sha_end(hashed_key_xor_opad, out); } -static void hmac_sha256(uint8_t out[SHA256_OUTSIZE], uint8_t *key, unsigned key_size, ...) +static unsigned hmac(tls_state_t *tls, uint8_t *out, uint8_t *key, unsigned key_size, ...) { - sha256_ctx_t hashed_key_xor_ipad; - sha256_ctx_t hashed_key_xor_opad; - uint8_t key_xor_ipad[SHA256_INSIZE]; - uint8_t key_xor_opad[SHA256_INSIZE]; + md5sha_ctx_t hashed_key_xor_ipad; + md5sha_ctx_t hashed_key_xor_opad; + uint8_t key_xor_ipad[SHA_INSIZE]; + uint8_t key_xor_opad[SHA_INSIZE]; uint8_t tempkey[SHA256_OUTSIZE]; va_list va; - int i; + unsigned i; va_start(va, key_size); @@ -355,27 +379,38 @@ static void hmac_sha256(uint8_t out[SHA256_OUTSIZE], uint8_t *key, unsigned key_ // block length of the hash function. Applications that use keys longer // than INSIZE bytes will first hash the key using H and then use the // resultant OUTSIZE byte string as the actual key to HMAC." - if (key_size > SHA256_INSIZE) { - hash_sha256(tempkey, key, key_size); - key = tempkey; - key_size = SHA256_OUTSIZE; + if (key_size > SHA_INSIZE) { + md5sha_ctx_t ctx; + if (tls->MAC_size == SHA256_OUTSIZE) + sha256_begin(&ctx); + else + sha1_begin(&ctx); + md5sha_hash(&ctx, key, key_size); + key_size = sha_end(&ctx, tempkey); } for (i = 0; i < key_size; i++) { key_xor_ipad[i] = key[i] ^ 0x36; key_xor_opad[i] = key[i] ^ 0x5c; } - for (; i < SHA256_INSIZE; i++) { + for (; i < SHA_INSIZE; i++) { key_xor_ipad[i] = 0x36; key_xor_opad[i] = 0x5c; } - sha256_begin(&hashed_key_xor_ipad); - sha256_hash(&hashed_key_xor_ipad, key_xor_ipad, SHA256_INSIZE); - sha256_begin(&hashed_key_xor_opad); - sha256_hash(&hashed_key_xor_opad, key_xor_opad, SHA256_INSIZE); - hmac_sha256_precomputed_v(out, &hashed_key_xor_ipad, &hashed_key_xor_opad, va); + if (tls->MAC_size == SHA256_OUTSIZE) { + sha256_begin(&hashed_key_xor_ipad); + sha256_begin(&hashed_key_xor_opad); + } else { + sha1_begin(&hashed_key_xor_ipad); + sha1_begin(&hashed_key_xor_opad); + } + md5sha_hash(&hashed_key_xor_ipad, key_xor_ipad, SHA_INSIZE); + md5sha_hash(&hashed_key_xor_opad, key_xor_opad, SHA_INSIZE); + + i = hmac_sha_precomputed_v(out, &hashed_key_xor_ipad, &hashed_key_xor_opad, va); va_end(va); + return i; } // RFC 5246: @@ -406,40 +441,41 @@ static void hmac_sha256(uint8_t out[SHA256_OUTSIZE], uint8_t *key, unsigned key_ // PRF(secret, label, seed) = P_<hash>(secret, label + seed) // // The label is an ASCII string. -static void prf_hmac_sha256( +static void prf_hmac(tls_state_t *tls, uint8_t *outbuf, unsigned outbuf_size, uint8_t *secret, unsigned secret_size, const char *label, uint8_t *seed, unsigned seed_size) { - uint8_t a[SHA256_OUTSIZE]; + uint8_t a[TLS_MAX_MAC_SIZE]; uint8_t *out_p = outbuf; unsigned label_size = strlen(label); + unsigned MAC_size = tls->MAC_size; /* In P_hash() calculation, "seed" is "label + seed": */ #define SEED label, label_size, seed, seed_size #define SECRET secret, secret_size -#define A a, (int)(sizeof(a)) +#define A a, MAC_size /* A(1) = HMAC_hash(secret, seed) */ - hmac_sha256(a, SECRET, SEED, NULL); -//TODO: convert hmac_sha256 to precomputed + hmac(tls, a, SECRET, SEED, NULL); +//TODO: convert hmac to precomputed for(;;) { /* HMAC_hash(secret, A(1) + seed) */ - if (outbuf_size <= SHA256_OUTSIZE) { + if (outbuf_size <= MAC_size) { /* Last, possibly incomplete, block */ /* (use a[] as temp buffer) */ - hmac_sha256(a, SECRET, A, SEED, NULL); + hmac(tls, a, SECRET, A, SEED, NULL); memcpy(out_p, a, outbuf_size); return; } /* Not last block. Store directly to result buffer */ - hmac_sha256(out_p, SECRET, A, SEED, NULL); - out_p += SHA256_OUTSIZE; - outbuf_size -= SHA256_OUTSIZE; + hmac(tls, out_p, SECRET, A, SEED, NULL); + out_p += MAC_size; + outbuf_size -= MAC_size; /* A(2) = HMAC_hash(secret, A(1)) */ - hmac_sha256(a, SECRET, A, NULL); + hmac(tls, a, SECRET, A, NULL); } #undef A #undef SECRET @@ -484,11 +520,12 @@ static void tls_free_outbuf(tls_state_t *tls) static void *tls_get_outbuf(tls_state_t *tls, int len) { - if (len > MAX_OUTBUF) + if (len > TLS_MAX_OUTBUF) xfunc_die(); - if (tls->outbuf_size < len + OUTBUF_PFX + OUTBUF_SFX) { - tls->outbuf_size = len + OUTBUF_PFX + OUTBUF_SFX; - tls->outbuf = xrealloc(tls->outbuf, tls->outbuf_size); + len += OUTBUF_PFX + OUTBUF_SFX; + if (tls->outbuf_size < len) { + tls->outbuf_size = len; + tls->outbuf = xrealloc(tls->outbuf, len); } return tls->outbuf + OUTBUF_PFX; } @@ -500,7 +537,7 @@ static void xwrite_encrypted(tls_state_t *tls, unsigned size, unsigned type) uint8_t padding_length; xhdr = (void*)(buf - RECHDR_LEN); - if (CIPHER_ID != TLS_RSA_WITH_NULL_SHA256) + if (tls->cipher_id != TLS_RSA_WITH_NULL_SHA256) xhdr = (void*)(buf - RECHDR_LEN - AES_BLOCKSIZE); /* place for IV */ xhdr->type = type; @@ -511,16 +548,16 @@ static void xwrite_encrypted(tls_state_t *tls, unsigned size, unsigned type) xhdr->len16_lo = size & 0xff; /* Calculate MAC signature */ -//TODO: convert hmac_sha256 to precomputed - hmac_sha256(buf + size, - tls->client_write_MAC_key, sizeof(tls->client_write_MAC_key), - &tls->write_seq64_be, sizeof(tls->write_seq64_be), - xhdr, RECHDR_LEN, - buf, size, - NULL); + hmac(tls, buf + size, /* result */ + tls->client_write_MAC_key, tls->MAC_size, + &tls->write_seq64_be, sizeof(tls->write_seq64_be), + xhdr, RECHDR_LEN, + buf, size, + NULL + ); tls->write_seq64_be = SWAP_BE64(1 + SWAP_BE64(tls->write_seq64_be)); - size += SHA256_OUTSIZE; + size += tls->MAC_size; // RFC 5246 // 6.2.3.1. Null or Standard Stream Cipher @@ -555,7 +592,7 @@ static void xwrite_encrypted(tls_state_t *tls, unsigned size, unsigned type) // -------- ----------- ---------- -------------- // SHA HMAC-SHA1 20 20 // SHA256 HMAC-SHA256 32 32 - if (CIPHER_ID == TLS_RSA_WITH_NULL_SHA256) { + if (tls->cipher_id == TLS_RSA_WITH_NULL_SHA256) { /* No encryption, only signing */ xhdr->len16_hi = size >> 8; xhdr->len16_lo = size & 0xff; @@ -603,7 +640,7 @@ static void xwrite_encrypted(tls_state_t *tls, unsigned size, unsigned type) /* Fill IV and padding in outbuf */ tls_get_random(buf - AES_BLOCKSIZE, AES_BLOCKSIZE); /* IV */ - dbg("before crypt: 5 hdr + %u data + %u hash bytes\n", size, SHA256_OUTSIZE); + dbg("before crypt: 5 hdr + %u data + %u hash bytes\n", size, tls->MAC_size); // RFC is talking nonsense: // "Padding that is added to force the length of the plaintext to be // an integral multiple of the block cipher's block length." @@ -628,7 +665,7 @@ static void xwrite_encrypted(tls_state_t *tls, unsigned size, unsigned type) { psCipherContext_t ctx; psAesInit(&ctx, buf - AES_BLOCKSIZE, /* IV */ - tls->client_write_key, sizeof(tls->client_write_key) + tls->client_write_key, tls->key_size /* selects 128/256 */ ); psAesEncrypt(&ctx, buf, /* plaintext */ @@ -648,9 +685,9 @@ static void xwrite_encrypted(tls_state_t *tls, unsigned size, unsigned type) dbg("wrote %u bytes\n", (int)RECHDR_LEN + size); } -static void xwrite_and_update_handshake_hash(tls_state_t *tls, unsigned size) +static void xwrite_handshake_record(tls_state_t *tls, unsigned size) { - if (!tls->encrypt_on_write) { + //if (!tls->encrypt_on_write) { uint8_t *buf = tls->outbuf + OUTBUF_PFX; struct record_hdr *xhdr = (void*)(buf - RECHDR_LEN); @@ -662,8 +699,20 @@ static void xwrite_and_update_handshake_hash(tls_state_t *tls, unsigned size) dump_raw_out(">> %s\n", xhdr, RECHDR_LEN + size); xwrite(tls->ofd, xhdr, RECHDR_LEN + size); dbg("wrote %u bytes\n", (int)RECHDR_LEN + size); + // return; + //} + //xwrite_encrypted(tls, size, RECORD_TYPE_HANDSHAKE); +} + +static void xwrite_and_update_handshake_hash(tls_state_t *tls, unsigned size) +{ + if (!tls->encrypt_on_write) { + uint8_t *buf; + + xwrite_handshake_record(tls, size); /* Handshake hash does not include record headers */ - sha256_hash_dbg(">> sha256:%s", &tls->hsd->handshake_sha256_ctx, buf, size); + buf = tls->outbuf + OUTBUF_PFX; + hash_handshake(tls, ">> hash:%s", buf, size); return; } xwrite_encrypted(tls, size, RECORD_TYPE_HANDSHAKE); @@ -765,7 +814,7 @@ static int tls_xread_record(tls_state_t *tls) sz = target - RECHDR_LEN; /* Needs to be decrypted? */ - if (tls->min_encrypted_len_on_read > SHA256_OUTSIZE) { + if (tls->min_encrypted_len_on_read > tls->MAC_size) { psCipherContext_t ctx; uint8_t *p = tls->inbuf + RECHDR_LEN; int padding_len; @@ -777,7 +826,7 @@ static int tls_xread_record(tls_state_t *tls) } /* Decrypt content+MAC+padding, moving it over IV in the process */ psAesInit(&ctx, p, /* IV */ - tls->server_write_key, sizeof(tls->server_write_key) + tls->server_write_key, tls->key_size /* selects 128/256 */ ); sz -= AES_BLOCKSIZE; /* we will overwrite IV now */ psAesDecrypt(&ctx, @@ -788,7 +837,7 @@ static int tls_xread_record(tls_state_t *tls) padding_len = p[sz - 1]; dbg("encrypted size:%u type:0x%02x padding_length:0x%02x\n", sz, p[0], padding_len); padding_len++; - sz -= SHA256_OUTSIZE + padding_len; /* drop MAC and padding */ + sz -= tls->MAC_size + padding_len; /* drop MAC and padding */ //if (sz < 0) // bb_error_msg_and_die("bad padding size:%u", padding_len); } else { @@ -834,8 +883,10 @@ static int tls_xread_record(tls_state_t *tls) /* RFC 5246 is not saying it explicitly, but sha256 hash * in our FINISHED record must include data of incoming packets too! */ - if (tls->inbuf[0] == RECORD_TYPE_HANDSHAKE) { - sha256_hash_dbg("<< sha256:%s", &tls->hsd->handshake_sha256_ctx, tls->inbuf + RECHDR_LEN, sz); + if (tls->inbuf[0] == RECORD_TYPE_HANDSHAKE + && tls->MAC_size != 0 /* do we know which hash to use? (server_hello() does not!) */ + ) { + hash_handshake(tls, "<< hash:%s", tls->inbuf + RECHDR_LEN, sz); } end: dbg("got block len:%u\n", sz); @@ -1088,7 +1139,7 @@ static ALWAYS_INLINE void fill_handshake_record_hdr(void *buf, unsigned type, un h->len24_lo = len & 0xff; } -static void send_client_hello(tls_state_t *tls, const char *sni) +static void send_client_hello_and_alloc_hsd(tls_state_t *tls, const char *sni) { struct client_hello { uint8_t type; @@ -1098,7 +1149,7 @@ static void send_client_hello(tls_state_t *tls, const char *sni) uint8_t session_id_len; /* uint8_t session_id[]; */ uint8_t cipherid_len16_hi, cipherid_len16_lo; - uint8_t cipherid[2 * 2]; /* actually variable */ + uint8_t cipherid[2 * (2 + !!CIPHER_ID2)]; /* actually variable */ uint8_t comprtypes_len; uint8_t comprtypes[1]; /* actually variable */ /* Extensions (SNI shown): @@ -1136,17 +1187,19 @@ static void send_client_hello(tls_state_t *tls, const char *sni) tls_get_random(record->rand32, sizeof(record->rand32)); if (TLS_DEBUG_FIXED_SECRETS) memset(record->rand32, 0x11, sizeof(record->rand32)); - memcpy(tls->hsd->client_and_server_rand32, record->rand32, sizeof(record->rand32)); /* record->session_id_len = 0; - already is */ /* record->cipherid_len16_hi = 0; */ - record->cipherid_len16_lo = 2 * 2; - if ((CIPHER_ID >> 8) != 0) - record->cipherid[0] = CIPHER_ID >> 8; - record->cipherid[1] = CIPHER_ID & 0xff; + record->cipherid_len16_lo = sizeof(record->cipherid); /* RFC 5746 Renegotiation Indication Extension - some servers will refuse to work with us otherwise */ - /*record->cipherid[2] = TLS_EMPTY_RENEGOTIATION_INFO_SCSV >> 8; - zero */ - record->cipherid[3] = TLS_EMPTY_RENEGOTIATION_INFO_SCSV & 0xff; + /*record->cipherid[0] = TLS_EMPTY_RENEGOTIATION_INFO_SCSV >> 8; - zero */ + record->cipherid[1] = TLS_EMPTY_RENEGOTIATION_INFO_SCSV & 0xff; + if ((CIPHER_ID1 >> 8) != 0) record->cipherid[2] = CIPHER_ID1 >> 8; + /*************************/ record->cipherid[3] = CIPHER_ID1 & 0xff; +#if CIPHER_ID2 + if ((CIPHER_ID2 >> 8) != 0) record->cipherid[4] = CIPHER_ID2 >> 8; + /*************************/ record->cipherid[5] = CIPHER_ID2 & 0xff; +#endif record->comprtypes_len = 1; /* record->comprtypes[0] = 0; */ @@ -1168,7 +1221,14 @@ static void send_client_hello(tls_state_t *tls, const char *sni) } dbg(">> CLIENT_HELLO\n"); - xwrite_and_update_handshake_hash(tls, len); + /* Can hash it only when we know which MAC hash to use */ + /*xwrite_and_update_handshake_hash(tls, len); - WRONG! */ + xwrite_handshake_record(tls, len); + + tls->hsd = xzalloc(sizeof(*tls->hsd) + len); + tls->hsd->saved_client_hello_size = len; + memcpy(tls->hsd->saved_client_hello, record, len); + memcpy(tls->hsd->client_and_server_rand32, record->rand32, sizeof(record->rand32)); } static void get_server_hello(tls_state_t *tls) @@ -1188,7 +1248,8 @@ static void get_server_hello(tls_state_t *tls) struct server_hello *hp; uint8_t *cipherid; - int len; + unsigned cipher; + int len, len24; len = tls_xread_handshake_block(tls, 74); @@ -1207,6 +1268,7 @@ static void get_server_hello(tls_state_t *tls) } cipherid = &hp->cipherid_hi; + len24 = hp->len24_lo; if (hp->session_id_len != 32) { if (hp->session_id_len != 0) tls_error_die(tls); @@ -1216,19 +1278,39 @@ static void get_server_hello(tls_state_t *tls) // may return an empty session_id to indicate that the session will // not be cached and therefore cannot be resumed." cipherid -= 32; - hp->len24_lo += 32; /* what len would be if session id would be present */ + len24 += 32; /* what len would be if session id would be present */ } - if (hp->len24_lo < 70 - || cipherid[0] != (CIPHER_ID >> 8) - || cipherid[1] != (CIPHER_ID & 0xff) - || cipherid[2] != 0 /* comprtype */ + if (len24 < 70 +// || cipherid[0] != (CIPHER_ID >> 8) +// || cipherid[1] != (CIPHER_ID & 0xff) +// || cipherid[2] != 0 /* comprtype */ ) { tls_error_die(tls); } - dbg("<< SERVER_HELLO\n"); + memcpy(tls->hsd->client_and_server_rand32 + 32, hp->rand32, sizeof(hp->rand32)); + + tls->cipher_id = cipher = 0x100 * cipherid[0] + cipherid[1]; + dbg("server chose cipher %04x\n", cipher); + + if (cipher == TLS_RSA_WITH_AES_128_CBC_SHA) { + tls->key_size = AES128_KEYSIZE; + tls->MAC_size = SHA1_OUTSIZE; + sha1_begin(&tls->hsd->handshake_hash_ctx); + } + else { /* TLS_RSA_WITH_AES_256_CBC_SHA256 */ + tls->key_size = AES256_KEYSIZE; + tls->MAC_size = SHA256_OUTSIZE; + sha256_begin(&tls->hsd->handshake_hash_ctx); + } + hash_handshake(tls, ">> client hello hash:%s", + tls->hsd->saved_client_hello, tls->hsd->saved_client_hello_size + ); + hash_handshake(tls, "<< server hello hash:%s", + tls->inbuf + RECHDR_LEN, len + ); } static void get_server_cert(tls_state_t *tls) @@ -1312,7 +1394,7 @@ static void send_client_key_exchange(tls_state_t *tls) // [0..47]; // The master secret is always exactly 48 bytes in length. The length // of the premaster secret will vary depending on key exchange method. - prf_hmac_sha256( + prf_hmac(tls, tls->hsd->master_secret, sizeof(tls->hsd->master_secret), rsa_premaster, sizeof(rsa_premaster), "master secret", @@ -1360,21 +1442,23 @@ static void send_client_key_exchange(tls_state_t *tls) memcpy(&tmp64[0] , &tls->hsd->client_and_server_rand32[32], 32); memcpy(&tmp64[32], &tls->hsd->client_and_server_rand32[0] , 32); - prf_hmac_sha256( - tls->client_write_MAC_key, 2 * (SHA256_OUTSIZE + AES256_KEYSIZE), + prf_hmac(tls, + tls->client_write_MAC_key, 2 * (tls->MAC_size + tls->key_size), // also fills: - // server_write_MAC_key[SHA256_OUTSIZE] - // client_write_key[AES256_KEYSIZE] - // server_write_key[AES256_KEYSIZE] + // server_write_MAC_key[] + // client_write_key[] + // server_write_key[] tls->hsd->master_secret, sizeof(tls->hsd->master_secret), "key expansion", tmp64, 64 ); + tls->client_write_key = tls->client_write_MAC_key + (2 * tls->MAC_size); + tls->server_write_key = tls->client_write_key + tls->key_size; dump_hex("client_write_MAC_key:%s\n", - tls->client_write_MAC_key, sizeof(tls->client_write_MAC_key) + tls->client_write_MAC_key, tls->MAC_size ); dump_hex("client_write_key:%s\n", - tls->client_write_key, sizeof(tls->client_write_key) + tls->client_write_key, tls->key_size ); } } @@ -1435,15 +1519,17 @@ static void send_client_finished(tls_state_t *tls) uint8_t prf_result[12]; }; struct finished *record = tls_get_outbuf(tls, sizeof(*record)); - uint8_t handshake_hash[SHA256_OUTSIZE]; + uint8_t handshake_hash[TLS_MAX_MAC_SIZE]; + unsigned len; fill_handshake_record_hdr(record, HANDSHAKE_FINISHED, sizeof(*record)); - sha256_peek(&tls->hsd->handshake_sha256_ctx, handshake_hash); - prf_hmac_sha256(record->prf_result, sizeof(record->prf_result), - tls->hsd->master_secret, sizeof(tls->hsd->master_secret), - "client finished", - handshake_hash, sizeof(handshake_hash) + len = get_handshake_hash(tls, handshake_hash); + prf_hmac(tls, + record->prf_result, sizeof(record->prf_result), + tls->hsd->master_secret, sizeof(tls->hsd->master_secret), + "client finished", + handshake_hash, len ); dump_hex("from secret: %s\n", tls->hsd->master_secret, sizeof(tls->hsd->master_secret)); dump_hex("from labelSeed: %s", "client finished", sizeof("client finished")-1); @@ -1475,10 +1561,7 @@ void FAST_FUNC tls_handshake(tls_state_t *tls, const char *sni) // Application Data <------> Application Data int len; - tls->hsd = xzalloc(sizeof(*tls->hsd)); - sha256_begin(&tls->hsd->handshake_sha256_ctx); - - send_client_hello(tls, sni); + send_client_hello_and_alloc_hsd(tls, sni); get_server_hello(tls); // RFC 5246 @@ -1535,11 +1618,11 @@ void FAST_FUNC tls_handshake(tls_state_t *tls, const char *sni) if (len != 1 || memcmp(tls->inbuf, rec_CHANGE_CIPHER_SPEC, 6) != 0) tls_error_die(tls); dbg("<< CHANGE_CIPHER_SPEC\n"); - if (CIPHER_ID == TLS_RSA_WITH_NULL_SHA256) - tls->min_encrypted_len_on_read = SHA256_OUTSIZE; + if (tls->cipher_id == TLS_RSA_WITH_NULL_SHA256) + tls->min_encrypted_len_on_read = tls->MAC_size; else /* all incoming packets now should be encrypted and have IV + MAC + padding */ - tls->min_encrypted_len_on_read = AES_BLOCKSIZE + SHA256_OUTSIZE + AES_BLOCKSIZE; + tls->min_encrypted_len_on_read = AES_BLOCKSIZE + tls->MAC_size + AES_BLOCKSIZE; /* Get (encrypted) FINISHED from the server */ len = tls_xread_record(tls); @@ -1550,7 +1633,7 @@ void FAST_FUNC tls_handshake(tls_state_t *tls, const char *sni) /* free handshake data */ // if (PARANOIA) -// memset(tls->hsd, 0, sizeof(*tls->hsd)); +// memset(tls->hsd, 0, tls->hsd->hsd_size); free(tls->hsd); tls->hsd = NULL; } @@ -1614,8 +1697,8 @@ void FAST_FUNC tls_run_copy_loop(tls_state_t *tls) * read, encrypt and send bigger chunks */ inbuf_size += INBUF_STEP; - if (inbuf_size > MAX_OUTBUF) - inbuf_size = MAX_OUTBUF; + if (inbuf_size > TLS_MAX_OUTBUF) + inbuf_size = TLS_MAX_OUTBUF; } tls_xwrite(tls, nread); } |