--- /dev/null
+/*
+ * TLSv1 Record Protocol
+ * Copyright (c) 2006-2011, Jouni Malinen <j@w1.fi>
+ *
+ * This software may be distributed under the terms of the BSD license.
+ * See README for more details.
+ */
+
+#include "includes.h"
+
+#include "common.h"
+#include "crypto/md5.h"
+#include "crypto/sha1.h"
+#include "crypto/sha256.h"
+#include "tlsv1_common.h"
+#include "tlsv1_record.h"
+
+
+/**
+ * tlsv1_record_set_cipher_suite - TLS record layer: Set cipher suite
+ * @rl: Pointer to TLS record layer data
+ * @cipher_suite: New cipher suite
+ * Returns: 0 on success, -1 on failure
+ *
+ * This function is used to prepare TLS record layer for cipher suite change.
+ * tlsv1_record_change_write_cipher() and
+ * tlsv1_record_change_read_cipher() functions can then be used to change the
+ * currently used ciphers.
+ */
+int tlsv1_record_set_cipher_suite(struct tlsv1_record_layer *rl,
+ u16 cipher_suite)
+{
+ const struct tls_cipher_suite *suite;
+ const struct tls_cipher_data *data;
+
+ wpa_printf(MSG_DEBUG, "TLSv1: Selected cipher suite: 0x%04x",
+ cipher_suite);
+ rl->cipher_suite = cipher_suite;
+
+ suite = tls_get_cipher_suite(cipher_suite);
+ if (suite == NULL)
+ return -1;
+
+ if (suite->hash == TLS_HASH_MD5) {
+ rl->hash_alg = CRYPTO_HASH_ALG_HMAC_MD5;
+ rl->hash_size = MD5_MAC_LEN;
+ } else if (suite->hash == TLS_HASH_SHA) {
+ rl->hash_alg = CRYPTO_HASH_ALG_HMAC_SHA1;
+ rl->hash_size = SHA1_MAC_LEN;
+ } else if (suite->hash == TLS_HASH_SHA256) {
+ rl->hash_alg = CRYPTO_HASH_ALG_HMAC_SHA256;
+ rl->hash_size = SHA256_MAC_LEN;
+ }
+
+ data = tls_get_cipher_data(suite->cipher);
+ if (data == NULL)
+ return -1;
+
+ rl->key_material_len = data->key_material;
+ rl->iv_size = data->block_size;
+ rl->cipher_alg = data->alg;
+
+ return 0;
+}
+
+
+/**
+ * tlsv1_record_change_write_cipher - TLS record layer: Change write cipher
+ * @rl: Pointer to TLS record layer data
+ * Returns: 0 on success (cipher changed), -1 on failure
+ *
+ * This function changes TLS record layer to use the new cipher suite
+ * configured with tlsv1_record_set_cipher_suite() for writing.
+ */
+int tlsv1_record_change_write_cipher(struct tlsv1_record_layer *rl)
+{
+ wpa_printf(MSG_DEBUG, "TLSv1: Record Layer - New write cipher suite "
+ "0x%04x", rl->cipher_suite);
+ rl->write_cipher_suite = rl->cipher_suite;
+ os_memset(rl->write_seq_num, 0, TLS_SEQ_NUM_LEN);
+
+ if (rl->write_cbc) {
+ crypto_cipher_deinit(rl->write_cbc);
+ rl->write_cbc = NULL;
+ }
+ if (rl->cipher_alg != CRYPTO_CIPHER_NULL) {
+ rl->write_cbc = crypto_cipher_init(rl->cipher_alg,
+ rl->write_iv, rl->write_key,
+ rl->key_material_len);
+ if (rl->write_cbc == NULL) {
+ wpa_printf(MSG_DEBUG, "TLSv1: Failed to initialize "
+ "cipher");
+ return -1;
+ }
+ }
+
+ return 0;
+}
+
+
+/**
+ * tlsv1_record_change_read_cipher - TLS record layer: Change read cipher
+ * @rl: Pointer to TLS record layer data
+ * Returns: 0 on success (cipher changed), -1 on failure
+ *
+ * This function changes TLS record layer to use the new cipher suite
+ * configured with tlsv1_record_set_cipher_suite() for reading.
+ */
+int tlsv1_record_change_read_cipher(struct tlsv1_record_layer *rl)
+{
+ wpa_printf(MSG_DEBUG, "TLSv1: Record Layer - New read cipher suite "
+ "0x%04x", rl->cipher_suite);
+ rl->read_cipher_suite = rl->cipher_suite;
+ os_memset(rl->read_seq_num, 0, TLS_SEQ_NUM_LEN);
+
+ if (rl->read_cbc) {
+ crypto_cipher_deinit(rl->read_cbc);
+ rl->read_cbc = NULL;
+ }
+ if (rl->cipher_alg != CRYPTO_CIPHER_NULL) {
+ rl->read_cbc = crypto_cipher_init(rl->cipher_alg,
+ rl->read_iv, rl->read_key,
+ rl->key_material_len);
+ if (rl->read_cbc == NULL) {
+ wpa_printf(MSG_DEBUG, "TLSv1: Failed to initialize "
+ "cipher");
+ return -1;
+ }
+ }
+
+ return 0;
+}
+
+
+/**
+ * tlsv1_record_send - TLS record layer: Send a message
+ * @rl: Pointer to TLS record layer data
+ * @content_type: Content type (TLS_CONTENT_TYPE_*)
+ * @buf: Buffer for the generated TLS message (needs to have extra space for
+ * header, IV (TLS v1.1), and HMAC)
+ * @buf_size: Maximum buf size
+ * @payload: Payload to be sent
+ * @payload_len: Length of the payload
+ * @out_len: Buffer for returning the used buf length
+ * Returns: 0 on success, -1 on failure
+ *
+ * This function fills in the TLS record layer header, adds HMAC, and encrypts
+ * the data using the current write cipher.
+ */
+int tlsv1_record_send(struct tlsv1_record_layer *rl, u8 content_type, u8 *buf,
+ size_t buf_size, const u8 *payload, size_t payload_len,
+ size_t *out_len)
+{
+ u8 *pos, *ct_start, *length, *cpayload;
+ struct crypto_hash *hmac;
+ size_t clen;
+ int explicit_iv;
+
+ pos = buf;
+ if (pos + TLS_RECORD_HEADER_LEN > buf + buf_size)
+ return -1;
+
+ /* ContentType type */
+ ct_start = pos;
+ *pos++ = content_type;
+ /* ProtocolVersion version */
+ WPA_PUT_BE16(pos, rl->tls_version);
+ pos += 2;
+ /* uint16 length */
+ length = pos;
+ WPA_PUT_BE16(length, payload_len);
+ pos += 2;
+
+ cpayload = pos;
+ explicit_iv = rl->write_cipher_suite != TLS_NULL_WITH_NULL_NULL &&
+ rl->iv_size && rl->tls_version >= TLS_VERSION_1_1;
+ if (explicit_iv) {
+ /* opaque IV[Cipherspec.block_length] */
+ if (pos + rl->iv_size > buf + buf_size)
+ return -1;
+
+ /*
+ * Use random number R per the RFC 4346, 6.2.3.2 CBC Block
+ * Cipher option 2a.
+ */
+
+ if (os_get_random(pos, rl->iv_size))
+ return -1;
+ pos += rl->iv_size;
+ }
+
+ /*
+ * opaque fragment[TLSPlaintext.length]
+ * (opaque content[TLSCompressed.length] in GenericBlockCipher)
+ */
+ if (pos + payload_len > buf + buf_size)
+ return -1;
+ os_memmove(pos, payload, payload_len);
+ pos += payload_len;
+
+ if (rl->write_cipher_suite != TLS_NULL_WITH_NULL_NULL) {
+ /*
+ * MAC calculated over seq_num + TLSCompressed.type +
+ * TLSCompressed.version + TLSCompressed.length +
+ * TLSCompressed.fragment
+ */
+ hmac = crypto_hash_init(rl->hash_alg, rl->write_mac_secret,
+ rl->hash_size);
+ if (hmac == NULL) {
+ wpa_printf(MSG_DEBUG, "TLSv1: Record Layer - Failed "
+ "to initialize HMAC");
+ return -1;
+ }
+ crypto_hash_update(hmac, rl->write_seq_num, TLS_SEQ_NUM_LEN);
+ /* type + version + length + fragment */
+ crypto_hash_update(hmac, ct_start, TLS_RECORD_HEADER_LEN);
+ crypto_hash_update(hmac, payload, payload_len);
+ clen = buf + buf_size - pos;
+ if (clen < rl->hash_size) {
+ wpa_printf(MSG_DEBUG, "TLSv1: Record Layer - Not "
+ "enough room for MAC");
+ crypto_hash_finish(hmac, NULL, NULL);
+ return -1;
+ }
+
+ if (crypto_hash_finish(hmac, pos, &clen) < 0) {
+ wpa_printf(MSG_DEBUG, "TLSv1: Record Layer - Failed "
+ "to calculate HMAC");
+ return -1;
+ }
+ wpa_hexdump(MSG_MSGDUMP, "TLSv1: Record Layer - Write HMAC",
+ pos, clen);
+ pos += clen;
+ if (rl->iv_size) {
+ size_t len = pos - cpayload;
+ size_t pad;
+ pad = (len + 1) % rl->iv_size;
+ if (pad)
+ pad = rl->iv_size - pad;
+ if (pos + pad + 1 > buf + buf_size) {
+ wpa_printf(MSG_DEBUG, "TLSv1: No room for "
+ "block cipher padding");
+ return -1;
+ }
+ os_memset(pos, pad, pad + 1);
+ pos += pad + 1;
+ }
+
+ if (crypto_cipher_encrypt(rl->write_cbc, cpayload,
+ cpayload, pos - cpayload) < 0)
+ return -1;
+ }
+
+ WPA_PUT_BE16(length, pos - length - 2);
+ inc_byte_array(rl->write_seq_num, TLS_SEQ_NUM_LEN);
+
+ *out_len = pos - buf;
+
+ return 0;
+}
+
+
+/**
+ * tlsv1_record_receive - TLS record layer: Process a received message
+ * @rl: Pointer to TLS record layer data
+ * @in_data: Received data
+ * @in_len: Length of the received data
+ * @out_data: Buffer for output data (must be at least as long as in_data)
+ * @out_len: Set to maximum out_data length by caller; used to return the
+ * length of the used data
+ * @alert: Buffer for returning an alert value on failure
+ * Returns: Number of bytes used from in_data on success, 0 if record was not
+ * complete (more data needed), or -1 on failure
+ *
+ * This function decrypts the received message, verifies HMAC and TLS record
+ * layer header.
+ */
+int tlsv1_record_receive(struct tlsv1_record_layer *rl,
+ const u8 *in_data, size_t in_len,
+ u8 *out_data, size_t *out_len, u8 *alert)
+{
+ size_t i, rlen, hlen;
+ u8 padlen;
+ struct crypto_hash *hmac;
+ u8 len[2], hash[100];
+ int force_mac_error = 0;
+ u8 ct;
+
+ if (in_len < TLS_RECORD_HEADER_LEN) {
+ wpa_printf(MSG_DEBUG, "TLSv1: Too short record (in_len=%lu) - "
+ "need more data",
+ (unsigned long) in_len);
+ wpa_hexdump(MSG_MSGDUMP, "TLSv1: Record Layer - Received",
+ in_data, in_len);
+ return 0;
+ }
+
+ ct = in_data[0];
+ rlen = WPA_GET_BE16(in_data + 3);
+ wpa_printf(MSG_DEBUG, "TLSv1: Received content type %d version %d.%d "
+ "length %d", ct, in_data[1], in_data[2], (int) rlen);
+
+ /*
+ * TLS v1.0 and v1.1 RFCs were not exactly clear on the use of the
+ * protocol version in record layer. As such, accept any {03,xx} value
+ * to remain compatible with existing implementations.
+ */
+ if (in_data[1] != 0x03) {
+ wpa_printf(MSG_DEBUG, "TLSv1: Unexpected protocol version "
+ "%u.%u", in_data[1], in_data[2]);
+ *alert = TLS_ALERT_PROTOCOL_VERSION;
+ return -1;
+ }
+
+ /* TLSCiphertext must not be more than 2^14+2048 bytes */
+ if (TLS_RECORD_HEADER_LEN + rlen > 18432) {
+ wpa_printf(MSG_DEBUG, "TLSv1: Record overflow (len=%lu)",
+ (unsigned long) (TLS_RECORD_HEADER_LEN + rlen));
+ *alert = TLS_ALERT_RECORD_OVERFLOW;
+ return -1;
+ }
+
+ in_data += TLS_RECORD_HEADER_LEN;
+ in_len -= TLS_RECORD_HEADER_LEN;
+
+ if (rlen > in_len) {
+ wpa_printf(MSG_DEBUG, "TLSv1: Not all record data included "
+ "(rlen=%lu > in_len=%lu)",
+ (unsigned long) rlen, (unsigned long) in_len);
+ return 0;
+ }
+
+ wpa_hexdump(MSG_MSGDUMP, "TLSv1: Record Layer - Received",
+ in_data, rlen);
+
+ if (ct != TLS_CONTENT_TYPE_HANDSHAKE &&
+ ct != TLS_CONTENT_TYPE_CHANGE_CIPHER_SPEC &&
+ ct != TLS_CONTENT_TYPE_ALERT &&
+ ct != TLS_CONTENT_TYPE_APPLICATION_DATA) {
+ wpa_printf(MSG_DEBUG, "TLSv1: Ignore record with unknown "
+ "content type 0x%x", ct);
+ *alert = TLS_ALERT_UNEXPECTED_MESSAGE;
+ return -1;
+ }
+
+ in_len = rlen;
+
+ if (*out_len < in_len) {
+ wpa_printf(MSG_DEBUG, "TLSv1: Not enough output buffer for "
+ "processing received record");
+ *alert = TLS_ALERT_INTERNAL_ERROR;
+ return -1;
+ }
+
+ if (rl->read_cipher_suite != TLS_NULL_WITH_NULL_NULL) {
+ size_t plen;
+ if (crypto_cipher_decrypt(rl->read_cbc, in_data,
+ out_data, in_len) < 0) {
+ *alert = TLS_ALERT_DECRYPTION_FAILED;
+ return -1;
+ }
+ plen = in_len;
+ wpa_hexdump_key(MSG_MSGDUMP, "TLSv1: Record Layer - Decrypted "
+ "data", out_data, plen);
+
+ if (rl->iv_size) {
+ /*
+ * TLS v1.0 defines different alert values for various
+ * failures. That may information to aid in attacks, so
+ * use the same bad_record_mac alert regardless of the
+ * issues.
+ *
+ * In addition, instead of returning immediately on
+ * error, run through the MAC check to make timing
+ * attacks more difficult.
+ */
+
+ if (rl->tls_version >= TLS_VERSION_1_1) {
+ /* Remove opaque IV[Cipherspec.block_length] */
+ if (plen < rl->iv_size) {
+ wpa_printf(MSG_DEBUG, "TLSv1.1: Not "
+ "enough room for IV");
+ force_mac_error = 1;
+ goto check_mac;
+ }
+ os_memmove(out_data, out_data + rl->iv_size,
+ plen - rl->iv_size);
+ plen -= rl->iv_size;
+ }
+
+ /* Verify and remove padding */
+ if (plen == 0) {
+ wpa_printf(MSG_DEBUG, "TLSv1: Too short record"
+ " (no pad)");
+ force_mac_error = 1;
+ goto check_mac;
+ }
+ padlen = out_data[plen - 1];
+ if (padlen >= plen) {
+ wpa_printf(MSG_DEBUG, "TLSv1: Incorrect pad "
+ "length (%u, plen=%lu) in "
+ "received record",
+ padlen, (unsigned long) plen);
+ force_mac_error = 1;
+ goto check_mac;
+ }
+ for (i = plen - padlen - 1; i < plen - 1; i++) {
+ if (out_data[i] != padlen) {
+ wpa_hexdump(MSG_DEBUG,
+ "TLSv1: Invalid pad in "
+ "received record",
+ out_data + plen - padlen -
+ 1, padlen + 1);
+ force_mac_error = 1;
+ goto check_mac;
+ }
+ }
+
+ plen -= padlen + 1;
+
+ wpa_hexdump_key(MSG_MSGDUMP, "TLSv1: Record Layer - "
+ "Decrypted data with IV and padding "
+ "removed", out_data, plen);
+ }
+
+ check_mac:
+ if (plen < rl->hash_size) {
+ wpa_printf(MSG_DEBUG, "TLSv1: Too short record; no "
+ "hash value");
+ *alert = TLS_ALERT_BAD_RECORD_MAC;
+ return -1;
+ }
+
+ plen -= rl->hash_size;
+
+ hmac = crypto_hash_init(rl->hash_alg, rl->read_mac_secret,
+ rl->hash_size);
+ if (hmac == NULL) {
+ wpa_printf(MSG_DEBUG, "TLSv1: Record Layer - Failed "
+ "to initialize HMAC");
+ *alert = TLS_ALERT_INTERNAL_ERROR;
+ return -1;
+ }
+
+ crypto_hash_update(hmac, rl->read_seq_num, TLS_SEQ_NUM_LEN);
+ /* type + version + length + fragment */
+ crypto_hash_update(hmac, in_data - TLS_RECORD_HEADER_LEN, 3);
+ WPA_PUT_BE16(len, plen);
+ crypto_hash_update(hmac, len, 2);
+ crypto_hash_update(hmac, out_data, plen);
+ hlen = sizeof(hash);
+ if (crypto_hash_finish(hmac, hash, &hlen) < 0) {
+ wpa_printf(MSG_DEBUG, "TLSv1: Record Layer - Failed "
+ "to calculate HMAC");
+ *alert = TLS_ALERT_INTERNAL_ERROR;
+ return -1;
+ }
+ if (hlen != rl->hash_size ||
+ os_memcmp_const(hash, out_data + plen, hlen) != 0 ||
+ force_mac_error) {
+ wpa_printf(MSG_DEBUG, "TLSv1: Invalid HMAC value in "
+ "received message (force_mac_error=%d)",
+ force_mac_error);
+ *alert = TLS_ALERT_BAD_RECORD_MAC;
+ return -1;
+ }
+
+ *out_len = plen;
+ } else {
+ os_memcpy(out_data, in_data, in_len);
+ *out_len = in_len;
+ }
+
+ /* TLSCompressed must not be more than 2^14+1024 bytes */
+ if (TLS_RECORD_HEADER_LEN + *out_len > 17408) {
+ wpa_printf(MSG_DEBUG, "TLSv1: Record overflow (len=%lu)",
+ (unsigned long) (TLS_RECORD_HEADER_LEN + *out_len));
+ *alert = TLS_ALERT_RECORD_OVERFLOW;
+ return -1;
+ }
+
+ inc_byte_array(rl->read_seq_num, TLS_SEQ_NUM_LEN);
+
+ return TLS_RECORD_HEADER_LEN + rlen;
+}
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