net: tls: Add tls 1.3 support
TLS 1.3 has minor changes from TLS 1.2 at the record layer. * Header now hardcodes the same version and application content type in the header. * The real content type is appended after the data, before encryption (or after decryption). * The IV is xored with the sequence number, instead of concatinating four bytes of IV with the explicit IV. * Zero-padding: No exlicit length is given, we search backwards from the end of the decrypted data for the first non-zero byte, which is the content type. Currently recv supports reading zero-padding, but there is no way for send to add zero padding. Signed-off-by: Dave Watson <davejwatson@fb.com> Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Dave Watson
David S. Miller
Родитель
fedf201e12
Коммит
130b392c6c
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@ -119,6 +119,9 @@ struct tls_rec {
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/* AAD | msg_encrypted.sg.data (data contains overhead for hdr & iv & tag) */
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struct scatterlist sg_aead_out[2];
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char content_type;
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struct scatterlist sg_content_type;
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char aad_space[TLS_AAD_SPACE_SIZE];
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u8 iv_data[TLS_CIPHER_AES_GCM_128_IV_SIZE +
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TLS_CIPHER_AES_GCM_128_SALT_SIZE];
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@ -203,6 +206,7 @@ struct cipher_context {
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u16 rec_seq_size;
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char *rec_seq;
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u16 aad_size;
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u16 tail_size;
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};
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union tls_crypto_context {
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@ -397,49 +401,77 @@ static inline bool tls_bigint_increment(unsigned char *seq, int len)
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}
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static inline void tls_advance_record_sn(struct sock *sk,
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struct cipher_context *ctx)
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struct cipher_context *ctx,
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int version)
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{
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if (tls_bigint_increment(ctx->rec_seq, ctx->rec_seq_size))
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tls_err_abort(sk, EBADMSG);
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tls_bigint_increment(ctx->iv + TLS_CIPHER_AES_GCM_128_SALT_SIZE,
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ctx->iv_size);
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if (version != TLS_1_3_VERSION) {
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tls_bigint_increment(ctx->iv + TLS_CIPHER_AES_GCM_128_SALT_SIZE,
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ctx->iv_size);
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}
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}
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static inline void tls_fill_prepend(struct tls_context *ctx,
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char *buf,
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size_t plaintext_len,
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unsigned char record_type)
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unsigned char record_type,
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int version)
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{
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size_t pkt_len, iv_size = ctx->tx.iv_size;
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pkt_len = plaintext_len + iv_size + ctx->tx.tag_size;
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pkt_len = plaintext_len + ctx->tx.tag_size;
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if (version != TLS_1_3_VERSION) {
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pkt_len += iv_size;
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memcpy(buf + TLS_NONCE_OFFSET,
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ctx->tx.iv + TLS_CIPHER_AES_GCM_128_SALT_SIZE, iv_size);
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}
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/* we cover nonce explicit here as well, so buf should be of
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* size KTLS_DTLS_HEADER_SIZE + KTLS_DTLS_NONCE_EXPLICIT_SIZE
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*/
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buf[0] = record_type;
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buf[1] = TLS_VERSION_MINOR(ctx->crypto_send.info.version);
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buf[2] = TLS_VERSION_MAJOR(ctx->crypto_send.info.version);
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buf[0] = version == TLS_1_3_VERSION ?
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TLS_RECORD_TYPE_DATA : record_type;
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/* Note that VERSION must be TLS_1_2 for both TLS1.2 and TLS1.3 */
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buf[1] = TLS_1_2_VERSION_MINOR;
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buf[2] = TLS_1_2_VERSION_MAJOR;
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/* we can use IV for nonce explicit according to spec */
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buf[3] = pkt_len >> 8;
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buf[4] = pkt_len & 0xFF;
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memcpy(buf + TLS_NONCE_OFFSET,
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ctx->tx.iv + TLS_CIPHER_AES_GCM_128_SALT_SIZE, iv_size);
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}
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static inline void tls_make_aad(char *buf,
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size_t size,
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char *record_sequence,
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int record_sequence_size,
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unsigned char record_type)
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unsigned char record_type,
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int version)
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{
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memcpy(buf, record_sequence, record_sequence_size);
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if (version != TLS_1_3_VERSION) {
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memcpy(buf, record_sequence, record_sequence_size);
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buf += 8;
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} else {
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size += TLS_CIPHER_AES_GCM_128_TAG_SIZE;
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}
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buf[8] = record_type;
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buf[9] = TLS_1_2_VERSION_MAJOR;
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buf[10] = TLS_1_2_VERSION_MINOR;
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buf[11] = size >> 8;
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buf[12] = size & 0xFF;
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buf[0] = version == TLS_1_3_VERSION ?
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TLS_RECORD_TYPE_DATA : record_type;
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buf[1] = TLS_1_2_VERSION_MAJOR;
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buf[2] = TLS_1_2_VERSION_MINOR;
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buf[3] = size >> 8;
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buf[4] = size & 0xFF;
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}
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static inline void xor_iv_with_seq(int version, char *iv, char *seq)
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{
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int i;
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if (version == TLS_1_3_VERSION) {
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for (i = 0; i < 8; i++)
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iv[i + 4] ^= seq[i];
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}
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}
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static inline struct tls_context *tls_get_ctx(const struct sock *sk)
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@ -51,6 +51,10 @@
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#define TLS_1_2_VERSION_MINOR 0x3
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#define TLS_1_2_VERSION TLS_VERSION_NUMBER(TLS_1_2)
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#define TLS_1_3_VERSION_MAJOR 0x3
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#define TLS_1_3_VERSION_MINOR 0x4
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#define TLS_1_3_VERSION TLS_VERSION_NUMBER(TLS_1_3)
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/* Supported ciphers */
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#define TLS_CIPHER_AES_GCM_128 51
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#define TLS_CIPHER_AES_GCM_128_IV_SIZE 8
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@ -257,7 +257,8 @@ static int tls_push_record(struct sock *sk,
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tls_fill_prepend(ctx,
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skb_frag_address(frag),
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record->len - ctx->tx.prepend_size,
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record_type);
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record_type,
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ctx->crypto_send.info.version);
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/* HW doesn't care about the data in the tag, because it fills it. */
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dummy_tag_frag.page = skb_frag_page(frag);
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@ -270,7 +271,7 @@ static int tls_push_record(struct sock *sk,
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spin_unlock_irq(&offload_ctx->lock);
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offload_ctx->open_record = NULL;
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set_bit(TLS_PENDING_CLOSED_RECORD, &ctx->flags);
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tls_advance_record_sn(sk, &ctx->tx);
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tls_advance_record_sn(sk, &ctx->tx, ctx->crypto_send.info.version);
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for (i = 0; i < record->num_frags; i++) {
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frag = &record->frags[i];
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@ -73,7 +73,8 @@ static int tls_enc_record(struct aead_request *aead_req,
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len -= TLS_CIPHER_AES_GCM_128_IV_SIZE;
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tls_make_aad(aad, len - TLS_CIPHER_AES_GCM_128_TAG_SIZE,
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(char *)&rcd_sn, sizeof(rcd_sn), buf[0]);
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(char *)&rcd_sn, sizeof(rcd_sn), buf[0],
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TLS_1_2_VERSION);
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memcpy(iv + TLS_CIPHER_AES_GCM_128_SALT_SIZE, buf + TLS_HEADER_SIZE,
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TLS_CIPHER_AES_GCM_128_IV_SIZE);
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@ -463,7 +463,8 @@ static int do_tls_setsockopt_conf(struct sock *sk, char __user *optval,
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}
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/* check version */
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if (crypto_info->version != TLS_1_2_VERSION) {
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if (crypto_info->version != TLS_1_2_VERSION &&
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crypto_info->version != TLS_1_3_VERSION) {
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rc = -ENOTSUPP;
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goto err_crypto_info;
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}
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116
net/tls/tls_sw.c
116
net/tls/tls_sw.c
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@ -120,6 +120,34 @@ static int skb_nsg(struct sk_buff *skb, int offset, int len)
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return __skb_nsg(skb, offset, len, 0);
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}
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static int padding_length(struct tls_sw_context_rx *ctx,
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struct tls_context *tls_ctx, struct sk_buff *skb)
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{
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struct strp_msg *rxm = strp_msg(skb);
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int sub = 0;
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/* Determine zero-padding length */
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if (tls_ctx->crypto_recv.info.version == TLS_1_3_VERSION) {
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char content_type = 0;
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int err;
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int back = 17;
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while (content_type == 0) {
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if (back > rxm->full_len)
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return -EBADMSG;
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err = skb_copy_bits(skb,
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rxm->offset + rxm->full_len - back,
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&content_type, 1);
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if (content_type)
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break;
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sub++;
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back++;
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}
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ctx->control = content_type;
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}
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return sub;
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}
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static void tls_decrypt_done(struct crypto_async_request *req, int err)
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{
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struct aead_request *aead_req = (struct aead_request *)req;
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@ -142,7 +170,7 @@ static void tls_decrypt_done(struct crypto_async_request *req, int err)
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tls_err_abort(skb->sk, err);
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} else {
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struct strp_msg *rxm = strp_msg(skb);
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rxm->full_len -= padding_length(ctx, tls_ctx, skb);
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rxm->offset += tls_ctx->rx.prepend_size;
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rxm->full_len -= tls_ctx->rx.overhead_size;
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}
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@ -448,6 +476,8 @@ static int tls_do_encryption(struct sock *sk,
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int rc;
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memcpy(rec->iv_data, tls_ctx->tx.iv, sizeof(rec->iv_data));
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xor_iv_with_seq(tls_ctx->crypto_send.info.version, rec->iv_data,
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tls_ctx->tx.rec_seq);
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sge->offset += tls_ctx->tx.prepend_size;
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sge->length -= tls_ctx->tx.prepend_size;
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@ -483,7 +513,8 @@ static int tls_do_encryption(struct sock *sk,
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/* Unhook the record from context if encryption is not failure */
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ctx->open_rec = NULL;
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tls_advance_record_sn(sk, &tls_ctx->tx);
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tls_advance_record_sn(sk, &tls_ctx->tx,
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tls_ctx->crypto_send.info.version);
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return rc;
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}
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@ -640,7 +671,17 @@ static int tls_push_record(struct sock *sk, int flags,
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i = msg_pl->sg.end;
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sk_msg_iter_var_prev(i);
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sg_mark_end(sk_msg_elem(msg_pl, i));
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rec->content_type = record_type;
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if (tls_ctx->crypto_send.info.version == TLS_1_3_VERSION) {
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/* Add content type to end of message. No padding added */
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sg_set_buf(&rec->sg_content_type, &rec->content_type, 1);
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sg_mark_end(&rec->sg_content_type);
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sg_chain(msg_pl->sg.data, msg_pl->sg.end + 1,
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&rec->sg_content_type);
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} else {
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sg_mark_end(sk_msg_elem(msg_pl, i));
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}
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i = msg_pl->sg.start;
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sg_chain(rec->sg_aead_in, 2, rec->inplace_crypto ?
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@ -653,18 +694,22 @@ static int tls_push_record(struct sock *sk, int flags,
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i = msg_en->sg.start;
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sg_chain(rec->sg_aead_out, 2, &msg_en->sg.data[i]);
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tls_make_aad(rec->aad_space, msg_pl->sg.size,
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tls_make_aad(rec->aad_space, msg_pl->sg.size + tls_ctx->tx.tail_size,
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tls_ctx->tx.rec_seq, tls_ctx->tx.rec_seq_size,
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record_type);
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record_type,
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tls_ctx->crypto_send.info.version);
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tls_fill_prepend(tls_ctx,
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page_address(sg_page(&msg_en->sg.data[i])) +
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msg_en->sg.data[i].offset, msg_pl->sg.size,
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record_type);
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msg_en->sg.data[i].offset,
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msg_pl->sg.size + tls_ctx->tx.tail_size,
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record_type,
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tls_ctx->crypto_send.info.version);
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tls_ctx->pending_open_record_frags = false;
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rc = tls_do_encryption(sk, tls_ctx, ctx, req, msg_pl->sg.size, i);
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rc = tls_do_encryption(sk, tls_ctx, ctx, req,
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msg_pl->sg.size + tls_ctx->tx.tail_size, i);
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if (rc < 0) {
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if (rc != -EINPROGRESS) {
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tls_err_abort(sk, EBADMSG);
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@ -1292,7 +1337,8 @@ static int decrypt_internal(struct sock *sk, struct sk_buff *skb,
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u8 *aad, *iv, *mem = NULL;
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struct scatterlist *sgin = NULL;
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struct scatterlist *sgout = NULL;
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const int data_len = rxm->full_len - tls_ctx->rx.overhead_size;
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const int data_len = rxm->full_len - tls_ctx->rx.overhead_size +
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tls_ctx->rx.tail_size;
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if (*zc && (out_iov || out_sg)) {
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if (out_iov)
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@ -1343,12 +1389,20 @@ static int decrypt_internal(struct sock *sk, struct sk_buff *skb,
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kfree(mem);
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return err;
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}
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memcpy(iv, tls_ctx->rx.iv, TLS_CIPHER_AES_GCM_128_SALT_SIZE);
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if (tls_ctx->crypto_recv.info.version == TLS_1_3_VERSION)
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memcpy(iv, tls_ctx->rx.iv, crypto_aead_ivsize(ctx->aead_recv));
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else
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memcpy(iv, tls_ctx->rx.iv, TLS_CIPHER_AES_GCM_128_SALT_SIZE);
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xor_iv_with_seq(tls_ctx->crypto_recv.info.version, iv,
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tls_ctx->rx.rec_seq);
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/* Prepare AAD */
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tls_make_aad(aad, rxm->full_len - tls_ctx->rx.overhead_size,
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tls_make_aad(aad, rxm->full_len - tls_ctx->rx.overhead_size +
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tls_ctx->rx.tail_size,
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tls_ctx->rx.rec_seq, tls_ctx->rx.rec_seq_size,
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ctx->control);
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ctx->control,
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tls_ctx->crypto_recv.info.version);
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/* Prepare sgin */
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sg_init_table(sgin, n_sgin);
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@ -1405,6 +1459,7 @@ static int decrypt_skb_update(struct sock *sk, struct sk_buff *skb,
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{
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struct tls_context *tls_ctx = tls_get_ctx(sk);
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struct tls_sw_context_rx *ctx = tls_sw_ctx_rx(tls_ctx);
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int version = tls_ctx->crypto_recv.info.version;
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struct strp_msg *rxm = strp_msg(skb);
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int err = 0;
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@ -1417,13 +1472,17 @@ static int decrypt_skb_update(struct sock *sk, struct sk_buff *skb,
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err = decrypt_internal(sk, skb, dest, NULL, chunk, zc, async);
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if (err < 0) {
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if (err == -EINPROGRESS)
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tls_advance_record_sn(sk, &tls_ctx->rx);
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tls_advance_record_sn(sk, &tls_ctx->rx,
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version);
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return err;
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}
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rxm->full_len -= padding_length(ctx, tls_ctx, skb);
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rxm->offset += tls_ctx->rx.prepend_size;
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rxm->full_len -= tls_ctx->rx.overhead_size;
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tls_advance_record_sn(sk, &tls_ctx->rx);
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tls_advance_record_sn(sk, &tls_ctx->rx, version);
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ctx->decrypted = true;
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ctx->saved_data_ready(sk);
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} else {
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@ -1611,7 +1670,8 @@ int tls_sw_recvmsg(struct sock *sk,
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to_decrypt = rxm->full_len - tls_ctx->rx.overhead_size;
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|
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if (to_decrypt <= len && !is_kvec && !is_peek &&
|
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ctx->control == TLS_RECORD_TYPE_DATA)
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ctx->control == TLS_RECORD_TYPE_DATA &&
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tls_ctx->crypto_recv.info.version != TLS_1_3_VERSION)
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zc = true;
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err = decrypt_skb_update(sk, skb, &msg->msg_iter,
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@ -1835,9 +1895,12 @@ static int tls_read_size(struct strparser *strp, struct sk_buff *skb)
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data_len = ((header[4] & 0xFF) | (header[3] << 8));
|
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|
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cipher_overhead = tls_ctx->rx.tag_size + tls_ctx->rx.iv_size;
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cipher_overhead = tls_ctx->rx.tag_size;
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if (tls_ctx->crypto_recv.info.version != TLS_1_3_VERSION)
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cipher_overhead += tls_ctx->rx.iv_size;
|
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|
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if (data_len > TLS_MAX_PAYLOAD_SIZE + cipher_overhead) {
|
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if (data_len > TLS_MAX_PAYLOAD_SIZE + cipher_overhead +
|
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tls_ctx->rx.tail_size) {
|
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ret = -EMSGSIZE;
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goto read_failure;
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}
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@ -1846,12 +1909,12 @@ static int tls_read_size(struct strparser *strp, struct sk_buff *skb)
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goto read_failure;
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}
|
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|
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if (header[1] != TLS_VERSION_MINOR(tls_ctx->crypto_recv.info.version) ||
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header[2] != TLS_VERSION_MAJOR(tls_ctx->crypto_recv.info.version)) {
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/* Note that both TLS1.3 and TLS1.2 use TLS_1_2 version here */
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if (header[1] != TLS_1_2_VERSION_MINOR ||
|
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header[2] != TLS_1_2_VERSION_MAJOR) {
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ret = -EINVAL;
|
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goto read_failure;
|
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}
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|
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#ifdef CONFIG_TLS_DEVICE
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handle_device_resync(strp->sk, TCP_SKB_CB(skb)->seq + rxm->offset,
|
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*(u64*)tls_ctx->rx.rec_seq);
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|
|
@ -2100,10 +2163,19 @@ int tls_set_sw_offload(struct sock *sk, struct tls_context *ctx, int tx)
|
|||
goto free_priv;
|
||||
}
|
||||
|
||||
cctx->aad_size = TLS_AAD_SPACE_SIZE;
|
||||
if (crypto_info->version == TLS_1_3_VERSION) {
|
||||
nonce_size = 0;
|
||||
cctx->aad_size = TLS_HEADER_SIZE;
|
||||
cctx->tail_size = 1;
|
||||
} else {
|
||||
cctx->aad_size = TLS_AAD_SPACE_SIZE;
|
||||
cctx->tail_size = 0;
|
||||
}
|
||||
|
||||
cctx->prepend_size = TLS_HEADER_SIZE + nonce_size;
|
||||
cctx->tag_size = tag_size;
|
||||
cctx->overhead_size = cctx->prepend_size + cctx->tag_size;
|
||||
cctx->overhead_size = cctx->prepend_size + cctx->tag_size +
|
||||
cctx->tail_size;
|
||||
cctx->iv_size = iv_size;
|
||||
cctx->iv = kmalloc(iv_size + TLS_CIPHER_AES_GCM_128_SALT_SIZE,
|
||||
GFP_KERNEL);
|
||||
|
|
|
|||
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Ссылка в новой задаче