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[70.77.224.58]) by smtp.gmail.com with ESMTPSA id x15sm49823522pfa.80.2021.01.01.19.50.33 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 01 Jan 2021 19:50:33 -0800 (PST) Sender: Sheng Mao From: shngmao@gmail.com To: wangyugui@e16-tech.com Cc: linux-btrfs@vger.kernel.org, Sheng Mao Subject: [PATCH v2 1/3] btrfs-progs: add Kernel TLS to btrfs send/receive Date: Fri, 1 Jan 2021 20:49:55 -0700 Message-Id: <20210102034957.2825531-1-shngmao@gmail.com> X-Mailer: git-send-email 2.29.2 In-Reply-To: <20210101135350.AD49.409509F4@e16-tech.com> References: <20210101135350.AD49.409509F4@e16-tech.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@vger.kernel.org From: Sheng Mao Currently, btrfs send outputs to a pipe or a file; btrfs receive inputs from a pipe or a file. The pipe can be a SSH or a stunnel connection. btrfs send/receive itself doesn't handle any connection. Kernel introduces TLS in version 4.13 (referred as ktls). Ktls provides a transparent TLS 1.2/1.3 connection: from user space aspect, applications use a normal socket fd to read/write from/to. This model fits into btrfs send's design well: btrfs first writes to a pipe and then splices data from pipe to the final fd (which is a file or pipe). Ktls simply replaces the final fd with the ktls socket fd. According to ktls' author, ktls can boost performance for 2~7%. Ktls helps less on receiving side: btrfs receive processes data in user space. But btrfs receive still can use transparent TLS layer. I have implemented ktls for btrfs send/receive. Here are the key features: - Use GnuTLS for handshake. OpenSSL is not suitable for this task, we need to pass IV and key from handshake session to kernel setting. - Use PSK (pre-shared key) for handshake. User can use --key to use a key file or input password on prompt. - Key file is checked as PEM format first; if it fails, key file is treated as raw binary file. - Three TLS modes are supported: none (raw TCP), TLS 1.2 + GCM 128/256, TLS 1.3 + GCM 128. - DTLS, certificate, Secure Remote Password (SRP) are not supported yet. Issue: #326 Signed-off-by: Sheng Mao --- common/ktls.c | 702 ++++++++++++++++++++++++++++++++++++++++++++++++++ common/ktls.h | 57 ++++ 2 files changed, 759 insertions(+) create mode 100644 common/ktls.c create mode 100644 common/ktls.h diff --git a/common/ktls.c b/common/ktls.c new file mode 100644 index 00000000..a4d670e3 --- /dev/null +++ b/common/ktls.c @@ -0,0 +1,702 @@ +/* + * Copyright (C) 2020 Sheng Mao. All rights reserved. + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public + * License v2 as published by the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * General Public License for more details. + */ + +#include +#include +#include + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include + +#include + +#include + +#include "ktls.h" + +enum { KTLS_MAX_PASSWORD_LENGTH = 256, KTLS_MAX_PRIORITY_STRING_LENTH = 256 }; + +enum { + KTLS_STAGE_NOT_HANDSHAKED, + KTLS_STAGE_HAS_HANDSHAKED, +}; + +enum ktls_tls_mode_t { + KTLS_TLS_MODE_NONE = 0, + KTLS_TLS_12_128_GCM, + KTLS_TLS_13_128_GCM, + KTLS_TLS_12_256_GCM +}; + +struct ktls_session { + gnutls_session_t session; + gnutls_certificate_credentials_t crt_cred; + + gnutls_psk_server_credentials_t psk_cred_server; + gnutls_psk_client_credentials_t psk_cred_client; + + uint8_t role; + uint8_t stage; + enum ktls_tls_mode_t tls_mode; +}; + +static gnutls_datum_t ktls_psk_username = { 0 }; +static gnutls_datum_t ktls_psk_key = { 0 }; + +static void ktls_print_logs(int level, const char *msg) +{ + if (bconf.verbose >= level) + printf("GnuTLS [%d]: %s", level, msg); +} + +int ktls_set_psk_session_from_password_prompt(struct ktls_session *session, + const char *username) +{ + struct termios orig_term_flags, passwd_term_flags; + char passwd[KTLS_MAX_PASSWORD_LENGTH]; + int passwd_sz = 0; + int stdin_fd = 0; + + if (!session) + return EXIT_FAILURE; + + if (session->tls_mode == KTLS_TLS_MODE_NONE) + return EXIT_SUCCESS; + + passwd[0] = '\0'; + + stdin_fd = fileno(stdin); + + if (!isatty(stdin_fd)) { + error("tty needed for password input"); + return EXIT_FAILURE; + } + + tcgetattr(stdin_fd, &orig_term_flags); + passwd_term_flags = orig_term_flags; + passwd_term_flags.c_lflag &= ~ECHO; + passwd_term_flags.c_lflag |= ECHONL; + + if (tcsetattr(stdin_fd, TCSANOW, &passwd_term_flags)) { + error("fail to hide password: %s", strerror(errno)); + return EXIT_FAILURE; + } + + printf("password: "); + if (!fgets(passwd, sizeof(passwd), stdin)) { + error("no password read"); + return EXIT_FAILURE; + } + + if (tcsetattr(fileno(stdin), TCSANOW, &orig_term_flags)) { + error("fail to reset tty: %s", strerror(errno)); + return EXIT_FAILURE; + } + + passwd_sz = strlen(passwd); + if (passwd_sz <= 0) { + error("no password read"); + return EXIT_FAILURE; + } + if (passwd[passwd_sz - 1] == '\n') { + passwd[passwd_sz - 1] = '\0'; + passwd_sz--; + } + + return ktls_set_psk_session(session, username, + (const unsigned char *)passwd, passwd_sz); +} + +int ktls_set_psk_session_from_keyfile(struct ktls_session *session, + const char *username, + const char *key_file) +{ + int rc = GNUTLS_E_SUCCESS; + struct stat file_stat; + size_t sz = 0; + FILE *fp = NULL; + gnutls_datum_t input = { NULL, 0UL }; + gnutls_datum_t output = { NULL, 0UL }; + + if (!session) + goto cleanup; + + if (session->tls_mode == KTLS_TLS_MODE_NONE) + return EXIT_SUCCESS; + + if (stat(key_file, &file_stat)) { + error("fail to open keyfile: %s", strerror(errno)); + goto cleanup; + } + + fp = fopen(key_file, "r"); + if (!fp) { + error("fail to open keyfile: %s", strerror(errno)); + goto cleanup; + } + + input.size = file_stat.st_size; + + input.data = gnutls_malloc(input.size); + + sz = fread(input.data, 1, input.size, fp); + + if (sz != input.size) { + error("fail to read PEM"); + goto cleanup; + } + + rc = gnutls_pem_base64_decode2(NULL, &input, &output); + if (rc != GNUTLS_E_SUCCESS) { + error("Error! fail to decode PEM: %s", gnutls_strerror(rc)); + goto cleanup; + } + + return ktls_set_psk_session(session, username, output.data, + output.size); + +cleanup: + return EXIT_FAILURE; +} + +struct ktls_session *ktls_create_session(bool is_sender) +{ + struct ktls_session *session = NULL; + + session = (struct ktls_session *)malloc(sizeof(struct ktls_session)); + explicit_bzero(session, sizeof(*session)); + + gnutls_global_init(); + + session->role = is_sender ? GNUTLS_CLIENT : GNUTLS_SERVER; + session->stage = KTLS_STAGE_NOT_HANDSHAKED; + + gnutls_init(&session->session, session->role); + + gnutls_global_set_log_level(bconf.verbose); + gnutls_global_set_log_function(ktls_print_logs); + + return session; +} + +void ktls_destroy_session(struct ktls_session *session) +{ + if (!session) + return; + + if (session->crt_cred) + gnutls_certificate_free_credentials(session->crt_cred); + + if (session->psk_cred_server) + gnutls_psk_free_server_credentials(session->psk_cred_server); + + if (session->psk_cred_client) + gnutls_psk_free_client_credentials(session->psk_cred_client); + + if (session->session) { + if (session->stage == KTLS_STAGE_HAS_HANDSHAKED) + gnutls_bye(session->session, GNUTLS_SHUT_RDWR); + gnutls_deinit(session->session); + } + + gnutls_global_deinit(); + + explicit_bzero(session, sizeof(*session)); +} + +static int ktls_connect_or_bind(int *sock, bool is_sender, int protocol, + struct sockaddr *serv_addr, size_t serv_addr_sz) +{ + *sock = 0; + + *sock = socket(protocol, SOCK_STREAM, 0); + if (*sock == KTLS_INVALID_FD) { + error("could not create socket: %s", strerror(errno)); + goto cleanup; + } + + if (is_sender) { + if (connect(*sock, serv_addr, serv_addr_sz)) { + error("fail to connect to server: %s", strerror(errno)); + goto cleanup; + } + return EXIT_SUCCESS; + } + + if (setsockopt(*sock, SOL_SOCKET, SO_REUSEADDR, &(int){ 1 }, + sizeof(int))) { + error("fail to connect to server: %s", strerror(errno)); + goto cleanup; + } + + if (bind(*sock, serv_addr, serv_addr_sz) || listen(*sock, 1)) { + error("fail to serve as server: %s", strerror(errno)); + goto cleanup; + } + + return EXIT_SUCCESS; + +cleanup: + if (*sock >= 0) + close(*sock); + return EXIT_FAILURE; +} + +static int ktls_connect_domain(int *sock, bool is_sender, const char *host, + const uint16_t port) +{ + struct addrinfo hints = { 0 }, *res = NULL; + int rc = 0; + struct sockaddr_in addr4; + struct sockaddr_in6 addr6; + + memset(&hints, 0, sizeof(hints)); + + hints.ai_family = PF_UNSPEC; + hints.ai_socktype = SOCK_STREAM; + hints.ai_flags |= AI_CANONNAME; + + if (getaddrinfo(host, NULL, &hints, &res)) { + error("fail to get address info: %s", strerror(errno)); + return EXIT_FAILURE; + } + + while (res) { + switch (res->ai_family) { + case AF_INET: + explicit_bzero(&addr4, sizeof(addr4)); + addr4.sin_addr = + ((struct sockaddr_in *)res->ai_addr)->sin_addr; + addr4.sin_port = port; + addr4.sin_family = res->ai_family; + if (!ktls_connect_or_bind( + sock, is_sender, res->ai_family, + (struct sockaddr *)&addr4, sizeof(addr4))) { + goto cleanup; + } + break; + case AF_INET6: + explicit_bzero(&addr6, sizeof(addr6)); + addr6.sin6_addr = + ((struct sockaddr_in6 *)res->ai_addr)->sin6_addr; + addr6.sin6_port = port; + addr6.sin6_family = res->ai_family; + if (!ktls_connect_or_bind( + sock, is_sender, res->ai_family, + (struct sockaddr *)&addr6, sizeof(addr6))) { + goto cleanup; + } + break; + } + res = res->ai_next; + } + + freeaddrinfo(res); + return EXIT_FAILURE; + +cleanup: + freeaddrinfo(res); + return rc; +} + +static int ktls_connect_ip(int *sock, bool is_sender, const char *host, + const uint16_t port) +{ + struct sockaddr_in addr4; + struct sockaddr_in6 addr6; + struct sockaddr *serv_addr = NULL; + size_t serv_addr_sz = 0; + sa_family_t protol = AF_INET; + + explicit_bzero(&addr4, sizeof(addr4)); + explicit_bzero(&addr6, sizeof(addr6)); + + if (inet_pton(AF_INET, host, &addr4.sin_addr) == 1) { + serv_addr = (struct sockaddr *)&addr4; + serv_addr_sz = sizeof(addr4); + protol = addr4.sin_family = AF_INET; + addr4.sin_port = port; + } + + if (!serv_addr && inet_pton(AF_INET6, host, &addr6.sin6_addr) == 1) { + serv_addr = (struct sockaddr *)&addr6; + serv_addr_sz = sizeof(addr6); + protol = addr6.sin6_family = AF_INET6; + addr6.sin6_port = port; + } + + if (!serv_addr) + return KTLS_INVALID_FD; + + return ktls_connect_or_bind(sock, is_sender, protol, serv_addr, + serv_addr_sz); +} + +int ktls_set_tls_mode(struct ktls_session *session, const char *mode) +{ + if (!session) + return EXIT_FAILURE; + + if (!strcmp("none", mode)) + session->tls_mode = KTLS_TLS_MODE_NONE; + else if (!strcmp("tls_12_128_gcm", mode)) + session->tls_mode = KTLS_TLS_12_128_GCM; + else if (!strcmp("tls_13_128_gcm", mode)) + session->tls_mode = KTLS_TLS_13_128_GCM; + else if (!strcmp("tls_12_256_gcm", mode)) + session->tls_mode = KTLS_TLS_12_256_GCM; + else { + error("unknown tls mode: %s", mode); + return EXIT_FAILURE; + } + return EXIT_SUCCESS; +} + +#define INIT_GCM_WITH_MODE(V, X) \ + { \ + struct tls12_crypto_info_aes_gcm_##X crypto_info; \ +\ + crypto_info.info.version = TLS_##V##_VERSION; \ + crypto_info.info.cipher_type = TLS_CIPHER_AES_GCM_##X; \ + memcpy(crypto_info.iv, seq_number, \ + TLS_CIPHER_AES_GCM_##X##_IV_SIZE); \ + memcpy(crypto_info.rec_seq, seq_number, \ + TLS_CIPHER_AES_GCM_##X##_REC_SEQ_SIZE); \ + if (cipher_key.size != TLS_CIPHER_AES_GCM_##X##_KEY_SIZE) { \ + error("mismatch in send key size: %d != %d\n", \ + cipher_key.size, \ + TLS_CIPHER_AES_GCM_##X##_KEY_SIZE); \ + goto cleanup; \ + } \ + memcpy(crypto_info.key, cipher_key.data, \ + TLS_CIPHER_AES_GCM_##X##_KEY_SIZE); \ + memcpy(crypto_info.salt, iv.data, \ + TLS_CIPHER_AES_GCM_##X##_SALT_SIZE); \ + if (setsockopt(sock, SOL_TLS, is_sender ? TLS_TX : TLS_RX, \ + &crypto_info, sizeof(crypto_info))) { \ + error("fail to set kernel tls: %s", strerror(errno)); \ + goto cleanup; \ + } \ + } + +int ktls_handshake_tls(struct ktls_session *session, int sock) +{ + int rc = 0; + bool is_sender = false; + int handshake_retry = 3; + char tls_priority_list[KTLS_MAX_PRIORITY_STRING_LENTH]; + const char *tls_priority_templ = + "NONE:+MAC-ALL:+COMP-NULL:+SIGN-ALL:+GROUP-ALL:+ECDHE-PSK:+DHE-PSK:%s:%s"; + const char *tls_priority_ver_mode = NULL; + + gnutls_datum_t mac_key; + gnutls_datum_t iv; + gnutls_datum_t cipher_key; + unsigned char seq_number[8]; + + if (!session || !session->session) + return EXIT_FAILURE; + + switch (session->tls_mode) { + case KTLS_TLS_MODE_NONE: + return EXIT_SUCCESS; + case KTLS_TLS_12_128_GCM: + tls_priority_ver_mode = "+VERS-TLS1.2:+AES-128-GCM"; + break; + case KTLS_TLS_13_128_GCM: + tls_priority_ver_mode = "+VERS-TLS1.3:+AES-128-GCM"; + break; + case KTLS_TLS_12_256_GCM: + tls_priority_ver_mode = "+VERS-TLS1.2:+AES-256-GCM"; + break; + default: + error("unknown tls mode"); + goto cleanup; + } + + is_sender = session->role == GNUTLS_CLIENT; + + if (is_sender && session->psk_cred_client) { + rc = gnutls_credentials_set(session->session, GNUTLS_CRD_PSK, + session->psk_cred_client); + if (rc != GNUTLS_E_SUCCESS) { + error("fail to set PSK for client: %s", + gnutls_strerror(rc)); + goto cleanup; + } + } + + if (!is_sender && session->psk_cred_server) { + rc = gnutls_credentials_set(session->session, GNUTLS_CRD_PSK, + session->psk_cred_server); + if (rc != GNUTLS_E_SUCCESS) { + error("fail to set PSK for server: %s", + gnutls_strerror(rc)); + goto cleanup; + } + } + + if (session->crt_cred) { + rc = gnutls_credentials_set(session->session, + GNUTLS_CRD_CERTIFICATE, + session->crt_cred); + + if (rc == GNUTLS_E_SUCCESS) { + error("fail to set certificate: %s", + gnutls_strerror(rc)); + goto cleanup; + } + } + + snprintf(tls_priority_list, KTLS_MAX_PRIORITY_STRING_LENTH, + tls_priority_templ, + is_sender ? "+CTYPE-CLI-ALL" : "+CTYPE-SRV-ALL", + tls_priority_ver_mode); + + rc = gnutls_priority_set_direct(session->session, tls_priority_list, + NULL); + if (rc != GNUTLS_E_SUCCESS) { + error("fail to set priority: %s", gnutls_strerror(rc)); + goto cleanup; + } + + gnutls_transport_set_int(session->session, sock); + + gnutls_handshake_set_timeout(session->session, + GNUTLS_DEFAULT_HANDSHAKE_TIMEOUT); + + do { + if (handshake_retry < 0) { + error("exhaust retries on handshake"); + break; + } + rc = gnutls_handshake(session->session); + handshake_retry--; + } while (rc < 0 && !gnutls_error_is_fatal(rc)); + + if (gnutls_error_is_fatal(rc)) { + error("fail on handshake: %s", gnutls_strerror(rc)); + goto cleanup; + } + if (bconf.verbose > 0) { + char *desc = gnutls_session_get_desc(session->session); + + printf("TLS session info: %s\n", desc); + gnutls_free(desc); + } + + session->stage = KTLS_STAGE_HAS_HANDSHAKED; + + rc = gnutls_record_get_state(session->session, is_sender ? 0 : 1, + &mac_key, &iv, &cipher_key, seq_number); + if (rc != GNUTLS_E_SUCCESS) { + error("fail on retrieve TLS record: %s", gnutls_strerror(rc)); + goto cleanup; + } + + if (setsockopt(sock, SOL_TCP, TCP_ULP, "tls", sizeof("tls"))) { + error("fail to set kernel TLS on socket: %s", strerror(errno)); + goto cleanup; + } + + switch (session->tls_mode) { + case KTLS_TLS_12_128_GCM: + INIT_GCM_WITH_MODE(1_2, 128); + break; + case KTLS_TLS_13_128_GCM: + INIT_GCM_WITH_MODE(1_3, 128); + break; + case KTLS_TLS_12_256_GCM: + INIT_GCM_WITH_MODE(1_2, 256); + break; + default: + error("unknown tls mode"); + goto cleanup; + } + + if (bconf.verbose > 0) + fprintf(stderr, "ktls init done\n"); + + return EXIT_SUCCESS; + +cleanup: + return EXIT_FAILURE; +} + +static int ktls_cp_datum(gnutls_datum_t *to, const gnutls_datum_t *from) +{ + if (!to || !from) + return EXIT_FAILURE; + + to->size = from->size; + to->data = (unsigned char *)gnutls_malloc(to->size); + memmove(to->data, from->data, to->size); + + return EXIT_SUCCESS; +} + +static int ktls_cmp_datum(const gnutls_datum_t *lhs, const gnutls_datum_t *rhs) +{ + if (!lhs && !rhs) + return EXIT_SUCCESS; + + if (!lhs || !rhs) + return EXIT_FAILURE; + + if (lhs->size != rhs->size) + return EXIT_FAILURE; + + return memcmp(lhs->data, rhs->data, lhs->size); +} + +static int ktls_set_datum(gnutls_datum_t *to, const unsigned char *from, + int from_size) +{ + if (!to || !from || !from_size) + return EXIT_FAILURE; + + if (from_size < 0) + from_size = strlen((const char *)from); + + to->size = from_size; + to->data = (unsigned char *)gnutls_malloc(to->size); + memmove(to->data, from, from_size); + + return EXIT_SUCCESS; +} + +static int tls_psk_client_callback(gnutls_session_t session, + gnutls_datum_t *username, + gnutls_datum_t *key) +{ + if (ktls_cp_datum(username, &ktls_psk_username) || + ktls_cp_datum(key, &ktls_psk_key)) + return EXIT_FAILURE; + + return EXIT_SUCCESS; +} + +static int tls_psk_server_callback(gnutls_session_t session, + const gnutls_datum_t *username, + gnutls_datum_t *key) +{ + if (ktls_cmp_datum(username, &ktls_psk_username) || + ktls_cp_datum(key, &ktls_psk_key)) + return EXIT_FAILURE; + + return EXIT_SUCCESS; +} + +int ktls_set_psk_session(struct ktls_session *session, const char *username, + const unsigned char *passwd, const size_t sz_passwd) +{ + bool is_sender = false; + int rc = 0; + + if (!session || !session->session) + goto cleanup; + + is_sender = session->role == GNUTLS_CLIENT; + + if (!is_sender && !session->psk_cred_server) { + rc = gnutls_psk_allocate_server_credentials( + &session->psk_cred_server); + if (rc != GNUTLS_E_SUCCESS) { + error("fail on set psk for server: %s", + gnutls_strerror(rc)); + goto cleanup; + } + gnutls_psk_set_server_credentials_function2( + session->psk_cred_server, tls_psk_server_callback); + } + + if (is_sender && !session->psk_cred_client) { + rc = gnutls_psk_allocate_client_credentials( + &session->psk_cred_client); + if (rc != GNUTLS_E_SUCCESS) { + error("fail on set psk for client: %s", + gnutls_strerror(rc)); + goto cleanup; + } + gnutls_psk_set_client_credentials_function2( + session->psk_cred_client, tls_psk_client_callback); + } + + if (!ktls_psk_key.size) + gnutls_free(ktls_psk_key.data); + + if (!ktls_psk_username.size) + gnutls_free(ktls_psk_username.data); + + if (ktls_set_datum(&ktls_psk_username, (const unsigned char *)username, + -1) || + ktls_set_datum(&ktls_psk_key, passwd, sz_passwd)) + goto cleanup; + + return EXIT_SUCCESS; + +cleanup: + return EXIT_FAILURE; +} + +int ktls_create_sock_oneshot(struct ktls_session *session, const char *host, + const char *port) +{ + int sock = 0; + int nport = 0; + bool is_sender; + + if (!session || !session->session) + return EXIT_FAILURE; + + is_sender = session->role == GNUTLS_CLIENT; + + nport = atoi(port); + + if (nport >= 0 && nport <= 65535) + nport = htons((uint16_t)nport); + + if (ktls_connect_ip(&sock, is_sender, host, (uint16_t)nport)) + if (ktls_connect_domain(&sock, is_sender, host, nport)) + goto cleanup; + + if (!is_sender) { + int accepted_sock = KTLS_INVALID_FD; + + accepted_sock = accept(sock, (struct sockaddr *)NULL, NULL); + close(sock); + sock = accepted_sock; + } + + if (ktls_handshake_tls(session, sock)) + goto cleanup; + + return sock; + +cleanup: + close(sock); + return KTLS_INVALID_FD; +} diff --git a/common/ktls.h b/common/ktls.h new file mode 100644 index 00000000..d744e18e --- /dev/null +++ b/common/ktls.h @@ -0,0 +1,57 @@ +/* + * Copyright (C) 2020 Sheng Mao. All rights reserved. + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public + * License v2 as published by the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * General Public License for more details. + */ + +#ifndef __BTRFS_KTLS_H__ +#define __BTRFS_KTLS_H__ + +#include +#include + +#ifdef __cplusplus +extern "C" { +#endif + +struct ktls_session; + +enum { KTLS_INVALID_FD = -1 }; + +struct ktls_session *ktls_create_session(bool is_sender); +void ktls_destroy_session(struct ktls_session *session); + +// ktls_set_psk_session sets PSK (pre-shared key). username is NULL-terminated +// string; passwd is sized string. Memory of both strings are managed by +// caller. currently, this API only allows to set PSK before calling +// ktls_handshake_*() +int ktls_set_psk_session(struct ktls_session *session, const char *username, + const unsigned char *passwd, const size_t sz_passwd); + +int ktls_set_psk_session_from_password_prompt(struct ktls_session *session, + const char *username); + +int ktls_set_psk_session_from_keyfile(struct ktls_session *session, + const char *username, + const char *key_file); + +int ktls_set_tls_mode(struct ktls_session *session, const char *mode); + +int ktls_handshake_tls(struct ktls_session *session, int sock); + +// ktls_create_sock_oneshot returns a sock fd on success. +int ktls_create_sock_oneshot(struct ktls_session *session, const char *host, + const char *port); + +#ifdef __cplusplus +} +#endif + +#endif // __BTRFS_KTLS_H__ -- 2.29.2