| /* |
| * Copyright 1999-2021 The OpenSSL Project Authors. All Rights Reserved. |
| * |
| * Licensed under the Apache License 2.0 (the "License"). You may not use |
| * this file except in compliance with the License. You can obtain a copy |
| * in the file LICENSE in the source distribution or at |
| * https://www.openssl.org/source/license.html |
| */ |
| |
| /* |
| * Special method for a BIO where the other endpoint is also a BIO of this |
| * kind, handled by the same thread (i.e. the "peer" is actually ourselves, |
| * wearing a different hat). Such "BIO pairs" are mainly for using the SSL |
| * library with I/O interfaces for which no specific BIO method is available. |
| * See ssl/ssltest.c for some hints on how this can be used. |
| */ |
| |
| #include "internal/e_os.h" |
| #include <assert.h> |
| #include <limits.h> |
| #include <stdlib.h> |
| #include <string.h> |
| |
| #include "bio_local.h" |
| #include <openssl/err.h> |
| #include <openssl/crypto.h> |
| |
| static int bio_new(BIO *bio); |
| static int bio_free(BIO *bio); |
| static int bio_read(BIO *bio, char *buf, int size); |
| static int bio_write(BIO *bio, const char *buf, int num); |
| static long bio_ctrl(BIO *bio, int cmd, long num, void *ptr); |
| static int bio_puts(BIO *bio, const char *str); |
| |
| static int bio_make_pair(BIO *bio1, BIO *bio2); |
| static void bio_destroy_pair(BIO *bio); |
| |
| static const BIO_METHOD methods_biop = { |
| BIO_TYPE_BIO, |
| "BIO pair", |
| bwrite_conv, |
| bio_write, |
| bread_conv, |
| bio_read, |
| bio_puts, |
| NULL /* no bio_gets */ , |
| bio_ctrl, |
| bio_new, |
| bio_free, |
| NULL /* no bio_callback_ctrl */ |
| }; |
| |
| const BIO_METHOD *BIO_s_bio(void) |
| { |
| return &methods_biop; |
| } |
| |
| struct bio_bio_st { |
| BIO *peer; /* NULL if buf == NULL. If peer != NULL, then |
| * peer->ptr is also a bio_bio_st, and its |
| * "peer" member points back to us. peer != |
| * NULL iff init != 0 in the BIO. */ |
| /* This is for what we write (i.e. reading uses peer's struct): */ |
| int closed; /* valid iff peer != NULL */ |
| size_t len; /* valid iff buf != NULL; 0 if peer == NULL */ |
| size_t offset; /* valid iff buf != NULL; 0 if len == 0 */ |
| size_t size; |
| char *buf; /* "size" elements (if != NULL) */ |
| size_t request; /* valid iff peer != NULL; 0 if len != 0, |
| * otherwise set by peer to number of bytes |
| * it (unsuccessfully) tried to read, never |
| * more than buffer space (size-len) |
| * warrants. */ |
| }; |
| |
| static int bio_new(BIO *bio) |
| { |
| struct bio_bio_st *b = OPENSSL_zalloc(sizeof(*b)); |
| |
| if (b == NULL) |
| return 0; |
| |
| /* enough for one TLS record (just a default) */ |
| b->size = 17 * 1024; |
| |
| bio->ptr = b; |
| return 1; |
| } |
| |
| static int bio_free(BIO *bio) |
| { |
| struct bio_bio_st *b; |
| |
| if (bio == NULL) |
| return 0; |
| b = bio->ptr; |
| |
| assert(b != NULL); |
| |
| if (b->peer) |
| bio_destroy_pair(bio); |
| |
| OPENSSL_free(b->buf); |
| OPENSSL_free(b); |
| |
| return 1; |
| } |
| |
| static int bio_read(BIO *bio, char *buf, int size_) |
| { |
| size_t size = size_; |
| size_t rest; |
| struct bio_bio_st *b, *peer_b; |
| |
| BIO_clear_retry_flags(bio); |
| |
| if (!bio->init) |
| return 0; |
| |
| b = bio->ptr; |
| assert(b != NULL); |
| assert(b->peer != NULL); |
| peer_b = b->peer->ptr; |
| assert(peer_b != NULL); |
| assert(peer_b->buf != NULL); |
| |
| peer_b->request = 0; /* will be set in "retry_read" situation */ |
| |
| if (buf == NULL || size == 0) |
| return 0; |
| |
| if (peer_b->len == 0) { |
| if (peer_b->closed) |
| return 0; /* writer has closed, and no data is left */ |
| else { |
| BIO_set_retry_read(bio); /* buffer is empty */ |
| if (size <= peer_b->size) |
| peer_b->request = size; |
| else |
| /* |
| * don't ask for more than the peer can deliver in one write |
| */ |
| peer_b->request = peer_b->size; |
| return -1; |
| } |
| } |
| |
| /* we can read */ |
| if (peer_b->len < size) |
| size = peer_b->len; |
| |
| /* now read "size" bytes */ |
| |
| rest = size; |
| |
| assert(rest > 0); |
| do { /* one or two iterations */ |
| size_t chunk; |
| |
| assert(rest <= peer_b->len); |
| if (peer_b->offset + rest <= peer_b->size) |
| chunk = rest; |
| else |
| /* wrap around ring buffer */ |
| chunk = peer_b->size - peer_b->offset; |
| assert(peer_b->offset + chunk <= peer_b->size); |
| |
| memcpy(buf, peer_b->buf + peer_b->offset, chunk); |
| |
| peer_b->len -= chunk; |
| if (peer_b->len) { |
| peer_b->offset += chunk; |
| assert(peer_b->offset <= peer_b->size); |
| if (peer_b->offset == peer_b->size) |
| peer_b->offset = 0; |
| buf += chunk; |
| } else { |
| /* buffer now empty, no need to advance "buf" */ |
| assert(chunk == rest); |
| peer_b->offset = 0; |
| } |
| rest -= chunk; |
| } |
| while (rest); |
| |
| return size; |
| } |
| |
| /*- |
| * non-copying interface: provide pointer to available data in buffer |
| * bio_nread0: return number of available bytes |
| * bio_nread: also advance index |
| * (example usage: bio_nread0(), read from buffer, bio_nread() |
| * or just bio_nread(), read from buffer) |
| */ |
| /* |
| * WARNING: The non-copying interface is largely untested as of yet and may |
| * contain bugs. |
| */ |
| static ossl_ssize_t bio_nread0(BIO *bio, char **buf) |
| { |
| struct bio_bio_st *b, *peer_b; |
| ossl_ssize_t num; |
| |
| BIO_clear_retry_flags(bio); |
| |
| if (!bio->init) |
| return 0; |
| |
| b = bio->ptr; |
| assert(b != NULL); |
| assert(b->peer != NULL); |
| peer_b = b->peer->ptr; |
| assert(peer_b != NULL); |
| assert(peer_b->buf != NULL); |
| |
| peer_b->request = 0; |
| |
| if (peer_b->len == 0) { |
| char dummy; |
| |
| /* avoid code duplication -- nothing available for reading */ |
| return bio_read(bio, &dummy, 1); /* returns 0 or -1 */ |
| } |
| |
| num = peer_b->len; |
| if (peer_b->size < peer_b->offset + num) |
| /* no ring buffer wrap-around for non-copying interface */ |
| num = peer_b->size - peer_b->offset; |
| assert(num > 0); |
| |
| if (buf != NULL) |
| *buf = peer_b->buf + peer_b->offset; |
| return num; |
| } |
| |
| static ossl_ssize_t bio_nread(BIO *bio, char **buf, size_t num_) |
| { |
| struct bio_bio_st *b, *peer_b; |
| ossl_ssize_t num, available; |
| |
| if (num_ > OSSL_SSIZE_MAX) |
| num = OSSL_SSIZE_MAX; |
| else |
| num = (ossl_ssize_t) num_; |
| |
| available = bio_nread0(bio, buf); |
| if (num > available) |
| num = available; |
| if (num <= 0) |
| return num; |
| |
| b = bio->ptr; |
| peer_b = b->peer->ptr; |
| |
| peer_b->len -= num; |
| if (peer_b->len) { |
| peer_b->offset += num; |
| assert(peer_b->offset <= peer_b->size); |
| if (peer_b->offset == peer_b->size) |
| peer_b->offset = 0; |
| } else |
| peer_b->offset = 0; |
| |
| return num; |
| } |
| |
| static int bio_write(BIO *bio, const char *buf, int num_) |
| { |
| size_t num = num_; |
| size_t rest; |
| struct bio_bio_st *b; |
| |
| BIO_clear_retry_flags(bio); |
| |
| if (!bio->init || buf == NULL || num_ <= 0) |
| return 0; |
| |
| b = bio->ptr; |
| assert(b != NULL); |
| assert(b->peer != NULL); |
| assert(b->buf != NULL); |
| |
| b->request = 0; |
| if (b->closed) { |
| /* we already closed */ |
| ERR_raise(ERR_LIB_BIO, BIO_R_BROKEN_PIPE); |
| return -1; |
| } |
| |
| assert(b->len <= b->size); |
| |
| if (b->len == b->size) { |
| BIO_set_retry_write(bio); /* buffer is full */ |
| return -1; |
| } |
| |
| /* we can write */ |
| if (num > b->size - b->len) |
| num = b->size - b->len; |
| |
| /* now write "num" bytes */ |
| |
| rest = num; |
| |
| assert(rest > 0); |
| do { /* one or two iterations */ |
| size_t write_offset; |
| size_t chunk; |
| |
| assert(b->len + rest <= b->size); |
| |
| write_offset = b->offset + b->len; |
| if (write_offset >= b->size) |
| write_offset -= b->size; |
| /* b->buf[write_offset] is the first byte we can write to. */ |
| |
| if (write_offset + rest <= b->size) |
| chunk = rest; |
| else |
| /* wrap around ring buffer */ |
| chunk = b->size - write_offset; |
| |
| memcpy(b->buf + write_offset, buf, chunk); |
| |
| b->len += chunk; |
| |
| assert(b->len <= b->size); |
| |
| rest -= chunk; |
| buf += chunk; |
| } |
| while (rest); |
| |
| return num; |
| } |
| |
| /*- |
| * non-copying interface: provide pointer to region to write to |
| * bio_nwrite0: check how much space is available |
| * bio_nwrite: also increase length |
| * (example usage: bio_nwrite0(), write to buffer, bio_nwrite() |
| * or just bio_nwrite(), write to buffer) |
| */ |
| static ossl_ssize_t bio_nwrite0(BIO *bio, char **buf) |
| { |
| struct bio_bio_st *b; |
| size_t num; |
| size_t write_offset; |
| |
| BIO_clear_retry_flags(bio); |
| |
| if (!bio->init) |
| return 0; |
| |
| b = bio->ptr; |
| assert(b != NULL); |
| assert(b->peer != NULL); |
| assert(b->buf != NULL); |
| |
| b->request = 0; |
| if (b->closed) { |
| ERR_raise(ERR_LIB_BIO, BIO_R_BROKEN_PIPE); |
| return -1; |
| } |
| |
| assert(b->len <= b->size); |
| |
| if (b->len == b->size) { |
| BIO_set_retry_write(bio); |
| return -1; |
| } |
| |
| num = b->size - b->len; |
| write_offset = b->offset + b->len; |
| if (write_offset >= b->size) |
| write_offset -= b->size; |
| if (write_offset + num > b->size) |
| /* |
| * no ring buffer wrap-around for non-copying interface (to fulfil |
| * the promise by BIO_ctrl_get_write_guarantee, BIO_nwrite may have |
| * to be called twice) |
| */ |
| num = b->size - write_offset; |
| |
| if (buf != NULL) |
| *buf = b->buf + write_offset; |
| assert(write_offset + num <= b->size); |
| |
| return num; |
| } |
| |
| static ossl_ssize_t bio_nwrite(BIO *bio, char **buf, size_t num_) |
| { |
| struct bio_bio_st *b; |
| ossl_ssize_t num, space; |
| |
| if (num_ > OSSL_SSIZE_MAX) |
| num = OSSL_SSIZE_MAX; |
| else |
| num = (ossl_ssize_t) num_; |
| |
| space = bio_nwrite0(bio, buf); |
| if (num > space) |
| num = space; |
| if (num <= 0) |
| return num; |
| b = bio->ptr; |
| assert(b != NULL); |
| b->len += num; |
| assert(b->len <= b->size); |
| |
| return num; |
| } |
| |
| static long bio_ctrl(BIO *bio, int cmd, long num, void *ptr) |
| { |
| long ret; |
| struct bio_bio_st *b = bio->ptr; |
| |
| assert(b != NULL); |
| |
| switch (cmd) { |
| /* specific CTRL codes */ |
| |
| case BIO_C_SET_WRITE_BUF_SIZE: |
| if (b->peer) { |
| ERR_raise(ERR_LIB_BIO, BIO_R_IN_USE); |
| ret = 0; |
| } else if (num == 0) { |
| ERR_raise(ERR_LIB_BIO, BIO_R_INVALID_ARGUMENT); |
| ret = 0; |
| } else { |
| size_t new_size = num; |
| |
| if (b->size != new_size) { |
| OPENSSL_free(b->buf); |
| b->buf = NULL; |
| b->size = new_size; |
| } |
| ret = 1; |
| } |
| break; |
| |
| case BIO_C_GET_WRITE_BUF_SIZE: |
| ret = (long)b->size; |
| break; |
| |
| case BIO_C_MAKE_BIO_PAIR: |
| { |
| BIO *other_bio = ptr; |
| |
| if (bio_make_pair(bio, other_bio)) |
| ret = 1; |
| else |
| ret = 0; |
| } |
| break; |
| |
| case BIO_C_DESTROY_BIO_PAIR: |
| /* |
| * Affects both BIOs in the pair -- call just once! Or let |
| * BIO_free(bio1); BIO_free(bio2); do the job. |
| */ |
| bio_destroy_pair(bio); |
| ret = 1; |
| break; |
| |
| case BIO_C_GET_WRITE_GUARANTEE: |
| /* |
| * How many bytes can the caller feed to the next write without |
| * having to keep any? |
| */ |
| if (b->peer == NULL || b->closed) |
| ret = 0; |
| else |
| ret = (long)b->size - b->len; |
| break; |
| |
| case BIO_C_GET_READ_REQUEST: |
| /* |
| * If the peer unsuccessfully tried to read, how many bytes were |
| * requested? (As with BIO_CTRL_PENDING, that number can usually be |
| * treated as boolean.) |
| */ |
| ret = (long)b->request; |
| break; |
| |
| case BIO_C_RESET_READ_REQUEST: |
| /* |
| * Reset request. (Can be useful after read attempts at the other |
| * side that are meant to be non-blocking, e.g. when probing SSL_read |
| * to see if any data is available.) |
| */ |
| b->request = 0; |
| ret = 1; |
| break; |
| |
| case BIO_C_SHUTDOWN_WR: |
| /* similar to shutdown(..., SHUT_WR) */ |
| b->closed = 1; |
| ret = 1; |
| break; |
| |
| case BIO_C_NREAD0: |
| /* prepare for non-copying read */ |
| ret = (long)bio_nread0(bio, ptr); |
| break; |
| |
| case BIO_C_NREAD: |
| /* non-copying read */ |
| ret = (long)bio_nread(bio, ptr, (size_t)num); |
| break; |
| |
| case BIO_C_NWRITE0: |
| /* prepare for non-copying write */ |
| ret = (long)bio_nwrite0(bio, ptr); |
| break; |
| |
| case BIO_C_NWRITE: |
| /* non-copying write */ |
| ret = (long)bio_nwrite(bio, ptr, (size_t)num); |
| break; |
| |
| /* standard CTRL codes follow */ |
| |
| case BIO_CTRL_RESET: |
| if (b->buf != NULL) { |
| b->len = 0; |
| b->offset = 0; |
| } |
| ret = 0; |
| break; |
| |
| case BIO_CTRL_GET_CLOSE: |
| ret = bio->shutdown; |
| break; |
| |
| case BIO_CTRL_SET_CLOSE: |
| bio->shutdown = (int)num; |
| ret = 1; |
| break; |
| |
| case BIO_CTRL_PENDING: |
| if (b->peer != NULL) { |
| struct bio_bio_st *peer_b = b->peer->ptr; |
| |
| ret = (long)peer_b->len; |
| } else |
| ret = 0; |
| break; |
| |
| case BIO_CTRL_WPENDING: |
| if (b->buf != NULL) |
| ret = (long)b->len; |
| else |
| ret = 0; |
| break; |
| |
| case BIO_CTRL_DUP: |
| /* See BIO_dup_chain for circumstances we have to expect. */ |
| { |
| BIO *other_bio = ptr; |
| struct bio_bio_st *other_b; |
| |
| assert(other_bio != NULL); |
| other_b = other_bio->ptr; |
| assert(other_b != NULL); |
| |
| assert(other_b->buf == NULL); /* other_bio is always fresh */ |
| |
| other_b->size = b->size; |
| } |
| |
| ret = 1; |
| break; |
| |
| case BIO_CTRL_FLUSH: |
| ret = 1; |
| break; |
| |
| case BIO_CTRL_EOF: |
| if (b->peer != NULL) { |
| struct bio_bio_st *peer_b = b->peer->ptr; |
| |
| if (peer_b->len == 0 && peer_b->closed) |
| ret = 1; |
| else |
| ret = 0; |
| } else { |
| ret = 1; |
| } |
| break; |
| |
| default: |
| ret = 0; |
| } |
| return ret; |
| } |
| |
| static int bio_puts(BIO *bio, const char *str) |
| { |
| return bio_write(bio, str, strlen(str)); |
| } |
| |
| static int bio_make_pair(BIO *bio1, BIO *bio2) |
| { |
| struct bio_bio_st *b1, *b2; |
| |
| assert(bio1 != NULL); |
| assert(bio2 != NULL); |
| |
| b1 = bio1->ptr; |
| b2 = bio2->ptr; |
| |
| if (b1->peer != NULL || b2->peer != NULL) { |
| ERR_raise(ERR_LIB_BIO, BIO_R_IN_USE); |
| return 0; |
| } |
| |
| if (b1->buf == NULL) { |
| b1->buf = OPENSSL_malloc(b1->size); |
| if (b1->buf == NULL) { |
| ERR_raise(ERR_LIB_BIO, ERR_R_MALLOC_FAILURE); |
| return 0; |
| } |
| b1->len = 0; |
| b1->offset = 0; |
| } |
| |
| if (b2->buf == NULL) { |
| b2->buf = OPENSSL_malloc(b2->size); |
| if (b2->buf == NULL) { |
| ERR_raise(ERR_LIB_BIO, ERR_R_MALLOC_FAILURE); |
| return 0; |
| } |
| b2->len = 0; |
| b2->offset = 0; |
| } |
| |
| b1->peer = bio2; |
| b1->closed = 0; |
| b1->request = 0; |
| b2->peer = bio1; |
| b2->closed = 0; |
| b2->request = 0; |
| |
| bio1->init = 1; |
| bio2->init = 1; |
| |
| return 1; |
| } |
| |
| static void bio_destroy_pair(BIO *bio) |
| { |
| struct bio_bio_st *b = bio->ptr; |
| |
| if (b != NULL) { |
| BIO *peer_bio = b->peer; |
| |
| if (peer_bio != NULL) { |
| struct bio_bio_st *peer_b = peer_bio->ptr; |
| |
| assert(peer_b != NULL); |
| assert(peer_b->peer == bio); |
| |
| peer_b->peer = NULL; |
| peer_bio->init = 0; |
| assert(peer_b->buf != NULL); |
| peer_b->len = 0; |
| peer_b->offset = 0; |
| |
| b->peer = NULL; |
| bio->init = 0; |
| assert(b->buf != NULL); |
| b->len = 0; |
| b->offset = 0; |
| } |
| } |
| } |
| |
| /* Exported convenience functions */ |
| int BIO_new_bio_pair(BIO **bio1_p, size_t writebuf1, |
| BIO **bio2_p, size_t writebuf2) |
| { |
| BIO *bio1 = NULL, *bio2 = NULL; |
| long r; |
| int ret = 0; |
| |
| bio1 = BIO_new(BIO_s_bio()); |
| if (bio1 == NULL) |
| goto err; |
| bio2 = BIO_new(BIO_s_bio()); |
| if (bio2 == NULL) |
| goto err; |
| |
| if (writebuf1) { |
| r = BIO_set_write_buf_size(bio1, writebuf1); |
| if (!r) |
| goto err; |
| } |
| if (writebuf2) { |
| r = BIO_set_write_buf_size(bio2, writebuf2); |
| if (!r) |
| goto err; |
| } |
| |
| r = BIO_make_bio_pair(bio1, bio2); |
| if (!r) |
| goto err; |
| ret = 1; |
| |
| err: |
| if (ret == 0) { |
| BIO_free(bio1); |
| bio1 = NULL; |
| BIO_free(bio2); |
| bio2 = NULL; |
| } |
| |
| *bio1_p = bio1; |
| *bio2_p = bio2; |
| return ret; |
| } |
| |
| size_t BIO_ctrl_get_write_guarantee(BIO *bio) |
| { |
| return BIO_ctrl(bio, BIO_C_GET_WRITE_GUARANTEE, 0, NULL); |
| } |
| |
| size_t BIO_ctrl_get_read_request(BIO *bio) |
| { |
| return BIO_ctrl(bio, BIO_C_GET_READ_REQUEST, 0, NULL); |
| } |
| |
| int BIO_ctrl_reset_read_request(BIO *bio) |
| { |
| return (BIO_ctrl(bio, BIO_C_RESET_READ_REQUEST, 0, NULL) != 0); |
| } |
| |
| /* |
| * BIO_nread0/nread/nwrite0/nwrite are available only for BIO pairs for now |
| * (conceivably some other BIOs could allow non-copying reads and writes |
| * too.) |
| */ |
| int BIO_nread0(BIO *bio, char **buf) |
| { |
| long ret; |
| |
| if (!bio->init) { |
| ERR_raise(ERR_LIB_BIO, BIO_R_UNINITIALIZED); |
| return -2; |
| } |
| |
| ret = BIO_ctrl(bio, BIO_C_NREAD0, 0, buf); |
| if (ret > INT_MAX) |
| return INT_MAX; |
| else |
| return (int)ret; |
| } |
| |
| int BIO_nread(BIO *bio, char **buf, int num) |
| { |
| int ret; |
| |
| if (!bio->init) { |
| ERR_raise(ERR_LIB_BIO, BIO_R_UNINITIALIZED); |
| return -2; |
| } |
| |
| ret = (int)BIO_ctrl(bio, BIO_C_NREAD, num, buf); |
| if (ret > 0) |
| bio->num_read += ret; |
| return ret; |
| } |
| |
| int BIO_nwrite0(BIO *bio, char **buf) |
| { |
| long ret; |
| |
| if (!bio->init) { |
| ERR_raise(ERR_LIB_BIO, BIO_R_UNINITIALIZED); |
| return -2; |
| } |
| |
| ret = BIO_ctrl(bio, BIO_C_NWRITE0, 0, buf); |
| if (ret > INT_MAX) |
| return INT_MAX; |
| else |
| return (int)ret; |
| } |
| |
| int BIO_nwrite(BIO *bio, char **buf, int num) |
| { |
| int ret; |
| |
| if (!bio->init) { |
| ERR_raise(ERR_LIB_BIO, BIO_R_UNINITIALIZED); |
| return -2; |
| } |
| |
| ret = BIO_ctrl(bio, BIO_C_NWRITE, num, buf); |
| if (ret > 0) |
| bio->num_write += ret; |
| return ret; |
| } |
