| /* Copyright (c) 2015, Google Inc. |
| * |
| * Permission to use, copy, modify, and/or distribute this software for any |
| * purpose with or without fee is hereby granted, provided that the above |
| * copyright notice and this permission notice appear in all copies. |
| * |
| * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES |
| * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF |
| * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY |
| * SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES |
| * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION |
| * OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN |
| * CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. */ |
| |
| #include <openssl/ssl.h> |
| |
| #include <assert.h> |
| #include <limits.h> |
| #include <stdlib.h> |
| #include <string.h> |
| |
| #include <openssl/bio.h> |
| #include <openssl/err.h> |
| #include <openssl/mem.h> |
| #include <openssl/type_check.h> |
| |
| #include "internal.h" |
| |
| |
| OPENSSL_COMPILE_ASSERT(0xffff <= INT_MAX, uint16_fits_in_int); |
| |
| OPENSSL_COMPILE_ASSERT((SSL3_ALIGN_PAYLOAD & (SSL3_ALIGN_PAYLOAD - 1)) == 0, |
| align_to_a_power_of_two); |
| |
| /* setup_buffer initializes |buf| with capacity |cap|, aligned such that data |
| * written after |header_len| is aligned to a |SSL3_ALIGN_PAYLOAD|-byte |
| * boundary. It returns one on success and zero on error. */ |
| static int setup_buffer(SSL3_BUFFER *buf, size_t header_len, size_t cap) { |
| if (buf->buf != NULL || cap > 0xffff) { |
| OPENSSL_PUT_ERROR(SSL, ERR_R_INTERNAL_ERROR); |
| return 0; |
| } |
| |
| /* Add up to |SSL3_ALIGN_PAYLOAD| - 1 bytes of slack for alignment. */ |
| buf->buf = OPENSSL_malloc(cap + SSL3_ALIGN_PAYLOAD - 1); |
| if (buf->buf == NULL) { |
| OPENSSL_PUT_ERROR(SSL, ERR_R_MALLOC_FAILURE); |
| return 0; |
| } |
| |
| /* Arrange the buffer such that the record body is aligned. */ |
| buf->offset = (0 - header_len - (uintptr_t)buf->buf) & |
| (SSL3_ALIGN_PAYLOAD - 1); |
| buf->len = 0; |
| buf->cap = cap; |
| return 1; |
| } |
| |
| static void consume_buffer(SSL3_BUFFER *buf, size_t len) { |
| if (len > buf->len) { |
| abort(); |
| } |
| buf->offset += (uint16_t)len; |
| buf->len -= (uint16_t)len; |
| buf->cap -= (uint16_t)len; |
| } |
| |
| static void clear_buffer(SSL3_BUFFER *buf) { |
| OPENSSL_free(buf->buf); |
| memset(buf, 0, sizeof(SSL3_BUFFER)); |
| } |
| |
| OPENSSL_COMPILE_ASSERT(DTLS1_RT_HEADER_LENGTH + SSL3_RT_MAX_ENCRYPTED_LENGTH <= |
| 0xffff, |
| maximum_read_buffer_too_large); |
| |
| /* setup_read_buffer initializes the read buffer if not already initialized. It |
| * returns one on success and zero on failure. */ |
| static int setup_read_buffer(SSL *ssl) { |
| SSL3_BUFFER *buf = &ssl->s3->read_buffer; |
| |
| if (buf->buf != NULL) { |
| return 1; |
| } |
| |
| size_t header_len = ssl_record_prefix_len(ssl); |
| size_t cap = SSL3_RT_MAX_ENCRYPTED_LENGTH; |
| if (SSL_IS_DTLS(ssl)) { |
| cap += DTLS1_RT_HEADER_LENGTH; |
| } else { |
| cap += SSL3_RT_HEADER_LENGTH; |
| } |
| |
| return setup_buffer(buf, header_len, cap); |
| } |
| |
| uint8_t *ssl_read_buffer(SSL *ssl) { |
| return ssl->s3->read_buffer.buf + ssl->s3->read_buffer.offset; |
| } |
| |
| size_t ssl_read_buffer_len(const SSL *ssl) { |
| return ssl->s3->read_buffer.len; |
| } |
| |
| static int dtls_read_buffer_next_packet(SSL *ssl) { |
| SSL3_BUFFER *buf = &ssl->s3->read_buffer; |
| |
| if (buf->len > 0) { |
| /* It is an error to call |dtls_read_buffer_extend| when the read buffer is |
| * not empty. */ |
| OPENSSL_PUT_ERROR(SSL, ERR_R_INTERNAL_ERROR); |
| return -1; |
| } |
| |
| /* Read a single packet from |ssl->rbio|. |buf->cap| must fit in an int. */ |
| int ret = BIO_read(ssl->rbio, buf->buf + buf->offset, (int)buf->cap); |
| if (ret <= 0) { |
| ssl->rwstate = SSL_READING; |
| return ret; |
| } |
| /* |BIO_read| was bound by |buf->cap|, so this cannot overflow. */ |
| buf->len = (uint16_t)ret; |
| return 1; |
| } |
| |
| static int tls_read_buffer_extend_to(SSL *ssl, size_t len) { |
| SSL3_BUFFER *buf = &ssl->s3->read_buffer; |
| |
| if (len > buf->cap) { |
| OPENSSL_PUT_ERROR(SSL, SSL_R_BUFFER_TOO_SMALL); |
| return -1; |
| } |
| |
| /* Read until the target length is reached. */ |
| while (buf->len < len) { |
| /* The amount of data to read is bounded by |buf->cap|, which must fit in an |
| * int. */ |
| int ret = BIO_read(ssl->rbio, buf->buf + buf->offset + buf->len, |
| (int)(len - buf->len)); |
| if (ret <= 0) { |
| ssl->rwstate = SSL_READING; |
| return ret; |
| } |
| /* |BIO_read| was bound by |buf->cap - buf->len|, so this cannot |
| * overflow. */ |
| buf->len += (uint16_t)ret; |
| } |
| |
| return 1; |
| } |
| |
| int ssl_read_buffer_extend_to(SSL *ssl, size_t len) { |
| /* |ssl_read_buffer_extend_to| implicitly discards any consumed data. */ |
| ssl_read_buffer_discard(ssl); |
| |
| if (!setup_read_buffer(ssl)) { |
| return -1; |
| } |
| |
| if (ssl->rbio == NULL) { |
| OPENSSL_PUT_ERROR(SSL, SSL_R_BIO_NOT_SET); |
| return -1; |
| } |
| |
| ERR_clear_system_error(); |
| |
| int ret; |
| if (SSL_IS_DTLS(ssl)) { |
| /* |len| is ignored for a datagram transport. */ |
| ret = dtls_read_buffer_next_packet(ssl); |
| } else { |
| ret = tls_read_buffer_extend_to(ssl, len); |
| } |
| |
| if (ret <= 0) { |
| /* If the buffer was empty originally and remained empty after attempting to |
| * extend it, release the buffer until the next attempt. */ |
| ssl_read_buffer_discard(ssl); |
| } |
| return ret; |
| } |
| |
| void ssl_read_buffer_consume(SSL *ssl, size_t len) { |
| SSL3_BUFFER *buf = &ssl->s3->read_buffer; |
| |
| consume_buffer(buf, len); |
| if (!SSL_IS_DTLS(ssl)) { |
| /* The TLS stack never reads beyond the current record, so there will never |
| * be unconsumed data. If read-ahead is ever reimplemented, |
| * |ssl_read_buffer_discard| will require a |memcpy| to shift the excess |
| * back to the front of the buffer, to ensure there is enough space for the |
| * next record. */ |
| assert(buf->len == 0); |
| } |
| } |
| |
| void ssl_read_buffer_discard(SSL *ssl) { |
| if (ssl->s3->read_buffer.len == 0) { |
| ssl_read_buffer_clear(ssl); |
| } |
| } |
| |
| void ssl_read_buffer_clear(SSL *ssl) { |
| clear_buffer(&ssl->s3->read_buffer); |
| } |
| |
| |
| int ssl_write_buffer_is_pending(const SSL *ssl) { |
| return ssl->s3->write_buffer.len > 0; |
| } |
| |
| OPENSSL_COMPILE_ASSERT(SSL3_RT_HEADER_LENGTH * 2 + |
| SSL3_RT_SEND_MAX_ENCRYPTED_OVERHEAD * 2 + |
| SSL3_RT_MAX_PLAIN_LENGTH <= 0xffff, |
| maximum_tls_write_buffer_too_large); |
| |
| OPENSSL_COMPILE_ASSERT(DTLS1_RT_HEADER_LENGTH + |
| SSL3_RT_SEND_MAX_ENCRYPTED_OVERHEAD + |
| SSL3_RT_MAX_PLAIN_LENGTH <= 0xffff, |
| maximum_dtls_write_buffer_too_large); |
| |
| int ssl_write_buffer_init(SSL *ssl, uint8_t **out_ptr, size_t max_len) { |
| SSL3_BUFFER *buf = &ssl->s3->write_buffer; |
| |
| if (buf->buf != NULL) { |
| OPENSSL_PUT_ERROR(SSL, ERR_R_INTERNAL_ERROR); |
| return 0; |
| } |
| |
| size_t header_len = ssl_seal_prefix_len(ssl); |
| |
| /* TODO(davidben): This matches the original behavior in keeping the malloc |
| * size consistent. Does this matter? |cap| could just be |max_len|. */ |
| size_t cap = SSL3_RT_MAX_PLAIN_LENGTH + SSL3_RT_SEND_MAX_ENCRYPTED_OVERHEAD; |
| if (SSL_IS_DTLS(ssl)) { |
| cap += DTLS1_RT_HEADER_LENGTH; |
| } else { |
| cap += SSL3_RT_HEADER_LENGTH; |
| if (ssl->mode & SSL_MODE_CBC_RECORD_SPLITTING) { |
| cap += SSL3_RT_HEADER_LENGTH + SSL3_RT_SEND_MAX_ENCRYPTED_OVERHEAD; |
| } |
| } |
| |
| if (max_len > cap) { |
| OPENSSL_PUT_ERROR(SSL, SSL_R_BUFFER_TOO_SMALL); |
| return 0; |
| } |
| |
| if (!setup_buffer(buf, header_len, cap)) { |
| return 0; |
| } |
| *out_ptr = buf->buf + buf->offset; |
| return 1; |
| } |
| |
| void ssl_write_buffer_set_len(SSL *ssl, size_t len) { |
| SSL3_BUFFER *buf = &ssl->s3->write_buffer; |
| |
| if (len > buf->cap) { |
| abort(); |
| } |
| buf->len = len; |
| } |
| |
| static int tls_write_buffer_flush(SSL *ssl) { |
| SSL3_BUFFER *buf = &ssl->s3->write_buffer; |
| |
| while (buf->len > 0) { |
| int ret = BIO_write(ssl->wbio, buf->buf + buf->offset, buf->len); |
| if (ret <= 0) { |
| ssl->rwstate = SSL_WRITING; |
| return ret; |
| } |
| consume_buffer(buf, (size_t)ret); |
| } |
| ssl_write_buffer_clear(ssl); |
| return 1; |
| } |
| |
| static int dtls_write_buffer_flush(SSL *ssl) { |
| SSL3_BUFFER *buf = &ssl->s3->write_buffer; |
| if (buf->len == 0) { |
| return 1; |
| } |
| |
| int ret = BIO_write(ssl->wbio, buf->buf + buf->offset, buf->len); |
| if (ret <= 0) { |
| ssl->rwstate = SSL_WRITING; |
| /* If the write failed, drop the write buffer anyway. Datagram transports |
| * can't write half a packet, so the caller is expected to retry from the |
| * top. */ |
| ssl_write_buffer_clear(ssl); |
| return ret; |
| } |
| ssl_write_buffer_clear(ssl); |
| return 1; |
| } |
| |
| int ssl_write_buffer_flush(SSL *ssl) { |
| if (ssl->wbio == NULL) { |
| OPENSSL_PUT_ERROR(SSL, SSL_R_BIO_NOT_SET); |
| return -1; |
| } |
| ERR_clear_system_error(); |
| |
| if (SSL_IS_DTLS(ssl)) { |
| return dtls_write_buffer_flush(ssl); |
| } else { |
| return tls_write_buffer_flush(ssl); |
| } |
| } |
| |
| void ssl_write_buffer_clear(SSL *ssl) { |
| clear_buffer(&ssl->s3->write_buffer); |
| } |