commit 4e4c4e72d74d66181bec537fc00a8af92be0a0af Author: liberat liberat@disroot.org Date: Mon Nov 11 15:08:36 2019 +0000
Handle binary IPv6 addresses and bracketed strings in RESOLVE_PTR.
When a SOCKS5 client sends a RESOLVE_PTR request, it must include either an IPv4 or IPv6 address. In the past this was required to be a binary address (address types 1 or 4), but since the refactoring of SOCKS5 support in Tor 0.3.5.1-alpha, strings (address type 3) are also allowed if they represent an IPv4 or IPv6 literal.
However, when a binary IPv6 address is provided, parse_socks5_client_request converts it into a string enclosed in brackets. This doesn't match what string_is_valid_ipv6_address expects, so this would fail with the error "socks5 received RESOLVE_PTR command with hostname type. Rejecting."
By replacing string_is_valid_ipv4_address/string_is_valid_ipv6_address with tor_addr_parse, we accept strings both with and without brackets. This fixes the handling of binary addresses, and also improves symmetry with CONNECT and RESOLVE requests.
Fixes bug 32315. --- changes/bug32315 | 4 ++++ src/core/proto/proto_socks.c | 6 +++--- 2 files changed, 7 insertions(+), 3 deletions(-)
diff --git a/changes/bug32315 b/changes/bug32315 new file mode 100644 index 000000000..9b48d8259 --- /dev/null +++ b/changes/bug32315 @@ -0,0 +1,4 @@ + o Major bugfixes (networking): + - Correctly handle IPv6 addresses in SOCKS5 RESOLVE_PTR requests, + and accept strings as well as binary addresses. Fixes bug 32315; + bugfix on Tor 0.3.5.1-alpha. diff --git a/src/core/proto/proto_socks.c b/src/core/proto/proto_socks.c index 8b78ed44c..17f1fc0e5 100644 --- a/src/core/proto/proto_socks.c +++ b/src/core/proto/proto_socks.c @@ -615,6 +615,7 @@ process_socks5_client_request(socks_request_t *req, int safe_socks) { socks_result_t res = SOCKS_RESULT_DONE; + tor_addr_t tmpaddr;
if (req->command != SOCKS_COMMAND_CONNECT && req->command != SOCKS_COMMAND_RESOLVE && @@ -625,11 +626,10 @@ process_socks5_client_request(socks_request_t *req, }
if (req->command == SOCKS_COMMAND_RESOLVE_PTR && - !string_is_valid_ipv4_address(req->address) && - !string_is_valid_ipv6_address(req->address)) { + tor_addr_parse(&tmpaddr, req->address) < 0) { socks_request_set_socks5_error(req, SOCKS5_ADDRESS_TYPE_NOT_SUPPORTED); log_warn(LD_APP, "socks5 received RESOLVE_PTR command with " - "hostname type. Rejecting."); + "a malformed address. Rejecting.");
res = SOCKS_RESULT_INVALID; goto end;