commit f230beadf469e300c783791847a346c593033dd0 Author: George Kadianakis desnacked@riseup.net Date: Wed May 5 11:05:09 2021 +0300

Prepare for #40373: Re-introduce parsing for v2 onion addresses.

Welcome back ONION_V2_HOSTNAME! :) --- src/core/or/connection_edge.c | 28 +++++++++++++++++++++++++++- src/core/or/connection_edge.h | 1 + src/test/test_hs_common.c | 10 ++++++++++ 3 files changed, 38 insertions(+), 1 deletion(-)

diff --git a/src/core/or/connection_edge.c b/src/core/or/connection_edge.c index b89f3336dc..8e13161348 100644 --- a/src/core/or/connection_edge.c +++ b/src/core/or/connection_edge.c @@ -1612,6 +1612,23 @@ consider_plaintext_ports(entry_connection_t *conn, uint16_t port) return 0; }

+/** Return true iff <b>query</b> is a syntactically valid service ID (as + * generated by rend_get_service_id). */ +static int +rend_valid_v2_service_id(const char *query) +{ + /** Length of 'y' portion of 'y.onion' URL. */ +#define REND_SERVICE_ID_LEN_BASE32 16 + + if (strlen(query) != REND_SERVICE_ID_LEN_BASE32) + return 0; + + if (strspn(query, BASE32_CHARS) != REND_SERVICE_ID_LEN_BASE32) + return 0; + + return 1; +} + /** Parse the given hostname in address. Returns true if the parsing was * successful and type_out contains the type of the hostname. Else, false is * returned which means it was not recognized and type_out is set to @@ -1675,6 +1692,14 @@ parse_extended_hostname(char *address, hostname_type_t *type_out) if (q != address) { memmove(address, q, strlen(q) + 1 /* also get \0 */); } + /* v2 onion address check. */ + if (strlen(query) == REND_SERVICE_ID_LEN_BASE32) { + *type_out = ONION_V2_HOSTNAME; + if (rend_valid_v2_service_id(query)) { + goto success; + } + goto failed; + }

/* v3 onion address check. */ if (strlen(query) == HS_SERVICE_ADDR_LEN_BASE32) { @@ -1694,7 +1719,8 @@ parse_extended_hostname(char *address, hostname_type_t *type_out) failed: /* otherwise, return to previous state and return 0 */ *s = '.'; - const bool is_onion = (*type_out == ONION_V3_HOSTNAME); + const bool is_onion = (*type_out == ONION_V2_HOSTNAME) || + (*type_out == ONION_V3_HOSTNAME); log_warn(LD_APP, "Invalid %shostname %s; rejecting", is_onion ? "onion " : "", safe_str_client(address)); diff --git a/src/core/or/connection_edge.h b/src/core/or/connection_edge.h index 966a9391d8..72869f348b 100644 --- a/src/core/or/connection_edge.h +++ b/src/core/or/connection_edge.h @@ -80,6 +80,7 @@ typedef enum hostname_type_t { BAD_HOSTNAME, EXIT_HOSTNAME, NORMAL_HOSTNAME, + ONION_V2_HOSTNAME, ONION_V3_HOSTNAME, } hostname_type_t;

diff --git a/src/test/test_hs_common.c b/src/test/test_hs_common.c index 08e0b9b703..7cb6a36f8e 100644 --- a/src/test/test_hs_common.c +++ b/src/test/test_hs_common.c @@ -789,6 +789,8 @@ test_parse_extended_hostname(void *arg) char address1[] = "fooaddress.onion"; char address3[] = "fooaddress.exit"; char address4[] = "www.torproject.org"; + char address5[] = "foo.abcdefghijklmnop.onion"; + char address6[] = "foo.bar.abcdefghijklmnop.onion"; char address7[] = ".abcdefghijklmnop.onion"; char address8[] = "www.25njqamcweflpvkl73j4szahhihoc4xt3ktcgjnpaingr5yhkenl5sid.onion"; @@ -806,6 +808,14 @@ test_parse_extended_hostname(void *arg) tt_assert(parse_extended_hostname(address4, &type)); tt_int_op(type, OP_EQ, NORMAL_HOSTNAME);

+ tt_assert(parse_extended_hostname(address5, &type)); + tt_int_op(type, OP_EQ, ONION_V2_HOSTNAME); + tt_str_op(address5, OP_EQ, "abcdefghijklmnop"); + + tt_assert(parse_extended_hostname(address6, &type)); + tt_int_op(type, OP_EQ, ONION_V2_HOSTNAME); + tt_str_op(address6, OP_EQ, "abcdefghijklmnop"); + tt_assert(!parse_extended_hostname(address7, &type)); tt_int_op(type, OP_EQ, BAD_HOSTNAME);