From 88e9b1e3fcbd3a8edcf1d54528c49f8237906aba Mon Sep 17 00:00:00 2001 From: Ivan Frade Date: Wed, 10 Nov 2021 23:51:28 +0000 Subject: [PATCH 1/2] fetch-pack: redact packfile urls in traces In some setups, packfile uris act as bearer token. It is not recommended to expose them plainly in logs, although in special circunstances (e.g. debug) it makes sense to write them. Redact the packfile URL paths by default, unless the GIT_TRACE_REDACT variable is set to false. This mimics the redacting of the Authorization header in HTTP. Signed-off-by: Ivan Frade Signed-off-by: Junio C Hamano --- Documentation/git.txt | 5 +++-- fetch-pack.c | 5 +++++ pkt-line.c | 40 ++++++++++++++++++++++++++++++++- pkt-line.h | 1 + t/t5702-protocol-v2.sh | 51 ++++++++++++++++++++++++++++++++++++++++++ 5 files changed, 99 insertions(+), 3 deletions(-) diff --git a/Documentation/git.txt b/Documentation/git.txt index d63c65e67d..c91aa2737f 100644 --- a/Documentation/git.txt +++ b/Documentation/git.txt @@ -832,8 +832,9 @@ for full details. `GIT_TRACE_REDACT`:: By default, when tracing is activated, Git redacts the values of - cookies, the "Authorization:" header, and the "Proxy-Authorization:" - header. Set this variable to `0` to prevent this redaction. + cookies, the "Authorization:" header, the "Proxy-Authorization:" + header and packfile URIs. Set this variable to `0` to prevent this + redaction. `GIT_LITERAL_PATHSPECS`:: Setting this variable to `1` will cause Git to treat all diff --git a/fetch-pack.c b/fetch-pack.c index a9604f35a3..8b8c75f33a 100644 --- a/fetch-pack.c +++ b/fetch-pack.c @@ -1653,8 +1653,13 @@ static struct ref *do_fetch_pack_v2(struct fetch_pack_args *args, receive_wanted_refs(&reader, sought, nr_sought); /* get the pack(s) */ + if (git_env_bool("GIT_TRACE_REDACT", 1)) + reader.options |= PACKET_READ_REDACT_URI_PATH; if (process_section_header(&reader, "packfile-uris", 1)) receive_packfile_uris(&reader, &packfile_uris); + /* We don't expect more URIs. Reset to avoid expensive URI check. */ + reader.options &= ~PACKET_READ_REDACT_URI_PATH; + process_section_header(&reader, "packfile", 0); /* diff --git a/pkt-line.c b/pkt-line.c index 2dc8ac274b..8e43c2def4 100644 --- a/pkt-line.c +++ b/pkt-line.c @@ -370,6 +370,32 @@ int packet_length(const char lenbuf_hex[4]) return (val < 0) ? val : (val << 8) | hex2chr(lenbuf_hex + 2); } +static char *find_packfile_uri_path(const char *buffer) +{ + const char *URI_MARK = "://"; + char *path; + int len; + + /* First char is sideband mark */ + buffer += 1; + + len = strspn(buffer, "0123456789abcdefABCDEF"); + /* size of SHA1 and SHA256 hash */ + if (!(len == 40 || len == 64) || buffer[len] != ' ') + return NULL; /* required "SP" not seen */ + + path = strstr(buffer + len + 1, URI_MARK); + if (!path) + return NULL; + + path = strchr(path + strlen(URI_MARK), '/'); + if (!path || !*(path + 1)) + return NULL; + + /* position after '/' */ + return ++path; +} + enum packet_read_status packet_read_with_status(int fd, char **src_buffer, size_t *src_len, char *buffer, unsigned size, int *pktlen, @@ -377,6 +403,7 @@ enum packet_read_status packet_read_with_status(int fd, char **src_buffer, { int len; char linelen[4]; + char *uri_path_start; if (get_packet_data(fd, src_buffer, src_len, linelen, 4, options) < 0) { *pktlen = -1; @@ -427,7 +454,18 @@ enum packet_read_status packet_read_with_status(int fd, char **src_buffer, len--; buffer[len] = 0; - packet_trace(buffer, len, 0); + if (options & PACKET_READ_REDACT_URI_PATH && + (uri_path_start = find_packfile_uri_path(buffer))) { + const char *redacted = ""; + struct strbuf tracebuf = STRBUF_INIT; + strbuf_insert(&tracebuf, 0, buffer, len); + strbuf_splice(&tracebuf, uri_path_start - buffer, + strlen(uri_path_start), redacted, strlen(redacted)); + packet_trace(tracebuf.buf, tracebuf.len, 0); + strbuf_release(&tracebuf); + } else { + packet_trace(buffer, len, 0); + } if ((options & PACKET_READ_DIE_ON_ERR_PACKET) && starts_with(buffer, "ERR ")) diff --git a/pkt-line.h b/pkt-line.h index 467ae01357..6d2a63db23 100644 --- a/pkt-line.h +++ b/pkt-line.h @@ -87,6 +87,7 @@ void packet_fflush(FILE *f); #define PACKET_READ_CHOMP_NEWLINE (1u<<1) #define PACKET_READ_DIE_ON_ERR_PACKET (1u<<2) #define PACKET_READ_GENTLE_ON_READ_ERROR (1u<<3) +#define PACKET_READ_REDACT_URI_PATH (1u<<4) int packet_read(int fd, char *buffer, unsigned size, int options); /* diff --git a/t/t5702-protocol-v2.sh b/t/t5702-protocol-v2.sh index d527cf6c49..78f85b0714 100755 --- a/t/t5702-protocol-v2.sh +++ b/t/t5702-protocol-v2.sh @@ -1107,6 +1107,57 @@ test_expect_success 'packfile-uri with transfer.fsckobjects fails when .gitmodul test_i18ngrep "disallowed submodule name" err ' +test_expect_success 'packfile-uri path redacted in trace' ' + P="$HTTPD_DOCUMENT_ROOT_PATH/http_parent" && + rm -rf "$P" http_child log && + + git init "$P" && + git -C "$P" config "uploadpack.allowsidebandall" "true" && + + echo my-blob >"$P/my-blob" && + git -C "$P" add my-blob && + git -C "$P" commit -m x && + + git -C "$P" hash-object my-blob >objh && + git -C "$P" pack-objects "$HTTPD_DOCUMENT_ROOT_PATH/mypack" packh && + git -C "$P" config --add \ + "uploadpack.blobpackfileuri" \ + "$(cat objh) $(cat packh) $HTTPD_URL/dumb/mypack-$(cat packh).pack" && + + GIT_TRACE_PACKET="$(pwd)/log" \ + git -c protocol.version=2 \ + -c fetch.uriprotocols=http,https \ + clone "$HTTPD_URL/smart/http_parent" http_child && + + grep -F "clone< \\1$(cat packh) $HTTPD_URL/" log +' + +test_expect_success 'packfile-uri path not redacted in trace when GIT_TRACE_REDACT=0' ' + P="$HTTPD_DOCUMENT_ROOT_PATH/http_parent" && + rm -rf "$P" http_child log && + + git init "$P" && + git -C "$P" config "uploadpack.allowsidebandall" "true" && + + echo my-blob >"$P/my-blob" && + git -C "$P" add my-blob && + git -C "$P" commit -m x && + + git -C "$P" hash-object my-blob >objh && + git -C "$P" pack-objects "$HTTPD_DOCUMENT_ROOT_PATH/mypack" packh && + git -C "$P" config --add \ + "uploadpack.blobpackfileuri" \ + "$(cat objh) $(cat packh) $HTTPD_URL/dumb/mypack-$(cat packh).pack" && + + GIT_TRACE_PACKET="$(pwd)/log" \ + GIT_TRACE_REDACT=0 \ + git -c protocol.version=2 \ + -c fetch.uriprotocols=http,https \ + clone "$HTTPD_URL/smart/http_parent" http_child && + + grep -F "clone< \\1$(cat packh) $HTTPD_URL/dumb/mypack-$(cat packh).pack" log +' + test_expect_success 'http:// --negotiate-only' ' SERVER="$HTTPD_DOCUMENT_ROOT_PATH/server" && URI="$HTTPD_URL/smart/server" && From 0ba558ffb138f893f786d42b19689898ef456515 Mon Sep 17 00:00:00 2001 From: Ivan Frade Date: Wed, 10 Nov 2021 23:51:29 +0000 Subject: [PATCH 2/2] http-fetch: redact url on die() message http-fetch prints the URL after failing to fetch it. This can be confusing to users (they cannot really do anything with it), and they can share by accident a sensitive URL (e.g. with credentials) while looking for help. Redact the URL unless the GIT_TRACE_REDACT variable is set to false. This mimics the redaction of other sensitive information in git, like the Authorization header in HTTP. Fix also capitalization of previous die() message (must start in lowercase). Signed-off-by: Ivan Frade Signed-off-by: Junio C Hamano --- http-fetch.c | 14 ++++++++++++-- 1 file changed, 12 insertions(+), 2 deletions(-) diff --git a/http-fetch.c b/http-fetch.c index fa642462a9..c7c7d391ac 100644 --- a/http-fetch.c +++ b/http-fetch.c @@ -4,6 +4,7 @@ #include "http.h" #include "walker.h" #include "strvec.h" +#include "urlmatch.h" static const char http_fetch_usage[] = "git http-fetch " "[-c] [-t] [-a] [-v] [--recover] [-w ref] [--stdin | --packfile=hash | commit-id] url"; @@ -63,8 +64,17 @@ static void fetch_single_packfile(struct object_id *packfile_hash, if (start_active_slot(preq->slot)) { run_active_slot(preq->slot); if (results.curl_result != CURLE_OK) { - die("Unable to get pack file %s\n%s", preq->url, - curl_errorstr); + struct url_info url; + char *nurl = url_normalize(preq->url, &url); + if (!nurl || !git_env_bool("GIT_TRACE_REDACT", 1)) { + die("unable to get pack file '%s'\n%s", preq->url, + curl_errorstr); + } else { + die("failed to get '%.*s' url from '%.*s' " + "(full URL redacted due to GIT_TRACE_REDACT setting)\n%s", + (int)url.scheme_len, url.url, + (int)url.host_len, &url.url[url.host_off], curl_errorstr); + } } } else { die("Unable to start request");