diff --git a/Documentation/git-credential.txt b/Documentation/git-credential.txt index 29d184ab82..3394c03611 100644 --- a/Documentation/git-credential.txt +++ b/Documentation/git-credential.txt @@ -113,7 +113,13 @@ separated by an `=` (equals) sign, followed by a newline. The key may contain any bytes except `=`, newline, or NUL. The value may contain any bytes except newline or NUL. -In both cases, all bytes are treated as-is (i.e., there is no quoting, +Attributes with keys that end with C-style array brackets `[]` can have +multiple values. Each instance of a multi-valued attribute forms an +ordered list of values - the order of the repeated attributes defines +the order of the values. An empty multi-valued attribute (`key[]=\n`) +acts to clear any previous entries and reset the list. + +In all cases, all bytes are treated as-is (i.e., there is no quoting, and one cannot transmit a value with newline or NUL in it). The list of attributes is terminated by a blank line or end-of-file. @@ -166,6 +172,17 @@ empty string. Components which are missing from the URL (e.g., there is no username in the example above) will be left unset. +`wwwauth[]`:: + + When an HTTP response is received by Git that includes one or more + 'WWW-Authenticate' authentication headers, these will be passed by Git + to credential helpers. ++ +Each 'WWW-Authenticate' header value is passed as a multi-valued +attribute 'wwwauth[]', where the order of the attributes is the same as +they appear in the HTTP response. This attribute is 'one-way' from Git +to pass additional information to credential helpers. + Unrecognised attributes are silently discarded. GIT diff --git a/credential.c b/credential.c index f32011343f..ea40a2a410 100644 --- a/credential.c +++ b/credential.c @@ -23,6 +23,7 @@ void credential_clear(struct credential *c) free(c->username); free(c->password); string_list_clear(&c->helpers, 0); + strvec_clear(&c->wwwauth_headers); credential_init(c); } @@ -280,6 +281,8 @@ void credential_write(const struct credential *c, FILE *fp) credential_write_item(fp, "password_expiry_utc", s, 0); free(s); } + for (size_t i = 0; i < c->wwwauth_headers.nr; i++) + credential_write_item(fp, "wwwauth[]", c->wwwauth_headers.v[i], 0); } static int run_credential_helper(struct credential *c, diff --git a/credential.h b/credential.h index 935b28a70f..2b5958cd43 100644 --- a/credential.h +++ b/credential.h @@ -2,6 +2,7 @@ #define CREDENTIAL_H #include "string-list.h" +#include "strvec.h" /** * The credentials API provides an abstracted way of gathering username and @@ -115,6 +116,20 @@ struct credential { */ struct string_list helpers; + /** + * A `strvec` of WWW-Authenticate header values. Each string + * is the value of a WWW-Authenticate header in an HTTP response, + * in the order they were received in the response. + */ + struct strvec wwwauth_headers; + + /** + * Internal use only. Keeps track of if we previously matched against a + * WWW-Authenticate header line in order to re-fold future continuation + * lines into one value. + */ + unsigned header_is_last_match:1; + unsigned approved:1, configured:1, quit:1, @@ -132,6 +147,7 @@ struct credential { #define CREDENTIAL_INIT { \ .helpers = STRING_LIST_INIT_DUP, \ .password_expiry_utc = TIME_MAX, \ + .wwwauth_headers = STRVEC_INIT, \ } /* Initialize a credential structure, setting all fields to empty. */ diff --git a/git-compat-util.h b/git-compat-util.h index f77f986fbf..1e6592624d 100644 --- a/git-compat-util.h +++ b/git-compat-util.h @@ -1288,6 +1288,25 @@ static inline int skip_iprefix(const char *str, const char *prefix, return 0; } +/* + * Like skip_prefix_mem, but compare case-insensitively. Note that the + * comparison is done via tolower(), so it is strictly ASCII (no multi-byte + * characters or locale-specific conversions). + */ +static inline int skip_iprefix_mem(const char *buf, size_t len, + const char *prefix, + const char **out, size_t *outlen) +{ + do { + if (!*prefix) { + *out = buf; + *outlen = len; + return 1; + } + } while (len-- > 0 && tolower(*buf++) == tolower(*prefix++)); + return 0; +} + static inline int strtoul_ui(char const *s, int base, unsigned int *result) { unsigned long ul; diff --git a/http.c b/http.c index 86b0745af9..dbe4d29ef7 100644 --- a/http.c +++ b/http.c @@ -182,6 +182,115 @@ size_t fwrite_buffer(char *ptr, size_t eltsize, size_t nmemb, void *buffer_) return nmemb; } +/* + * A folded header continuation line starts with any number of spaces or + * horizontal tab characters (SP or HTAB) as per RFC 7230 section 3.2. + * It is not a continuation line if the line starts with any other character. + */ +static inline int is_hdr_continuation(const char *ptr, const size_t size) +{ + return size && (*ptr == ' ' || *ptr == '\t'); +} + +static size_t fwrite_wwwauth(char *ptr, size_t eltsize, size_t nmemb, void *p) +{ + size_t size = eltsize * nmemb; + struct strvec *values = &http_auth.wwwauth_headers; + struct strbuf buf = STRBUF_INIT; + const char *val; + size_t val_len; + + /* + * Header lines may not come NULL-terminated from libcurl so we must + * limit all scans to the maximum length of the header line, or leverage + * strbufs for all operations. + * + * In addition, it is possible that header values can be split over + * multiple lines as per RFC 7230. 'Line folding' has been deprecated + * but older servers may still emit them. A continuation header field + * value is identified as starting with a space or horizontal tab. + * + * The formal definition of a header field as given in RFC 7230 is: + * + * header-field = field-name ":" OWS field-value OWS + * + * field-name = token + * field-value = *( field-content / obs-fold ) + * field-content = field-vchar [ 1*( SP / HTAB ) field-vchar ] + * field-vchar = VCHAR / obs-text + * + * obs-fold = CRLF 1*( SP / HTAB ) + * ; obsolete line folding + * ; see Section 3.2.4 + */ + + /* Start of a new WWW-Authenticate header */ + if (skip_iprefix_mem(ptr, size, "www-authenticate:", &val, &val_len)) { + strbuf_add(&buf, val, val_len); + + /* + * Strip the CRLF that should be present at the end of each + * field as well as any trailing or leading whitespace from the + * value. + */ + strbuf_trim(&buf); + + strvec_push(values, buf.buf); + http_auth.header_is_last_match = 1; + goto exit; + } + + /* + * This line could be a continuation of the previously matched header + * field. If this is the case then we should append this value to the + * end of the previously consumed value. + */ + if (http_auth.header_is_last_match && is_hdr_continuation(ptr, size)) { + /* + * Trim the CRLF and any leading or trailing from this line. + */ + strbuf_add(&buf, ptr, size); + strbuf_trim(&buf); + + /* + * At this point we should always have at least one existing + * value, even if it is empty. Do not bother appending the new + * value if this continuation header is itself empty. + */ + if (!values->nr) { + BUG("should have at least one existing header value"); + } else if (buf.len) { + char *prev = xstrdup(values->v[values->nr - 1]); + + /* Join two non-empty values with a single space. */ + const char *const sp = *prev ? " " : ""; + + strvec_pop(values); + strvec_pushf(values, "%s%s%s", prev, sp, buf.buf); + free(prev); + } + + goto exit; + } + + /* Not a continuation of a previously matched auth header line. */ + http_auth.header_is_last_match = 0; + + /* + * If this is a HTTP status line and not a header field, this signals + * a different HTTP response. libcurl writes all the output of all + * response headers of all responses, including redirects. + * We only care about the last HTTP request response's headers so clear + * the existing array. + */ + if (skip_iprefix_mem(ptr, size, "http/", &val, &val_len)) + strvec_clear(values); + +exit: + strbuf_release(&buf); + return size; +} + size_t fwrite_null(char *ptr, size_t eltsize, size_t nmemb, void *strbuf) { return nmemb; @@ -1896,6 +2005,8 @@ static int http_request(const char *url, fwrite_buffer); } + curl_easy_setopt(slot->curl, CURLOPT_HEADERFUNCTION, fwrite_wwwauth); + accept_language = http_get_accept_language_header(); if (accept_language) diff --git a/t/lib-httpd.sh b/t/lib-httpd.sh index 09cf5ed012..3e876536eb 100644 --- a/t/lib-httpd.sh +++ b/t/lib-httpd.sh @@ -142,6 +142,7 @@ prepare_httpd() { install_script error-smart-http.sh install_script error.sh install_script apply-one-time-perl.sh + install_script nph-custom-auth.sh ln -s "$LIB_HTTPD_MODULE_PATH" "$HTTPD_ROOT_PATH/modules" diff --git a/t/lib-httpd/apache.conf b/t/lib-httpd/apache.conf index 31f82fa093..f43a25c1f1 100644 --- a/t/lib-httpd/apache.conf +++ b/t/lib-httpd/apache.conf @@ -141,6 +141,11 @@ Alias /auth/dumb/ www/auth/dumb/ SetEnv GIT_HTTP_EXPORT_ALL SetEnv GIT_PROTOCOL + + SetEnv GIT_EXEC_PATH ${GIT_EXEC_PATH} + SetEnv GIT_HTTP_EXPORT_ALL + CGIPassAuth on + ScriptAlias /smart/incomplete_length/git-upload-pack incomplete-length-upload-pack-v2-http.sh/ ScriptAlias /smart/incomplete_body/git-upload-pack incomplete-body-upload-pack-v2-http.sh/ ScriptAlias /smart/no_report/git-receive-pack error-no-report.sh/ @@ -150,6 +155,7 @@ ScriptAlias /broken_smart/ broken-smart-http.sh/ ScriptAlias /error_smart/ error-smart-http.sh/ ScriptAlias /error/ error.sh/ ScriptAliasMatch /one_time_perl/(.*) apply-one-time-perl.sh/$1 +ScriptAliasMatch /custom_auth/(.*) nph-custom-auth.sh/$1 Options FollowSymlinks diff --git a/t/lib-httpd/nph-custom-auth.sh b/t/lib-httpd/nph-custom-auth.sh new file mode 100644 index 0000000000..f5345e775e --- /dev/null +++ b/t/lib-httpd/nph-custom-auth.sh @@ -0,0 +1,39 @@ +#!/bin/sh + +VALID_CREDS_FILE=custom-auth.valid +CHALLENGE_FILE=custom-auth.challenge + +# +# If $VALID_CREDS_FILE exists in $HTTPD_ROOT_PATH, consider each line as a valid +# credential for the current request. Each line in the file is considered a +# valid HTTP Authorization header value. For example: +# +# Basic YWxpY2U6c2VjcmV0LXBhc3N3ZA== +# +# If $CHALLENGE_FILE exists in $HTTPD_ROOT_PATH, output the contents as headers +# in a 401 response if no valid authentication credentials were included in the +# request. For example: +# +# WWW-Authenticate: Bearer authorize_uri="id.example.com" p=1 q=0 +# WWW-Authenticate: Basic realm="example.com" +# + +if test -n "$HTTP_AUTHORIZATION" && \ + grep -Fqsx "${HTTP_AUTHORIZATION}" "$VALID_CREDS_FILE" +then + # Note that although git-http-backend returns a status line, it + # does so using a CGI 'Status' header. Because this script is an + # No Parsed Headers (NPH) script, we must return a real HTTP + # status line. + # This is only a test script, so we don't bother to check for + # the actual status from git-http-backend and always return 200. + echo 'HTTP/1.1 200 OK' + exec "$GIT_EXEC_PATH"/git-http-backend +fi + +echo 'HTTP/1.1 401 Authorization Required' +if test -f "$CHALLENGE_FILE" +then + cat "$CHALLENGE_FILE" +fi +echo diff --git a/t/t5563-simple-http-auth.sh b/t/t5563-simple-http-auth.sh new file mode 100755 index 0000000000..ccf7e54b07 --- /dev/null +++ b/t/t5563-simple-http-auth.sh @@ -0,0 +1,325 @@ +#!/bin/sh + +test_description='test http auth header and credential helper interop' + +. ./test-lib.sh +. "$TEST_DIRECTORY"/lib-httpd.sh + +start_httpd + +test_expect_success 'setup_credential_helper' ' + mkdir "$TRASH_DIRECTORY/bin" && + PATH=$PATH:"$TRASH_DIRECTORY/bin" && + export PATH && + + CREDENTIAL_HELPER="$TRASH_DIRECTORY/bin/git-credential-test-helper" && + write_script "$CREDENTIAL_HELPER" <<-\EOF + cmd=$1 + teefile=$cmd-query.cred + catfile=$cmd-reply.cred + sed -n -e "/^$/q" -e "p" >>$teefile + if test "$cmd" = "get" + then + cat $catfile + fi + EOF +' + +set_credential_reply () { + cat >"$TRASH_DIRECTORY/$1-reply.cred" +} + +expect_credential_query () { + cat >"$TRASH_DIRECTORY/$1-expect.cred" && + test_cmp "$TRASH_DIRECTORY/$1-expect.cred" \ + "$TRASH_DIRECTORY/$1-query.cred" +} + +per_test_cleanup () { + rm -f *.cred && + rm -f "$HTTPD_ROOT_PATH"/custom-auth.valid \ + "$HTTPD_ROOT_PATH"/custom-auth.challenge +} + +test_expect_success 'setup repository' ' + test_commit foo && + git init --bare "$HTTPD_DOCUMENT_ROOT_PATH/repo.git" && + git push --mirror "$HTTPD_DOCUMENT_ROOT_PATH/repo.git" +' + +test_expect_success 'access using basic auth' ' + test_when_finished "per_test_cleanup" && + + set_credential_reply get <<-EOF && + username=alice + password=secret-passwd + EOF + + # Basic base64(alice:secret-passwd) + cat >"$HTTPD_ROOT_PATH/custom-auth.valid" <<-EOF && + Basic YWxpY2U6c2VjcmV0LXBhc3N3ZA== + EOF + + cat >"$HTTPD_ROOT_PATH/custom-auth.challenge" <<-EOF && + WWW-Authenticate: Basic realm="example.com" + EOF + + test_config_global credential.helper test-helper && + git ls-remote "$HTTPD_URL/custom_auth/repo.git" && + + expect_credential_query get <<-EOF && + protocol=http + host=$HTTPD_DEST + wwwauth[]=Basic realm="example.com" + EOF + + expect_credential_query store <<-EOF + protocol=http + host=$HTTPD_DEST + username=alice + password=secret-passwd + EOF +' + +test_expect_success 'access using basic auth invalid credentials' ' + test_when_finished "per_test_cleanup" && + + set_credential_reply get <<-EOF && + username=baduser + password=wrong-passwd + EOF + + # Basic base64(alice:secret-passwd) + cat >"$HTTPD_ROOT_PATH/custom-auth.valid" <<-EOF && + Basic YWxpY2U6c2VjcmV0LXBhc3N3ZA== + EOF + + cat >"$HTTPD_ROOT_PATH/custom-auth.challenge" <<-EOF && + WWW-Authenticate: Basic realm="example.com" + EOF + + test_config_global credential.helper test-helper && + test_must_fail git ls-remote "$HTTPD_URL/custom_auth/repo.git" && + + expect_credential_query get <<-EOF && + protocol=http + host=$HTTPD_DEST + wwwauth[]=Basic realm="example.com" + EOF + + expect_credential_query erase <<-EOF + protocol=http + host=$HTTPD_DEST + username=baduser + password=wrong-passwd + wwwauth[]=Basic realm="example.com" + EOF +' + +test_expect_success 'access using basic auth with extra challenges' ' + test_when_finished "per_test_cleanup" && + + set_credential_reply get <<-EOF && + username=alice + password=secret-passwd + EOF + + # Basic base64(alice:secret-passwd) + cat >"$HTTPD_ROOT_PATH/custom-auth.valid" <<-EOF && + Basic YWxpY2U6c2VjcmV0LXBhc3N3ZA== + EOF + + cat >"$HTTPD_ROOT_PATH/custom-auth.challenge" <<-EOF && + WWW-Authenticate: FooBar param1="value1" param2="value2" + WWW-Authenticate: Bearer authorize_uri="id.example.com" p=1 q=0 + WWW-Authenticate: Basic realm="example.com" + EOF + + test_config_global credential.helper test-helper && + git ls-remote "$HTTPD_URL/custom_auth/repo.git" && + + expect_credential_query get <<-EOF && + protocol=http + host=$HTTPD_DEST + wwwauth[]=FooBar param1="value1" param2="value2" + wwwauth[]=Bearer authorize_uri="id.example.com" p=1 q=0 + wwwauth[]=Basic realm="example.com" + EOF + + expect_credential_query store <<-EOF + protocol=http + host=$HTTPD_DEST + username=alice + password=secret-passwd + EOF +' + +test_expect_success 'access using basic auth mixed-case wwwauth header name' ' + test_when_finished "per_test_cleanup" && + + set_credential_reply get <<-EOF && + username=alice + password=secret-passwd + EOF + + # Basic base64(alice:secret-passwd) + cat >"$HTTPD_ROOT_PATH/custom-auth.valid" <<-EOF && + Basic YWxpY2U6c2VjcmV0LXBhc3N3ZA== + EOF + + cat >"$HTTPD_ROOT_PATH/custom-auth.challenge" <<-EOF && + www-authenticate: foobar param1="value1" param2="value2" + WWW-AUTHENTICATE: BEARER authorize_uri="id.example.com" p=1 q=0 + WwW-aUtHeNtIcAtE: baSiC realm="example.com" + EOF + + test_config_global credential.helper test-helper && + git ls-remote "$HTTPD_URL/custom_auth/repo.git" && + + expect_credential_query get <<-EOF && + protocol=http + host=$HTTPD_DEST + wwwauth[]=foobar param1="value1" param2="value2" + wwwauth[]=BEARER authorize_uri="id.example.com" p=1 q=0 + wwwauth[]=baSiC realm="example.com" + EOF + + expect_credential_query store <<-EOF + protocol=http + host=$HTTPD_DEST + username=alice + password=secret-passwd + EOF +' + +test_expect_success 'access using basic auth with wwwauth header continuations' ' + test_when_finished "per_test_cleanup" && + + set_credential_reply get <<-EOF && + username=alice + password=secret-passwd + EOF + + # Basic base64(alice:secret-passwd) + cat >"$HTTPD_ROOT_PATH/custom-auth.valid" <<-EOF && + Basic YWxpY2U6c2VjcmV0LXBhc3N3ZA== + EOF + + # Note that leading and trailing whitespace is important to correctly + # simulate a continuation/folded header. + cat >"$HTTPD_ROOT_PATH/custom-auth.challenge" <<-EOF && + WWW-Authenticate: FooBar param1="value1" + param2="value2" + WWW-Authenticate: Bearer authorize_uri="id.example.com" + p=1 + q=0 + WWW-Authenticate: Basic realm="example.com" + EOF + + test_config_global credential.helper test-helper && + git ls-remote "$HTTPD_URL/custom_auth/repo.git" && + + expect_credential_query get <<-EOF && + protocol=http + host=$HTTPD_DEST + wwwauth[]=FooBar param1="value1" param2="value2" + wwwauth[]=Bearer authorize_uri="id.example.com" p=1 q=0 + wwwauth[]=Basic realm="example.com" + EOF + + expect_credential_query store <<-EOF + protocol=http + host=$HTTPD_DEST + username=alice + password=secret-passwd + EOF +' + +test_expect_success 'access using basic auth with wwwauth header empty continuations' ' + test_when_finished "per_test_cleanup" && + + set_credential_reply get <<-EOF && + username=alice + password=secret-passwd + EOF + + # Basic base64(alice:secret-passwd) + cat >"$HTTPD_ROOT_PATH/custom-auth.valid" <<-EOF && + Basic YWxpY2U6c2VjcmV0LXBhc3N3ZA== + EOF + + CHALLENGE="$HTTPD_ROOT_PATH/custom-auth.challenge" && + + # Note that leading and trailing whitespace is important to correctly + # simulate a continuation/folded header. + printf "">$CHALLENGE && + printf "WWW-Authenticate: FooBar param1=\"value1\"\r\n" >$CHALLENGE && + printf " \r\n" >>$CHALLENGE && + printf " param2=\"value2\"\r\n" >>$CHALLENGE && + printf "WWW-Authenticate: Bearer authorize_uri=\"id.example.com\"\r\n" >>$CHALLENGE && + printf " p=1\r\n" >>$CHALLENGE && + printf " \r\n" >>$CHALLENGE && + printf " q=0\r\n" >>$CHALLENGE && + printf "WWW-Authenticate: Basic realm=\"example.com\"\r\n" >>$CHALLENGE && + + test_config_global credential.helper test-helper && + git ls-remote "$HTTPD_URL/custom_auth/repo.git" && + + expect_credential_query get <<-EOF && + protocol=http + host=$HTTPD_DEST + wwwauth[]=FooBar param1="value1" param2="value2" + wwwauth[]=Bearer authorize_uri="id.example.com" p=1 q=0 + wwwauth[]=Basic realm="example.com" + EOF + + expect_credential_query store <<-EOF + protocol=http + host=$HTTPD_DEST + username=alice + password=secret-passwd + EOF +' + +test_expect_success 'access using basic auth with wwwauth header mixed line-endings' ' + test_when_finished "per_test_cleanup" && + + set_credential_reply get <<-EOF && + username=alice + password=secret-passwd + EOF + + # Basic base64(alice:secret-passwd) + cat >"$HTTPD_ROOT_PATH/custom-auth.valid" <<-EOF && + Basic YWxpY2U6c2VjcmV0LXBhc3N3ZA== + EOF + + CHALLENGE="$HTTPD_ROOT_PATH/custom-auth.challenge" && + + # Note that leading and trailing whitespace is important to correctly + # simulate a continuation/folded header. + printf "">$CHALLENGE && + printf "WWW-Authenticate: FooBar param1=\"value1\"\r\n" >$CHALLENGE && + printf " \r\n" >>$CHALLENGE && + printf "\tparam2=\"value2\"\r\n" >>$CHALLENGE && + printf "WWW-Authenticate: Basic realm=\"example.com\"" >>$CHALLENGE && + + test_config_global credential.helper test-helper && + git ls-remote "$HTTPD_URL/custom_auth/repo.git" && + + expect_credential_query get <<-EOF && + protocol=http + host=$HTTPD_DEST + wwwauth[]=FooBar param1="value1" param2="value2" + wwwauth[]=Basic realm="example.com" + EOF + + expect_credential_query store <<-EOF + protocol=http + host=$HTTPD_DEST + username=alice + password=secret-passwd + EOF +' + +test_done