packaging: Add contrib installation
[platform/upstream/git.git] / http.c
diff --git a/http.c b/http.c
index 69da445..8b23a54 100644 (file)
--- a/http.c
+++ b/http.c
@@ -1,5 +1,6 @@
 #include "git-compat-util.h"
 #include "http.h"
+#include "config.h"
 #include "pack.h"
 #include "sideband.h"
 #include "run-command.h"
 #include "pkt-line.h"
 #include "gettext.h"
 #include "transport.h"
-
+#include "packfile.h"
+#include "protocol.h"
+#include "string-list.h"
+#include "object-store.h"
+
+static struct trace_key trace_curl = TRACE_KEY_INIT(CURL);
+static int trace_curl_data = 1;
+static int trace_curl_redact = 1;
 #if LIBCURL_VERSION_NUM >= 0x070a08
 long int git_curl_ipresolve = CURL_IPRESOLVE_WHATEVER;
 #else
@@ -18,7 +26,7 @@ long int git_curl_ipresolve;
 #endif
 int active_requests;
 int http_is_verbose;
-size_t http_post_buffer = 16 * LARGE_PACKET_MAX;
+ssize_t http_post_buffer = 16 * LARGE_PACKET_MAX;
 
 #if LIBCURL_VERSION_NUM >= 0x070a06
 #define LIBCURL_CAN_HANDLE_AUTH_ANY
@@ -40,6 +48,7 @@ char curl_errorstr[CURL_ERROR_SIZE];
 
 static int curl_ssl_verify = -1;
 static int curl_ssl_try;
+static const char *curl_http_version = NULL;
 static const char *ssl_cert;
 static const char *ssl_cipherlist;
 static const char *ssl_version;
@@ -55,6 +64,9 @@ static struct {
        { "tlsv1.1", CURL_SSLVERSION_TLSv1_1 },
        { "tlsv1.2", CURL_SSLVERSION_TLSv1_2 },
 #endif
+#if LIBCURL_VERSION_NUM >= 0x073400
+       { "tlsv1.3", CURL_SSLVERSION_TLSv1_3 },
+#endif
 };
 #if LIBCURL_VERSION_NUM >= 0x070903
 static const char *ssl_key;
@@ -62,6 +74,9 @@ static const char *ssl_key;
 #if LIBCURL_VERSION_NUM >= 0x070908
 static const char *ssl_capath;
 #endif
+#if LIBCURL_VERSION_NUM >= 0x071304
+static const char *curl_no_proxy;
+#endif
 #if LIBCURL_VERSION_NUM >= 0x072c00
 static const char *ssl_pinnedkey;
 #endif
@@ -70,8 +85,14 @@ static long curl_low_speed_limit = -1;
 static long curl_low_speed_time = -1;
 static int curl_ftp_no_epsv;
 static const char *curl_http_proxy;
-static const char *curl_no_proxy;
 static const char *http_proxy_authmethod;
+
+static const char *http_proxy_ssl_cert;
+static const char *http_proxy_ssl_key;
+static const char *http_proxy_ssl_ca_info;
+static struct credential proxy_cert_auth = CREDENTIAL_INIT;
+static int proxy_ssl_cert_password_required;
+
 static struct {
        const char *name;
        long curlauth_param;
@@ -89,6 +110,18 @@ static struct {
         * here, too
         */
 };
+#ifdef CURLGSSAPI_DELEGATION_FLAG
+static const char *curl_deleg;
+static struct {
+       const char *name;
+       long curl_deleg_param;
+} curl_deleg_levels[] = {
+       { "none", CURLGSSAPI_DELEGATION_NONE },
+       { "policy", CURLGSSAPI_DELEGATION_POLICY_FLAG },
+       { "always", CURLGSSAPI_DELEGATION_FLAG },
+};
+#endif
+
 static struct credential proxy_auth = CREDENTIAL_INIT;
 static const char *curl_proxyuserpwd;
 static const char *curl_cookie_file;
@@ -96,7 +129,9 @@ static int curl_save_cookies;
 struct credential http_auth = CREDENTIAL_INIT;
 static int http_proactive_auth;
 static const char *user_agent;
-static int curl_empty_auth;
+static int curl_empty_auth = -1;
+
+enum http_follow_config http_follow_config = HTTP_FOLLOW_INITIAL;
 
 #if LIBCURL_VERSION_NUM >= 0x071700
 /* Use CURLOPT_KEYPASSWD as is */
@@ -110,15 +145,34 @@ static struct credential cert_auth = CREDENTIAL_INIT;
 static int ssl_cert_password_required;
 #ifdef LIBCURL_CAN_HANDLE_AUTH_ANY
 static unsigned long http_auth_methods = CURLAUTH_ANY;
+static int http_auth_methods_restricted;
+/* Modes for which empty_auth cannot actually help us. */
+static unsigned long empty_auth_useless =
+       CURLAUTH_BASIC
+#ifdef CURLAUTH_DIGEST_IE
+       | CURLAUTH_DIGEST_IE
+#endif
+       | CURLAUTH_DIGEST;
 #endif
 
 static struct curl_slist *pragma_header;
 static struct curl_slist *no_pragma_header;
+static struct string_list extra_http_headers = STRING_LIST_INIT_DUP;
 
 static struct active_request_slot *active_queue_head;
 
 static char *cached_accept_language;
 
+static char *http_ssl_backend;
+
+static int http_schannel_check_revoke = 1;
+/*
+ * With the backend being set to `schannel`, setting sslCAinfo would override
+ * the Certificate Store in cURL v7.60.0 and later, which is not what we want
+ * by default.
+ */
+static int http_schannel_use_ssl_cainfo;
+
 size_t fread_buffer(char *ptr, size_t eltsize, size_t nmemb, void *buffer_)
 {
        size_t size = eltsize * nmemb;
@@ -129,7 +183,7 @@ size_t fread_buffer(char *ptr, size_t eltsize, size_t nmemb, void *buffer_)
        memcpy(ptr, buffer->buf.buf + buffer->posn, size);
        buffer->posn += size;
 
-       return size;
+       return size / eltsize;
 }
 
 #ifndef NO_CURL_IOCTL
@@ -157,12 +211,12 @@ size_t fwrite_buffer(char *ptr, size_t eltsize, size_t nmemb, void *buffer_)
        struct strbuf *buffer = buffer_;
 
        strbuf_add(buffer, ptr, size);
-       return size;
+       return nmemb;
 }
 
 size_t fwrite_null(char *ptr, size_t eltsize, size_t nmemb, void *strbuf)
 {
-       return eltsize * nmemb;
+       return nmemb;
 }
 
 static void closedown_active_slot(struct active_request_slot *slot)
@@ -199,6 +253,13 @@ static void finish_active_slot(struct active_request_slot *slot)
                slot->callback_func(slot->callback_data);
 }
 
+static void xmulti_remove_handle(struct active_request_slot *slot)
+{
+#ifdef USE_CURL_MULTI
+       curl_multi_remove_handle(curlm, slot->curl);
+#endif
+}
+
 #ifdef USE_CURL_MULTI
 static void process_curl_messages(void)
 {
@@ -214,7 +275,7 @@ static void process_curl_messages(void)
                               slot->curl != curl_message->easy_handle)
                                slot = slot->next;
                        if (slot != NULL) {
-                               curl_multi_remove_handle(curlm, slot->curl);
+                               xmulti_remove_handle(slot);
                                slot->curl_result = curl_result;
                                finish_active_slot(slot);
                        } else {
@@ -231,6 +292,9 @@ static void process_curl_messages(void)
 
 static int http_options(const char *var, const char *value, void *cb)
 {
+       if (!strcmp("http.version", var)) {
+               return git_config_string(&curl_http_version, var, value);
+       }
        if (!strcmp("http.sslverify", var)) {
                curl_ssl_verify = git_config_bool(var, value);
                return 0;
@@ -240,10 +304,10 @@ static int http_options(const char *var, const char *value, void *cb)
        if (!strcmp("http.sslversion", var))
                return git_config_string(&ssl_version, var, value);
        if (!strcmp("http.sslcert", var))
-               return git_config_string(&ssl_cert, var, value);
+               return git_config_pathname(&ssl_cert, var, value);
 #if LIBCURL_VERSION_NUM >= 0x070903
        if (!strcmp("http.sslkey", var))
-               return git_config_string(&ssl_key, var, value);
+               return git_config_pathname(&ssl_key, var, value);
 #endif
 #if LIBCURL_VERSION_NUM >= 0x070908
        if (!strcmp("http.sslcapath", var))
@@ -259,6 +323,22 @@ static int http_options(const char *var, const char *value, void *cb)
                curl_ssl_try = git_config_bool(var, value);
                return 0;
        }
+       if (!strcmp("http.sslbackend", var)) {
+               free(http_ssl_backend);
+               http_ssl_backend = xstrdup_or_null(value);
+               return 0;
+       }
+
+       if (!strcmp("http.schannelcheckrevoke", var)) {
+               http_schannel_check_revoke = git_config_bool(var, value);
+               return 0;
+       }
+
+       if (!strcmp("http.schannelusesslcainfo", var)) {
+               http_schannel_use_ssl_cainfo = git_config_bool(var, value);
+               return 0;
+       }
+
        if (!strcmp("http.minsessions", var)) {
                min_curl_sessions = git_config_int(var, value);
 #ifndef USE_CURL_MULTI
@@ -292,15 +372,31 @@ static int http_options(const char *var, const char *value, void *cb)
        if (!strcmp("http.proxyauthmethod", var))
                return git_config_string(&http_proxy_authmethod, var, value);
 
+       if (!strcmp("http.proxysslcert", var))
+               return git_config_string(&http_proxy_ssl_cert, var, value);
+
+       if (!strcmp("http.proxysslkey", var))
+               return git_config_string(&http_proxy_ssl_key, var, value);
+
+       if (!strcmp("http.proxysslcainfo", var))
+               return git_config_string(&http_proxy_ssl_ca_info, var, value);
+
+       if (!strcmp("http.proxysslcertpasswordprotected", var)) {
+               proxy_ssl_cert_password_required = git_config_bool(var, value);
+               return 0;
+       }
+
        if (!strcmp("http.cookiefile", var))
-               return git_config_string(&curl_cookie_file, var, value);
+               return git_config_pathname(&curl_cookie_file, var, value);
        if (!strcmp("http.savecookies", var)) {
                curl_save_cookies = git_config_bool(var, value);
                return 0;
        }
 
        if (!strcmp("http.postbuffer", var)) {
-               http_post_buffer = git_config_int(var, value);
+               http_post_buffer = git_config_ssize_t(var, value);
+               if (http_post_buffer < 0)
+                       warning(_("negative value for http.postbuffer; defaulting to %d"), LARGE_PACKET_MAX);
                if (http_post_buffer < LARGE_PACKET_MAX)
                        http_post_buffer = LARGE_PACKET_MAX;
                return 0;
@@ -310,10 +406,22 @@ static int http_options(const char *var, const char *value, void *cb)
                return git_config_string(&user_agent, var, value);
 
        if (!strcmp("http.emptyauth", var)) {
-               curl_empty_auth = git_config_bool(var, value);
+               if (value && !strcmp("auto", value))
+                       curl_empty_auth = -1;
+               else
+                       curl_empty_auth = git_config_bool(var, value);
                return 0;
        }
 
+       if (!strcmp("http.delegation", var)) {
+#ifdef CURLGSSAPI_DELEGATION_FLAG
+               return git_config_string(&curl_deleg, var, value);
+#else
+               warning(_("Delegation control is not supported with cURL < 7.22.0"));
+               return 0;
+#endif
+       }
+
        if (!strcmp("http.pinnedpubkey", var)) {
 #if LIBCURL_VERSION_NUM >= 0x072c00
                return git_config_pathname(&ssl_pinnedkey, var, value);
@@ -323,14 +431,62 @@ static int http_options(const char *var, const char *value, void *cb)
 #endif
        }
 
+       if (!strcmp("http.extraheader", var)) {
+               if (!value) {
+                       return config_error_nonbool(var);
+               } else if (!*value) {
+                       string_list_clear(&extra_http_headers, 0);
+               } else {
+                       string_list_append(&extra_http_headers, value);
+               }
+               return 0;
+       }
+
+       if (!strcmp("http.followredirects", var)) {
+               if (value && !strcmp(value, "initial"))
+                       http_follow_config = HTTP_FOLLOW_INITIAL;
+               else if (git_config_bool(var, value))
+                       http_follow_config = HTTP_FOLLOW_ALWAYS;
+               else
+                       http_follow_config = HTTP_FOLLOW_NONE;
+               return 0;
+       }
+
        /* Fall back on the default ones */
        return git_default_config(var, value, cb);
 }
 
+static int curl_empty_auth_enabled(void)
+{
+       if (curl_empty_auth >= 0)
+               return curl_empty_auth;
+
+#ifndef LIBCURL_CAN_HANDLE_AUTH_ANY
+       /*
+        * Our libcurl is too old to do AUTH_ANY in the first place;
+        * just default to turning the feature off.
+        */
+#else
+       /*
+        * In the automatic case, kick in the empty-auth
+        * hack as long as we would potentially try some
+        * method more exotic than "Basic" or "Digest".
+        *
+        * But only do this when this is our second or
+        * subsequent request, as by then we know what
+        * methods are available.
+        */
+       if (http_auth_methods_restricted &&
+           (http_auth_methods & ~empty_auth_useless))
+               return 1;
+#endif
+       return 0;
+}
+
 static void init_curl_http_auth(CURL *result)
 {
-       if (!http_auth.username) {
-               if (curl_empty_auth)
+       if (!http_auth.username || !*http_auth.username) {
+               if (curl_empty_auth_enabled())
                        curl_easy_setopt(result, CURLOPT_USERPWD, ":");
                return;
        }
@@ -376,9 +532,11 @@ static void set_proxyauth_name_password(CURL *result)
 #else
                struct strbuf s = STRBUF_INIT;
 
-               strbuf_addstr_urlencode(&s, proxy_auth.username, 1);
+               strbuf_addstr_urlencode(&s, proxy_auth.username,
+                                       is_rfc3986_unreserved);
                strbuf_addch(&s, ':');
-               strbuf_addstr_urlencode(&s, proxy_auth.password, 1);
+               strbuf_addstr_urlencode(&s, proxy_auth.password,
+                                       is_rfc3986_unreserved);
                curl_proxyuserpwd = strbuf_detach(&s, NULL);
                curl_easy_setopt(result, CURLOPT_PROXYUSERPWD, curl_proxyuserpwd);
 #endif
@@ -421,6 +579,7 @@ static int has_cert_password(void)
                return 0;
        if (!cert_auth.password) {
                cert_auth.protocol = xstrdup("cert");
+               cert_auth.host = xstrdup("");
                cert_auth.username = xstrdup("");
                cert_auth.path = xstrdup(ssl_cert);
                credential_fill(&cert_auth);
@@ -428,6 +587,22 @@ static int has_cert_password(void)
        return 1;
 }
 
+#if LIBCURL_VERSION_NUM >= 0x073400
+static int has_proxy_cert_password(void)
+{
+       if (http_proxy_ssl_cert == NULL || proxy_ssl_cert_password_required != 1)
+               return 0;
+       if (!proxy_cert_auth.password) {
+               proxy_cert_auth.protocol = xstrdup("cert");
+               proxy_cert_auth.host = xstrdup("");
+               proxy_cert_auth.username = xstrdup("");
+               proxy_cert_auth.path = xstrdup(http_proxy_ssl_cert);
+               credential_fill(&proxy_cert_auth);
+       }
+       return 1;
+}
+#endif
+
 #if LIBCURL_VERSION_NUM >= 0x071900
 static void set_curl_keepalive(CURL *c)
 {
@@ -446,8 +621,7 @@ static int sockopt_callback(void *client, curl_socket_t fd, curlsocktype type)
 
        rc = setsockopt(fd, SOL_SOCKET, SO_KEEPALIVE, (void *)&ka, len);
        if (rc < 0)
-               warning("unable to set SO_KEEPALIVE on socket %s",
-                       strerror(errno));
+               warning_errno("unable to set SO_KEEPALIVE on socket");
 
        return 0; /* CURL_SOCKOPT_OK only exists since curl 7.21.5 */
 }
@@ -464,10 +638,223 @@ static void set_curl_keepalive(CURL *c)
 }
 #endif
 
+static void redact_sensitive_header(struct strbuf *header)
+{
+       const char *sensitive_header;
+
+       if (trace_curl_redact &&
+           (skip_prefix(header->buf, "Authorization:", &sensitive_header) ||
+            skip_prefix(header->buf, "Proxy-Authorization:", &sensitive_header))) {
+               /* The first token is the type, which is OK to log */
+               while (isspace(*sensitive_header))
+                       sensitive_header++;
+               while (*sensitive_header && !isspace(*sensitive_header))
+                       sensitive_header++;
+               /* Everything else is opaque and possibly sensitive */
+               strbuf_setlen(header,  sensitive_header - header->buf);
+               strbuf_addstr(header, " <redacted>");
+       } else if (trace_curl_redact &&
+                  skip_prefix(header->buf, "Cookie:", &sensitive_header)) {
+               struct strbuf redacted_header = STRBUF_INIT;
+               const char *cookie;
+
+               while (isspace(*sensitive_header))
+                       sensitive_header++;
+
+               cookie = sensitive_header;
+
+               while (cookie) {
+                       char *equals;
+                       char *semicolon = strstr(cookie, "; ");
+                       if (semicolon)
+                               *semicolon = 0;
+                       equals = strchrnul(cookie, '=');
+                       if (!equals) {
+                               /* invalid cookie, just append and continue */
+                               strbuf_addstr(&redacted_header, cookie);
+                               continue;
+                       }
+                       strbuf_add(&redacted_header, cookie, equals - cookie);
+                       strbuf_addstr(&redacted_header, "=<redacted>");
+                       if (semicolon) {
+                               /*
+                                * There are more cookies. (Or, for some
+                                * reason, the input string ends in "; ".)
+                                */
+                               strbuf_addstr(&redacted_header, "; ");
+                               cookie = semicolon + strlen("; ");
+                       } else {
+                               cookie = NULL;
+                       }
+               }
+
+               strbuf_setlen(header, sensitive_header - header->buf);
+               strbuf_addbuf(header, &redacted_header);
+       }
+}
+
+static void curl_dump_header(const char *text, unsigned char *ptr, size_t size, int hide_sensitive_header)
+{
+       struct strbuf out = STRBUF_INIT;
+       struct strbuf **headers, **header;
+
+       strbuf_addf(&out, "%s, %10.10ld bytes (0x%8.8lx)\n",
+               text, (long)size, (long)size);
+       trace_strbuf(&trace_curl, &out);
+       strbuf_reset(&out);
+       strbuf_add(&out, ptr, size);
+       headers = strbuf_split_max(&out, '\n', 0);
+
+       for (header = headers; *header; header++) {
+               if (hide_sensitive_header)
+                       redact_sensitive_header(*header);
+               strbuf_insertstr((*header), 0, text);
+               strbuf_insertstr((*header), strlen(text), ": ");
+               strbuf_rtrim((*header));
+               strbuf_addch((*header), '\n');
+               trace_strbuf(&trace_curl, (*header));
+       }
+       strbuf_list_free(headers);
+       strbuf_release(&out);
+}
+
+static void curl_dump_data(const char *text, unsigned char *ptr, size_t size)
+{
+       size_t i;
+       struct strbuf out = STRBUF_INIT;
+       unsigned int width = 60;
+
+       strbuf_addf(&out, "%s, %10.10ld bytes (0x%8.8lx)\n",
+               text, (long)size, (long)size);
+       trace_strbuf(&trace_curl, &out);
+
+       for (i = 0; i < size; i += width) {
+               size_t w;
+
+               strbuf_reset(&out);
+               strbuf_addf(&out, "%s: ", text);
+               for (w = 0; (w < width) && (i + w < size); w++) {
+                       unsigned char ch = ptr[i + w];
+
+                       strbuf_addch(&out,
+                                      (ch >= 0x20) && (ch < 0x80)
+                                      ? ch : '.');
+               }
+               strbuf_addch(&out, '\n');
+               trace_strbuf(&trace_curl, &out);
+       }
+       strbuf_release(&out);
+}
+
+static int curl_trace(CURL *handle, curl_infotype type, char *data, size_t size, void *userp)
+{
+       const char *text;
+       enum { NO_FILTER = 0, DO_FILTER = 1 };
+
+       switch (type) {
+       case CURLINFO_TEXT:
+               trace_printf_key(&trace_curl, "== Info: %s", data);
+               break;
+       case CURLINFO_HEADER_OUT:
+               text = "=> Send header";
+               curl_dump_header(text, (unsigned char *)data, size, DO_FILTER);
+               break;
+       case CURLINFO_DATA_OUT:
+               if (trace_curl_data) {
+                       text = "=> Send data";
+                       curl_dump_data(text, (unsigned char *)data, size);
+               }
+               break;
+       case CURLINFO_SSL_DATA_OUT:
+               if (trace_curl_data) {
+                       text = "=> Send SSL data";
+                       curl_dump_data(text, (unsigned char *)data, size);
+               }
+               break;
+       case CURLINFO_HEADER_IN:
+               text = "<= Recv header";
+               curl_dump_header(text, (unsigned char *)data, size, NO_FILTER);
+               break;
+       case CURLINFO_DATA_IN:
+               if (trace_curl_data) {
+                       text = "<= Recv data";
+                       curl_dump_data(text, (unsigned char *)data, size);
+               }
+               break;
+       case CURLINFO_SSL_DATA_IN:
+               if (trace_curl_data) {
+                       text = "<= Recv SSL data";
+                       curl_dump_data(text, (unsigned char *)data, size);
+               }
+               break;
+
+       default:                /* we ignore unknown types by default */
+               return 0;
+       }
+       return 0;
+}
+
+void http_trace_curl_no_data(void)
+{
+       trace_override_envvar(&trace_curl, "1");
+       trace_curl_data = 0;
+}
+
+void setup_curl_trace(CURL *handle)
+{
+       if (!trace_want(&trace_curl))
+               return;
+       curl_easy_setopt(handle, CURLOPT_VERBOSE, 1L);
+       curl_easy_setopt(handle, CURLOPT_DEBUGFUNCTION, curl_trace);
+       curl_easy_setopt(handle, CURLOPT_DEBUGDATA, NULL);
+}
+
+#ifdef CURLPROTO_HTTP
+static long get_curl_allowed_protocols(int from_user)
+{
+       long allowed_protocols = 0;
+
+       if (is_transport_allowed("http", from_user))
+               allowed_protocols |= CURLPROTO_HTTP;
+       if (is_transport_allowed("https", from_user))
+               allowed_protocols |= CURLPROTO_HTTPS;
+       if (is_transport_allowed("ftp", from_user))
+               allowed_protocols |= CURLPROTO_FTP;
+       if (is_transport_allowed("ftps", from_user))
+               allowed_protocols |= CURLPROTO_FTPS;
+
+       return allowed_protocols;
+}
+#endif
+
+#if LIBCURL_VERSION_NUM >=0x072f00
+static int get_curl_http_version_opt(const char *version_string, long *opt)
+{
+       int i;
+       static struct {
+               const char *name;
+               long opt_token;
+       } choice[] = {
+               { "HTTP/1.1", CURL_HTTP_VERSION_1_1 },
+               { "HTTP/2", CURL_HTTP_VERSION_2 }
+       };
+
+       for (i = 0; i < ARRAY_SIZE(choice); i++) {
+               if (!strcmp(version_string, choice[i].name)) {
+                       *opt = choice[i].opt_token;
+                       return 0;
+               }
+       }
+
+       warning("unknown value given to http.version: '%s'", version_string);
+       return -1; /* not found */
+}
+
+#endif
+
 static CURL *get_curl_handle(void)
 {
        CURL *result = curl_easy_init();
-       long allowed_protocols = 0;
 
        if (!result)
                die("curl_easy_init failed");
@@ -482,6 +869,16 @@ static CURL *get_curl_handle(void)
                curl_easy_setopt(result, CURLOPT_SSL_VERIFYHOST, 2);
        }
 
+#if LIBCURL_VERSION_NUM >= 0x072f00 // 7.47.0
+    if (curl_http_version) {
+               long opt;
+               if (!get_curl_http_version_opt(curl_http_version, &opt)) {
+                       /* Set request use http version */
+                       curl_easy_setopt(result, CURLOPT_HTTP_VERSION, opt);
+               }
+    }
+#endif
+
 #if LIBCURL_VERSION_NUM >= 0x070907
        curl_easy_setopt(result, CURLOPT_NETRC, CURL_NETRC_OPTIONAL);
 #endif
@@ -489,6 +886,31 @@ static CURL *get_curl_handle(void)
        curl_easy_setopt(result, CURLOPT_HTTPAUTH, CURLAUTH_ANY);
 #endif
 
+#ifdef CURLGSSAPI_DELEGATION_FLAG
+       if (curl_deleg) {
+               int i;
+               for (i = 0; i < ARRAY_SIZE(curl_deleg_levels); i++) {
+                       if (!strcmp(curl_deleg, curl_deleg_levels[i].name)) {
+                               curl_easy_setopt(result, CURLOPT_GSSAPI_DELEGATION,
+                                               curl_deleg_levels[i].curl_deleg_param);
+                               break;
+                       }
+               }
+               if (i == ARRAY_SIZE(curl_deleg_levels))
+                       warning("Unknown delegation method '%s': using default",
+                               curl_deleg);
+       }
+#endif
+
+       if (http_ssl_backend && !strcmp("schannel", http_ssl_backend) &&
+           !http_schannel_check_revoke) {
+#if LIBCURL_VERSION_NUM >= 0x072c00
+               curl_easy_setopt(result, CURLOPT_SSL_OPTIONS, CURLSSLOPT_NO_REVOKE);
+#else
+               warning(_("CURLSSLOPT_NO_REVOKE not supported with cURL < 7.44.0"));
+#endif
+       }
+
        if (http_proactive_auth)
                init_curl_http_auth(result);
 
@@ -530,8 +952,20 @@ static CURL *get_curl_handle(void)
        if (ssl_pinnedkey != NULL)
                curl_easy_setopt(result, CURLOPT_PINNEDPUBLICKEY, ssl_pinnedkey);
 #endif
-       if (ssl_cainfo != NULL)
-               curl_easy_setopt(result, CURLOPT_CAINFO, ssl_cainfo);
+       if (http_ssl_backend && !strcmp("schannel", http_ssl_backend) &&
+           !http_schannel_use_ssl_cainfo) {
+               curl_easy_setopt(result, CURLOPT_CAINFO, NULL);
+#if LIBCURL_VERSION_NUM >= 0x073400
+               curl_easy_setopt(result, CURLOPT_PROXY_CAINFO, NULL);
+#endif
+       } else if (ssl_cainfo != NULL || http_proxy_ssl_ca_info != NULL) {
+               if (ssl_cainfo != NULL)
+                       curl_easy_setopt(result, CURLOPT_CAINFO, ssl_cainfo);
+#if LIBCURL_VERSION_NUM >= 0x073400
+               if (http_proxy_ssl_ca_info != NULL)
+                       curl_easy_setopt(result, CURLOPT_PROXY_CAINFO, http_proxy_ssl_ca_info);
+#endif
+       }
 
        if (curl_low_speed_limit > 0 && curl_low_speed_time > 0) {
                curl_easy_setopt(result, CURLOPT_LOW_SPEED_LIMIT,
@@ -540,31 +974,27 @@ static CURL *get_curl_handle(void)
                                 curl_low_speed_time);
        }
 
-       curl_easy_setopt(result, CURLOPT_FOLLOWLOCATION, 1);
        curl_easy_setopt(result, CURLOPT_MAXREDIRS, 20);
 #if LIBCURL_VERSION_NUM >= 0x071301
        curl_easy_setopt(result, CURLOPT_POSTREDIR, CURL_REDIR_POST_ALL);
 #elif LIBCURL_VERSION_NUM >= 0x071101
        curl_easy_setopt(result, CURLOPT_POST301, 1);
 #endif
-#if LIBCURL_VERSION_NUM >= 0x071304
-       if (is_transport_allowed("http"))
-               allowed_protocols |= CURLPROTO_HTTP;
-       if (is_transport_allowed("https"))
-               allowed_protocols |= CURLPROTO_HTTPS;
-       if (is_transport_allowed("ftp"))
-               allowed_protocols |= CURLPROTO_FTP;
-       if (is_transport_allowed("ftps"))
-               allowed_protocols |= CURLPROTO_FTPS;
-       curl_easy_setopt(result, CURLOPT_REDIR_PROTOCOLS, allowed_protocols);
+#ifdef CURLPROTO_HTTP
+       curl_easy_setopt(result, CURLOPT_REDIR_PROTOCOLS,
+                        get_curl_allowed_protocols(0));
+       curl_easy_setopt(result, CURLOPT_PROTOCOLS,
+                        get_curl_allowed_protocols(-1));
 #else
-       if (transport_restrict_protocols())
-               warning("protocol restrictions not applied to curl redirects because\n"
-                       "your curl version is too old (>= 7.19.4)");
+       warning(_("Protocol restrictions not supported with cURL < 7.19.4"));
 #endif
-
        if (getenv("GIT_CURL_VERBOSE"))
-               curl_easy_setopt(result, CURLOPT_VERBOSE, 1);
+               http_trace_curl_no_data();
+       setup_curl_trace(result);
+       if (getenv("GIT_TRACE_CURL_NO_DATA"))
+               trace_curl_data = 0;
+       if (!git_env_bool("GIT_TRACE_REDACT", 1))
+               trace_curl_redact = 0;
 
        curl_easy_setopt(result, CURLOPT_USERAGENT,
                user_agent ? user_agent : git_user_agent());
@@ -590,7 +1020,7 @@ static CURL *get_curl_handle(void)
         * precedence here, as in CURL.
         */
        if (!curl_http_proxy) {
-               if (!strcmp(http_auth.protocol, "https")) {
+               if (http_auth.protocol && !strcmp(http_auth.protocol, "https")) {
                        var_override(&curl_http_proxy, getenv("HTTPS_PROXY"));
                        var_override(&curl_http_proxy, getenv("https_proxy"));
                } else {
@@ -602,10 +1032,19 @@ static CURL *get_curl_handle(void)
                }
        }
 
-       if (curl_http_proxy) {
-               curl_easy_setopt(result, CURLOPT_PROXY, curl_http_proxy);
+       if (curl_http_proxy && curl_http_proxy[0] == '\0') {
+               /*
+                * Handle case with the empty http.proxy value here to keep
+                * common code clean.
+                * NB: empty option disables proxying at all.
+                */
+               curl_easy_setopt(result, CURLOPT_PROXY, "");
+       } else if (curl_http_proxy) {
 #if LIBCURL_VERSION_NUM >= 0x071800
-               if (starts_with(curl_http_proxy, "socks5"))
+               if (starts_with(curl_http_proxy, "socks5h"))
+                       curl_easy_setopt(result,
+                               CURLOPT_PROXYTYPE, CURLPROXY_SOCKS5_HOSTNAME);
+               else if (starts_with(curl_http_proxy, "socks5"))
                        curl_easy_setopt(result,
                                CURLOPT_PROXYTYPE, CURLPROXY_SOCKS5);
                else if (starts_with(curl_http_proxy, "socks4a"))
@@ -615,6 +1054,20 @@ static CURL *get_curl_handle(void)
                        curl_easy_setopt(result,
                                CURLOPT_PROXYTYPE, CURLPROXY_SOCKS4);
 #endif
+#if LIBCURL_VERSION_NUM >= 0x073400
+               else if (starts_with(curl_http_proxy, "https")) {
+                       curl_easy_setopt(result, CURLOPT_PROXYTYPE, CURLPROXY_HTTPS);
+
+                       if (http_proxy_ssl_cert)
+                               curl_easy_setopt(result, CURLOPT_PROXY_SSLCERT, http_proxy_ssl_cert);
+
+                       if (http_proxy_ssl_key)
+                               curl_easy_setopt(result, CURLOPT_PROXY_SSLKEY, http_proxy_ssl_key);
+
+                       if (has_proxy_cert_password())
+                               curl_easy_setopt(result, CURLOPT_PROXY_KEYPASSWD, proxy_cert_auth.password);
+               }
+#endif
                if (strstr(curl_http_proxy, "://"))
                        credential_from_url(&proxy_auth, curl_http_proxy);
                else {
@@ -624,6 +1077,9 @@ static CURL *get_curl_handle(void)
                        strbuf_release(&url);
                }
 
+               if (!proxy_auth.host)
+                       die("Invalid proxy URL '%s'", curl_http_proxy);
+
                curl_easy_setopt(result, CURLOPT_PROXY, proxy_auth.host);
 #if LIBCURL_VERSION_NUM >= 0x071304
                var_override(&curl_no_proxy, getenv("NO_PROXY"));
@@ -663,6 +1119,34 @@ void http_init(struct remote *remote, const char *url, int proactive_auth)
 
        git_config(urlmatch_config_entry, &config);
        free(normalized_url);
+       string_list_clear(&config.vars, 1);
+
+#if LIBCURL_VERSION_NUM >= 0x073800
+       if (http_ssl_backend) {
+               const curl_ssl_backend **backends;
+               struct strbuf buf = STRBUF_INIT;
+               int i;
+
+               switch (curl_global_sslset(-1, http_ssl_backend, &backends)) {
+               case CURLSSLSET_UNKNOWN_BACKEND:
+                       strbuf_addf(&buf, _("Unsupported SSL backend '%s'. "
+                                           "Supported SSL backends:"),
+                                           http_ssl_backend);
+                       for (i = 0; backends[i]; i++)
+                               strbuf_addf(&buf, "\n\t%s", backends[i]->name);
+                       die("%s", buf.buf);
+               case CURLSSLSET_NO_BACKENDS:
+                       die(_("Could not set SSL backend to '%s': "
+                             "cURL was built without SSL backends"),
+                           http_ssl_backend);
+               case CURLSSLSET_TOO_LATE:
+                       die(_("Could not set SSL backend to '%s': already set"),
+                           http_ssl_backend);
+               case CURLSSLSET_OK:
+                       break; /* Okay! */
+               }
+       }
+#endif
 
        if (curl_global_init(CURL_GLOBAL_ALL) != CURLE_OK)
                die("curl_global_init failed");
@@ -675,8 +1159,10 @@ void http_init(struct remote *remote, const char *url, int proactive_auth)
        if (remote)
                var_override(&http_proxy_authmethod, remote->http_proxy_authmethod);
 
-       pragma_header = curl_slist_append(pragma_header, "Pragma: no-cache");
-       no_pragma_header = curl_slist_append(no_pragma_header, "Pragma:");
+       pragma_header = curl_slist_append(http_copy_default_headers(),
+               "Pragma: no-cache");
+       no_pragma_header = curl_slist_append(http_copy_default_headers(),
+               "Pragma:");
 
 #ifdef USE_CURL_MULTI
        {
@@ -720,6 +1206,13 @@ void http_init(struct remote *remote, const char *url, int proactive_auth)
                max_requests = DEFAULT_MAX_REQUESTS;
 #endif
 
+       set_from_env(&http_proxy_ssl_cert, "GIT_PROXY_SSL_CERT");
+       set_from_env(&http_proxy_ssl_key, "GIT_PROXY_SSL_KEY");
+       set_from_env(&http_proxy_ssl_ca_info, "GIT_PROXY_SSL_CAINFO");
+
+       if (getenv("GIT_PROXY_SSL_CERT_PASSWORD_PROTECTED"))
+               proxy_ssl_cert_password_required = 1;
+
        if (getenv("GIT_CURL_FTP_NO_EPSV"))
                curl_ftp_no_epsv = 1;
 
@@ -743,9 +1236,7 @@ void http_cleanup(void)
        while (slot != NULL) {
                struct active_request_slot *next = slot->next;
                if (slot->curl != NULL) {
-#ifdef USE_CURL_MULTI
-                       curl_multi_remove_handle(curlm, slot->curl);
-#endif
+                       xmulti_remove_handle(slot);
                        curl_easy_cleanup(slot->curl);
                }
                free(slot);
@@ -762,6 +1253,8 @@ void http_cleanup(void)
 #endif
        curl_global_cleanup();
 
+       string_list_clear(&extra_http_headers, 0);
+
        curl_slist_free_all(pragma_header);
        pragma_header = NULL;
 
@@ -775,8 +1268,7 @@ void http_cleanup(void)
 
        if (proxy_auth.password) {
                memset(proxy_auth.password, 0, strlen(proxy_auth.password));
-               free(proxy_auth.password);
-               proxy_auth.password = NULL;
+               FREE_AND_NULL(proxy_auth.password);
        }
 
        free((void *)curl_proxyuserpwd);
@@ -787,13 +1279,17 @@ void http_cleanup(void)
 
        if (cert_auth.password != NULL) {
                memset(cert_auth.password, 0, strlen(cert_auth.password));
-               free(cert_auth.password);
-               cert_auth.password = NULL;
+               FREE_AND_NULL(cert_auth.password);
        }
        ssl_cert_password_required = 0;
 
-       free(cached_accept_language);
-       cached_accept_language = NULL;
+       if (proxy_cert_auth.password != NULL) {
+               memset(proxy_cert_auth.password, 0, strlen(proxy_cert_auth.password));
+               FREE_AND_NULL(proxy_cert_auth.password);
+       }
+       proxy_ssl_cert_password_required = 0;
+
+       FREE_AND_NULL(cached_accept_language);
 }
 
 struct active_request_slot *get_active_slot(void)
@@ -861,13 +1357,23 @@ struct active_request_slot *get_active_slot(void)
        curl_easy_setopt(slot->curl, CURLOPT_FAILONERROR, 1);
        curl_easy_setopt(slot->curl, CURLOPT_RANGE, NULL);
 
+       /*
+        * Default following to off unless "ALWAYS" is configured; this gives
+        * callers a sane starting point, and they can tweak for individual
+        * HTTP_FOLLOW_* cases themselves.
+        */
+       if (http_follow_config == HTTP_FOLLOW_ALWAYS)
+               curl_easy_setopt(slot->curl, CURLOPT_FOLLOWLOCATION, 1);
+       else
+               curl_easy_setopt(slot->curl, CURLOPT_FOLLOWLOCATION, 0);
+
 #if LIBCURL_VERSION_NUM >= 0x070a08
        curl_easy_setopt(slot->curl, CURLOPT_IPRESOLVE, git_curl_ipresolve);
 #endif
 #ifdef LIBCURL_CAN_HANDLE_AUTH_ANY
        curl_easy_setopt(slot->curl, CURLOPT_HTTPAUTH, http_auth_methods);
 #endif
-       if (http_auth.password || curl_empty_auth)
+       if (http_auth.password || curl_empty_auth_enabled())
                init_curl_http_auth(slot->curl);
 
        return slot;
@@ -881,6 +1387,8 @@ int start_active_slot(struct active_request_slot *slot)
 
        if (curlm_result != CURLM_OK &&
            curlm_result != CURLM_CALL_MULTI_PERFORM) {
+               warning("curl_multi_add_handle failed: %s",
+                       curl_multi_strerror(curlm_result));
                active_requests--;
                slot->in_use = 0;
                return 0;
@@ -906,14 +1414,14 @@ static struct fill_chain *fill_cfg;
 
 void add_fill_function(void *data, int (*fill)(void *))
 {
-       struct fill_chain *new = xmalloc(sizeof(*new));
+       struct fill_chain *new_fill = xmalloc(sizeof(*new_fill));
        struct fill_chain **linkp = &fill_cfg;
-       new->data = data;
-       new->fill = fill;
-       new->next = NULL;
+       new_fill->data = data;
+       new_fill->fill = fill;
+       new_fill->next = NULL;
        while (*linkp)
                linkp = &(*linkp)->next;
-       *linkp = new;
+       *linkp = new_fill;
 }
 
 void fill_active_slots(void)
@@ -1020,13 +1528,13 @@ void run_active_slot(struct active_request_slot *slot)
 static void release_active_slot(struct active_request_slot *slot)
 {
        closedown_active_slot(slot);
-       if (slot->curl && curl_session_count > min_curl_sessions) {
-#ifdef USE_CURL_MULTI
-               curl_multi_remove_handle(curlm, slot->curl);
-#endif
-               curl_easy_cleanup(slot->curl);
-               slot->curl = NULL;
-               curl_session_count--;
+       if (slot->curl) {
+               xmulti_remove_handle(slot);
+               if (curl_session_count > min_curl_sessions) {
+                       curl_easy_cleanup(slot->curl);
+                       slot->curl = NULL;
+                       curl_session_count--;
+               }
        }
 #ifdef USE_CURL_MULTI
        fill_active_slots();
@@ -1084,7 +1592,7 @@ void append_remote_object_url(struct strbuf *buf, const char *url,
 
        strbuf_addf(buf, "objects/%.*s/", 2, hex);
        if (!only_two_digit_prefix)
-               strbuf_addf(buf, "%s", hex+2);
+               strbuf_addstr(buf, hex + 2);
 }
 
 char *get_remote_object_url(const char *url, const char *hex,
@@ -1095,26 +1603,35 @@ char *get_remote_object_url(const char *url, const char *hex,
        return strbuf_detach(&buf, NULL);
 }
 
-static int handle_curl_result(struct slot_results *results)
+void normalize_curl_result(CURLcode *result, long http_code,
+                          char *errorstr, size_t errorlen)
 {
        /*
         * If we see a failing http code with CURLE_OK, we have turned off
         * FAILONERROR (to keep the server's custom error response), and should
         * translate the code into failure here.
+        *
+        * Likewise, if we see a redirect (30x code), that means we turned off
+        * redirect-following, and we should treat the result as an error.
         */
-       if (results->curl_result == CURLE_OK &&
-           results->http_code >= 400) {
-               results->curl_result = CURLE_HTTP_RETURNED_ERROR;
+       if (*result == CURLE_OK && http_code >= 300) {
+               *result = CURLE_HTTP_RETURNED_ERROR;
                /*
                 * Normally curl will already have put the "reason phrase"
                 * from the server into curl_errorstr; unfortunately without
                 * FAILONERROR it is lost, so we can give only the numeric
                 * status code.
                 */
-               snprintf(curl_errorstr, sizeof(curl_errorstr),
-                        "The requested URL returned error: %ld",
-                        results->http_code);
+               xsnprintf(errorstr, errorlen,
+                         "The requested URL returned error: %ld",
+                         http_code);
        }
+}
+
+static int handle_curl_result(struct slot_results *results)
+{
+       normalize_curl_result(&results->curl_result, results->http_code,
+                             curl_errorstr, sizeof(curl_errorstr));
 
        if (results->curl_result == CURLE_OK) {
                credential_approve(&http_auth);
@@ -1130,6 +1647,10 @@ static int handle_curl_result(struct slot_results *results)
                } else {
 #ifdef LIBCURL_CAN_HANDLE_AUTH_ANY
                        http_auth_methods &= ~CURLAUTH_GSSNEGOTIATE;
+                       if (results->auth_avail) {
+                               http_auth_methods &= results->auth_avail;
+                               http_auth_methods_restricted = 1;
+                       }
 #endif
                        return HTTP_REAUTH;
                }
@@ -1151,8 +1672,8 @@ int run_one_slot(struct active_request_slot *slot,
 {
        slot->results = results;
        if (!start_active_slot(slot)) {
-               snprintf(curl_errorstr, sizeof(curl_errorstr),
-                        "failed to start HTTP request");
+               xsnprintf(curl_errorstr, sizeof(curl_errorstr),
+                         "failed to start HTTP request");
                return HTTP_START_FAILED;
        }
 
@@ -1160,6 +1681,17 @@ int run_one_slot(struct active_request_slot *slot,
        return handle_curl_result(results);
 }
 
+struct curl_slist *http_copy_default_headers(void)
+{
+       struct curl_slist *headers = NULL;
+       const struct string_list_item *item;
+
+       for_each_string_list_item(item, &extra_http_headers)
+               headers = curl_slist_append(headers, item->string);
+
+       return headers;
+}
+
 static CURLcode curlinfo_strbuf(CURL *curl, CURLINFO info, struct strbuf *buf)
 {
        char *ptr;
@@ -1377,7 +1909,7 @@ static int http_request(const char *url,
 {
        struct active_request_slot *slot;
        struct slot_results results;
-       struct curl_slist *headers = NULL;
+       struct curl_slist *headers = http_copy_default_headers();
        struct strbuf buf = STRBUF_INIT;
        const char *accept_language;
        int ret;
@@ -1410,14 +1942,24 @@ static int http_request(const char *url,
        strbuf_addstr(&buf, "Pragma:");
        if (options && options->no_cache)
                strbuf_addstr(&buf, " no-cache");
-       if (options && options->keep_error)
-               curl_easy_setopt(slot->curl, CURLOPT_FAILONERROR, 0);
+       if (options && options->initial_request &&
+           http_follow_config == HTTP_FOLLOW_INITIAL)
+               curl_easy_setopt(slot->curl, CURLOPT_FOLLOWLOCATION, 1);
 
        headers = curl_slist_append(headers, buf.buf);
 
+       /* Add additional headers here */
+       if (options && options->extra_headers) {
+               const struct string_list_item *item;
+               for_each_string_list_item(item, options->extra_headers) {
+                       headers = curl_slist_append(headers, item->string);
+               }
+       }
+
        curl_easy_setopt(slot->curl, CURLOPT_URL, url);
        curl_easy_setopt(slot->curl, CURLOPT_HTTPHEADER, headers);
-       curl_easy_setopt(slot->curl, CURLOPT_ENCODING, "gzip");
+       curl_easy_setopt(slot->curl, CURLOPT_ENCODING, "");
+       curl_easy_setopt(slot->curl, CURLOPT_FAILONERROR, 0);
 
        ret = run_one_slot(slot, &results);
 
@@ -1460,32 +2002,34 @@ static int http_request(const char *url,
  *
  * Note that this assumes a sane redirect scheme. It's entirely possible
  * in the example above to end up at a URL that does not even end in
- * "info/refs".  In such a case we simply punt, as there is not much we can
- * do (and such a scheme is unlikely to represent a real git repository,
- * which means we are likely about to abort anyway).
+ * "info/refs".  In such a case we die. There's not much we can do, such a
+ * scheme is unlikely to represent a real git repository, and failing to
+ * rewrite the base opens options for malicious redirects to do funny things.
  */
 static int update_url_from_redirect(struct strbuf *base,
                                    const char *asked,
                                    const struct strbuf *got)
 {
        const char *tail;
-       size_t tail_len;
+       size_t new_len;
 
        if (!strcmp(asked, got->buf))
                return 0;
 
        if (!skip_prefix(asked, base->buf, &tail))
-               die("BUG: update_url_from_redirect: %s is not a superset of %s",
+               BUG("update_url_from_redirect: %s is not a superset of %s",
                    asked, base->buf);
 
-       tail_len = strlen(tail);
-
-       if (got->len < tail_len ||
-           strcmp(tail, got->buf + got->len - tail_len))
-               return 0; /* insane redirect scheme */
+       new_len = got->len;
+       if (!strip_suffix_mem(got->buf, &new_len, tail))
+               die(_("unable to update url base from redirection:\n"
+                     "  asked for: %s\n"
+                     "   redirect: %s"),
+                   asked, got->buf);
 
        strbuf_reset(base);
-       strbuf_add(base, got->buf, got->len - tail_len);
+       strbuf_add(base, got->buf, new_len);
+
        return 1;
 }
 
@@ -1495,6 +2039,9 @@ static int http_request_reauth(const char *url,
 {
        int ret = http_request(url, result, target, options);
 
+       if (ret != HTTP_OK && ret != HTTP_REAUTH)
+               return ret;
+
        if (options && options->effective_url && options->base_url) {
                if (update_url_from_redirect(options->base_url,
                                             url, options->effective_url)) {
@@ -1507,19 +2054,26 @@ static int http_request_reauth(const char *url,
                return ret;
 
        /*
-        * If we are using KEEP_ERROR, the previous request may have
-        * put cruft into our output stream; we should clear it out before
-        * making our next request. We only know how to do this for
-        * the strbuf case, but that is enough to satisfy current callers.
+        * The previous request may have put cruft into our output stream; we
+        * should clear it out before making our next request.
         */
-       if (options && options->keep_error) {
-               switch (target) {
-               case HTTP_REQUEST_STRBUF:
-                       strbuf_reset(result);
-                       break;
-               default:
-                       die("BUG: HTTP_KEEP_ERROR is only supported with strbufs");
+       switch (target) {
+       case HTTP_REQUEST_STRBUF:
+               strbuf_reset(result);
+               break;
+       case HTTP_REQUEST_FILE:
+               if (fflush(result)) {
+                       error_errno("unable to flush a file");
+                       return HTTP_START_FAILED;
+               }
+               rewind(result);
+               if (ftruncate(fileno(result), 0) < 0) {
+                       error_errno("unable to truncate a file");
+                       return HTTP_START_FAILED;
                }
+               break;
+       default:
+               BUG("Unknown http_request target");
        }
 
        credential_fill(&http_auth);
@@ -1577,7 +2131,7 @@ int http_fetch_ref(const char *base, struct ref *ref)
        url = quote_ref_url(base, ref->name);
        if (http_get_strbuf(url, &buffer, &options) == HTTP_OK) {
                strbuf_rtrim(&buffer);
-               if (buffer.len == 40)
+               if (buffer.len == the_hash_algo->hexsz)
                        ret = get_oid_hex(buffer.buf, &ref->old_oid);
                else if (starts_with(buffer.buf, "ref: ")) {
                        ref->symref = xstrdup(buffer.buf + 5);
@@ -1591,25 +2145,24 @@ int http_fetch_ref(const char *base, struct ref *ref)
 }
 
 /* Helpers for fetching packs */
-static char *fetch_pack_index(unsigned char *sha1, const char *base_url)
+static char *fetch_pack_index(unsigned char *hash, const char *base_url)
 {
        char *url, *tmp;
        struct strbuf buf = STRBUF_INIT;
 
        if (http_is_verbose)
-               fprintf(stderr, "Getting index for pack %s\n", sha1_to_hex(sha1));
+               fprintf(stderr, "Getting index for pack %s\n", hash_to_hex(hash));
 
        end_url_with_slash(&buf, base_url);
-       strbuf_addf(&buf, "objects/pack/pack-%s.idx", sha1_to_hex(sha1));
+       strbuf_addf(&buf, "objects/pack/pack-%s.idx", hash_to_hex(hash));
        url = strbuf_detach(&buf, NULL);
 
-       strbuf_addf(&buf, "%s.temp", sha1_pack_index_name(sha1));
+       strbuf_addf(&buf, "%s.temp", sha1_pack_index_name(hash));
        tmp = strbuf_detach(&buf, NULL);
 
        if (http_get_file(url, tmp, NULL) != HTTP_OK) {
                error("Unable to get pack index %s", url);
-               free(tmp);
-               tmp = NULL;
+               FREE_AND_NULL(tmp);
        }
 
        free(url);
@@ -1660,10 +2213,11 @@ add_pack:
 int http_get_info_packs(const char *base_url, struct packed_git **packs_head)
 {
        struct http_get_options options = {0};
-       int ret = 0, i = 0;
-       char *url, *data;
+       int ret = 0;
+       char *url;
+       const char *data;
        struct strbuf buf = STRBUF_INIT;
-       unsigned char sha1[20];
+       struct object_id oid;
 
        end_url_with_slash(&buf, base_url);
        strbuf_addstr(&buf, "objects/info/packs");
@@ -1675,24 +2229,17 @@ int http_get_info_packs(const char *base_url, struct packed_git **packs_head)
                goto cleanup;
 
        data = buf.buf;
-       while (i < buf.len) {
-               switch (data[i]) {
-               case 'P':
-                       i++;
-                       if (i + 52 <= buf.len &&
-                           starts_with(data + i, " pack-") &&
-                           starts_with(data + i + 46, ".pack\n")) {
-                               get_sha1_hex(data + i + 6, sha1);
-                               fetch_and_setup_pack_index(packs_head, sha1,
-                                                     base_url);
-                               i += 51;
-                               break;
-                       }
-               default:
-                       while (i < buf.len && data[i] != '\n')
-                               i++;
+       while (*data) {
+               if (skip_prefix(data, "P pack-", &data) &&
+                   !parse_oid_hex(data, &oid, &data) &&
+                   skip_prefix(data, ".pack", &data) &&
+                   (*data == '\n' || *data == '\0')) {
+                       fetch_and_setup_pack_index(packs_head, oid.hash, base_url);
+               } else {
+                       data = strchrnul(data, '\n');
                }
-               i++;
+               if (*data)
+                       data++; /* skip past newline */
        }
 
 cleanup:
@@ -1707,85 +2254,85 @@ void release_http_pack_request(struct http_pack_request *preq)
                preq->packfile = NULL;
        }
        preq->slot = NULL;
+       strbuf_release(&preq->tmpfile);
        free(preq->url);
        free(preq);
 }
 
 int finish_http_pack_request(struct http_pack_request *preq)
 {
-       struct packed_git **lst;
-       struct packed_git *p = preq->target;
-       char *tmp_idx;
-       size_t len;
        struct child_process ip = CHILD_PROCESS_INIT;
-       const char *ip_argv[8];
-
-       close_pack_index(p);
+       int tmpfile_fd;
+       int ret = 0;
 
        fclose(preq->packfile);
        preq->packfile = NULL;
 
-       lst = preq->lst;
-       while (*lst != p)
-               lst = &((*lst)->next);
-       *lst = (*lst)->next;
-
-       if (!strip_suffix(preq->tmpfile, ".pack.temp", &len))
-               die("BUG: pack tmpfile does not end in .pack.temp?");
-       tmp_idx = xstrfmt("%.*s.idx.temp", (int)len, preq->tmpfile);
+       tmpfile_fd = xopen(preq->tmpfile.buf, O_RDONLY);
 
-       ip_argv[0] = "index-pack";
-       ip_argv[1] = "-o";
-       ip_argv[2] = tmp_idx;
-       ip_argv[3] = preq->tmpfile;
-       ip_argv[4] = NULL;
-
-       ip.argv = ip_argv;
+       strvec_push(&ip.args, "index-pack");
+       strvec_push(&ip.args, "--stdin");
        ip.git_cmd = 1;
-       ip.no_stdin = 1;
-       ip.no_stdout = 1;
+       ip.in = tmpfile_fd;
+       if (preq->generate_keep) {
+               strvec_pushf(&ip.args, "--keep=git %"PRIuMAX,
+                            (uintmax_t)getpid());
+               ip.out = 0;
+       } else {
+               ip.no_stdout = 1;
+       }
 
        if (run_command(&ip)) {
-               unlink(preq->tmpfile);
-               unlink(tmp_idx);
-               free(tmp_idx);
-               return -1;
+               ret = -1;
+               goto cleanup;
        }
 
-       unlink(sha1_pack_index_name(p->sha1));
+cleanup:
+       close(tmpfile_fd);
+       unlink(preq->tmpfile.buf);
+       return ret;
+}
 
-       if (finalize_object_file(preq->tmpfile, sha1_pack_name(p->sha1))
-        || finalize_object_file(tmp_idx, sha1_pack_index_name(p->sha1))) {
-               free(tmp_idx);
-               return -1;
-       }
+void http_install_packfile(struct packed_git *p,
+                          struct packed_git **list_to_remove_from)
+{
+       struct packed_git **lst = list_to_remove_from;
 
-       install_packed_git(p);
-       free(tmp_idx);
-       return 0;
+       while (*lst != p)
+               lst = &((*lst)->next);
+       *lst = (*lst)->next;
+
+       install_packed_git(the_repository, p);
 }
 
 struct http_pack_request *new_http_pack_request(
-       struct packed_git *target, const char *base_url)
+       const unsigned char *packed_git_hash, const char *base_url) {
+
+       struct strbuf buf = STRBUF_INIT;
+
+       end_url_with_slash(&buf, base_url);
+       strbuf_addf(&buf, "objects/pack/pack-%s.pack",
+               hash_to_hex(packed_git_hash));
+       return new_direct_http_pack_request(packed_git_hash,
+                                           strbuf_detach(&buf, NULL));
+}
+
+struct http_pack_request *new_direct_http_pack_request(
+       const unsigned char *packed_git_hash, char *url)
 {
        off_t prev_posn = 0;
-       struct strbuf buf = STRBUF_INIT;
        struct http_pack_request *preq;
 
        preq = xcalloc(1, sizeof(*preq));
-       preq->target = target;
+       strbuf_init(&preq->tmpfile, 0);
 
-       end_url_with_slash(&buf, base_url);
-       strbuf_addf(&buf, "objects/pack/pack-%s.pack",
-               sha1_to_hex(target->sha1));
-       preq->url = strbuf_detach(&buf, NULL);
+       preq->url = url;
 
-       snprintf(preq->tmpfile, sizeof(preq->tmpfile), "%s.temp",
-               sha1_pack_name(target->sha1));
-       preq->packfile = fopen(preq->tmpfile, "a");
+       strbuf_addf(&preq->tmpfile, "%s.temp", sha1_pack_name(packed_git_hash));
+       preq->packfile = fopen(preq->tmpfile.buf, "a");
        if (!preq->packfile) {
                error("Unable to open local file %s for pack",
-                     preq->tmpfile);
+                     preq->tmpfile.buf);
                goto abort;
        }
 
@@ -1805,13 +2352,15 @@ struct http_pack_request *new_http_pack_request(
                if (http_is_verbose)
                        fprintf(stderr,
                                "Resuming fetch of pack %s at byte %"PRIuMAX"\n",
-                               sha1_to_hex(target->sha1), (uintmax_t)prev_posn);
+                               hash_to_hex(packed_git_hash),
+                               (uintmax_t)prev_posn);
                http_opt_request_remainder(preq->slot->curl, prev_posn);
        }
 
        return preq;
 
 abort:
+       strbuf_release(&preq->tmpfile);
        free(preq->url);
        free(preq);
        return NULL;
@@ -1824,13 +2373,24 @@ static size_t fwrite_sha1_file(char *ptr, size_t eltsize, size_t nmemb,
        unsigned char expn[4096];
        size_t size = eltsize * nmemb;
        int posn = 0;
-       struct http_object_request *freq =
-               (struct http_object_request *)data;
+       struct http_object_request *freq = data;
+       struct active_request_slot *slot = freq->slot;
+
+       if (slot) {
+               CURLcode c = curl_easy_getinfo(slot->curl, CURLINFO_HTTP_CODE,
+                                               &slot->http_code);
+               if (c != CURLE_OK)
+                       BUG("curl_easy_getinfo for HTTP code failed: %s",
+                               curl_easy_strerror(c));
+               if (slot->http_code >= 300)
+                       return nmemb;
+       }
+
        do {
                ssize_t retval = xwrite(freq->localfile,
                                        (char *) ptr + posn, size - posn);
                if (retval < 0)
-                       return posn;
+                       return posn / eltsize;
                posn += retval;
        } while (posn < size);
 
@@ -1840,18 +2400,18 @@ static size_t fwrite_sha1_file(char *ptr, size_t eltsize, size_t nmemb,
                freq->stream.next_out = expn;
                freq->stream.avail_out = sizeof(expn);
                freq->zret = git_inflate(&freq->stream, Z_SYNC_FLUSH);
-               git_SHA1_Update(&freq->c, expn,
-                               sizeof(expn) - freq->stream.avail_out);
+               the_hash_algo->update_fn(&freq->c, expn,
+                                        sizeof(expn) - freq->stream.avail_out);
        } while (freq->stream.avail_in && freq->zret == Z_OK);
-       return size;
+       return nmemb;
 }
 
 struct http_object_request *new_http_object_request(const char *base_url,
-       unsigned char *sha1)
+                                                   const struct object_id *oid)
 {
-       char *hex = sha1_to_hex(sha1);
-       const char *filename;
-       char prevfile[PATH_MAX];
+       char *hex = oid_to_hex(oid);
+       struct strbuf filename = STRBUF_INIT;
+       struct strbuf prevfile = STRBUF_INIT;
        int prevlocal;
        char prev_buf[PREV_BUF_SIZE];
        ssize_t prev_read = 0;
@@ -1859,46 +2419,47 @@ struct http_object_request *new_http_object_request(const char *base_url,
        struct http_object_request *freq;
 
        freq = xcalloc(1, sizeof(*freq));
-       hashcpy(freq->sha1, sha1);
+       strbuf_init(&freq->tmpfile, 0);
+       oidcpy(&freq->oid, oid);
        freq->localfile = -1;
 
-       filename = sha1_file_name(sha1);
-       snprintf(freq->tmpfile, sizeof(freq->tmpfile),
-                "%s.temp", filename);
+       loose_object_path(the_repository, &filename, oid);
+       strbuf_addf(&freq->tmpfile, "%s.temp", filename.buf);
 
-       snprintf(prevfile, sizeof(prevfile), "%s.prev", filename);
-       unlink_or_warn(prevfile);
-       rename(freq->tmpfile, prevfile);
-       unlink_or_warn(freq->tmpfile);
+       strbuf_addf(&prevfile, "%s.prev", filename.buf);
+       unlink_or_warn(prevfile.buf);
+       rename(freq->tmpfile.buf, prevfile.buf);
+       unlink_or_warn(freq->tmpfile.buf);
+       strbuf_release(&filename);
 
        if (freq->localfile != -1)
                error("fd leakage in start: %d", freq->localfile);
-       freq->localfile = open(freq->tmpfile,
+       freq->localfile = open(freq->tmpfile.buf,
                               O_WRONLY | O_CREAT | O_EXCL, 0666);
        /*
         * This could have failed due to the "lazy directory creation";
         * try to mkdir the last path component.
         */
        if (freq->localfile < 0 && errno == ENOENT) {
-               char *dir = strrchr(freq->tmpfile, '/');
+               char *dir = strrchr(freq->tmpfile.buf, '/');
                if (dir) {
                        *dir = 0;
-                       mkdir(freq->tmpfile, 0777);
+                       mkdir(freq->tmpfile.buf, 0777);
                        *dir = '/';
                }
-               freq->localfile = open(freq->tmpfile,
+               freq->localfile = open(freq->tmpfile.buf,
                                       O_WRONLY | O_CREAT | O_EXCL, 0666);
        }
 
        if (freq->localfile < 0) {
-               error("Couldn't create temporary file %s: %s",
-                     freq->tmpfile, strerror(errno));
+               error_errno("Couldn't create temporary file %s",
+                           freq->tmpfile.buf);
                goto abort;
        }
 
        git_inflate_init(&freq->stream);
 
-       git_SHA1_Init(&freq->c);
+       the_hash_algo->init_fn(&freq->c);
 
        freq->url = get_remote_object_url(base_url, hex, 0);
 
@@ -1906,7 +2467,7 @@ struct http_object_request *new_http_object_request(const char *base_url,
         * If a previous temp file is present, process what was already
         * fetched.
         */
-       prevlocal = open(prevfile, O_RDONLY);
+       prevlocal = open(prevfile.buf, O_RDONLY);
        if (prevlocal != -1) {
                do {
                        prev_read = xread(prevlocal, prev_buf, PREV_BUF_SIZE);
@@ -1923,7 +2484,8 @@ struct http_object_request *new_http_object_request(const char *base_url,
                } while (prev_read > 0);
                close(prevlocal);
        }
-       unlink_or_warn(prevfile);
+       unlink_or_warn(prevfile.buf);
+       strbuf_release(&prevfile);
 
        /*
         * Reset inflate/SHA1 if there was an error reading the previous temp
@@ -1932,13 +2494,13 @@ struct http_object_request *new_http_object_request(const char *base_url,
        if (prev_read == -1) {
                memset(&freq->stream, 0, sizeof(freq->stream));
                git_inflate_init(&freq->stream);
-               git_SHA1_Init(&freq->c);
+               the_hash_algo->init_fn(&freq->c);
                if (prev_posn>0) {
                        prev_posn = 0;
                        lseek(freq->localfile, 0, SEEK_SET);
                        if (ftruncate(freq->localfile, 0) < 0) {
-                               error("Couldn't truncate temporary file %s: %s",
-                                         freq->tmpfile, strerror(errno));
+                               error_errno("Couldn't truncate temporary file %s",
+                                           freq->tmpfile.buf);
                                goto abort;
                        }
                }
@@ -1947,6 +2509,7 @@ struct http_object_request *new_http_object_request(const char *base_url,
        freq->slot = get_active_slot();
 
        curl_easy_setopt(freq->slot->curl, CURLOPT_FILE, freq);
+       curl_easy_setopt(freq->slot->curl, CURLOPT_FAILONERROR, 0);
        curl_easy_setopt(freq->slot->curl, CURLOPT_WRITEFUNCTION, fwrite_sha1_file);
        curl_easy_setopt(freq->slot->curl, CURLOPT_ERRORBUFFER, freq->errorstr);
        curl_easy_setopt(freq->slot->curl, CURLOPT_URL, freq->url);
@@ -1967,6 +2530,7 @@ struct http_object_request *new_http_object_request(const char *base_url,
        return freq;
 
 abort:
+       strbuf_release(&prevfile);
        free(freq->url);
        free(freq);
        return NULL;
@@ -1984,6 +2548,7 @@ void process_http_object_request(struct http_object_request *freq)
 int finish_http_object_request(struct http_object_request *freq)
 {
        struct stat st;
+       struct strbuf filename = STRBUF_INIT;
 
        close(freq->localfile);
        freq->localfile = -1;
@@ -1993,31 +2558,32 @@ int finish_http_object_request(struct http_object_request *freq)
        if (freq->http_code == 416) {
                warning("requested range invalid; we may already have all the data.");
        } else if (freq->curl_result != CURLE_OK) {
-               if (stat(freq->tmpfile, &st) == 0)
+               if (stat(freq->tmpfile.buf, &st) == 0)
                        if (st.st_size == 0)
-                               unlink_or_warn(freq->tmpfile);
+                               unlink_or_warn(freq->tmpfile.buf);
                return -1;
        }
 
        git_inflate_end(&freq->stream);
-       git_SHA1_Final(freq->real_sha1, &freq->c);
+       the_hash_algo->final_fn(freq->real_oid.hash, &freq->c);
        if (freq->zret != Z_STREAM_END) {
-               unlink_or_warn(freq->tmpfile);
+               unlink_or_warn(freq->tmpfile.buf);
                return -1;
        }
-       if (hashcmp(freq->sha1, freq->real_sha1)) {
-               unlink_or_warn(freq->tmpfile);
+       if (!oideq(&freq->oid, &freq->real_oid)) {
+               unlink_or_warn(freq->tmpfile.buf);
                return -1;
        }
-       freq->rename =
-               finalize_object_file(freq->tmpfile, sha1_file_name(freq->sha1));
+       loose_object_path(the_repository, &filename, &freq->oid);
+       freq->rename = finalize_object_file(freq->tmpfile.buf, filename.buf);
+       strbuf_release(&filename);
 
        return freq->rename;
 }
 
 void abort_http_object_request(struct http_object_request *freq)
 {
-       unlink_or_warn(freq->tmpfile);
+       unlink_or_warn(freq->tmpfile.buf);
 
        release_http_object_request(freq);
 }
@@ -2028,14 +2594,12 @@ void release_http_object_request(struct http_object_request *freq)
                close(freq->localfile);
                freq->localfile = -1;
        }
-       if (freq->url != NULL) {
-               free(freq->url);
-               freq->url = NULL;
-       }
+       FREE_AND_NULL(freq->url);
        if (freq->slot != NULL) {
                freq->slot->callback_func = NULL;
                freq->slot->callback_data = NULL;
                release_active_slot(freq->slot);
                freq->slot = NULL;
        }
+       strbuf_release(&freq->tmpfile);
 }