#!/bin/sh # git-remote-gcrypt # # git-remote-gcrypt is licensed under the terms of the GNU GPL version 3 # (or at your option, version 2, or any version later than GPLv3). # See http://www.gnu.org/licenses/ for more information. # # See README set -e set -u Localdir="${GIT_DIR:=.git}/remote-gcrypt" export GITCEPTION="${GITCEPTION:-}+" # Reuse $Gref except when stacked Gref="refs/gcrypt/gitception$GITCEPTION" Gref_rbranch="refs/heads/master" Packkey_bytes=33 # 33 random bytes for passphrase, still compatible if changed Hashtype=SHA256 # SHA512 SHA384 SHA256 SHA224 supported. Packpat="pack :*:" Manifestfile=91bd0c092128cf2e60e1a608c31e92caf1f9c1595f83f2890ef17c0e4881aa0a Did_find_repo= # yes for connected, no for no repo Repoid= Branchlist= Packlist= Keeplist= Extension_list= Repack_limit=25 Recipients= # compat/utility functions xecho() { cat <&2; } echo_die() { echo_info "$@" ; exit 1; } isnull() { case "$1" in "") return 0;; *) return 1;; esac; } isnonnull() { ! isnull "$1"; } iseq() { case "$1" in "$2") return 0;; *) return 1;; esac; } isnoteq() { ! iseq "$@"; } isurl() { isnull "${2%%$1://*}"; } islocalrepo() { isnull "${1##/*}" && [ ! -e "$1/HEAD" ]; } xgrep() { command grep "$@" || : ; } sort_C() { LC_ALL=C command sort "$@"; } sort_stable_k2() { awk '{ printf("%08d\t%s\n", NR, $0) }' | sort_C -k 3,3 -k 1,1 |cut -f 2- } tac() { sed '1!G;h;$!d'; } # setvar is used for named return variables # $1 *must* be a valid variable name, $2 is any value setvar() { eval $1=\$2 } Newline=" " # $1 is return var, $2 is value appended with newline separator append_to() { local tmp_= eval tmp_=\$$1 isnull "$tmp_" || tmp_=$tmp_$Newline setvar "$1" "$tmp_$2" } # Split $1 into $2:$3 splitcolon() { setvar "$2" "${1%%:*}" setvar "$3" "${1#*:}" } ## gitception part # Fetch giturl $1, file $2 gitception_get() { # Take care to preserve FETCH_HEAD local ret_=: obj_id= f_head="$GIT_DIR/FETCH_HEAD" [ -e "$f_head" ] && command mv -f "$f_head" "$f_head.$$~" || : git fetch -q -f "$1" "$Gref_rbranch:$Gref" >/dev/null && obj_id="$(git ls-tree "$Gref" | xgrep -E '\b'"$2"'$' | awk '{print $3}')" && isnonnull "$obj_id" && git cat-file blob "$obj_id" && ret_=: || { ret_=false && : ; } [ -e "$f_head.$$~" ] && command mv -f "$f_head.$$~" "$f_head" || : $ret_ } anon_commit() { GIT_AUTHOR_NAME="root" GIT_AUTHOR_EMAIL="root@localhost" \ GIT_AUTHOR_DATE="1356994801 -0400" GIT_COMMITTER_NAME="root" \ GIT_COMMITTER_EMAIL="root@localhost" \ GIT_COMMITTER_DATE="1356994801 -0400" \ git commit-tree "$@" </dev/null >&2 || : git rev-parse -q --verify "$Gref" >/dev/null && return 0 || commit_id=$(anon_commit "$empty_tree") && git update-ref "$Gref" "$commit_id" } ## end gitception # Fetch repo $1, file $2, tmpfile in $3 GET() { if isurl sftp "$1" then (exec 0>&-; curl -s -S -k "$1/$2") > "$3" elif isurl rsync "$1" then (exec 0>&-; rsync -I -W "${1#rsync://}"/"$2" "$3" >&2) elif islocalrepo "$1" then cat "$1/$2" > "$3" else gitception_get "${1#gitception://}" "$2" > "$3" fi } # Put repo $1, file $2 or fail, tmpfile in $3 PUT() { if isurl sftp "$1" then curl -s -S -k --ftp-create-dirs -T "$3" "$1/$2" elif isurl rsync "$1" then rsync -I -W "$3" "${1#rsync://}"/"$2" >&2 elif islocalrepo "$1" then cat > "$1/$2" < "$3" else gitception_put "${1#gitception://}" "$2" < "$3" fi } # Put all PUT changes for repo $1 at once PUT_FINAL() { if isurl sftp "$1" || islocalrepo "$1" || isurl rsync "$1" then : else git push --quiet -f "${1#gitception://}" "$Gref:$Gref_rbranch" fi } # Put directory for repo $1 PUTREPO() { if isurl sftp "$1" then : elif isurl rsync "$1" then rsync -q -r --exclude='*' "$Localdir/" "${1#rsync://}" >&2 elif islocalrepo "$1" then mkdir -p "$1" else gitception_new_repo "${1#gitception://}" fi } # For repo $1, delete all newline-separated files in $2 REMOVE() { local fn_= if isurl sftp "$1" then # FIXME echo_info "sftp: Ignore remove request $1/$2" elif isurl rsync "$1" then xecho "$2" | rsync -I -W -v -r --delete --include-from=- \ --exclude='*' "$Localdir"/ "${1#rsync://}/" >&2 elif islocalrepo "$1" then for fn_ in $2; do rm -f "$1"/"$fn_" done else for fn_ in $2; do gitception_remove "${1#gitception://}" "$fn_" done fi } CLEAN_FINAL() { if isurl sftp "$1" || islocalrepo "$1" || isurl rsync "$1" then : else git update-ref -d "$Gref" || : fi } addsignkeyparam() { if isnull "$Conf_signkey"; then "$@" else "$@" -u "$Conf_signkey" fi } ENCRYPT() { gpg --batch --force-mdc --compress-algo none --passphrase-fd 3 -c 3<&1 && status_=$(gpg --status-fd 3 -q -d 3>&1 1>&4) && xecho "$status_" | grep "^\[GNUPG:\] ENC_TO " >/dev/null && (xecho "$status_" | grep -e "$1" >/dev/null || { echo_info "Failed to verify manifest signature!" && echo_info "Only accepting signatories: ${2:-(none)}" && return 1 }) } # Generate $1 random bytes genkey() { gpg --armor --gen-rand 1 "$1" } gpg_hash() { local hash_= hash_=$(gpg --with-colons --print-md "$1" | tr A-F a-f) hash_=${hash_#:*:} xecho "${hash_%:}" } pack_hash() { gpg_hash "$Hashtype"; } # Pass the branch/ref by pipe to git safe_git_rev_parse() { git cat-file --batch-check 2>/dev/null | xgrep -v "missing" | cut -f 1 -d ' ' } make_new_repo() { echo_info "Setting up new repository" PUTREPO "$URL" # Needed assumption: the same user should have no duplicate Repoid Repoid=":id:$(genkey 15)" iseq "${NAME#gcrypt::}" "$URL" || git config "remote.$NAME.gcrypt-id" "$Repoid" echo_info "Remote ID is $Repoid" Extension_list=$(xecho "extn comment") } # $1 return var for goodsig match, $2 return var for signers text read_config() { local recp_= key_line= cap_= conf_keyring= conf_part= good_sig= signers_= Conf_signkey=$(git config --path user.signingkey || :) conf_keyring=$(git config --path gcrypt.keyring || :) conf_part=$(git config --get "remote.$NAME.gcrypt-participants" '.+' || git config --get gcrypt.participants '.+' || :) # Figure out which keys we should encrypt to or accept signatures from if isnonnull "$conf_keyring" && isnull "$conf_part" then echo_info "WARNING: Setting gcrypt.keyring is deprecated," \ "use gcrypt.participants instead." conf_part=$(gpg --no-default-keyring --keyring "$conf_keyring" \ --with-colons --fast-list -k | grep ^pub | cut -f 5 -d :) fi if isnull "$conf_part" || iseq "$conf_part" simple then signers_="(default keyring)" Recipients="--throw-keyids --default-recipient-self" good_sig="^\[GNUPG:\] GOODSIG " setvar "$1" "$good_sig" setvar "$2" "$signers_" return 0 fi for recp_ in $conf_part do key_line=$(gpg --with-colons --fast-list -k "$recp_" | xgrep ^pub) isnonnull "${key_line##*"$Newline"*}" || echo_info "WARNING: '$recp_' matches multiple keys, using one" key_line=${key_line%%"$Newline"*} keyid_=$(xecho "$key_line" | cut -f 5 -d :) isnonnull "$keyid_" && signers_="$signers_ $keyid_" && append_to good_sig "^\[GNUPG:\] GOODSIG $keyid_" || { echo_info "WARNING: Skipping missing key $recp_" continue } # Check 'E'ncrypt capability cap_=$(xecho "$key_line" | cut -f 12 -d :) iseq "${cap_#*E}" "$cap_" || Recipients="$Recipients -R $keyid_" done if isnull "$Recipients" then echo_info "You have not configured any keys you can encrypt to" \ "for this repository" echo_info "Use ::" echo_info " git config gcrypt.participants YOURKEYID" exit 1 fi setvar "$1" "$good_sig" setvar "$2" "$signers_" } ensure_connected() { local manifest_= rcv_repoid= r_name= url_frag= sig_match= signer_text= if isnonnull "$Did_find_repo" then return fi Did_find_repo=no read_config sig_match signer_text iseq "${NAME#gcrypt::}" "$URL" || r_name=$NAME # Fixup ssh:// -> rsync:// if isurl ssh "$URL"; then URL="rsync://${URL#ssh://}" isnull "$r_name" || { git config "remote.$r_name.url" "gcrypt::$URL" echo_info "Updated URL for $r_name, ssh: -> rsync:" } fi if isurl gitception "$URL" && isnonnull "$r_name"; then git config "remote.$r_name.url" "gcrypt::${URL#gitception://}" echo_info "Updated URL for $r_name, gitception:// -> ()" fi # Find the URL fragment url_frag=${URL##*"#"} isnoteq "$url_frag" "$URL" || url_frag= isnonnull "$url_frag" || { # find old style /G.XXXXXX fragment url_frag=${URL##*/G.} if isnoteq "$url_frag" "$URL"; then URL=${URL%/G."$url_frag"} isnull "$r_name" || { git config "remote.$r_name.url" \ "gcrypt::$URL#$url_frag" echo_info "Updated URL for $r_name, use #fragment" } else url_frag= fi } URL=${URL%"#$url_frag"} # manifestfile -- sha224 hash if we can, else the default location if isurl sftp "$URL" || islocalrepo "$URL" || isurl rsync "$URL" then # not for gitception isnull "$url_frag" || Manifestfile=$(xecho_n "$url_frag" | gpg_hash SHA224) else isnull "$url_frag" || Gref_rbranch="refs/heads/$url_frag" fi Repoid= isnull "$r_name" || Repoid=$(git config "remote.$r_name.gcrypt-id" || :) TmpManifest_Enc="$Localdir/tmp_manifest.$$" GET "$URL" "$Manifestfile" "$TmpManifest_Enc" 2>/dev/null || { echo_info "Repository not found: $URL" return 0 } Did_find_repo=yes echo_info "Decrypting manifest" manifest_=$(PRIVDECRYPT "$sig_match" "$signer_text" < "$TmpManifest_Enc") && isnonnull "$manifest_" || echo_die "Failed to decrypt manifest!" rm -f "$TmpManifest_Enc" Branchlist=$(xecho "$manifest_" | xgrep -E '^[0-9a-f]{40} ') Packlist=$(xecho "$manifest_" | xgrep "^pack ") Keeplist=$(xecho "$manifest_" | xgrep "^keep ") Extension_list=$(xecho "$manifest_" | xgrep "^extn ") rcv_repoid=$(xecho "$manifest_" | xgrep "^repo ") rcv_repoid=${rcv_repoid#repo } rcv_repoid=${rcv_repoid% *} if isnull "$Repoid" then echo_info "Remote ID is $rcv_repoid" Repoid=$rcv_repoid elif isnoteq "$rcv_repoid" "$Repoid" then echo_info "WARNING:" echo_info "WARNING: Remote ID has changed!" echo_info "WARNING: from $Repoid" echo_info "WARNING: to $rcv_repoid" echo_info "WARNING:" Repoid=$rcv_repoid else return 0 fi isnull "$r_name" || git config "remote.$r_name.gcrypt-id" "$rcv_repoid" } # $1 is the packline pack :SHA256:abc1231.. fetch_decrypt_pack() { local key_= rcv_id= htype_= pack_= hfunc_= splitcolon "${1#pack :}" htype_ pack_ if isnoteq "$htype_" SHA256 && isnoteq "$htype_" SHA224 && isnoteq "$htype_" SHA384 && isnoteq "$htype_" SHA512 then echo_die "Packline malformed: $1" fi GET "$URL" "$pack_" "$TmpPack_Encrypted" && rcv_id=$(gpg_hash "$htype_" < "$TmpPack_Encrypted") && iseq "$rcv_id" "$pack_" || echo_die "Packfile $pack_ does not match digest!" key_=$(xecho "$Packlist" | grep "$pack_" | cut -f 3 -d ' ') DECRYPT "$key_" < "$TmpPack_Encrypted" } # $1 is new pack id $2 key, $3, $4 return variables # set $3 to yes if repacked # $4 to list of packfiles to delete repack_if_needed() { local pack_= packline_= premote_= key_= pkeep_= n_= # $TmpPack_Encrypted set in caller setvar "$3" no isnonnull "$Packlist" || return 0 if isnonnull "${GCRYPT_FULL_REPACK:-}" then Keeplist= Repack_limit=1 fi premote_=$(xecho "$Packlist" | cut -f 1-2 -d ' ') pkeep_=$(xecho "$Keeplist" | cut -f 2 -d ' ') if isnull "$pkeep_"; then n_=$(xecho "$Packlist" | wc -l) else n_=$(xecho "$Packlist" | grep -v -e "$pkeep_" | wc -l) fi if [ $Repack_limit -gt "$n_" ]; then return fi echo_info "Repacking remote $NAME, ..." rm -r -f "$Localdir/pack" mkdir -p "$Localdir/pack" DECRYPT "$2" < "$TmpPack_Encrypted" | git index-pack -v --stdin "$Localdir/pack/${1}.pack" >/dev/null xecho "$premote_" | while read packline_ do isnonnull "$packline_" || continue if isnonnull "$pkeep_" && xecho "$packline_" | grep -q -e "$pkeep_" then continue fi pack_=${packline_#$Packpat} fetch_decrypt_pack "$packline_" | git index-pack -v --stdin "$Localdir/pack/${pack_}.pack" >/dev/null done key_=$(genkey "$Packkey_bytes") git verify-pack -v "$Localdir"/pack/*.idx | grep -E '^[0-9a-f]{40}' | cut -f 1 -d ' ' | GIT_ALTERNATE_OBJECT_DIRECTORIES=$Localdir \ git pack-objects --stdout | ENCRYPT "$key_" > "$TmpPack_Encrypted" # Truncate packlist to only the kept packs if isnull "$pkeep_"; then setvar "$4" "$premote_" Packlist= else setvar "$4" "$(xecho "$premote_" | xgrep -v -e "$pkeep_")" Packlist=$(xecho "$Packlist" | xgrep -e "$pkeep_") fi pack_id=$(pack_hash < "$TmpPack_Encrypted") append_to Packlist "pack :${Hashtype}:$pack_id $key_" append_to Keeplist "keep :${Hashtype}:$pack_id 1" rm -r -f "$Localdir/pack" setvar "$3" yes } do_capabilities() { echo_git fetch echo_git push echo_git } do_list() { local obj_id= ref_name= line_= ensure_connected xecho "$Branchlist" | while read line_ do isnonnull "$line_" || break obj_id=${line_%% *} ref_name=${line_##* } echo_git "$obj_id" "$ref_name" if iseq "$ref_name" "refs/heads/master" then echo_git "@refs/heads/master HEAD" fi done # end with blank line echo_git } do_fetch() { # The PACK id is the hash of the encrypted git packfile. # We only download packs mentioned in the encrypted manifest, # and check their digest when received. local pack_= packline_= pneed_= premote_= ensure_connected if isnull "$Packlist" then echo_git # end with blank line return fi TmpPack_Encrypted="$Localdir/tmp_pack_ENCRYPTED_.$$" # The `+` for $GITCEPTION is pointless but we will be safe for stacking premote_=$(xecho "$Packlist" | cut -f 1-2 -d ' ') if [ -s "$Localdir/have_packs+" ] then pneed_="$(xecho "$premote_" | xgrep -v -x -f "$Localdir/have_packs+")" else pneed_=$premote_ fi xecho "$pneed_" | while read packline_ do isnonnull "$packline_" || continue fetch_decrypt_pack "$packline_" | git index-pack -v --stdin >/dev/null # add to local pack list xecho "${packline_}" >> "$Localdir/have_packs$GITCEPTION" done rm -f "$TmpPack_Encrypted" echo_git # end with blank line } # do_push PUSHARGS (multiple lines like +src:dst, with both + and src opt.) do_push() { # Security protocol: # Each git packfile is encrypted and then named for the encrypted # file's hash. The manifest is updated with the pack id. # The manifest is encrypted. local rev_list= src_= dst_= line_= pack_id= key_= obj_= \ did_repack= pack_delete= \ del_hash=xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx ensure_connected if iseq "$Did_find_repo" "no" then make_new_repo fi if isnonnull "$Branchlist" then # mark all remote refs with ^ (if sha-1 exists locally) rev_list=$(xecho "$Branchlist" | cut -f 1 -d ' ' | safe_git_rev_parse | sed -e 's/^\(.\)/^&/') fi while read line_ # from << do # +src:dst -- remove leading + then split at : splitcolon "${line_#+}" src_ dst_ if isnonnull "$src_" then append_to rev_list "$src_" obj_=$(xecho "$src_" | safe_git_rev_parse) else obj_=$del_hash # Mark for deletion fi append_to Branchlist "$obj_ $dst_" done <"$TmpPack_Encrypted" # Only send pack if we have any objects to send if [ -s "$TmpObjlist" ] then pack_id=$(pack_hash < "$TmpPack_Encrypted") repack_if_needed "$pack_id" "$key_" did_repack pack_delete if isnoteq "$did_repack" yes then append_to Packlist "pack :${Hashtype}:$pack_id $key_" fi # else, repack rewrote Packlist fi # Generate manifest echo_info "Encrypting to: $Recipients" echo_info "Requesting manifest signature" TmpManifest_Enc="$Localdir/tmp_manifest.$$" PRIVENCRYPT "$Recipients" > "$TmpManifest_Enc" <&2 } # handle git-remote-helpers protocol gcrypt_main_loop() { local input_= input_inner= args_= NAME=$1 # Remote name URL=$2 # Remote URL mkdir -p "$Localdir" trap cleanup_atexit EXIT 1 2 3 15 echo_info "Development version -- Repository format MAY CHANGE" while read input_ do case "$input_" in capabilities) do_capabilities ;; list|list\ for-push) do_list ;; fetch\ *) args_="${input_##fetch }" while read input_inner do case "$input_inner" in fetch*) args_= #ignored ;; *) break ;; esac done do_fetch "$args_" ;; push\ *) args_="${input_##push }" while read input_inner do case "$input_inner" in push\ *) append_to args_ "${input_inner#push }" ;; *) break ;; esac done do_push "$args_" ;; ?*) echo_die "Unknown input!" ;; *) CLEAN_FINAL "$URL" exit 0 ;; esac done } gcrypt_main_loop "$@"