Ready to upload

1 files changed, 264 insertions, 0 deletions

@@ -0,0 +1,264 @@
+#!/usr/bin/env bash
+# bollux: bash gemini client
+# Author: Case Duckworth <acdw@acdw.net>
+# License: MIT
+# Version: -0.9
+
+PRGN="${0##*/}"
+PORT=1965
+LOG_LEVEL=3 # higher=more important.
+
+clean() {
+        # '\e[?7h': re-enable line wrapping
+        # '\e[2J': clear the screen
+        # '\e[;r': reset the scroll area
+        # '\e[?1049l': swap back to primary screen
+        printf '\e[?7h\e[2J\e[;r\e[?1049l'
+        exit
+}
+
+refresh() {
+        # grab the terminal size
+        shopt -s checkwinsize
+        (
+                :
+                :
+        )
+        # '\e[?1049h': Swap to the alternate buffer.
+        # '\e[?7l':    Disable line wrapping.
+        # '\e[2J':    Clear the screen.
+        # '\e[3;%sr':  Set the scroll area.
+        # '\e[999H':   Move the cursor to the bottom.
+        printf '\e[?1049h\e[?7l\e[2J\e[3;%sr\e[999H' "$((LINES - 1))"
+}
+
+resize() {
+        refresh
+        # '\e7':     Save the cursor position.
+    # '\e[?25l': Hide the cursor.
+    # '\r':      Move the cursor to column 0.
+    # '\e[999B': Move the cursor to the bottom.
+    # '\e[A':    Move the cursor up a line.
+    printf '\e7\e[?25l\r\e[999B\e[A'
+}
+
+bollux() {
+        if [[ -n "$1" ]]; then
+                loc="$1"
+        else
+                read -rp "GO> " loc
+        fi
+
+        log 2 "location:        $loc"
+        log 2 "address: $(address "$loc")"
+        log 2 "server:          $(server "$loc")"
+
+        address "$loc" |
+                download "$(server "$loc")" |
+                handle
+}
+
+log() {
+        case "$1" in
+        [0-9]*)
+                lvl="$1"
+                shift
+                ;;
+        *) lvl=5 ;;
+        esac
+        if ((lvl >= LOG_LEVEL)); then
+                if [[ "$2" == - ]]; then
+                        while IFS= read -r line; do
+                                printf '\e[33m%s\e[0m:\t%s\n' "$PRGN" "$line" >&2
+                        done
+                else
+                        printf '\e[34m%s\e[0m:\t%s\n' "bollux" "$*" >&2
+                fi
+        fi
+}
+
+download() {
+        # usage:
+        #       echo REQUEST | download SERVER
+        #       download SERVER REQUEST
+        serv="$1"
+        req=
+        if (($# == 2)); then
+                req="$2"
+        else
+                req="$(cat)"
+        fi
+        t="$(mktemp)"
+        openssl s_client -crlf -ign_eof -quiet -connect "$serv" <<<"$req" 2>"$t"
+        log 1 <"$t"
+        rm "$t"
+}
+
+address() {
+        addr="$1"
+        if [[ "$addr" != gemini://* ]]; then
+                addr="gemini://$addr"
+        fi
+        echo "$addr" | trim
+}
+
+server() {
+        serv="${1#*://}"
+        serv="${serv%%/*}"
+        if [[ "$serv" != *:* ]]; then
+                serv="$serv:$PORT"
+        fi
+        echo "$serv" | trim
+}
+
+trim() {
+        sed -e 's/^[[:space:]]*//' -e 's/[[:space:]]*$//'
+}
+
+display() {
+        echo
+        cat
+        echo
+}
+
+handle() {
+        # cf. gemini://gemini.circumlunar.space/docs/spec-spec.txt
+        resp="$(cat)"
+        head="$(head -n1 <<<"$resp")"
+        body="$(tail -n+2 <<<"$resp")"
+        stat="$(awk '{print $1}' <<<"$head")"
+        smsg="$(
+                awk '{for(i=2;i<=NF;i++)printf "%s ",$i;printf "\n";}' <<<"$head"
+        )"
+
+        log "[$stat]    $smsg"
+
+        case "$stat" in
+        10) # INPUT
+                #       As per definition of single-digit code 1 in 1.3.2.
+                NOT_IMPLEMENTED
+                ;;
+        20) # SUCCESS
+                #       As per definition of single-digit code 2 in 1.3.2.
+                display <<<"$body"
+                ;;
+        21) # SUCCESS - END OF CLIENT CERTIFICATE SESSION
+                #       The request was handled successfully and a response body will
+                #       follow the response header.  The <META> line is a MIME media
+                #       type which applies to the response body.  In addition, the
+                #       server is signalling the end of a transient client certificate
+                #       session which was previously initiated with a status 61
+                #       response.  The client should immediately and permanently
+                #       delete the certificate and accompanying private key which was
+                #       used in this request.
+                display <<<"$body"
+                NOT_FULLY_IMPLEMENTED
+                ;;
+        30) # REDIRECT - TEMPORARY
+                #       As per definition of single-digit code 3 in 1.3.2.
+                exec "$0" "$smsg"
+                ;;
+        31) # REDIRECT - PERMANENT
+                #       The requested resource should be consistently requested from
+                #       the new URL provided in future.  Tools like search engine
+                #       indexers or content aggregators should update their
+                #       configurations to avoid requesting the old URL, and end-user
+                #       clients may automatically update bookmarks, etc.  Note that
+                #       clients which only pay attention to the initial digit of
+                #       status codes will treat this as a temporary redirect.  They
+                #       will still end up at the right place, they just won't be able
+                #       to make use of the knowledge that this redirect is permanent,
+                #       so they'll pay a small performance penalty by having to follow
+                #       the redirect each time.
+                exec "$0" "$smsg"
+                NOT_FULLY_IMPLEMENTED
+                ;;
+        4*) # 40 - TEMPORARY FAILURE
+                #       As per definition of single-digit code 4 in 1.3.2.
+                # 41 - SERVER UNAVAILABLE
+                #       The server is unavailable due to overload or maintenance.
+                #       (cf HTTP 503)
+                # 42 - CGI ERROR
+                #       A CGI process, or similar system for generating dynamic
+                #       content, died unexpectedly or timed out.
+                # 43 - PROXY ERROR
+                #       A proxy request failed because the server was unable to
+                #       successfully complete a transaction with the remote host.
+                #       (cf HTTP 502, 504)
+                # 44 - SLOW DOWN
+                #       Rate limiting is in effect.  <META> is an integer number of
+                #       seconds which the client must wait before another request is
+                #       made to this server.
+                #       (cf HTTP 429)
+                printf 'OH SHIT!\n%s\t%s\n' "$stat" "$smsg" >&2
+                NOT_IMPLEMENTED
+                ;;
+        5*) # 50 - PERMANENT FAILURE
+                #       As per definition of single-digit code 5 in 1.3.2.
+                # 51 - NOT FOUND
+                #       The requested resource could not be found but may be available
+                #       in the future.
+                #       (cf HTTP 404)
+                #       (struggling to remember this important status code?  Easy:
+                #       you can't find things hidden at Area 51!)
+                # 52 - GONE
+                #       The resource requested is no longer available and will not be
+                #       available again.  Search engines and similar tools should
+                #       remove this resource from their indices.  Content aggregators
+                #       should stop requesting the resource and convey to their human
+                #       users that the subscribed resource is gone.
+                #       (cf HTTP 410)
+                # 53 - PROXY REQUEST REFUSED
+                #       The request was for a resource at a domain not served by the
+                #       server and the server does not accept proxy requests.
+                # 59 - BAD REQUEST
+                #       The server was unable to parse the client's request,
+                #       presumably due to a malformed request.
+                #       (cf HTTP 400)
+                printf 'OH SHIT!\n%s\t%s\n' "$stat" "$smsg" >&2
+                NOT_IMPLEMENTED
+                ;;
+        6*) # 60 - CLIENT CERTIFICATE REQUIRED
+                #       As per definition of single-digit code 6 in 1.3.2.
+                # 61 - TRANSIENT CERTIFICATE REQUESTED
+                #       The server is requesting the initiation of a transient client
+                #       certificate session, as described in 1.4.3.  The client should
+                #       ask the user if they want to accept this and, if so, generate
+                #       a disposable key/cert pair and re-request the resource using it.
+                #       The key/cert pair should be destroyed when the client quits,
+                #       or some reasonable time after it was last used (24 hours?
+                #       Less?)
+                # 62 - AUTHORISED CERTIFICATE REQUIRED
+                #       This resource is protected and a client certificate which the
+                #       server accepts as valid must be used - a disposable key/cert
+                #       generated on the fly in response to this status is not
+                #       appropriate as the server will do something like compare the
+                #       certificate fingerprint against a white-list of allowed
+                #       certificates.  The client should ask the user if they want to
+                #       use a pre-existing certificate from a stored "key chain".
+                # 63 - CERTIFICATE NOT ACCEPTED
+                #       The supplied client certificate is not valid for accessing the
+                #       requested resource.
+                # 64 - FUTURE CERTIFICATE REJECTED
+                #       The supplied client certificate was not accepted because its
+                #       validity start date is in the future.
+                # 65 - EXPIRED CERTIFICTE REJECTED
+                #       The supplied client certificate was not accepted because its
+                #       expiry date has passed.
+                printf 'OH SHIT!\n%s\t%s\n' "$stat" "$smsg" >&2
+                NOT_IMPLEMENTED
+                ;;
+        esac
+}
+
+NOT_IMPLEMENTED() {
+        log "NOT IMPLEMENTED!!!" >&2
+        exit 127
+}
+NOT_FULLY_IMPLEMENTED() {
+        log "NOT FULLY IMPLEMENTED!!!" >&2
+}
+
+if [[ "${BASH_SOURCE[0]}" == "$0" ]]; then
+        bollux "$@"
+fi