s3

   1 #!/bin/bash
   2 # basic amazon s3 operations
   3 # Licensed under the terms of the GNU GPL v2
   4 # Copyright 2007 Victor Lowther <victor.lowther@gmail.com>
   5
   6 HMAC=$(dirname $0)/s3-hmac
   7
   8 # print a message and bail
   9 die() {
  10   echo $*
  11   exit 1
  12 }
  13
  14 # check to see if the variable name passed exists and holds a value.
  15 # Die if it does not.
  16 check_or_die() {
  17   [[ ${!1} ]] || die "Environment variable ${1} is not set."
  18 }
  19
  20 # check to see if we have all the needed S3 variables defined.
  21 # Bail if we do not.
  22 check_s3() {
  23   local sak x
  24   for x in S3_ACCESS_KEY_ID S3_SECRET_ACCESS_KEY; do
  25     check_or_die ${x};
  26   done
  27   [[ -f ${S3_SECRET_ACCESS_KEY} ]] || die "S3_SECRET_ACCESS_KEY must point to a file!"
  28   sak="$(wc -c "${S3_SECRET_ACCESS_KEY}")"
  29   (( ${sak%%[!0-9 ]*} == 40 )) || \
  30     die "S3 Secret Access Key is not exactly 40 bytes long.  Please fix it."
  31 }
  32 # check to see if our external dependencies exist
  33 check_dep() {
  34   local res=0
  35   while [[ $# -ne 0 ]]; do
  36     which "${1}" >& /dev/null || { res=1; echo "${1} not found."; }
  37     shift
  38   done
  39   (( res == 0 )) || die "aborting."
  40 }
  41
  42 check_hmac() {
  43   if test ! -f $HMAC || test ! -x $HMAC; then
  44     die "hmac script not found or not executable."
  45   fi
  46 }
  47
  48 check_deps() {
  49   check_dep openssl date cat grep curl
  50   check_hmac
  51   check_s3
  52 }
  53
  54 urlenc() {
  55   # $1 = string to url encode
  56   # output is on stdout
  57   # we don't urlencode everything, just enough stuff.
  58   echo -n "${1}" |
  59   sed 's/%/%25/g
  60        s/ /%20/g
  61        s/#/%23/g
  62        s/\$/%24/g
  63        s/\&/%26/g
  64        s/+/%2b/g
  65        s/,/%2c/g
  66        s/:/%3a/g
  67        s/;/%3b/g
  68        s/?/%3f/g
  69        s/@/%40/g
  70        s/       /%09/g'
  71 }
  72
  73 xmldec() {
  74   # no parameters.
  75   # accept input on stdin, put it on stdout.
  76   # patches accepted to get more stuff
  77   sed 's/\&quot;/\"/g
  78        s/\&amp;/\&/g
  79        s/\&lt;/</g
  80        s/\&gt;/>/g'
  81 }
  82
  83 ## basic S3 functionality.  x-amz-header functionality is not implemented.
  84 # make an S3 signature string, which will be output on stdout.
  85 s3_signature_string() {
  86   # $1 = HTTP verb
  87   # $2 = date string, must be in UTC
  88   # $3 = bucket name, if any
  89   # $4 = resource path, if any
  90   # $5 = content md5, if any
  91   # $6 = content MIME type, if any
  92   # $7 = canonicalized headers, if any
  93   # signature string will be output on stdout
  94   local verr="Must pass a verb to s3_signature_string!"
  95   local verb="${1:?verr}"
  96   local bucket="${3}"
  97   local resource="${4}"
  98   local derr="Must pass a date to s3_signature_string!"
  99   local date="${2:?derr}"
 100   local mime="${6}"
 101   local md5="${5}"
 102   local headers="${7}"
 103   printf "%s\n%s\n%s\n%s\n%s%s%s" \
 104     "${verb}" "${md5}" "${mime}" "${date}" \
 105     "${headers}" "${bucket}" "${resource}" | \
 106     $HMAC sha1 "${S3_SECRET_ACCESS_KEY}" | openssl base64 -e -a
 107 }
 108
 109 # cheesy, but it is the best way to have multiple headers.
 110 curl_headers() {
 111   # each arg passed will be output on its own line
 112   local parms=$#
 113   for ((;$#;)); do
 114     echo "header = \"${1}\""
 115     shift
 116   done
 117 }
 118
 119 s3_curl() {
 120   # invoke curl to do all the heavy HTTP lifting
 121   # $1 = method (one of GET, PUT, or DELETE. HEAD is not handled yet.)
 122   # $2 = remote bucket.
 123   # $3 = remote name
 124   # $4 = local name.
 125   local bucket remote date sig md5 arg inout headers
 126   # header handling is kinda fugly, but it works.
 127   bucket="${2:+/${2}}/" # slashify the bucket
 128   remote="$(urlenc "${3}")" # if you don't, strange things may happen.
 129   stdopts="--connect-timeout 10 --fail --silent"
 130   [[ $CURL_S3_DEBUG == true ]] && stdopts="${stdopts} --show-error --fail"
 131   case "${1}" in
 132    GET) arg="-o" inout="${4:--}" # stdout if no $4
 133         ;;
 134    PUT) [[ ${2} ]] || die "PUT can has bucket?"
 135         if [[ ! ${3} ]]; then
 136           arg="-X PUT"
 137           headers[${#headers[@]}]="Content-Length: 0"
 138         elif [[ -f ${4} ]]; then
 139           md5="$(openssl dgst -md5 -binary "${4}"|openssl base64 -e -a)"
 140           arg="-T" inout="${4}"
 141           headers[${#headers[@]}]="Expect: 100-continue"
 142         else
 143           die "Cannot write non-existing file ${4}"
 144         fi
 145         ;;
 146    DELETE) arg="-X DELETE"
 147            ;;
 148    HEAD) arg="-I" ;;
 149    *) die "Unknown verb ${1}.  It probably would not have worked anyways." ;;
 150   esac
 151   date="$(TZ=UTC date '+%a, %e %b %Y %H:%M:%S %z')"
 152   sig=$(s3_signature_string ${1} "${date}" "${bucket}" "${remote}" "${md5}")
 153
 154   headers[${#headers[@]}]="Authorization: AWS ${S3_ACCESS_KEY_ID}:${sig}"
 155   headers[${#headers[@]}]="Date: ${date}"
 156   [[ ${md5} ]] && headers[${#headers[@]}]="Content-MD5: ${md5}"
 157     curl ${arg} "${inout}" ${stdopts} -K <(curl_headers "${headers[@]}") \
 158        "http://s3.amazonaws.com${bucket}${remote}"
 159   return $?
 160 }
 161
 162 s3_put() {
 163   # $1 = remote bucket to put it into
 164   # $2 = remote name to put
 165   # $3 = file to put.  This must be present if $2 is.
 166   s3_curl PUT "${1}" "${2}" "${3:-${2}}"
 167   return $?
 168 }
 169
 170 s3_get() {
 171   # $1 = bucket to get file from
 172   # $2 = remote file to get
 173   # $3 = local file to get into. Will be overwritten if it exists.
 174   #      If this contains a path, that path must exist before calling this.
 175   s3_curl GET "${1}" "${2}" "${3:-${2}}"
 176   return $?
 177 }
 178
 179 s3_test() {
 180   # same args as s3_get, but uses the HEAD verb instead of the GET verb.
 181   s3_curl HEAD "${1}" "${2}" >/dev/null
 182   return $?
 183 }
 184
 185 # Hideously ugly, but it works well enough.
 186 s3_buckets() {
 187   s3_get |grep -o '<Name>[^>]*</Name>' |sed 's/<[^>]*>//g' |xmldec
 188   return $?
 189 }
 190
 191 # this will only return the first thousand entries, alas
 192 # Mabye some kind soul can fix this without writing an XML parser in bash?
 193 # Also need to add xml entity handling.
 194 s3_list() {
 195   # $1 = bucket to list
 196   [ "x${1}" == "x" ] && return 1
 197   s3_get "${1}" |grep -o '<Key>[^>]*</Key>' |sed 's/<[^>]*>//g'| xmldec
 198   return $?
 199 }
 200
 201 s3_delete() {
 202   # $1 = bucket to delete from
 203   # $2 = item to delete
 204   s3_curl DELETE "${1}" "${2}"
 205   return $?
 206 }
 207
 208 # because this uses s3_list, it suffers from the same flaws.
 209 s3_rmrf() {
 210   # $1 = bucket to delete everything from
 211   s3_list "${1}" | while read f; do
 212     s3_delete "${1}" "${f}";
 213   done
 214 }
 215
 216 check_deps
 217 case $1 in
 218   put) shift; s3_put "$@" ;;
 219   get) shift; s3_get "$@" ;;
 220   rm) shift; s3_delete "$@" ;;
 221   ls) shift; s3_list "$@" ;;
 222   test) shift; s3_test "$@" ;;
 223   buckets) s3_buckets ;;
 224   rmrf) shift; s3_rmrf "$@" ;;
 225   *) die "Unknown command ${1}."
 226     ;;
 227 esac
 228