scripts/sign-file

   1 #!/bin/sh
   2 #
   3 # Sign a module file using the given key.
   4 #
   5 # Format: sign-file <key> <x509> <src-file> <dst-file>
   6 #
   7
   8 scripts=`dirname $0`
   9
  10 CONFIG_MODULE_SIG_SHA512=y
  11 if [ -r .config ]
  12 then
  13     . ./.config
  14 fi
  15
  16 key="$1"
  17 x509="$2"
  18 src="$3"
  19 dst="$4"
  20
  21 if [ ! -r "$key" ]
  22 then
  23     echo "Can't read private key" >&2
  24     exit 2
  25 fi
  26
  27 if [ ! -r "$x509" ]
  28 then
  29     echo "Can't read X.509 certificate" >&2
  30     exit 2
  31 fi
  32 if [ ! -r "$x509.signer" ]
  33 then
  34     echo "Can't read Signer name" >&2
  35     exit 2;
  36 fi
  37 if [ ! -r "$x509.keyid" ]
  38 then
  39     echo "Can't read Key identifier" >&2
  40     exit 2;
  41 fi
  42
  43 #
  44 # Signature parameters
  45 #
  46 algo=1          # Public-key crypto algorithm: RSA
  47 hash=           # Digest algorithm
  48 id_type=1       # Identifier type: X.509
  49
  50 #
  51 # Digest the data
  52 #
  53 dgst=
  54 if [ "$CONFIG_MODULE_SIG_SHA1" = "y" ]
  55 then
  56     prologue="0x30, 0x21, 0x30, 0x09, 0x06, 0x05, 0x2B, 0x0E, 0x03, 0x02, 0x1A, 0x05, 0x00, 0x04, 0x14"
  57     dgst=-sha1
  58     hash=2
  59 elif [ "$CONFIG_MODULE_SIG_SHA224" = "y" ]
  60 then
  61     prologue="0x30, 0x2d, 0x30, 0x0d, 0x06, 0x09, 0x60, 0x86, 0x48, 0x01, 0x65, 0x03, 0x04, 0x02, 0x04, 0x05, 0x00, 0x04, 0x1C"
  62     dgst=-sha224
  63     hash=7
  64 elif [ "$CONFIG_MODULE_SIG_SHA256" = "y" ]
  65 then
  66     prologue="0x30, 0x31, 0x30, 0x0d, 0x06, 0x09, 0x60, 0x86, 0x48, 0x01, 0x65, 0x03, 0x04, 0x02, 0x01, 0x05, 0x00, 0x04, 0x20"
  67     dgst=-sha256
  68     hash=4
  69 elif [ "$CONFIG_MODULE_SIG_SHA384" = "y" ]
  70 then
  71     prologue="0x30, 0x41, 0x30, 0x0d, 0x06, 0x09, 0x60, 0x86, 0x48, 0x01, 0x65, 0x03, 0x04, 0x02, 0x02, 0x05, 0x00, 0x04, 0x30"
  72     dgst=-sha384
  73     hash=5
  74 elif [ "$CONFIG_MODULE_SIG_SHA512" = "y" ]
  75 then
  76     prologue="0x30, 0x51, 0x30, 0x0d, 0x06, 0x09, 0x60, 0x86, 0x48, 0x01, 0x65, 0x03, 0x04, 0x02, 0x03, 0x05, 0x00, 0x04, 0x40"
  77     dgst=-sha512
  78     hash=6
  79 else
  80     echo "$0: Can't determine hash algorithm" >&2
  81     exit 2
  82 fi
  83
  84 (
  85 perl -e "binmode STDOUT; print pack(\"C*\", $prologue)" || exit $?
  86 openssl dgst $dgst -binary $src || exit $?
  87 ) >$src.dig || exit $?
  88
  89 #
  90 # Generate the binary signature, which will be just the integer that comprises
  91 # the signature with no metadata attached.
  92 #
  93 openssl rsautl -sign -inkey $key -keyform PEM -in $src.dig -out $src.sig || exit $?
  94 signerlen=`stat -c %s $x509.signer`
  95 keyidlen=`stat -c %s $x509.keyid`
  96 siglen=`stat -c %s $src.sig`
  97
  98 #
  99 # Build the signed binary
 100 #
 101 (
 102     cat $src || exit $?
 103     echo '~Module signature appended~' || exit $?
 104     cat $x509.signer $x509.keyid || exit $?
 105
 106     # Preface each signature integer with a 2-byte BE length
 107     perl -e "binmode STDOUT; print pack(\"n\", $siglen)" || exit $?
 108     cat $src.sig || exit $?
 109
 110     # Generate the information block
 111     perl -e "binmode STDOUT; print pack(\"CCCCCxxxN\", $algo, $hash, $id_type, $signerlen, $keyidlen, $siglen + 2)" || exit $?
 112 ) >$dst~ || exit $?
 113
 114 # Permit in-place signing
 115 mv $dst~ $dst || exit $?