RSA signature verification and SHA-1/256/512 reference implementation for verified boot.

src/platform/vboot_reference/crypto/genpadding.sh

+#!/bin/bash
+
+# Copyright (c) 2010 The Chromium OS Authors. All rights reserved.
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+
+# Script to generate padding.c containing PKCS 1.5 padding byte arrays for
+# various combinations of RSA key lengths and message digest algorithms. 
+
+Pad_Preamble="0x00,0x01"
+
+SHA1_Suffix="0x30,0x21,0x30,0x09,0x06,0x05,0x2b,0x0e,0x03,0x02,0x1a,0x05"\
+",0x00,0x04,0x14"
+SHA256_Suffix="0x30,0x31,0x30,0x0d,0x06,0x09,0x60,0x86,0x48,0x01,0x65,0x03"\
+",0x04,0x02,0x01,0x05,0x00,0x04,0x20"
+SHA512_Suffix="0x30,0x51,0x30,0x0d,0x06,0x09,0x60,0x86,0x48,0x01,0x65,0x03"\
+",0x04,0x02,0x03,0x05,0x00,0x04,0x40"
+
+RSA1024_Len=128
+RSA2048_Len=256
+RSA4096_Len=512
+RSA8192_Len=1024
+
+SHA1_T_Len=35
+SHA256_T_Len=51
+SHA512_T_Len=83
+
+HashAlgos=( SHA1 SHA256 SHA512 )
+RSAAlgos=( RSA1024 RSA2048 RSA4096 RSA8192 ) 
+
+function genFFOctets {
+  count=$1
+  while [ $count -gt 0 ]; do
+    echo -n "0xff,"
+    let count=count-1
+  done
+}
+
+
+cat <<EOF
+/*
+ * DO NOT MODIFY THIS FILE DIRECTLY.
+ *
+ * This file is automatically generated by genpadding.sh and contains padding
+ * arrays corresponding to various combinations of algorithms for RSA signatures.
+ */
+
+EOF
+
+
+echo '#include "rsa.h"'
+echo '#include "sha.h"'
+echo
+echo
+cat <<EOF 
+/*
+ * PKCS 1.5 padding (from the RSA PKCS#1 v2.1 standard)
+ *
+ * Depending on the RSA key size and hash function, the padding is calculated
+ * as follows:
+ *
+ * 0x00 || 0x01 || PS || 0x00 || T
+ *
+ * T: DER Encoded DigestInfo value which depends on the hash function used.
+ *
+ * SHA-1:   (0x)30 21 30 09 06 05 2b 0e 03 02 1a 05 00 04 14 || H.
+ * SHA-256: (0x)30 31 30 0d 06 09 60 86 48 01 65 03 04 02 01 05 00 04 20 || H.
+ * SHA-512: (0x)30 51 30 0d 06 09 60 86 48 01 65 03 04 02 03 05 00 04 40 || H.
+ *
+ * Length(T) = 35 octets for SHA-1
+ * Length(T) = 51 octets for SHA-256
+ * Length(T) = 83 octets for SHA-512
+ *
+ * PS: octet string consisting of {Length(RSA Key) - Length(T) - 3} 0xFF
+ *
+ */
+EOF
+echo
+echo
+
+
+# Generate padding arrays.
+algorithmcounter=0
+
+for rsaalgo in ${RSAAlgos[@]}
+do
+  for hashalgo in ${HashAlgos[@]}
+  do
+    echo "/* Algorithm Type $algorithmcounter */"
+    let algorithmcounter=algorithmcounter+1
+    eval rsalen=${rsaalgo}_Len
+    eval hashlen=${hashalgo}_T_Len
+    let nums=rsalen-hashlen-3 
+    echo "const uint8_t padding${rsaalgo}_${hashalgo}[${rsaalgo}NUMBYTES - ${hashalgo}_DIGEST_SIZE] = {"
+    echo -n $Pad_Preamble,
+    genFFOctets $nums
+    echo -n "0x00,"
+    eval suffix=\$${hashalgo}_Suffix
+    echo $suffix
+    echo "};"
+    echo
+  done
+done
+
+echo "const int kNumAlgorithms = $algorithmcounter;";
+echo "#define NUMALGORITHMS $algorithmcounter"
+echo
+
+# Generate algorithm signature length map
+echo "const int siglen_map[NUMALGORITHMS] = {"
+for rsaalgo in ${RSAAlgos[@]}
+do
+  for hashalgo in ${HashAlgos[@]}
+  do
+    echo ${rsaalgo}NUMWORDS,
+  done
+done
+echo "};"
+echo
+
+# Generate algorithm padding array map
+echo "const uint8_t* padding_map[NUMALGORITHMS] = {"
+for rsaalgo in ${RSAAlgos[@]}
+do
+  for hashalgo in ${HashAlgos[@]}
+  do
+     echo padding${rsaalgo}_${hashalgo},
+  done
+done
+echo "};"
+echo
+
+# Generate algorithm padding size map
+echo "const int padding_size_map[NUMALGORITHMS] = {"
+for rsaalgo in ${RSAAlgos[@]}
+do
+  for hashalgo in ${HashAlgos[@]}
+  do
+    echo ${rsaalgo}NUMBYTES - ${hashalgo}_DIGEST_SIZE,
+  done
+done
+echo "};"
+echo
+
+# Generate algorithm message digest's input block size.
+echo "const int hash_blocksize_map[NUMALGORITHMS] = {"
+for rsaalgo in ${RSAAlgos[@]}
+do
+  for hashalgo in ${HashAlgos[@]}
+  do
+    echo ${hashalgo}_BLOCK_SIZE,
+  done
+done
+echo "};"
+echo
+
+# Generate algorithm description strings.
+echo "const char* algo_strings[NUMALGORITHMS] = {"
+for rsaalgo in ${RSAAlgos[@]}
+do
+  for hashalgo in ${HashAlgos[@]}
+  do
+    echo \"${rsaalgo} ${hashalgo}\",
+  done
+done
+echo "};"
+echo
+
+#echo "#endif  /* VBOOT_REFERENCE_PADDING_H_ */"