view libtomcrypt/src/pk/asn1/der/teletex_string/der_length_teletex_string.c @ 1928:333688ec53d0

Handle ecdsa-sk flags, reject no-touch For the time being Dropbear will only allow SK auth with default parameters, user-presence needs to be set. In future handling of authorized_keys option "no-touch-required" can be added. This code would also be refactored to share between ecdsa and ed25519 once I get hardware/emulation to test ed25519.
author Matt Johnston <matt@ucc.asn.au>
date Wed, 30 Mar 2022 21:06:15 +0800
parents 6dba84798cd5
children
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/* LibTomCrypt, modular cryptographic library -- Tom St Denis
 *
 * LibTomCrypt is a library that provides various cryptographic
 * algorithms in a highly modular and flexible manner.
 *
 * The library is free for all purposes without any express
 * guarantee it works.
 */
#include "tomcrypt.h"

/**
  @file der_length_teletex_string.c
  ASN.1 DER, get length of teletex STRING
*/

#ifdef LTC_DER

static const struct {
   int code, value;
} teletex_table[] = {
{ '\0',  0 },
{ '\a',  7 },
{ '\b',  8 },
{ '\t',  9 },
{ '\n', 10 },
{ '\v', 11 },
{ '\f', 12 },
{ '\r', 13 },
{ ' ',  32 },
{ '!',  33 },
{ '"',  34 },
{ '%',  37 },
{ '&',  38 },
{ '\'', 39 },
{ '(',  40 },
{ ')',  41 },
{ '+',  43 },
{ ',',  44 },
{ '-',  45 },
{ '.',  46 },
{ '/',  47 },
{ '0',  48 },
{ '1',  49 },
{ '2',  50 },
{ '3',  51 },
{ '4',  52 },
{ '5',  53 },
{ '6',  54 },
{ '7',  55 },
{ '8',  56 },
{ '9',  57 },
{ ':',  58 },
{ ';',  59 },
{ '<',  60 },
{ '=',  61 },
{ '>',  62 },
{ '?',  63 },
{ '@',  64 },
{ 'A',  65 },
{ 'B',  66 },
{ 'C',  67 },
{ 'D',  68 },
{ 'E',  69 },
{ 'F',  70 },
{ 'G',  71 },
{ 'H',  72 },
{ 'I',  73 },
{ 'J',  74 },
{ 'K',  75 },
{ 'L',  76 },
{ 'M',  77 },
{ 'N',  78 },
{ 'O',  79 },
{ 'P',  80 },
{ 'Q',  81 },
{ 'R',  82 },
{ 'S',  83 },
{ 'T',  84 },
{ 'U',  85 },
{ 'V',  86 },
{ 'W',  87 },
{ 'X',  88 },
{ 'Y',  89 },
{ 'Z',  90 },
{ '[',  91 },
{ ']',  93 },
{ '_',  95 },
{ 'a',  97 },
{ 'b',  98 },
{ 'c',  99 },
{ 'd',  100 },
{ 'e',  101 },
{ 'f',  102 },
{ 'g',  103 },
{ 'h',  104 },
{ 'i',  105 },
{ 'j',  106 },
{ 'k',  107 },
{ 'l',  108 },
{ 'm',  109 },
{ 'n',  110 },
{ 'o',  111 },
{ 'p',  112 },
{ 'q',  113 },
{ 'r',  114 },
{ 's',  115 },
{ 't',  116 },
{ 'u',  117 },
{ 'v',  118 },
{ 'w',  119 },
{ 'x',  120 },
{ 'y',  121 },
{ 'z',  122 },
{ '|',  124 },
{ ' ',  160 },
{ 0xa1, 161 },
{ 0xa2, 162 },
{ 0xa3, 163 },
{ '$',  164 },
{ 0xa5, 165 },
{ '#',  166 },
{ 0xa7, 167 },
{ 0xa4, 168 },
{ 0xab, 171 },
{ 0xb0, 176 },
{ 0xb1, 177 },
{ 0xb2, 178 },
{ 0xb3, 179 },
{ 0xd7, 180 },
{ 0xb5, 181 },
{ 0xb6, 182 },
{ 0xb7, 183 },
{ 0xf7, 184 },
{ 0xbb, 187 },
{ 0xbc, 188 },
{ 0xbd, 189 },
{ 0xbe, 190 },
{ 0xbf, 191 },
};

int der_teletex_char_encode(int c)
{
   int x;
   for (x = 0; x < (int)(sizeof(teletex_table)/sizeof(teletex_table[0])); x++) {
       if (teletex_table[x].code == c) {
          return teletex_table[x].value;
       }
   }
   return -1;
}

int der_teletex_value_decode(int v)
{
   int x;
   for (x = 0; x < (int)(sizeof(teletex_table)/sizeof(teletex_table[0])); x++) {
       if (teletex_table[x].value == v) {
          return teletex_table[x].code;
       }
   }
   return -1;
}

/**
  Gets length of DER encoding of teletex STRING
  @param octets   The values you want to encode
  @param noctets  The number of octets in the string to encode
  @param outlen   [out] The length of the DER encoding for the given string
  @return CRYPT_OK if successful
*/
int der_length_teletex_string(const unsigned char *octets, unsigned long noctets, unsigned long *outlen)
{
   unsigned long x;

   LTC_ARGCHK(outlen != NULL);
   LTC_ARGCHK(octets != NULL);

   /* scan string for validity */
   for (x = 0; x < noctets; x++) {
       if (der_teletex_char_encode(octets[x]) == -1) {
          return CRYPT_INVALID_ARG;
       }
   }

   if (noctets < 128) {
      /* 16 LL DD DD DD ... */
      *outlen = 2 + noctets;
   } else if (noctets < 256) {
      /* 16 81 LL DD DD DD ... */
      *outlen = 3 + noctets;
   } else if (noctets < 65536UL) {
      /* 16 82 LL LL DD DD DD ... */
      *outlen = 4 + noctets;
   } else if (noctets < 16777216UL) {
      /* 16 83 LL LL LL DD DD DD ... */
      *outlen = 5 + noctets;
   } else {
      return CRYPT_INVALID_ARG;
   }

   return CRYPT_OK;
}

#endif


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