209
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1 /* LibTomCrypt, modular cryptographic library -- Tom St Denis |
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2 * |
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3 * LibTomCrypt is a library that provides various cryptographic |
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4 * algorithms in a highly modular and flexible manner. |
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5 * |
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6 * The library is free for all purposes without any express |
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7 * guarantee it works. |
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8 * |
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9 * Tom St Denis, [email protected], http://libtomcrypt.org |
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10 */ |
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11 #include "tomcrypt.h" |
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12 #include <stdarg.h> |
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13 |
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14 |
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15 /** |
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16 @file der_length_sequence.c |
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17 ASN.1 DER, length a SEQUENCE, Tom St Denis |
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18 */ |
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19 |
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20 #ifdef LTC_DER |
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21 |
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22 /** |
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23 Get the length of a DER sequence |
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24 @param list The sequences of items in the SEQUENCE |
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25 @param inlen The number of items |
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26 @param outlen [out] The length required in octets to store it |
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27 @return CRYPT_OK on success |
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28 */ |
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29 int der_length_sequence(ltc_asn1_list *list, unsigned long inlen, |
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30 unsigned long *outlen) |
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31 { |
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32 int err, type; |
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33 unsigned long size, x, y, z, i; |
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34 void *data; |
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35 |
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36 LTC_ARGCHK(list != NULL); |
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37 LTC_ARGCHK(outlen != NULL); |
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38 |
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39 /* get size of output that will be required */ |
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40 y = 0; |
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41 for (i = 0; i < inlen; i++) { |
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42 type = list[i].type; |
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43 size = list[i].size; |
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44 data = list[i].data; |
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45 |
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46 if (type == LTC_ASN1_EOL) { |
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47 break; |
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48 } |
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49 |
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50 switch (type) { |
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51 case LTC_ASN1_INTEGER: |
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52 if ((err = der_length_integer(data, &x)) != CRYPT_OK) { |
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53 goto LBL_ERR; |
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54 } |
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55 y += x; |
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56 break; |
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57 |
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58 case LTC_ASN1_SHORT_INTEGER: |
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59 if ((err = der_length_short_integer(*((unsigned long *)data), &x)) != CRYPT_OK) { |
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60 goto LBL_ERR; |
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61 } |
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62 y += x; |
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63 break; |
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64 |
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65 case LTC_ASN1_BIT_STRING: |
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66 if ((err = der_length_bit_string(size, &x)) != CRYPT_OK) { |
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67 goto LBL_ERR; |
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68 } |
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69 y += x; |
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70 break; |
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71 |
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72 case LTC_ASN1_OCTET_STRING: |
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73 if ((err = der_length_octet_string(size, &x)) != CRYPT_OK) { |
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74 goto LBL_ERR; |
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75 } |
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76 y += x; |
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77 break; |
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78 |
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79 case LTC_ASN1_NULL: |
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80 y += 2; |
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81 break; |
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82 |
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83 case LTC_ASN1_OBJECT_IDENTIFIER: |
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84 if ((err = der_length_object_identifier(data, size, &x)) != CRYPT_OK) { |
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85 goto LBL_ERR; |
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86 } |
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87 y += x; |
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88 break; |
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89 |
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90 case LTC_ASN1_IA5_STRING: |
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91 if ((err = der_length_ia5_string(data, size, &x)) != CRYPT_OK) { |
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92 goto LBL_ERR; |
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93 } |
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94 y += x; |
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95 break; |
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96 |
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97 case LTC_ASN1_PRINTABLE_STRING: |
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98 if ((err = der_length_printable_string(data, size, &x)) != CRYPT_OK) { |
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99 goto LBL_ERR; |
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100 } |
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101 y += x; |
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102 break; |
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103 |
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104 case LTC_ASN1_SEQUENCE: |
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105 if ((err = der_length_sequence(data, size, &x)) != CRYPT_OK) { |
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106 goto LBL_ERR; |
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107 } |
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108 y += x; |
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109 break; |
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110 |
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111 |
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112 default: |
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113 err = CRYPT_INVALID_ARG; |
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114 goto LBL_ERR; |
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115 } |
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116 } |
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117 |
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118 /* calc header size */ |
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119 z = y; |
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120 if (y < 128) { |
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121 y += 2; |
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122 } else if (y < 256) { |
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123 /* 0x30 0x81 LL */ |
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124 y += 3; |
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125 } else if (y < 65536UL) { |
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126 /* 0x30 0x82 LL LL */ |
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127 y += 4; |
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128 } else if (y < 16777216UL) { |
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129 /* 0x30 0x83 LL LL LL */ |
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130 y += 5; |
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131 } else { |
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132 err = CRYPT_INVALID_ARG; |
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133 goto LBL_ERR; |
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134 } |
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135 |
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136 /* store size */ |
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137 *outlen = y; |
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138 err = CRYPT_OK; |
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139 |
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140 LBL_ERR: |
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141 return err; |
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142 } |
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143 |
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144 #endif |