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_decode_sequence.c |
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17 ASN.1 DER, decode 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 Decode a SEQUENCE |
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24 @param in The DER encoded input |
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25 @param inlen The size of the input |
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26 @param list The list of items to decode |
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27 @param outlen The number of items in the list |
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28 @return CRYPT_OK on success |
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29 */ |
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30 int der_decode_sequence(const unsigned char *in, unsigned long inlen, |
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31 ltc_asn1_list *list, unsigned long outlen) |
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32 { |
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33 int err, type; |
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34 unsigned long size, x, y, z, i, blksize; |
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35 void *data; |
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36 |
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37 LTC_ARGCHK(in != NULL); |
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38 LTC_ARGCHK(list != NULL); |
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39 |
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40 /* get blk size */ |
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41 if (inlen < 2) { |
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42 return CRYPT_INVALID_PACKET; |
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43 } |
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44 |
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45 /* sequence type? */ |
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46 x = 0; |
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47 if (in[x++] != 0x30) { |
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48 return CRYPT_INVALID_PACKET; |
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49 } |
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50 |
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51 if (in[x] < 128) { |
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52 blksize = in[x++]; |
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53 } else if (in[x] & 0x80) { |
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54 if (in[x] < 0x81 || in[x] > 0x83) { |
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55 return CRYPT_INVALID_PACKET; |
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56 } |
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57 y = in[x++] & 0x7F; |
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58 |
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59 /* would reading the len bytes overrun? */ |
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60 if (x + y > inlen) { |
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61 return CRYPT_INVALID_PACKET; |
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62 } |
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63 |
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64 /* read len */ |
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65 blksize = 0; |
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66 while (y--) { |
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67 blksize = (blksize << 8) | (unsigned long)in[x++]; |
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68 } |
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69 } |
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70 |
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71 /* would this blksize overflow? */ |
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72 if (x + blksize > inlen) { |
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73 return CRYPT_INVALID_PACKET; |
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74 } |
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75 |
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76 /* ok read data */ |
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77 inlen = blksize; |
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78 for (i = 0; i < outlen; i++) { |
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79 type = list[i].type; |
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80 size = list[i].size; |
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81 data = list[i].data; |
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82 |
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83 if (type == LTC_ASN1_EOL) { |
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84 break; |
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85 } |
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86 |
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87 switch (type) { |
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88 case LTC_ASN1_INTEGER: |
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89 z = inlen; |
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90 if ((err = der_decode_integer(in + x, z, data)) != CRYPT_OK) { |
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91 goto LBL_ERR; |
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92 } |
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93 if ((err = der_length_integer(data, &z)) != CRYPT_OK) { |
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94 goto LBL_ERR; |
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95 } |
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96 x += z; |
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97 inlen -= z; |
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98 break; |
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99 |
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100 |
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101 case LTC_ASN1_SHORT_INTEGER: |
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102 z = inlen; |
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103 if ((err = der_decode_short_integer(in + x, z, data)) != CRYPT_OK) { |
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104 goto LBL_ERR; |
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105 } |
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106 if ((err = der_length_short_integer(size, &z)) != CRYPT_OK) { |
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107 goto LBL_ERR; |
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108 } |
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109 x += z; |
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110 inlen -= z; |
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111 break; |
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112 |
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113 case LTC_ASN1_BIT_STRING: |
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114 z = inlen; |
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115 if ((err = der_decode_bit_string(in + x, z, data, &size)) != CRYPT_OK) { |
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116 goto LBL_ERR; |
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117 } |
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118 list[i].size = size; |
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119 if ((err = der_length_bit_string(size, &z)) != CRYPT_OK) { |
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120 goto LBL_ERR; |
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121 } |
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122 x += z; |
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123 inlen -= z; |
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124 break; |
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125 |
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126 case LTC_ASN1_OCTET_STRING: |
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127 z = inlen; |
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128 if ((err = der_decode_octet_string(in + x, z, data, &size)) != CRYPT_OK) { |
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129 goto LBL_ERR; |
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130 } |
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131 list[i].size = size; |
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132 if ((err = der_length_octet_string(size, &z)) != CRYPT_OK) { |
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133 goto LBL_ERR; |
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134 } |
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135 x += z; |
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136 inlen -= z; |
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137 break; |
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138 |
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139 case LTC_ASN1_NULL: |
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140 if (inlen < 2 || in[x] != 0x05 || in[x+1] != 0x00) { |
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141 err = CRYPT_INVALID_PACKET; |
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142 goto LBL_ERR; |
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143 } |
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144 x += 2; |
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145 inlen -= 2; |
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146 break; |
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147 |
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148 case LTC_ASN1_OBJECT_IDENTIFIER: |
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149 z = inlen; |
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150 if ((err = der_decode_object_identifier(in + x, z, data, &size)) != CRYPT_OK) { |
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151 goto LBL_ERR; |
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152 } |
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153 list[i].size = size; |
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154 if ((err = der_length_object_identifier(data, size, &z)) != CRYPT_OK) { |
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155 goto LBL_ERR; |
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156 } |
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157 x += z; |
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158 inlen -= z; |
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159 break; |
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160 |
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161 case LTC_ASN1_IA5_STRING: |
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162 z = inlen; |
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163 if ((err = der_decode_ia5_string(in + x, z, data, &size)) != CRYPT_OK) { |
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164 goto LBL_ERR; |
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165 } |
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166 list[i].size = size; |
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167 if ((err = der_length_ia5_string(data, size, &z)) != CRYPT_OK) { |
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168 goto LBL_ERR; |
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169 } |
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170 x += z; |
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171 inlen -= z; |
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172 break; |
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173 |
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174 |
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175 case LTC_ASN1_PRINTABLE_STRING: |
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176 z = inlen; |
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177 if ((err = der_decode_printable_string(in + x, z, data, &size)) != CRYPT_OK) { |
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178 goto LBL_ERR; |
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179 } |
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180 list[i].size = size; |
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181 if ((err = der_length_printable_string(data, size, &z)) != CRYPT_OK) { |
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182 goto LBL_ERR; |
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183 } |
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184 x += z; |
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185 inlen -= z; |
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186 break; |
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187 |
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188 case LTC_ASN1_UTCTIME: |
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189 z = inlen; |
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190 if ((err = der_decode_utctime(in + x, &z, data)) != CRYPT_OK) { |
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191 goto LBL_ERR; |
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192 } |
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193 x += z; |
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194 inlen -= z; |
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195 break; |
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196 |
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197 case LTC_ASN1_SEQUENCE: |
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198 z = inlen; |
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199 if ((err = der_decode_sequence(in + x, z, data, size)) != CRYPT_OK) { |
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200 goto LBL_ERR; |
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201 } |
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202 if ((err = der_length_sequence(data, size, &z)) != CRYPT_OK) { |
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203 goto LBL_ERR; |
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204 } |
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205 x += z; |
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206 inlen -= z; |
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207 break; |
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208 |
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209 |
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210 case LTC_ASN1_CHOICE: |
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211 z = inlen; |
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212 if ((err = der_decode_choice(in + x, &z, data, size)) != CRYPT_OK) { |
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213 goto LBL_ERR; |
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214 } |
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215 x += z; |
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216 inlen -= z; |
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217 break; |
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218 |
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219 default: |
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220 err = CRYPT_INVALID_ARG; |
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221 goto LBL_ERR; |
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222 } |
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223 } |
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224 err = CRYPT_OK; |
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225 |
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226 LBL_ERR: |
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227 return err; |
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228 } |
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229 |
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230 #endif |
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231 |
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232 /* $Source: /cvs/libtom/libtomcrypt/src/pk/asn1/der/sequence/der_decode_sequence.c,v $ */ |
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233 /* $Revision: 1.8 $ */ |
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234 /* $Date: 2005/06/18 19:20:23 $ */ |