diff options
Diffstat (limited to 'src/Common/TLVParser.cpp')
-rw-r--r-- | src/Common/TLVParser.cpp | 187 |
1 files changed, 187 insertions, 0 deletions
diff --git a/src/Common/TLVParser.cpp b/src/Common/TLVParser.cpp new file mode 100644 index 00000000..5ddf37e5 --- /dev/null +++ b/src/Common/TLVParser.cpp @@ -0,0 +1,187 @@ +#include "TLVParser.h" +#include <string.h> + +using namespace std; + +namespace VeraCrypt +{ + /* TLV node structure creation */ + shared_ptr<TLVNode> TLVParser::TLV_CreateNode() + { + shared_ptr<TLVNode> node = shared_ptr<TLVNode>(new TLVNode()); + return node; + } + + /* Check if the bit is correct */ + uint16 TLVParser::CheckBit(uint8 value, int bit) + { + unsigned char bitvalue[8] = {0x01, 0x02, 0x04, 0x08, 0x10, 0x20, 0x40, 0x80}; + + if ((bit >= 1) && (bit <= 8)) + { + if (value & bitvalue[bit-1]) + { + return (1); + } + else + { + return (0); + } + } + else + { + throw TLVException("FILE:"+string(__FILE__)+"LINE: "+to_string(static_cast<long long>((__LINE__)))+" fonction parameter incorrect! bit=["+to_string(static_cast<long long>(bit))); + //return(2); + } + } + + /* Parsing one TLV node */ + shared_ptr<TLVNode> TLVParser::TLV_Parse_One(uint8* buf, size_t size) + { + size_t index = 0; + size_t i = 0; + uint8 tag1, tag2, tagsize; + uint8 len, lensize; + shared_ptr<vector<uint8>> value = make_shared<vector<uint8>>(); + shared_ptr<TLVNode> node = TLV_CreateNode(); + + tag1 = tag2 = 0; + tagsize = 1; + tag1 = buf[index++]; + if ((tag1 & 0x1f) == 0x1f) + { + tagsize++; + tag2 = buf[index++]; + //tag2 b8 must be 0! + } + if (tagsize == 1) + { + node->Tag = tag1; + } + else + { + node->Tag = (tag1 << 8) + tag2; + } + node->TagSize = tagsize; + + //SubFlag + node->SubFlag = CheckBit(tag1,6); + + //L zone + len = 0; + lensize = 1; + len = buf[index++]; + if (CheckBit(len,8) == 0) + { + node->Length = len; + } + else + { + lensize = len & 0x7f; + len = 0; + for (i = 0; i < lensize; i++) + { + len += (uint16)buf[index++] << (i*8); + } + lensize++; + } + node->Length = len; + node->LengthSize = lensize; + + //V zone + value->resize(len); + memcpy(value->data(), buf + index, len); + node->Value = value; + index += len; + + if (index < size) + { + node->MoreFlag = 1; + } + else if(index == size) + { + node->MoreFlag = 0; + } + else + { + throw TLVException("Parse Error! index="+to_string(static_cast<long long>(index))+"size="+to_string(static_cast<long long>(size))); + } + + return node; + } + + /* Parsing all sub-nodes (in width not in depth) of a given parent node */ + int TLVParser::TLV_Parse_SubNodes(shared_ptr<TLVNode> parent) + { + uint16 sublen = 0; + size_t i; + + //No sub-nodes + if (parent->SubFlag == 0) + return 0; + + for (i = 0; i < parent->Subs->size(); i++) + { + sublen += (parent->Subs->at(i)->TagSize + parent->Subs->at(i)->Length + parent->Subs->at(i)->LengthSize); + } + + if (sublen < parent->Value->size()) + { + shared_ptr<TLVNode> subnode = TLV_Parse_One(parent->Value->data() + sublen, parent->Value->size() - sublen); + parent->Subs->push_back(subnode); + return subnode->MoreFlag; + } + else + { + return 0; + } + } + + /* Recursive function to parse all nodes starting from a root parent node */ + void TLVParser::TLV_Parse_Sub(shared_ptr<TLVNode> parent) + { + size_t i; + if (parent->SubFlag != 0) + { + // Parse all sub nodes. + while (TLV_Parse_SubNodes(parent) != 0); + + for (i = 0; i < parent->Subs->size(); i++) + { + if (parent->Subs->at(i)->SubFlag != 0) + { + TLV_Parse_Sub(parent->Subs->at(i)); + } + } + } + } + + /* Parsing TLV from a buffer and constructing TLV structure */ + shared_ptr<TLVNode> TLVParser::TLV_Parse(uint8* buf, size_t size) + { + shared_ptr<TLVNode> node = TLV_Parse_One(buf, size); + TLV_Parse_Sub(node); + + return node; + } + + /* Finding a TLV node with a particular tag */ + shared_ptr<TLVNode> TLVParser::TLV_Find(shared_ptr<TLVNode> node, uint16 tag) + { + size_t i = 0; + shared_ptr<TLVNode> tmpnode; + if (node->Tag == tag) + { + return node; + } + for (i = 0; i < node->Subs->size(); i++) + { + tmpnode = TLV_Find(node->Subs->at(i),tag); + if (tmpnode) + { + return tmpnode; + } + } + return shared_ptr<TLVNode>(); + } +} |