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-rw-r--r--src/eyetil.cc29
-rw-r--r--src/eyetil.h3
2 files changed, 31 insertions, 1 deletions
diff --git a/src/eyetil.cc b/src/eyetil.cc
index 2fbd687..fe816a6 100644
--- a/src/eyetil.cc
+++ b/src/eyetil.cc
@@ -1,35 +1,36 @@
#include <stdlib.h>
#include <sys/stat.h>
#include <syslog.h>
#include <iostream>
#include <cassert>
#include <stdexcept>
+#include <algorithm>
+#include <numeric>
#include <openssl/md5.h>
#include "eyetil.h"
binary_t& binary_t::from_hex(const std::string& h) {
- /* TODO: algorithmize */
std::string::size_type hs = h.length();
if(hs&1)
throw std::runtime_error("odd number of characters in hexadecimal number");
int rvs = hs>>1;
resize(rvs);
const unsigned char *hp = (const unsigned char*)h.data();
iterator oi=begin();
char t[3] = { 0,0,0 };
for(int i=0;i<rvs;++i) {
t[0]=*(hp++); t[1]=*(hp++);
*(oi++) = strtol(t,0,16);
}
return *this;
}
binary_t& binary_t::from_data(const void *d,size_t s) {
resize(s);
std::copy((const unsigned char*)d,(const unsigned char *)d+s,
begin() );
return *this;
}
std::string binary_t::hex() const {
std::string rv;
@@ -96,24 +97,50 @@ tarchive_t::tarchive_t(void *p,size_t s) : a(archive_read_new()), e(0) {
if(archive_read_open_memory(a,p,s)) {
archive_read_finish(a);
throw std::runtime_error("failed to archive_read_open_memory()");
}
}
tarchive_t::~tarchive_t() {
assert(a);
archive_read_finish(a);
}
bool tarchive_t::read_next_header() {
assert(a);
return archive_read_next_header(a,&e)==ARCHIVE_OK;
}
std::string tarchive_t::entry_pathname() {
assert(a); assert(e);
return archive_entry_pathname(e);
}
bool tarchive_t::read_data_into_fd(int fd) {
assert(a);
return archive_read_data_into_fd(a,fd)==ARCHIVE_OK;
}
+
+#pragma pack(1)
+struct block512_t {
+ enum { words = 512 / sizeof(uint16_t) };
+ uint16_t data[words];
+
+ static uint16_t tcpcksum(block512_t& data) {
+ uint32_t sum = std::accumulate(data.data,data.data+words,0);
+ while(uint32_t hw = sum>>16) sum = (sum&0xffff)+hw;
+ return ~sum;
+ }
+
+};
+#pragma pack()
+
+binary_t integrity_digest(const void *ptr,size_t size,const std::string& ukey) {
+ binary_t key; key.from_hex(ukey);
+ std::vector<uint16_t> blksums; blksums.reserve(size/sizeof(block512_t));
+ block512_t *db = (block512_t*)ptr,
+ *de = db + size/sizeof(block512_t);
+ std::transform( db, de, std::back_inserter(blksums), block512_t::tcpcksum );
+ binary_t subject;
+ subject.from_data((void*)&(blksums.front()),blksums.size()*sizeof(uint16_t));
+ std::copy( key.begin(), key.end(), std::back_inserter(subject) );
+ return subject.md5();
+}
diff --git a/src/eyetil.h b/src/eyetil.h
index 195d24f..378f703 100644
--- a/src/eyetil.h
+++ b/src/eyetil.h
@@ -24,25 +24,28 @@ class tmpdir_t {
public:
std::string dir;
tmpdir_t(const std::string& dt);
~tmpdir_t();
std::string get_file(const std::string& f);
};
class tarchive_t {
public:
struct archive *a;
struct archive_entry *e;
tarchive_t(void *p,size_t s);
~tarchive_t();
bool read_next_header();
std::string entry_pathname();
bool read_data_into_fd(int fd);
};
+binary_t integrity_digest(const void *ptr,size_t size,
+ const std::string& ukey);
+
#endif /* __EYETIL_H */