Tech Blog of Edward

[libressl] Generate RSA key

admin / 1 June, 2018

In the latest version of libressl, RSA_generate_key is deprecated, RSA_generate_key_ex should be implemented instead. Implementation (updated) Source file (test.c)

#include <openssl/rsa.h>
#include <openssl/pem.h>

int main(){
	const int kBits = 2048;
	unsigned long e = RSA_F4;
	int keylen;
	char *pem_key;
	
	// BIGNUM PART
	BIGNUM* bignum = BN_new();
	if(BN_set_word(bignum, e))
		printf("[Debug] BIGNUM allocated!\n");
	else
		printf("[Debug] BIGNUM NOT allocated!\n");

	// RSA PART
	RSA *rsa = RSA_new();
	if(RSA_generate_key_ex(rsa, 2048, bignum, NULL))
		printf("[Debug] RSA allocated!\n");
	else
		printf("[Debug] RSA NOT allocated!\n");

	// BIO PART
	BIO *bio = BIO_new(BIO_s_mem());
	PEM_write_bio_RSAPrivateKey(bio, rsa, NULL, NULL, 0, NULL, NULL);

	keylen = BIO_pending(bio);
	pem_key = calloc(keylen+1, 1); /* Null-terminate */
	BIO_read(bio, pem_key, keylen);

	// OUTPUT
	printf("%s", pem_key);

	// FREE THE MEMORY
	BIO_free_all(bio);
	RSA_free(rsa);
	BN_free(bignum);
	free(pem_key);
	return 0;
}

#include <openssl/rsa.h>

#include <openssl/pem.h>

int main(){

const int kBits = 2048;

unsigned long e = RSA_F4;

int keylen;

char *pem_key;

// BIGNUM PART

BIGNUM* bignum = BN_new();

if(BN_set_word(bignum, e))

printf("[Debug] BIGNUM allocated!\n");

else

printf("[Debug] BIGNUM NOT allocated!\n");

// RSA PART

RSA *rsa = RSA_new();

if(RSA_generate_key_ex(rsa, 2048, bignum, NULL))

printf("[Debug] RSA allocated!\n");

else

printf("[Debug] RSA NOT allocated!\n");

// BIO PART

BIO *bio = BIO_new(BIO_s_mem());

PEM_write_bio_RSAPrivateKey(bio, rsa, NULL, NULL, 0, NULL, NULL);

keylen = BIO_pending(bio);

pem_key = calloc(keylen+1, 1); /* Null-terminate */

BIO_read(bio, pem_key, keylen);

// OUTPUT

printf("%s", pem_key);

// FREE THE MEMORY

BIO_free_all(bio);

RSA_free(rsa);

BN_free(bignum);

free(pem_key);

return 0;

}

To compile and run the program, the library libcrypto should be imported

gcc test.c -lcrypto && ./a.out

1	gcc test.c -lcrypto && ./a.out

Expected output

[Debug] BIGNUM allocated!
[Debug] RSA allocated!
-----BEGIN RSA PRIVATE KEY-----
MIIEpAIBAAKCAQEAw6QyusfybtOxUolVOgSqEEB2+Z673ivZohn2kWyw/W0jSxzR
drQuK+OXcQYMxft09LtYkqtnhf8cA/UoFhOg2edhfI21j7R+4WHadJeq+cFEBceY
x7+uiHh0ju/OX7vBoGg1BaiE6Hw/c6KI90HQpG4fEAIJ3qjAe4MAkBbbdmylN9mb
iSwQi5NgY9ves3gVl7ZSlwpFfq72gUPoQzQPF5cquYZohHbv4d8c0Jee+npi1pmM
eXZHUqLhkxR1DZpqDW2UI49y/DtDWzjeAnEGP22hEa7f53alFWpwAVvSs2iH7JqP
uN6+KI+0iVErH4pDAiF1H0SwV0W7YTQNzo147QIDAQABAoIBAQCTlSPnnrmVPQBB
APRXxfj8NYUKnOGfoXiVPfywi0uggVnkaaLhZt6FoTQ2wJeWKjB6BXG1grOfc2iQ
27kXnkry1gbGTKgv9brZDlYbKeaCbXaA3aa02DYzIJrc0K3freVMug91a0CHmGLN
OkkULIPV5nRsQP1tB+PbyGD+UR/Q3qatpWvmPYjDJwjVTg9iB24c5AqNDJlGbcFZ
OrtJC1ns2f/YpGZNooVyk/ULjCOgukYf3izmEVuxaDpZ86uGwAWiuwurZT0BjqAL
jIRNl6J4sk49OKiJx7VqnVSsPaHjiyPcWrgIhN+Zoy/nPqPmwkBmfjFqO62aAx09
Ba2NvLvBAoGBAOU56A8NYjtXARzdoXABNqIqYvcm61wt/XV+Tf2E9xOzbic6/uuK
gUHf18dqEH23FJFW9e1dkBWzWO9PdgCzGvmyec82WJRJMuFsgoHdAiKt3oca/OCN
2ZlgQqrWafNHfEIpVbqmyhizS2F5hnBcEw5NrN+APJYc7r91h20QJ1BFAoGBANp+
Eo6WcDlZJrZqolhTdZLt+Nr9/1/cEy0mkMYNMTD+tZEymEViDtm8wfqL20euWU2r
0WngNBs3pHEeaywa5B8y1p0n3koco5Cjkt6LDPAOg+6vymtK5/Uw7mY+P2EhJPTJ
5NuEKYDltnGu75z1/mcbDaHEXwZNw8LjHX0xd7SJAoGAYfO1s0Dv2hWatyAKDVen
ZfKg6aYq6vAIH/4CC7SW9Ec3afIu3q4IAANMLL2pIF9snZLAclcJ7AwAk/qrnS7r
9wmKPb6maW9CG8wHlMDBWdpcffVNXBOhiYX11xTan4fLlGYfaSw+rgFn09ZfWYIu
7mzI05Tzzt28M/pgDX3antUCgYEApR0c/PAnAs+id7wBz2nSsiRwKV5FPLXdMAOy
6FhT0kjKAV4QwG4n9te0Z5iFL5hMGGw9pxsthVv5QxrPttbjicgrczwLukoGOWnD
tbWzIz506U2jVI2Y2SwPHOjxkH8xpGNmNZWcn7H4u9SNczpa9KP3G0aA4QynYYGs
aU2WvrECgYAWVONkYjYUc1EChoEK/VK9QGUTQUrb+IDAzQF/GmwONmOnWz1SW4iF
OxkePdHnA/TPwLBp/78yUHwuJHnHawgOo9XR3aDz15h318kZtv2/BygHMVX8XZbS
vlI7wPlyxRvmMhxgBxqmqQQCRVvyRXLEirg91fqPkECCnx9mT/cPHw==
-----END RSA PRIVATE KEY-----

[Debug] BIGNUM allocated!

[Debug] RSA allocated!

-----BEGIN RSA PRIVATE KEY-----

MIIEpAIBAAKCAQEAw6QyusfybtOxUolVOgSqEEB2+Z673ivZohn2kWyw/W0jSxzR

drQuK+OXcQYMxft09LtYkqtnhf8cA/UoFhOg2edhfI21j7R+4WHadJeq+cFEBceY

x7+uiHh0ju/OX7vBoGg1BaiE6Hw/c6KI90HQpG4fEAIJ3qjAe4MAkBbbdmylN9mb

iSwQi5NgY9ves3gVl7ZSlwpFfq72gUPoQzQPF5cquYZohHbv4d8c0Jee+npi1pmM

eXZHUqLhkxR1DZpqDW2UI49y/DtDWzjeAnEGP22hEa7f53alFWpwAVvSs2iH7JqP

uN6+KI+0iVErH4pDAiF1H0SwV0W7YTQNzo147QIDAQABAoIBAQCTlSPnnrmVPQBB

APRXxfj8NYUKnOGfoXiVPfywi0uggVnkaaLhZt6FoTQ2wJeWKjB6BXG1grOfc2iQ

27kXnkry1gbGTKgv9brZDlYbKeaCbXaA3aa02DYzIJrc0K3freVMug91a0CHmGLN

OkkULIPV5nRsQP1tB+PbyGD+UR/Q3qatpWvmPYjDJwjVTg9iB24c5AqNDJlGbcFZ

OrtJC1ns2f/YpGZNooVyk/ULjCOgukYf3izmEVuxaDpZ86uGwAWiuwurZT0BjqAL

jIRNl6J4sk49OKiJx7VqnVSsPaHjiyPcWrgIhN+Zoy/nPqPmwkBmfjFqO62aAx09

Ba2NvLvBAoGBAOU56A8NYjtXARzdoXABNqIqYvcm61wt/XV+Tf2E9xOzbic6/uuK

gUHf18dqEH23FJFW9e1dkBWzWO9PdgCzGvmyec82WJRJMuFsgoHdAiKt3oca/OCN

2ZlgQqrWafNHfEIpVbqmyhizS2F5hnBcEw5NrN+APJYc7r91h20QJ1BFAoGBANp+

Eo6WcDlZJrZqolhTdZLt+Nr9/1/cEy0mkMYNMTD+tZEymEViDtm8wfqL20euWU2r

0WngNBs3pHEeaywa5B8y1p0n3koco5Cjkt6LDPAOg+6vymtK5/Uw7mY+P2EhJPTJ

5NuEKYDltnGu75z1/mcbDaHEXwZNw8LjHX0xd7SJAoGAYfO1s0Dv2hWatyAKDVen

ZfKg6aYq6vAIH/4CC7SW9Ec3afIu3q4IAANMLL2pIF9snZLAclcJ7AwAk/qrnS7r

9wmKPb6maW9CG8wHlMDBWdpcffVNXBOhiYX11xTan4fLlGYfaSw+rgFn09ZfWYIu

7mzI05Tzzt28M/pgDX3antUCgYEApR0c/PAnAs+id7wBz2nSsiRwKV5FPLXdMAOy

6FhT0kjKAV4QwG4n9te0Z5iFL5hMGGw9pxsthVv5QxrPttbjicgrczwLukoGOWnD

tbWzIz506U2jVI2Y2SwPHOjxkH8xpGNmNZWcn7H4u9SNczpa9KP3G0aA4QynYYGs

aU2WvrECgYAWVONkYjYUc1EChoEK/VK9QGUTQUrb+IDAzQF/GmwONmOnWz1SW4iF

OxkePdHnA/TPwLBp/78yUHwuJHnHawgOo9XR3aDz15h318kZtv2/BygHMVX8XZbS

vlI7wPlyxRvmMhxgBxqmqQQCRVvyRXLEirg91fqPkECCnx9mT/cPHw==

-----END RSA PRIVATE KEY-----

Implementation (deprecated) Source file (test.c)

#include <openssl/rsa.h>
#include <openssl/pem.h>

int main(){
	const int kBits = 1024;
	const int kExp = 3;

	int keylen;
	char *pem_key;

	RSA *rsa = RSA_generate_key(kBits, kExp, 0, 0);

	/* To get the C-string PEM form: */
	BIO *bio = BIO_new(BIO_s_mem());
	PEM_write_bio_RSAPrivateKey(bio, rsa, NULL, NULL, 0, NULL, NULL);

	keylen = BIO_pending(bio);
	pem_key = calloc(keylen+1, 1); /* Null-terminate */
	BIO_read(bio, pem_key, keylen);

	printf("%s", pem_key);

	BIO_free_all(bio);
	RSA_free(rsa);
	free(pem_key);
	return 0;
}

#include <openssl/rsa.h>

#include <openssl/pem.h>

int main(){

const int kBits = 1024;

const int kExp = 3;

int keylen;

char *pem_key;

RSA *rsa = RSA_generate_key(kBits, kExp, 0, 0);

/* To get the C-string PEM form: */

BIO *bio = BIO_new(BIO_s_mem());

PEM_write_bio_RSAPrivateKey(bio, rsa, NULL, NULL, 0, NULL, NULL);

keylen = BIO_pending(bio);

pem_key = calloc(keylen+1, 1); /* Null-terminate */

BIO_read(bio, pem_key, keylen);

printf("%s", pem_key);

BIO_free_all(bio);

RSA_free(rsa);

free(pem_key);

return 0;

}

C, Linux

Breadth first search

admin / 27 May, 2018

Steps: Add root to queue If left child not null, add it to queue If right child not null, add it to queue Repeat 2 & 3 until the queue is empty

void print_tree_bfs() {
    queue<Node *> q;
    Node *cur = this->root;
    q.push(cur);
    while (!q.empty()) {
        cur = q.front();
        cout << cur->data << " ";
        if (cur->left)
            q.push(cur->left);
        if (cur->right)
            q.push(cur->right);
        q.pop();
    }
}

void print_tree_bfs() {

queue<Node *> q;

Node *cur = this->root;

q.push(cur);

while (!q.empty()) {

cur = q.front();

cout << cur->data << " ";

if (cur->left)

q.push(cur->left);

if (cur->right)

q.push(cur->right);

q.pop();

}

C, C++, Language

CMake command

admin / 26 May, 2018

Set variable Basic usage of SET

SET(GCC_PATH    /usr/bin/gcc)
# SET variable "GCC_PATH" to "/usr/bin/gcc"

1 2	SET(GCC_PATH /usr/bin/gcc) # SET variable "GCC_PATH" to "/usr/bin/gcc"

To include existing variables in the SET

SET(GCC_VERSION    ${GCC_PATH}_7_2)
# Use ${...}
# GCC_VERSION is now SET to "/usr/bin/gcc_7_2")

SET(GCC_VERSION ${GCC_PATH}_7_2)

# Use ${...}

# GCC_VERSION is now SET to "/usr/bin/gcc_7_2")

To include multiple items in SET

SET(CUSTOM_FLAGS
    -Wall
    -Wextra
    -std=c11
)

# OR 

SET(CUSTOM_FLAGS    -Wall -Wextra -std=c11)

SET(CUSTOM_FLAGS

-Wall

-Wextra

-std=c11

)

# OR

SET(CUSTOM_FLAGS -Wall -Wextra -std=c11)

Include include path (header) Suppose we have the header files like this

/openssl/include/foo.h
/openssl/include/bar.h

/googletest/include/abc.h
/googletest/include/def.h

/openssl/include/foo.h

/openssl/include/bar.h

/googletest/include/abc.h

/googletest/include/def.h

To globally add the include path, use include_directories

include_directories(
    /openssl/include
    /googletest/include
)

include_directories(

/openssl/include

/googletest/include

)

To specially add the include path for target, use target_include_directories

target_include_directories(
    EXAMPLE_TARGET_NAME
    /openssl/include
    /googletest/include
)

target_include_directories(

EXAMPLE_TARGET_NAME

/openssl/include

/googletest/include

)

…

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C++

Filenames should be all lowercase with underscores (_) or dashes (-) hello_world.cc All types like classes, structs, type aliases, enums, and type should be capitalized. class Person Variables should be all lowercase with underscores string table_name Data member in the class (not struct) should contain a trailing underscores string var_in_class_ Use a struct only for passive objects that carry…

Continue Reading→

C++

C++ 11

admin / 10 May, 2018

Auto type

// BEFORE
for(vector<Person>::iterator it = personVec.begin(); it != personVec.end(); it++)
{...}

// IN C++ 11
for(auto it = personVec.begin(); it != personVec.end(); it++)
{...}

// BEFORE

for(vector<Person>::iterator it = personVec.begin(); it != personVec.end(); it++)

{...}

// IN C++ 11

for(auto it = personVec.begin(); it != personVec.end(); it++)

{...}

Auto type + Ranged-based for loop

// BEFORE
int i = 0;
for(vector<Person>::iterator it = personVec.begin(); it != personVec.end(); it++, i++){
    personVec[i].printName();
}

// IN C++ 11 *Work only for container with begin() and end()
//     Read only access
for(auto person : personVec){
     person.printName();
}

//     To write
for(auto& person : personVec){
     person.name = "Overwritten";
}

// BEFORE

int i = 0;

for(vector<Person>::iterator it = personVec.begin(); it != personVec.end(); it++, i++){

personVec[i].printName();

}

// IN C++ 11 *Work only for container with begin() and end()

// Read only access

for(auto person : personVec){

person.printName();

}

// To write

for(auto& person : personVec){

person.name = "Overwritten";

}

Initializer list

// BEFORE
personVec.push_back(person1);
personVec.push_back(person2);
personVec.push_back(person3);

// IN C++ 11
personVec = { person1, person2, person3 }

// BEFORE

personVec.push_back(person1);

personVec.push_back(person2);

personVec.push_back(person3);

// IN C++ 11

personVec = { person1, person2, person3 }

Strongly-typed enum

// BEFORE
enum Color{ cRed, cGreen };
Color mcolor = cRed;

// IN C++ 11
enum struct Color{ Red, Green };
Color mcolor = Color::Red;

// BEFORE

enum Color{ cRed, cGreen };

Color mcolor = cRed;

// IN C++ 11

enum struct Color{ Red, Green };

Color mcolor = Color::Red;

Compile time assert

// Before C++ 11, it provides only the run time assert
assert( a == 0 ); // Terminate program if a == 0

// IN C++ 11
static_assert( a == 0 ); // Compile time assert

// Before C++ 11, it provides only the run time assert

assert( a == 0 ); // Terminate program if a == 0

// IN C++ 11

static_assert( a == 0 ); // Compile time assert

Gatekeeper

[Method]alloc_and_fill_notify_pkt

admin / 2 May, 2018

Depending on the ethertype, by using rte_pktmbuf_append, the following component will be packed into the packet accordingly. static inline char *rte_pktmbuf_append(struct rte_mbuf *m, uint16_t len) It takes the memory buffer and the its length. It returns the pointer to tail after the insertion of data. notify_pkt is composed by: link layer header ipv4/ipv6 header udp header ggu_common header

C, Gatekeeper, Linux

Gatekeeper [Network setup]

admin / 18 February, 2018

DPDK(network setup) Add two virtual network interfaces in settings in Virtual Box

"Network > Adapter x"
Attached to : Bridged Adapter

"Advanced"
Adapter Type : Intel PRO/1000 MT Server (82545EM)

"Network > Adapter x"

Attached to : Bridged Adapter

"Advanced"

Adapter Type : Intel PRO/1000 MT Server (82545EM)

Check if the network interfaces have been successfully mapped into lua/if_map.lua

return {
        ["enp0s3"] = "0000:00:03.0",
        ["enp0s8"] = "0000:00:08.0",
        ["enp0s9"] = "0000:00:09.0",
}

return {

["enp0s3"] = "0000:00:03.0",

["enp0s8"] = "0000:00:08.0",

["enp0s9"] = "0000:00:09.0",

}

Check the network devices status using dpdk-devbind.py under gatekeeper/dependencies/dpdk/tools

python dependencies/dpdk/tools/dpdk-devbind.py --status

1	python dependencies/dpdk/tools/dpdk-devbind.py --status

Load the module vfio-pci / uio_pci_generic

sudo modprobe uio_pci_generic
## OR ##
sudo modprobe vfio-pci

sudo modprobe uio_pci_generic

## OR ##

sudo modprobe vfio-pci

Gatekeeper setup (DPDK)

admin / 13 February, 2018

Background The system has been built using these four Linux distributions.

Fedora 27
Kali Linux
Arch Linux
Kbuntu (KDE version of Ubuntu)

Fedora 27

Kali Linux

Arch Linux

Kbuntu (KDE version of Ubuntu)

Thank to the suggestions, I have finally decided to use Kubuntu as the major compilation issues are directly related to the latest version of gcc compiler, i.e. gcc >7, together with latest Linux kernel. The platform that I have chosen:

Kubuntu 16.04.3 LTS
gcc (Ubuntu 5.4.0-6ubuntu1~16.04.6) 5.4.0 20160609
linux_kernel (4.10.0-28-generic)

Kubuntu 16.04.3 LTS

gcc (Ubuntu 5.4.0-6ubuntu1~16.04.6) 5.4.0 20160609

linux_kernel (4.10.0-28-generic)

Setup Dependency (gatekeeper) To…

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Fix, Windows

Recover corrupted USB from format of other OS to windows

admin / 7 February, 2018

Call diskpart utility In Windows cmd.exe

diskpart

diskpart

To see the list of disk attached

DISKPART> list disk


  Disk ###  Status         Size     Free     Dyn  Gpt
  --------  -------------  -------  -------  ---  ---
  Disk 0    Online          119 GB      0 B
  Disk 1    Online          931 GB      0 B
  Disk 2    Online         7640 MB  7639 MB

DISKPART> list disk

Disk ### Status Size Free Dyn Gpt

-------- ------------- ------- ------- --- ---

Disk 0 Online 119 GB 0 B

Disk 1 Online 931 GB 0 B

Disk 2 Online 7640 MB 7639 MB

Select the disk as target and rebuild the partition

DISKPART> select disk 2

Disk 2 is now the selected disk.

DISKPART> create partition primary

DiskPart succeeded in creating the specified partition.

DISKPART> active

DiskPart marked the current partition as active.

DISKPART> select disk 2

Disk 2 is now the selected disk.

DISKPART> create partition primary

DiskPart succeeded in creating the specified partition.

DISKPART> active

DiskPart marked the current partition as active.

Select the partition 1 built and format the disk, for example, FAT32

DISKPART> select partition 1

Partition 1 is now the selected partition.

DISKPART> format fs=fat32

  100 percent completed

DiskPart successfully formatted the volume.

DISKPART> select partition 1

Partition 1 is now the selected partition.

DISKPART> format fs=fat32

100 percent completed

DiskPart successfully formatted the volume.

[libressl] Generate RSA key

[libressl] Setup

Breadth first search

CMake command

Google C++ style guide

C++ 11

[Method]alloc_and_fill_notify_pkt

Gatekeeper [Network setup]

Gatekeeper setup (DPDK)

Recover corrupted USB from format of other OS to windows