Saturday, February 27, 2021

setsockopt: Protocol not available [Solved]


Problem code:

if (setsockopt(server_fd, SOL_SOCKET, SO_REUSEADDR | SO_REUSEPORT, &opt, sizeof(opt))) 

perror("setsockopt"); 

exit(EXIT_FAILURE); 

}


Solution:

if (setsockopt(server_fd, SOL_SOCKET, SO_REUSEADDR, &opt, sizeof(opt))) 

perror("setsockopt"); 

exit(EXIT_FAILURE); 

}


Ref.: https://stackoverflow.com/a/59807281/4064166


Thursday, February 25, 2021

[How To] Fix "Waiting to Upload" in iCloud Drive


1. Check if you have enough free storage on iCloud

2. Go to Settings (iOS / iPadOS) or System Preferences (macOS) >> iCloud >> Sign Out

3. Wait for a minute or two after you have successfully logged out

4. Log in to iCloud again

5. Go to iCloud settings and >> iCloud Drive >> Options... >> select the checkbox for "Desktop & Documents Folder" >> Done

Monday, February 22, 2021

Best tablets to buy in 2021

iPad Air 2020 256 GB - https://amzn.to/2OVg49n

Brand - Apple

Storage - 256 GB

Display - 10.9"

Resolution - 2360 x 1640

Operating System - iPadOS 14


stylus pen for iPad with palm rejection - https://amzn.to/3aEluxP

iPad Air 4th generation keyboard case - https://amzn.to/3kbOT5D

iPad Air glass screen protector - https://amzn.to/3aG5xY1

[How To] Use Cryptopp in Xcode

  • Crypto++ Library is a free C++ class library of cryptographic schemes. Currently the library contains the following algorithms: algorithm type name authenticated encryption schemes GCM, CCM, EAX, ChaCha20Poly1305 and XChaCha20Poly1305 high speed stream ciphers ChaCha (8/12/20), ChaCha (IETF), Panama, Salsa20, Sosemanuk, XSalsa20, XChaCha20 AES and AES candidates AES (Rijndael), RC6, MARS, Twofish, Serpent, CAST-256 ARIA, Blowfish, Camellia, CHAM, HIGHT, IDEA, Kalyna (128/256/512), LEA, SEED, RC5, SHACAL-2, other block ciphers SIMON (64/128), Skipjack, SPECK (64/128), Simeck, SM4, Threefish (256/512/1024), Triple-DES (DES-EDE2 and DES-EDE3), TEA, XTEA block cipher modes of operation ECB, CBC, CBC ciphertext stealing (CTS), CFB, OFB, counter mode (CTR), XTS message authentication codes BLAKE2s, BLAKE2b, CMAC, CBC-MAC, DMAC, GMAC, HMAC, Poly1305, Poly1305 (IETF), SipHash, Two-Track-MAC, VMAC BLAKE2s, BLAKE2b, Keccack (F1600), SHA-1, hash functions SHA-2 (224/256/384/512), SHA-3 (224/256/384/512), SHAKE (128/256), SipHash, SM3, Tiger, RIPEMD (128/160/256/320), WHIRLPOOL RSA, DSA, Deterministic DSA, ElGamal, public-key cryptography Nyberg-Rueppel (NR), Rabin-Williams (RW), LUC, LUCELG, EC-based German Digital Signature (ECGDSA), DLIES (variants of DHAES), ESIGN padding schemes for public-key PKCS#1 v2.0, OAEP, PSS, PSSR, IEEE P1363 systems EMSA2 and EMSA5 Diffie-Hellman (DH), Unified Diffie-Hellman (DH2), key agreement schemes Menezes-Qu-Vanstone (MQV), Hashed MQV (HMQV), Fully Hashed MQV (FHMQV), LUCDIF, XTR-DH elliptic curve cryptography ECDSA, Deterministic ECDSA, ed25519, ECNR, ECIES, ECDH, ECMQV, x25519 insecure or obsolescent MD2, MD4, MD5, Panama Hash, DES, ARC4, SEAL algorithms retained for backwards 3.0, WAKE-OFB, DESX (DES-XEX3), RC2, compatibility and historical SAFER, 3-WAY, GOST, SHARK, CAST-128, Square value

Saturday, February 13, 2021

[How To] check if Intel SGX is enabled


Steps to check if Intel SGX is enabled on your system:

1. Download test-sgx.c from https://github.com/ayeks/SGX-hardware

2. % gcc test-sgx.c -o test-sgx

3. % ./test-sgx

eax: 806ea ebx: 4100800 ecx: 7ffafbbf edx: bfebfbff

stepping 10

model 14

family 6

processor type 0

extended model 8

extended family 0

smx: 0


Extended feature bits (EAX=07H, ECX=0H)

eax: 0 ebx: 29c67af ecx: 0 edx: 9c002600

sgx available: 1

sgx launch control: 0


CPUID Leaf 12H, Sub-Leaf 0 of Intel SGX Capabilities (EAX=12H,ECX=0)

eax: 0 ebx: 0 ecx: 0 edx: 0

sgx 1 supported: 0

sgx 2 supported: 0

MaxEnclaveSize_Not64: 0

MaxEnclaveSize_64: 0


CPUID Leaf 12H, Sub-Leaf 1 of Intel SGX Capabilities (EAX=12H,ECX=1)

eax: 0 ebx: 0 ecx: 0 edx: 0


CPUID Leaf 12H, Sub-Leaf 2 of Intel SGX Capabilities (EAX=12H,ECX=2)

eax: 0 ebx: 0 ecx: 0 edx: 0


CPUID Leaf 12H, Sub-Leaf 3 of Intel SGX Capabilities (EAX=12H,ECX=3)

eax: 0 ebx: 0 ecx: 0 edx: 0


CPUID Leaf 12H, Sub-Leaf 4 of Intel SGX Capabilities (EAX=12H,ECX=4)

eax: 0 ebx: 0 ecx: 0 edx: 0


CPUID Leaf 12H, Sub-Leaf 5 of Intel SGX Capabilities (EAX=12H,ECX=5)

eax: 0 ebx: 0 ecx: 0 edx: 0


CPUID Leaf 12H, Sub-Leaf 6 of Intel SGX Capabilities (EAX=12H,ECX=6)

eax: 0 ebx: 0 ecx: 0 edx: 0


CPUID Leaf 12H, Sub-Leaf 7 of Intel SGX Capabilities (EAX=12H,ECX=7)

eax: 0 ebx: 0 ecx: 0 edx: 0


CPUID Leaf 12H, Sub-Leaf 8 of Intel SGX Capabilities (EAX=12H,ECX=8)

eax: 0 ebx: 0 ecx: 0 edx: 0


CPUID Leaf 12H, Sub-Leaf 9 of Intel SGX Capabilities (EAX=12H,ECX=9)

eax: 0 ebx: 0 ecx: 0 edx: 0


4. sgx available = 1 means that the system has a CPU that supports Intel SGX


5. From sgx1 supported = 0 and max enclave size64 = 0 we infer that Intel SGX is disabled from BIOS

Wednesday, February 03, 2021

iOS v/s Android - Comparing 'Apples' to 'Oranges'


Apple iOS

Google Android

Released

July 29, 2007

September 23, 2008

Latest Version

14

11

Website

https://www.apple.com/ios/ios-14/

https://www.android.com/

OS Model

Proprietary

Open Source

Languages

40

100

Assistant

Siri

Google Assistant

Apps

1,000,000 on App Store

2,000,000 on Play Store

Operating System

Unix

Linux

Latest Phone

iPhone 12

Pixel 5

Phone Website

https://www.apple.com/iphone

https://store.google.com/product/pixel_5


Let's compare some of the default apps on both platforms...