This tutorial will guide you on how to hash a string by using OpenSSL’s SHA hash function. This tutorial will create two C++ example files which will compile and run in Ubuntu environment.
- Here are the openssl SHA sample source code.
Example #1: sha_sample1.cpp1234567891011121314151617181920#include <stdio.h>#include <string.h>#include <openssl/sha.h>int main(){unsigned char digest[SHA_DIGEST_LENGTH];char string[] = "hello world";SHA((unsigned char*)&string, strlen(string), (unsigned char*)&digest);char mdString[SHA_DIGEST_LENGTH*2+1];for(int i = 0; i < SHA_DIGEST_LENGTH; i++)sprintf(&mdString[i*2], "%02x", (unsigned int)digest[i]);printf("SHA digest: %s\n", mdString);return 0;}
Example #2: sha_sample2.cpp12345678910111213141516171819202122#include <stdio.h>#include <string.h>#include <openssl/sha.h>int main() {unsigned char digest[SHA_DIGEST_LENGTH];const char* string = "hello world";SHA_CTX ctx;SHA_Init(&ctx);SHA_Update(&ctx, string, strlen(string));SHA_Final(digest, &ctx);char mdString[SHA_DIGEST_LENGTH*2+1];for (int i = 0; i < SHA_DIGEST_LENGTH; i++)sprintf(&mdString[i*2], "%02x", (unsigned int)digest[i]);printf("SHA digest: %s\n", mdString);return 0;} - Let’s try to compile both sample cpp files and you should observe the following output screenshot.
Note: -lcrypto will include the crypto library from openssl~$ gcc sha_sample1.cpp -o sample1 -lcrypto
~$ ./sample1
SHA digest: 9fce82c34887c1953b40b3a2883e18850c4fa8a6
~$ gcc sha_sample2.cpp -o sample2 -lcrypto
~$ ./sample2
SHA digest: 9fce82c34887c1953b40b3a2883e18850c4fa8a6
OpenSSL SHA Hashing Example in C++