Openssl Generate Public Key From Modulus And Exponent Rating: 10,0/10 4486 votes
  1. Openssl Generate Public Key From Modulus And Exponent Function
  2. Generate Public Key From Modulus And Exponent
toRSAPublicKey.c
#include<string.h>
#include<openssl/rsa.h>
#include<openssl/evp.h>
#include<openssl/bn.h>
#include<openssl/pem.h>
// cheating, . ignoring deprecation warnings
#pragma GCC diagnostic ignored '-Wdeprecated-declarations'
unsignedchar *base64_decode(constchar* base64data, int* len) {
BIO *b64, *bmem;
size_t length = strlen(base64data);
unsignedchar *buffer = (unsignedchar *)malloc(length);
b64 = BIO_new(BIO_f_base64());
BIO_set_flags(b64, BIO_FLAGS_BASE64_NO_NL);
bmem = BIO_new_mem_buf((void*)base64data, length);
bmem = BIO_push(b64, bmem);
*len = BIO_read(bmem, buffer, length);
BIO_free_all(bmem);
return buffer;
}
BIGNUM* bignum_base64_decode(constchar* base64bignum) {
BIGNUM* bn = NULL;
int len;
unsignedchar* data = base64_decode(base64bignum, &len);
if (len) {
bn = BN_bin2bn(data, len, NULL);
}
free(data);
return bn;
}
EVP_PKEY* RSA_fromBase64(constchar* modulus_b64, constchar* exp_b64) {
BIGNUM *n = bignum_base64_decode(modulus_b64);
BIGNUM *e = bignum_base64_decode(exp_b64);
if (!n) printf('Invalid encoding for modulusn');
if (!e) printf('Invalid encoding for public exponentn');
if (e && n) {
EVP_PKEY* pRsaKey = EVP_PKEY_new();
RSA* rsa = RSA_new();
rsa->e = e;
rsa->n = n;
EVP_PKEY_assign_RSA(pRsaKey, rsa);
return pRsaKey;
} else {
if (n) BN_free(n);
if (e) BN_free(e);
returnNULL;
}
}
voidassert_syntax(int argc, char** argv) {
if (argc != 4) {
fprintf(stderr, 'Description: %s takes a RSA public key modulus and exponent in base64 encoding and produces a public key file in PEM format.n', argv[0]);
fprintf(stderr, 'syntax: %s <modulus_base64> <exp_base64> <output_file>n', argv[0]);
exit(1);
}
}
intmain(int argc, char** argv) {
assert_syntax(argc, argv);
constchar* modulus = argv[1];
constchar* exp = argv[2];
constchar* filename = argv[3];
EVP_PKEY* pkey = RSA_fromBase64(modulus, exp);
if (pkey NULL) {
fprintf(stderr, 'an error occurred :(n');
return2;
} else {
printf('success decoded into RSA public keyn');
FILE* file = fopen(filename, 'w');
PEM_write_PUBKEY(file, pkey);
fflush(file);
fclose(file);
printf('written to file: %sn', filename);
}
return0;
}

Openssl Generate Public Key From Modulus And Exponent Function

Ms office 2010 product key generator.exe. Key sound generator windows 10. Openssl genrsa -des3 -out private.pem 1024 (Encrypts with a password-just remove '-des3' if you'd rather not have a password on the private key) openssl rsa in private.key -pubout -out public.pem (Generate public key) Abstract the common Modulus from the public key.

Sign up for freeto join this conversation on GitHub. Already have an account? Sign in to comment

Generate Public Key From Modulus And Exponent

  1. Walmart Partner API Authentication (Generate a Signature for a Request) Generate RSA Key and return Base64 PKCS8 Private Key; Convert RSA Private Key to Public Key; Get RSA Private Key in JWK Format (JSON Web Key) Get ECC Private Key in JWK Format (JSON Web Key) Get RSA Public Key in JWK Format (JSON Web Key) Get ECC Public Key in JWK Format.
  2. Oct 27, 2015  Create a public RSA key from modulus and exponent on the command line - gen-rsa-pubkey.sh.