Re: [openssl-users] One question about RSA decrypt with private key

2017-03-23 Thread Salz, Rich via openssl-users 
> For encrypting user data such as user's password, could I use PKCS#1 or OAEP 
> padding mode?

If you do not know what you are doing, use the defaults.


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Re: [openssl-users] One question about RSA decrypt with private key

2017-03-23 Thread Yu Wei 
Hi Matt,


I checked openssl source code. It seems that PKCS#1 is default padding mode.

For encrypting user data such as user's password, could I use PKCS#1 or OAEP 
padding mode?



Thanks,

Jared, (韦煜）
Software developer
Interested in open source software, big data, Linux


From: openssl-users <openssl-users-boun...@openssl.org> on behalf of Matt 
Caswell <m...@openssl.org>
Sent: Thursday, March 23, 2017 6:05:43 PM
To: openssl-users@openssl.org
Subject: Re: [openssl-users] One question about RSA decrypt with private key



On 23/03/17 05:29, Yu Wei wrote:
> After commented out the line "EVP_PKEY_CTX_set_rsa_padding(ctx,
> RSA_NO_PADDING)",  it worked well.
>
>
> However, I still quite understand the usage of "RSA_NO_PADDING".
>
>
> Who could kindly explain this?
>

RSA_NO_PADDING gives you "raw" RSA encryption. From the manual:

RSA_NO_PADDING
Raw RSA encryption. This mode should only be used to implement
cryptographically sound padding modes in the application code.
Encrypting user data directly with RSA is insecure.

https://www.openssl.org/docs/man1.1.0/crypto/RSA_public_encrypt.html

Basically, unless you are implementing a new RSA padding mode, or really
know what you are doing, don't use it.

Matt


> Thanks,
>
> Jared, (韦煜）
> Software developer
> Interested in open source software, big data, Linux
>
> 
> *From:* openssl-users <openssl-users-boun...@openssl.org> on behalf of
> Yu Wei <yu20...@hotmail.com>
> *Sent:* Thursday, March 23, 2017 1:20:42 AM
> *To:* openssl-users@openssl.org
> *Subject:* [openssl-users] One question about RSA decrypt with private key
>
>
> Hi guys,
>
>
> I generated RSA private key and public key as below,
>
> openssl genpkey -algorithm RSA -out key.pem -pkeyopt rsa_keygen_bits:2048
>
> openssl rsa -pubout -in pri.key -out pub.key
>
>
> And encrypted text file as below,
>
> openssl pkeyutl -encrypt -pubin -inkey ~/pub.key -in ~/1.txt -out ~/1e.txt
>
>
> Then I wrote below program to decrypt the encryted file. However, it
> seemed that decrypt didn't work as  expected.
>
>
> #include 
> #include 
> #include 
> #include 
> #include 
> #include 
>
> using namespace std;
>
> void
> cleanup()
> {
> EVP_cleanup();
> CRYPTO_cleanup_all_ex_data();
> ERR_free_strings();
> }
>
> int
> main(int argc, char** argv)
> {
> ERR_load_crypto_strings();
> OpenSSL_add_all_algorithms();
> OPENSSL_config(nullptr);
>
> cout<<"Initialize crypto library done"<<endl;
>
> EVP_PKEY * key = EVP_PKEY_new();
> if (key == nullptr) {
> cout<<"Failed to contruct new key"<<endl;
> return 1;
> }
> FILE * fpri = nullptr;
> fpri = fopen("/home/stack/pri.key", "r");
> if (fpri == nullptr) {
> cout<<"Failed to load private key"<<endl;
> return 1;
> }
> key = PEM_read_PrivateKey(fpri, , nullptr, nullptr);
> if (key == nullptr) {
> std::cout<<"Read private key failed"<<endl;
> return 1;
> }
> cout<<"load private key successfully"<<endl;
> EVP_PKEY_CTX *ctx = nullptr;
> ctx = EVP_PKEY_CTX_new(key, nullptr);
> EVP_PKEY_decrypt_init(ctx);
> EVP_PKEY_CTX_set_rsa_padding(ctx, RSA_NO_PADDING);
>
> size_t outlen = 0, inlen = 0;
> unsigned char * out = nullptr, * in = nullptr;
>
> char buf[1024];
> FILE * fe = nullptr;
> fe = fopen("/home/stack/1e.txt", "r");
> size_t len = fread(buf, 1, sizeof(buf),  fe);
> cout<<"data input length is "<<len<<endl;
> EVP_PKEY_decrypt(ctx, NULL, , in, inlen);
> cout<<"outlen is "<<outlen<<endl;
>
> out = (unsigned char*)OPENSSL_malloc(outlen);
> EVP_PKEY_decrypt(ctx, out, , in, inlen);
> cout<<"decrypted data "<<out<<endl;
> cleanup();
>
> return 0;
>
> }
>
>
> When executing the code, the result is as below,
>
> [stack@agent ~]$ ./test
> Initialize crypto library done
> load private key successfully
> data input length is 256
> outlen is 256
> decrypted data
>
>
> Is there anything missed?
>
>
> Thanks,
>
> Jared, (韦煜）
> Software developer
> Interested in open source software, big data, Linux
>
>
>
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Re: [openssl-users] One question about RSA decrypt with private key

2017-03-23 Thread Salz, Rich via openssl-users 
> After commented out the line "EVP_PKEY_CTX_set_rsa_padding(ctx, 
> RSA_NO_PADDING)",? it worked well.

You need to do some reading about basic RSA cryptography.  Signatures are 
padded out to the keysize.
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Re: [openssl-users] One question about RSA decrypt with private key

2017-03-23 Thread Matt Caswell 


On 23/03/17 05:29, Yu Wei wrote:
> After commented out the line "EVP_PKEY_CTX_set_rsa_padding(ctx,
> RSA_NO_PADDING)",  it worked well.
> 
> 
> However, I still quite understand the usage of "RSA_NO_PADDING".
> 
> 
> Who could kindly explain this?
> 

RSA_NO_PADDING gives you "raw" RSA encryption. From the manual:

RSA_NO_PADDING
Raw RSA encryption. This mode should only be used to implement
cryptographically sound padding modes in the application code.
Encrypting user data directly with RSA is insecure.

https://www.openssl.org/docs/man1.1.0/crypto/RSA_public_encrypt.html

Basically, unless you are implementing a new RSA padding mode, or really
know what you are doing, don't use it.

Matt


> Thanks,
> 
> Jared, (韦煜）
> Software developer
> Interested in open source software, big data, Linux
> 
> 
> *From:* openssl-users  on behalf of
> Yu Wei 
> *Sent:* Thursday, March 23, 2017 1:20:42 AM
> *To:* openssl-users@openssl.org
> *Subject:* [openssl-users] One question about RSA decrypt with private key
>  
> 
> Hi guys,
> 
> 
> I generated RSA private key and public key as below,
> 
> openssl genpkey -algorithm RSA -out key.pem -pkeyopt rsa_keygen_bits:2048
> 
> openssl rsa -pubout -in pri.key -out pub.key
> 
> 
> And encrypted text file as below,
> 
> openssl pkeyutl -encrypt -pubin -inkey ~/pub.key -in ~/1.txt -out ~/1e.txt
> 
> 
> Then I wrote below program to decrypt the encryted file. However, it
> seemed that decrypt didn't work as  expected.
> 
> 
> #include 
> #include 
> #include 
> #include 
> #include 
> #include 
> 
> using namespace std;
> 
> void
> cleanup()
> {
> EVP_cleanup();
> CRYPTO_cleanup_all_ex_data();
> ERR_free_strings();
> }
> 
> int
> main(int argc, char** argv)
> {
> ERR_load_crypto_strings();
> OpenSSL_add_all_algorithms();
> OPENSSL_config(nullptr);
> 
> cout<<"Initialize crypto library done"< 
> EVP_PKEY * key = EVP_PKEY_new();
> if (key == nullptr) {
> cout<<"Failed to contruct new key"< return 1;
> }
> FILE * fpri = nullptr;
> fpri = fopen("/home/stack/pri.key", "r");
> if (fpri == nullptr) {
> cout<<"Failed to load private key"< return 1;
> }
> key = PEM_read_PrivateKey(fpri, , nullptr, nullptr);
> if (key == nullptr) {
> std::cout<<"Read private key failed"< return 1;
> }
> cout<<"load private key successfully"< EVP_PKEY_CTX *ctx = nullptr;
> ctx = EVP_PKEY_CTX_new(key, nullptr);
> EVP_PKEY_decrypt_init(ctx);
> EVP_PKEY_CTX_set_rsa_padding(ctx, RSA_NO_PADDING);
> 
> size_t outlen = 0, inlen = 0;
> unsigned char * out = nullptr, * in = nullptr;
> 
> char buf[1024];
> FILE * fe = nullptr;
> fe = fopen("/home/stack/1e.txt", "r");
> size_t len = fread(buf, 1, sizeof(buf),  fe);
> cout<<"data input length is "< EVP_PKEY_decrypt(ctx, NULL, , in, inlen);
> cout<<"outlen is "< 
> out = (unsigned char*)OPENSSL_malloc(outlen);
> EVP_PKEY_decrypt(ctx, out, , in, inlen);
> cout<<"decrypted data "< cleanup();
> 
> return 0;
> 
> }
> 
> 
> When executing the code, the result is as below,
> 
> [stack@agent ~]$ ./test
> Initialize crypto library done
> load private key successfully
> data input length is 256
> outlen is 256
> decrypted data
> 
> 
> Is there anything missed?
> 
> 
> Thanks,
> 
> Jared, (韦煜）
> Software developer
> Interested in open source software, big data, Linux
> 
> 
> 
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Re: [openssl-users] One question about RSA decrypt with private key

2017-03-23 Thread Yu Wei 
After commented out the line "EVP_PKEY_CTX_set_rsa_padding(ctx, 
RSA_NO_PADDING)",  it worked well.


However, I still quite understand the usage of "RSA_NO_PADDING".


Who could kindly explain this?


Thanks,

Jared, (韦煜）
Software developer
Interested in open source software, big data, Linux


From: openssl-users  on behalf of Yu Wei 

Sent: Thursday, March 23, 2017 1:20:42 AM
To: openssl-users@openssl.org
Subject: [openssl-users] One question about RSA decrypt with private key


Hi guys,


I generated RSA private key and public key as below,

openssl genpkey -algorithm RSA -out key.pem -pkeyopt rsa_keygen_bits:2048

openssl rsa -pubout -in pri.key -out pub.key


And encrypted text file as below,

openssl pkeyutl -encrypt -pubin -inkey ~/pub.key -in ~/1.txt -out ~/1e.txt


Then I wrote below program to decrypt the encryted file. However, it seemed 
that decrypt didn't work as  expected.


#include 
#include 
#include 
#include 
#include 
#include 

using namespace std;

void
cleanup()
{
EVP_cleanup();
CRYPTO_cleanup_all_ex_data();
ERR_free_strings();
}

int
main(int argc, char** argv)
{
ERR_load_crypto_strings();
OpenSSL_add_all_algorithms();
OPENSSL_config(nullptr);

cout<<"Initialize crypto library done"<