openssl « Development « C File Q&A

1. Load RSA keys from files    stackoverflow.com

I used openSSL command to create 2 files: 1 for RSA public key & 1 for RSA private key. How do I recover RSA keys using C? Specifically, I have these functions:

RSA_public_encrypt(read_num, ...

2. How to convert pkcs8 key file to DER format in #C?    stackoverflow.com

How to convert pkcs8 key file to DER format, to get Private and Public key in Xml format? with openssl I can do it using: openssl pkcs8 -inform DER -in aaa010101aaa_FIEL.key -out aaa.txt aaa010101aaa_FIEL.key ...

3. Need sample C code for encrypting and decrypting files using openssl    stackoverflow.com

Am writing code in Linux C. I need to encrypt and decrypt files using openssl. Currently Am using system command "des3 -e -nosalt -k 0123456789012345 -in inp_file -out out_file" for encrypting ...

4. base64 file digest calculation with openssl    stackoverflow.com

I am trying to figure out the way to code the following openssl commands: Scenario: Given: Base64 encoded value of a file (b64.txt) Base64 encoded sha1 digest of the file(exactly 20 byte sha1 ...

5. Encrypting a file using openssl with a password in C    stackoverflow.com

Iam having a text file. I need to encrypt that file with a password. In command line (-k for password and -nosalt -des3) are being used. Is there any sample to achieve the ...

6. base64 decoding files of length greater than 8192?    stackoverflow.com

Whenever I try to base64 decode files (using OpenSSL's BIO_f_base64()) larger than 8192, I always seem to get some wrong value. What is with this magic number 8192? Any help to educate ...

7. Where is the PEM file format specified?    stackoverflow.com

I need to parse .PEM files.
I know that the standard for "Privacy-enhanced Electronic Mail" is defined in RFCs 1421-24. But they don't seem to mention some text I find inside OpenSSL ...

8. AES Encryption- large files    stackoverflow.com

I am doing AES encryption using EVP interface of OpenSSL in C language in the 128/192/256 cbc modes. I found a nice example in stackoverflow with which I have started programming. What I ...

9. set private and public EC key with OpenSSL from files    stackoverflow.com

I am making a program which generates a key pair priva and puba for the sender and privb and pubb for the receiver, then I export each one to a file, ...

10. Save X509 certificate to a file    stackoverflow.com

I am working on a HTTPS client and I managed to establish a secure connection and get the X509 certificate using "X509 *cert = SSL_get_certificate(ssl);" (ssl is SSL*). How do I save ...

11. How to load a PKCS#12 file in OpenSSL programmatically?    stackoverflow.com

In an SSL Server Application based on OpenSSL, how can we load a PKCS#12 file programmatically? Also, can I load a PKCS#12 file having Certificate, Key & CAs in the same file ...

12. How to sign a file using libssl?    stackoverflow.com

I want to create a signature for a file using OpenSSL. I believe that my result should match the testfile.sig generated by openssl this way:

$ openssl dgst -sha1 -binary < testfile > ...

13. openssl aes256 encryption of a file    stackoverflow.com

I'd like to encrypt a file with aes256 openssl with c. I did found a pretty nice example here. Should i first read the whole file into a men buffer and ...

14. Calculate SHA256 of a file using OpenSSL/libcrypto in C    stackoverflow.com

I'm trying to write a C function using OpenSSL/libcrypto to calculate the SHA256 sum of a file. I'm basing my code on Adam Lamer's c++ example here. Here's my code:

int ...