> -----Original Message----- > From: owner-openssl-us...@openssl.org > [mailto:owner-openssl-us...@openssl.org] On Behalf Of Bizhan > Gholikhamseh (bgholikh) > Sent: Wednesday, July 08, 2009 5:38 PM > To: openssl-users@openssl.org > Subject: RE: Need help please: calculate SHA256. > > > > > -----Original Message----- > > From: owner-openssl-us...@openssl.org > > [mailto:owner-openssl-us...@openssl.org] On Behalf Of David Schwartz > > Sent: Wednesday, July 08, 2009 3:05 PM > > To: openssl-users@openssl.org > > Subject: RE: Need help please: calculate SHA256. > > > > > > Bizhan Gholikhamseh wrote: > > > > > Hi all, > > > I have an image that I need to calculate SHA256 has > digest of image > > > and encrypt the hash digest using my private key to > generate image > > > signature. > > > > > > Could someone please let me know how to use openssl to do this? > > > > 1) Calculate the SHA256 hash. > > > > 2) Sign it with the private key. > > > > If you want a more specific answer, you're going to have to > ask a more > > specific question. > > I have a text file, let us call it test.tx, which I need to > send it through a secure mechanism to a remote site. > I have already created a pair of public and private rsa key > using openssl. > I want to use openssl to generate a sha256 hash digest of the > text file, i.e. test.tx --> test.hash. > And encrypt the hash file with my private key i.e. test.hash > --> test.sign. > I believe this process is called signing the image (I am very > new in this area). > > Any help greatly appreciated,
Here are a series of openssl commands you can use to encrypt and generate a hash. I used AES-256 and SHA-384 in the example given. 1. echo "Hello" >foobar.txt 2. Encrypt: openssl aes256 -salt -in foobar.txt -out scrambled.txt 3. Decrypt: openssl aes256 -d -in scrambled.txt 4. Hash of Plaintext: openssl dgst -sha384 foobar.txt - 1d283e09aa7e597f2c0505c13f7c09eb4d4cd198fb7b144eeea2824cc59a046d9363b3f0 38abf7aa6bde7f8adaf561a4 5. Hash of Ciphertext: openssl dgst -sha384 scrambled.txt - 27e251831d2fb862ca092e4f0dacadb5fe3954240e377c387e4e903a25a492ed2129106b 993fb94fa709f7ca942e433f 6. ls -ltr foobar.txt - 6 bytes scrambed.txt - 32 bytes > > --B > > > > > > Are you trying to write a program? Are you trying to use > the 'openssl' > > application? Is there some specific image signing format > you're trying > > to use? Who or what is supposed to be able to verify this signature > > and using what format? > > > > Your question is like "how can I use steel to build a > bridge". You get > > the steel and you form it into a bridge with tools. > > > > DS > > ______________________________________________________________________ OpenSSL Project http://www.openssl.org User Support Mailing List openssl-users@openssl.org Automated List Manager majord...@openssl.org
