Add some examples.

This commit is contained in:
Dr. Stephen Henson 2006-07-08 12:46:51 +00:00
parent 6535bd42e6
commit 436369100d
5 changed files with 156 additions and 6 deletions

View File

@ -45,7 +45,37 @@ indicates the operation is not supported by the public key algorithm.
Decrypt data using OAEP (for RSA keys):
[to be added]
#include <openssl/evp.h>
#include <openssl/rsa.h>
EVP_PKEY_CTX *ctx;
unsigned char *out, *in;
size_t outlen, inlen;
EVP_PKEY *key;
/* NB: assumes key in, inlen are already set up
* and that key is an RSA private key
*/
ctx = EVP_PKEY_CTX_new(key);
if (!ctx)
/* Error occurred */
if (EVP_PKEY_decrypt_init(ctx) <= 0)
/* Error */
if (EVP_PKEY_CTX_set_rsa_padding(ctx, RSA_OAEP_PADDING) <= 0)
/* Error */
/* Determine buffer length */
if (EVP_PKEY_decrypt(ctx, NULL, &outlen, in, inlen) <= 0)
/* Error */
out = OPENSSL_malloc(outlen);
if (!out)
/* malloc failure */
if (EVP_PKEY_decrypt(ctx, out, &outlen, in, inlen) <= 0)
/* Error */
/* Decrypted data is outlen bytes written to buffer out */
=head1 SEE ALSO

View File

@ -45,7 +45,37 @@ indicates the operation is not supported by the public key algorithm.
Encrypt data using OAEP (for RSA keys):
[to be added]
#include <openssl/evp.h>
#include <openssl/rsa.h>
EVP_PKEY_CTX *ctx;
unsigned char *out, *in;
size_t outlen, inlen;
EVP_PKEY *key;
/* NB: assumes key in, inlen are already set up
* and that key is an RSA public key
*/
ctx = EVP_PKEY_CTX_new(key);
if (!ctx)
/* Error occurred */
if (EVP_PKEY_encrypt_init(ctx) <= 0)
/* Error */
if (EVP_PKEY_CTX_set_rsa_padding(ctx, RSA_OAEP_PADDING) <= 0)
/* Error */
/* Determine buffer length */
if (EVP_PKEY_encrypt(ctx, NULL, &outlen, in, inlen) <= 0)
/* Error */
out = OPENSSL_malloc(outlen);
if (!out)
/* malloc failure */
if (EVP_PKEY_encrypt(ctx, out, &outlen, in, inlen) <= 0)
/* Error */
/* Encrypted data is outlen bytes written to buffer out */
=head1 SEE ALSO

View File

@ -43,9 +43,42 @@ indicates the operation is not supported by the public key algorithm.
=head1 EXAMPLE
Sign data using PKCS#1 and SHA256 digest:
Sign data using RSA with PKCS#1 padding and SHA256 digest:
#include <openssl/evp.h>
#include <openssl/rsa.h>
EVP_PKEY_CTX *ctx;
unsigned char *md, *sig;
size_t mdlen, siglen;
EVP_PKEY *signing_key;
/* NB: assumes signing_key, md and mdlen are already set up
* and that signing_key is an RSA private key
*/
ctx = EVP_PKEY_CTX_new(signing_key);
if (!ctx)
/* Error occurred */
if (EVP_PKEY_sign_init(ctx) <= 0)
/* Error */
if (EVP_PKEY_CTX_set_rsa_padding(ctx, RSA_PKCS1_PADDING) <= 0)
/* Error */
if (EVP_PKEY_CTX_set_signature_md(ctx, EVP_sha256()) <= 0)
/* Error */
/* Determine buffer length */
if (EVP_PKEY_sign(ctx, NULL, &siglen, md, mdlen) <= 0)
/* Error */
sig = OPENSSL_malloc(siglen);
if (!sig)
/* malloc failure */
if (EVP_PKEY_sign(ctx, sig, &siglen, md, mdlen) <= 0)
/* Error */
/* Signature is siglen bytes written to buffer sig */
[to be added]
=head1 SEE ALSO

View File

@ -48,7 +48,32 @@ the public key algorithm.
Verify signature using PKCS#1 and SHA256 digest:
[to be added]
#include <openssl/evp.h>
#include <openssl/rsa.h>
EVP_PKEY_CTX *ctx;
unsigned char *md, *sig;
size_t mdlen, siglen;
EVP_PKEY *verify_key;
/* NB: assumes verify_key, sig, siglen md and mdlen are already set up
* and that verify_key is an RSA public key
*/
ctx = EVP_PKEY_CTX_new(verify_key);
if (!ctx)
/* Error occurred */
if (EVP_PKEY_verify_init(ctx) <= 0)
/* Error */
if (EVP_PKEY_CTX_set_rsa_padding(ctx, RSA_PKCS1_PADDING) <= 0)
/* Error */
if (EVP_PKEY_CTX_set_signature_md(ctx, EVP_sha256()) <= 0)
/* Error */
/* Perform operation */
ret = EVP_PKEY_verify(ctx, md, mdlen, sig, siglen);
/* ret == 1 indicates success, 0 verify failure and < 0 for some
* other error.
*/
=head1 SEE ALSO

View File

@ -53,7 +53,39 @@ indicates the operation is not supported by the public key algorithm.
Recover digest originally signed using PKCS#1 and SHA256 digest:
[to be added]
#include <openssl/evp.h>
#include <openssl/rsa.h>
EVP_PKEY_CTX *ctx;
unsigned char *rout, *sig;
size_t routlen, siglen;
EVP_PKEY *verify_key;
/* NB: assumes verify_key, sig and siglen are already set up
* and that verify_key is an RSA public key
*/
ctx = EVP_PKEY_CTX_new(verify_key);
if (!ctx)
/* Error occurred */
if (EVP_PKEY_verifyrecover_init(ctx) <= 0)
/* Error */
if (EVP_PKEY_CTX_set_rsa_padding(ctx, RSA_PKCS1_PADDING) <= 0)
/* Error */
if (EVP_PKEY_CTX_set_signature_md(ctx, EVP_sha256()) <= 0)
/* Error */
/* Determine buffer length */
if (EVP_PKEY_verifyrecover(ctx, rout, &routlen, sig, siglen) <= 0)
/* Error */
rout = OPENSSL_malloc(routlen);
if (!rout)
/* malloc failure */
if (EVP_PKEY_verifyrecover(ctx, rout, &routlen, sig, siglen) <= 0)
/* Error */
/* Recovered data is routlen bytes written to buffer rout */
=head1 SEE ALSO