=head1 NAME
-EVP_PKEY_encrypt_init, EVP_PKEY_encrypt - encrypt using a public key algorithm
+EVP_PKEY_sign_init, EVP_PKEY_sign - sign using a public key algorithm
=head1 SYNOPSIS
=head1 NOTES
+EVP_PKEY_sign() does not hash the data to be signed, and therefore is
+normally used to sign digests. For signing arbitrary messages, see the
+L<EVP_DigestSignInit(3)|EVP_DigestSignInit(3)> and
+L<EVP_SignInit(3)|EVP_SignInit(3)> signing interfaces instead.
+
After the call to EVP_PKEY_sign_init() algorithm specific control
operations can be performed to set any appropriate parameters for the
-operation.
+operation (see L<EVP_PKEY_CTX_ctrl(3)|EVP_PKEY_CTX_ctrl(3)>).
The function EVP_PKEY_sign() can be called more than once on the same
context if several operations are performed using the same parameters.
=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;
+ /* md is a SHA-256 digest in this example. */
+ unsigned char *md, *sig;
+ size_t mdlen = 32, siglen;
+ EVP_PKEY *signing_key;
+
+ /*
+ * NB: assumes signing_key and md are set up before the next
+ * step. signing_key must be an RSA private key and md must
+ * point to the SHA-256 digest to be signed.
+ */
+ ctx = EVP_PKEY_CTX_new(signing_key, NULL /* no engine */);
+ 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
L<EVP_PKEY_CTX_new(3)|EVP_PKEY_CTX_new(3)>,
+L<EVP_PKEY_CTX_ctrl(3)|EVP_PKEY_CTX_ctrl(3)>,
L<EVP_PKEY_encrypt(3)|EVP_PKEY_encrypt(3)>,
L<EVP_PKEY_decrypt(3)|EVP_PKEY_decrypt(3)>,
L<EVP_PKEY_verify(3)|EVP_PKEY_verify(3)>,
-L<EVP_PKEY_verifyrecover(3)|EVP_PKEY_verifyrecover(3)>,
+L<EVP_PKEY_verify_recover(3)|EVP_PKEY_verify_recover(3)>,
L<EVP_PKEY_derive(3)|EVP_PKEY_derive(3)>
=head1 HISTORY
-These functions were first added to OpenSSL 0.9.9.
+These functions were first added to OpenSSL 1.0.0.
=cut