Index: openssl/doc/crypto/EVP_PKEY_verify.pod |
=================================================================== |
--- openssl/doc/crypto/EVP_PKEY_verify.pod (revision 0) |
+++ openssl/doc/crypto/EVP_PKEY_verify.pod (revision 0) |
@@ -0,0 +1,91 @@ |
+=pod |
+ |
+=head1 NAME |
+ |
+EVP_PKEY_verify_init, EVP_PKEY_verify - signature verification using a public key algorithm |
+ |
+=head1 SYNOPSIS |
+ |
+ #include <openssl/evp.h> |
+ |
+ int EVP_PKEY_verify_init(EVP_PKEY_CTX *ctx); |
+ int EVP_PKEY_verify(EVP_PKEY_CTX *ctx, |
+ const unsigned char *sig, size_t siglen, |
+ const unsigned char *tbs, size_t tbslen); |
+ |
+=head1 DESCRIPTION |
+ |
+The EVP_PKEY_verify_init() function initializes a public key algorithm |
+context using key B<pkey> for a signature verification operation. |
+ |
+The EVP_PKEY_verify() function performs a public key verification operation |
+using B<ctx>. The signature is specified using the B<sig> and |
+B<siglen> parameters. The verified data (i.e. the data believed originally |
+signed) is specified using the B<tbs> and B<tbslen> parameters. |
+ |
+=head1 NOTES |
+ |
+After the call to EVP_PKEY_verify_init() algorithm specific control |
+operations can be performed to set any appropriate parameters for the |
+operation. |
+ |
+The function EVP_PKEY_verify() can be called more than once on the same |
+context if several operations are performed using the same parameters. |
+ |
+=head1 RETURN VALUES |
+ |
+EVP_PKEY_verify_init() and EVP_PKEY_verify() return 1 if the verification was |
+successful and 0 if it failed. Unlike other functions the return value 0 from |
+EVP_PKEY_verify() only indicates that the signature did not not verify |
+successfully (that is tbs did not match the original data or the signature was |
+of invalid form) it is not an indication of a more serious error. |
+ |
+A negative value indicates an error other that signature verification failure. |
+In particular a return value of -2 indicates the operation is not supported by |
+the public key algorithm. |
+ |
+=head1 EXAMPLE |
+ |
+Verify signature using PKCS#1 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 *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, sig, siglen, md, mdlen); |
+ |
+ /* ret == 1 indicates success, 0 verify failure and < 0 for some |
+ * other error. |
+ */ |
+ |
+=head1 SEE ALSO |
+ |
+L<EVP_PKEY_CTX_new(3)|EVP_PKEY_CTX_new(3)>, |
+L<EVP_PKEY_encrypt(3)|EVP_PKEY_encrypt(3)>, |
+L<EVP_PKEY_decrypt(3)|EVP_PKEY_decrypt(3)>, |
+L<EVP_PKEY_sign(3)|EVP_PKEY_sign(3)>, |
+L<EVP_PKEY_verifyrecover(3)|EVP_PKEY_verifyrecover(3)>, |
+L<EVP_PKEY_derive(3)|EVP_PKEY_derive(3)> |
+ |
+=head1 HISTORY |
+ |
+These functions were first added to OpenSSL 1.0.0. |
+ |
+=cut |