EVP_DigestSignInit() sets up signing context B<ctx> to use digest B<type> from
ENGINE B<e> and private key B<pkey>. B<ctx> must be created with
-EVP_MD_CTX_new() before calling this function. If B<pctx> is not NULL the
+EVP_MD_CTX_new() before calling this function. If B<pctx> is not NULL, the
EVP_PKEY_CTX of the signing operation will be written to B<*pctx>: this can
-be used to set alternative signing options. The digest B<type> may be NULL if
-the signing algorithm supports it.
+be used to set alternative signing options. Note that any existing value in
+B<*pctx> is overwritten. The EVP_PKEY_CTX value returned must not be freed
+directly by the application (it will be freed automatically when the EVP_MD_CTX
+is freed). The digest B<type> may be NULL if the signing algorithm supports it.
Only EVP_PKEY types that support signing can be used with these functions. This
includes MAC algorithms where the MAC generation is considered as a form of
EVP_DigestVerifyInit() sets up verification context B<ctx> to use digest
B<type> from ENGINE B<e> and public key B<pkey>. B<ctx> must be created
-with EVP_MD_CTX_new() before calling this function. If B<pctx> is not NULL the
+with EVP_MD_CTX_new() before calling this function. If B<pctx> is not NULL, the
EVP_PKEY_CTX of the verification operation will be written to B<*pctx>: this
-can be used to set alternative verification options.
+can be used to set alternative verification options. Note that any existing
+value in B<*pctx> is overwritten. The EVP_PKEY_CTX value returned must not be
+freed directly by the application (it will be freed automatically when the
+EVP_MD_CTX is freed).
EVP_DigestVerifyUpdate() hashes B<cnt> bytes of data at B<d> into the
verification context B<ctx>. This function can be called several times on the