pkey.encrypt() using EVP_PKEY_encrypt.

coro/ssl/openssl.pxi

@@ -153,6 +153,13 @@ cdef extern from "openssl/evp.h":
     int  EVP_SignFinal                 (EVP_MD_CTX *, char *, int *, EVP_PKEY *)
     int  EVP_VerifyFinal               (EVP_MD_CTX *, char *, int, EVP_PKEY *)
     int EVP_MAX_MD_SIZE
+    # --- public key encryption ---
+    ctypedef struct EVP_PKEY_CTX
+    # NOTE: replacing ENGINE * with void * here, we otherwise have no support for ENGINE.
+    EVP_PKEY_CTX * EVP_PKEY_CTX_new (EVP_PKEY *, void *)
+    void EVP_PKEY_CTX_free (EVP_PKEY_CTX *)
+    int  EVP_PKEY_encrypt_init         (EVP_PKEY_CTX *)
+    int  EVP_PKEY_encrypt              (EVP_PKEY_CTX *, unsigned char *, size_t *, const unsigned char *, size_t)
 
 cdef extern from "openssl/ec.h":
     ctypedef struct EC_KEY

coro/ssl/openssl.pyx

@@ -188,6 +188,29 @@ cdef class pkey:
     def bits (self):
         return self._bits()
 
+    def encrypt (self, bytes iblock):
+        cdef size_t outlen = 0
+        cdef bytes oblock
+        # NOTE: no engine support yet...
+        cdef EVP_PKEY_CTX * ctx = EVP_PKEY_CTX_new (self.pkey, NULL)
+        if ctx is NULL:
+            raise_ssl_error()
+        else:
+            try:
+                if EVP_PKEY_encrypt_init (ctx) != 1:
+                    raise_ssl_error()
+                else:
+                    if EVP_PKEY_encrypt (ctx, NULL, &outlen, iblock, len(iblock)) != 1:
+                        raise_ssl_error()
+                    else:
+                        oblock = PyBytes_FromStringAndSize (NULL, outlen)
+                        if EVP_PKEY_encrypt (ctx, oblock, &outlen, iblock, len(iblock)) != 1:
+                            raise_ssl_error()
+                        else:
+                            return oblock
+            finally:
+                EVP_PKEY_CTX_free (ctx)
+
 # compatibility
 def read_pem_key (pem, pwd):
     return pkey (pem, pwd, True)