SERIALIZER: add support for serializing EVP_PKEYs

The following public functions is added:

- OSSL_SERIALIZER_CTX_new_by_EVP_PKEY()
- OSSL_SERIALIZER_CTX_set_cipher()
- OSSL_SERIALIZER_CTX_set_passphrase()
- OSSL_SERIALIZER_CTX_set_passphrase_cb()
- OSSL_SERIALIZER_CTX_set_passphrase_ui()

OSSL_SERIALIZER_CTX_new_by_EVP_PKEY() selects a suitable serializer
for the given EVP_PKEY, and sets up the OSSL_SERIALIZER_CTX to
function together with OSSL_SERIALIZER_to_bio() and
OSSL_SERIALIZER_to_fp().

OSSL_SERIALIZER_CTX_set_cipher() indicates what cipher should be used
to produce an encrypted serialization of the EVP_PKEY.  This is passed
directly to the provider using OSSL_SERIALIZER_CTX_set_params().

OSSL_SERIALIZER_CTX_set_passphrase() can be used to set a pass phrase
to be used for the encryption.  This is passed directly to the
provider using OSSL_SERIALIZER_CTX_set_params().

OSSL_SERIALIZER_CTX_set_passphrase_cb() and
OSSL_SERIALIZER_CTX_set_passphrase_ui() sets up a callback to be used
to prompt for a passphrase.  This is stored in the context, and is
called via an internal intermediary at the time of serialization.

Reviewed-by: Matt Caswell <matt@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/10394)

1 files changed, 1 insertions, 0 deletions

diff --git a/crypto/err/err.c b/crypto/err/err.c
index 0fb46bef4d..e77cfe83cf 100644
--- a/crypto/err/err.c
+++ b/crypto/err/err.c
@@ -113,6 +113,7 @@ static ERR_STRING_DATA ERR_str_reasons[] = {
     {ERR_R_INIT_FAIL, "init fail"},
     {ERR_R_OPERATION_FAIL, "operation fail"},
     {ERR_R_INVALID_PROVIDER_FUNCTIONS, "invalid provider functions"},
+    {ERR_R_INTERRUPTED_OR_CANCELLED, "interrupted or cancelled"},
 
     {0, NULL},
 };