— Function: gpgme_error_t gpgme_op_decrypt (gpgme_ctx_t ctx, gpgme_data_t cipher, gpgme_data_t plain)

The function gpgme_op_decrypt decrypts the ciphertext in the data object cipher and stores it into the data object plain.

The function returns the error code GPG_ERR_NO_ERROR if the ciphertext could be decrypted successfully, GPG_ERR_INV_VALUE if ctx, cipher or plain is not a valid pointer, GPG_ERR_NO_DATA if cipher does not contain any data to decrypt, GPG_ERR_DECRYPT_FAILED if cipher is not a valid cipher text, GPG_ERR_BAD_PASSPHRASE if the passphrase for the secret key could not be retrieved, and passes through any errors that are reported by the crypto engine support routines.

— Function: gpgme_error_t gpgme_op_decrypt_start (gpgme_ctx_t ctx, gpgme_data_t cipher, gpgme_data_t plain)

The function gpgme_op_decrypt_start initiates a gpgme_op_decrypt operation. It can be completed by calling gpgme_wait on the context. See Waiting For Completion.

The function returns the error code GPG_ERR_NO_ERROR if the operation could be started successfully, and GPG_ERR_INV_VALUE if cipher or plain is not a valid pointer.

— Data type: gpgme_recipient_t

This is a pointer to a structure used to store information about the recipient of an encrypted text which is decrypted in a gpgme_op_decrypt operation. This information (except for the status field) is even available before the operation finished successfully, for example in a passphrase callback. The structure contains the following members:

gpgme_recipient_t next

This is a pointer to the next recipient structure in the linked list, or NULL if this is the last element.

gpgme_pubkey_algo_t

The public key algorithm used in the encryption.

unsigned int wrong_key_usage : 1

This is true if the key was not used according to its policy.

char *keyid

This is the key ID of the key (in hexadecimal digits) used as recipient.

gpgme_error_t status

This is an error number with the error code GPG_ERR_NO_SECKEY if the secret key for this recipient is not available, and 0 otherwise.

— Data type: gpgme_decrypt_result_t

This is a pointer to a structure used to store the result of a gpgme_op_decrypt operation. After successfully decrypting data, you can retrieve the pointer to the result with gpgme_op_decrypt_result. The structure contains the following members:

char *unsupported_algorithm

If an unsupported algorithm was encountered, this string describes the algorithm that is not supported.

unsigned int wrong_key_usage : 1

This is true if the key was not used according to its policy.

gpgme_recipient_t recipient

This is a linked list of recipients to which this message was encrypted.

char *file_name

This is the filename of the original plaintext message file if it is known, otherwise this is a null pointer.

— Function: gpgme_decrypt_result_t gpgme_op_decrypt_result (gpgme_ctx_t ctx)

The function gpgme_op_decrypt_result returns a gpgme_decrypt_result_t pointer to a structure holding the result of a gpgme_op_decrypt operation. The pointer is only valid if the last operation on the context was a gpgme_op_decrypt or gpgme_op_decrypt_start operation. If the operation failed this might be a NULL pointer. The returned pointer is only valid until the next operation is started on the context.