File: gpgme.info,  Node: Error Codes,  Next: Error Strings,  Prev: Error Sources,  Up: Error Handling

5.3 Error Codes
===============

The library ‘libgpg-error’ defines many error values.  Most of them are
not used by ‘GPGME’ directly, but might be returned by GPGME because it
received them from the crypto engine.  The below list only includes such
error codes that have a specific meaning in ‘GPGME’, or which are so
common that you should know about them.

‘GPG_ERR_EOF’
     This value indicates the end of a list, buffer or file.

‘GPG_ERR_NO_ERROR’
     This value indicates success.  The value of this error code is ‘0’.
     Also, it is guaranteed that an error value made from the error code
     ‘0’ will be ‘0’ itself (as a whole).  This means that the error
     source information is lost for this error code, however, as this
     error code indicates that no error occurred, this is generally not
     a problem.

‘GPG_ERR_GENERAL’
     This value means that something went wrong, but either there is not
     enough information about the problem to return a more useful error
     value, or there is no separate error value for this type of
     problem.

‘GPG_ERR_ENOMEM’
     This value means that an out-of-memory condition occurred.

‘GPG_ERR_E...’
     System errors are mapped to GPG_ERR_FOO where FOO is the symbol for
     the system error.

‘GPG_ERR_INV_VALUE’
     This value means that some user provided data was out of range.
     This can also refer to objects.  For example, if an empty
     ‘gpgme_data_t’ object was expected, but one containing data was
     provided, this error value is returned.

‘GPG_ERR_UNUSABLE_PUBKEY’
     This value means that some recipients for a message were invalid.

‘GPG_ERR_UNUSABLE_SECKEY’
     This value means that some signers were invalid.

‘GPG_ERR_NO_DATA’
     This value means that a ‘gpgme_data_t’ object which was expected to
     have content was found empty.

‘GPG_ERR_CONFLICT’
     This value means that a conflict of some sort occurred.

‘GPG_ERR_NOT_IMPLEMENTED’
     This value indicates that the specific function (or operation) is
     not implemented.  This error should never happen.  It can only
     occur if you use certain values or configuration options which do
     not work, but for which we think that they should work at some
     later time.

‘GPG_ERR_DECRYPT_FAILED’
     This value indicates that a decryption operation was unsuccessful.

‘GPG_ERR_BAD_PASSPHRASE’
     This value means that the user did not provide a correct passphrase
     when requested.

‘GPG_ERR_CANCELED’
     This value means that the operation was canceled.

‘GPG_ERR_FULLY_CANCELED’
     This value means that the operation was canceled.  It is sometimes
     returned instead of ‘GPG_ERR_CANCELED’ for internal reasons in
     GnuPG. You should treat both values identically.

‘GPG_ERR_INV_ENGINE’
     This value means that the engine that implements the desired
     protocol is currently not available.  This can either be because
     the sources were configured to exclude support for this engine, or
     because the engine is not installed properly.

‘GPG_ERR_AMBIGUOUS_NAME’
     This value indicates that a user ID or other specifier did not
     specify a unique key.

‘GPG_ERR_WRONG_KEY_USAGE’
     This value indicates that a key is not used appropriately.

‘GPG_ERR_CERT_REVOKED’
     This value indicates that a key signature was revoced.

‘GPG_ERR_CERT_EXPIRED’
     This value indicates that a key signature expired.

‘GPG_ERR_NO_CRL_KNOWN’
     This value indicates that no certificate revocation list is known
     for the certificate.

‘GPG_ERR_NO_POLICY_MATCH’
     This value indicates that a policy issue occurred.

‘GPG_ERR_NO_SECKEY’
     This value indicates that no secret key for the user ID is
     available.

‘GPG_ERR_MISSING_CERT’
     This value indicates that a key could not be imported because the
     issuer certificate is missing.

‘GPG_ERR_BAD_CERT_CHAIN’
     This value indicates that a key could not be imported because its
     certificate chain is not good, for example it could be too long.

‘GPG_ERR_UNSUPPORTED_ALGORITHM’
     This value means a verification failed because the cryptographic
     algorithm is not supported by the crypto backend.

‘GPG_ERR_BAD_SIGNATURE’
     This value means a verification failed because the signature is
     bad.

‘GPG_ERR_NO_PUBKEY’
     This value means a verification failed because the public key is
     not available.

‘GPG_ERR_USER_1’
‘GPG_ERR_USER_2’
‘...’
‘GPG_ERR_USER_16’
     These error codes are not used by any GnuPG component and can be
     freely used by other software.  Applications using GPGME might use
     them to mark specific errors returned by callback handlers if no
     suitable error codes (including the system errors) for these errors
     exist already.