Processes a PKCS #7 SignedData message.

Parameters

option_flag

Specifies process options to customize process behavior.

• Enforce signing certificate has digital signing capabilities. That is, the purpose of the certificate key as reflected by the key usage extension must indicate digitalSignature.
• Do not allow zero-length content data.

local_certificates

Specifies zero or more X.509 certificates to use when verifying the message signatures. NULL can be specified for this parameter if no local certificates are provided.

stream

Specifies the ASN.1 DER-encoded stream to be processed.

used_local

This parameter is set to TRUE if the signatures were verified by using just the certificates that are supplied by the local_certificates parameter. This parameter is set to FALSE if any of the signatures were verified by using certificates that are contained within the message.

msg_certificates

Returns the X.509 certificates that are contained within the message. The application should call the gsk_free_certificates() routine to release the certificates when they are no longer needed. Specify NULL for this parameter if the message certificates are not needed.

signer_certificates

Returns the certificates that are used to sign the message. The application should call the gsk_free_certificates() routine to release the certificates when they are no longer needed. Specify NULL for this parameter if the signer certificates are not needed.

attributes_signers

Returns the authenticated attributes per signer that is contained within the message. The application should call the gsk_free_attributes_signers() routine to release the gsk_attributes_signers structure when it is no longer needed. Specify NULL for this parameter if the authenticated attributes per signer are not needed. The set of authenticated attributes returned, omits the content-type and message-digest authenticated attributes as these authenticated attributes must always be present, if any authenticated attributes are present, and are automatically verified by gsk_read_signed_data_msg_extended(). The digestAlgorithm field within each gsk_attributes_signer structure returns the digest algorithm that is originally used for the signer.

data

Returns the content of the SignedData message. The application should call the gsk_free_buffer() routine to release the data when it is no longer needed.

Results

The function return value will be 0 if no error is detected. Otherwise, it is one of the return codes listed in the gskcms.h include file. These are some possible errors:

[ASN_NO_MEMORY]

Insufficient storage is available.

[ASN_SELECTION_OUT_OF_RANGE]

Certificate type or version number is not valid.

[CMSERR_ALG_NOT_SUPPORTED]

The digest algorithm is not supported.

[CMSERR_CONTENT_NOT_SUPPORTED]

The message content type is not SignedData or the content of the SignedData message is not Data.

[CMSERR_BAD_SIGNATURE]

Signature is not correct.

[CMSERR_DIGEST_KEY_MISMATCH]

The digest algorithm is not supported for the private key type.

[CMSERR_ECURVE_NOT_FIPS_APPROVED]

Elliptic Curve not supported in FIPS mode.

[CMSERR_ECURVE_NOT_SUPPORTED]

Elliptic Curve is not supported.

[CMSERR_ICSF_FIPS_DISABLED]

ICSF PKCS #11 services are disabled.

[CMSERR_ICSF_NOT_AVAILABLE]

ICSF services are not available.

[CMSERR_ICSF_NOT_FIPS]

ICSF PKCS #11 not operating in FIPS mode.

[CMSERR_ICSF_SERVICE_FAILURE]

ICSF callable service returned an error.

[CMSERR_INCORRECT_KEY_USAGE]

A signer certificate does not allow digital signature.

[CMSERR_NO_CONTENT_DATA]

The content data length is zero.

[CMSERR_NO_MEMORY]

Insufficient storage is available.

[CMSERR_SIGNER_NOT_FOUND]

Signer certificate not found.

Usage

The gsk_read_signed_data_msg_extended() routine processes a PKCS #7 (Cryptographic Message Syntax) SignedData message that is created by the gsk_make_signed_data_msg_extended() routine and returns the message content and all authenticated attributes (if present). The signed data content type must be Data.

Calling the gsk_read_signed_data_msg_extended() routine is equivalent to calling the gsk_read_content_msg() routine, the gsk_read_signed_data_content_extended() routine, and the gsk_read_data_content() routine.

The local_certificates parameter can supply the signer certificates that are used to verify the message signatures. If a certificate is not found for a message signer, the gsk_read_signed_data_msg_extended() routine attempts to locate the signer certificate in the SignedData message. An error is returned if the signer certificate cannot be found. An error may optionally be returned if the certificate key usage does not allow digital signature.

No certificate validation is performed by the gsk_read_signed_data_msg_extended() routine. It is assumed that the application validated the local certificates. The certificates that are contained in the SignedData message are returned in the msg_certificates parameter and the used_local parameter is set to FALSE if any of these certificates were used to verify the message signatures. It is the responsibility of the application to validate the message certificates (for example, by calling the gsk_validate_certificate_mode() routine for each of the signer certificates).

If authenticated attributes are returned from the attributes_signers parameter, then it is recommended that signing certificates for all signers represented within the gsk_attributes_signers structure should be requested from the signer_certificates parameter.

When executing in FIPS mode, digest algorithms x509_alg_md2Digest and x509_alg_md5Digest are not supported.