From aa4d426b4d3527d7e166df1a05058c9a4a0f6683 Mon Sep 17 00:00:00 2001 From: Wojtek Kosior Date: Fri, 30 Apr 2021 00:33:56 +0200 Subject: initial/final commit --- openssl-1.1.0h/doc/crypto/PKCS7_verify.pod | 128 +++++++++++++++++++++++++++++ 1 file changed, 128 insertions(+) create mode 100644 openssl-1.1.0h/doc/crypto/PKCS7_verify.pod (limited to 'openssl-1.1.0h/doc/crypto/PKCS7_verify.pod') diff --git a/openssl-1.1.0h/doc/crypto/PKCS7_verify.pod b/openssl-1.1.0h/doc/crypto/PKCS7_verify.pod new file mode 100644 index 0000000..c34808e --- /dev/null +++ b/openssl-1.1.0h/doc/crypto/PKCS7_verify.pod @@ -0,0 +1,128 @@ +=pod + +=head1 NAME + +PKCS7_verify, PKCS7_get0_signers - verify a PKCS#7 signedData structure + +=head1 SYNOPSIS + + #include + + int PKCS7_verify(PKCS7 *p7, STACK_OF(X509) *certs, X509_STORE *store, BIO *indata, BIO *out, int flags); + + STACK_OF(X509) *PKCS7_get0_signers(PKCS7 *p7, STACK_OF(X509) *certs, int flags); + +=head1 DESCRIPTION + +PKCS7_verify() verifies a PKCS#7 signedData structure. B is the PKCS7 +structure to verify. B is a set of certificates in which to search for +the signer's certificate. B is a trusted certificate store (used for +chain verification). B is the signed data if the content is not +present in B (that is it is detached). The content is written to B +if it is not NULL. + +B is an optional set of flags, which can be used to modify the verify +operation. + +PKCS7_get0_signers() retrieves the signer's certificates from B, it does +B check their validity or whether any signatures are valid. The B +and B parameters have the same meanings as in PKCS7_verify(). + +=head1 VERIFY PROCESS + +Normally the verify process proceeds as follows. + +Initially some sanity checks are performed on B. The type of B must +be signedData. There must be at least one signature on the data and if +the content is detached B cannot be B. If the content is +not detached and B is not B, then the structure has both +embedded and external content. To treat this as an error, use the flag +B. +The default behavior allows this, for compatibility with older +versions of OpenSSL. + +An attempt is made to locate all the signer's certificates, first looking in +the B parameter (if it is not B) and then looking in any certificates +contained in the B structure itself. If any signer's certificates cannot be +located the operation fails. + +Each signer's certificate is chain verified using the B purpose and +the supplied trusted certificate store. Any internal certificates in the message +are used as untrusted CAs. If any chain verify fails an error code is returned. + +Finally the signed content is read (and written to B is it is not NULL) and +the signature's checked. + +If all signature's verify correctly then the function is successful. + +Any of the following flags (ored together) can be passed in the B parameter +to change the default verify behaviour. Only the flag B is +meaningful to PKCS7_get0_signers(). + +If B is set the certificates in the message itself are not +searched when locating the signer's certificate. This means that all the signers +certificates must be in the B parameter. + +If the B flag is set MIME headers for type B are deleted +from the content. If the content is not of type B then an error is +returned. + +If B is set the signer's certificates are not chain verified. + +If B is set then the certificates contained in the message are +not used as untrusted CAs. This means that the whole verify chain (apart from +the signer's certificate) must be contained in the trusted store. + +If B is set then the signatures on the data are not checked. + +=head1 NOTES + +One application of B is to only accept messages signed by +a small number of certificates. The acceptable certificates would be passed +in the B parameter. In this case if the signer is not one of the +certificates supplied in B then the verify will fail because the +signer cannot be found. + +Care should be taken when modifying the default verify behaviour, for example +setting B will totally disable all verification +and any signed message will be considered valid. This combination is however +useful if one merely wishes to write the content to B and its validity +is not considered important. + +Chain verification should arguably be performed using the signing time rather +than the current time. However since the signing time is supplied by the +signer it cannot be trusted without additional evidence (such as a trusted +timestamp). + +=head1 RETURN VALUES + +PKCS7_verify() returns one for a successful verification and zero +if an error occurs. + +PKCS7_get0_signers() returns all signers or B if an error occurred. + +The error can be obtained from L + +=head1 BUGS + +The trusted certificate store is not searched for the signers certificate, +this is primarily due to the inadequacies of the current B +functionality. + +The lack of single pass processing and need to hold all data in memory as +mentioned in PKCS7_sign() also applies to PKCS7_verify(). + +=head1 SEE ALSO + +L, L + +=head1 COPYRIGHT + +Copyright 2002-2016 The OpenSSL Project Authors. All Rights Reserved. + +Licensed under the OpenSSL license (the "License"). You may not use +this file except in compliance with the License. You can obtain a copy +in the file LICENSE in the source distribution or at +L. + +=cut -- cgit v1.2.3