From 60d59582dc15b87539a8dc135d2baf8a181ff37b Mon Sep 17 00:00:00 2001 From: schwarze <> Date: Thu, 3 Nov 2016 15:20:36 +0000 Subject: convert PEM and PKCS manuals from pod to mdoc --- src/lib/libcrypto/man/PKCS7_verify.3 | 193 +++++++++++++++++++++++++++++++++++ 1 file changed, 193 insertions(+) create mode 100644 src/lib/libcrypto/man/PKCS7_verify.3 (limited to 'src/lib/libcrypto/man/PKCS7_verify.3') diff --git a/src/lib/libcrypto/man/PKCS7_verify.3 b/src/lib/libcrypto/man/PKCS7_verify.3 new file mode 100644 index 0000000000..3cc6cbac66 --- /dev/null +++ b/src/lib/libcrypto/man/PKCS7_verify.3 @@ -0,0 +1,193 @@ +.Dd $Mdocdate: November 3 2016 $ +.Dt PKCS7_VERIFY 3 +.Os +.Sh NAME +.Nm PKCS7_verify , +.Nm PKCS7_get0_signers +.Nd verify a PKCS#7 signedData structure +.Sh SYNOPSIS +.In openssl/pkcs7.h +.Ft int +.Fo PKCS7_verify +.Fa "PKCS7 *p7" +.Fa "STACK_OF(X509) *certs" +.Fa "X509_STORE *store" +.Fa "BIO *indata" +.Fa "BIO *out" +.Fa "int flags" +.Fc +.Ft STACK_OF(X509) * +.Fo PKCS7_get0_signers +.Fa "PKCS7 *p7" +.Fa "STACK_OF(X509) *certs" +.Fa "int flags" +.Fc +.Sh DESCRIPTION +.Fn PKCS7_verify +verifies a PKCS#7 signedData structure. +.Fa p7 +is the +.Vt PKCS7 +structure to verify. +.Fa certs +is a set of certificates in which to search for the signer's +certificate. +.Fa store +is a trusted certificate store (used for chain verification). +.Fa indata +is the signed data if the content is not present in +.Fa p7 , +that is if it is detached. +The content is written to +.Fa out +if it is not +.Dv NULL . +.Pp +.Fa flags +is an optional set of flags, which can be used to modify the verify +operation. +.Pp +.Fn PKCS7_get0_signers +retrieves the signer's certificates from +.Fa p7 . +It does +.Sy not +check their validity or whether any signatures are valid. +The +.Fa certs +and +.Fa flags +parameters have the same meanings as in +.Fn PKCS7_verify . +.Pp +Normally the verify process proceeds as follows. +.Pp +Initially some sanity checks are performed on +.Fa p7 . +The type of +.Fa p7 +must be signedData. +There must be at least one signature on the data and if the content +is detached, +.Fa indata +cannot be +.Dv NULL . +.Pp +An attempt is made to locate all the signer's certificates, first +looking in the +.Fa certs +parameter (if it is not +.Dv NULL ) +and then looking in any certificates contained in the +.Fa p7 +structure itself. +If any signer's certificates cannot be located the operation fails. +.Pp +Each signer's certificate is chain verified using the +.Sy smimesign +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. +.Pp +Finally, the signed content is read (and written to +.Fa out +is it is not +.Dv NULL ) +and the signature's checked. +.Pp +If all signature's verify correctly then the function is successful. +.Pp +Any of the following flags (OR'ed together) can be passed in the +.Fa flags +parameter to change the default verify behaviour. +Only the flag +.Dv PKCS7_NOINTERN +is meaningful to +.Fn PKCS7_get0_signers . +.Pp +If +.Dv PKCS7_NOINTERN +is set, the certificates in the message itself are not searched when +locating the signer's certificate. +This means that all the signer's certificates must be in the +.Fa certs +parameter. +.Pp +If the +.Dv PKCS7_TEXT +flag is set, MIME headers for type +.Sy text/plain +are deleted from the content. +If the content is not of type +.Sy text/plain , +then an error is returned. +.Pp +If +.Dv PKCS7_NOVERIFY +is set, the signer's certificates are not chain verified. +.Pp +If +.Dv PKCS7_NOCHAIN +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. +.Pp +If +.Dv PKCS7_NOSIGS +is set, then the signatures on the data are not checked. +.Pp +One application of +.Dv PKCS7_NOINTERN +is to only accept messages signed by a small number of certificates. +The acceptable certificates would be passed in the +.Fa certs +parameter. +In this case, if the signer is not one of the certificates supplied in +.Fa certs , +then the verify will fail because the signer cannot be found. +.Pp +Care should be taken when modifying the default verify behaviour, for +example setting +.Dv PKCS7_NOVERIFY | PKCS7_NOSIGS +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 +.Fa out +and its validity is not considered important. +.Pp +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). +.Sh RETURN VALUES +.Fn PKCS7_verify +returns 1 for a successful verification and 0 or a negative value if +an error occurs. +.Pp +.Fn PKCS7_get0_signers +returns all signers or +.Dv NULL +if an error occurred. +.Pp +The error can be obtained from +.Xr ERR_get_error 3 . +.Sh SEE ALSO +.Xr ERR_get_error 3 , +.Xr PKCS7_sign 3 +.Sh HISTORY +.Fn PKCS7_verify +was added to OpenSSL 0.9.5 . +.Sh BUGS +The trusted certificate store is not searched for the signer's +certificate. +This is primarily due to the inadequacies of the current +.Vt X509_STORE +functionality. +.Pp +The lack of single pass processing and the need to hold all data +in memory as mentioned in +.Xr PKCS7_sign 3 +also applies to +.Fn PKCS7_verify . -- cgit v1.2.3-55-g6feb