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Diffstat (limited to 'roms/edk2/CryptoPkg/Library/OpensslLib/openssl/doc/man3/EVP_VerifyInit.pod')
-rw-r--r-- | roms/edk2/CryptoPkg/Library/OpensslLib/openssl/doc/man3/EVP_VerifyInit.pod | 95 |
1 files changed, 95 insertions, 0 deletions
diff --git a/roms/edk2/CryptoPkg/Library/OpensslLib/openssl/doc/man3/EVP_VerifyInit.pod b/roms/edk2/CryptoPkg/Library/OpensslLib/openssl/doc/man3/EVP_VerifyInit.pod new file mode 100644 index 000000000..647c99bce --- /dev/null +++ b/roms/edk2/CryptoPkg/Library/OpensslLib/openssl/doc/man3/EVP_VerifyInit.pod @@ -0,0 +1,95 @@ +=pod + +=head1 NAME + +EVP_VerifyInit_ex, +EVP_VerifyInit, EVP_VerifyUpdate, EVP_VerifyFinal +- EVP signature verification functions + +=head1 SYNOPSIS + + #include <openssl/evp.h> + + int EVP_VerifyInit_ex(EVP_MD_CTX *ctx, const EVP_MD *type, ENGINE *impl); + int EVP_VerifyUpdate(EVP_MD_CTX *ctx, const void *d, unsigned int cnt); + int EVP_VerifyFinal(EVP_MD_CTX *ctx, unsigned char *sigbuf, unsigned int siglen, + EVP_PKEY *pkey); + + int EVP_VerifyInit(EVP_MD_CTX *ctx, const EVP_MD *type); + +=head1 DESCRIPTION + +The EVP signature verification routines are a high level interface to digital +signatures. + +EVP_VerifyInit_ex() sets up verification context B<ctx> to use digest +B<type> from ENGINE B<impl>. B<ctx> must be created by calling +EVP_MD_CTX_new() before calling this function. + +EVP_VerifyUpdate() hashes B<cnt> bytes of data at B<d> into the +verification context B<ctx>. This function can be called several times on the +same B<ctx> to include additional data. + +EVP_VerifyFinal() verifies the data in B<ctx> using the public key B<pkey> +and against the B<siglen> bytes at B<sigbuf>. + +EVP_VerifyInit() initializes verification context B<ctx> to use the default +implementation of digest B<type>. + +=head1 RETURN VALUES + +EVP_VerifyInit_ex() and EVP_VerifyUpdate() return 1 for success and 0 for +failure. + +EVP_VerifyFinal() returns 1 for a correct signature, 0 for failure and -1 if some +other error occurred. + +The error codes can be obtained by L<ERR_get_error(3)>. + +=head1 NOTES + +The B<EVP> interface to digital signatures should almost always be used in +preference to the low level interfaces. This is because the code then becomes +transparent to the algorithm used and much more flexible. + +The call to EVP_VerifyFinal() internally finalizes a copy of the digest context. +This means that calls to EVP_VerifyUpdate() and EVP_VerifyFinal() can be called +later to digest and verify additional data. + +Since only a copy of the digest context is ever finalized the context must +be cleaned up after use by calling EVP_MD_CTX_free() or a memory leak +will occur. + +=head1 BUGS + +Older versions of this documentation wrongly stated that calls to +EVP_VerifyUpdate() could not be made after calling EVP_VerifyFinal(). + +Since the public key is passed in the call to EVP_SignFinal() any error +relating to the private key (for example an unsuitable key and digest +combination) will not be indicated until after potentially large amounts of +data have been passed through EVP_SignUpdate(). + +It is not possible to change the signing parameters using these function. + +The previous two bugs are fixed in the newer EVP_DigestVerify*() function. + +=head1 SEE ALSO + +L<evp(7)>, +L<EVP_SignInit(3)>, +L<EVP_DigestInit(3)>, +L<evp(7)>, L<HMAC(3)>, L<MD2(3)>, +L<MD5(3)>, L<MDC2(3)>, L<RIPEMD160(3)>, +L<SHA1(3)>, L<dgst(1)> + +=head1 COPYRIGHT + +Copyright 2000-2019 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<https://www.openssl.org/source/license.html>. + +=cut |