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author | William Joye <wjoye@cfa.harvard.edu> | 2017-05-02 16:41:35 (GMT) |
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committer | William Joye <wjoye@cfa.harvard.edu> | 2017-05-02 16:41:35 (GMT) |
commit | 3d328008deedc58cd7a11c79063cefa7d662d4fc (patch) | |
tree | cb41a048885ce7b493f406360cf5f6edf689c468 /openssl/doc/crypto/EVP_PKEY_verify.pod | |
parent | 0a2b8b8e0bc2e91a9f10659b30e2e4f5b79ce692 (diff) | |
download | blt-3d328008deedc58cd7a11c79063cefa7d662d4fc.zip blt-3d328008deedc58cd7a11c79063cefa7d662d4fc.tar.gz blt-3d328008deedc58cd7a11c79063cefa7d662d4fc.tar.bz2 |
inital commit
Diffstat (limited to 'openssl/doc/crypto/EVP_PKEY_verify.pod')
-rw-r--r-- | openssl/doc/crypto/EVP_PKEY_verify.pod | 91 |
1 files changed, 91 insertions, 0 deletions
diff --git a/openssl/doc/crypto/EVP_PKEY_verify.pod b/openssl/doc/crypto/EVP_PKEY_verify.pod new file mode 100644 index 0000000..90612ba --- /dev/null +++ b/openssl/doc/crypto/EVP_PKEY_verify.pod @@ -0,0 +1,91 @@ +=pod + +=head1 NAME + +EVP_PKEY_verify_init, EVP_PKEY_verify - signature verification using a public key algorithm + +=head1 SYNOPSIS + + #include <openssl/evp.h> + + int EVP_PKEY_verify_init(EVP_PKEY_CTX *ctx); + int EVP_PKEY_verify(EVP_PKEY_CTX *ctx, + const unsigned char *sig, size_t siglen, + const unsigned char *tbs, size_t tbslen); + +=head1 DESCRIPTION + +The EVP_PKEY_verify_init() function initializes a public key algorithm +context using key B<pkey> for a signature verification operation. + +The EVP_PKEY_verify() function performs a public key verification operation +using B<ctx>. The signature is specified using the B<sig> and +B<siglen> parameters. The verified data (i.e. the data believed originally +signed) is specified using the B<tbs> and B<tbslen> parameters. + +=head1 NOTES + +After the call to EVP_PKEY_verify_init() algorithm specific control +operations can be performed to set any appropriate parameters for the +operation. + +The function EVP_PKEY_verify() can be called more than once on the same +context if several operations are performed using the same parameters. + +=head1 RETURN VALUES + +EVP_PKEY_verify_init() and EVP_PKEY_verify() return 1 if the verification was +successful and 0 if it failed. Unlike other functions the return value 0 from +EVP_PKEY_verify() only indicates that the signature did not not verify +successfully (that is tbs did not match the original data or the signature was +of invalid form) it is not an indication of a more serious error. + +A negative value indicates an error other that signature verification failure. +In particular a return value of -2 indicates the operation is not supported by +the public key algorithm. + +=head1 EXAMPLE + +Verify signature using PKCS#1 and SHA256 digest: + + #include <openssl/evp.h> + #include <openssl/rsa.h> + + EVP_PKEY_CTX *ctx; + unsigned char *md, *sig; + size_t mdlen, siglen; + EVP_PKEY *verify_key; + /* NB: assumes verify_key, sig, siglen md and mdlen are already set up + * and that verify_key is an RSA public key + */ + ctx = EVP_PKEY_CTX_new(verify_key); + if (!ctx) + /* Error occurred */ + if (EVP_PKEY_verify_init(ctx) <= 0) + /* Error */ + if (EVP_PKEY_CTX_set_rsa_padding(ctx, RSA_PKCS1_PADDING) <= 0) + /* Error */ + if (EVP_PKEY_CTX_set_signature_md(ctx, EVP_sha256()) <= 0) + /* Error */ + + /* Perform operation */ + ret = EVP_PKEY_verify(ctx, sig, siglen, md, mdlen); + + /* ret == 1 indicates success, 0 verify failure and < 0 for some + * other error. + */ + +=head1 SEE ALSO + +L<EVP_PKEY_CTX_new(3)|EVP_PKEY_CTX_new(3)>, +L<EVP_PKEY_encrypt(3)|EVP_PKEY_encrypt(3)>, +L<EVP_PKEY_decrypt(3)|EVP_PKEY_decrypt(3)>, +L<EVP_PKEY_sign(3)|EVP_PKEY_sign(3)>, +L<EVP_PKEY_verify_recover(3)|EVP_PKEY_verify_recover(3)>, +L<EVP_PKEY_derive(3)|EVP_PKEY_derive(3)> + +=head1 HISTORY + +These functions were first added to OpenSSL 1.0.0. + +=cut |