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| author | cvs2svn <admin@example.com> | 2016-07-23 19:31:36 +0000 |
|---|---|---|
| committer | cvs2svn <admin@example.com> | 2016-07-23 19:31:36 +0000 |
| commit | 26ff9ecbb759894e0a2062db162a61a94b3374d2 (patch) | |
| tree | e9a354a92a348338fe2b361e2eda703cae23cfab /src/lib/libcrypto/doc/EVP_SignInit.pod | |
| parent | cd24674739573c5e6cb697331fb638ea66897f3d (diff) | |
| download | openbsd-OPENBSD_6_0_BASE.tar.gz openbsd-OPENBSD_6_0_BASE.tar.bz2 openbsd-OPENBSD_6_0_BASE.zip | |
This commit was manufactured by cvs2git to create tag 'OPENBSD_6_0_BASE'.OPENBSD_6_0_BASE
Diffstat (limited to 'src/lib/libcrypto/doc/EVP_SignInit.pod')
| -rw-r--r-- | src/lib/libcrypto/doc/EVP_SignInit.pod | 103 |
1 files changed, 0 insertions, 103 deletions
diff --git a/src/lib/libcrypto/doc/EVP_SignInit.pod b/src/lib/libcrypto/doc/EVP_SignInit.pod deleted file mode 100644 index 6882211e02..0000000000 --- a/src/lib/libcrypto/doc/EVP_SignInit.pod +++ /dev/null | |||
| @@ -1,103 +0,0 @@ | |||
| 1 | =pod | ||
| 2 | |||
| 3 | =head1 NAME | ||
| 4 | |||
| 5 | EVP_SignInit, EVP_SignUpdate, EVP_SignFinal, EVP_PKEY_size | ||
| 6 | - EVP signing functions | ||
| 7 | |||
| 8 | =head1 SYNOPSIS | ||
| 9 | |||
| 10 | #include <openssl/evp.h> | ||
| 11 | |||
| 12 | int EVP_SignInit_ex(EVP_MD_CTX *ctx, const EVP_MD *type, ENGINE *impl); | ||
| 13 | int EVP_SignUpdate(EVP_MD_CTX *ctx, const void *d, unsigned int cnt); | ||
| 14 | int EVP_SignFinal(EVP_MD_CTX *ctx,unsigned char *sig,unsigned int *s, EVP_PKEY *pkey); | ||
| 15 | |||
| 16 | void EVP_SignInit(EVP_MD_CTX *ctx, const EVP_MD *type); | ||
| 17 | |||
| 18 | int EVP_PKEY_size(EVP_PKEY *pkey); | ||
| 19 | |||
| 20 | =head1 DESCRIPTION | ||
| 21 | |||
| 22 | The EVP signature routines are a high level interface to digital | ||
| 23 | signatures. | ||
| 24 | |||
| 25 | EVP_SignInit_ex() sets up signing context B<ctx> to use digest | ||
| 26 | B<type> from ENGINE B<impl>. B<ctx> must be initialized with | ||
| 27 | EVP_MD_CTX_init() before calling this function. | ||
| 28 | |||
| 29 | EVP_SignUpdate() hashes B<cnt> bytes of data at B<d> into the | ||
| 30 | signature context B<ctx>. This function can be called several times on the | ||
| 31 | same B<ctx> to include additional data. | ||
| 32 | |||
| 33 | EVP_SignFinal() signs the data in B<ctx> using the private key B<pkey> and | ||
| 34 | places the signature in B<sig>. B<sig> must be at least EVP_PKEY_size(pkey) | ||
| 35 | bytes in size. B<s> is an OUT parameter, and not used as an IN parameter. | ||
| 36 | The number of bytes of data written (i.e. the length of the signature) | ||
| 37 | will be written to the integer at B<s>, at most EVP_PKEY_size(pkey) bytes | ||
| 38 | will be written. | ||
| 39 | |||
| 40 | EVP_SignInit() initializes a signing context B<ctx> to use the default | ||
| 41 | implementation of digest B<type>. | ||
| 42 | |||
| 43 | EVP_PKEY_size() returns the maximum size of a signature in bytes. The actual | ||
| 44 | signature returned by EVP_SignFinal() may be smaller. | ||
| 45 | |||
| 46 | =head1 RETURN VALUES | ||
| 47 | |||
| 48 | EVP_SignInit_ex(), EVP_SignUpdate() and EVP_SignFinal() return 1 | ||
| 49 | for success and 0 for failure. | ||
| 50 | |||
| 51 | EVP_PKEY_size() returns the maximum size of a signature in bytes. | ||
| 52 | |||
| 53 | The error codes can be obtained by L<ERR_get_error(3)|ERR_get_error(3)>. | ||
| 54 | |||
| 55 | =head1 NOTES | ||
| 56 | |||
| 57 | The B<EVP> interface to digital signatures should almost always be used in | ||
| 58 | preference to the low level interfaces. This is because the code then becomes | ||
| 59 | transparent to the algorithm used and much more flexible. | ||
| 60 | |||
| 61 | Due to the link between message digests and public key algorithms the correct | ||
| 62 | digest algorithm must be used with the correct public key type. A list of | ||
| 63 | algorithms and associated public key algorithms appears in | ||
| 64 | L<EVP_DigestInit(3)|EVP_DigestInit(3)>. | ||
| 65 | |||
| 66 | The call to EVP_SignFinal() internally finalizes a copy of the digest context. | ||
| 67 | This means that calls to EVP_SignUpdate() and EVP_SignFinal() can be called | ||
| 68 | later to digest and sign additional data. | ||
| 69 | |||
| 70 | Since only a copy of the digest context is ever finalized the context must | ||
| 71 | be cleaned up after use by calling EVP_MD_CTX_cleanup() or a memory leak | ||
| 72 | will occur. | ||
| 73 | |||
| 74 | =head1 BUGS | ||
| 75 | |||
| 76 | Older versions of this documentation wrongly stated that calls to | ||
| 77 | EVP_SignUpdate() could not be made after calling EVP_SignFinal(). | ||
| 78 | |||
| 79 | Since the private key is passed in the call to EVP_SignFinal() any error | ||
| 80 | relating to the private key (for example an unsuitable key and digest | ||
| 81 | combination) will not be indicated until after potentially large amounts of | ||
| 82 | data have been passed through EVP_SignUpdate(). | ||
| 83 | |||
| 84 | It is not possible to change the signing parameters using these function. | ||
| 85 | |||
| 86 | The previous two bugs are fixed in the newer EVP_SignDigest*() function. | ||
| 87 | |||
| 88 | =head1 SEE ALSO | ||
| 89 | |||
| 90 | L<EVP_VerifyInit(3)|EVP_VerifyInit(3)>, | ||
| 91 | L<EVP_DigestInit(3)|EVP_DigestInit(3)>, L<err(3)|err(3)>, | ||
| 92 | L<evp(3)|evp(3)>, L<hmac(3)|hmac(3)>, L<md2(3)|md2(3)>, | ||
| 93 | L<md5(3)|md5(3)>, L<ripemd(3)|ripemd(3)>, | ||
| 94 | L<sha(3)|sha(3)>, L<dgst(1)|dgst(1)> | ||
| 95 | |||
| 96 | =head1 HISTORY | ||
| 97 | |||
| 98 | EVP_SignInit(), EVP_SignUpdate() and EVP_SignFinal() are | ||
| 99 | available in all versions of SSLeay and OpenSSL. | ||
| 100 | |||
| 101 | EVP_SignInit_ex() was added in OpenSSL 0.9.7. | ||
| 102 | |||
| 103 | =cut | ||
