EVP_PKEY_sign.3 revision 267258
Automatically generated by Pod::Man 2.25 (Pod::Simple 3.28)

Standard preamble:
========================================================================
..
..
.. Set up some character translations and predefined strings. \*(-- will
give an unbreakable dash, \*(PI will give pi, \*(L" will give a left
double quote, and \*(R" will give a right double quote. \*(C+ will
give a nicer C++. Capital omega is used to do unbreakable dashes and
therefore won't be available. \*(C` and \*(C' expand to `' in nroff,
nothing in troff, for use with C<>.
.tr \(*W- . ds -- \(*W- . ds PI pi . if (\n(.H=4u)&(1m=24u) .ds -- \(*W\h'-12u'\(*W\h'-12u'-\" diablo 10 pitch . if (\n(.H=4u)&(1m=20u) .ds -- \(*W\h'-12u'\(*W\h'-8u'-\" diablo 12 pitch . ds L" "" . ds R" "" . ds C` "" . ds C' "" 'br\} . ds -- \|\(em\| . ds PI \(*p . ds L" `` . ds R" '' 'br\}
Escape single quotes in literal strings from groff's Unicode transform.

If the F register is turned on, we'll generate index entries on stderr for
titles (.TH), headers (.SH), subsections (.SS), items (.Ip), and index
entries marked with X<> in POD. Of course, you'll have to process the
output yourself in some meaningful fashion.
. de IX . tm Index:\\$1\t\\n%\t"\\$2" .. . nr % 0 . rr F .\} . de IX .. .\}
Accent mark definitions (@(#)ms.acc 1.5 88/02/08 SMI; from UCB 4.2).
Fear. Run. Save yourself. No user-serviceable parts.
. \" fudge factors for nroff and troff . ds #H 0 . ds #V .8m . ds #F .3m . ds #[ \f1 . ds #] .\} . ds #H ((1u-(\\\\n(.fu%2u))*.13m) . ds #V .6m . ds #F 0 . ds #[ \& . ds #] \& .\} . \" simple accents for nroff and troff . ds ' \& . ds ` \& . ds ^ \& . ds , \& . ds ~ ~ . ds / .\} . ds ' \\k:\h'-(\\n(.wu*8/10-\*(#H)'\'\h"|\\n:u" . ds ` \\k:\h'-(\\n(.wu*8/10-\*(#H)'\`\h'|\\n:u' . ds ^ \\k:\h'-(\\n(.wu*10/11-\*(#H)'^\h'|\\n:u' . ds , \\k:\h'-(\\n(.wu*8/10)',\h'|\\n:u' . ds ~ \\k:\h'-(\\n(.wu-\*(#H-.1m)'~\h'|\\n:u' . ds / \\k:\h'-(\\n(.wu*8/10-\*(#H)'\z\(sl\h'|\\n:u' .\} . \" troff and (daisy-wheel) nroff accents . \" corrections for vroff . \" for low resolution devices (crt and lpr) \{\ . ds : e . ds 8 ss . ds o a . ds d- d\h'-1'\(ga . ds D- D\h'-1'\(hy . ds th \o'bp' . ds Th \o'LP' . ds ae ae . ds Ae AE .\} ========================================================================

Title "EVP_PKEY_sign 3"
EVP_PKEY_sign 3 "2014-06-05" "1.0.1h" "OpenSSL"
For nroff, turn off justification. Always turn off hyphenation; it makes
way too many mistakes in technical documents.
"NAME"
EVP_PKEY_sign_init, EVP_PKEY_sign - sign using a public key algorithm
"SYNOPSIS"
Header "SYNOPSIS" .Vb 1 #include <openssl/evp.h> \& int EVP_PKEY_sign_init(EVP_PKEY_CTX *ctx); int EVP_PKEY_sign(EVP_PKEY_CTX *ctx, unsigned char *sig, size_t *siglen, const unsigned char *tbs, size_t tbslen); .Ve
"DESCRIPTION"
Header "DESCRIPTION" The EVP_PKEY_sign_init() function initializes a public key algorithm context using key pkey for a signing operation.

The EVP_PKEY_sign() function performs a public key signing operation using ctx. The data to be signed is specified using the tbs and \fBtbslen parameters. If sig is \s-1NULL\s0 then the maximum size of the output buffer is written to the siglen parameter. If sig is not \s-1NULL\s0 then before the call the siglen parameter should contain the length of the \fBsig buffer, if the call is successful the signature is written to \fBsig and the amount of data written to siglen.

"NOTES"
Header "NOTES" After the call to EVP_PKEY_sign_init() algorithm specific control operations can be performed to set any appropriate parameters for the operation.

The function EVP_PKEY_sign() can be called more than once on the same context if several operations are performed using the same parameters.

"RETURN VALUES"
Header "RETURN VALUES" \fIEVP_PKEY_sign_init() and EVP_PKEY_sign() return 1 for success and 0 or a negative value for failure. In particular a return value of -2 indicates the operation is not supported by the public key algorithm.
"EXAMPLE"
Header "EXAMPLE" Sign data using \s-1RSA\s0 with PKCS#1 padding and \s-1SHA256\s0 digest:

.Vb 2 #include <openssl/evp.h> #include <openssl/rsa.h> \& EVP_PKEY_CTX *ctx; unsigned char *md, *sig; size_t mdlen, siglen; EVP_PKEY *signing_key; /* NB: assumes signing_key, md and mdlen are already set up * and that signing_key is an RSA private key */ ctx = EVP_PKEY_CTX_new(signing_key); if (!ctx) /* Error occurred */ if (EVP_PKEY_sign_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 */ \& /* Determine buffer length */ if (EVP_PKEY_sign(ctx, NULL, &siglen, md, mdlen) <= 0) /* Error */ \& sig = OPENSSL_malloc(siglen); \& if (!sig) /* malloc failure */ if (EVP_PKEY_sign(ctx, sig, &siglen, md, mdlen) <= 0) /* Error */ \& /* Signature is siglen bytes written to buffer sig */ .Ve

"SEE ALSO"
Header "SEE ALSO" \fIEVP_PKEY_CTX_new\|(3), \fIEVP_PKEY_encrypt\|(3), \fIEVP_PKEY_decrypt\|(3), \fIEVP_PKEY_verify\|(3), \fIEVP_PKEY_verify_recover\|(3), \fIEVP_PKEY_derive\|(3)
"HISTORY"
Header "HISTORY" These functions were first added to OpenSSL 1.0.0.