1 .\" Automatically generated by Pod::Man 4.07 (Pod::Simple 3.35)
4 .\" ========================================================================
5 .de Sp \" Vertical space (when we can't use .PP)
9 .de Vb \" Begin verbatim text
14 .de Ve \" End verbatim text
18 .\" Set up some character translations and predefined strings. \*(-- will
19 .\" give an unbreakable dash, \*(PI will give pi, \*(L" will give a left
20 .\" double quote, and \*(R" will give a right double quote. \*(C+ will
21 .\" give a nicer C++. Capital omega is used to do unbreakable dashes and
22 .\" therefore won't be available. \*(C` and \*(C' expand to `' in nroff,
23 .\" nothing in troff, for use with C<>.
25 .ds C+ C\v'-.1v'\h'-1p'\s-2+\h'-1p'+\s0\v'.1v'\h'-1p'
29 . if (\n(.H=4u)&(1m=24u) .ds -- \(*W\h'-12u'\(*W\h'-12u'-\" diablo 10 pitch
30 . if (\n(.H=4u)&(1m=20u) .ds -- \(*W\h'-12u'\(*W\h'-8u'-\" diablo 12 pitch
45 .\" Escape single quotes in literal strings from groff's Unicode transform.
49 .\" If the F register is >0, we'll generate index entries on stderr for
50 .\" titles (.TH), headers (.SH), subsections (.SS), items (.Ip), and index
51 .\" entries marked with X<> in POD. Of course, you'll have to process the
52 .\" output yourself in some meaningful fashion.
54 .\" Avoid warning from groff about undefined register 'F'.
60 . tm Index:\\$1\t\\n%\t"\\$2"
68 .\" Accent mark definitions (@(#)ms.acc 1.5 88/02/08 SMI; from UCB 4.2).
69 .\" Fear. Run. Save yourself. No user-serviceable parts.
70 . \" fudge factors for nroff and troff
79 . ds #H ((1u-(\\\\n(.fu%2u))*.13m)
85 . \" simple accents for nroff and troff
95 . ds ' \\k:\h'-(\\n(.wu*8/10-\*(#H)'\'\h"|\\n:u"
96 . ds ` \\k:\h'-(\\n(.wu*8/10-\*(#H)'\`\h'|\\n:u'
97 . ds ^ \\k:\h'-(\\n(.wu*10/11-\*(#H)'^\h'|\\n:u'
98 . ds , \\k:\h'-(\\n(.wu*8/10)',\h'|\\n:u'
99 . ds ~ \\k:\h'-(\\n(.wu-\*(#H-.1m)'~\h'|\\n:u'
100 . ds / \\k:\h'-(\\n(.wu*8/10-\*(#H)'\z\(sl\h'|\\n:u'
102 . \" troff and (daisy-wheel) nroff accents
103 .ds : \\k:\h'-(\\n(.wu*8/10-\*(#H+.1m+\*(#F)'\v'-\*(#V'\z.\h'.2m+\*(#F'.\h'|\\n:u'\v'\*(#V'
104 .ds 8 \h'\*(#H'\(*b\h'-\*(#H'
105 .ds o \\k:\h'-(\\n(.wu+\w'\(de'u-\*(#H)/2u'\v'-.3n'\*(#[\z\(de\v'.3n'\h'|\\n:u'\*(#]
106 .ds d- \h'\*(#H'\(pd\h'-\w'~'u'\v'-.25m'\f2\(hy\fP\v'.25m'\h'-\*(#H'
107 .ds D- D\\k:\h'-\w'D'u'\v'-.11m'\z\(hy\v'.11m'\h'|\\n:u'
108 .ds th \*(#[\v'.3m'\s+1I\s-1\v'-.3m'\h'-(\w'I'u*2/3)'\s-1o\s+1\*(#]
109 .ds Th \*(#[\s+2I\s-2\h'-\w'I'u*3/5'\v'-.3m'o\v'.3m'\*(#]
110 .ds ae a\h'-(\w'a'u*4/10)'e
111 .ds Ae A\h'-(\w'A'u*4/10)'E
112 . \" corrections for vroff
113 .if v .ds ~ \\k:\h'-(\\n(.wu*9/10-\*(#H)'\s-2\u~\d\s+2\h'|\\n:u'
114 .if v .ds ^ \\k:\h'-(\\n(.wu*10/11-\*(#H)'\v'-.4m'^\v'.4m'\h'|\\n:u'
115 . \" for low resolution devices (crt and lpr)
116 .if \n(.H>23 .if \n(.V>19 \
129 .\" ========================================================================
132 .TH ecdsa 3 "2017-01-26" "1.0.2k" "OpenSSL"
133 .\" For nroff, turn off justification. Always turn off hyphenation; it makes
134 .\" way too many mistakes in technical documents.
138 ECDSA_SIG_new, ECDSA_SIG_free, i2d_ECDSA_SIG, d2i_ECDSA_SIG, ECDSA_size, ECDSA_sign_setup, ECDSA_sign, ECDSA_sign_ex, ECDSA_verify, ECDSA_do_sign, ECDSA_do_sign_ex, ECDSA_do_verify \- Elliptic Curve Digital Signature Algorithm
140 .IX Header "SYNOPSIS"
142 \& #include <openssl/ecdsa.h>
144 \& ECDSA_SIG* ECDSA_SIG_new(void);
145 \& void ECDSA_SIG_free(ECDSA_SIG *sig);
146 \& int i2d_ECDSA_SIG(const ECDSA_SIG *sig, unsigned char **pp);
147 \& ECDSA_SIG* d2i_ECDSA_SIG(ECDSA_SIG **sig, const unsigned char **pp,
150 \& ECDSA_SIG* ECDSA_do_sign(const unsigned char *dgst, int dgst_len,
152 \& ECDSA_SIG* ECDSA_do_sign_ex(const unsigned char *dgst, int dgstlen,
153 \& const BIGNUM *kinv, const BIGNUM *rp,
155 \& int ECDSA_do_verify(const unsigned char *dgst, int dgst_len,
156 \& const ECDSA_SIG *sig, EC_KEY* eckey);
157 \& int ECDSA_sign_setup(EC_KEY *eckey, BN_CTX *ctx,
158 \& BIGNUM **kinv, BIGNUM **rp);
159 \& int ECDSA_sign(int type, const unsigned char *dgst,
160 \& int dgstlen, unsigned char *sig,
161 \& unsigned int *siglen, EC_KEY *eckey);
162 \& int ECDSA_sign_ex(int type, const unsigned char *dgst,
163 \& int dgstlen, unsigned char *sig,
164 \& unsigned int *siglen, const BIGNUM *kinv,
165 \& const BIGNUM *rp, EC_KEY *eckey);
166 \& int ECDSA_verify(int type, const unsigned char *dgst,
167 \& int dgstlen, const unsigned char *sig,
168 \& int siglen, EC_KEY *eckey);
169 \& int ECDSA_size(const EC_KEY *eckey);
171 \& const ECDSA_METHOD* ECDSA_OpenSSL(void);
172 \& void ECDSA_set_default_method(const ECDSA_METHOD *meth);
173 \& const ECDSA_METHOD* ECDSA_get_default_method(void);
174 \& int ECDSA_set_method(EC_KEY *eckey,const ECDSA_METHOD *meth);
176 \& int ECDSA_get_ex_new_index(long argl, void *argp,
177 \& CRYPTO_EX_new *new_func,
178 \& CRYPTO_EX_dup *dup_func,
179 \& CRYPTO_EX_free *free_func);
180 \& int ECDSA_set_ex_data(EC_KEY *d, int idx, void *arg);
181 \& void* ECDSA_get_ex_data(EC_KEY *d, int idx);
184 .IX Header "DESCRIPTION"
185 The \fB\s-1ECDSA_SIG\s0\fR structure consists of two BIGNUMs for the
186 r and s value of a \s-1ECDSA\s0 signature (see X9.62 or \s-1FIPS 186\-2\s0).
196 \&\fIECDSA_SIG_new()\fR allocates a new \fB\s-1ECDSA_SIG\s0\fR structure (note: this
197 function also allocates the BIGNUMs) and initialize it.
199 \&\fIECDSA_SIG_free()\fR frees the \fB\s-1ECDSA_SIG\s0\fR structure \fBsig\fR.
201 \&\fIi2d_ECDSA_SIG()\fR creates the \s-1DER\s0 encoding of the \s-1ECDSA\s0 signature
202 \&\fBsig\fR and writes the encoded signature to \fB*pp\fR (note: if \fBpp\fR
203 is \s-1NULL \s0\fBi2d_ECDSA_SIG\fR returns the expected length in bytes of
204 the \s-1DER\s0 encoded signature). \fBi2d_ECDSA_SIG\fR returns the length
205 of the \s-1DER\s0 encoded signature (or 0 on error).
207 \&\fId2i_ECDSA_SIG()\fR decodes a \s-1DER\s0 encoded \s-1ECDSA\s0 signature and returns
208 the decoded signature in a newly allocated \fB\s-1ECDSA_SIG\s0\fR structure.
209 \&\fB*sig\fR points to the buffer containing the \s-1DER\s0 encoded signature
212 \&\fIECDSA_size()\fR returns the maximum length of a \s-1DER\s0 encoded
213 \&\s-1ECDSA\s0 signature created with the private \s-1EC\s0 key \fBeckey\fR.
215 \&\fIECDSA_sign_setup()\fR may be used to precompute parts of the
216 signing operation. \fBeckey\fR is the private \s-1EC\s0 key and \fBctx\fR
217 is a pointer to \fB\s-1BN_CTX\s0\fR structure (or \s-1NULL\s0). The precomputed
218 values or returned in \fBkinv\fR and \fBrp\fR and can be used in a
219 later call to \fBECDSA_sign_ex\fR or \fBECDSA_do_sign_ex\fR.
221 \&\fIECDSA_sign()\fR is wrapper function for ECDSA_sign_ex with \fBkinv\fR
222 and \fBrp\fR set to \s-1NULL.\s0
224 \&\fIECDSA_sign_ex()\fR computes a digital signature of the \fBdgstlen\fR bytes
225 hash value \fBdgst\fR using the private \s-1EC\s0 key \fBeckey\fR and the optional
226 pre-computed values \fBkinv\fR and \fBrp\fR. The \s-1DER\s0 encoded signatures is
227 stored in \fBsig\fR and it's length is returned in \fBsig_len\fR. Note: \fBsig\fR
228 must point to \fBECDSA_size\fR bytes of memory. The parameter \fBtype\fR
231 \&\fIECDSA_verify()\fR verifies that the signature in \fBsig\fR of size
232 \&\fBsiglen\fR is a valid \s-1ECDSA\s0 signature of the hash value
233 \&\fBdgst\fR of size \fBdgstlen\fR using the public key \fBeckey\fR.
234 The parameter \fBtype\fR is ignored.
236 \&\fIECDSA_do_sign()\fR is wrapper function for ECDSA_do_sign_ex with \fBkinv\fR
237 and \fBrp\fR set to \s-1NULL.\s0
239 \&\fIECDSA_do_sign_ex()\fR computes a digital signature of the \fBdgst_len\fR
240 bytes hash value \fBdgst\fR using the private key \fBeckey\fR and the
241 optional pre-computed values \fBkinv\fR and \fBrp\fR. The signature is
242 returned in a newly allocated \fB\s-1ECDSA_SIG\s0\fR structure (or \s-1NULL\s0 on error).
244 \&\fIECDSA_do_verify()\fR verifies that the signature \fBsig\fR is a valid
245 \&\s-1ECDSA\s0 signature of the hash value \fBdgst\fR of size \fBdgst_len\fR
246 using the public key \fBeckey\fR.
248 .IX Header "RETURN VALUES"
249 \&\fIECDSA_size()\fR returns the maximum length signature or 0 on error.
251 \&\fIECDSA_sign_setup()\fR and \fIECDSA_sign()\fR return 1 if successful or 0
254 \&\fIECDSA_verify()\fR and \fIECDSA_do_verify()\fR return 1 for a valid
255 signature, 0 for an invalid signature and \-1 on error.
256 The error codes can be obtained by \fIERR_get_error\fR\|(3).
258 .IX Header "EXAMPLES"
259 Creating a \s-1ECDSA\s0 signature of given \s-1SHA\-1\s0 hash value using the
260 named curve secp192k1.
262 First step: create a \s-1EC_KEY\s0 object (note: this part is \fBnot\fR \s-1ECDSA\s0
269 \& eckey = EC_KEY_new_by_curve_name(NID_secp192k1);
270 \& if (eckey == NULL)
274 \& if (!EC_KEY_generate_key(eckey))
280 Second step: compute the \s-1ECDSA\s0 signature of a \s-1SHA\-1\s0 hash value
281 using \fBECDSA_do_sign\fR
284 \& sig = ECDSA_do_sign(digest, 20, eckey);
291 or using \fBECDSA_sign\fR
294 \& unsigned char *buffer, *pp;
296 \& buf_len = ECDSA_size(eckey);
297 \& buffer = OPENSSL_malloc(buf_len);
299 \& if (!ECDSA_sign(0, dgst, dgstlen, pp, &buf_len, eckey);
305 Third step: verify the created \s-1ECDSA\s0 signature using \fBECDSA_do_verify\fR
308 \& ret = ECDSA_do_verify(digest, 20, sig, eckey);
311 or using \fBECDSA_verify\fR
314 \& ret = ECDSA_verify(0, digest, 20, buffer, buf_len, eckey);
317 and finally evaluate the return value:
324 \& else if (ret == 0)
326 \& /* incorrect signature */
328 \& else /* ret == 1 */
330 \& /* signature ok */
334 .IX Header "CONFORMING TO"
335 \&\s-1ANSI X9.62, US\s0 Federal Information Processing Standard \s-1FIPS 186\-2
336 \&\s0(Digital Signature Standard, \s-1DSS\s0)
338 .IX Header "SEE ALSO"
339 \&\fIdsa\fR\|(3), \fIrsa\fR\|(3)
342 The ecdsa implementation was first introduced in OpenSSL 0.9.8
345 Nils Larsch for the OpenSSL project (http://www.openssl.org).