1/* ====================================================================
2 * Copyright (c) 1998-2005 The OpenSSL Project.  All rights reserved.
3 *
4 * Redistribution and use in source and binary forms, with or without
5 * modification, are permitted provided that the following conditions
6 * are met:
7 *
8 * 1. Redistributions of source code must retain the above copyright
9 *    notice, this list of conditions and the following disclaimer.
10 *
11 * 2. Redistributions in binary form must reproduce the above copyright
12 *    notice, this list of conditions and the following disclaimer in
13 *    the documentation and/or other materials provided with the
14 *    distribution.
15 *
16 * 3. All advertising materials mentioning features or use of this
17 *    software must display the following acknowledgment:
18 *    "This product includes software developed by the OpenSSL Project
19 *    for use in the OpenSSL Toolkit. (http://www.OpenSSL.org/)"
20 *
21 * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
22 *    endorse or promote products derived from this software without
23 *    prior written permission. For written permission, please contact
24 *    openssl-core@OpenSSL.org.
25 *
26 * 5. Products derived from this software may not be called "OpenSSL"
27 *    nor may "OpenSSL" appear in their names without prior written
28 *    permission of the OpenSSL Project.
29 *
30 * 6. Redistributions of any form whatsoever must retain the following
31 *    acknowledgment:
32 *    "This product includes software developed by the OpenSSL Project
33 *    for use in the OpenSSL Toolkit (http://www.OpenSSL.org/)"
34 *
35 * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
36 * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
37 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
38 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE OpenSSL PROJECT OR
39 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
40 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
41 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
42 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
43 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
44 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
45 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
46 * OF THE POSSIBILITY OF SUCH DAMAGE.
47 * ====================================================================
48 *
49 * This product includes cryptographic software written by Eric Young
50 * (eay@cryptsoft.com).  This product includes software written by Tim
51 * Hudson (tjh@cryptsoft.com). */
52
53#ifndef OPENSSL_HEADER_ECDSA_H
54#define OPENSSL_HEADER_ECDSA_H
55
56#include <openssl/base.h>
57
58#include <openssl/ec_key.h>
59
60#if defined(__cplusplus)
61extern "C" {
62#endif
63
64
65/* ECDSA contains functions for signing and verifying with the Digital Signature
66 * Algorithm over elliptic curves. */
67
68
69/* Signing and verifying. */
70
71/* ECDSA_sign signs |digest_len| bytes from |digest| with |key| and writes the
72 * resulting signature to |sig|, which must have |ECDSA_size(key)| bytes of
73 * space. On successful exit, |*sig_len| is set to the actual number of bytes
74 * written. The |type| argument should be zero. It returns one on success and
75 * zero otherwise. */
76OPENSSL_EXPORT int ECDSA_sign(int type, const uint8_t *digest,
77                              size_t digest_len, uint8_t *sig,
78                              unsigned int *sig_len, const EC_KEY *key);
79
80/* ECDSA_verify verifies that |sig_len| bytes from |sig| constitute a valid
81 * signature by |key| of |digest|. (The |type| argument should be zero.) It
82 * returns one on success or zero if the signature is invalid or an error
83 * occurred. */
84OPENSSL_EXPORT int ECDSA_verify(int type, const uint8_t *digest,
85                                size_t digest_len, const uint8_t *sig,
86                                size_t sig_len, const EC_KEY *key);
87
88/* ECDSA_size returns the maximum size of an ECDSA signature using |key|. It
89 * returns zero on error. */
90OPENSSL_EXPORT size_t ECDSA_size(const EC_KEY *key);
91
92
93/* Low-level signing and verification.
94 *
95 * Low-level functions handle signatures as |ECDSA_SIG| structures which allow
96 * the two values in an ECDSA signature to be handled separately. */
97
98struct ecdsa_sig_st {
99  BIGNUM *r;
100  BIGNUM *s;
101};
102
103/* ECDSA_SIG_new returns a fresh |ECDSA_SIG| structure or NULL on error. */
104OPENSSL_EXPORT ECDSA_SIG *ECDSA_SIG_new(void);
105
106/* ECDSA_SIG_free frees |sig| its member |BIGNUM|s. */
107OPENSSL_EXPORT void ECDSA_SIG_free(ECDSA_SIG *sig);
108
109/* ECDSA_do_sign signs |digest_len| bytes from |digest| with |key| and returns
110 * the resulting signature structure, or NULL on error. */
111OPENSSL_EXPORT ECDSA_SIG *ECDSA_do_sign(const uint8_t *digest,
112                                        size_t digest_len, const EC_KEY *key);
113
114/* ECDSA_do_verify verifies that |sig| constitutes a valid signature by |key|
115 * of |digest|. It returns one on success or zero if the signature is invalid
116 * or on error. */
117OPENSSL_EXPORT int ECDSA_do_verify(const uint8_t *digest, size_t digest_len,
118                                   const ECDSA_SIG *sig, const EC_KEY *key);
119
120
121/* Signing with precomputation.
122 *
123 * Parts of the ECDSA signature can be independent of the message to be signed
124 * thus it's possible to precompute them and reduce the signing latency.
125 *
126 * TODO(fork): remove support for this as it cannot support safe-randomness. */
127
128/* ECDSA_sign_setup precomputes parts of an ECDSA signing operation. It sets
129 * |*kinv| and |*rp| to the precomputed values and uses the |ctx| argument, if
130 * not NULL. It returns one on success and zero otherwise. */
131OPENSSL_EXPORT int ECDSA_sign_setup(const EC_KEY *eckey, BN_CTX *ctx,
132                                    BIGNUM **kinv, BIGNUM **rp);
133
134/* ECDSA_do_sign_ex is the same as |ECDSA_do_sign| but takes precomputed values
135 * as generated by |ECDSA_sign_setup|. */
136OPENSSL_EXPORT ECDSA_SIG *ECDSA_do_sign_ex(const uint8_t *digest,
137                                           size_t digest_len,
138                                           const BIGNUM *kinv, const BIGNUM *rp,
139                                           const EC_KEY *eckey);
140
141/* ECDSA_sign_ex is the same as |ECDSA_sign| but takes precomputed values as
142 * generated by |ECDSA_sign_setup|. */
143OPENSSL_EXPORT int ECDSA_sign_ex(int type, const uint8_t *digest,
144                                 size_t digest_len, uint8_t *sig,
145                                 unsigned int *sig_len, const BIGNUM *kinv,
146                                 const BIGNUM *rp, const EC_KEY *eckey);
147
148
149/* ASN.1 functions. */
150
151/* ECDSA_SIG_parse parses a DER-encoded ECDSA-Sig-Value structure from |cbs| and
152 * advances |cbs|. It returns a newly-allocated |ECDSA_SIG| or NULL on error. */
153OPENSSL_EXPORT ECDSA_SIG *ECDSA_SIG_parse(CBS *cbs);
154
155/* ECDSA_SIG_from_bytes parses |in| as a DER-encoded ECDSA-Sig-Value structure.
156 * It returns a newly-allocated |ECDSA_SIG| structure or NULL on error. */
157OPENSSL_EXPORT ECDSA_SIG *ECDSA_SIG_from_bytes(const uint8_t *in,
158                                               size_t in_len);
159
160/* ECDSA_SIG_marshal marshals |sig| as a DER-encoded ECDSA-Sig-Value and appends
161 * the result to |cbb|. It returns one on success and zero on error. */
162OPENSSL_EXPORT int ECDSA_SIG_marshal(CBB *cbb, const ECDSA_SIG *sig);
163
164/* ECDSA_SIG_to_bytes marshals |sig| as a DER-encoded ECDSA-Sig-Value and, on
165 * success, sets |*out_bytes| to a newly allocated buffer containing the result
166 * and returns one. Otherwise, it returns zero. The result should be freed with
167 * |OPENSSL_free|. */
168OPENSSL_EXPORT int ECDSA_SIG_to_bytes(uint8_t **out_bytes, size_t *out_len,
169                                      const ECDSA_SIG *sig);
170
171/* ECDSA_SIG_max_len returns the maximum length of a DER-encoded ECDSA-Sig-Value
172 * structure for a group whose order is represented in |order_len| bytes, or
173 * zero on overflow. */
174OPENSSL_EXPORT size_t ECDSA_SIG_max_len(size_t order_len);
175
176
177/* Deprecated functions. */
178
179/* d2i_ECDSA_SIG parses an ASN.1, DER-encoded, signature from |len| bytes at
180 * |*inp|. If |out| is not NULL then, on exit, a pointer to the result is in
181 * |*out|. Note that, even if |*out| is already non-NULL on entry, it will not
182 * be written to. Rather, a fresh |ECDSA_SIG| is allocated and the previous one
183 * is freed. On successful exit, |*inp| is advanced past the DER structure. It
184 * returns the result or NULL on error. */
185OPENSSL_EXPORT ECDSA_SIG *d2i_ECDSA_SIG(ECDSA_SIG **out, const uint8_t **inp,
186                                        long len);
187
188/* i2d_ECDSA_SIG marshals a signature from |sig| to an ASN.1, DER
189 * structure. If |outp| is not NULL then the result is written to |*outp| and
190 * |*outp| is advanced just past the output. It returns the number of bytes in
191 * the result, whether written or not, or a negative value on error. */
192OPENSSL_EXPORT int i2d_ECDSA_SIG(const ECDSA_SIG *sig, uint8_t **outp);
193
194
195#if defined(__cplusplus)
196}  /* extern C */
197
198extern "C++" {
199
200namespace bssl {
201
202BORINGSSL_MAKE_DELETER(ECDSA_SIG, ECDSA_SIG_free)
203
204}  // namespace bssl
205
206}  /* extern C++ */
207
208#endif
209
210#define ECDSA_R_BAD_SIGNATURE 100
211#define ECDSA_R_MISSING_PARAMETERS 101
212#define ECDSA_R_NEED_NEW_SETUP_VALUES 102
213#define ECDSA_R_NOT_IMPLEMENTED 103
214#define ECDSA_R_RANDOM_NUMBER_GENERATION_FAILED 104
215#define ECDSA_R_ENCODE_ERROR 105
216
217#endif  /* OPENSSL_HEADER_ECDSA_H */
218