1 /***********************************************************************
2 * Copyright (c) 2014, 2015 Pieter Wuille *
3 * Distributed under the MIT software license, see the accompanying *
4 * file COPYING or https://www.opensource.org/licenses/mit-license.php.*
5 ***********************************************************************/
6 7 /****
8 * Please do not link this file directly. It is not part of the libsecp256k1
9 * project and does not promise any stability in its API, functionality or
10 * presence. Projects which use this code should instead copy this header
11 * and its accompanying .c file directly into their codebase.
12 ****/
13 14 /* This file contains code snippets that parse DER private keys with
15 * various errors and violations. This is not a part of the library
16 * itself, because the allowed violations are chosen arbitrarily and
17 * do not follow or establish any standard.
18 *
19 * It also contains code to serialize private keys in a compatible
20 * manner.
21 *
22 * These functions are meant for compatibility with applications
23 * that require BER encoded keys. When working with secp256k1-specific
24 * code, the simple 32-byte private keys normally used by the
25 * library are sufficient.
26 */
27 28 #ifndef SECP256K1_CONTRIB_BER_PRIVATEKEY_H
29 #define SECP256K1_CONTRIB_BER_PRIVATEKEY_H
30 31 /* #include secp256k1.h only when it hasn't been included yet.
32 This enables this file to be #included directly in other project
33 files (such as tests.c) without the need to set an explicit -I flag,
34 which would be necessary to locate secp256k1.h. */
35 #ifndef SECP256K1_H
36 #include <secp256k1.h>
37 #endif
38 39 #ifdef __cplusplus
40 extern "C" {
41 #endif
42 43 /** Export a private key in DER format.
44 *
45 * Returns: 1 if the private key was valid.
46 * Args: ctx: pointer to a context object (not secp256k1_context_static).
47 * Out: privkey: pointer to an array for storing the private key in BER.
48 * Should have space for 279 bytes, and cannot be NULL.
49 * privkeylen: Pointer to an int where the length of the private key in
50 * privkey will be stored.
51 * In: seckey: pointer to a 32-byte secret key to export.
52 * compressed: 1 if the key should be exported in
53 * compressed format, 0 otherwise
54 *
55 * This function is purely meant for compatibility with applications that
56 * require BER encoded keys. When working with secp256k1-specific code, the
57 * simple 32-byte private keys are sufficient.
58 *
59 * Note that this function does not guarantee correct DER output. It is
60 * guaranteed to be parsable by secp256k1_ec_privkey_import_der
61 */
62 SECP256K1_WARN_UNUSED_RESULT int ec_privkey_export_der(
63 const secp256k1_context* ctx,
64 unsigned char *privkey,
65 size_t *privkeylen,
66 const unsigned char *seckey,
67 int compressed
68 ) SECP256K1_ARG_NONNULL(1) SECP256K1_ARG_NONNULL(2) SECP256K1_ARG_NONNULL(3) SECP256K1_ARG_NONNULL(4);
69 70 /** Import a private key in DER format.
71 * Returns: 1 if a private key was extracted.
72 * Args: ctx: pointer to a context object (cannot be NULL).
73 * Out: seckey: pointer to a 32-byte array for storing the private key.
74 * (cannot be NULL).
75 * In: privkey: pointer to a private key in DER format (cannot be NULL).
76 * privkeylen: length of the DER private key pointed to be privkey.
77 *
78 * This function will accept more than just strict DER, and even allow some BER
79 * violations. The public key stored inside the DER-encoded private key is not
80 * verified for correctness, nor are the curve parameters. Use this function
81 * only if you know in advance it is supposed to contain a secp256k1 private
82 * key.
83 */
84 SECP256K1_WARN_UNUSED_RESULT int ec_privkey_import_der(
85 const secp256k1_context* ctx,
86 unsigned char *seckey,
87 const unsigned char *privkey,
88 size_t privkeylen
89 ) SECP256K1_ARG_NONNULL(1) SECP256K1_ARG_NONNULL(2) SECP256K1_ARG_NONNULL(3);
90 91 #ifdef __cplusplus
92 }
93 #endif
94 95 #endif /* SECP256K1_CONTRIB_BER_PRIVATEKEY_H */
96