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. 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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) 61 extern "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. 76 // 77 // WARNING: |digest| must be the output of some hash function on the data to be 78 // signed. Passing unhashed inputs will not result in a secure signature scheme. 79 OPENSSL_EXPORT int ECDSA_sign(int type, const uint8_t *digest, 80 size_t digest_len, uint8_t *sig, 81 unsigned int *sig_len, const EC_KEY *key); 82 83 // ECDSA_verify verifies that |sig_len| bytes from |sig| constitute a valid 84 // signature by |key| of |digest|. (The |type| argument should be zero.) It 85 // returns one on success or zero if the signature is invalid or an error 86 // occurred. 87 // 88 // WARNING: |digest| must be the output of some hash function on the data to be 89 // verified. Passing unhashed inputs will not result in a secure signature 90 // scheme. 91 OPENSSL_EXPORT int ECDSA_verify(int type, const uint8_t *digest, 92 size_t digest_len, const uint8_t *sig, 93 size_t sig_len, const EC_KEY *key); 94 95 // ECDSA_size returns the maximum size of an ECDSA signature using |key|. It 96 // returns zero if |key| is NULL or if it doesn't have a group set. 97 OPENSSL_EXPORT size_t ECDSA_size(const EC_KEY *key); 98 99 100 // Low-level signing and verification. 101 // 102 // Low-level functions handle signatures as |ECDSA_SIG| structures which allow 103 // the two values in an ECDSA signature to be handled separately. 104 105 struct ecdsa_sig_st { 106 BIGNUM *r; 107 BIGNUM *s; 108 }; 109 110 // ECDSA_SIG_new returns a fresh |ECDSA_SIG| structure or NULL on error. 111 OPENSSL_EXPORT ECDSA_SIG *ECDSA_SIG_new(void); 112 113 // ECDSA_SIG_free frees |sig| its member |BIGNUM|s. 114 OPENSSL_EXPORT void ECDSA_SIG_free(ECDSA_SIG *sig); 115 116 // ECDSA_SIG_get0_r returns the r component of |sig|. 117 OPENSSL_EXPORT const BIGNUM *ECDSA_SIG_get0_r(const ECDSA_SIG *sig); 118 119 // ECDSA_SIG_get0_s returns the s component of |sig|. 120 OPENSSL_EXPORT const BIGNUM *ECDSA_SIG_get0_s(const ECDSA_SIG *sig); 121 122 // ECDSA_SIG_get0 sets |*out_r| and |*out_s|, if non-NULL, to the two 123 // components of |sig|. 124 OPENSSL_EXPORT void ECDSA_SIG_get0(const ECDSA_SIG *sig, const BIGNUM **out_r, 125 const BIGNUM **out_s); 126 127 // ECDSA_SIG_set0 sets |sig|'s components to |r| and |s|, neither of which may 128 // be NULL. On success, it takes ownership of each argument and returns one. 129 // Otherwise, it returns zero. 130 OPENSSL_EXPORT int ECDSA_SIG_set0(ECDSA_SIG *sig, BIGNUM *r, BIGNUM *s); 131 132 // ECDSA_do_sign signs |digest_len| bytes from |digest| with |key| and returns 133 // the resulting signature structure, or NULL on error. 134 // 135 // WARNING: |digest| must be the output of some hash function on the data to be 136 // signed. Passing unhashed inputs will not result in a secure signature scheme. 137 OPENSSL_EXPORT ECDSA_SIG *ECDSA_do_sign(const uint8_t *digest, 138 size_t digest_len, const EC_KEY *key); 139 140 // ECDSA_do_verify verifies that |sig| constitutes a valid signature by |key| 141 // of |digest|. It returns one on success or zero if the signature is invalid 142 // or on error. 143 // 144 // WARNING: |digest| must be the output of some hash function on the data to be 145 // verified. Passing unhashed inputs will not result in a secure signature 146 // scheme. 147 OPENSSL_EXPORT int ECDSA_do_verify(const uint8_t *digest, size_t digest_len, 148 const ECDSA_SIG *sig, const EC_KEY *key); 149 150 151 // ASN.1 functions. 152 153 // ECDSA_SIG_parse parses a DER-encoded ECDSA-Sig-Value structure from |cbs| and 154 // advances |cbs|. It returns a newly-allocated |ECDSA_SIG| or NULL on error. 155 OPENSSL_EXPORT ECDSA_SIG *ECDSA_SIG_parse(CBS *cbs); 156 157 // ECDSA_SIG_from_bytes parses |in| as a DER-encoded ECDSA-Sig-Value structure. 158 // It returns a newly-allocated |ECDSA_SIG| structure or NULL on error. 159 OPENSSL_EXPORT ECDSA_SIG *ECDSA_SIG_from_bytes(const uint8_t *in, 160 size_t in_len); 161 162 // ECDSA_SIG_marshal marshals |sig| as a DER-encoded ECDSA-Sig-Value and appends 163 // the result to |cbb|. It returns one on success and zero on error. 164 OPENSSL_EXPORT int ECDSA_SIG_marshal(CBB *cbb, const ECDSA_SIG *sig); 165 166 // ECDSA_SIG_to_bytes marshals |sig| as a DER-encoded ECDSA-Sig-Value and, on 167 // success, sets |*out_bytes| to a newly allocated buffer containing the result 168 // and returns one. Otherwise, it returns zero. The result should be freed with 169 // |OPENSSL_free|. 170 OPENSSL_EXPORT int ECDSA_SIG_to_bytes(uint8_t **out_bytes, size_t *out_len, 171 const ECDSA_SIG *sig); 172 173 // ECDSA_SIG_max_len returns the maximum length of a DER-encoded ECDSA-Sig-Value 174 // structure for a group whose order is represented in |order_len| bytes, or 175 // zero on overflow. 176 OPENSSL_EXPORT size_t ECDSA_SIG_max_len(size_t order_len); 177 178 179 // Testing-only functions. 180 181 // ECDSA_sign_with_nonce_and_leak_private_key_for_testing behaves like 182 // |ECDSA_do_sign| but uses |nonce| for the ECDSA nonce 'k', instead of a random 183 // value. |nonce| is interpreted as a big-endian integer. It must be reduced 184 // modulo the group order and padded with zeros up to |BN_num_bytes(order)| 185 // bytes. 186 // 187 // WARNING: This function is only exported for testing purposes, when using test 188 // vectors or fuzzing strategies. It must not be used outside tests and may leak 189 // any private keys it is used with. 190 OPENSSL_EXPORT ECDSA_SIG * 191 ECDSA_sign_with_nonce_and_leak_private_key_for_testing(const uint8_t *digest, 192 size_t digest_len, 193 const EC_KEY *eckey, 194 const uint8_t *nonce, 195 size_t nonce_len); 196 197 198 // Deprecated functions. 199 200 // d2i_ECDSA_SIG parses an ASN.1, DER-encoded, signature from |len| bytes at 201 // |*inp|. If |out| is not NULL then, on exit, a pointer to the result is in 202 // |*out|. Note that, even if |*out| is already non-NULL on entry, it will not 203 // be written to. Rather, a fresh |ECDSA_SIG| is allocated and the previous one 204 // is freed. On successful exit, |*inp| is advanced past the DER structure. It 205 // returns the result or NULL on error. 206 OPENSSL_EXPORT ECDSA_SIG *d2i_ECDSA_SIG(ECDSA_SIG **out, const uint8_t **inp, 207 long len); 208 209 // i2d_ECDSA_SIG marshals a signature from |sig| to an ASN.1, DER 210 // structure. If |outp| is not NULL then the result is written to |*outp| and 211 // |*outp| is advanced just past the output. It returns the number of bytes in 212 // the result, whether written or not, or a negative value on error. 213 OPENSSL_EXPORT int i2d_ECDSA_SIG(const ECDSA_SIG *sig, uint8_t **outp); 214 215 216 #if defined(__cplusplus) 217 } // extern C 218 219 extern "C++" { 220 221 BSSL_NAMESPACE_BEGIN 222 223 BORINGSSL_MAKE_DELETER(ECDSA_SIG, ECDSA_SIG_free) 224 225 BSSL_NAMESPACE_END 226 227 } // extern C++ 228 229 #endif 230 231 #define ECDSA_R_BAD_SIGNATURE 100 232 #define ECDSA_R_MISSING_PARAMETERS 101 233 #define ECDSA_R_NEED_NEW_SETUP_VALUES 102 234 #define ECDSA_R_NOT_IMPLEMENTED 103 235 #define ECDSA_R_RANDOM_NUMBER_GENERATION_FAILED 104 236 #define ECDSA_R_ENCODE_ERROR 105 237 238 #endif // OPENSSL_HEADER_ECDSA_H 239