diff options
Diffstat (limited to 'openssl/crypto/ecdh/ech_kdf.c')
| -rw-r--r-- | openssl/crypto/ecdh/ech_kdf.c | 111 |
1 files changed, 111 insertions, 0 deletions
diff --git a/openssl/crypto/ecdh/ech_kdf.c b/openssl/crypto/ecdh/ech_kdf.c new file mode 100644 index 0000000..ac722ac --- /dev/null +++ b/openssl/crypto/ecdh/ech_kdf.c @@ -0,0 +1,111 @@ +/* crypto/ecdh/ec_kdf.c */ +/* + * Written by Stephen Henson for the OpenSSL project. + */ +/* ==================================================================== + * Copyright (c) 2013 The OpenSSL Project. All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in + * the documentation and/or other materials provided with the + * distribution. + * + * 3. All advertising materials mentioning features or use of this + * software must display the following acknowledgment: + * "This product includes software developed by the OpenSSL Project + * for use in the OpenSSL Toolkit. (http://www.openssl.org/)" + * + * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to + * endorse or promote products derived from this software without + * prior written permission. For written permission, please contact + * openssl-core@openssl.org. + * + * 5. Products derived from this software may not be called "OpenSSL" + * nor may "OpenSSL" appear in their names without prior written + * permission of the OpenSSL Project. + * + * 6. Redistributions of any form whatsoever must retain the following + * acknowledgment: + * "This product includes software developed by the OpenSSL Project + * for use in the OpenSSL Toolkit (http://www.openssl.org/)" + * + * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY + * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR + * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE OpenSSL PROJECT OR + * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, + * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT + * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; + * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) + * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, + * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) + * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED + * OF THE POSSIBILITY OF SUCH DAMAGE. + * ==================================================================== + */ + +#define OPENSSL_FIPSAPI + +#include <string.h> +#include <openssl/ecdh.h> +#include <openssl/evp.h> + +/* Key derivation function from X9.62/SECG */ +/* Way more than we will ever need */ +#define ECDH_KDF_MAX (1 << 30) + +int ECDH_KDF_X9_62(unsigned char *out, size_t outlen, + const unsigned char *Z, size_t Zlen, + const unsigned char *sinfo, size_t sinfolen, + const EVP_MD *md) +{ + EVP_MD_CTX mctx; + int rv = 0; + unsigned int i; + size_t mdlen; + unsigned char ctr[4]; + if (sinfolen > ECDH_KDF_MAX || outlen > ECDH_KDF_MAX + || Zlen > ECDH_KDF_MAX) + return 0; + mdlen = EVP_MD_size(md); + EVP_MD_CTX_init(&mctx); + for (i = 1;; i++) { + unsigned char mtmp[EVP_MAX_MD_SIZE]; + EVP_DigestInit_ex(&mctx, md, NULL); + ctr[3] = i & 0xFF; + ctr[2] = (i >> 8) & 0xFF; + ctr[1] = (i >> 16) & 0xFF; + ctr[0] = (i >> 24) & 0xFF; + if (!EVP_DigestUpdate(&mctx, Z, Zlen)) + goto err; + if (!EVP_DigestUpdate(&mctx, ctr, sizeof(ctr))) + goto err; + if (!EVP_DigestUpdate(&mctx, sinfo, sinfolen)) + goto err; + if (outlen >= mdlen) { + if (!EVP_DigestFinal(&mctx, out, NULL)) + goto err; + outlen -= mdlen; + if (outlen == 0) + break; + out += mdlen; + } else { + if (!EVP_DigestFinal(&mctx, mtmp, NULL)) + goto err; + memcpy(out, mtmp, outlen); + OPENSSL_cleanse(mtmp, mdlen); + break; + } + } + rv = 1; + err: + EVP_MD_CTX_cleanup(&mctx); + return rv; +} |