--- /dev/null
+/* fips_dsa_sign.c */
+/* Written by Dr Stephen N Henson (shenson@bigfoot.com) for the OpenSSL
+ * project 2007.
+ */
+/* ====================================================================
+ * Copyright (c) 2007 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
+ * licensing@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.
+ * ====================================================================
+ *
+ * This product includes cryptographic software written by Eric Young
+ * (eay@cryptsoft.com). This product includes software written by Tim
+ * Hudson (tjh@cryptsoft.com).
+ *
+ */
+
+#include <string.h>
+#include <openssl/evp.h>
+#include <openssl/dsa.h>
+#include <openssl/err.h>
+#include <openssl/sha.h>
+
+#ifdef OPENSSL_FIPS
+
+/* FIPS versions of DSA_sign() and DSA_verify().
+ * These include a tiny ASN1 encoder/decoder to handle the specific
+ * case of a DSA signature.
+ */
+
+int FIPS_dsa_size(DSA *r)
+ {
+ int ilen;
+ ilen = BN_num_bytes(r->q);
+ if (ilen > 20)
+ return -1;
+ /* If MSB set need padding byte */
+ ilen ++;
+ /* Also need 2 bytes INTEGER header for r and s plus
+ * 2 bytes SEQUENCE header making 6 in total.
+ */
+ return ilen * 2 + 6;
+ }
+
+/* Tiny ASN1 encoder for DSA_SIG structure. We can assume r, s smaller than
+ * 0x80 octets as by the DSA standards they will be less than 2^160
+ */
+
+int FIPS_dsa_sig_encode(unsigned char *out, DSA_SIG *sig)
+ {
+ int rlen, slen, rpad, spad, seqlen;
+ rlen = BN_num_bytes(sig->r);
+ if (rlen > 20)
+ return -1;
+ if (BN_num_bits(sig->r) & 0x7)
+ rpad = 0;
+ else
+ rpad = 1;
+ slen = BN_num_bytes(sig->s);
+ if (slen > 20)
+ return -1;
+ if (BN_num_bits(sig->s) & 0x7)
+ spad = 0;
+ else
+ spad = 1;
+ /* Length of SEQUENCE, (1 tag + 1 len octet) * 2 + content octets */
+ seqlen = rlen + rpad + slen + spad + 4;
+ /* Actual encoded length: include SEQUENCE header */
+ if (!out)
+ return seqlen + 2;
+
+ /* Output SEQUENCE header */
+ *out++ = V_ASN1_SEQUENCE|V_ASN1_CONSTRUCTED;
+ *out++ = (unsigned char)seqlen;
+
+ /* Output r */
+ *out++ = V_ASN1_INTEGER;
+ *out++ = (unsigned char)(rlen + rpad);
+ if (rpad)
+ *out++ = 0;
+ BN_bn2bin(sig->r, out);
+ out += rlen;
+
+ /* Output s */
+ *out++ = V_ASN1_INTEGER;
+ *out++ = (unsigned char)(slen + spad);
+ if (spad)
+ *out++ = 0;
+ BN_bn2bin(sig->s, out);
+ return seqlen + 2;
+ }
+
+/* Companion DSA_SIG decoder */
+
+int FIPS_dsa_sig_decode(DSA_SIG *sig, const unsigned char *in, int inlen)
+ {
+ int seqlen, rlen, slen;
+ const unsigned char *rbin;
+ /* Sanity check */
+
+ /* Need SEQUENCE tag */
+ if (*in++ != (V_ASN1_SEQUENCE|V_ASN1_CONSTRUCTED))
+ return 0;
+ /* Get length octet */
+ seqlen = *in++;
+ /* Check sensible length value */
+ if (seqlen < 4 || seqlen > 0x7F)
+ return 0;
+ /* Check INTEGER tag */
+ if (*in++ != V_ASN1_INTEGER)
+ return 0;
+ rlen = *in++;
+ seqlen -= 2 + rlen;
+ /* Check sensible seqlen value */
+ if (seqlen < 2)
+ return 0;
+ rbin = in;
+ in += rlen;
+ /* Check INTEGER tag */
+ if (*in++ != V_ASN1_INTEGER)
+ return 0;
+ slen = *in++;
+ /* Remaining bytes of SEQUENCE should exactly match
+ * encoding of s
+ */
+ if (seqlen != (slen + 2))
+ return 0;
+ if (!sig->r && !(sig->r = BN_new()))
+ return 0;
+ if (!sig->s && !(sig->s = BN_new()))
+ return 0;
+ if (!BN_bin2bn(rbin, rlen, sig->r))
+ return 0;
+ if (!BN_bin2bn(in, slen, sig->s))
+ return 0;
+ return 1;
+ }
+
+static int fips_dsa_sign(int type, const unsigned char *dgst, int dlen,
+ unsigned char *sig, unsigned int *siglen, DSA *dsa)
+ {
+ DSA_SIG *s;
+ s=dsa->meth->dsa_do_sign(dgst,dlen,dsa);
+ if (s == NULL)
+ {
+ *siglen=0;
+ return 0;
+ }
+ *siglen= FIPS_dsa_sig_encode(sig, s);
+ DSA_SIG_free(s);
+ if (*siglen < 0)
+ return 0;
+ return 1;
+ }
+
+static int fips_dsa_verify(int type, const unsigned char *dgst, int dgst_len,
+ const unsigned char *sigbuf, int siglen, DSA *dsa)
+ {
+ DSA_SIG *s;
+ int ret=-1;
+
+ s = DSA_SIG_new();
+ if (s == NULL)
+ return ret;
+ if (!FIPS_dsa_sig_decode(s,sigbuf,siglen))
+ goto err;
+ ret=dsa->meth->dsa_do_verify(dgst,dgst_len,s,dsa);
+err:
+ DSA_SIG_free(s);
+ return ret;
+ }
+
+static int init(EVP_MD_CTX *ctx)
+ { return SHA1_Init(ctx->md_data); }
+
+static int update(EVP_MD_CTX *ctx,const void *data,size_t count)
+ { return SHA1_Update(ctx->md_data,data,count); }
+
+static int final(EVP_MD_CTX *ctx,unsigned char *md)
+ { return SHA1_Final(md,ctx->md_data); }
+
+static const EVP_MD dss1_md=
+ {
+ NID_dsa,
+ NID_dsaWithSHA1,
+ SHA_DIGEST_LENGTH,
+ EVP_MD_FLAG_FIPS,
+ init,
+ update,
+ final,
+ NULL,
+ NULL,
+ (evp_sign_method *)fips_dsa_sign,
+ (evp_verify_method *)fips_dsa_verify,
+ {EVP_PKEY_DSA,EVP_PKEY_DSA2,EVP_PKEY_DSA3, EVP_PKEY_DSA4,0},
+ SHA_CBLOCK,
+ sizeof(EVP_MD *)+sizeof(SHA_CTX),
+ };
+
+const EVP_MD *EVP_dss1(void)
+ {
+ return(&dss1_md);
+ }
+#endif
projects / oweals / openssl.git / commitdiff