/* fips_rsa_sign.c */
/*
 * Written by Dr Stephen N Henson (steve@openssl.org) 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/rsa.h>
#include <openssl/err.h>
#include <openssl/sha.h>

#ifdef OPENSSL_FIPS

/*
 * FIPS versions of RSA_sign() and RSA_verify(). These will only have to deal
 * with SHA* signatures and by including pregenerated encodings all ASN1
 * dependencies can be avoided
 */

/* Standard encodings including NULL parameter */

static const unsigned char sha1_bin[] = {
    0x30, 0x21, 0x30, 0x09, 0x06, 0x05, 0x2b, 0x0e, 0x03, 0x02, 0x1a, 0x05,
    0x00, 0x04, 0x14
};

static const unsigned char sha224_bin[] = {
    0x30, 0x2d, 0x30, 0x0d, 0x06, 0x09, 0x60, 0x86, 0x48, 0x01, 0x65, 0x03,
    0x04, 0x02, 0x04, 0x05, 0x00, 0x04, 0x1c
};

static const unsigned char sha256_bin[] = {
    0x30, 0x31, 0x30, 0x0d, 0x06, 0x09, 0x60, 0x86, 0x48, 0x01, 0x65, 0x03,
    0x04, 0x02, 0x01, 0x05, 0x00, 0x04, 0x20
};

static const unsigned char sha384_bin[] = {
    0x30, 0x41, 0x30, 0x0d, 0x06, 0x09, 0x60, 0x86, 0x48, 0x01, 0x65, 0x03,
    0x04, 0x02, 0x02, 0x05, 0x00, 0x04, 0x30
};

static const unsigned char sha512_bin[] = {
    0x30, 0x51, 0x30, 0x0d, 0x06, 0x09, 0x60, 0x86, 0x48, 0x01, 0x65, 0x03,
    0x04, 0x02, 0x03, 0x05, 0x00, 0x04, 0x40
};

/*
 * Alternate encodings with absent parameters. We don't generate signature
 * using this format but do tolerate received signatures of this form.
 */

static unsigned char sha1_nn_bin[] = {
    0x30, 0x1f, 0x30, 0x07, 0x06, 0x05, 0x2b, 0x0e, 0x03, 0x02, 0x1a, 0x04,
    0x14
};

static unsigned char sha224_nn_bin[] = {
    0x30, 0x2b, 0x30, 0x0b, 0x06, 0x09, 0x60, 0x86, 0x48, 0x01, 0x65, 0x03,
    0x04, 0x02, 0x04, 0x04, 0x1c
};

static unsigned char sha256_nn_bin[] = {
    0x30, 0x2f, 0x30, 0x0b, 0x06, 0x09, 0x60, 0x86, 0x48, 0x01, 0x65, 0x03,
    0x04, 0x02, 0x01, 0x04, 0x20
};

static unsigned char sha384_nn_bin[] = {
    0x30, 0x3f, 0x30, 0x0b, 0x06, 0x09, 0x60, 0x86, 0x48, 0x01, 0x65, 0x03,
    0x04, 0x02, 0x02, 0x04, 0x30
};

static unsigned char sha512_nn_bin[] = {
    0x30, 0x4f, 0x30, 0x0b, 0x06, 0x09, 0x60, 0x86, 0x48, 0x01, 0x65, 0x03,
    0x04, 0x02, 0x03, 0x04, 0x40
};

static const unsigned char *fips_digestinfo_encoding(int nid,
                                                     unsigned int *len)
{
    switch (nid) {

    case NID_sha1:
        *len = sizeof(sha1_bin);
        return sha1_bin;

    case NID_sha224:
        *len = sizeof(sha224_bin);
        return sha224_bin;

    case NID_sha256:
        *len = sizeof(sha256_bin);
        return sha256_bin;

    case NID_sha384:
        *len = sizeof(sha384_bin);
        return sha384_bin;

    case NID_sha512:
        *len = sizeof(sha512_bin);
        return sha512_bin;

    default:
        return NULL;

    }
}

static const unsigned char *fips_digestinfo_nn_encoding(int nid,
                                                        unsigned int *len)
{
    switch (nid) {

    case NID_sha1:
        *len = sizeof(sha1_nn_bin);
        return sha1_nn_bin;

    case NID_sha224:
        *len = sizeof(sha224_nn_bin);
        return sha224_nn_bin;

    case NID_sha256:
        *len = sizeof(sha256_nn_bin);
        return sha256_nn_bin;

    case NID_sha384:
        *len = sizeof(sha384_nn_bin);
        return sha384_nn_bin;

    case NID_sha512:
        *len = sizeof(sha512_nn_bin);
        return sha512_nn_bin;

    default:
        return NULL;

    }
}

static int fips_rsa_sign(int type, const unsigned char *x, unsigned int y,
                         unsigned char *sigret, unsigned int *siglen,
                         EVP_MD_SVCTX * sv)
{
    int i = 0, j, ret = 0;
    unsigned int dlen;
    const unsigned char *der;
    unsigned int m_len;
    int pad_mode = sv->mctx->flags & EVP_MD_CTX_FLAG_PAD_MASK;
    int rsa_pad_mode = 0;
    RSA *rsa = sv->key;
    /* Largest DigestInfo: 19 (max encoding) + max MD */
    unsigned char tmpdinfo[19 + EVP_MAX_MD_SIZE];
    unsigned char md[EVP_MAX_MD_SIZE + 1];

    EVP_DigestFinal_ex(sv->mctx, md, &m_len);

    if ((rsa->flags & RSA_FLAG_SIGN_VER) && rsa->meth->rsa_sign) {
        ret = rsa->meth->rsa_sign(type, md, m_len, sigret, siglen, rsa);
        goto done;
    }

    if (pad_mode == EVP_MD_CTX_FLAG_PAD_X931) {
        int hash_id;
        memcpy(tmpdinfo, md, m_len);
        hash_id = RSA_X931_hash_id(M_EVP_MD_CTX_type(sv->mctx));
        if (hash_id == -1) {
            RSAerr(RSA_F_FIPS_RSA_SIGN, RSA_R_UNKNOWN_ALGORITHM_TYPE);
            return 0;
        }
        tmpdinfo[m_len] = (unsigned char)hash_id;
        i = m_len + 1;
        rsa_pad_mode = RSA_X931_PADDING;
    } else if (pad_mode == EVP_MD_CTX_FLAG_PAD_PKCS1) {

        der = fips_digestinfo_encoding(type, &dlen);

        if (!der) {
            RSAerr(RSA_F_FIPS_RSA_SIGN, RSA_R_UNKNOWN_ALGORITHM_TYPE);
            return 0;
        }
        memcpy(tmpdinfo, der, dlen);
        memcpy(tmpdinfo + dlen, md, m_len);

        i = dlen + m_len;
        rsa_pad_mode = RSA_PKCS1_PADDING;

    } else if (pad_mode == EVP_MD_CTX_FLAG_PAD_PSS) {
        unsigned char *sbuf;
        int saltlen;
        i = RSA_size(rsa);
        sbuf = OPENSSL_malloc(RSA_size(rsa));
        saltlen = M_EVP_MD_CTX_FLAG_PSS_SALT(sv->mctx);
        if (saltlen == EVP_MD_CTX_FLAG_PSS_MDLEN)
            saltlen = -1;
        else if (saltlen == EVP_MD_CTX_FLAG_PSS_MREC)
            saltlen = -2;
        if (!sbuf) {
            RSAerr(RSA_F_FIPS_RSA_SIGN, ERR_R_MALLOC_FAILURE);
            goto psserr;
        }
        if (!RSA_padding_add_PKCS1_PSS(rsa, sbuf, md,
                                       M_EVP_MD_CTX_md(sv->mctx), saltlen))
            goto psserr;
        j = rsa->meth->rsa_priv_enc(i, sbuf, sigret, rsa, RSA_NO_PADDING);
        if (j > 0) {
            ret = 1;
            *siglen = j;
        }
 psserr:
        OPENSSL_cleanse(md, m_len);
        OPENSSL_cleanse(sbuf, i);
        OPENSSL_free(sbuf);
        return ret;
    }

    j = RSA_size(rsa);
    if (i > (j - RSA_PKCS1_PADDING_SIZE)) {
        RSAerr(RSA_F_FIPS_RSA_SIGN, RSA_R_DIGEST_TOO_BIG_FOR_RSA_KEY);
        goto done;
    }
    /* NB: call underlying method directly to avoid FIPS blocking */
    j = rsa->meth->rsa_priv_enc(i, tmpdinfo, sigret, rsa, rsa_pad_mode);
    if (j > 0) {
        ret = 1;
        *siglen = j;
    }

 done:
    OPENSSL_cleanse(tmpdinfo, i);
    OPENSSL_cleanse(md, m_len);
    return ret;
}

static int fips_rsa_verify(int dtype,
                           const unsigned char *x, unsigned int y,
                           unsigned char *sigbuf, unsigned int siglen,
                           EVP_MD_SVCTX * sv)
{
    int i, ret = 0;
    unsigned int dlen, diglen;
    int pad_mode = sv->mctx->flags & EVP_MD_CTX_FLAG_PAD_MASK;
    int rsa_pad_mode = 0;
    unsigned char *s;
    const unsigned char *der;
    unsigned char dig[EVP_MAX_MD_SIZE];
    RSA *rsa = sv->key;

    if (siglen != (unsigned int)RSA_size(sv->key)) {
        RSAerr(RSA_F_FIPS_RSA_VERIFY, RSA_R_WRONG_SIGNATURE_LENGTH);
        return (0);
    }

    EVP_DigestFinal_ex(sv->mctx, dig, &diglen);

    if ((rsa->flags & RSA_FLAG_SIGN_VER) && rsa->meth->rsa_verify) {
        return rsa->meth->rsa_verify(dtype, dig, diglen, sigbuf, siglen, rsa);
    }

    s = OPENSSL_malloc((unsigned int)siglen);
    if (s == NULL) {
        RSAerr(RSA_F_FIPS_RSA_VERIFY, ERR_R_MALLOC_FAILURE);
        goto err;
    }
    if (pad_mode == EVP_MD_CTX_FLAG_PAD_X931)
        rsa_pad_mode = RSA_X931_PADDING;
    else if (pad_mode == EVP_MD_CTX_FLAG_PAD_PKCS1)
        rsa_pad_mode = RSA_PKCS1_PADDING;
    else if (pad_mode == EVP_MD_CTX_FLAG_PAD_PSS)
        rsa_pad_mode = RSA_NO_PADDING;

    /* NB: call underlying method directly to avoid FIPS blocking */
    i = rsa->meth->rsa_pub_dec((int)siglen, sigbuf, s, rsa, rsa_pad_mode);

    if (i <= 0)
        goto err;

    if (pad_mode == EVP_MD_CTX_FLAG_PAD_X931) {
        int hash_id;
        if (i != (int)(diglen + 1)) {
            RSAerr(RSA_F_FIPS_RSA_VERIFY, RSA_R_BAD_SIGNATURE);
            goto err;
        }
        hash_id = RSA_X931_hash_id(M_EVP_MD_CTX_type(sv->mctx));
        if (hash_id == -1) {
            RSAerr(RSA_F_FIPS_RSA_VERIFY, RSA_R_UNKNOWN_ALGORITHM_TYPE);
            goto err;
        }
        if (s[diglen] != (unsigned char)hash_id) {
            RSAerr(RSA_F_FIPS_RSA_VERIFY, RSA_R_BAD_SIGNATURE);
            goto err;
        }
        if (memcmp(s, dig, diglen)) {
            RSAerr(RSA_F_FIPS_RSA_VERIFY, RSA_R_BAD_SIGNATURE);
            goto err;
        }
        ret = 1;
    } else if (pad_mode == EVP_MD_CTX_FLAG_PAD_PKCS1) {

        der = fips_digestinfo_encoding(dtype, &dlen);

        if (!der) {
            RSAerr(RSA_F_FIPS_RSA_VERIFY, RSA_R_UNKNOWN_ALGORITHM_TYPE);
            return (0);
        }

        /*
         * Compare, DigestInfo length, DigestInfo header and finally digest
         * value itself
         */

        /* If length mismatch try alternate encoding */
        if (i != (int)(dlen + diglen))
            der = fips_digestinfo_nn_encoding(dtype, &dlen);

        if ((i != (int)(dlen + diglen)) || memcmp(der, s, dlen)
            || memcmp(s + dlen, dig, diglen)) {
            RSAerr(RSA_F_FIPS_RSA_VERIFY, RSA_R_BAD_SIGNATURE);
            goto err;
        }
        ret = 1;

    } else if (pad_mode == EVP_MD_CTX_FLAG_PAD_PSS) {
        int saltlen;
        saltlen = M_EVP_MD_CTX_FLAG_PSS_SALT(sv->mctx);
        if (saltlen == EVP_MD_CTX_FLAG_PSS_MDLEN)
            saltlen = -1;
        else if (saltlen == EVP_MD_CTX_FLAG_PSS_MREC)
            saltlen = -2;
        ret = RSA_verify_PKCS1_PSS(rsa, dig, M_EVP_MD_CTX_md(sv->mctx),
                                   s, saltlen);
        if (ret < 0)
            ret = 0;
    }
 err:
    if (s != NULL) {
        OPENSSL_cleanse(s, siglen);
        OPENSSL_free(s);
    }
    return (ret);
}

# define EVP_PKEY_RSA_fips_method \
                                (evp_sign_method *)fips_rsa_sign, \
                                (evp_verify_method *)fips_rsa_verify, \
                                {EVP_PKEY_RSA,EVP_PKEY_RSA2,0,0}

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 sha1_md = {
    NID_sha1,
    NID_sha1WithRSAEncryption,
    SHA_DIGEST_LENGTH,
    EVP_MD_FLAG_FIPS | EVP_MD_FLAG_SVCTX,
    init,
    update,
    final,
    NULL,
    NULL,
    EVP_PKEY_RSA_fips_method,
    SHA_CBLOCK,
    sizeof(EVP_MD *) + sizeof(SHA_CTX),
};

const EVP_MD *EVP_sha1(void)
{
    return (&sha1_md);
}

static int init224(EVP_MD_CTX *ctx)
{
    return SHA224_Init(ctx->md_data);
}

static int init256(EVP_MD_CTX *ctx)
{
    return SHA256_Init(ctx->md_data);
}

/*
 * Even though there're separate SHA224_[Update|Final], we call
 * SHA256 functions even in SHA224 context. This is what happens
 * there anyway, so we can spare few CPU cycles:-)
 */
static int update256(EVP_MD_CTX *ctx, const void *data, size_t count)
{
    return SHA256_Update(ctx->md_data, data, count);
}

static int final256(EVP_MD_CTX *ctx, unsigned char *md)
{
    return SHA256_Final(md, ctx->md_data);
}

static const EVP_MD sha224_md = {
    NID_sha224,
    NID_sha224WithRSAEncryption,
    SHA224_DIGEST_LENGTH,
    EVP_MD_FLAG_FIPS | EVP_MD_FLAG_SVCTX,
    init224,
    update256,
    final256,
    NULL,
    NULL,
    EVP_PKEY_RSA_fips_method,
    SHA256_CBLOCK,
    sizeof(EVP_MD *) + sizeof(SHA256_CTX),
};

const EVP_MD *EVP_sha224(void)
{
    return (&sha224_md);
}

static const EVP_MD sha256_md = {
    NID_sha256,
    NID_sha256WithRSAEncryption,
    SHA256_DIGEST_LENGTH,
    EVP_MD_FLAG_FIPS | EVP_MD_FLAG_SVCTX,
    init256,
    update256,
    final256,
    NULL,
    NULL,
    EVP_PKEY_RSA_fips_method,
    SHA256_CBLOCK,
    sizeof(EVP_MD *) + sizeof(SHA256_CTX),
};

const EVP_MD *EVP_sha256(void)
{
    return (&sha256_md);
}

static int init384(EVP_MD_CTX *ctx)
{
    return SHA384_Init(ctx->md_data);
}

static int init512(EVP_MD_CTX *ctx)
{
    return SHA512_Init(ctx->md_data);
}

/* See comment in SHA224/256 section */
static int update512(EVP_MD_CTX *ctx, const void *data, size_t count)
{
    return SHA512_Update(ctx->md_data, data, count);
}

static int final512(EVP_MD_CTX *ctx, unsigned char *md)
{
    return SHA512_Final(md, ctx->md_data);
}

static const EVP_MD sha384_md = {
    NID_sha384,
    NID_sha384WithRSAEncryption,
    SHA384_DIGEST_LENGTH,
    EVP_MD_FLAG_FIPS | EVP_MD_FLAG_SVCTX,
    init384,
    update512,
    final512,
    NULL,
    NULL,
    EVP_PKEY_RSA_fips_method,
    SHA512_CBLOCK,
    sizeof(EVP_MD *) + sizeof(SHA512_CTX),
};

const EVP_MD *EVP_sha384(void)
{
    return (&sha384_md);
}

static const EVP_MD sha512_md = {
    NID_sha512,
    NID_sha512WithRSAEncryption,
    SHA512_DIGEST_LENGTH,
    EVP_MD_FLAG_FIPS | EVP_MD_FLAG_SVCTX,
    init512,
    update512,
    final512,
    NULL,
    NULL,
    EVP_PKEY_RSA_fips_method,
    SHA512_CBLOCK,
    sizeof(EVP_MD *) + sizeof(SHA512_CTX),
};

const EVP_MD *EVP_sha512(void)
{
    return (&sha512_md);
}

#endif