/* rsa_pss.c */ /* Written by Dr Stephen N Henson (steve@openssl.org) for the OpenSSL * project 2005. */ /* ==================================================================== * Copyright (c) 2005 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 <stdio.h> #include "cryptlib.h" #include <openssl/bn.h> #include <openssl/rsa.h> #include <openssl/evp.h> #include <openssl/rand.h> #include <openssl/sha.h> static const unsigned char zeroes[] = {0,0,0,0,0,0,0,0}; #if defined(_MSC_VER) && defined(_ARM_) #pragma optimize("g", off) #endif int RSA_verify_PKCS1_PSS(RSA *rsa, const unsigned char *mHash, const EVP_MD *Hash, const unsigned char *EM, int sLen) { return RSA_verify_PKCS1_PSS_mgf1(rsa, mHash, Hash, NULL, EM, sLen); } int RSA_verify_PKCS1_PSS_mgf1(RSA *rsa, const unsigned char *mHash, const EVP_MD *Hash, const EVP_MD *mgf1Hash, const unsigned char *EM, int sLen) { int i; int ret = 0; int hLen, maskedDBLen, MSBits, emLen; const unsigned char *H; unsigned char *DB = NULL; EVP_MD_CTX ctx; unsigned char H_[EVP_MAX_MD_SIZE]; EVP_MD_CTX_init(&ctx); if (mgf1Hash == NULL) mgf1Hash = Hash; hLen = EVP_MD_size(Hash); if (hLen < 0) goto err; /* * Negative sLen has special meanings: * -1 sLen == hLen * -2 salt length is autorecovered from signature * -N reserved */ if (sLen == -1) sLen = hLen; else if (sLen == -2) sLen = -2; else if (sLen < -2) { RSAerr(RSA_F_RSA_VERIFY_PKCS1_PSS_MGF1, RSA_R_SLEN_CHECK_FAILED); goto err; } MSBits = (BN_num_bits(rsa->n) - 1) & 0x7; emLen = RSA_size(rsa); if (EM[0] & (0xFF << MSBits)) { RSAerr(RSA_F_RSA_VERIFY_PKCS1_PSS_MGF1, RSA_R_FIRST_OCTET_INVALID); goto err; } if (MSBits == 0) { EM++; emLen--; } if (emLen < (hLen + sLen + 2)) /* sLen can be small negative */ { RSAerr(RSA_F_RSA_VERIFY_PKCS1_PSS_MGF1, RSA_R_DATA_TOO_LARGE); goto err; } if (EM[emLen - 1] != 0xbc) { RSAerr(RSA_F_RSA_VERIFY_PKCS1_PSS_MGF1, RSA_R_LAST_OCTET_INVALID); goto err; } maskedDBLen = emLen - hLen - 1; H = EM + maskedDBLen; DB = OPENSSL_malloc(maskedDBLen); if (!DB) { RSAerr(RSA_F_RSA_VERIFY_PKCS1_PSS_MGF1, ERR_R_MALLOC_FAILURE); goto err; } if (PKCS1_MGF1(DB, maskedDBLen, H, hLen, mgf1Hash) < 0) goto err; for (i = 0; i < maskedDBLen; i++) DB[i] ^= EM[i]; if (MSBits) DB[0] &= 0xFF >> (8 - MSBits); for (i = 0; DB[i] == 0 && i < (maskedDBLen-1); i++) ; if (DB[i++] != 0x1) { RSAerr(RSA_F_RSA_VERIFY_PKCS1_PSS_MGF1, RSA_R_SLEN_RECOVERY_FAILED); goto err; } if (sLen >= 0 && (maskedDBLen - i) != sLen) { RSAerr(RSA_F_RSA_VERIFY_PKCS1_PSS_MGF1, RSA_R_SLEN_CHECK_FAILED); goto err; } if (!EVP_DigestInit_ex(&ctx, Hash, NULL) || !EVP_DigestUpdate(&ctx, zeroes, sizeof zeroes) || !EVP_DigestUpdate(&ctx, mHash, hLen)) goto err; if (maskedDBLen - i) { if (!EVP_DigestUpdate(&ctx, DB + i, maskedDBLen - i)) goto err; } if (!EVP_DigestFinal_ex(&ctx, H_, NULL)) goto err; if (memcmp(H_, H, hLen)) { RSAerr(RSA_F_RSA_VERIFY_PKCS1_PSS_MGF1, RSA_R_BAD_SIGNATURE); ret = 0; } else ret = 1; err: if (DB) OPENSSL_free(DB); EVP_MD_CTX_cleanup(&ctx); return ret; } int RSA_padding_add_PKCS1_PSS(RSA *rsa, unsigned char *EM, const unsigned char *mHash, const EVP_MD *Hash, int sLen) { return RSA_padding_add_PKCS1_PSS_mgf1(rsa, EM, mHash, Hash, NULL, sLen); } int RSA_padding_add_PKCS1_PSS_mgf1(RSA *rsa, unsigned char *EM, const unsigned char *mHash, const EVP_MD *Hash, const EVP_MD *mgf1Hash, int sLen) { int i; int ret = 0; int hLen, maskedDBLen, MSBits, emLen; unsigned char *H, *salt = NULL, *p; EVP_MD_CTX ctx; if (mgf1Hash == NULL) mgf1Hash = Hash; hLen = EVP_MD_size(Hash); if (hLen < 0) goto err; /* * Negative sLen has special meanings: * -1 sLen == hLen * -2 salt length is maximized * -N reserved */ if (sLen == -1) sLen = hLen; else if (sLen == -2) sLen = -2; else if (sLen < -2) { RSAerr(RSA_F_RSA_PADDING_ADD_PKCS1_PSS_MGF1, RSA_R_SLEN_CHECK_FAILED); goto err; } MSBits = (BN_num_bits(rsa->n) - 1) & 0x7; emLen = RSA_size(rsa); if (MSBits == 0) { *EM++ = 0; emLen--; } if (sLen == -2) { sLen = emLen - hLen - 2; } else if (emLen < (hLen + sLen + 2)) { RSAerr(RSA_F_RSA_PADDING_ADD_PKCS1_PSS_MGF1,RSA_R_DATA_TOO_LARGE_FOR_KEY_SIZE); goto err; } if (sLen > 0) { salt = OPENSSL_malloc(sLen); if (!salt) { RSAerr(RSA_F_RSA_PADDING_ADD_PKCS1_PSS_MGF1,ERR_R_MALLOC_FAILURE); goto err; } if (RAND_bytes(salt, sLen) <= 0) goto err; } maskedDBLen = emLen - hLen - 1; H = EM + maskedDBLen; EVP_MD_CTX_init(&ctx); if (!EVP_DigestInit_ex(&ctx, Hash, NULL) || !EVP_DigestUpdate(&ctx, zeroes, sizeof zeroes) || !EVP_DigestUpdate(&ctx, mHash, hLen)) goto err; if (sLen && !EVP_DigestUpdate(&ctx, salt, sLen)) goto err; if (!EVP_DigestFinal_ex(&ctx, H, NULL)) goto err; EVP_MD_CTX_cleanup(&ctx); /* Generate dbMask in place then perform XOR on it */ if (PKCS1_MGF1(EM, maskedDBLen, H, hLen, mgf1Hash)) goto err; p = EM; /* Initial PS XORs with all zeroes which is a NOP so just update * pointer. Note from a test above this value is guaranteed to * be non-negative. */ p += emLen - sLen - hLen - 2; *p++ ^= 0x1; if (sLen > 0) { for (i = 0; i < sLen; i++) *p++ ^= salt[i]; } if (MSBits) EM[0] &= 0xFF >> (8 - MSBits); /* H is already in place so just set final 0xbc */ EM[emLen - 1] = 0xbc; ret = 1; err: if (salt) OPENSSL_free(salt); return ret; } #if defined(_MSC_VER) #pragma optimize("",on) #endif