/* $OpenBSD: rsa_sign.c,v 1.21 2014/07/10 13:58:23 jsing Exp $ */ /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com) * All rights reserved. * * This package is an SSL implementation written * by Eric Young (eay@cryptsoft.com). * The implementation was written so as to conform with Netscapes SSL. * * This library is free for commercial and non-commercial use as long as * the following conditions are aheared to. The following conditions * apply to all code found in this distribution, be it the RC4, RSA, * lhash, DES, etc., code; not just the SSL code. The SSL documentation * included with this distribution is covered by the same copyright terms * except that the holder is Tim Hudson (tjh@cryptsoft.com). * * Copyright remains Eric Young's, and as such any Copyright notices in * the code are not to be removed. * If this package is used in a product, Eric Young should be given attribution * as the author of the parts of the library used. * This can be in the form of a textual message at program startup or * in documentation (online or textual) provided with the package. * * 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 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 acknowledgement: * "This product includes cryptographic software written by * Eric Young (eay@cryptsoft.com)" * The word 'cryptographic' can be left out if the rouines from the library * being used are not cryptographic related :-). * 4. If you include any Windows specific code (or a derivative thereof) from * the apps directory (application code) you must include an acknowledgement: * "This product includes software written by Tim Hudson (tjh@cryptsoft.com)" * * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND * ANY EXPRESS 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 AUTHOR OR 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. * * The licence and distribution terms for any publically available version or * derivative of this code cannot be changed. i.e. this code cannot simply be * copied and put under another distribution licence * [including the GNU Public Licence.] */ #include #include #include #include #include #include #include #include "rsa_locl.h" /* Size of an SSL signature: MD5+SHA1 */ #define SSL_SIG_LENGTH 36 int RSA_sign(int type, const unsigned char *m, unsigned int m_len, unsigned char *sigret, unsigned int *siglen, RSA *rsa) { X509_SIG sig; ASN1_TYPE parameter; int i, j, ret = 1; unsigned char *p, *tmps = NULL; const unsigned char *s = NULL; X509_ALGOR algor; ASN1_OCTET_STRING digest; if ((rsa->flags & RSA_FLAG_SIGN_VER) && rsa->meth->rsa_sign) return rsa->meth->rsa_sign(type, m, m_len, sigret, siglen, rsa); /* Special case: SSL signature, just check the length */ if (type == NID_md5_sha1) { if (m_len != SSL_SIG_LENGTH) { RSAerr(RSA_F_RSA_SIGN, RSA_R_INVALID_MESSAGE_LENGTH); return 0; } i = SSL_SIG_LENGTH; s = m; } else { sig.algor = &algor; sig.algor->algorithm = OBJ_nid2obj(type); if (sig.algor->algorithm == NULL) { RSAerr(RSA_F_RSA_SIGN, RSA_R_UNKNOWN_ALGORITHM_TYPE); return 0; } if (sig.algor->algorithm->length == 0) { RSAerr(RSA_F_RSA_SIGN, RSA_R_THE_ASN1_OBJECT_IDENTIFIER_IS_NOT_KNOWN_FOR_THIS_MD); return 0; } parameter.type = V_ASN1_NULL; parameter.value.ptr = NULL; sig.algor->parameter = ¶meter; sig.digest = &digest; sig.digest->data = (unsigned char *)m; /* TMP UGLY CAST */ sig.digest->length = m_len; i = i2d_X509_SIG(&sig, NULL); } j = RSA_size(rsa); if (i > j - RSA_PKCS1_PADDING_SIZE) { RSAerr(RSA_F_RSA_SIGN, RSA_R_DIGEST_TOO_BIG_FOR_RSA_KEY); return 0; } if (type != NID_md5_sha1) { tmps = malloc((unsigned int)j + 1); if (tmps == NULL) { RSAerr(RSA_F_RSA_SIGN, ERR_R_MALLOC_FAILURE); return 0; } p = tmps; i2d_X509_SIG(&sig, &p); s = tmps; } i = RSA_private_encrypt(i, s, sigret, rsa, RSA_PKCS1_PADDING); if (i <= 0) ret = 0; else *siglen = i; if (type != NID_md5_sha1) { OPENSSL_cleanse(tmps, (unsigned int)j + 1); free(tmps); } return (ret); } int int_rsa_verify(int dtype, const unsigned char *m, unsigned int m_len, unsigned char *rm, size_t *prm_len, const unsigned char *sigbuf, size_t siglen, RSA *rsa) { int i, ret = 0, sigtype; unsigned char *s; X509_SIG *sig = NULL; if (siglen != (unsigned int)RSA_size(rsa)) { RSAerr(RSA_F_INT_RSA_VERIFY, RSA_R_WRONG_SIGNATURE_LENGTH); return 0; } if ((dtype == NID_md5_sha1) && rm) { i = RSA_public_decrypt((int)siglen, sigbuf, rm, rsa, RSA_PKCS1_PADDING); if (i <= 0) return 0; *prm_len = i; return 1; } s = malloc((unsigned int)siglen); if (s == NULL) { RSAerr(RSA_F_INT_RSA_VERIFY, ERR_R_MALLOC_FAILURE); goto err; } if (dtype == NID_md5_sha1 && m_len != SSL_SIG_LENGTH) { RSAerr(RSA_F_INT_RSA_VERIFY, RSA_R_INVALID_MESSAGE_LENGTH); goto err; } i = RSA_public_decrypt((int)siglen, sigbuf, s, rsa, RSA_PKCS1_PADDING); if (i <= 0) goto err; /* * Oddball MDC2 case: signature can be OCTET STRING. * check for correct tag and length octets. */ if (dtype == NID_mdc2 && i == 18 && s[0] == 0x04 && s[1] == 0x10) { if (rm) { memcpy(rm, s + 2, 16); *prm_len = 16; ret = 1; } else if (memcmp(m, s + 2, 16)) RSAerr(RSA_F_INT_RSA_VERIFY, RSA_R_BAD_SIGNATURE); else ret = 1; } /* Special case: SSL signature */ if (dtype == NID_md5_sha1) { if (i != SSL_SIG_LENGTH || memcmp(s, m, SSL_SIG_LENGTH)) RSAerr(RSA_F_INT_RSA_VERIFY, RSA_R_BAD_SIGNATURE); else ret = 1; } else { const unsigned char *p = s; sig = d2i_X509_SIG(NULL, &p, (long)i); if (sig == NULL) goto err; /* Excess data can be used to create forgeries */ if (p != s + i) { RSAerr(RSA_F_INT_RSA_VERIFY, RSA_R_BAD_SIGNATURE); goto err; } /* Parameters to the signature algorithm can also be used to create forgeries */ if (sig->algor->parameter && ASN1_TYPE_get(sig->algor->parameter) != V_ASN1_NULL) { RSAerr(RSA_F_INT_RSA_VERIFY, RSA_R_BAD_SIGNATURE); goto err; } sigtype = OBJ_obj2nid(sig->algor->algorithm); if (sigtype != dtype) { RSAerr(RSA_F_INT_RSA_VERIFY, RSA_R_ALGORITHM_MISMATCH); goto err; } if (rm) { const EVP_MD *md; md = EVP_get_digestbynid(dtype); if (md && (EVP_MD_size(md) != sig->digest->length)) RSAerr(RSA_F_INT_RSA_VERIFY, RSA_R_INVALID_DIGEST_LENGTH); else { memcpy(rm, sig->digest->data, sig->digest->length); *prm_len = sig->digest->length; ret = 1; } } else if ((unsigned int)sig->digest->length != m_len || memcmp(m, sig->digest->data, m_len) != 0) { RSAerr(RSA_F_INT_RSA_VERIFY, RSA_R_BAD_SIGNATURE); } else ret = 1; } err: if (sig != NULL) X509_SIG_free(sig); if (s != NULL) { OPENSSL_cleanse(s, (unsigned int)siglen); free(s); } return ret; } int RSA_verify(int dtype, const unsigned char *m, unsigned int m_len, const unsigned char *sigbuf, unsigned int siglen, RSA *rsa) { if ((rsa->flags & RSA_FLAG_SIGN_VER) && rsa->meth->rsa_verify) return rsa->meth->rsa_verify(dtype, m, m_len, sigbuf, siglen, rsa); return int_rsa_verify(dtype, m, m_len, NULL, NULL, sigbuf, siglen, rsa); }