diff options
Diffstat (limited to 'crypto/rsa/rsa_sign.c')
-rw-r--r-- | crypto/rsa/rsa_sign.c | 413 |
1 files changed, 180 insertions, 233 deletions
diff --git a/crypto/rsa/rsa_sign.c b/crypto/rsa/rsa_sign.c index 82ca8324dfbc..952d24fb8ae4 100644 --- a/crypto/rsa/rsa_sign.c +++ b/crypto/rsa/rsa_sign.c @@ -1,301 +1,248 @@ -/* crypto/rsa/rsa_sign.c */ -/* 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. +/* + * Copyright 1995-2016 The OpenSSL Project Authors. All Rights Reserved. * - * 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.] + * Licensed under the OpenSSL license (the "License"). You may not use + * this file except in compliance with the License. You can obtain a copy + * in the file LICENSE in the source distribution or at + * https://www.openssl.org/source/license.html */ #include <stdio.h> -#include "cryptlib.h" +#include "internal/cryptlib.h" #include <openssl/bn.h> #include <openssl/rsa.h> #include <openssl/objects.h> #include <openssl/x509.h> +#include "internal/x509_int.h" #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) +/* + * encode_pkcs1 encodes a DigestInfo prefix of hash |type| and digest |m|, as + * described in EMSA-PKCS1-v1_5-ENCODE, RFC 3447 section 9.2 step 2. This + * encodes the DigestInfo (T and tLen) but does not add the padding. + * + * On success, it returns one and sets |*out| to a newly allocated buffer + * containing the result and |*out_len| to its length. The caller must free + * |*out| with |OPENSSL_free|. Otherwise, it returns zero. + */ +static int encode_pkcs1(unsigned char **out, int *out_len, int type, + const unsigned char *m, unsigned int m_len) { 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_TYPE parameter; ASN1_OCTET_STRING digest; -#ifdef OPENSSL_FIPS - if (FIPS_mode() && !(rsa->meth->flags & RSA_FLAG_FIPS_METHOD) - && !(rsa->flags & RSA_FLAG_NON_FIPS_ALLOW)) { - RSAerr(RSA_F_RSA_SIGN, RSA_R_NON_FIPS_RSA_METHOD); + uint8_t *der = NULL; + int len; + + sig.algor = &algor; + sig.algor->algorithm = OBJ_nid2obj(type); + if (sig.algor->algorithm == NULL) { + RSAerr(RSA_F_ENCODE_PKCS1, RSA_R_UNKNOWN_ALGORITHM_TYPE); + return 0; + } + if (OBJ_length(sig.algor->algorithm) == 0) { + RSAerr(RSA_F_ENCODE_PKCS1, + RSA_R_THE_ASN1_OBJECT_IDENTIFIER_IS_NOT_KNOWN_FOR_THIS_MD); return 0; } -#endif - if ((rsa->flags & RSA_FLAG_SIGN_VER) && rsa->meth->rsa_sign) { + parameter.type = V_ASN1_NULL; + parameter.value.ptr = NULL; + sig.algor->parameter = ¶meter; + + sig.digest = &digest; + sig.digest->data = (unsigned char *)m; + sig.digest->length = m_len; + + len = i2d_X509_SIG(&sig, &der); + if (len < 0) + return 0; + + *out = der; + *out_len = len; + return 1; +} + +int RSA_sign(int type, const unsigned char *m, unsigned int m_len, + unsigned char *sigret, unsigned int *siglen, RSA *rsa) +{ + int encrypt_len, encoded_len = 0, ret = 0; + unsigned char *tmps = NULL; + const unsigned char *encoded = NULL; + + if (rsa->meth->rsa_sign) { return rsa->meth->rsa_sign(type, m, m_len, sigret, siglen, rsa); } - /* Special case: SSL signature, just check the length */ + + /* Compute the encoded digest. */ if (type == NID_md5_sha1) { + /* + * NID_md5_sha1 corresponds to the MD5/SHA1 combination in TLS 1.1 and + * earlier. It has no DigestInfo wrapper but otherwise is + * RSASSA-PKCS1-v1_5. + */ if (m_len != SSL_SIG_LENGTH) { RSAerr(RSA_F_RSA_SIGN, RSA_R_INVALID_MESSAGE_LENGTH); - return (0); + return 0; } - i = SSL_SIG_LENGTH; - s = m; + encoded_len = SSL_SIG_LENGTH; + encoded = 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); + if (!encode_pkcs1(&tmps, &encoded_len, type, m, m_len)) + goto err; + encoded = tmps; } - j = RSA_size(rsa); - if (i > (j - RSA_PKCS1_PADDING_SIZE)) { + + if (encoded_len > RSA_size(rsa) - 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 = (unsigned char *)OPENSSL_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; + goto err; } - i = RSA_private_encrypt(i, s, sigret, rsa, RSA_PKCS1_PADDING); - if (i <= 0) - ret = 0; - else - *siglen = i; + encrypt_len = RSA_private_encrypt(encoded_len, encoded, sigret, rsa, + RSA_PKCS1_PADDING); + if (encrypt_len <= 0) + goto err; - if (type != NID_md5_sha1) { - OPENSSL_cleanse(tmps, (unsigned int)j + 1); - OPENSSL_free(tmps); - } - return (ret); -} + *siglen = encrypt_len; + ret = 1; -/* - * Check DigestInfo structure does not contain extraneous data by reencoding - * using DER and checking encoding against original. - */ -static int rsa_check_digestinfo(X509_SIG *sig, const unsigned char *dinfo, - int dinfolen) -{ - unsigned char *der = NULL; - int derlen; - int ret = 0; - derlen = i2d_X509_SIG(sig, &der); - if (derlen <= 0) - return 0; - if (derlen == dinfolen && !memcmp(dinfo, der, derlen)) - ret = 1; - OPENSSL_cleanse(der, derlen); - OPENSSL_free(der); +err: + OPENSSL_clear_free(tmps, (size_t)encoded_len); return ret; } -int int_rsa_verify(int dtype, const unsigned char *m, - unsigned int m_len, +/* + * int_rsa_verify verifies an RSA signature in |sigbuf| using |rsa|. It may be + * called in two modes. If |rm| is NULL, it verifies the signature for digest + * |m|. Otherwise, it recovers the digest from the signature, writing the digest + * to |rm| and the length to |*prm_len|. |type| is the NID of the digest + * algorithm to use. It returns one on successful verification and zero + * otherwise. + */ +int int_rsa_verify(int type, 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; + int decrypt_len, ret = 0, encoded_len = 0; + unsigned char *decrypt_buf = NULL, *encoded = NULL; -#ifdef OPENSSL_FIPS - if (FIPS_mode() && !(rsa->meth->flags & RSA_FLAG_FIPS_METHOD) - && !(rsa->flags & RSA_FLAG_NON_FIPS_ALLOW)) { - RSAerr(RSA_F_INT_RSA_VERIFY, RSA_R_NON_FIPS_RSA_METHOD); - return 0; - } -#endif - - if (siglen != (unsigned int)RSA_size(rsa)) { + if (siglen != (size_t)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; + return 0; } - s = (unsigned char *)OPENSSL_malloc((unsigned int)siglen); - if (s == NULL) { + /* Recover the encoded digest. */ + decrypt_buf = OPENSSL_malloc(siglen); + if (decrypt_buf == 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) + decrypt_len = RSA_public_decrypt((int)siglen, sigbuf, decrypt_buf, rsa, + RSA_PKCS1_PADDING); + if (decrypt_len <= 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)) { + + if (type == NID_md5_sha1) { + /* + * NID_md5_sha1 corresponds to the MD5/SHA1 combination in TLS 1.1 and + * earlier. It has no DigestInfo wrapper but otherwise is + * RSASSA-PKCS1-v1_5. + */ + if (decrypt_len != SSL_SIG_LENGTH) { RSAerr(RSA_F_INT_RSA_VERIFY, RSA_R_BAD_SIGNATURE); - } else { - ret = 1; + goto err; } - } else if (dtype == NID_md5_sha1) { - /* Special case: SSL signature */ - 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; + if (rm != NULL) { + memcpy(rm, decrypt_buf, SSL_SIG_LENGTH); + *prm_len = SSL_SIG_LENGTH; + } else { + if (m_len != SSL_SIG_LENGTH) { + RSAerr(RSA_F_INT_RSA_VERIFY, RSA_R_INVALID_MESSAGE_LENGTH); + goto err; + } - /* Excess data can be used to create forgeries */ - if (p != s + i || !rsa_check_digestinfo(sig, s, i)) { - RSAerr(RSA_F_INT_RSA_VERIFY, RSA_R_BAD_SIGNATURE); - goto err; + if (memcmp(decrypt_buf, m, SSL_SIG_LENGTH) != 0) { + RSAerr(RSA_F_INT_RSA_VERIFY, RSA_R_BAD_SIGNATURE); + goto err; + } } + } else if (type == NID_mdc2 && decrypt_len == 2 + 16 + && decrypt_buf[0] == 0x04 && decrypt_buf[1] == 0x10) { + /* + * Oddball MDC2 case: signature can be OCTET STRING. check for correct + * tag and length octets. + */ + if (rm != NULL) { + memcpy(rm, decrypt_buf + 2, 16); + *prm_len = 16; + } else { + if (m_len != 16) { + RSAerr(RSA_F_INT_RSA_VERIFY, RSA_R_INVALID_MESSAGE_LENGTH); + goto err; + } + if (memcmp(m, decrypt_buf + 2, 16) != 0) { + RSAerr(RSA_F_INT_RSA_VERIFY, RSA_R_BAD_SIGNATURE); + goto err; + } + } + } else { /* - * Parameters to the signature algorithm can also be used to create - * forgeries + * If recovering the digest, extract a digest-sized output from the end + * of |decrypt_buf| for |encode_pkcs1|, then compare the decryption + * output as in a standard verification. */ - 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; + if (rm != NULL) { + const EVP_MD *md = EVP_get_digestbynid(type); + if (md == NULL) { + RSAerr(RSA_F_INT_RSA_VERIFY, RSA_R_UNKNOWN_ALGORITHM_TYPE); + goto err; + } + + m_len = EVP_MD_size(md); + if (m_len > (size_t)decrypt_len) { + RSAerr(RSA_F_INT_RSA_VERIFY, RSA_R_INVALID_DIGEST_LENGTH); + goto err; + } + m = decrypt_buf + decrypt_len - m_len; } - sigtype = OBJ_obj2nid(sig->algor->algorithm); + /* Construct the encoded digest and ensure it matches. */ + if (!encode_pkcs1(&encoded, &encoded_len, type, m, m_len)) + goto err; -#ifdef RSA_DEBUG - /* put a backward compatibility flag in EAY */ - fprintf(stderr, "in(%s) expect(%s)\n", OBJ_nid2ln(sigtype), - OBJ_nid2ln(dtype)); -#endif - if (sigtype != dtype) { - RSAerr(RSA_F_INT_RSA_VERIFY, RSA_R_ALGORITHM_MISMATCH); + if (encoded_len != decrypt_len + || memcmp(encoded, decrypt_buf, encoded_len) != 0) { + RSAerr(RSA_F_INT_RSA_VERIFY, RSA_R_BAD_SIGNATURE); 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); - OPENSSL_free(s); + + /* Output the recovered digest. */ + if (rm != NULL) { + memcpy(rm, m, m_len); + *prm_len = m_len; + } } - return (ret); + + ret = 1; + +err: + OPENSSL_clear_free(encoded, (size_t)encoded_len); + OPENSSL_clear_free(decrypt_buf, siglen); + return ret; } -int RSA_verify(int dtype, const unsigned char *m, unsigned int m_len, +int RSA_verify(int type, 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); + if (rsa->meth->rsa_verify) { + return rsa->meth->rsa_verify(type, m, m_len, sigbuf, siglen, rsa); } - return int_rsa_verify(dtype, m, m_len, NULL, NULL, sigbuf, siglen, rsa); + return int_rsa_verify(type, m, m_len, NULL, NULL, sigbuf, siglen, rsa); } |