From 169e422edd07d4faf9cc3931dcc738b0b7402fd0 Mon Sep 17 00:00:00 2001 From: Shane Lontis Date: Sun, 22 Dec 2019 09:37:17 +1000 Subject: [PATCH] Remove asn1 module dependency from RSASSA-PKCS1-v1_5 implementation. Replace use of the asn1 module (X509_SIG, X509_ALGOR, ASN1_TYPE, ASN1_OCTET_STRING, i2d_X509_SIG(), etc.) as well as OID lookups using OBJ_nid2obj() with pre-generated DigestInfo encodings for MD2, MD5, MDC-2, SHA-1, SHA-2 and SHA-3; the encoding is selected based on the NID. This is similar to the approach used by the old FOM. Reviewed-by: Richard Levitte Reviewed-by: Tomas Mraz Reviewed-by: Shane Lontis (Merged from https://github.com/openssl/openssl/pull/9138) --- crypto/rsa/rsa_sign.c | 236 +++++++++++++++++++++++++++++++++--------- 1 file changed, 186 insertions(+), 50 deletions(-) diff --git a/crypto/rsa/rsa_sign.c b/crypto/rsa/rsa_sign.c index 0ed9acf431..6479d12684 100644 --- a/crypto/rsa/rsa_sign.c +++ b/crypto/rsa/rsa_sign.c @@ -1,5 +1,5 @@ /* - * Copyright 1995-2016 The OpenSSL Project Authors. All Rights Reserved. + * Copyright 1995-2019 The OpenSSL Project Authors. All Rights Reserved. * * Licensed under the Apache License 2.0 (the "License"). You may not use * this file except in compliance with the License. You can obtain a copy @@ -14,68 +14,199 @@ #include #include #include "crypto/x509.h" +#ifndef OPENSSL_NO_MD2 +# include /* uses MD2_DIGEST_LENGTH */ +#endif +#ifndef OPENSSL_NO_MD5 +# include /* uses MD5_DIGEST_LENGTH */ +#endif +#ifndef OPENSSL_NO_MDC2 +# include /* uses MDC2_DIGEST_LENGTH */ +#endif +#include /* uses SHA???_DIGEST_LENGTH */ #include "rsa_local.h" +/* + * The general purpose ASN1 code is not available inside the FIPS provider. + * To remove the dependency RSASSA-PKCS1-v1_5 DigestInfo encodings can be + * treated as a special case by pregenerating the required ASN1 encoding. + * This encoding will also be shared by the default provider. + * + * The EMSA-PKCS1-v1_5 encoding method includes an ASN.1 value of type + * DigestInfo, where the type DigestInfo has the syntax + * + * DigestInfo ::= SEQUENCE { + * digestAlgorithm DigestAlgorithm, + * digest OCTET STRING + * } + * + * DigestAlgorithm ::= AlgorithmIdentifier { + * {PKCS1-v1-5DigestAlgorithms} + * } + * + * The AlgorithmIdentifier is a sequence containing the digest OID and + * parameters (a value of type NULL). + * + * The ENCODE_DIGESTINFO_SHA() and ENCODE_DIGESTINFO_MD() macros define an + * initialized array containing the DER encoded DigestInfo for the specified + * SHA or MD digest. The content of the OCTET STRING is not included. + * |name| is the digest name. + * |n| is last byte in the encoded OID for the digest. + * |sz| is the digest length in bytes. It must not be greater than 110. + */ + +#define ASN1_SEQUENCE 0x30 +#define ASN1_OCTET_STRING 0x04 +#define ASN1_NULL 0x05 +#define ASN1_OID 0x06 + +/* SHA OIDs are of the form: (2 16 840 1 101 3 4 2 |n|) */ +#define ENCODE_DIGESTINFO_SHA(name, n, sz) \ +static const unsigned char digestinfo_##name##_der[] = { \ + ASN1_SEQUENCE, 0x11 + sz, \ + ASN1_SEQUENCE, 0x0d, \ + ASN1_OID, 0x09, 2 * 40 + 16, 0x86, 0x48, 1, 101, 3, 4, 2, n, \ + ASN1_NULL, 0x00, \ + ASN1_OCTET_STRING, sz \ +}; + +/* MD2 and MD5 OIDs are of the form: (1 2 840 113549 2 |n|) */ +#define ENCODE_DIGESTINFO_MD(name, n, sz) \ +static const unsigned char digestinfo_##name##_der[] = { \ + ASN1_SEQUENCE, 0x10 + sz, \ + ASN1_SEQUENCE, 0x0c, \ + ASN1_OID, 0x08, 1 * 40 + 2, 0x86, 0x48, 0x86, 0xf7, 0x0d, 2, n, \ + ASN1_NULL, 0x00, \ + ASN1_OCTET_STRING, sz \ +}; + +#ifndef FIPS_MODE +# ifndef OPENSSL_NO_MD2 +ENCODE_DIGESTINFO_MD(md2, 0x02, MD2_DIGEST_LENGTH) +# endif +# ifndef OPENSSL_NO_MD5 +ENCODE_DIGESTINFO_MD(md5, 0x05, MD5_DIGEST_LENGTH) +# endif +# ifndef OPENSSL_NO_MDC2 +/* MDC-2 (2 5 8 3 101) */ +static const unsigned char digestinfo_mdc2_der[] = { + ASN1_SEQUENCE, 0x0c + MDC2_DIGEST_LENGTH, + ASN1_SEQUENCE, 0x08, + ASN1_OID, 0x04, 2 * 40 + 5, 8, 3, 101, + ASN1_NULL, 0x00, + ASN1_OCTET_STRING, MDC2_DIGEST_LENGTH +}; +# endif +/* SHA-1 (1 3 14 3 2 26) */ +static const unsigned char digestinfo_sha1_der[] = { + ASN1_SEQUENCE, 0x0d + SHA_DIGEST_LENGTH, + ASN1_SEQUENCE, 0x09, + ASN1_OID, 0x05, 1 * 40 + 3, 14, 3, 2, 26, + ASN1_NULL, 0x00, + ASN1_OCTET_STRING, SHA_DIGEST_LENGTH +}; + +#endif /* FIPS_MODE */ + +ENCODE_DIGESTINFO_SHA(sha256, 0x01, SHA256_DIGEST_LENGTH) +ENCODE_DIGESTINFO_SHA(sha384, 0x02, SHA384_DIGEST_LENGTH) +ENCODE_DIGESTINFO_SHA(sha512, 0x03, SHA512_DIGEST_LENGTH) +ENCODE_DIGESTINFO_SHA(sha224, 0x04, SHA224_DIGEST_LENGTH) +ENCODE_DIGESTINFO_SHA(sha512_224, 0x05, SHA224_DIGEST_LENGTH) +ENCODE_DIGESTINFO_SHA(sha512_256, 0x06, SHA256_DIGEST_LENGTH) +ENCODE_DIGESTINFO_SHA(sha3_224, 0x07, SHA224_DIGEST_LENGTH) +ENCODE_DIGESTINFO_SHA(sha3_256, 0x08, SHA256_DIGEST_LENGTH) +ENCODE_DIGESTINFO_SHA(sha3_384, 0x09, SHA384_DIGEST_LENGTH) +ENCODE_DIGESTINFO_SHA(sha3_512, 0x0a, SHA512_DIGEST_LENGTH) + +#define MD_CASE(name) \ + case NID_##name: \ + *len = sizeof(digestinfo_##name##_der); \ + return digestinfo_##name##_der; + +static const unsigned char *digestinfo_encoding(int nid, size_t *len) +{ + switch (nid) { +#ifndef FIPS_MODE +# ifndef OPENSSL_NO_MDC2 + MD_CASE(mdc2) +# endif +# ifndef OPENSSL_NO_MD2 + MD_CASE(md2) +# endif +# ifndef OPENSSL_NO_MD5 + MD_CASE(md5) +# endif + MD_CASE(sha1) +#endif /* FIPS_MODE */ + MD_CASE(sha224) + MD_CASE(sha256) + MD_CASE(sha384) + MD_CASE(sha512) + MD_CASE(sha512_224) + MD_CASE(sha512_256) + MD_CASE(sha3_224) + MD_CASE(sha3_256) + MD_CASE(sha3_384) + MD_CASE(sha3_512) + default: + return NULL; + } +} + /* Size of an SSL signature: MD5+SHA1 */ #define SSL_SIG_LENGTH 36 /* - * encode_pkcs1 encodes a DigestInfo prefix of hash |type| and digest |m|, as + * 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. + * |*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) +static int encode_pkcs1(unsigned char **out, size_t *out_len, int type, + const unsigned char *m, size_t m_len) { - X509_SIG sig; - X509_ALGOR algor; - ASN1_TYPE parameter; - ASN1_OCTET_STRING digest; - uint8_t *der = NULL; - int len; - - sig.algor = &algor; - sig.algor->algorithm = OBJ_nid2obj(type); - if (sig.algor->algorithm == NULL) { + size_t di_prefix_len, dig_info_len; + const unsigned char *di_prefix; + unsigned char *dig_info; + + if (type == NID_undef) { RSAerr(RSA_F_ENCODE_PKCS1, RSA_R_UNKNOWN_ALGORITHM_TYPE); return 0; } - if (OBJ_length(sig.algor->algorithm) == 0) { + di_prefix = digestinfo_encoding(type, &di_prefix_len); + if (di_prefix == NULL) { RSAerr(RSA_F_ENCODE_PKCS1, 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; - sig.digest->length = m_len; - - len = i2d_X509_SIG(&sig, &der); - if (len < 0) + dig_info_len = di_prefix_len + m_len; + dig_info = OPENSSL_malloc(dig_info_len); + if (dig_info == NULL) { + RSAerr(RSA_F_ENCODE_PKCS1, ERR_R_MALLOC_FAILURE); return 0; + } + memcpy(dig_info, di_prefix, di_prefix_len); + memcpy(dig_info + di_prefix_len, m, m_len); - *out = der; - *out_len = len; + *out = dig_info; + *out_len = dig_info_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; + int encrypt_len, ret = 0; + size_t encoded_len = 0; unsigned char *tmps = NULL; const unsigned char *encoded = NULL; - if (rsa->meth->rsa_sign) { + if (rsa->meth->rsa_sign != NULL) return rsa->meth->rsa_sign(type, m, m_len, sigret, siglen, rsa); - } /* Compute the encoded digest. */ if (type == NID_md5_sha1) { @@ -96,11 +227,11 @@ int RSA_sign(int type, const unsigned char *m, unsigned int m_len, encoded = tmps; } - if (encoded_len > RSA_size(rsa) - RSA_PKCS1_PADDING_SIZE) { + if (encoded_len + RSA_PKCS1_PADDING_SIZE > (size_t)RSA_size(rsa)) { RSAerr(RSA_F_RSA_SIGN, RSA_R_DIGEST_TOO_BIG_FOR_RSA_KEY); goto err; } - encrypt_len = RSA_private_encrypt(encoded_len, encoded, sigret, rsa, + encrypt_len = RSA_private_encrypt((int)encoded_len, encoded, sigret, rsa, RSA_PKCS1_PADDING); if (encrypt_len <= 0) goto err; @@ -109,23 +240,25 @@ int RSA_sign(int type, const unsigned char *m, unsigned int m_len, ret = 1; err: - OPENSSL_clear_free(tmps, (size_t)encoded_len); + OPENSSL_clear_free(tmps, encoded_len); return ret; } /* - * 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. + * Verify an RSA signature in |sigbuf| using |rsa|. + * |type| is the NID of the digest algorithm to use. + * 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|. + * + * It returns one on successful verification or 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 decrypt_len, ret = 0, encoded_len = 0; + int len, ret = 0; + size_t decrypt_len, encoded_len = 0; unsigned char *decrypt_buf = NULL, *encoded = NULL; if (siglen != (size_t)RSA_size(rsa)) { @@ -140,10 +273,11 @@ int int_rsa_verify(int type, const unsigned char *m, unsigned int m_len, goto err; } - decrypt_len = RSA_public_decrypt((int)siglen, sigbuf, decrypt_buf, rsa, - RSA_PKCS1_PADDING); - if (decrypt_len <= 0) + len = RSA_public_decrypt((int)siglen, sigbuf, decrypt_buf, rsa, + RSA_PKCS1_PADDING); + if (len <= 0) goto err; + decrypt_len = len; if (type == NID_md5_sha1) { /* @@ -203,8 +337,11 @@ int int_rsa_verify(int type, const unsigned char *m, unsigned int m_len, goto err; } - m_len = EVP_MD_size(md); - if (m_len > (size_t)decrypt_len) { + len = EVP_MD_size(md); + if (len <= 0) + goto err; + m_len = (unsigned int)len; + if (m_len > decrypt_len) { RSAerr(RSA_F_INT_RSA_VERIFY, RSA_R_INVALID_DIGEST_LENGTH); goto err; } @@ -216,7 +353,7 @@ int int_rsa_verify(int type, const unsigned char *m, unsigned int m_len, goto err; if (encoded_len != decrypt_len - || memcmp(encoded, decrypt_buf, encoded_len) != 0) { + || memcmp(encoded, decrypt_buf, encoded_len) != 0) { RSAerr(RSA_F_INT_RSA_VERIFY, RSA_R_BAD_SIGNATURE); goto err; } @@ -231,7 +368,7 @@ int int_rsa_verify(int type, const unsigned char *m, unsigned int m_len, ret = 1; err: - OPENSSL_clear_free(encoded, (size_t)encoded_len); + OPENSSL_clear_free(encoded, encoded_len); OPENSSL_clear_free(decrypt_buf, siglen); return ret; } @@ -240,9 +377,8 @@ int RSA_verify(int type, const unsigned char *m, unsigned int m_len, const unsigned char *sigbuf, unsigned int siglen, RSA *rsa) { - if (rsa->meth->rsa_verify) { + if (rsa->meth->rsa_verify != NULL) return rsa->meth->rsa_verify(type, m, m_len, sigbuf, siglen, rsa); - } return int_rsa_verify(type, m, m_len, NULL, NULL, sigbuf, siglen, rsa); } -- 2.25.1