crypto/rsa/rsa_oaep.c:177: error: INTEGER_OVERFLOW_L2
  ([0, max(0, `flen`)] - 1):unsigned32 by call to `constant_time_is_zero`.
Showing all 5 steps of the trace


crypto/rsa/rsa_oaep.c:116:1: Parameter `flen`
114.   }
115.   
116. > int RSA_padding_check_PKCS1_OAEP_mgf1(unsigned char *to, int tlen,
117.                                         const unsigned char *from, int flen,
118.                                         int num, const unsigned char *param,

crypto/rsa/rsa_oaep.c:177:17: Call
175.        */
176.       for (from += flen, em += num, i = 0; i < num; i++) {
177.           mask = ~constant_time_is_zero(flen);
                       ^
178.           flen -= 1 & mask;
179.           from -= 1 & mask;

include/internal/constant_time_locl.h:164:1: <LHS trace>
162.   }
163.   
164. > static ossl_inline unsigned int constant_time_is_zero(unsigned int a)
165.   {
166.       return constant_time_msb(~a & (a - 1));

include/internal/constant_time_locl.h:164:1: Parameter `a`
  162.   }
  163.   
  164. > static ossl_inline unsigned int constant_time_is_zero(unsigned int a)
  165.   {
  166.       return constant_time_msb(~a & (a - 1));

include/internal/constant_time_locl.h:166:12: Binary operation: ([0, max(0, flen)] - 1):unsigned32 by call to `constant_time_is_zero` 
  164.   static ossl_inline unsigned int constant_time_is_zero(unsigned int a)
  165.   {
  166.       return constant_time_msb(~a & (a - 1));
                    ^
  167.   }
  168.   

static ossl_inline unsigned int constant_time_is_zero(unsigned int a)
{
    return constant_time_msb(~a & (a - 1));
}
['int RSA_padding_check_PKCS1_OAEP_mgf1(unsigned char *to, int tlen,\n                                      const unsigned char *from, int flen,\n                                      int num, const unsigned char *param,\n                                      int plen, const EVP_MD *md,\n                                      const EVP_MD *mgf1md)\n{\n    int i, dblen = 0, mlen = -1, one_index = 0, msg_index;\n    unsigned int good = 0, found_one_byte, mask;\n    const unsigned char *maskedseed, *maskeddb;\n    unsigned char *db = NULL, *em = NULL, seed[EVP_MAX_MD_SIZE],\n        phash[EVP_MAX_MD_SIZE];\n    int mdlen;\n    if (md == NULL)\n        md = EVP_sha1();\n    if (mgf1md == NULL)\n        mgf1md = md;\n    mdlen = EVP_MD_size(md);\n    if (tlen <= 0 || flen <= 0)\n        return -1;\n    if (num < flen || num < 2 * mdlen + 2) {\n        RSAerr(RSA_F_RSA_PADDING_CHECK_PKCS1_OAEP_MGF1,\n               RSA_R_OAEP_DECODING_ERROR);\n        return -1;\n    }\n    dblen = num - mdlen - 1;\n    db = OPENSSL_malloc(dblen);\n    if (db == NULL) {\n        RSAerr(RSA_F_RSA_PADDING_CHECK_PKCS1_OAEP_MGF1, ERR_R_MALLOC_FAILURE);\n        goto cleanup;\n    }\n    em = OPENSSL_malloc(num);\n    if (em == NULL) {\n        RSAerr(RSA_F_RSA_PADDING_CHECK_PKCS1_OAEP_MGF1,\n               ERR_R_MALLOC_FAILURE);\n        goto cleanup;\n    }\n    for (from += flen, em += num, i = 0; i < num; i++) {\n        mask = ~constant_time_is_zero(flen);\n        flen -= 1 & mask;\n        from -= 1 & mask;\n        *--em = *from & mask;\n    }\n    from = em;\n    good = constant_time_is_zero(from[0]);\n    maskedseed = from + 1;\n    maskeddb = from + 1 + mdlen;\n    if (PKCS1_MGF1(seed, mdlen, maskeddb, dblen, mgf1md))\n        goto cleanup;\n    for (i = 0; i < mdlen; i++)\n        seed[i] ^= maskedseed[i];\n    if (PKCS1_MGF1(db, dblen, seed, mdlen, mgf1md))\n        goto cleanup;\n    for (i = 0; i < dblen; i++)\n        db[i] ^= maskeddb[i];\n    if (!EVP_Digest((void *)param, plen, phash, NULL, md, NULL))\n        goto cleanup;\n    good &= constant_time_is_zero(CRYPTO_memcmp(db, phash, mdlen));\n    found_one_byte = 0;\n    for (i = mdlen; i < dblen; i++) {\n        unsigned int equals1 = constant_time_eq(db[i], 1);\n        unsigned int equals0 = constant_time_is_zero(db[i]);\n        one_index = constant_time_select_int(~found_one_byte & equals1,\n                                             i, one_index);\n        found_one_byte |= equals1;\n        good &= (found_one_byte | equals0);\n    }\n    good &= found_one_byte;\n    msg_index = one_index + 1;\n    mlen = dblen - msg_index;\n    good &= constant_time_ge(tlen, mlen);\n    tlen = constant_time_select_int(constant_time_lt(dblen, tlen), dblen, tlen);\n    msg_index = constant_time_select_int(good, msg_index, dblen - tlen);\n    mlen = dblen - msg_index;\n    for (from = db + msg_index, mask = good, i = 0; i < tlen; i++) {\n        unsigned int equals = constant_time_eq(i, mlen);\n        from -= dblen & equals;\n        mask &= mask ^ equals;\n        to[i] = constant_time_select_8(mask, from[i], to[i]);\n    }\n    RSAerr(RSA_F_RSA_PADDING_CHECK_PKCS1_OAEP_MGF1,\n           RSA_R_OAEP_DECODING_ERROR);\n    err_clear_last_constant_time(1 & good);\n cleanup:\n    OPENSSL_cleanse(seed, sizeof(seed));\n    OPENSSL_clear_free(db, dblen);\n    OPENSSL_clear_free(em, num);\n    return constant_time_select_int(good, mlen, -1);\n}', 'static ossl_inline unsigned int constant_time_is_zero(unsigned int a)\n{\n    return constant_time_msb(~a & (a - 1));\n}']