crypto/rsa/rsa_oaep.c:190: error: INTEGER_OVERFLOW_L2
  ([0, +oo] - 1):unsigned32 by call to `constant_time_is_zero`.
Showing all 7 steps of the trace


crypto/rsa/rsa_oaep.c:190:35: Call
188.           goto cleanup;
189.   
190.       good &= constant_time_is_zero(CRYPTO_memcmp(db, phash, mdlen));
                                         ^
191.   
192.       found_one_byte = 0;

crypto/cryptlib.c:475:5: Assignment
  473.       const volatile unsigned char *a = in_a;
  474.       const volatile unsigned char *b = in_b;
  475.       unsigned char x = 0;
             ^
  476.   
  477.       for (i = 0; i < len; i++)

crypto/cryptlib.c:480:5: Assignment
  478.           x |= a[i] ^ b[i];
  479.   
  480.       return x;
             ^
  481.   }

crypto/rsa/rsa_oaep.c:190:13: Call
188.           goto cleanup;
189.   
190.       good &= constant_time_is_zero(CRYPTO_memcmp(db, phash, mdlen));
                   ^
191.   
192.       found_one_byte = 0;

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

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

include/internal/constant_time_locl.h:167:12: Binary operation: ([0, +oo] - 1):unsigned32 by call to `constant_time_is_zero` 
  165.   static ossl_inline unsigned int constant_time_is_zero(unsigned int a)
  166.   {
  167.       return constant_time_msb(~a & (a - 1));
                    ^
  168.   }
  169.   

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, mlen = -1, one_index = 0, msg_index;\n    unsigned int good, found_one_byte;\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        goto decoding_err;\n    dblen = num - mdlen - 1;\n    db = OPENSSL_malloc(dblen);\n    em = OPENSSL_malloc(num);\n    if (db == NULL || em == NULL) {\n        RSAerr(RSA_F_RSA_PADDING_CHECK_PKCS1_OAEP_MGF1, ERR_R_MALLOC_FAILURE);\n        goto cleanup;\n    }\n    memset(em, 0, num);\n    memcpy(em + num - flen, from, flen);\n    good = constant_time_is_zero(em[0]);\n    maskedseed = em + 1;\n    maskeddb = em + 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    if (!good)\n        goto decoding_err;\n    msg_index = one_index + 1;\n    mlen = dblen - msg_index;\n    if (tlen < mlen) {\n        RSAerr(RSA_F_RSA_PADDING_CHECK_PKCS1_OAEP_MGF1, RSA_R_DATA_TOO_LARGE);\n        mlen = -1;\n    } else {\n        memcpy(to, db + msg_index, mlen);\n        goto cleanup;\n    }\n decoding_err:\n    RSAerr(RSA_F_RSA_PADDING_CHECK_PKCS1_OAEP_MGF1,\n           RSA_R_OAEP_DECODING_ERROR);\n cleanup:\n    OPENSSL_free(db);\n    OPENSSL_free(em);\n    return mlen;\n}', 'int CRYPTO_memcmp(const volatile void * volatile in_a,\n                  const volatile void * volatile in_b,\n                  size_t len)\n{\n    size_t i;\n    const volatile unsigned char *a = in_a;\n    const volatile unsigned char *b = in_b;\n    unsigned char x = 0;\n    for (i = 0; i < len; i++)\n        x |= a[i] ^ b[i];\n    return x;\n}', 'static ossl_inline unsigned int constant_time_is_zero(unsigned int a)\n{\n    return constant_time_msb(~a & (a - 1));\n}']