pkcs_5_alg1 hangs if iterations is 0

[guidovranken]

Prerequisites

• Checked the developer manual
• Checked that your issue isn't already filed: https://github.com/issues?utf8=✓&q=repo%3Alibtom%2Flibtomcrypt
• Checked that your issue isn't related to TomsFastMath's limitation that PK operations can by default only be done with max. 2048bit keys

Description

pkcs_5_alg1 hangs if iterations is 0. It would be better to return an error value in this case.

Steps to Reproduce

#include <tomcrypt.h>

#define CF_CHECK_EQ(expr, res) if ( (expr) != (res) ) { goto end; }
#define CF_CHECK_NE(expr, res) if ( (expr) == (res) ) { goto end; }

int main(void)
{
    const unsigned char password[8] = { 0 };
    const unsigned char salt[8] = { 0 };
    unsigned char out[8];
    unsigned long outLen = sizeof(out);

    CF_CHECK_NE(register_hash(&sha256_desc), -1);

    CF_CHECK_EQ(pkcs_5_alg1(
                password,
                sizeof(password),
                salt,
                0,
                find_hash("sha256"),
                out,
                &outLen), CRYPT_OK);
end:
    return 0;
}

Version

Latest develop branch checkout, Clang, Linux 64 bit.

Additional Information

N/A