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evp_cipher

API Overview​

EVP_Cipher is an API in openssl. This rule belongs to the return value check type. This rule is generated using AURC.

Rule Description​

tip

EVP_Cipher() returns the amount of encrypted / decrypted bytes, or -1 on failure if the flag B<EVP_CIPH_FLAG_CUSTOM_CIPHER> is set for the cipher. EVP_Cipher() returns 1 on success or 0 on failure, if the flag B<EVP_CIPH_FLAG_CUSTOM_CIPHER> is not set for the cipher.

info
  • Tags: return value check
  • Parameter Index: N/A
  • CWE Type: CWE-253

Rule Code​

import cpp

class OpenSSLFunctionCall extends FunctionCall {
  OpenSSLFunctionCall() {
    this.getTarget().hasName("EVP_Cipher")
  }
}

from OpenSSLFunctionCall call, UnaryOperation uop
where
  uop.getOperator() = "!" and
  uop.getOperand() = call.getAnAccess()
select uop, "This negation checks the return value of EVP_Cipher."