package stupidgcm import ( "fmt" "log" ) /* #include "openssl_aead.h" #cgo pkg-config: libcrypto */ import "C" func openSSLSeal(a *stupidAEADCommon, dst, iv, in, authData []byte) []byte { if a.Wiped() { panic("BUG: tried to use wiped key") } if len(iv) != a.NonceSize() { log.Panicf("Only %d-byte IVs are supported, you passed %d bytes", a.NonceSize(), len(iv)) } if len(in) == 0 { log.Panic("Zero-length input data is not supported") } // If the "dst" slice is large enough we can use it as our output buffer outLen := len(in) + tagLen var buf []byte inplace := false if cap(dst)-len(dst) >= outLen { inplace = true buf = dst[len(dst) : len(dst)+outLen] } else { buf = make([]byte, outLen) } res := int(C.openssl_aead_seal(a.openSSLEVPCipher, (*C.uchar)(&in[0]), C.int(len(in)), (*C.uchar)(&authData[0]), C.int(len(authData)), (*C.uchar)(&a.key[0]), C.int(len(a.key)), (*C.uchar)(&iv[0]), C.int(len(iv)), (*C.uchar)(&buf[0]), C.int(len(buf)))) if res != outLen { log.Panicf("expected length %d, got %d", outLen, res) } if inplace { return dst[:len(dst)+outLen] } return append(dst, buf...) } func openSSLOpen(a *stupidAEADCommon, dst, iv, in, authData []byte) ([]byte, error) { if a.Wiped() { panic("BUG: tried to use wiped key") } if len(iv) != a.NonceSize() { log.Panicf("Only %d-byte IVs are supported, you passed %d bytes", a.NonceSize(), len(iv)) } if len(in) <= tagLen { return nil, fmt.Errorf("stupidChacha20poly1305: input data too short (%d bytes)", len(in)) } // If the "dst" slice is large enough we can use it as our output buffer outLen := len(in) - tagLen var buf []byte inplace := false if cap(dst)-len(dst) >= outLen { inplace = true buf = dst[len(dst) : len(dst)+outLen] } else { buf = make([]byte, len(in)-tagLen) } ciphertext := in[:len(in)-tagLen] tag := in[len(in)-tagLen:] res := int(C.openssl_aead_open(a.openSSLEVPCipher, (*C.uchar)(&ciphertext[0]), C.int(len(ciphertext)), (*C.uchar)(&authData[0]), C.int(len(authData)), (*C.uchar)(&tag[0]), C.int(len(tag)), (*C.uchar)(&a.key[0]), C.int(len(a.key)), (*C.uchar)(&iv[0]), C.int(len(iv)), (*C.uchar)(&buf[0]), C.int(len(buf)))) if res < 0 { return nil, ErrAuth } if res != outLen { log.Panicf("unexpected length %d", res) } if inplace { return dst[:len(dst)+outLen], nil } return append(dst, buf...), nil }