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stupidgcm: print openssl error stack before panicing

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This commit is contained in:
Jakob Unterwurzacher 2016-05-04 20:50:13 +02:00
parent 6c010c3080
commit d0945b73d2
1 changed files with 31 additions and 15 deletions
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46
internal/stupidgcm/stupidgcm.go
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@ -3,6 +3,7 @@
package stupidgcm
// #include <openssl/evp.h>
// #include <openssl/err.h>
// #cgo pkg-config: libcrypto
import "C"
@ -18,6 +19,21 @@ const (
tagLen = 16
)
func opensslPanic(msg string) {
for {
e := C.ERR_get_error()
if e == 0 {
break
}
log.Printf("openssl error: %d:%s:%s:%s", e,
C.GoString(C.ERR_lib_error_string(e)),
C.GoString(C.ERR_func_error_string(e)),
C.GoString(C.ERR_reason_error_string(e)))
}
log.Printf("(no further openssl error messages)")
log.Panic(msg)
}
// stupidGCM implements the cipher.AEAD interface
type stupidGCM struct {
key []byte
@ -53,28 +69,28 @@ func (g stupidGCM) Seal(dst, iv, in, authData []byte) []byte {
// Create scratch space "context"
ctx := C.EVP_CIPHER_CTX_new()
if ctx == nil {
log.Panic("EVP_CIPHER_CTX_new failed")
opensslPanic("EVP_CIPHER_CTX_new failed")
}
// Set cipher to AES-256
if C.EVP_EncryptInit_ex(ctx, C.EVP_aes_256_gcm(), nil, nil, nil) != 1 {
log.Panic("EVP_EncryptInit_ex I failed")
opensslPanic("EVP_EncryptInit_ex I failed")
}
// Use 16-byte IV
if C.EVP_CIPHER_CTX_ctrl(ctx, C.EVP_CTRL_GCM_SET_IVLEN, ivLen, nil) != 1 {
log.Panic("EVP_CIPHER_CTX_ctrl EVP_CTRL_GCM_SET_IVLEN failed")
opensslPanic("EVP_CIPHER_CTX_ctrl EVP_CTRL_GCM_SET_IVLEN failed")
}
// Set key and IV
if C.EVP_EncryptInit_ex(ctx, nil, nil, (*C.uchar)(&g.key[0]), (*C.uchar)(&iv[0])) != 1 {
log.Panic("EVP_EncryptInit_ex II failed")
opensslPanic("EVP_EncryptInit_ex II failed")
}
// Provide authentication data
var resultLen C.int
if C.EVP_EncryptUpdate(ctx, nil, &resultLen, (*C.uchar)(&authData[0]), C.int(len(authData))) != 1 {
log.Panic("EVP_EncryptUpdate authData failed")
opensslPanic("EVP_EncryptUpdate authData failed")
}
if int(resultLen) != len(authData) {
log.Panicf("Unexpected length %d", resultLen)
@ -82,7 +98,7 @@ func (g stupidGCM) Seal(dst, iv, in, authData []byte) []byte {
// Encrypt "in" into "buf"
if C.EVP_EncryptUpdate(ctx, (*C.uchar)(&buf[0]), &resultLen, (*C.uchar)(&in[0]), C.int(len(in))) != 1 {
log.Panic("EVP_EncryptUpdate failed")
opensslPanic("EVP_EncryptUpdate failed")
}
if int(resultLen) != len(in) {
log.Panicf("Unexpected length %d", resultLen)
@ -92,7 +108,7 @@ func (g stupidGCM) Seal(dst, iv, in, authData []byte) []byte {
// Because GCM is a stream encryption, this will not write out any data.
dummy := make([]byte, 16)
if C.EVP_EncryptFinal_ex(ctx, (*C.uchar)(&dummy[0]), &resultLen) != 1 {
log.Panic("EVP_EncryptFinal_ex failed")
opensslPanic("EVP_EncryptFinal_ex failed")
}
if resultLen != 0 {
log.Panicf("Unexpected length %d", resultLen)
@ -100,7 +116,7 @@ func (g stupidGCM) Seal(dst, iv, in, authData []byte) []byte {
// Get GMAC tag and append it to the ciphertext in "buf"
if C.EVP_CIPHER_CTX_ctrl(ctx, C.EVP_CTRL_GCM_GET_TAG, tagLen, (unsafe.Pointer)(&buf[len(in)])) != 1 {
log.Panic("EVP_CIPHER_CTX_ctrl EVP_CTRL_GCM_GET_TAG failed")
opensslPanic("EVP_CIPHER_CTX_ctrl EVP_CTRL_GCM_GET_TAG failed")
}
// Free scratch space
@ -126,28 +142,28 @@ func (g stupidGCM) Open(dst, iv, in, authData []byte) ([]byte, error) {
// Create scratch space "context"
ctx := C.EVP_CIPHER_CTX_new()
if ctx == nil {
log.Panic("EVP_CIPHER_CTX_new failed")
opensslPanic("EVP_CIPHER_CTX_new failed")
}
// Set cipher to AES-256
if C.EVP_DecryptInit_ex(ctx, C.EVP_aes_256_gcm(), nil, nil, nil) != 1 {
log.Panic("EVP_DecryptInit_ex I failed")
opensslPanic("EVP_DecryptInit_ex I failed")
}
// Use 16-byte IV
if C.EVP_CIPHER_CTX_ctrl(ctx, C.EVP_CTRL_GCM_SET_IVLEN, ivLen, nil) != 1 {
log.Panic("EVP_CIPHER_CTX_ctrl EVP_CTRL_GCM_SET_IVLEN failed")
opensslPanic("EVP_CIPHER_CTX_ctrl EVP_CTRL_GCM_SET_IVLEN failed")
}
// Set key and IV
if C.EVP_DecryptInit_ex(ctx, nil, nil, (*C.uchar)(&g.key[0]), (*C.uchar)(&iv[0])) != 1 {
log.Panic("EVP_DecryptInit_ex II failed")
opensslPanic("EVP_DecryptInit_ex II failed")
}
// Provide authentication data
var resultLen C.int
if C.EVP_DecryptUpdate(ctx, nil, &resultLen, (*C.uchar)(&authData[0]), C.int(len(authData))) != 1 {
log.Panic("EVP_DecryptUpdate authData failed")
opensslPanic("EVP_DecryptUpdate authData failed")
}
if int(resultLen) != len(authData) {
log.Panicf("Unexpected length %d", resultLen)
@ -155,7 +171,7 @@ func (g stupidGCM) Open(dst, iv, in, authData []byte) ([]byte, error) {
// Decrypt "ciphertext" into "buf"
if C.EVP_DecryptUpdate(ctx, (*C.uchar)(&buf[0]), &resultLen, (*C.uchar)(&ciphertext[0]), C.int(len(ciphertext))) != 1 {
log.Panic("EVP_DecryptUpdate failed")
opensslPanic("EVP_DecryptUpdate failed")
}
if int(resultLen) != len(ciphertext) {
log.Panicf("Unexpected length %d", resultLen)
@ -163,7 +179,7 @@ func (g stupidGCM) Open(dst, iv, in, authData []byte) ([]byte, error) {
// Set expected GMAC tag
if C.EVP_CIPHER_CTX_ctrl(ctx, C.EVP_CTRL_GCM_SET_TAG, tagLen, (unsafe.Pointer)(&tag[0])) != 1 {
log.Panic("EVP_CIPHER_CTX_ctrl failed")
opensslPanic("EVP_CIPHER_CTX_ctrl failed")
}
// Check GMAC