I am trying to implement a RSA cipher using wolfcrypt in an Android App and I was using the code in this thread to do it(https://www.wolfssl.com/forums/topic798-rsa-in-oaep-mode.html). The error I get is that the function wc_RsaPrivateDecrypt_ex always return ret= -236. What can be possibly going wrong? Thank you for your help.
P.S.: The android implementation is not a problem. The error comes completely from C.
#include <jni.h>
#include <android/log.h>
#include <stdio.h>
#include <wolfssl/wolfcrypt/rsa.h>
#include <wolfssl/wolfcrypt/error-crypt.h>
#include <wolfssl/options.h>
#define BITS_TO_BYTES(b) (b/8)
#define MIN_OAEP_PADDING (2*BITS_TO_BYTES(160)+2)
#define RSA_LENGTH (BITS_TO_BYTES(2048))
#define RSA_OAEP_DECRYPTED_DATA_LENGTH (RSA_LENGTH-MIN_OAEP_PADDING)
#define RSA_OAEP_ENCRYPTED_DATA_LENGTH (RSA_LENGTH)
JNIEXPORT void JNICALL
Java_com_wolfssl_wolfssljni_1ndk_1gradle_MainActivity_prueba(JNIEnv *env, jobject instance) {
RsaKey key;
RNG rng;
word32 index;
int ret;
int encrypted_len;
int decrypted_len;
char str[] = "String to be encrypted";
strcpy(in_buffer,str);
// encrypt data.
index = 0;
ret = wc_InitRng(&rng);
if (ret != 0) { LOGD("Error at wc_InitRng: %i.", ret); return; }
ret = wc_InitRsaKey(&key, NULL);
if (ret != 0) { LOGD("Error at wc_InitRsaKey: %i.", ret); return; }
ret = wc_RsaPublicKeyDecode((const byte*)public_key, &index, &key, PUBLIC_KEY_LENGTH);
if (ret != 0) { LOGD("Error at wc_RsaPublicKeyDecode: %i.", ret); return; }
ret = wc_RsaPublicEncrypt_ex((const byte *)in_buffer, IN_BUFFER_LENGTH, (byte*)encrypted_buffer, RSA_LENGTH, &key, &rng, WC_RSA_OAEP_PAD, WC_HASH_TYPE_SHA, WC_MGF1SHA1, NULL, 0);
if (ret < 0) { LOGD("Error at wc_RsaPublicEncrypt_ex: %i.", ret); return; }
LOGD("Good encryption");
LOGD("RET: %i", ret);
encrypted_len = ret;
wc_FreeRng(&rng);
wc_FreeRsaKey(&key);
// decrypt data.
index = 0;
ret = wc_InitRsaKey(&key, NULL);
if (ret != 0) { LOGD("Error at wc_InitRsaKey: %i.", ret); return; }
ret = wc_RsaPrivateKeyDecode((const byte*)private_key, &index, &key, PRIVATE_KEY_LENGTH);
if (ret != 0) { LOGD("Error at wc_RsaPrivateKeyDecode: %i.", ret); return; }
ret = wc_RsaPrivateDecrypt_ex((const byte *)encrypted_buffer, encrypted_len, (byte*)decrypted_buffer, RSA_LENGTH, &key, WC_RSA_OAEP_PAD, WC_HASH_TYPE_SHA, WC_MGF1SHA1, NULL, 0);
if (ret < 0) { LOGD("Error at wc_RsaPrivateDecrypt_ex: %i.", ret); return; }
decrypted_len = ret;
LOGD("No error");
wc_FreeRsaKey(&key);
// compare data.
if (decrypted_len != IN_BUFFER_LENGTH) { LOGD("Decrypted length should be %i but it is %i.", IN_BUFFER_LENGTH, decrypted_len); return; }
for (int i = 0; i < IN_BUFFER_LENGTH; i++)
{
if (decrypted_buffer[i] != in_buffer[i]) { LOGD("Byte at index %i should be %i but it is %i.", i, 0xFF & in_buffer[i], 0xFF & decrypted_buffer[i]); return; }
}
// got here means no error.
LOGD("All went O.K.");
}
unsigned char private_key[PRIVATE_KEY_LENGTH] = {
0x30, 0x82, 0x04, 0xa2, 0x02, 0x01, 0x00, 0x02,
0x82, 0x01, 0x01, 0x00, 0xc8, 0x40, 0x6f, 0xc7,
0xd0, 0xc9, 0xfb, 0xd2, 0x5c, 0xf3, 0xc5, 0xbc,
0x77, 0x0e, 0x68, 0x5a, 0x87, 0x4a, 0xb9, 0x57,
0x08, 0xd4, 0x6b, 0x3e, 0x9a, 0x89, 0x8a, 0x9f,
0xdd, 0xad, 0x16, 0xa8, 0xa3, 0x82, 0x42, 0x22,
0x5b, 0x69, 0x77, 0x28, 0xba, 0x15, 0x2b, 0xb3,
0xf3, 0x24, 0xea, 0xe4, 0x86, 0x34, 0x73, 0xc1,
0xe5, 0x2b, 0x0b, 0xdb, 0xcd, 0x54, 0x35, 0x55,
0xda, 0xf1, 0xfd, 0x61, 0x3f, 0x1e, 0xe7, 0x1e,
0xf1, 0xc0, 0x38, 0xcb, 0xfc, 0x0d, 0x9d, 0x65,
0xba, 0x50, 0x1f, 0xb7, 0x8d, 0xb3, 0x59, 0x8c,
0x48, 0xf2, 0x34, 0xf1, 0x46, 0x86, 0xab, 0xf2,
0xc0, 0xdd, 0x1c, 0x6d, 0xbe, 0xf9, 0x8f, 0x79,
0xa8, 0x6f, 0x02, 0x25, 0x07, 0xba, 0xc0, 0x91,
0x27, 0x46, 0xfb, 0xc8, 0xe8, 0x78, 0xc0, 0xb4,
0x91, 0xb6, 0xd6, 0x5d, 0xbe, 0x74, 0x00, 0x60,
0x73, 0xe9, 0x0e, 0x10, 0x60, 0x48, 0x82, 0xbf,
0x50, 0x58, 0xc4, 0x6f, 0xf0, 0x4e, 0xcf, 0x92,
0x43, 0x36, 0x75, 0xe5, 0x79, 0xb9, 0x78, 0x81,
0xbc, 0xb6, 0xf5, 0x74, 0xfe, 0x0f, 0x3f, 0xd4,
0x88, 0xfb, 0xe6, 0x4f, 0xd8, 0x8a, 0x60, 0xc9,
0x25, 0xed, 0xa1, 0xef, 0x4a, 0x57, 0x81, 0xb1,
0xce, 0xaf, 0x3d, 0xcf, 0x2a, 0x44, 0x51, 0x76,
0x16, 0x54, 0x3d, 0x4b, 0x77, 0x09, 0x39, 0x6c,
0x85, 0xc5, 0x0c, 0x59, 0x49, 0x12, 0xba, 0x3f,
0x98, 0x1f, 0x29, 0x16, 0xc6, 0xed, 0x08, 0x09,
0xa9, 0xdc, 0xe4, 0x92, 0x70, 0x71, 0x57, 0x1c,
0xcb, 0xf2, 0xfa, 0x03, 0x84, 0xf0, 0xd8, 0x27,
0xbc, 0xa5, 0x0a, 0x95, 0x21, 0xbc, 0x87, 0x61,
0x9a, 0xfd, 0x78, 0xab, 0xe3, 0x2f, 0xef, 0x16,
0x86, 0x5b, 0xe7, 0x8e, 0x48, 0xef, 0x3c, 0xa1,
0x6e, 0xd6, 0xe7, 0xda, 0x4c, 0x69, 0x5c, 0x4f,
0x7a, 0x20, 0x58, 0x1d, 0x02, 0x03, 0x01, 0x00,
0x01, 0x02, 0x82, 0x01, 0x00, 0x78, 0xd8, 0xda,
0x1c, 0x5d, 0xd5, 0xe7, 0x10, 0x96, 0x63, 0xce,
0x8a, 0xe3, 0xd6, 0x60, 0x07, 0x71, 0xea, 0x18,
0x5b, 0x7b, 0xca, 0xa5, 0x45, 0xcc, 0x81, 0x00,
0x95, 0x65, 0x73, 0xd5, 0x5e, 0xc3, 0xfe, 0x11,
0xe7, 0x25, 0xff, 0x49, 0x97, 0xdc, 0x64, 0x76,
0x51, 0x4c, 0x84, 0x94, 0xf4, 0x80, 0x41, 0x1b,
0x32, 0x82, 0x18, 0x2e, 0x39, 0xe1, 0x79, 0xd6,
0x0e, 0x0f, 0xe9, 0x45, 0x9d, 0xf0, 0x37, 0xb8,
0x06, 0xa6, 0xa1, 0xf8, 0x24, 0xb1, 0xe1, 0x8d,
0x81, 0x1c, 0xa4, 0xc9, 0xdf, 0x3d, 0xb6, 0x64,
0x6e, 0x12, 0x7f, 0x88, 0x8f, 0xaa, 0x9e, 0x0f,
0x1a, 0x9a, 0x65, 0x55, 0x88, 0xad, 0x5d, 0x71,
0xc6, 0x5b, 0x6d, 0x52, 0x80, 0x02, 0x60, 0x23,
0x61, 0xf5, 0xb0, 0x12, 0xb6, 0xb6, 0x04, 0x59,
0x57, 0x1f, 0x30, 0x95, 0xc1, 0x50, 0xf4, 0x34,
0x5e, 0x00, 0xd5, 0x3e, 0x54, 0x76, 0x5e, 0xd4,
0x26, 0xf8, 0xa7, 0x93, 0xf8, 0xe9, 0x67, 0xcc,
0xf9, 0x04, 0x8e, 0xcb, 0x3f, 0x5e, 0xde, 0x89,
0xc5, 0x9b, 0x80, 0x88, 0xfc, 0xef, 0xc1, 0x30,
0xc4, 0x69, 0xb4, 0xde, 0xfc, 0x2c, 0x29, 0x18,
0x89, 0x8e, 0xca, 0x93, 0xfd, 0x4a, 0x2c, 0x2e,
0x75, 0x7f, 0x61, 0xd6, 0xcb, 0xd0, 0x8a, 0xfe,
0x79, 0xf6, 0x47, 0x47, 0x9a, 0x6d, 0xb7, 0x27,
0xf0, 0x75, 0x9e, 0x26, 0xd3, 0xd0, 0x3e, 0x54,
0x3c, 0x19, 0x94, 0xa7, 0x9a, 0x79, 0xb8, 0x8e,
0x6f, 0xa6, 0x2a, 0xba, 0x84, 0x89, 0x04, 0xc3,
0x92, 0x16, 0xd1, 0x21, 0x5b, 0x0b, 0x59, 0x00,
0xe7, 0x98, 0x63, 0x21, 0x85, 0x36, 0x88, 0x9b,
0x7d, 0x8f, 0x9b, 0x41, 0x20, 0x52, 0x79, 0x2d,
0x33, 0xb6, 0x85, 0xd1, 0xf4, 0x2e, 0x86, 0x88,
0x60, 0xa7, 0xda, 0xa1, 0x2b, 0x2f, 0x82, 0xe1,
0x3e, 0xba, 0x49, 0x31, 0xc9, 0x02, 0x81, 0x81,
0x00, 0xe3, 0x51, 0xb6, 0x11, 0xb7, 0x61, 0x34,
0x60, 0x73, 0xe1, 0xa0, 0x92, 0x25, 0x96, 0x36,
0x79, 0x89, 0xbc, 0x22, 0x28, 0xcb, 0xcd, 0x2f,
0x51, 0x15, 0xa4, 0x44, 0xb8, 0x2f, 0xf4, 0xea,
0x07, 0x5f, 0xf0, 0x54, 0x7e, 0x72, 0x5f, 0xe9,
0xe1, 0xec, 0xa2, 0xc9, 0x34, 0x12, 0x30, 0xa7,
0xe1, 0xd0, 0x63, 0xbe, 0x64, 0xcc, 0x97, 0x98,
0xdc, 0xff, 0xbe, 0xd7, 0x24, 0xab, 0x7c, 0x27,
0x3d, 0x4f, 0x76, 0x46, 0x10, 0xb2, 0x29, 0xc5,
0x6e, 0xbe, 0x27, 0x40, 0xf0, 0xfe, 0x33, 0xbe,
0x84, 0x98, 0xe0, 0x5a, 0x6c, 0x17, 0xbf, 0xa1,
0x1d, 0x07, 0x52, 0xb0, 0x28, 0x3c, 0xa6, 0x51,
0x39, 0xc3, 0xb7, 0xb5, 0x6b, 0xcf, 0x8a, 0xa1,
0x99, 0x94, 0x4d, 0xe1, 0x76, 0x17, 0x09, 0x18,
0xe8, 0x5e, 0x5f, 0xfa, 0x76, 0x18, 0x70, 0x77,
0x6c, 0x04, 0x9c, 0x80, 0x48, 0x37, 0x7c, 0xfa,
0x17, 0x02, 0x81, 0x81, 0x00, 0xe1, 0x84, 0x75,
0xd3, 0xbe, 0x3b, 0xe6, 0x11, 0x71, 0xe2, 0x56,
0xd4, 0x31, 0xb8, 0x04, 0x66, 0xc2, 0x29, 0xa2,
0x14, 0x16, 0x81, 0xa2, 0xd7, 0x47, 0x20, 0x9a,
0xd6, 0x2a, 0x98, 0x8e, 0x01, 0x61, 0x12, 0x41,
0xb6, 0xd7, 0x34, 0x7a, 0xc8, 0x07, 0x34, 0xe4,
0x2f, 0x4c, 0xb9, 0xe3, 0x72, 0xa8, 0x16, 0xed,
0x36, 0xfb, 0x18, 0xd7, 0x87, 0xa2, 0xff, 0x6a,
0xfe, 0xde, 0x37, 0x5d, 0x1a, 0x45, 0xb1, 0x16,
0x0a, 0x2c, 0x35, 0xab, 0x6e, 0xc1, 0x12, 0xac,
0x7d, 0xe3, 0x7a, 0xd9, 0xc1, 0xda, 0xaa, 0x36,
0xdc, 0xc8, 0x03, 0x30, 0x39, 0x59, 0xe6, 0x85,
0x4e, 0x6b, 0xd2, 0x2d, 0xbf, 0xb8, 0xb4, 0x45,
0xb1, 0x6b, 0xf4, 0xcf, 0x41, 0x4d, 0xab, 0x5c,
0x29, 0x81, 0x4b, 0x87, 0x57, 0xf1, 0x0a, 0x6e,
0x2d, 0x40, 0x80, 0x31, 0xc3, 0x1b, 0xdc, 0xc0,
0x78, 0x3a, 0x1b, 0x83, 0xeb, 0x02, 0x81, 0x80,
0x78, 0x37, 0x87, 0x65, 0x39, 0x28, 0xf4, 0x0d,
0x2a, 0x5b, 0xa1, 0x92, 0x88, 0xc4, 0x37, 0x0c,
0xf1, 0x95, 0x88, 0x2f, 0x31, 0x10, 0xd3, 0x3c,
0x3b, 0x88, 0xc3, 0x3a, 0xf1, 0x49, 0xc1, 0xd6,
0xa2, 0x9b, 0x33, 0xe4, 0x27, 0x52, 0xa8, 0x1a,
0xee, 0x0d, 0x6d, 0x00, 0xd7, 0xb9, 0xd9, 0x9f,
0x27, 0x99, 0x08, 0x60, 0xc0, 0x7e, 0x4f, 0xbe,
0x58, 0x96, 0x31, 0xab, 0x57, 0xf1, 0x71, 0xc3,
0x0f, 0xda, 0x09, 0xd5, 0xdc, 0x93, 0x10, 0xb1,
0xaf, 0x68, 0x8d, 0x04, 0xa6, 0x3a, 0xf1, 0x3f,
0xa8, 0xa5, 0xc5, 0xcc, 0x32, 0x87, 0x0a, 0x8a,
0x92, 0x8b, 0xdd, 0x53, 0x7a, 0x37, 0xae, 0xef,
0x30, 0x9d, 0x60, 0x19, 0xa3, 0x09, 0xba, 0xca,
0xc0, 0xce, 0xab, 0x34, 0xcb, 0x9b, 0xe9, 0x0b,
0x42, 0x95, 0xd9, 0x9c, 0x48, 0xf2, 0x79, 0x85,
0xab, 0xae, 0xa4, 0x7d, 0x0c, 0xb3, 0x50, 0x83,
0x02, 0x81, 0x80, 0x35, 0xc9, 0x91, 0x0c, 0xca,
0xaf, 0xa0, 0xa5, 0x02, 0x83, 0x98, 0x70, 0x0d,
0xd7, 0xb4, 0xfd, 0x09, 0x4c, 0x42, 0xc3, 0x05,
0xc7, 0x2f, 0x9e, 0xa6, 0xf1, 0x48, 0xdc, 0xd1,
0xd6, 0x06, 0xf0, 0x9f, 0x45, 0x6a, 0x75, 0x00,
0x89, 0x1c, 0xcb, 0xbe, 0xa4, 0x47, 0xd4, 0x5c,
0x39, 0x6d, 0xdd, 0x37, 0xe8, 0x17, 0xf5, 0xe8,
0x17, 0xb9, 0xb8, 0x39, 0x11, 0x30, 0x64, 0xcf,
0x7d, 0x66, 0xf0, 0x50, 0x34, 0xf7, 0x6b, 0xbf,
0xb5, 0xa1, 0x48, 0xce, 0x35, 0xf4, 0xfc, 0x25,
0x98, 0x74, 0x7d, 0x7e, 0xf8, 0xe0, 0x12, 0xf2,
0x85, 0x88, 0x27, 0xf5, 0xa0, 0x3c, 0xa5, 0x42,
0xa4, 0x23, 0x93, 0x39, 0xab, 0x8d, 0x7f, 0xce,
0x9e, 0xda, 0x1b, 0xda, 0x39, 0x87, 0xc6, 0xc2,
0x76, 0xd0, 0x36, 0x12, 0x60, 0x89, 0x7c, 0xb3,
0x88, 0x9f, 0xd5, 0xc8, 0x3c, 0x73, 0x8f, 0x79,
0x54, 0x7c, 0xb7, 0x02, 0x81, 0x80, 0x20, 0x31,
0x41, 0x4c, 0xa4, 0xc9, 0x99, 0xd1, 0x0c, 0x83,
0x2b, 0x94, 0x30, 0x1c, 0x25, 0x92, 0x84, 0x2c,
0x16, 0x0e, 0xcf, 0x2b, 0x3b, 0x7b, 0x92, 0x2b,
0x5d, 0xae, 0x46, 0x82, 0xf1, 0x7f, 0xc1, 0x42,
0x1b, 0x96, 0x12, 0x01, 0x1d, 0x62, 0x29, 0xe5,
0x8d, 0x4c, 0xa8, 0xf4, 0x47, 0x02, 0x9a, 0x92,
0x65, 0x27, 0xbd, 0x49, 0x12, 0xd2, 0xc6, 0xcc,
0xc7, 0x2b, 0x18, 0x02, 0x90, 0x4a, 0xd6, 0x65,
0x6f, 0x2a, 0x3c, 0x40, 0x68, 0xf5, 0x36, 0x70,
0xd4, 0x52, 0x82, 0xae, 0xa8, 0xa2, 0x38, 0xc0,
0x00, 0x13, 0x5f, 0x15, 0x45, 0x1a, 0x95, 0x17,
0xc1, 0x62, 0x9e, 0xc8, 0xe3, 0xe2, 0xc4, 0xf7,
0xbf, 0xaa, 0xef, 0xfb, 0x15, 0xde, 0xa8, 0xa9,
0x64, 0x3e, 0x0e, 0x5a, 0xa0, 0x12, 0x7d, 0x0d,
0x5b, 0xb1, 0xef, 0xf3, 0xaf, 0xed, 0x8f, 0x5b,
0xd8, 0xb3, 0xbc, 0xa1, 0x35, 0xd1
};
unsigned char public_key[PUBLIC_KEY_LENGTH] = {
0x30, 0x82, 0x01, 0x22, 0x30, 0x0d, 0x06, 0x09,
0x2a, 0x86, 0x48, 0x86, 0xf7, 0x0d, 0x01, 0x01,
0x01, 0x05, 0x00, 0x03, 0x82, 0x01, 0x0f, 0x00,
0x30, 0x82, 0x01, 0x0a, 0x02, 0x82, 0x01, 0x01,
0x00, 0xc8, 0x40, 0x6f, 0xc7, 0xd0, 0xc9, 0xfb,
0xd2, 0x5c, 0xf3, 0xc5, 0xbc, 0x77, 0x0e, 0x68,
0x5a, 0x87, 0x4a, 0xb9, 0x57, 0x08, 0xd4, 0x6b,
0x3e, 0x9a, 0x89, 0x8a, 0x9f, 0xdd, 0xad, 0x16,
0xa8, 0xa3, 0x82, 0x42, 0x22, 0x5b, 0x69, 0x77,
0x28, 0xba, 0x15, 0x2b, 0xb3, 0xf3, 0x24, 0xea,
0xe4, 0x86, 0x34, 0x73, 0xc1, 0xe5, 0x2b, 0x0b,
0xdb, 0xcd, 0x54, 0x35, 0x55, 0xda, 0xf1, 0xfd,
0x61, 0x3f, 0x1e, 0xe7, 0x1e, 0xf1, 0xc0, 0x38,
0xcb, 0xfc, 0x0d, 0x9d, 0x65, 0xba, 0x50, 0x1f,
0xb7, 0x8d, 0xb3, 0x59, 0x8c, 0x48, 0xf2, 0x34,
0xf1, 0x46, 0x86, 0xab, 0xf2, 0xc0, 0xdd, 0x1c,
0x6d, 0xbe, 0xf9, 0x8f, 0x79, 0xa8, 0x6f, 0x02,
0x25, 0x07, 0xba, 0xc0, 0x91, 0x27, 0x46, 0xfb,
0xc8, 0xe8, 0x78, 0xc0, 0xb4, 0x91, 0xb6, 0xd6,
0x5d, 0xbe, 0x74, 0x00, 0x60, 0x73, 0xe9, 0x0e,
0x10, 0x60, 0x48, 0x82, 0xbf, 0x50, 0x58, 0xc4,
0x6f, 0xf0, 0x4e, 0xcf, 0x92, 0x43, 0x36, 0x75,
0xe5, 0x79, 0xb9, 0x78, 0x81, 0xbc, 0xb6, 0xf5,
0x74, 0xfe, 0x0f, 0x3f, 0xd4, 0x88, 0xfb, 0xe6,
0x4f, 0xd8, 0x8a, 0x60, 0xc9, 0x25, 0xed, 0xa1,
0xef, 0x4a, 0x57, 0x81, 0xb1, 0xce, 0xaf, 0x3d,
0xcf, 0x2a, 0x44, 0x51, 0x76, 0x16, 0x54, 0x3d,
0x4b, 0x77, 0x09, 0x39, 0x6c, 0x85, 0xc5, 0x0c,
0x59, 0x49, 0x12, 0xba, 0x3f, 0x98, 0x1f, 0x29,
0x16, 0xc6, 0xed, 0x08, 0x09, 0xa9, 0xdc, 0xe4,
0x92, 0x70, 0x71, 0x57, 0x1c, 0xcb, 0xf2, 0xfa,
0x03, 0x84, 0xf0, 0xd8, 0x27, 0xbc, 0xa5, 0x0a,
0x95, 0x21, 0xbc, 0x87, 0x61, 0x9a, 0xfd, 0x78,
0xab, 0xe3, 0x2f, 0xef, 0x16, 0x86, 0x5b, 0xe7,
0x8e, 0x48, 0xef, 0x3c, 0xa1, 0x6e, 0xd6, 0xe7,
0xda, 0x4c, 0x69, 0x5c, 0x4f, 0x7a, 0x20, 0x58,
0x1d, 0x02, 0x03, 0x01, 0x00, 0x01
};