| /* Simple AES GCM test program, uses the same NIST data used for the FIPS |
| * self test but uses the application level EVP APIs. |
| */ |
| #include <stdio.h> |
| #include <openssl/bio.h> |
| #include <openssl/evp.h> |
| |
| /* AES-GCM test data from NIST public test vectors */ |
| |
| static const unsigned char gcm_key[] = { |
| 0xee,0xbc,0x1f,0x57,0x48,0x7f,0x51,0x92,0x1c,0x04,0x65,0x66, |
| 0x5f,0x8a,0xe6,0xd1,0x65,0x8b,0xb2,0x6d,0xe6,0xf8,0xa0,0x69, |
| 0xa3,0x52,0x02,0x93,0xa5,0x72,0x07,0x8f |
| }; |
| |
| static const unsigned char gcm_iv[] = { |
| 0x99,0xaa,0x3e,0x68,0xed,0x81,0x73,0xa0,0xee,0xd0,0x66,0x84 |
| }; |
| |
| static const unsigned char gcm_pt[] = { |
| 0xf5,0x6e,0x87,0x05,0x5b,0xc3,0x2d,0x0e,0xeb,0x31,0xb2,0xea, |
| 0xcc,0x2b,0xf2,0xa5 |
| }; |
| |
| static const unsigned char gcm_aad[] = { |
| 0x4d,0x23,0xc3,0xce,0xc3,0x34,0xb4,0x9b,0xdb,0x37,0x0c,0x43, |
| 0x7f,0xec,0x78,0xde |
| }; |
| |
| static const unsigned char gcm_ct[] = { |
| 0xf7,0x26,0x44,0x13,0xa8,0x4c,0x0e,0x7c,0xd5,0x36,0x86,0x7e, |
| 0xb9,0xf2,0x17,0x36 |
| }; |
| |
| static const unsigned char gcm_tag[] = { |
| 0x67,0xba,0x05,0x10,0x26,0x2a,0xe4,0x87,0xd7,0x37,0xee,0x62, |
| 0x98,0xf7,0x7e,0x0c |
| }; |
| |
| void aes_gcm_encrypt(void) |
| { |
| EVP_CIPHER_CTX *ctx; |
| int outlen, tmplen; |
| unsigned char outbuf[1024]; |
| printf("AES GCM Encrypt:\n"); |
| printf("Plaintext:\n"); |
| BIO_dump_fp(stdout, gcm_pt, sizeof(gcm_pt)); |
| ctx = EVP_CIPHER_CTX_new(); |
| /* Set cipher type and mode */ |
| EVP_EncryptInit_ex(ctx, EVP_aes_256_gcm(), NULL, NULL, NULL); |
| /* Set IV length if default 96 bits is not appropriate */ |
| EVP_CIPHER_CTX_ctrl(ctx, EVP_CTRL_GCM_SET_IVLEN, sizeof(gcm_iv), NULL); |
| /* Initialise key and IV */ |
| EVP_EncryptInit_ex(ctx, NULL, NULL, gcm_key, gcm_iv); |
| /* Zero or more calls to specify any AAD */ |
| EVP_EncryptUpdate(ctx, NULL, &outlen, gcm_aad, sizeof(gcm_aad)); |
| /* Encrypt plaintext */ |
| EVP_EncryptUpdate(ctx, outbuf, &outlen, gcm_pt, sizeof(gcm_pt)); |
| /* Output encrypted block */ |
| printf("Ciphertext:\n"); |
| BIO_dump_fp(stdout, outbuf, outlen); |
| /* Finalise: note get no output for GCM */ |
| EVP_EncryptFinal_ex(ctx, outbuf, &outlen); |
| /* Get tag */ |
| EVP_CIPHER_CTX_ctrl(ctx, EVP_CTRL_GCM_GET_TAG, 16, outbuf); |
| /* Output tag */ |
| printf("Tag:\n"); |
| BIO_dump_fp(stdout, outbuf, 16); |
| EVP_CIPHER_CTX_free(ctx); |
| } |
| |
| void aes_gcm_decrypt(void) |
| { |
| EVP_CIPHER_CTX *ctx; |
| int outlen, tmplen, rv; |
| unsigned char outbuf[1024]; |
| printf("AES GCM Derypt:\n"); |
| printf("Ciphertext:\n"); |
| BIO_dump_fp(stdout, gcm_ct, sizeof(gcm_ct)); |
| ctx = EVP_CIPHER_CTX_new(); |
| /* Select cipher */ |
| EVP_DecryptInit_ex(ctx, EVP_aes_256_gcm(), NULL, NULL, NULL); |
| /* Set IV length, omit for 96 bits */ |
| EVP_CIPHER_CTX_ctrl(ctx, EVP_CTRL_GCM_SET_IVLEN, sizeof(gcm_iv), NULL); |
| /* Specify key and IV */ |
| EVP_DecryptInit_ex(ctx, NULL, NULL, gcm_key, gcm_iv); |
| #if 0 |
| /* Set expected tag value. A restriction in OpenSSL 1.0.1c and earlier |
| * required the tag before any AAD or ciphertext */ |
| EVP_CIPHER_CTX_ctrl(ctx, EVP_CTRL_GCM_SET_TAG, sizeof(gcm_tag), gcm_tag); |
| #endif |
| /* Zero or more calls to specify any AAD */ |
| EVP_DecryptUpdate(ctx, NULL, &outlen, gcm_aad, sizeof(gcm_aad)); |
| /* Decrypt plaintext */ |
| EVP_DecryptUpdate(ctx, outbuf, &outlen, gcm_ct, sizeof(gcm_ct)); |
| /* Output decrypted block */ |
| printf("Plaintext:\n"); |
| BIO_dump_fp(stdout, outbuf, outlen); |
| /* Set expected tag value. Works in OpenSSL 1.0.1d and later */ |
| EVP_CIPHER_CTX_ctrl(ctx, EVP_CTRL_GCM_SET_TAG, sizeof(gcm_tag), gcm_tag); |
| /* Finalise: note get no output for GCM */ |
| rv = EVP_DecryptFinal_ex(ctx, outbuf, &outlen); |
| /* Print out return value. If this is not successful authentication |
| * failed and plaintext is not trustworthy. |
| */ |
| printf("Tag Verify %s\n", rv > 0 ? "Successful!" : "Failed!"); |
| EVP_CIPHER_CTX_free(ctx); |
| } |
| |
| int main(int argc, char **argv) |
| { |
| aes_gcm_encrypt(); |
| aes_gcm_decrypt(); |
| } |