我有一个der格式的证书,使用这个命令我生成一个公钥:
der
openssl x509 -inform der -in ejbcacert.cer -noout -pubkey > pub1key.pub
结果是:
-----BEGIN PUBLIC KEY----- MIGfMA0GCSqGSIb3DQEBAQUAA4GNADCBiQKBgQC7vbqajDw4o6gJy8UtmIbkcpnk O3Kwc4qsEnSZp/TR+fQi62F79RHWmwKOtFmwteURgLbj7D/WGuNLGOfa/2vse3G2 eHnHl5CB8ruRX9fBl/KgwCVr2JaEuUm66bBQeP5XeBotdR4cvX38uPYivCDdPjJ1 QWPdspTBKcxeFbccDwIDAQAB -----END PUBLIC KEY-----
我怎样才能获得这样的公钥?来自证书还是来自这个公钥?
ssh-rsa AAAAB3NzaC1yc2EAAAADAQABAAAAgQC7vbqajDw4o6gJy8UtmIbkcpnkO3Kwc4qsEnSZp/TR+fQi62F79RHWmwKOtFmwteURgLbj7D/WGuNLGOfa/2vse3G2eHnHl5CB8ruRX9fBl/KgwCVr2JaEuUm66bBQeP5XeBotdR4cvX38uPYivCDdPjJ1QWPdspTBKcxeFbccDw==
这是通过以下命令获得的:
ssh-keygen -y -f private_key1.pem > public_key1.pub
为了回答我自己的问题,在 openssl 邮件列表上发帖后得到了这个:
这是从 OpenSSL 公钥转换为 OpenSSH 公钥的 C 代码。您可以从此链接获取代码并自行编译:
static unsigned char pSshHeader[11] = { 0x00, 0x00, 0x00, 0x07, 0x73, 0x73, 0x68, 0x2D, 0x72, 0x73, 0x61}; static int SshEncodeBuffer(unsigned char *pEncoding, int bufferLen, unsigned char* pBuffer) { int adjustedLen = bufferLen, index; if (*pBuffer & 0x80) { adjustedLen++; pEncoding[4] = 0; index = 5; } else { index = 4; } pEncoding[0] = (unsigned char) (adjustedLen >> 24); pEncoding[1] = (unsigned char) (adjustedLen >> 16); pEncoding[2] = (unsigned char) (adjustedLen >> 8); pEncoding[3] = (unsigned char) (adjustedLen ); memcpy(&pEncoding[index], pBuffer, bufferLen); return index + bufferLen; } int main(int argc, char** argv) { int iRet = 0; int nLen = 0, eLen = 0; int encodingLength = 0; int index = 0; unsigned char *nBytes = NULL, *eBytes = NULL; unsigned char* pEncoding = NULL; FILE* pFile = NULL; EVP_PKEY *pPubKey = NULL; RSA* pRsa = NULL; BIO *bio, *b64; ERR_load_crypto_strings(); OpenSSL_add_all_algorithms(); if (argc != 3) { printf("usage: %s public_key_file_name ssh_key_description\n", argv[0]); iRet = 1; goto error; } pFile = fopen(argv[1], "rt"); if (!pFile) { printf("Failed to open the given file\n"); iRet = 2; goto error; } pPubKey = PEM_read_PUBKEY(pFile, NULL, NULL, NULL); if (!pPubKey) { printf("Unable to decode public key from the given file: %s\n", ERR_error_string(ERR_get_error(), NULL)); iRet = 3; goto error; } if (EVP_PKEY_type(pPubKey->type) != EVP_PKEY_RSA) { printf("Only RSA public keys are currently supported\n"); iRet = 4; goto error; } pRsa = EVP_PKEY_get1_RSA(pPubKey); if (!pRsa) { printf("Failed to get RSA public key : %s\n", ERR_error_string(ERR_get_error(), NULL)); iRet = 5; goto error; } // reading the modulus nLen = BN_num_bytes(pRsa->n); nBytes = (unsigned char*) malloc(nLen); BN_bn2bin(pRsa->n, nBytes); // reading the public exponent eLen = BN_num_bytes(pRsa->e); eBytes = (unsigned char*) malloc(eLen); BN_bn2bin(pRsa->e, eBytes); encodingLength = 11 + 4 + eLen + 4 + nLen; // correct depending on the MSB of e and N if (eBytes[0] & 0x80) encodingLength++; if (nBytes[0] & 0x80) encodingLength++; pEncoding = (unsigned char*) malloc(encodingLength); memcpy(pEncoding, pSshHeader, 11); index = SshEncodeBuffer(&pEncoding[11], eLen, eBytes); index = SshEncodeBuffer(&pEncoding[11 + index], nLen, nBytes); b64 = BIO_new(BIO_f_base64()); BIO_set_flags(b64, BIO_FLAGS_BASE64_NO_NL); bio = BIO_new_fp(stdout, BIO_NOCLOSE); BIO_printf(bio, "ssh-rsa "); bio = BIO_push(b64, bio); BIO_write(bio, pEncoding, encodingLength); BIO_flush(bio); bio = BIO_pop(b64); BIO_printf(bio, " %s\n", argv[2]); BIO_flush(bio); BIO_free_all(bio); BIO_free(b64); error: if (pFile) fclose(pFile); if (pRsa) RSA_free(pRsa); if (pPubKey) EVP_PKEY_free(pPubKey); if (nBytes) free(nBytes); if (eBytes) free(eBytes); if (pEncoding) free(pEncoding); EVP_cleanup(); ERR_free_strings(); return iRet; }