

#include <limits.h>
#include <string.h>

#include <openssl/ct.h>
#include <openssl/err.h>
#include <openssl/evp.h>

#include "ct_local.h"


static int ct_base64_decode(const char *in, unsigned char **out)
{
    size_t inlen = strlen(in);
    int outlen, i;
    unsigned char *outbuf = NULL;

    if (inlen == 0) {
        *out = NULL;
        return 0;
    }

    outlen = (inlen / 4) * 3;
    outbuf = OPENSSL_malloc(outlen);
    if (outbuf == NULL)
        goto err;

    outlen = EVP_DecodeBlock(outbuf, (unsigned char *)in, inlen);
    if (outlen < 0) {
        ERR_raise(ERR_LIB_CT, CT_R_BASE64_DECODE_ERROR);
        goto err;
    }

    
    i = 0;
    while (in[--inlen] == '=') {
        --outlen;
        if (++i > 2)
            goto err;
    }

    *out = outbuf;
    return outlen;
err:
    OPENSSL_free(outbuf);
    return -1;
}

SCT *SCT_new_from_base64(unsigned char version, const char *logid_base64,
                         ct_log_entry_type_t entry_type, uint64_t timestamp,
                         const char *extensions_base64,
                         const char *signature_base64)
{
    SCT *sct = SCT_new();
    unsigned char *dec = NULL;
    const unsigned char* p = NULL;
    int declen;

    if (sct == NULL) {
        ERR_raise(ERR_LIB_CT, ERR_R_CT_LIB);
        return NULL;
    }

    
    if (!SCT_set_version(sct, version)) {
        ERR_raise(ERR_LIB_CT, CT_R_SCT_UNSUPPORTED_VERSION);
        goto err;
    }

    declen = ct_base64_decode(logid_base64, &dec);
    if (declen < 0) {
        ERR_raise(ERR_LIB_CT, X509_R_BASE64_DECODE_ERROR);
        goto err;
    }
    if (!SCT_set0_log_id(sct, dec, declen))
        goto err;
    dec = NULL;

    declen = ct_base64_decode(extensions_base64, &dec);
    if (declen < 0) {
        ERR_raise(ERR_LIB_CT, X509_R_BASE64_DECODE_ERROR);
        goto err;
    }
    SCT_set0_extensions(sct, dec, declen);
    dec = NULL;

    declen = ct_base64_decode(signature_base64, &dec);
    if (declen < 0) {
        ERR_raise(ERR_LIB_CT, X509_R_BASE64_DECODE_ERROR);
        goto err;
    }

    p = dec;
    if (o2i_SCT_signature(sct, &p, declen) <= 0)
        goto err;
    OPENSSL_free(dec);
    dec = NULL;

    SCT_set_timestamp(sct, timestamp);

    if (!SCT_set_log_entry_type(sct, entry_type))
        goto err;

    return sct;

 err:
    OPENSSL_free(dec);
    SCT_free(sct);
    return NULL;
}


int CTLOG_new_from_base64_ex(CTLOG **ct_log, const char *pkey_base64,
                             const char *name, OSSL_LIB_CTX *libctx,
                             const char *propq)
{
    unsigned char *pkey_der = NULL;
    int pkey_der_len;
    const unsigned char *p;
    EVP_PKEY *pkey = NULL;

    if (ct_log == NULL) {
        ERR_raise(ERR_LIB_CT, ERR_R_PASSED_INVALID_ARGUMENT);
        return 0;
    }

    pkey_der_len = ct_base64_decode(pkey_base64, &pkey_der);
    if (pkey_der_len < 0) {
        ERR_raise(ERR_LIB_CT, CT_R_LOG_CONF_INVALID_KEY);
        return 0;
    }

    p = pkey_der;
    pkey = d2i_PUBKEY_ex(NULL, &p, pkey_der_len, libctx, propq);
    OPENSSL_free(pkey_der);
    if (pkey == NULL) {
        ERR_raise(ERR_LIB_CT, CT_R_LOG_CONF_INVALID_KEY);
        return 0;
    }

    *ct_log = CTLOG_new_ex(pkey, name, libctx, propq);
    if (*ct_log == NULL) {
        EVP_PKEY_free(pkey);
        return 0;
    }

    return 1;
}

int CTLOG_new_from_base64(CTLOG **ct_log, const char *pkey_base64,
                          const char *name)
{
    return CTLOG_new_from_base64_ex(ct_log, pkey_base64, name, NULL, NULL);
}
