int PEM_read_bio()

in Sources/CCryptoBoringSSL/crypto/pem/pem_lib.c [588:756]

• 154 lines of code
• 39 McCabe index (conditional complexity)

int PEM_read_bio(BIO *bp, char **name, char **header, unsigned char **data,
                 long *len)
{
    EVP_ENCODE_CTX ctx;
    int end = 0, i, k, bl = 0, hl = 0, nohead = 0;
    char buf[256];
    BUF_MEM *nameB;
    BUF_MEM *headerB;
    BUF_MEM *dataB, *tmpB;

    nameB = BUF_MEM_new();
    headerB = BUF_MEM_new();
    dataB = BUF_MEM_new();
    if ((nameB == NULL) || (headerB == NULL) || (dataB == NULL)) {
        BUF_MEM_free(nameB);
        BUF_MEM_free(headerB);
        BUF_MEM_free(dataB);
        OPENSSL_PUT_ERROR(PEM, ERR_R_MALLOC_FAILURE);
        return (0);
    }

    buf[254] = '\0';
    for (;;) {
        i = BIO_gets(bp, buf, 254);

        if (i <= 0) {
            OPENSSL_PUT_ERROR(PEM, PEM_R_NO_START_LINE);
            goto err;
        }

        while ((i >= 0) && (buf[i] <= ' '))
            i--;
        buf[++i] = '\n';
        buf[++i] = '\0';

        if (strncmp(buf, "-----BEGIN ", 11) == 0) {
            i = strlen(&(buf[11]));

            if (strncmp(&(buf[11 + i - 6]), "-----\n", 6) != 0)
                continue;
            if (!BUF_MEM_grow(nameB, i + 9)) {
                OPENSSL_PUT_ERROR(PEM, ERR_R_MALLOC_FAILURE);
                goto err;
            }
            OPENSSL_memcpy(nameB->data, &(buf[11]), i - 6);
            nameB->data[i - 6] = '\0';
            break;
        }
    }
    hl = 0;
    if (!BUF_MEM_grow(headerB, 256)) {
        OPENSSL_PUT_ERROR(PEM, ERR_R_MALLOC_FAILURE);
        goto err;
    }
    headerB->data[0] = '\0';
    for (;;) {
        i = BIO_gets(bp, buf, 254);
        if (i <= 0)
            break;

        while ((i >= 0) && (buf[i] <= ' '))
            i--;
        buf[++i] = '\n';
        buf[++i] = '\0';

        if (buf[0] == '\n')
            break;
        if (!BUF_MEM_grow(headerB, hl + i + 9)) {
            OPENSSL_PUT_ERROR(PEM, ERR_R_MALLOC_FAILURE);
            goto err;
        }
        if (strncmp(buf, "-----END ", 9) == 0) {
            nohead = 1;
            break;
        }
        OPENSSL_memcpy(&(headerB->data[hl]), buf, i);
        headerB->data[hl + i] = '\0';
        hl += i;
    }

    bl = 0;
    if (!BUF_MEM_grow(dataB, 1024)) {
        OPENSSL_PUT_ERROR(PEM, ERR_R_MALLOC_FAILURE);
        goto err;
    }
    dataB->data[0] = '\0';
    if (!nohead) {
        for (;;) {
            i = BIO_gets(bp, buf, 254);
            if (i <= 0)
                break;

            while ((i >= 0) && (buf[i] <= ' '))
                i--;
            buf[++i] = '\n';
            buf[++i] = '\0';

            if (i != 65)
                end = 1;
            if (strncmp(buf, "-----END ", 9) == 0)
                break;
            if (i > 65)
                break;
            if (!BUF_MEM_grow_clean(dataB, i + bl + 9)) {
                OPENSSL_PUT_ERROR(PEM, ERR_R_MALLOC_FAILURE);
                goto err;
            }
            OPENSSL_memcpy(&(dataB->data[bl]), buf, i);
            dataB->data[bl + i] = '\0';
            bl += i;
            if (end) {
                buf[0] = '\0';
                i = BIO_gets(bp, buf, 254);
                if (i <= 0)
                    break;

                while ((i >= 0) && (buf[i] <= ' '))
                    i--;
                buf[++i] = '\n';
                buf[++i] = '\0';

                break;
            }
        }
    } else {
        tmpB = headerB;
        headerB = dataB;
        dataB = tmpB;
        bl = hl;
    }
    i = strlen(nameB->data);
    if ((strncmp(buf, "-----END ", 9) != 0) ||
        (strncmp(nameB->data, &(buf[9]), i) != 0) ||
        (strncmp(&(buf[9 + i]), "-----\n", 6) != 0)) {
        OPENSSL_PUT_ERROR(PEM, PEM_R_BAD_END_LINE);
        goto err;
    }

    EVP_DecodeInit(&ctx);
    i = EVP_DecodeUpdate(&ctx,
                         (unsigned char *)dataB->data, &bl,
                         (unsigned char *)dataB->data, bl);
    if (i < 0) {
        OPENSSL_PUT_ERROR(PEM, PEM_R_BAD_BASE64_DECODE);
        goto err;
    }
    i = EVP_DecodeFinal(&ctx, (unsigned char *)&(dataB->data[bl]), &k);
    if (i < 0) {
        OPENSSL_PUT_ERROR(PEM, PEM_R_BAD_BASE64_DECODE);
        goto err;
    }
    bl += k;

    if (bl == 0)
        goto err;
    *name = nameB->data;
    *header = headerB->data;
    *data = (unsigned char *)dataB->data;
    *len = bl;
    OPENSSL_free(nameB);
    OPENSSL_free(headerB);
    OPENSSL_free(dataB);
    return (1);
 err:
    BUF_MEM_free(nameB);
    BUF_MEM_free(headerB);
    BUF_MEM_free(dataB);
    return (0);
}